7134 federal register vol. no. thursday, february 21, 1991 ...€¦ · preregistration is required...

7134 Federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

ENVIRONMENTAL PROTECTIONAGENCY40 CFR Parts 260, 261, 264, 265, 266,

270, and 271

[EPA/OSW-FR-91-012; SWH-FRL-3865-61

RIN 2050-AA72Burning of Hazardous Waste In Boilers andIndustrial FurnacesAGENCY: Environmental ProtectionAgency (EPA).ACTION: Final rule.

SUMMARY: Under this final rule, theEnvironmental Protection Agency (EPA]is expanding controls on hazardouswaste combustion to regulate airemissions from the burning of hazardouswaste in boilers and industrial furnaces.Currently. such burning is exempt fromregulation. EPA is promulgating thisfinal rule after considering publiccomment on rules proposed on May 6,1987, plus the comments on EPA'ssupplemental notices of October 26, 1989and April 27, 1990.

These rules control emissions of toxicorganic compounds, toxic metals,hydrogen chloride, chlorine gas, andparticulate matter from boilers andindustrial furnaces burning hazardouswaste. In addition the rules subjectowners and operators of these devicesto the general facility standardsapplicable to hazardous wastetreatment, storage, and disposalfacilities. Further, today's final rulesubjects hazardous waste storage unitsat regulated burner facilities to part 264permit standards. Burner storageoperations at existing facilities aregenerally now subject only to interimstatus standards under part 265.

Finally, today's rule takes final actionon two pending petitions for rulemaking:(1) based on a petition by Dow ChemicalCompany, EPA is designating halogenacid furnaces as industrial furnacesunder § 260.10; and (2) based on apetition by the American Iron and SteelInstitute, EPA is classifying coke andcoal tar fuels produced by recycling coaltar decanter sludge, EPA HazardousWaste No. K087, as products ratherthan solid waste. The rule also makesseveral technical corrections toregulations dealing with loss of interimstatus for facilities that achieved interimstatus as of November 7, 1984.EFFECTIVE DATE: This final rule iseffective on August 21, 1991. Technicalcorrections to § 270.73 are effective onpublication.

The incorporation by reference ofcertain publications listed in theregulations is approved by the Director

of the Federal Register as of August 21,1991.ADDRESSES: The official record for thisrulemaking is identified as DocketNumbers F-87-BBFP-FFFFF and F-89-BBSP-FFFFF, and is located in the EPARCRA Docket, roont 2427, 401 M StreetSW., Washington, DC 20460. The docketis available for inspection from 9 a.m. to4 p.m., Monday through Friday, excepton Federal holidays. The public mustmake an appointment tc review docketmaterials by calling (202) 475-9327. Thepublic may copy up to 100 pages fromthe docket at no charge. Additionalcopies cost $.15 per page.FOR FURTHER INFORMATION CONTACT:For general information contact theRCRA Hotline at: (800) 424-9346 (toll-free) or (703) 920-9810 locally. Forinformation on specific aspects of thisfinal rule, contact Shiva Garg, Office ofSolid Waste (OS-322W), U.S.Environmental Protection Agency, 401 MStreet SW., Washington, DC 20460, (703)308-8460.

EPA is planning to conduct six two-day implementation workshopsbeginning in mid February in thefollowing cities: San Francisco, CA;Dallas, TX; Kansas City, KS; Atlanta,GA; Chicago, IL: and Philadelphia, PA.The purpose of the sessions is to explainresponsibilities of owner/operatorsburning hazardous waste under thisrule. The first day will be open only togovernment representatives involved inimplementation, compliance, andenforcement of these regulations. Thesecond day is open to the public.Preregistration is required to assure areservation. Same day registration willbe allowed as space is available.Interested parties should call 919-549-0722 to obtain further information andget on the mailing list for notices.SUPPLEMENTARY INFORMATION:Preamble OutlinePart One: BackgroundI. Legal Authority.II. Overview of the Final Rule.

A. Controls for Emissions of OrganicCompounds.

B. Controls for Emissions of Toxic Metals.C. Controls for Emissions of Hydrogen

Chloride and Chlorine Gas.D. Emission Standard for Particulate

Matter.E. Permitting Procedures.F. Controls During Interim Status.G. Units Exempt from Air Emissions

Standards.H. Pollution Prevention Impacts.

I1. Relationship to Other Rules.A. Regulations to be Promulgated Under

the New Clean Air Act.B. April 27, 1990 Proposed Incinerator

Amendments.C. July 28, 1990 Proposed Amendment to

Definition of Wastewater Treatment Unitto Exempt Sludge Dryers.

D. Land Disposal Restriction Standards.Part Two: Devices Subject to RegulationI. Boilers.I1. Industrial Furnaces.

A. Cement Kilns.B. Light-Weight Aggregate Kilns.C. Halogen Acid Furnaces.1. Current Practices.2. Designation of HAFs as Industrial

Furnaces.D. Smelting, Melting, and Refining

Furnaces Burning Hazardous Waste toRecover Metals.

Part Three: Standards for Boilers andIndustrial Furnaces Burning HazardousWaste

I. Emission Standard for Particulate Matter.A. Basis for Final Rule.1. Alternatives Considered.2. Basis for Standard.B. Interim Status Compliance Procedures.C. Implementation.

I. Controls for Emissions of Toxic OrganicCompounds.

A. DRE Standard.1. Selection of POHCs for DRE Testing.2. Use of POHC Surrogates.3. Waiver of DRE Trail Burn for Boilers

Operating Under the Special OperatingRequirements.

B. PIC Controls.1. Use of a CO Limit to Control PICs.2. Tier I PIC Controls: 100 ppmv CO limit.3. Tier II PIC Controls: Limits on CO and

HC.4. Special Requirements for Furnaces.5. Special Considerations for Cement Kilns.C. Automatic Waste Feed Cutoff

Requirements.D. CEM Requirements for PIC Controls.E. Control of Dioxin and Furnace

Emissions.11. Risk Assessment Procedures.

A. Health Effects Data.1. Carcinogens.2. Noncarcinogens.B. Air Dispersion Modeling.1. Option for Site-Specific Modeling.2. Terrain-Adjusted Effective Stack Height.3. Conservatism in Screening Limits.4. GEP Stack Height.5. Plume Rise Table.6. Compliance by Manipulating Effective

Stack Height.7. Effect of HCI Emissions on Acid Rain.8. Building Wake Effects.C. Consideration of Indirect Exposure and

Environmental Impacts.1. Indirect Exposure.2. Non-human Health Related

Environmental Impacts.D. Acceptable Risk Level for Carcinogens.E. Use of MEI and Consideration of

Aggregate Risk.F. Risk Assessment Assumptions.

IV. Controls for Emissions of Toxic Metals.A. Background Information.1. Metals Standards under Other Statutes.2. 1987 Proposed Rule.3. 1989 Supplement to Proposed Rule.B. How the Standards Work.1. Tier Ill Standards.2. Tier II Standards.3. Tier I Standards.C. Implementation.

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Federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

1. Tier I Implementation.2. Tier II Implementation.3. Tier III Implementation.4. Special Requirements for Furnaces that

Recycle Collected Particulate Matter.5. Trial Bums.6. Monitoring and Analysis Requirements.D. Interim Status Compliance

Requirements.V. Controls for Emissions of Hydrogen

Chloride and Chlorine Gas.A. Background Information.B. Response to Comments.1. Short-Term HCI RAG2.2. Need for C12 Controls.3. HCI Emission Test Procedures.4. Technology-Based HCl Controls.C. Implementation.1. Emissions Testing.2. Waste Analysis.3. Interim Status Compliance

Requirements.VI. Nontechnical Requirements.VII. Interim Status Standards.

A. Certification Schedule.1. Certification of Precompliance.2. Certification of Compliance.3. Recertification.4. Failure to Comply with the Certification

Schedule.5. Development of the Certification

Schedule.B. Limits on Operating Parameters.C. Automatic Waste Feed Cutoff.D. Sham Recycling Policy.E. Submittal of Part B Applications.F. DRE Testing.G. Chlorinated Dioxins and Furans.H. Special Requirements for Furnaces.I. Special Metals Controls for Furnaces that

Recycle Collected Particulate Matter.1. Recordkeeping.

VIII. Implementation of Today's Rule.A. Newly Regulated Facilities.1. Definition of "In Existence".2. Section 3010 Notification.3. Part A Permit Application.B. Interim Status Facilities.C. Permitted facilities.1. Amendment to § 270.42(g).2. Procedures to Modify Permits.D. Addition of Storage Units at Direct

Transfer Facilities That Obtain InterimStatus.

1. Unauthorized States.2. Authorized States.E. Compliance with BIF versus Incinerator

Rules.IX. Permit Procedures.

A. Part B Information.B. Special Forms of Permits.1. Permits for New Boilers and Industrial

Furnaces.2. Permit Procedures for Interim Status

Facilities.X. Exemption of Small Quantity Burners.

A. Response to Comments.B. Basis for Today's Rule.1. Composition of Hazardous Waste

Stream.2. Toxicity of Hazardous Constituents.3. Destruction Efficiency.4. Assumptions Regarding Metals and

Chlorine in Waste Fuels.C. How the Exemption is Implemented.1. Use of Terrain-Adjusted Effective Stack

Height.

2. Multiple Stacks.D. Wastes Ineligible for Exemption.E. Exemption of Associated Storage.F. Notification and Recordkeeping

Requirements.XI. Exemption of Low Risk Waste from DRE

Standard and Particulate MatterEmissions Standard.

A. Exemption from Compliance with theDRE Standard.

B. Exemption from Compliance with theParticulate Standard.

C. Eligibility Requirements.D. How the Low-Risk Waste Exemption

Works.1. Constituents of Concern.2. Estimation of Worst-Case Emissions.3. Dispersion Modeling.4. Acceptable Ambient Levels.5. Constituents with Inadequate Health

Effects Data.XII. Storage Standards.

A. Permit Standards for Storage.B. Consideration of Requirement for Liquid

Waste Fuel Blending Tanks.C. Standards for Direct Transfer

Operations.1. General Operating Requirements.2. Inspections and Recordkeeping.3. Equipment Integrity.4. Containment and Detection of Releases.5. Response to Leaks or Spills.6. Design and Installation of New

Equipment.7. Closure.

XIII. Applicability of the Bevill Exclusion toCombustion Residues When BurningHazardous Waste.

A. Basis for Applying the Bevill Exclusionto Derived-From Residues.

B. Evolution of Interpretations.C. Case-by-Case Determinations.1. Eligible Devices.2. Two-Part Test.D. Recordkeeping.E. Other Considerations.1. Generic Determinations.2. Burning for Destruction.

Part Four: Miscellaneous ProvisionsI. Regulation of Carbon Regeneration Units.

A. Basis for Regulating CarbonRegenerating Units as ThermalTreatment Units.

B. Definition of Carbon Regeneration Unitand Revised Definition of Incinerator.

C. Units in Existence on the Effective Dateare Eligible for Interim Status.

I. Regulation of Sludge Dryers.A. July 1990 Proposal.B. Summary of Public Comments.

III. Classification of Coke and By-ProductCoal Tar.

A. AISI Petition.B. Process Description.C. Basis for Approval of the AISI Petition.

IV. Regulation of Landfill Gas.V. Definitions of Infrared and Plasma Arc

Incinerators.Part Five: Administrative, Economic, and

Environmental Impacts, and List ofSubjects

I. State Authority.A. Applicability of Rules in Authorized

States.B. Effect on State Authorizations.

11. Regulatory Impacts.

A. Cost Analysis.1. Background.2. Revised Cost Analysis.B. Regulatory Flexibility Act.C. Paperwork Reduction Act.

Ill. List of Subjects.Appendices.

Part One: Background

I. Legal Authority

These regulations are promulgatedunder authority of sections 1006, 2002,3001 through 3007, 3010, and 7004 of theSolid Waste Disposal Act of 1970, asamended by the Resource Conservationand Recovery Act of 1976, the QuietCommunities Act of 1978, the SolidWaste Disposal Act Amendments of1980, and the Hazardous and SolidWaste Amendments of 1984, 42 U.S.C.6905, 6912, 6921 through 6927, 6930, and6974.

II. Overview of the Final Rule

A. Controls for Emissions of OrganicCompounds

. Today's rule requires boilers andindustrial furnances to comply with thesame destruction and removal efficiency(DRE) standard currently applicable tohazardous waste incinerators: 99.9999%DRE of dioxin-listed waste, and 99.99%DRE for all other hazardous wastes. Inaddition, the rule controls emissions ofproducts of incomplete combustion(PICs) by limiting flue gasconcentrations of carbon monoxide(CO), and where applicable,hydrocarbons (HC) to ensure that thedevice is operated under goodcombustion conditions. Finally,emissions testing and health-riskassessment is required for chlorinateddioxins and furans for facilities meetingspecified criteria where the potential forsignificant concentrations may exist.

B. Controls for Emissions of ToxicMetals

The rules establish emission limits for10 toxic metals listed in appendix VIII of40 CFR part 261 based on projectedinhalation health risks to a hypotheticalmaximum exposed individual (MEI). Thestandards for the carcinogenic metals(arsenic, beryllium, cadmium, andchromium) limit the increased lifetimecancer risk to the MEI to a maximum of1 in 100,000. The risk from the fourcarcinogens must be summed to ensurethat the combined risk is no greater thanI in 100,000. The standards for thenoncarcinogenic metals (antimony,barium, lead, mercury, silver, andthallium) are based on Reference Doses(RfDs) below which adverse healtheffects have not been observed.

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The standards are implementedthrough a three-tiered approach.Compliance with any tier is acceptable.The tiers are structed to allow higheremission rates (and feed rates) as theowner or operator elects to conductmore site-specific testing and analyses(e.g., emissions testing, dispersionmodeling). Thus, the feed rate limitsunder each of the tiers are derivedbased on different levels of site-specificinformation related to facility designand surrounding terrain. Under Tier I,the Agency has provided veryconservative waste feed rate limits in"reference" tables as a function ofeffective stack height and terrain andland use in the vicinity of the stack andassumed reasonable, worst-casedispersion. The owner or operatordemonstrates compliance by wasteanalysis, not emissions testing ordispersion modeling. Consequently, theTier I feed rate limits are based on anassumed reasonable, worst-casedispersion scenario, and an assumptionthat all metals fed to the device areemitted (i.e., no partitioning to bottomash or product, and no removal by an airpollution control system (APCS)).

Under Tier IL the owner or operatorconducts emissions testing (but notdispersion modeling) to get credit forpartitioning to bottom ash or product,and APCS removal efficiency. Thus, theAgency has developed conservativeemission rate limits in reference tables,again as a function of effective stackheight and terrain and land use in thevicinity of the stack. The Agency alsoassumed reasonable, worst-casedispersion under Tier II.

Under Tier III, the owner or operatorwould conduct emissions testing andsite-specific dispersion modeling todemonstrate that the actual (measured)emissions do not exceed acceptablelevels considering actual (predicted)dispersion.

The standards are implementedthrough limits on specified operatingparameters, including hazardous wastefeed rate and metals composition, feedrate of metals from all feed streams,combustion chamber temperature, andAPCS-specific parameters.

C. Controls for Emissions of HydrogenChloride and Chlorine Gas

The rules control emissions ofhydrogen chloride (HCI) and freechlorine (C12) under the same generalapproach as that used for metals. Theowner and operator must comply withand implement the HCI and C12 controlsin the same manner as for metals.

D. Emission Standards for ParticulateMatter

The rules limit particulate matter (PM)emissions of 0.08 gr/dscf, corrected to 7percent oxygen (02). This is the samestandard that currently applies tohazardous waste incinerators and isintended to supplement the risk-basedmetals controls. (Metals emissions aregenerally controlled by limiting feedrates of metals and controlling PM.)Compliance with the standard isdemonstrated by emissions testing, andthe standard is implemented byoperating limits in the permit onparameters including: ash content offeed streams, feed rate of specific feedstreams, and air pollution controlsystem operating parameters. All boilersand industrial furnaces must complywith the standard; however, cement andaggregate kilns need not monitor the ashfeed rate of all feed streams todemonstrate compliance with thestandard given that particulate matterfrom these devices is generatedprimarily from raw materials. Instead,the rule provides that these devicesmust comply with the operating limitson the particulate matter control systemto ensure continued operation at levelsachieved during the compliance test(under interim status) or trial burn(under the part B permit application).

E. Permitting Procedures

Tlie final rule requires similarpermitting procedures for regulated BIFethat apply to hazardous wasteincinerators. For example, owners andoperators are required to submit a part Bpermit application for evaluation inorder to be eligible for an operatingpermit. Permit applications will becalled on a schedule considering therelative hazard to human health andenviroment the facility poses comparedto other storage, treatment, and disposalfacilities within the Director's purview.

F. Control During Interim Status

Today's final rule requires boilers andindustrial furnaces that have interimstatus to comply with substantiveemissions controls for metals, HCL, C12,particulates, and CO (and, whereapplicable, HC and dioxins and furans).Owners and operators must certifycompliance with the emissions controlsunder a prescribed schedule, establishlimits on prescribed operatingparameters, and operate within thoselimits throughout interim status.

G. Units Exempt from Air EmissionsStandards

The rule conditionally exempts fromregulation the following devices: (1)

Boilers and industrial furnaces that burnsmall quantities of hazardous waste fuel(i.e., the small quantity burnerexemption), and that operate the device.under prescribed conditions; (2)smelting, melting, and refining furnacesthat prodess hazardous waste solely forthe purpose of metal reclamation andnot partially for destruction or energyrecovery, and (3) coke ovens if the onlyhazardous waste they process is K087.

The small quantity burnerexemption-as provided in section3004(q)(2)(B)-is a risk-based exemptionspecifically alluded to in the statute. Theexemption is provided only tohazardous waste fuels generated on-site,and is conditioned on a number ofrequirements, including a one-timenotification and recordkeeping.

The Agency Is also providing atemporary exemption for metalreclamation furnaces from today'sburner standards until we determinehow best to apply rules designed forcombusion process to noncombusionmetal reclamation operations. (It shouldbe noted that section 3004(q) requiresEPA to issue rules controlling airemissions from devices burninghazardous waste for energy recovery bya specified date. Section 3004(q) doesnot apply to devices burning hazardouswaste for the sole purpose of materialrecovery. Although EPA has authority toissue such regulations, the section3004(q) deadline does not apply). Todistinguish between waste that areprocessed solely for metal reclamationrather than (partial) destruction, thefinal rule considersd a hazardous wasteprocessed by a smelting, melting, orrefining furnace with a totalconcentration of appendix VIII, part 261toxic organic constituents exceeding 500ppm to be burned at least partially fortreatment or destruction. To distinguishbetween processing for materialrecovery and burning for energyrecovery, the final rule considers ahazardous waste processed by a metalreclamation furnace with a heatingvalue exceeding 5,000 Btu/lb to beburned at least partially for energyrecovery. Metals reclamation furnacesclaiming the exemption must notify theAgency, sample and analyze theirhazardbus wastes to documentcompliance with the conditions of theexemption,. and keep records of suchdocumentation.

Coke ovens are exempt from today'srule if the only hazardous waste theyprocess is K087 as an ingredient toproduce coke. Given that K087 is forpractical purposes just like othermaterials used to produce coke andcomes from the same process as these




other materials, it would be anomalousto assert RCRA control over the cokingprocess.

H. Pollution Prevention Impacts

This rule provides an incentive toreduce the generation of metal andchlorine-bearing hazardous waste at thesource given that the metals and HClemissions controls will be implementedby additional requirements attendant tothe disposal of those wastes, i.e., feedrate limits for individual metals andtotal chlorine. These requirements are,in essence, tied to the economics ofdisposing of given volumes of wastesince feed rates depend, in part, on thevolume of waste the facility operatorneeds to burn. Thus, the metals and HClcontrols do not simply require a percentreduction in emissions, irrespective ofthe volume and rate of incoming wastestreams. Rather, the controls are health-based and, thus, provide limits onemissions rates of metals and HC1 thatwould be implemented by feed ratelimits.

Waste generators who send theirwaste to industrial furnaces such ascement kilns and light-weight aggregatekilns that act as commercial wastemanagement facilities will have theincentive to reduce the generation ofmetal and chlorine-bearing wastesbecause waste management fees arelikely to increase for such waste giventhat the burner has a fixed metal andchlorine feed rate allotment (due toprescribed feed rates and facilityoperating conditions). Wastes withextremely high metals content may nolonger be acceptable for burning inmany cases unless the waste generatorreduces the metals content of the waste.Any alternative for the disposal of suchwastes may be unavailable or the costsof such treatment may be high enough tocreate the incentive to reduce wastegeneration rates at the source. This is atypical scenario for pollution preventionmeasures to be undertaken by wastegenerators.

Similarly, generators who burn theirwastes on site also have the incentive toreduce the generation of metal andchlorine-bearing wastes given that therule will provide a fixed feed rateallotment for their boiler or industrialfurnace.

III. Relationship to Other Rules

A. Regulations to be Promulgated Underthe New Clean Air Act

Title III of the recent Clean Air ActAmendments of 1990, amending section112 of the Act dealing with hazardousair pollutants, potentially addressesmany of the same sources that would be

regulated under today's rule. Thatsection requires the Agency to develop alist of major and area sources ofhazardous air pollutants (a major sourceis a stationary source that has thepotential to emit up to 10 tons per yearof a hazardous air pollutant, or 25 tonsper year of a combination of suchpollutants, and area sources are otherstationary sources emitting hazardousair pollutants), and to developtechnology-based controls for suchsources over specified time periods. SeeClean Air Act, amended sections 112(c),and (d). Additional controls shall beimposed within eight years afterpromulgation of each of thesetechnology-based standards, if suchcontrols are needed to protect publichealth with an ample margin of safety,or to prevent adverse environmentaleffect. (Cost, energy, and other relevantfactors must be considered indetermining whether regulation isappropriate in the case of environmentaleffects.) In addition, if the technology-based standards for carcinogens do notreduce the lifetime excess cancer riskfor the most exposed individual to lessthan one a million (10-6), then EPA mustpromulgate health-based standards. Seeamended section 112(f)(2)(A).

It is premature for the Agency toattempt to provide a definitive opinionon the relationship of these provisions totoday's rule. Sources covered by thepresent rule may not ultimately berequired to be further regulated underamended section 112. In this regard,amended section 112(n)(7) provides thatif sources' air emissions are regulatedunder subtitle C, "the Administratorshall take into account any regulationsof such emissions * * * and shall, to themaximum extent practicable andconsistent with the provisions of thissection, ensure that the requirements ofsuch subtitle and this section areconsistent." Thus, at a minimum,Congress was concerned about thepotential for duplicative regulation andurged the Agency to guard against it.Since the Agency regards today's rulesas protective (based on presentknowledge), it may be possible to avoidfurther air emissions regulation. (EPAnotes, however, that these sources willlikely be listed as major sources, and theAgency will study whether furtheremissions controls are required in thecourse of implementing amended section112.)

B. April 27, 1990 Proposed IncineratorAmendments

On April 27, 1990 (55 FR 17862), EPAproposed amendments to the existinghazardous waste incinerator standardsof subpart 0, part 264 to make the

incinerator standards conform to theemissions standards being promulgatedtoday for boilers and industrial furnacesburning hazardous waste. The proposedrule would add emission standards forproducts of incomplete combustion (i.e.,carbon monoxide and hydrocarbonlimits), metals, and hydrogen chlorideand chlorine gas.

In the proposed rule for incinerators,EPA also proposed to revise or to adddefinitions for a number of thermaltreatment devices: Industrial furnace,incinerator, plasma arc and infraredincinerators. Those definitions are beingpromulgated in today's rule. In addition,EPA proposed in the incineratorrulemaking to clarify the regulatorystatus of carbon regeneration units.Those clarifications are alsopromulgated in today's final rule.

Finally, EPA proposed to revise thedefinition of principal organic hazardousconstituents (POHCs) used todemonstrate destruction and removalefficiency (DRE). The revised definitionwould allow the Director on a case-by-case basis to approve as POHCscompounds that are neither constituentsin the hazardous waste nor organic.That revised definition of POHC isfinalized in today's rule as a part of theDRE standard to control organicemissions from boilers and industrialfurnaces.

C. July 18, 1990 Proposed Amendment toDefinition of Wastewater TreatmentUnit to Exempt Sludge Dryers

On July 18, 1990 (see 55 FR 29280),EPA proposed to clarify the regulatorystatus of sludge dryers to make it clearthat sludge dryers that meet thedefinition of a tank and that were a partof a wastewater treatment unit wereexempt from RCRA regulation even ifthey heretofore met the definition of anincinerator. Today's final rulepromulgates a definition of sludge dryerand revises the definition of incineratorto explicitly exclude sludge dryers. SeePart Four, section II of today's preamble.

D. Land Disposal Restriction Standards

In the May 6, 1987 proposal, theAgency indicated that once the presentrules became final, the Agency wouldamend certain of the land disposalrestriction standards that specifiedincineration as a treatment standard (atthat time, the standard for HOCs underthe California list rule), to also includeburning in boilers and industrialfurnaces. See 52 FR at 17021. Since thattime, the issue has become moreinvolved. In particular, significant issuesregarding the relationship of the Bevillamendment and land disposal

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restrictions exist (which the Agency infact referenced in the rulemaking recordto the California list rule whenconsidering this issue). The Agencybelieves it inappropriate to try andresolve these issues in this proceeding,given the time constraints created by theDistrict Court's order and the fact thatthis rulemaking does not dealprincipally with issues relating to theland disposal restrictions program. TheAgency consequently plans to addressthese questions in a later proceedingand not to finalize the May 1987proposal at this time.Part Two: Devices $ubject to Regulation

I. BoilersEPA defines a boiler in § 260.10 as an

enclosed device using controlled flamecombustion and having the followingcharacteristics: (1) The combustionchamber and primary energy recoverysection must be of integral design; (2)thermal recovery efficiency must be atleast 60 percent; and (3) at least 75percent of the recovered energy must be"exported" (i.e., not used for internaluses such as preheating of combustionair or fuel, or driving combustion airfans or feed water pumps).

Today's final rule applies to all boilersburning hazardous waste for anypurpose-energy recovery ordestruction. (We note, however, that anexisting boiler may not burn hazardouswaste for destruction (i.e., waste that isnot a fuel) before certifying compliancewith the interim status emissionsstandards.)

Nonindustrial boilers are currentlyprohibited from burning hazardouswaste unless they are operated inconformance with the incineratorstandards of subpart 0 of part 264 or265. On the effective date of today'srule, however, nonindustrial boilersburning hazardous waste will be subjectto these boiler and industrial furnacerules. We note that nonindustrial boilersgenerally cannot burn hazardous wasteuntil they receive an operating permitunder today's rule (unless they arealready operating under the incineratorstandards). This is because theprohibition is not rescinded until theeffective date of the rule, and a facilitywould have to be "in existence" withrespect to hazardous waste burning onthat date to be eligible for interim status.

EPA believes that approximately 925boilers burn hazardous waste fuels.Approximately 600 of these boilers burnvery small quantities of hazardouswaste and will be conditionally exemptunder the small quantity burnerprovision of today's rule. See § 266.108.(We note that these boilers burn less

than one percent of the total hazardouswaste currently being burned In boilersand industrial furnaces.) EPA alsobelieves that approximately 200 boilerswill stop burning hazardous wastebecause they burn quantities exceedingthe small quantity burner exemption butdo not burn enough waste to justify thecost of complying with today's rule.Thus, approximately 125 boilers willcontinue to burn hazardous waste andwill be subject to the interim status andpermit standards provided by § § 266.102and 266.103 of today's rule.

H. Industrial FurnacesUnder today's revised definition, EPA

defines an industrial furnace in § 260.10as those designated devices that are anintegral component of a manufacturingprocess and that use thermal treatmentto recover materials or energy. With theaddition of halogen acid furnaces bytoday's rule, the Agency has designated12 devices as industrial furnaces:Cement kilns; lime kilns; aggregate kilns(including light-weight aggregate kilnsand aggregate drying kilns used in theasphaltic concrete industry); phosphatekilns; coke ovens; blast furnaces;smelting, melting, and refining furnaces;titanium dioxide chloride processoxidation reactors; methane reformingfurnaces; pulping liquor recoveryfurnaces; and combustion devices usedin the recovery of sulfur values fromspent sulfuric acid. The definition alsoincludes criteria and procedures fordesignating additional devices asindustrial furnaces.

Any industrial furnace burning orprocessing any hazardous waste for anypurpose--energy recovery, materialrecovery, or destruction-is subject totoday's rule, with certain exceptions.Furnaces (like boilers) burning smallquantities of hazardous waste fuel areexempt from regulation under § 266.108,coke ovens are exempt from regulationif the only hazardous waste they burn isHazardous Waste No. K087, andregulation of smelters processinghazardous waste solely for materialrecovery is deferred (see discussion insection II.D).

The Agency believes thatapproximately 75 industrial furnacesburn over one million tons of hazardouswaste annually. The regulated universeappears to comprise approximately 40cement kilns, 18 light-weight aggregatekilns, and 15 halogen acid furnaces.Each of these types of furnaces isdescribed below.

A. Cement KilnsCement kilns are horizontal inclined

rotating cylinders, refractory lined andinternally fired, to calcine a blend of

80% limestone and 20% shale to producePortland cement. There is a wet processand a dry process for producing cement.In the wet process, the limestone andshale are ground wet and fed into thekiln in a slurry. In the dry process, rawmaterials are ground dry. Wet processkilns are longer than dry process kilns inorder to facilitate water evaporationfrom the wet raw material. Wet kilnscan be more than 450 feet in length. Drykilns are more thermally efficient andfrequently use preheaters orprecalciners to begin the calciningprocess before the raw material is fedinto the kiln.

Combustion gases and raw materialsmove counterflow in kilns. The kiln isinclined, and raw materials are fed intothe upper end while fuels are normallyfed into the lower end. Combustiongases thus move up the kiln counter tothe flow of raw materials. The rawmaterials get progressively hotter asthey travel the length of the kiln. Theraw materials eventually begin to softenand fuse at temperatures between 2,250and 2,700 'F to form the clinker product.Clinker is then cooled, ground, andmixed with other materials such asgypsum to form Portland cement.

Combustion gases leaving the kilntypically contain from 6 to 30% of thefeed solids as dust. Particulateemissions are typically controlled withelectrostatic precipitators or fabricfilters (baghouses), and are oftenrecycled to the kiln feed system.

Dry kilns with a preheater orprecalciner often use a by-pass duct toremove from 5 to 30% of the kiln off-gases from the main duct. The by-passgas is passed through a separate airpollution control system to removeparticulate matter. By-pass dust is iotreintroduced into the kiln system toavoid a build-up of metal salts that canaffect product quality.

Some cement kilns burn hazardouswaste fuels to replace from 25 to 75% ofnormal fossil fuels. Most kilns burnliquid waste fuels but several burn small(e.g., six gallon) containers of viscous orsolid hazardous waste fuels. Containershave been fired into the upper, rawmaterial end of the kiln and at themidpoint of the kiln.

Several cement companies have alsoexpressed an interest in using solidhazardous waste such as contaminatedsoils as an ingredient to producecement. Cement kilns that burnhazardous waste as an ingredient areregulated by today's rule.1 Under

ISee discussion in se ction Vl.H of Part Three ofthe text.




today's rule, a facility may burn (orprocess) hazardous waste solely as abona fide ingredient during interimstatus beginning with the effective dateof the rule. If a waste is burned partiallyfor destruction or energy recovery,however, it is not burned solely as aningredient and special restrictions applyduring interim status (see discussionbelow). EPA considers a waste to beburned at least partially for destructionif it contains a total of 500 ppm or moreby weight of nonmetal hazardousconstituents listed in appendix VIII, part261. Further, EPA considers a waste tobe burned at least partially for energyrecovery if it has a heating value of 5,000Btu/lb or more.

Today's rule does not allow burning ofa waste for the purpose of destructionduring interim status prior tocertification of compliance (see§ 266.103(c)) with all applicableemission standards. Further, the ruleapplies special requirements duringinterim status on owners/operators whofeed hazardous waste into a kiln systemat any location other than the "hot" endwhere product is discharged. Hazardouswaste burned (processed) solely as aningredient, however, is not subject to thespecial requirements because emissionsfrom such burning would not pose anadverse effect on human health and theenvironment.2

B. Light-Weight Aggregate Kilns

Light-weight aggregate (LWA)describes a special use aggregate with aspecific gravity much less than sand andgravel which is used to produceinsulation and nonstructural and light-weight concrete. LWA is produced muchlike cement, but the feedstocks arespecial clays, pumice, scoria, shale, orslate.

The LWA kiln is configured much likea cement kiln. The raw material iscrushed and introduced at the upper endof a rotary kiln. In passing through thekiln, the materials reach temperatures of1,900 to 2,10 0°F. Heat is provided by aburner at the lower end of the kilnwhere clinker is discharged.

LWA kilns are also major sources ofparticulate emissions and are equippedwith wet scrubbers, fabric filters, orelectrosatic precipitators. Wet scrubbersdominated the industry until recently.Many facilities are now converting todry systems to reduce the cost of residue

This is because nonmetal toxic constituents willnot be present in the waste at significant levels (i.e.,less than 500 ppm) and metal emissions will beadequately controlled under today's rule by the airpollution control system irrespective of where thewaste is fed into the kiln system.

management by recycling the collecteddust into the kiln.

LWA kilns that burn hazardous wastefuel typically burn 100% liquidhazardous waste fuels.

C. Halogen Acid Furnaces

The Dow Chemical Company (DOW)filed a rulemaking petition with EPA onMarch 31, 1986, in accordance with theprovisions of 40 CFR 260.20, requestingthat EPA designate their halogen acidfurnaces (-AFs) as industrial furnaces.HAFs are typically modified firetubeboilers that process secondary wastestreams containing 20 to 70 percentchlorine or bromine to produce ahalogen acid product by scrubbing acidfrom the combustion gases. CurrentlyHAFs that produce steam meet thedefinition of a boiler while HAFs that donot generate steam meet the definitionof an incinerator even though they usehazardous waste as a fuel and as aningredient to produce halogen acidproduct. Today's rule designates HAFsthat do not generate steam as anindustrial furnace for the reasons givenbelow.

DOW petitioned the Agency todesignate their HAFs as industrialfurnaces after the Agency changed thedefinition of incinerator in 1985 from a"purpose of burning test" to a "designtest" and developed new classificationsfor boilers and industrial furnaces. TheAgency inadvertently did not designateHAFs as industrial furnaces at the timewhich potentially left certain HAFsoperating not in compliance with theincinerator standards promulgated in1981. Although HAFs (prior to today'srule) technically meet the definition ofincinerator, the Agency has indicated itsintention since receiving the DOWpetition to correct the problem and toproperly designate IIAFs as industrialfurnaces.

On May 6, 1987 (52 FR 17033), EPAproposed to grant this petition and toadd halogen acid furnaces (HAFs) to thelist of devices that are designated asindustrial furnaces under 40 CFR 260.10.On April 27, 1990 (55 FR 17917), theAgency proposed changes to theproposed designation of HAFs asindustrial furnaces. With modificationsbased on additional information andcomments, today's rule adds HAFs tothe list of devices that are included inthe definition of an industrial furnaceunder 260.10.

In today's rule, EPA is defining an"industrial furnace" in 260.10 as anenclosed device that uses thermaltreatment to recover (or produce)materials or energy as an integral

component of a manufacturing process.8

EPA has previously designated 11devices as industrial furnaces: (1)Cement kilns; (2) lime kilns; (3)aggregate kilns (including light-weightaggregate kilns and aggregate dryingkilns used in the asphaltic concreteindustry); (4) phosphate kilns; (5) cokeovens; (6) blast furnaces; (7) smelting,melting, and refining furnaces; (8)titanium dioxide chloride processoxidation reactors; (9) methanereforming furnaces; (10) pulping liquorrecovery furnaces; and (11) combustiondevices used to recover sulfur valuesfrom spent sulfuric acid.

The industrial furnace definition in260.10 also provides criteria andprocedures for adding devices to the list.A device may be defined as anindustrial furnace if it meets one or moreof the following criteria: (1) The deviceis designed and used primarily torecover material products; (2) the deviceis used to burn or reduce raw materialsto make material products; (3) the deviceis used to burn or reduce secondarymaterials as effective substitutes for rawmaterials in processes that use rawmaterials as principal feedstocks; or (4)the device is used to burn or reducesecondary materials as ingredients inindustrial processes to manufacturematerial products.

As explained below, the basis fordesignating HAFs as industrial furnacesunder § 260.10 is that HAFs are integralcomponents of a manufacturing process,they recover materials and energy, andthey meet two of the criteria (1 and 4)described above for classifying a deviceas an industrial furnace.

1. Current Practices

Information available to EPAindicates that at least 3 companies inthe United States operate at least 30devices that may be halogen acidfurnaces. These devices typicallyprocess chlorinated or brominatedsecondary materials with 20 to 70percent halogen content (by weight) toproduce an acid product, eitherhydrogen chloride (HCI) or hydrogenbromide (HBr), both of which have ahalogen content that ranges from 3 to

8 This definition of industrial furnace is therevised definition as noticed on April 27, 1990 f55 FR17869). The previous definition read "an encloseddevice using controlled flame combustion to recovermate'ials or energy as an integral component of amanufacturing process." Public comments on theproposal are discussed in the Comment ResponseDocument for the BIF Regulations. EPA revised thedefinition to include nonflame devices (i.e., byreferring to thermal treatment) because controlled-flame devices and nonflame devices can have thesame emissions and pose the same hazard to humanhealth and the environment.

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greater than 25 percent (by weight].These secondary materials typicallyhave as-fired heating values ofapproximately 9,000 Btu/lb and aretypically produced on site.

Some of the HAFs currently in use aremodified firetube boilers that generateand export steam. These HAFs meet thedefinition of a boiler under § 260.10, and,thus, will be regulated as boilers. Theremaining HAFs, although modifiedfiretube boilers, do not generate steamand thus do not meet EPA's definition ofa boiler. Today's rule classifies thesenonboiler HAFs as industrial furnaces.For the remainder of this discussion, theterm "HAF" refers to these nonboilerHAFs.2. Designation of HAFs as IndustrialFurnaces

a. Dow's Petition. On March 31, 1986,the Dow Chemical Company (DOW)filed a rulemaking petition with EPA inaccordance with the provisions of 40CFR 260.20, requesting that HAFs atDow Chemical be designated asindustrial furnaces. EPA proposed togrant this petition in the May 6, 1987proposal. Today's rule includes HAFs inthe definition of an industrial furnaceunder § 260.10. Further backgrounddiscussion on DOW's petition iscontained in the May 6, 1987 proposedrule.

b. May 1987 and April 1990 ProposedRules. EPA proposed to designate HAFsas industrial furnaces for the reasonsdiscussed in the May 6, 1987 proposedrule. To ensure that a particular devicewas an industrial furnace involved inbona fide production of acid 4 as anintegral component of a manufacturingprocess, and was not an incineratorequipped with hologen emissionsremoval devices, the 1987 proposed HAFdefinition required that: (1) The furnaceby located on site at a chemicalproduction facility; (2) the waste fed tothe device be halogenated; and (3) theacid product from the device contain atleast 6 percent halogen acid.

Based on comments received on the1987 proposal and on furtherconsideration by the Agency, EPAproposed revisions to the HAF definitionin the April 1990 notice. These revisionswere proposed for two reasons: (1) To

4 The Agency's concern is that devices capturingsome HCI in scrubber effluent not automatically beclassified as HAFs if they find a way to utilize thescrubber effluent. The HCI content of the effluentfrom wet scrubbers used to control HCI emissionsfrom the incineration of chlorine-bearing waste isnormally on the order of 1 percent of less. EPA doesnot consider such low HCI content scrubber water abona fide product for purposes of designation as anindustrial furnace even if the scrubber water isbeneficially used in a manner that specificallyrelates to its HCI content.

better clarify the differences betweenHAFs and incinerators equipped withwet scrubbers to control halogen acidemissions, and (2) to better reflectindustry practice.

To ensure that a particular device isan integral component of a chemicalmanufacturing process, the April 1990proposal included requirements that atleast 50 percent of the acid product beused on site and that any off-site wastefed to the HAF be generated by a SIC281 (inorganic chemicals) or SIC 286(organic chemicals) process. To ensurethat the waste is burned as a bonafideingredient to produce the halogen acidproduct, the April 1990 proposal alsorequired that each waste fed to the HAFhave an "as-generated" halogen contentof at least 20 percent. In addition, tobetter reflect industry practice, the 1990proposal required that the acid producthave a halogen acid content of 3 percentrather than 6 percent, an amount thatstill clearly distinguished the HAF acidproduct from incinerator scrubber water,which has an acid content of well belowI percent. Finally, EPA proposed inApril 1990 to list hazardous waste fed toa HAF as inherently waste-like toensure that halogenated waste fed to aHAF (and the HAF itself) would besubject to regulation. This wouldpreclude a claim that the secondarymaterials were used as ingredients tomake a product, and, thus, not a solidwaste under § 261.2(e(1)(i).

c. Summary of Public Comments.Commenters on the 1987 and 1990proposed rules objected to therequirements that 50 percent of the acidproduct be used on site and that any off-site waste feed be limited to SIC 281 or286 processes. The commenters arguedthat minimum specifications on thehalogen content of the feed and/or theacid content of the HAF product aresufficient to distinguish bona fide HAFoperations from incinerator operations,and that the requirement that asubstantial portion of the product beused on site serves only to limit thelegitimate treatment of halogenatedwastes and the sale of bona fide HAFproducts without being necessary toprotect human health and theenvironment.

After consideration of thesecommenters' concerns, the Agencybelieves that both the proposed off-siterestriction for waste fed to HAFs andthe proposed on-site acid product userestriction are indeed unnecessary toensure that HAFs are integralcomponents of manufacturing processes.The Agency agrees with the commentersthat the requirements specifying theminimum halogen content of the waste

feed and the minimum halogen acidconcentration of the HAF product aresufficient to ensure that HAFs areintegral components of a manufacturingprocess (i.e., the process of halogen acidproduction). EPA is not adopting theseproposed conditions given that airemissions from HAFs will be regulatedunder today's rule, that these proposedconditions were directed at how toclassify these devices rather than howto ensure their safe operation, and thatHAF operations (as properly controlled)are environmentally advantageous inthat they utilize acid values rather thandispose them and therefore should notneedlessly be discouraged. Today's rule,therefore, does not restrict the use ofHAF waste feeds generated off site orrequire that any percentage of the acidproduct be used on site.

In today's rule, the Agency considersa bona fide HAF operation as one inwhich a secondary material with aminimum as-generated halogen contentof 20 percent by weight is processed intoan acid product with a minimumhalogen content of 3 percent by weight.The acid product must be used in amanufacturing process either on site oroff site. The Agency maintains that thisapproach will allow the legitimateprocessing of highly halogenatedsecondary materials into usableproducts but will still clearly distinguishHAF product acid from incineratorhalogen acid scrubber water.

Upon review of other commentssubmitted on the 1987 and 1990proposed rules, the Agency hasidentified several issues pertaining toHAFs that require clarification in theregulations. Specifically, these issuesconcern: (1) The regulation of chlorineemissions from HAFs, (2) the operationof HAFs under the special operatingrequirements (SOR) exemption forboilers, and (3) the designation ofhazardous waste fed to HAFs asinherently waste-like material.

One commenter to the 1987 proposedrule requested that the Agency clarify itsposition on limiting inorganic halidesalts in feedstocks to boilers andindustrial furnaces. The Agency hasestablished limits on emissions of HCIand C12 from industrial furnaces, and aHAF operator, like any other industrialfurnace operator, must comply withthese HCI and Cl2 emission standards.To demonstrate compliance under theTier I feed rate screening limits, a HAFoperator must include inorganic chlorineas part of the total chlorine fed to thedevice. The Agency believes that thisrequirement is justified because recenttesting indicates that even thermallystable compounds such as NaCl are




converted with high efficiency to HCunder laboratory conditions thatsimulate incineration. 5

Another commenter to the 1987proposal stated that HAFs are unjustlyexcluded from the automatic waiver of atrial burn to demonstrate 99.99%destruction and removal efficiency(DRE) when operated under the specialoperating requirements (SORs). TheAgency acknowledges the commenter'sconcern, but notes that all industrialfurnaces, including HAFs, are ineligiblefor the automatic DRE trial burn waiver.The Agency stated in the preamble tothe 1987 proposal that modified boilersthat produce and export steam (and thusmeet EPA's definition of boiler in§ 260.10) would be regulated as boilers.In such a case, the unit may be eligiblefor the automatic waiver of the DRE trialburn, which applies only to boilers. Anyhalogen acid furnace that is a modifiedfire-tube boiler not meeting thedefinition of a boiler in § 260.10,however, would not be eligible for theautomatic waiver. The Agency's reasonsfor applying the automatic DIRE trialburn waiver only to boilers arediscussed further in Section II.C.2.d ofthis preamble.

Several commenters expressedooncern that the April 27, 1990 proposalrequired a minimum heating value of5,000 Btu/lb for secondary materials fedto HAFs. Today's final rule does notrequire a minimum heating value onsecondary materials fed to HAFs.Although the Agency understands thatmost wastes burned in HAFs have aheating value greater than 5,000 Btu/lband, so, that HAFs are engaged inenergy recovery as well as materialsrecovery, not all wastes meeting theminimum halogen limit also have aheating value normally associated withenergy recovery. The Agency believesthat HAFs need not be required torecover both material and energy valuesfrom every hazardous waste fed to thedevice to meet the definition of anindustrial furnace, and that theregulations adopted today for HAFsensure that they will be operated in aprotective manner even if energy valuesare not recovered.

Commenter's misconceptionsregarding a minimum heating value forsecondary materials may have arisenfrom the Agency's proposal pursuant to§ 261.2(d)(2) to list hazardous waste fedto HAFs as inherently waste-likematerial. In today's rule, the Agency islisting as inherently waste-like anysecondary material fed to HAFs that is

5 U.S. EPA, Laboratory Method to EstimateHydrogen Chloride Emission Potential BeforeIncineration of a Waste, February 1990.

identified or listed as a hazardous wasteunder 40 CFR part 261, subparts C andD. Without such materials beingdesignated as inherently waste-like,HAFs burning hazardous wastes solelyas ingredients (i.e., wastes that have lowheating value and therefore, are notburned partially for energy recovery) toproduce an acid product might not beregulated because the material they areburning might not be a solid wastepursuant to § 261.2(e)(1)(i). However,HAFs that burn hazardous wastes withhigh heating values (i.e., greater than5,000 Btu/lb), would be subject totoday's rule even without listing them asinherently waste-like because thesewastes are considered under§ 261.2(e)(2)(ii) to be burned at leastpartially for energy recovery. Forreasons discussed in the April 27, 1990proposed rule (55 FR 17892), the Agencybelieves that such an inconsistent resultwould not provide adequate protectionof human health and the environment(the wastes burned by HAFs are someof the most toxic generated andregulation of emissions from burningthese wastes certainly is needed toprotect human health and theenvironment). Moreover, there aresignificant elements of treatmentassociated with burning in HAFs: toxicorganic compounds are destroyed ratherthan recovered, and the burning ifconducted improperly could becomepart of the waste disposal problem.Because the materials burned in HAFsmeet the criteria of § 261.2(d) forinherently waste-likely materials, EPAtoday is adding to the list of inherentlywaste-like materials under § 261.(d)(2)secondary materials fed to HAFs thatare listed or identified as hazardouswaste under subparts C or D of part 261.While HAFs will not be precluded fromburning secondary materials with lowheating values, today's listing willprevent the HAFs that burn this materialand the material itself from beingunregulated. As a result, in all cases,hazardous waste fed to HAFs, and theHAFs themselves, will be subject tohazardous waste regulations undertoday's final rule.

d. Basis for Designating HAFs asIndustrial Furnaces. EPA has defined anindustrial furnace in § 260.10 as any ofthe specifically-designated encloseddevices that are integral components ofa manufacturing process and that usethermal treatment to accomplishrecovery of materials or energy. To date,11 types of devices have beendesignated as industrial furnaces. Theindustrial furnace definition alsoprovides criteria for adding devices tothe list. As discussed above, these

criteria include: (1) The design and useof the device primarily to accomplishrecovery of material products; (2) theuse of the device to burn or reduce rawmaterials to make a material product; (3)the use of the device to burn or reducesecondary materials as effectivesubstitutes for raw materials inprocesses using raw materials asprincipal feedstocks; and (4) the use ofthe device to burn or reduce secondarymaterials as ingredients in an industrialprocess to make a material product. Asexplained below, HAFs, meet thedefinition of an industrial furnace aswell as two of the above criteria, (1) and(4), for designating additional devices asindustrial furnaces.

HAFs are Integral Components of aManufacturing Process. HAFs arecommonly located on-site at large scalechemical manufacturing processes thatreclaim primarily secondary materialsgenerated on-site and that typically usethe halogen acid product on-site. Inthese cases, the Agency believes thedevice should clearly be considered anintegral component of the manufacturingprocess and, thus, eligible fordesignation as an industrial furnace.The situation is less clear when thedevice receives halogen-bearingsecondary materials from off-site or ifthe halogen acid product is sent off-site.In these situations, the Agency believes,nonetheless, that the device should beconsidered an integral component of amanufacturing process and, thus,eligible for consideration as anindustrial furnace provided that thedevice is located on the site of amanufacturing process and that thehalogen acid product is used by amanufacturing process.

HAFs Recover Materials and Energy.EPA believes that HAFs recovermaterials and energy to produce a bonafide product. Production of halogen acid(a 3 to 20 percent halogen acid solution)from the combustion of chlorine-bearingsecondary materials constitutesmaterials recovery in the context of thedesignation of HAFs as industrialfurnaces. HAFs can also be considleredto burn secondary material asingredients in an industrial process tomake a material product (i.e., theproduct halogen acid). As discussedabove, chlorine-bearing secondarymaterials are burned to produce thehalogen acid product for use in amanufacturing operation.

HAFs also recover energy. Mosthalogen-bearing secondary materialsreclaimed in HAFs are burned partiallyfor energy recovery because substantial,usable heat energy is released by thematerials during combustion. The

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materials typically have an as-firedheating value of approximately 9,000Btu/lb, and the heat released results inthe thermal degradation of chlorinatedorganic compounds to form HCI.Although under definitions in 260.10,energy recovery in a boiler ischaracterized by the recovery andexport of energy, energy recovery in anindustrial furnace need not involve anyexport of energy. Rather, energyrecovery in an industrial furnace isbased on the burning of materials withsubstantial heating values (greater than5,000 Btu/lb) in a manner that results inthe release of substantial usable heatenergy. See 50 FR 49171-49174(November 29, 1985).6

HAFs Meet Industrial FurnaceCriteria. The Agency beleives thatHAFs meet two of the above criteria(i.e., criteria (1) and (4)) for designatingdevices as industrial furnaces. EPAbelieves that restrictions on the halogencontent of waste streams fed to HAFsand on the halogen content of the acidproduct ensure that the HAF is: (a)Designed primarily to recover halogenacid (and so is not engaged inincineration); and (b) used to burnsecondary materials as ingredients inthe process of halogen acid productionto produce a material product (i.e., theproduct halogen acid).

Addition of HAFs to List of IndustrialFurnaces. EPA believes that HAFs areintegral components of a manufacturingprocess and that they are designed andoperated to recover materials andenergy. For these reasons EPA is todayadding to the list of devices designatedas industrial furnaces under § 260.10HAFs defined as furnaces that: (1) Arelocated at the site of a manufacturingprocess; and (2) process hazardouswastes with a minimum as-generatedhalogen content of 20 percent by weightto produce an acid product with aminimum halogen content of 3 percentby weight and where the acid product isused in a manufacturing process.

e. Interim Status for HAFs. HAFs thatare in existence on the effective date oftoday's rule are eligible for interimstatus like other boilers and industrialfurnaces burning for energy or materialrecovery. Although certain HAFs maytechnically have met the amendeddefinition of incinerator, EPA believesthat there was legitimate confusion as tosuch unit's operating status. Thesedevices would not have beenincinerators under the original 1980

6 We note as discussed previously in the text that,although all hazardous wastes fed to a HAF musthave an as-generated halogen content of at least20%, all such wastes need not have a heating valueof 5.000 Btu/lb.

definition of incinerator because theirprimary purpose was not destruction ofwaste. When EPA amended thatdefinition in 1985 to adopt a definitionbased on the unit's design rather than itsoperating purpose, the Agency did notintend to regulate HAFs as incineratorsand noted that the regulatory changewas not intended to for expected to)affect the number and identity ofregulated incinerator units. See 50 FR625 (Jan. 4, 1985). Moreover, given thatmany HAFs met the definition of boiler,it would have been anomalous andunintended for some HAFs to be subjectto full regulation and others to beunregulated (until the present rules wereadopted). Given these circumstances,the Agency is finding pursuant to§ 270.10(e)(2) that there was substantialconfusion as to which HAF owners andoperators were required to submit a partA application and that this confusion isattributable to ambiguities in the subtitleC rules. Accordingly, such owners andoperators may submit part Aapplications by the effective date oftoday's regulation.

We note that this policy on interimstatus eligibility date does not apply toother devices that are currently subjectto regulation as an incinerator but claimto be an industrial furnace subject to theBIF rule and its interim status eligibilitydate. An example is an aggregate kilnthat currently burns hazardous wastefor the purpose of treatment(destruction) and, so, is subject to theincinerator standards of subpart 0,parts 264 and 265. There is no ambiguityabout the regulatory status of such adevice given that the Agency clearlyintended for such burning to be subjectto the incinerator standards, and theAgency's rules have always so stated.Thus, the date for interim statuseligibility for such facilities is the 1981date for incinerator interim status.

D. Smelting, Melting, and RefiningFurnaces Burning Hazardous Waste toRecover Metals

In the October 1989 supplement to theproposed rule, EPA solicited furthercomment on an appropriate regulatoryregime for smelting furnaces burninghazardous waste for the exclusivepurpose of material recovery. See 54 FR43733. This issue was closely connectedwith the question of jurisdictionallimitations on the Agency's authority toregulate industrial furnaces burningsecondary materials for materialrecovery, discussed under the rubric ofindigenous wastes. Id. at 43731-32. TheAgency noted generally that where itdid not perceive jurisdictionallimitations on its authority, it regardedregulation of organic emissions from

smelting furnaces as unnecessary giventhe normal absence of organics in thematerial fed to the unit. We alsoindicated concern at the prospect ofregulating emissions of metals that werenot attributable to the processing ofhazardous waste, and accordinglysolicited comment as to a means ofdetermining when burning of hazardouswaste resulted in emissions in excess ofthose from processing other materials inthe device. Id. at 43733. With respect toa test for determining when wastes areindigenous, the Agency reproposed afairly broad test that would have hadthe effect of excluding many wastes anddevices from the Agency's jurisdiction,but would have distinguished betweenwastes being burned for the purpose ofconventional treatment, and for thepurpose of material recovery treatment.

These proposals proved extremelycontroversial. Perhaps more importantly,after the proposal was issued, thequestion of indigenous waste was thepartial subject of the District ofColumbia Circuit Court of Appeals'decision API v. EPA, 906 F. 2d 726 (D.C.Cir. 1990). In that decision, the courtstated that the Agency had been overlyrestrictive in interpreting thejurisdictional limitations imposed by thestatutory definition of solid waste basedupon the court's earlier opinion inAmerican Mining Congress v. EPA, 824F. 2d 1177 (D.C. Cir. 1987). That earlieropinion, the court held, is limited tosituations involving continuousrecycling processes that are not part ofthe waste disposal problem, andcertainly does not mandate the type ofindigenous principle that the Agencydiscussed in the 1989 notice. 906 F. 2d at740-41. The court accordingly remandedand directed the Agency to rethinkwhether any type of indigenousprinciple is warranted given the court'sclarification of its earlier opinion.7 Id. at741.

The court's opinion, as well as themany comments on this issue, raisecomplex issues that EPA has not yetresolved. (In this regard, the Agencynotes that the mandate in section3004(q) to regulate facilities burninghazardous waste for energy recovery asmay be necessary to protect humanhealth and the environment does not

I Technically, the court remanded the Agency'sdecision not to formally adopt a treatment. standardunder the land disposal restrictions program for theresidue from processing a waste the Agency hadindicated would be indigenous to a particular typeof metal recovery furnace. Id, at 740. EPA has sinceindicated, in motions filed with the court, that itviews the interim treatment standard based onstabilization as applying in all cases where theresidue remains a hazardous waste.




apply to devices burning for the purposeof material recovery, H. Rep. No. 198,98th Cong., 1st Sess. 40, and so thecourt-ordered December 31, 1990issuance date does not apply.) Inparticular, the Agency is presentlystudying the question of jurisdiction aspart of a comprehensive effort todetermine if the Agency's rules onrecycling should be amended (either asa regulatory matter or as part of RCRAreauthorization). In the interim,however, the Agency does not believe itprudent to apply regulations to a wholepotential class of devices and wastesthat the Agency has not fully evaluated(since these situations would have beenexcluded from regulation under theproposal). See provision for conditionaldeferral of smelting, melting, andrefining furnaces under § 266.100(c). Inaddition, because EPA has placed mostof its efforts into issuing the mandatedportion of these regulations as soon aspossible, the Agency has not resolvedthe questions of how to regulate raisedin the 1989 notice even for the class ofsmelting furnaces where authoritywould have existed under the proposedview of indigenous waste. The issue ofwhether material recovery is a form of"treatment" is also presently submittedfor decision to a panel of the DC Circuitin Shell Oil v. EPA (No. 80-1532), andthe Agency believes it prudent to awaitthe court's ruling.

Another reason for deferringregulation of these devices is that theAgency wishes to study further whetherregulation under the Clean Air Act maybe more appropriate than RCRAregulation. Smelting, melting, andrefining furnaces have been traditionalsubjects of Clean Air Act regulation,and with the advent of amended section112 of the Clean Air Act Amendments of1990, technology-based controls on toxicair emissions are likely to apply to thesedevices. Given that in many instancesthe principal risks potentially posed byair emissions from these devices wouldcome from the nonhazardous wasteportion of feed (see 54 FR at 43733), andthat Clean Air Act regulation may resultin control of individual toxics, theAgency believes that further study of themost appropriate means of regulation iswarranted. (The Agency specificallyrequests information on other devicesthat may burn hazardous waste solelyfor metal recovery. EPA will use suchinformation to consider whether thedeferral for smelting, melting, andrefining furnaces should be broadenedprovided that the principles stated hereapply to the other devices as well.)

At the same time, EPA is concernedthat this deferral not become a license

for sham recycling activities, or foroperations motivated by conventionaltreatment objectives rather thanrecovery purposes. Accordingly, theAgency has crafted this deferralnarrowly. First, only smelting, melting,and refining furnaces (as used in the§ 260.10 definition of "industrialfurnace") burning hazardous wastesolely to recover metals would beeligible for this deferral. In the unlikelyevent that one of these devices would beused to recover organics or nonmetalinorganics, EPA believes thatsubstantial amounts of organics wouldbe destroyed showing that the purposeof the activity was either conventionaltreatment or energy recovery. (TheAgency notes specifically that it intendsto include as a smelting, melting, orrecovery furnace the types of hightemperature metal recovery devicesused as the basis for the land disposalprohibition treatment standard forwaste K061, and other similar devices.)

Second, sham recovery operationswould be viewed as conventionaltreatment operations and would requirea permit to control emissions. Althoughit is difficult to quantify whenoperations are sham, two fundamentalnotions are that any waste involvedmust contain economically viableamounts of metals to recover (the bestobjective measure would be the same orgreater levels of metal as in normalnonhazardous feed stocks), and that theperson recovering the metal be in thebusiness of producing metals for publicsale (whether to an ultimate user or forfurther processing or manufacture). Seealso 53 FR at 522 (Jan. 8, 1988). Thelimitations on Btu level and levels ontoxic organics discussed below arefurther efforts to ensure that only bonafide metal recovery activities bedeferred from emissions regulation atthis time.

Third, today's regulations are deferredonly when these devices burn (process)hazardous waste exclusively for metalrecovery and not partially fordestruction or energy recovery as well.To implement this policy, today's ruleprovides that a waste with a heatingvalue of 5,000 Btu/lb or more (either as-generated or as-fired) is burned (at leastpartially) as a fuel. The heating valuelimit is based on the Agency's longstanding sham recycling policy (48 FR11157 (March 16, 1983)) that wastes witha heating value of 5,000 Btu/lb or moreare considered to be fuels. See also 50FR at 49171-173 (Nov. 29, 1985) (partialburning for energy recovery is coveredby section 3004(q) and Btu-rich wastesare burned at least partially for thatpurpose).

Finally, only wastes that contain lessthan 500 ppm total toxic organicconstituents listed in appendix VIII, part261, will be considered to recovermetals. EPA believes that it is importantto have an objective measure todetermine when burning is for metalrecovery, and that a 500 ppm level iswithin the zone of reasonable valuesthat the Agency could select for thispurpose. As noted in the supplementalproposal in a closely related context, a500 ppm level for total toxic organicconstituents reasonably distinguisheswastes destined for material recoveryfrom wastes burned for nonrecoverypurposes because: (1) It represents aconcentration of material far exceedingtrace levels (generally measured insingle digit parts per million (ppm) ortens of ppm); (2) this level of hazardousconstituents could create an incrementalhealth risk if burned inefficiently, orwith inadequate emission controls; and(3) this level is high enough to indicatethat an objective of burning is wastetreatment-destroying nontrace levelorganics-as opposed to materialrecovery. (The Agency's earlier proposaldealt with the question of when a wastemight be considered to be indigenous toan industrial furnace burning formaterial recovery, and considered theissue of whether these devices wereburning for a material recovery purpose,and proposed the 500 ppm level adoptedin this rule as a means of objectivelyascertaining that purpose. 54 FR 43731.)

In order to be informed of personsclaiming this deferral, and in order todecrease potential abuse of the deferral,the Agency is requiring that all personsnotify the Agency if they assert thattheir smelting, melting, or refiningfurnaces are deferred from regulationwhen burning hazardous wastesbecause the purpose of the activity ismetal recovery. In addition, all suchpersons have to keep recordsdocumenting the basis for the claim (i.e.,that the wastes meet the Btu and totaltoxic organic constituent thresholds, thewastes contain recoverable levels ofmetals, and the device is indeedengaged in producing a metal productfor public use). Sampling and analysisprocedures specified in SW-846 must beused to make these determinations.These conditions are consistent withexisting § 261.2(f) which requires that allpersons claiming to be exempt orexcluded from regulation because of arecycling activity to have the burden ofproof demonstrating that they areentitled to the exemption or exclusion.In addition, the Agency notes that aconsistent recommendation of state andregional officials at the Agency's recent

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7144 Federal Register / Vol. 56, No. 35 f Thursday, February 21, 1991. f Rules and Regulations

public meetings on the regulatorydefinition of solid waste was to) providenotification and recordkeeping so thatregulatory officials know that a personis operating in an exempt status in orderto verify their claim. The Agency isacting on these recommendations in thisrule.

The Agency also notes that thederived from rule could apply to theresidues from metal recovery if metalsare being recovered from listedhazardous wastes. EPA believes this tobe explicit from the remand in API v.EPA discussed earlier. The Courtindicated that the Agency's explanationfor not establishing a treatmentstandard for the slag residue fromprocessing waste K06 was erroneous,.and remanded the case to the Agency toreconsider its explanation. 906 F. 2d at740-42. Implicit (or perhaps explicit)' inthis holding is the fact that the Courtviewed the residue as a hazardouswaste still coming under the terms of theK061 land disposal prohibition (theCourt referred repeatedly to "k0ol slag'and mentioned the derived from rule asthe basis for the slag being a hazardouswaste, id at 742), at least until theAgency provides a different explanationas to why the slag might not be ahazardous waste. Thus, because EPAhas not yet provided a new explanationregarding the indigenous principle (asexplained above), at the present time,EPA views residues from metal recoveryof listed hazardous wastes areconsidered to be derived from treatmentof hazardous waste and-thus hazardousthemselves unless some other principle(such as the Bevill amendment, orinsome cases, status under an authorizedstate program) operates to- achieve adifferent result.

Finally, the Agency notes that thedeferral applies only to the furnaceitself. The hazardous waste is subject totransportation and storage controls priorto introduction into the furnace. See§ 266.100(c).

The deferral of regulation of emissionstandards does not apply to cementkilns, aggregate kilns, and HAFs thatburn hazardous waste for purposesother than energy recovery. The Agencyhas studied these devices carefully anddetermined that the regulatorystandards in today's rule areappropriate for these devices when theyburn hazardous wastes for a purposeother than energy recovery..Consequently, the Agency sees noreason to defer emission standards forthese types of units.

Part Three Standards for Boilers andIndustrtat Furnaces, BUting HazardosWaste

Today's rule establishes controls foremissions. of particulate matter, toxicorganic compounds, toxic metals, andhydrogen chloride and free chlorine..Those controls are discussed below.

EPA notes that in some cases, today'srule potentially requires limitations onthe content of nonwaste input to a boileror industrial furnace that is burninghazardot s waste. For example,compliance with the limits for metals,Pl. and HCI/CIa requires controls notonly on the hazardous waste input butalso potentialy controls on other fuelsand industrial furnace feedstocks. EPAhas adopted this approach. not toregulate the nonwaste input to thesedevices, but rather to ensure thatburning hazardous waste in the devicedoes not pose unacceptable risks tohuman health and theenvironment.These limitations function as operatingconditions on the unit to ensurecompliance with the hazardous wasteemission standards. For example, unlesslimitations are established on nonwaateparameters,, owners and operators couldinitially demonstrate compliance byburning clean raw materials along withhazardous waste, and then change theirraw material input in a manner thatcauses emissions to increase.significantly. In addition, the approachadopted today allows owners andoperators maximum flexibility indemonstrating compliance with theemission standards by allowingadjustments to nonwaste input as ameans of achieving compliance. Thealternative of demonstrating complianceonly through alteration of hazardouswaste feed is not only less flexible, butwould create enormous administrativedifficulties (and add significant expense)for both regulated entities and Agencypermit writers. (For example, stackmonitoring might no, longer be a feasiblemeans of demonstrating compliancebecause one could not ascertain Whatportions of the emissions areattributable to burning hazardouswaste.). For these reasons, we think theapproach adopted today is the mostsensible means of demonstratingcompliance.

I. Emission. Standard for ParticulateMatter

Boilers and Industrial furnaces thatburn hazardbus waste may emitsubstantial quantities of particulatematter (PM). (Emissions of particulatematter canhave adverse effects onhuman health and the environment evenif toxics are not adsorbed on theparticulate matter. However, the

Agency's chief concern in this rule iscontrol of adsorbed toxins Becausetoxic metals and organic compoundsmay adsorb onto smaller size PM thatcan be entrained in the lungs.unregulated particulate emissions could,pose a significant threat to humanhealth. Although there may belimitations to the health-basedstandards, the metals and organicemissions standards promulgated intoday's rule- provide protection of publichealth based on current knowledgeabout toxic. pollutants and available riskassessment methodologies. The PMcontrol standard promulgated today willprovide additional protection byensuring that adsorbed metal andorganics are removed from stack gaswith the PM.

In today's rule, EPA is establishing astandard for boilers and industrialfurnaces which limits particulateemissions to 0.08 gr/dscf (grainstdrystandard cubic foot) corrected toc7%oxygen. This limit was chosen becauseit provides, a common measure ofprotection, from particulate emissionsfrom boilers, industrial furnaces, andincinerators burning hazardous waste.This standard may be redundant for: (1)A new, large capacity facility assigned'to a specific source category which, isgoverned by a New Source PerformanceStandard (NSPS); (2) a waste burningfacility located in a non-attainment areasubject to State Implementation Plan(SlIM standards; (3) a facility withstandards for metals and HCI emissionsthat result in particulate emissionsbelow 0.08gr/dscf; and (4) a facilitysubject to a stricter standard based onBest Avaitable Control Technology(BACT) imposed pursuant to the CleanAir Act's Prevention of SignificantDeterioration (PSD} program. In suchcases, the. device would be subject tothe- more stringent particulate matterstandard, not the RCRA 0.08 gr/dscfstandard, and the additional burden ofdemonstrating compliance with theapplicable particulate matter standardconeurrently with the applicableemissions standards in today's rule fororganic compounds, metals, and acidgases will not, be substantial Webelieve, however, that there are manysituations where a. BIF is either notcurrently' subject to a particulate matterstandard, or the, standards is higher thanthe RCRA 0.08 gr/dscf standard.

The Agency has considered loweringthe particulate standard to takeadvantage of technology advances madein: air pollutiorr control and to. beconsistent with the proposed standardof 0.015gr/'dscf for municipal wasteincinerators. (We note that the-proposed




standard for MWIs also served as asurrogate to control emissions of toxicmetals. 54 FR 52219. In contrast, today'srule has separate emission standards foreach toxic metal.) We are not preparedto do that at this time, however, becausewe have not conducted the studies toestablish an appropriate PM standardthat represents best demonstratedtechnology (BDT). Although manyboilers and industrial furnaces may beable to achieve a PM standard lowerthan 0.08 gr/dscf fin fact, the PM NSPSfor specific types of BIFs is lower than0.08 gr/dscf), we are not certain that allBIFs can meet a standard of 0.015 gr/dscf. This is because some industrialfurnaces have a very high (uncontrolled)particulate loading due to entrainedparticles of raw materials. Examples arecement kilns and light-weight aggregatekilns. Hence, a single PM standard of0.015 gr/dscf cannot now bepromulgated.

The Agency firmly believes that the0.08 gr/dscf PM standard, when used asa supplement to the risk-based metalcontrols provided by today's rule,provides protection of human health andthe environment. Given that hazardouswaste burned in BIFs could containvirtually unlimited concentrations oftoxic metals, the Agency believes thatrisk-based standards are needed tosupplement the PM standard forhazardous waste burning irrespective ofwhether the PM standard representsbest-demonstrated technology. Evenunder a PM standard as low as 0.015gr/dscf, a large fraction of the PMemitted from a hazardous wastecombustion device could be comprisedof toxic metals that could result insubstantial health risk.

Nonetheless, the Agency will considerif additional PM controls are warrantedto control emissions of toxic metals. Inthat evaluation, the Agency willconsider whether the additionalcontrols, if any, should be promulgatedin the future under the new Clean AirAct. See discussion in section UI.A ofpart One of this preamble. Finally, wenote that permit writers also couldimpose a lower PM standard wherefacts warrant, pursuant to the omnibuspermit authority in section 3005(c)(3).8

8 EPA notes that permit writers choosing toinvoke the omnibus permit authority ofI 270.32(b)(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

A. Basis for Final RuleParticulate matter (PM) is controlled

from combustion sources to limitemissions of toxic metals and PM per se(i.e., because of human health andecological impacts associated with PMthat does not contain toxic metals). Inthe May 6, 1987 proposed rule, EPAsuggested that a PM emission standardwas not needed for boilers andindustrial furnaces because the risk-based metals controls provide adequatecontrol of metals emissions. The Agencyreasoned that a standard intended tocontrol PM per se would be moreappropriately applied to these sourcesunder authority of the Clean Air Actrather than RCRA.

EPA received numerous comments onthe May 6, 1987 proposed rule suggestingthe need for a particulate standard forboilers and furnaces burning hazardouswaste. Many commenters believed that,notwithstanding the risk-based metalscontrols, unregulated PM emissions withadsorbed toxic metals and organiccompounds could pose a significantheath risk. In addition, threecommenters suggested that EPA addressthe issue of particulate control duringsoot-blowing cycles when levels ofparticulate emissions are 4 to 7.2 timesthe level of emissions under normaloperation. The Agency carefullyconsidered these comments andsubsequently determined that the risk-based metals standards should besupplemented with a PM standard toprovide a common measure of controlfor metals. This decision was based inpart on a consideration of commenters'concerns about the limitations of risk-based metals standards. See 54 FR43720-21. Hence, the Agencysubsequently proposed a particulateemissions standard of 0.08 gr/dscf(grains/dry standard cubic foot)corrected to 7% oxygen in the October26, 1989 supplement to the proposedrule. The standard would be applicableto all boilers and industrial furnaces notgoverned by a more stringent (NSPS orSIP) standard.

1. Alternatives Considered. Inselecting the standard for boilers andindustrial furnaces, the Agencyconsidered the following alternatives:(1) Apply the current NSPS standard forsteam generators burning waste; (2)apply the applicable NSPS; or (3) applythe existing hazardous waste incineratorstandard. These options are discussed inthe 1989 supplemental notice (54 FR43720).

Many commenters supported theproposed particulate standard of 0.08gr/dscf. Several commenters, however,opposed this limit, arguing against

imposing a standard appropriate forincinerators on boilers and furnaces.Still other commenters suggested thatthe 0.08 gr/dscf limit did not go farenough in protecting the public health.These respondents argued for a lowerlimit comparable to that the Agencyproposed for municipal wasteincinerators.

The Agency continues to believe thatthe 0.08 gr/dscf PM standard, when usedas a supplement to the risk-based metalcontrols provided by today's rule,provides substantial protection ofhuman health and the environment.

2. Basis for Standard. Today's rulepromulgates the proposed particulateemission limit of 0.08 gr/dscf because,as a supplement to the risk-based metalscontrols, it provides a common measureof protection from particulate emissionsfrom boilers, industrial furnaces, andincinerators burning hazardous waste.In addition to providing control ofparticulate metals and adsorbed organiccompounds, the 0.08 gr/dscf standardshould also ensure that the Clean AirAct's National Ambient Air QualityStandard (NAAQS) for particulates isachieved in most cases. An analysis ofexisting sites shows that emissions ofparticulates at 0.08 gr/dscf could resultin MEI levels of up to 30% of themaximum daily PMo (particulate matterunder 10 microns) NAAQS (150 mg/m).If background particulate levels at a siteare high (i.e., the site is in a attainmentarea), particulate emissions from thedevice should also be addressed as partof the State Implementation Plan (SIP)(as they are now for hazardous wasteincinerators in particulate non-attainment areas). Therefore, althoughthe 0.08 gr/dscf standard may notensure compliance with the NAAQS inevery situation, this issue will beaddressed by the SIP since the facilitywould be, by definition, in a non-attainment area for particulateemissions.B. Interim Status ComplianceProcedures

Facilities operating under interimstatus must comply with the PMemission standard. By the effective dateof the rule, owners/operators mustsubmit a certification of precompliancethat documents their use of engineeringjudgment to show that, considering feedrates of ash from all feed streams,partitioning of ash to bottom ash orproduct, and the PM removal efficiencyof the air pollution control system(APCS), PM emissions are not likely toexceed the 0.08 gr/dscf limit. Ownersand operators must also establish andprovide with the precompliance

7145




certification limits on feed rates- of ashin all feed streams! consistent with thoseused to determine that emissions ofparticulate matter are not likely toexceed the standard. The facility maynot exceed these feed rates duringinterim status (unless amended by arevised certification of'precompliance).Further, within 18 months (unlessextended) of promulgation, owners/operators. must conduct emissions.testing and certify that emissions do notexceed the limit. See section, VII in partThree of this preamble for moreinformation.

C. Implementation

Owners/operators must demonstratecompliance with the PM standard usingMethods 1-5 of=40, CFR part 60, appendixA. The compliance test for certificationduring interim status and the trial burnforfacilities applyingfor a RCRAoperating permit must be representativeof worst-case operating conditions withrespect to particulate emissions that willoccur during operation of the facility(i.e., because limits on operating,conditions applicable for the remainderof interim status will be based onoperating conditions during thecompliance test.

The PM standard is implemented bylimiting the feed, rate of ash from all feedstreams (Le., hazardous waste, otherfuels,, raw materials) and, by limits onAPCS-specific operating, parameters.The limits are. established during interimstatus based on. the compliance test, andin the operating permit based on thetrial bum.

The final rle gfves specialconsideration to cement and. light-weight aggregate kilns because their raw,material feed streams, contain the vastmajority of the ash input and resultingPM. Therefore, owners/operators ofcement kilns and light-werght aggregatekilns are not required to monitor ashfeed rates of feed streams.. Weemphasize, however, that cement kilnsand lightweight aggregate kilns, like all.BIFs, are still required to demonstrate.conformance with the PM emissiou.standard during a compliance test(under interim status} or trail burm(under a part B application). The Agencybelieves that the capacity limiton thefacility (expressed in appropriatm unitssuch as raw material feed vateland thelimiters othe air pollution control systmt(APCS) operafingparameters apphcablduring both hyterim status and unider asubsequent operatfing permit will ensurethat cement and hlit-weot kilho

continuously comply with the PMstandard.0

II. Controls, for Emissions of'TonicOrganic Compounds

Burning hazardous waste thatcontains toxic organic compounds (Le..organic compounds listed, in appendixVIII of 40 CFR part 2611 under poorcombustion conditions can result insubstantial, emissions of the toxic:compounds originally present. in thewaste as well as other compounds, due.to partial but incomplete combustion ofthe constituents in the waste.. Thequantity, of toxic organic compoundsemitted depends on the concentrations,of the toxic compounds in. the waste, thewaste firing rate (i.e., the percentage oftotal fuel provided by the hazardouswaste to the boiler or industrialfurnace), and the combustion conditionsunder which the waste is burned. Therisk posed by the emissions depends onthe quantity and toxicity ofthecompounds emitted and on the ambientlevels to which persons are exposed.Hypothetical risk assessments showthat under poor combustion conditionsthat achieve only 99 percent or 99.9percent destruction and removalefficiency (DREJ of organic compounds,risks to the maximum exposedindividual (MEI} from unburnedcarcinogenic organic& found inhazardous waste can result in increasedlifetime cancer risks of 10: 4. 10.

The Agency is controlling theemissions of toxic organic compoundsfrom boilers and industrial furnaces thatbum. hazardous waste with twoperformance standard&. First, a 99.99percent destruction and removalefficiency (DRE) standard, for principalorganic hazardous constituents (POHCSJin waste feeds. will ensure thatconstituents in the waste are not emitted.at levels that could pose significant riskin.virtually all scenarios of which theAgency ia&aware.' Second, limits on

9 We note,.mereover, thet seme boilers, and mansindustrial'furnaces ara already subject to aparticulate matter (PMlstandUntunder a NSPS, SIPor PSD proram and: the applicable PM standard iSgensray mna atdrnge tha the Mgr/d efstandard provided by today's rula.Thui, thxewdevices are already under a regulatory compliance~program for a PM standard We-note further thatthemore. stringent PMstandardappriee.

m Ehglneering-Science, Background InformationDocument for the- Dverapment of Regu la

tion toControl the Burning of Hazardous Waste in Boilers-and IndustriaL]Sismaces. Vohime:MrnaryW1(NTIS * P8 67 1 73MI.

" Except that Q.99M DRE is euire& lbrdioxin-listed ha-ardous-waste.

flue gas concentrations of carbonmonoxide (CO) and, where specifiedhydrocarbons (HQ will ensure thatcombustiona devices operatecontinuously at high combustionefficiency and emit products ofincomplete combustion (PICa) at levelsthat will not pose- adverse effects onpublic health and the environment. Thebasis for theset standards. is discussed'below.

A. DRE Standard

As, proposed, the; Agency ispromulgating a 99.9999% DREstandard L2' for those acutely hazardouswastes listed because they containdioxin 1 3 (and waste mixed with thosewastes), and. 9.99 percent DREperformance standard for all otherwastes. This standard is protective, itcan be readily achieved by boilers andindustrial furnaces, and it will ensurethat the Agency's controls are consistentfor all. combustion devices (boilers,industrial furnaces, and incinerators)that pose similar risks.

Hypothetical risk assessments haveshown, that a 99.99 percent DIREstandard for POHCs is. protective ofrisks posed by emissions of organicconstituents in the waste in virtuallyevery scenario of which the. Agency isaware. 1 ' (EPA considers elsewhere Inthis notice the issue of products ofincomplete combustion.) Increasedlifetime cancer risks to the maximumexposed individual (MEl from anincinerator operating at 99.99'percentDRE would generally be 10"6 or less.Threshold (i.e., noncarcinogenic)l organic.compounds also would not be expectedto be present in emissions fromhazardous waste burned' in boilers andindustrial furnaces at levels that couldpose a health hazard under the 99.99percent DRE standard.

EPA i awrem,. however, that the DREstandard does not directly control themass emissionrate (e.g, pounds per'hour) o1unburned toxic organicconstituents: in the waste. Althoughthree are hypothetical situations inwhich risks- from POHCs could besignificant under a 99.99 percent DREstandaed (e.g, boilers or industrialfurmaces located in urban areas bumrimhigh volumes of waste with higconcentrations of highly potentcarcinogenic organics), the Agency isnot aware that any such situations are'

Is The propose4formuli for calculating DRE hatbeen revised in the final rls (sea t 26&1e4al to,make it matliematiealy cozrectconsidering use ofsignificant figures.

is EPA.Hazardaus Wastas FP20. E02X. F022F023, F02M and F022.

14 Engineering Science, op. cit.




actually occurring. If, however, duringthe permit process, it appears that ahigh-risk scenario may exist, permitofficials may use the omnibus permitauthority' 5 of section 3005(c)(3) of theResource Conservation and RecoveryAct (RCRA) codified at § 270.32(b)(2) todevelop permit requirements, asnecessary, to protect human health andthe environment (e.g., by requiring a99.9999 percent DRE, by limiting the feedrate of particular toxic compounds, orby setting a mass emissions rate).

1. Selection of POHCs for DRE Testing

In the April 27, 1990 proposed rule toamend the incinerator standards (55 FR17890), EPA outlined the considerationsto be made by applicants and permittingofficials in selecting POHCs for DREtrial burns. Given that the DREimplementation procedures for boilersand industrial furnaces (BIFs) areidentical to those for incinerators, thediscussions in the incinerator proposedrule are pertinent to this rule.

A major factor in selecting a POHCfor DRE testing is its incinerabilityrelative to other toxic organiccompounds. A number of indices can beused to predict incinerability includingheat of combustion, autoignitiontemperature, thermal stability underexcess oxygen conditions, and thermalstability under low oxygen(substoichiometric) conditions. Anincinerability ranking based on thermalstability at low oxygen concentrations(TSLoO,) shows promise and iscurrently seeing widespread use inincinerator permits. A number ofcommenters responded to EPA's requestfor comment on the use of the TSLoO,index for POHC selection. In general,they raised no problems with use of theindex. Their main concern appeared tobe that EPA choose one index and applyit consistently.

The Agency, however, is not requiringthe use of a particular index. Due to thevarious "failure modes" differentorganic compounds are susceptible toduring the destruction process in acombustion device, and the evolvingstate of knowledge in this area, theAgency feels that the POHC selectionprocess is technically complex, and thatit should involve a number of

1 I EPA notes that permit writers choosing toinvoke the omnibus permit authority ofI Z70,.32b(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

considerations, rather than simply oneincinerability ranking. Thus, EPAinstead recommends that permit writersand applicants consider these indicesand other relevant factors and use theirjudgment and applicable guidance on acase-by-case basis to select POHCs forthe trial burn.

2. Use of POHC Surrogates

A number of laboratory-scale, pilot-scale, and field-scale tests have beenconducted to investigate the use ofnontoxic tracer surrogates (e.g., sulfurhexafluoride (SF6)) rather than POHCsselected from appendix VIII of part 261.Sulfur hexafluoride, in particular, showspromise as a conservative tracersurrogate for compounds which aresusceptible to the thermal failure mode(i.e., it is difficult to destroy unlesssufficiently high temperatures arereached). It is readily availablecommercially, and is inexpensive andnontoxic. POHCs that are listed onappendix VII, especially in situationswhere spiking is required to increaseconcentrations in a waste for DREtesting, are often difficult to obtain, areexpensive, and are a health hazard tooperators. Sampling and analysistechniques for SFs are well documentedbecause of its long use as a tracer gasfor monitoring ambient air and are morestraightforward (simpler) and lessexpensive than sampling techniques forappendix VIII, part 261, compounds (e.g.,VOST and MM5).

Numerous commenters responded toEPA's request for information on anapproach for simplifying andstandardizing DRE testing. Commenterssupported standardization of DREtesting provided the approach isequitable for all boilers, industrialfurnaces, and incinerators. Commentswere received in support of all threeapproaches proposed by EPA ("POHCsoup," surrogates, and specific wasteanalysis). Commenters generallysupported use of surrogates in lieu ofextensive waste analysis for design ofDRE tests. Other commenters suggestedusing a limited number of major wasteconstituents as POHCs, such as carbontetrachloride, perchloroethylene,trichloroethylene, andmonochlorobenzene, until it can beshown that a universal surrogate, suchas sulfur hexafluoride (SF6), iscomparable in demonstrating DREperformance. Sulfur hexafluoride wasrecommended by some commenters as agood surrogate choice based on the highaccuracy of results with the compoundand ease of use.

However, since the April 27 proposedrule, data have become available

showing cases where other organiccompounds were more difficult todestroy than SF6 under conditions oflow oxygen. This is consistent withtheory, since SF6 can be destroyed underconditions of high temperature and lowoxygen relatively easily compared tocompounds which need oxygen todecompose. Thus, although SF6 appearsto show promise as a surrogate fortesting the thermal failure mode becauseof its stability at high temperatures, itdoes not appear to be adequate as a"universal" surrogate, since it does rottest for low oxygen or "mixing" failure.

Nevertheless, today's rule explicitlyallows the use of surrogate, nontoxiccompounds for selection as POHCs forDRE testing. As for any other type ofPOHC, the use of such compounds mustbe approved on a case-by-case basis bypermit officials based on technicalsupport provided by the applicant. Theapplicant's trial burn plan mustadequately document the correlationbetween the DRE of the surrogatecompound and the DREs of theappendix VIII compounds anticipated tobe burned at the facility under thefacility's permit.

3. Waiver of DRE Trial Burn for BoilersOperating Under the Special OperatingRequirements

In 1987, the Agency proposed to waivethe trial burn requirement todemonstrate DREs for boilers thatoperate under special operatingrequirements (SOR). The SOR requiredthat, in addition to meeting the proposed100 ppmv CO limit, a qualifying boilermust: (1) Burn at least 50 percent fossilfuel in the form of oil, gas, or coal; (2)operate at a load of at least 25 percentof its rated capacity; (3) burn hazardouswaste fuel with an as-fired heating valueof at least 8,000 Btu/lb; and (4) inject thehazardous waste fuel through anacceptable atomization firing system.

The SOR were based on the results ofnonsteady-state boiler testing. Fromthese results, the Agency believed thatboilers operating under the SOR wouldmaintain a hot, stable flame conduciveto maintaining high combustionefficiency, resulting in maximumdestruction of organic constituents inthe hazardous waste fuel. The Agencybelieved that these boilers wouldachieve at least 99.99 percent DRE, andtherefore, a trial bum to demonstrateDRE would not be necessary.

The Agency continues to believe thatboilers operating under the SOR willachieve 99.99 percent DRE. However,based on comments received on theproposed SOR and on furtherexamination of the previous steady-

7147




state and nonsteady-state boiler testresults, the Agency has made thefollowing modifications to the SOR:

(1) Limit eligibility for the waiver tononotoker, watertube boilers;

(2) Revise the requirement that theboiler fire 50 percent fossil fuel or fuelsderived from fossil fuel to include talloil, to allow permit officials to approveon a case-by-case basis othernonhazardous fuels with combustioncharacteristics comparable to fossil fuel,and to require for all such primary fuels(i.e., fossil fuels, tall oil, and other fuelsapproved on a case-by-case basis) aminimum heating value of 8,000 Btu/lb;

(3) Clarify that the hazardous wastefuel fired must have an as-fired heatingvalue of 8,000 Btu/lb and require thateach fuel fired in the burner wherehazardous waste is fired must have anas-fired heating value of 8,000 Btu/lb;

(4) Increase the minimum loadrequirement from 25% to 40%; and

(5) Eliminate the lower viscosityrequirements for the hazardous wasteand decrease the upper viscosity limitsfor the hazardous waste to 300 seconds,Saybolt Universal (SSU), measured atthe as-fired temperature of the fuel.

As proposed in 1987, boilers with atrial burn waiver under the SOR mustmeet the Tier I CO limit of 100 ppmv 16and must comply with all otherrequirements of the final rule (e.g.,metals standards, PM limit].

The revised SOR are presented below,along with the basis for the revisions.

a. The Boiler Must Be a Nonstoker,Watertube Boiler. Commenters statedthat the nonsteady-state testing of onlythree stoker and firetube boilers isinsufficient to determine whether 99.99percent DRE would always be achievedunder the SOR. Commenters alsomaintained that the stoker and firetubeboilers tested were not representative ofall types and sizes.

The Agency agrees that there islimited data demonstrating that stokerand firetube boilers can achieve 99.99%DRE under the SOR. In the Agency'ssteady-and nonsteady-state testing, onlythree firetube boilers and one stokerboiler were tested under steady-stateconditions, and one stoker boiler wastested under nonsteady-state conditions.The remainder of the boilers tested werewatertube boilers.

The results from one of the firetubeboilei tests generally support the abilityof firetube boilers to achieve 99.99

15 Boilers complying with the Tier II PIC controlswhere CO levels exceed 100 ppmv are not eligiblefor the automatic waiver of the DRE trial burn. Thisis because the DRE test data used to support thewaiver was obtained for boilers operating at COlevels below 100 ppmv.

percent DRE, but this boiler wasspecially designed to combusthazardous waste. The Agency isconcerned whether more conventionallydesigned firetube boilers could easilyachieve this level of DRE. DREs couldnot be calculated at one of the otherfiretube boiler tests due to inadequatewaste feed levels, and sampling andanalytical problems occurred at thethird firetube boiler test. The stokerboiler tested under steady-stateconditions did not demonstrate 99.99percent DRE. In addition to the limiteddata for these boiler types, a greaterpotential exists for poor distribution ofcombustion gases and localized coldspots in firetube and stoker boilers thatcan result in poor combustionconditions. This is because these boilersgenerally burn fuels with a large andvariable particle size on a bed, thus,making even distribution of combustionair difficult. Therefore, the final ruleprecludes stoker or firetube boilers fromthe automatic waiver of a DRE trialburn.

b. A Minimum of 50 Percent of theFuel fired to the Boiler Must Be HighQuality "Primary" Fuel Consisting ofFossil Fuels or Fuels Derived FromFossil Fuels, Tall Oil, or, if Approved ona Case-By-Case Basis, OtherNonhazardous Fuel Comparable toFossil Fuel, and All Such Primary FuelsMust Have a Minimum As-FiredHeating Value of 8,000 Btu/lb. Thirteencommenters found the 50 percent fossilfuel requirement to be overly restrictive.In particular, one commenter proposedthat the requirement be rephrased toallow the burning of no more than 50percent hazardous waste in mixturessuch that nonhazardous waste fuelsupplements can be fired. Anothercommenter suggested eliminating thefossil fuel requirement for wastes thathave heating values comparable to fossilfuels. Eleven commenters supported theburning of high quality non-fossil fuels,such as tall oil (i.e., fuel derived fromvegetable and rosin fatty acids) and theby-products derived from the fractionaldistillation of tall oil. Many of thesecommenters said they have burnedthese materials and claimed they haveheating values and combustioncharacteristics similar to fossil fuels.Three commenters requested that theburning of wood wastes as a primaryfuel be allowed. One of thesecommenters presented the results fromsix trial burns for wood waste boilerswhich demonstrated that combustionzone temperatures in these types ofboilers are consistent, and that a hot,stable flame conducive to thedestruction of organic constituents in

the waste is present under theseconditions.

Based on the comments andinformation presented regarding the useof tall oil (i.e., tall oil burns likecommercial fuel oil), the Agency isrevising the 50% primary fuelrequirement to include tall oil. Also, theAgency believes that the combustion ofother nonhazardous fuels that haveheating values of at least 8,000 Btu/lb(representing the lower heating valuerange of most sub-bituminous coals),and combustion characteristics similarto fossil fuels, will ensure a hot, stableflame conducive to the destruction oforganic constituents in the waste. Anowner/operator who is planning to burnsuch a fuel supplement must presentinformation on the supplement's-combustion characteristics for theDirector's review. Concerning woodwastes, the Agency continues to believethat these wastes may not provide thehot, stable combustion zone conditionsneeded to achieve 99.99 percent DRE.Due to the higher flue gas moisture,excess air, CO levels, and lower furnacetemperatures accociated with woddfiring, the potential for less than 99.99percent DRE exists. Therefore, boilersthat fire wood wastes must demonstrateDRE capabilities through a trial burn.

The 50 percent minimum primary fuelrequirement, on a total heat or volumeinput basis, whichever results in thegreater volume of primary fuel, also isneeded to ensure appropriatecombustion zone conditions. This limitwas based on the maximum levels ofhazardous waste burned in the boilerstested by EPA under nonsteady-stateconditions.

Finally, the Agency recognized thatthe term "fossil fuel" can include peat orother fuels with heating values below8,000 Btu/lb. Because the test data usedto support the waiver were from boilersfired with primary fuels with heatingvalues higher than 8,000 Btu/lb, the finalrule applies the minimum 8,000 Btu/lbas-fired heating value limit to all fuels,including fossil fuels, used to meet theminimum 50% primary fuel requirement.

c. Boiler Load Must Be at Least 40Percent. Several commenters addressedthe proposed minimum load level of 25percent. Only one commenterconsidered it to be too low. Thiscommenter advocated an 80 percentload requirement unless high efficiencycombustion can be demonstrated at thetrial burn. One commenter consideredthe 25 percent requirement to bearbitrary, but within current practice.Another commenter recommended thatthe level be more flexible for multipleburner boilers. One commenter




recommended that the requirement tomaintain a boiler load of 25 percent beeliminated if the Btu value of the wastesburned is equivalent to that of coalthereby providing the heat inputnecessary to sustain normal combustionoperations.

Boiler testing conducted at a load aslow as 26 percent has demonstrated thatcertain boilers can achieve 99.99 percentDRE when operated at low loads.However, due to concerns related toflame stability, combustion control, andheat transfer effects associated withload turndown on some boilers, theAgency has raised the boiler load limitfrom 25 percent to 40 percent of designload. Operation of some boilers at loadsof less than 40 percent can result insignificantly higher excess air levels andlocalized decreases in flametemperatures. In addition, most of theboilers tested to develop the operatingrequirements operated at loads above40%. Therefore, limiting the boiler to 40%is more consistent with the availabletest data. If an owner/operator expectsto operate a unit at a lower load whilefiring hazardous waste, a trial burn todemonstrate 99.99 percent DRE isrequired.

d. The Heating Value of theHazardous Waste Fuel Must Be at Least8,000 Btu/lb, As-Fired, and Each FuelFired in a Burner Where HazardousWaste Is Fired Must Have a HeatingValue of at Least 8,000 Btu/lb, As-Fired.Eleven commenters expressed concernthat the "as-fired" requirement proposedin 1987 will require the blending ofwastes that have heating values of lessthan 8,00 Btu/lb with other wastesand/or the primary fuel beforeatomization. Four commentersdocumented a number of problems withblending low Btu wastes, includingimmiscibility and other mixingproblems, increased quantity ofmaterials requiring handling, difficultyof controlling feed during unit upsets,and impracticality for coal-firedsystems. Five commenters requestedthat the heating value be determined ona total-burner basis, as a composite ofprimary fuel and waste. Threeadditional commenters recommendedthat the minimum heating value ofwastes be lowered to 5,000 Btu/lb.

The Agency agrees that waste fuelblending can present problems in someinstances. However, the Agency isconcerned that allowing low Btu wastesto be fired separately from the fuel andthen atomized in the flame region of theburner might make it difficult to ensuregood atomization, proper feed systemoperation, and, consequently, adequatecombustion of the hazardous waste.

Therefore, the 8,000 Btu/lb requirement,which represents the lower range ofheating values of fossil fuels, applies tothe as-fired heating value of thehazardous waste and to the as-firedheating value of any other fuel fired inthe same burner with the hazardouswaste."

If fiazardous waste with a heatingvalue below 8,000 Btu/lb 18 is mixed withthe "primary" fuel to meet the as-firedminimum heating value for hazardouswaste of 8,000 Btu/lb, that quantity ofprimary fuel may not be counted towardthe 50% primary fuel requirement. Thisis because the purpose of requiring 50%of the fuel to be "primary" fuel is toensure a hot, stable flame to combustthe hazardous waste. If a portion of theprimary fuel is blended with thehazardous waste to increase the heatingvalue of the hazardous waste as-fired,then that portion of the primary fuel isnot providing the hot, stable flame.

The following example shows howthis requirement will work. Suppose aboiler is fired with 70% primary fuel and30% hazardous waste, and that half ofthe primary fuel is blended with thehazardous waste to achieve an as-firedheating value of 8,000 Btu/lb. This boilerwould not be eligible for the automaticwaiver of the DRE trial burn because itis fired with only 35% primary fuel (halfof the 70%} that is not blended with thehazardous waste to meet the minimumas-fired heating value limit of 8,000 Btu/lb.e. The Hazardous Waste Must Be

Fired with an Atomization System.Seven commenters argued that lowerviscosity limits are unnecessary. Threecommenters stated that it is common toatomize wastes well below 150-200 SSU,and that No. 2 oil has a viscosity of 32.6-37.9 SSU at 100 'F. One commenterindicated that the upper viscosity limitsappear high for the atomization systemsspecified. One commenter disagreed andsaid that the high limits are in thecorrect range. Six commentersexpressed concern that the particle sizelimits are overly restrictive. One

17 We note that the 8,000 Btu/lb minimum heatingvalue also applies to the "primary" fuel that mustcomprise at least 50% of the boiler's fuelrequirements. However, the remainder of theboiler's fuel requirements may be provided byhazardous waste and other fuels. There are norestrictions on the other fuels unless they are firedin the same burner with the hazardous waste. Inthat case, those other fuels, like the hazardouswaste and "primary" fuel, must have a minimumheating vaue of 8,000 Btu/lb.Is We note that as discussed elsewhere in the

text, the sham recycling policy stays into effect untilan existing facility certifies compliance with theemissions standards (see I 266.103[c)). Thus, untilthat time, hazardous waste burned in a BIF musthave an as-generated heating value of 5,000 Btu/lb,unless the waste Is burned solely as an ingredient.

commenters stated that diverse wastestreams can be handled to achieve gooddestruction without particle size limits.Another commenter disagreed with EPAby stating that they are not familiar withnozzles designed for particle sizes assmall as 200 mesh. Three commenterssaid the waste viscosity should be left tothe discretion of the owner/operatorsince it is industry practice to operate atviscosities which provide optimumatomization.

Based on the commenters' arguments,the Agency has eliminated the lowerviscosity requirements and reduced theupper limit to 300 SSU (Seconds, SayboltUniversal) measured at the as-firedtemperature of the hazardous waste. Weeliminated the lower level because, afterconsideration of comments and re-evaluation, we believe that the concernstated at proposal-formation of a fog atlow viscosity levels which could resultin poor combustion conditions-is notlikely to occur. At proposal, the Agencyestablished upper viscosity limitsranging from 300 to 5,000 SSU,depending on the type of atomizationsystem. Commenters noted that, as apractical matter, wastes with as-firedviscosities greater than 300 are not firedin an atomization system. Thesemodifications will give facilities theflexibility to preheat wastes beforeatomization and are consistent withgeneral industry practice for goodatomization.

Regarding particle size limits the finalrule establishes the proposed limits.When high pressure air or steamatomizers, low pressure atomizers, ormechanical atomizers, 70% of the wastemust pass a 200 mesh (74 micron)screen. When a rotary cup atomizer isused, 70% of the waste must pass a 100mesh (150 micron) screen. These meshsizes are consistent with the designdroplet size of the atomizers.

Owners/operators of boilers whopropose to fire hazardous waste outsidethese viscosity and particle size limitsmust conduct a DRE trial burn.

B. PIC Controls

The burning of hazardous waste, likevirtually any combustion process,results in emissions of incompletelyburned organic compounds, or productsof incomplete combustion (PICs). PICscan be unburned organic compoundsthat were present in the waste, thermaldecomposition products resulting fromorganic constituents in the waste, orcompounds synthesized during orimmediately after combustion. If adevice is operated under poorcombustion conditions, substantialemissions of PICs can result (even if

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99.99% DRE is demonstrated for POHCs;this just means that the POHC is notbeing emitted in its original form).However, it should be noted thatestimates of risk to public healthresulting from PICS, based on availableemissions data, indicate that PICemissions do not pose significant riskswhen BIFs and incinerators are operatedunder good combustion conditions.

Nonetheless, the Agency is concernedabout the potential health risk from PICsbecause the available information hasserious limitations. It is very difficult toidentify and quantify emissions ofthousands of different compounds, someof which are present in minutequantities. Although elaborate andexpensive sampling and analyticaltechniques have been developed thatcan identify many PICs, many otherscannot be identified and quantified withcurrent techniques. Further, healtheffects information adequate to conducta health risk assessment consideringexposure via direct inhalation is notcurrently available on many organiccompounds that may be emitted fromcombustion systems. Finally, theavailable public health andenvironmental risk assessment tools areincomplete. Data are currently availableto conduct indirect exposure analyses(e.g., exposure via the food chain,drinking water, dermal exposure) ononly a few organic compounds, and itwill be some time before the Agencywill be able to quantify impacts onecological resources on a site-specificbasis for purposes of establishingemissions standards.

Given the limited information aboutthe hazards that PIC emissions maypose, EPA believes it is prudent torequire that boilers and industrialfurnaces operate at a high combustionefficiency to minimize PIC emissions.

EPA is promulgating today a two-tiered approach to control PICs asdiscussed in the October 29, 1989,supplemental notice (54 FR 43721-28).Under Tier I, CO is limited to 100 ppmv.Under Tier II, the Agency is providingan alternative standard. The facilityneed not meet the 100 ppmv CO limitprovided the facility can demonstratethat the hydrocarbon (HC)concentration in the stack gas does notexceed a good operating practice-basedlimit of 20 ppmv. The alternative COlimit under Tier II must be establishedduring the test burn based on theaverage over all runs of the highesthourly rolling average for each run.

1. Use of a CO Limit to Control PICs.

Generally accepted combustiontheory holds that low CO flue gas levelscombined with low CO flue gas levels

combined with low excess oxygen levelsindicate a boiler, industrial furnace, orincinerator is operating at highcombustion efficiency. Operating underhigh combustion efficiency helps toensure minimum emissions of unburned(or incompletely burned) organics. In thefirst stage of the combustion ofhazardous waste fuel, the POHCsthermally decompose in the flame toform other, usually smaller, compoundstermed products if incompletecombustion. In this first stage ofcombustion, these PICs also decomposeto form CO.

The second stage of combustioninvolves the oxidation of CO to CO2

(carbon dioxide). The CO to CO 2 step isthe slowest (rate-controlling) step in thecombustion process because CO isconsidered to be more thermally stable(difficult to oxidize) than otherintermediate products of the combustionof hazardous waste constituents.Because fuel is being fired continuously,these combustion stages occursimultaneously.

Thus, in the waste combustionprocess, the "destruction" of POHCs isindependent of flue gas CO levels. COflue gas levels cannot be correlated withDREs for POHCs, and may also notcorrelate well with PIC destruction.Although some emissions data indicatea weak correlation between CO andPICs, the data generally indicate thatthere is a relationship between the twoparameters: When CO is low, PICemissions are relatively low. Theconverse may not hold: when CO ishigh, PICs may or may not be high.

Low CO is an indicator of the statusof the GO to CO 2 conversion process,the last rate-limiting oxidation process.Because oxidation of CO to CO 2 occursafter the destruction of a POHC and its(other) intermediates (PICs), the absenceof GO is a useful indication of POHCand PIC destruction. The presence ofhigh levels of CO in the flue gas is auseful indication of inefficientcombustion, and at some level ofelevated CO flue gas concentration, isan indication of the failure of the PICand POHC destruction process.

EPA believes it is necessary to limitCO levels to levels that are indicative ofhigh combustion efficiency because theprecise CO level that indicatessignificant failure of the PIC and POHCdestruction process is not known. Infact, this critical CO level may dependon site-specific and event-specificfactors (e.g., fuel type, fuel mix, air-to-fuel ratios, and the rate and extent ofchanges in these and other factors thataffect combustion efficiency). EPAbelieves that limiting CO levels is alsoreasonable because: (1) It is a widely

practiced approach for monitoringcombustion efficiency-some boilersand industrial furnaces are alreadyequipped with CO monitors, and manyare equipped with flue gas oxygenmonitors; (2) the monitors may pay forthemselves through fuel savingsresulting from operation of the boiler orindustrial furnace closer to maximumcombustion efficiency; and (3) well-designed and well-operated boilers andindustrial furnaces can readily beoperated in conformance with either the100 ppmv CO limit under Tier I, or the 20ppmv HC limit under Tier II.

2. Tier I PIC Controls: 100 ppmv COLimit

a. Basis for the 100 ppmv CO Limit.The May 6, 1987 proposed rule wouldhave applied the same CO emissionlimits to all boilers and industrialfurnaces: a lower limit of 100 ppmv overan hourly rolling average and a 500ppmv limit over a 10-minute rollingaverage. The hazardous waste feedwould be shut off automatically if eitherlimit was exceeded. However, thehazardous waste would be cutoffimmediately once the 500 ppmv limitwas exceeded while the waste feedwould be cutoff within 10 minutes if the100 ppmv limit was exceeded. Further ifthe hazardous waste feed was cutoffmore than 10 times in a month, theproposed rule would have prohibitedfurther hazardous waste burningpending review and approval byenforcement officials. The lower limit of100 ppmv was selected as representativeof steady-state high efficiencycombustion conditions resulting in PICemissions that would not pose asignificant risk. The higher limit of 500ppmv was proposed to limit thefrequency of emission spikes thatinevitably accompany routineoperational "upsets," such as loadchanges and start-ups of waste firing.

While two commenters stated that theproposed 100 ppmv CO limit is arbitrary,six commenters supported the Tier I COlimit of 100 ppmv. One commentersupported both the 100 ppmv CO limitover an hourly rolling average, and the500 ppmv CO limit over a 10-minuterolling average. Three additionalcommenters also expressed support forthe 500 ppmv CO limit over a 10-minuterolling average. Three other commenterssupported a 500 ppmv CO limit over anhourly rolling average, and stated that amaximum 1,000 ppmv CO limit can beincluded in addition to a 10-minuteaverage.

Many commenters opposed the COtrigger limits and associated limits onthe number of waste feed cutoffs




proposed in May 1987. Primarily,commenters objected to one set of COemission limits as applicable to allboilers and industrial furnaces. Further,they argued that PIC emissions will notbe significant if, when the waste feed iscutoff, the combustion chambertemperatures are maintained while thewaste remains in the chamber. Sixcommenters argued that the triggerlimits will result in increased NO.emissions. One commenter stated thatNO. and CO cannot be loweredsimultaneously, and added that manylow NO. boilers may not be able to meetthese CO limits. As an alternative, onecommenter stated that a higher Tier ICO limit should be allowed for lesstoxic emissions: however, thiscommenter did not provide analternative approach for identifying thetoxicity of emissions. One commentersuggested that EPA retain twoalternatives to the CO standard:establishing an alternative standardbased on nonmethane, ethanehydrocarbon (NMEHC) emissions, and acase-by-case risk assessment approach.

As a result of these and othercomments and further evaluation, EPAis promulgating the Tier I limits basedon a maximum hourly rolling averageCO limit of 100 ppmv, corrected to 7percent flue gas oxygen content. If thislimit is exceeded, the hazardous wastefeed must be automatically andimmediately cutoff. The final rule doesnot restrict the number of waste feedcutoffs because: (1) Combustionchamber temperatures must bemaintained after a cutoff; and (2) thenumber of cutoffs will be minimized byallowing CO concentrations to beaveraged over a 60-minute period (i.e.,the hourly rolling average) and by therecommended use of pre-alarms toprovide time to remedy the problem orto allow a staged waste cutoff beforereaching the CO limit. Nonetheless, theAgency retains the authority to limit thefrequency of cutoffs as the factswarrant. See § 266.102(e)(7](ii). The finalrule does not include the proposed 500ppmv rolling average over a 10-minutelimit on CO because we do not believe itis needed given that the final rulerequires immediate waste feed cutoffwhen the 100 ppmv hourly rollingaverage limit is exceeded. In addition,several commenters argued that the 500ppmv limit was arbitrary.

In addition, EPA is promulgatingalternative (Tier II) standards (discussedbelow), as discussed in the October 1989supplemental notice, for control of PICemissions from boilers and industrialfurnaces. The Agency believes that thealternative controls will allow facilities

flexibility in meeting both the PICcontrols and NO. emissions standards(imposed under different regulatoryauthorities) simultaneously. The Agencybelieves that the alternative, Tier IIstandards for control of PIC emissionsare needed to address issues andconcerns raised by commenters on theproposed rule.

The 100 ppmv CO limit promulgatedtoday for Tier I is indicative of steady-state (i.e., normal), efficient combustionconditions. The time-weighted averagefor the CO limit is provided toaccommodate the CO spikes thatinevitably occur during routine "upsets,"such as when hazardous waste fuelfiring starts, when there is a load changeon an industrial boiler, or when thecomposition of fuels varies. Given thatCO is a sensitive indicator of overallcombustion conditions, and that it maybe a conservative indicator of POHCand PIC destruction, EPA isimplementing CO control limits basedon time-weighted averages ofexceedances rather than implementingfixed CO limits. Fixed limits that do notacknowledge inevitable CO spikes andthat do not give owners and operatorstime to adjust combustion conditionsactually could result in greateremissions of PICs because each timehazardous waste firing is interrupted,CO concentrations increase, andemissions of incompletely burnedorganics may also increase. (Note,however, that there is a requirement tomaintain combustion chambertemperature after a waste feed cutoffwhile waste remains in the chamber thatis intended to minimize HC emissionsafter a cutoff.) Thus, any controls on COmust balance the effects of organicemissions that may result from overlystringent CO limits that require frequentwaste feed interruptions with the effectsof emissions resulting from less stringentcontrols that acknowledge inevitableCO spikes.

The Agency has considered whetherthe 100 ppmv CO limit is, in fact, toostringent given that we acknowledge thelimit was chosen from within the rangeof reasonable values that may beconsidered indicative of goodcombustion conditions-50 to 250 ppmv.We attempted to obtain CO/timeprofiles from a number of well-operateddevices to determine the percentage oftime the facilities operated withinparticular CO ranges. 19 We thought to

1 "Energy and Environmental ResearchCorporation, "Guidance on Metal and PICEmissions from Hazardous Waste Incinerators",Final Report. September 21, 1990.

use this data to predict the frequency ofwaste feed cutoffs that would berequired at various CO limits.Unfortunately, the analyses could not beconducted because the facilities weevaluated were operating under specificCO limits and their CO levels neverexceeded those limits when burninghazardous waste. We found that thefacilities learned to comply with the COlimits they had to meet.

Moreover, we believe that the 100ppmv CO limit is reasonable for anumber of reasons. Not only is it withinthe range of CO levels that areindicative of good combustionconditions, but the Agency believes thatit is not too low because: (1) It is higherthan the technology-based 50 ppmv COlevel EPA requires for boilers burningwaste PCBs (see 40 CFR part 761); (2) itis higher than the CO limits included inmany hazardous waste incineratorpermits; 20 (3) the Agency explicitlyencourages the use of pre-alarms tominimize the frequency of automaticwaste feed cutoffs; 21 and (4) the limit isimplemented on an hourly rollingaverage basis which allows andminimizes the effects of short-term COspikes.

We also note that the Agency maysoon promulgate regulations formunicipal waste combustors (MWCs)that, among other controls, may limit COconcentrations to 50, 100, or 150 ppmv(as proposed), depending on the type ofMWC, over a four hour rolling averageand dry-corrected to 7% oxygen. TheMWC limits are technology-based-theyrepresent levels readily achievable bywell-designed and well-operated units.EPA does not believe that the MWClimits present a conflict with the 100ppmv (with provisions for an alternativehigher limit if HC concentrations areless than 20 ppmv) limit for BIFs undertoday's rule. The Agency is confidentthat the BIF rule is protective becausethe Agency has determined that, whenCO levels are less than 100 ppmv, PICemissions do not pose significant risk.Thus, although the 100 ppmv limit is nota best demonstrated technology-basedlimit (many BIFs (and hazardous wasteincinerators) readily operate at COlevels well below 100 ppmv), the 100

10 We note that the Agency proposed on April 27,1990 to apply to hazardous waste incinerators thesame CO/HC limits that today's rule applies toBlFs.

2 1If the CO limit is "too low" for a given facility'sdesign and operating conditions, then frequentwaste feed cutoffs may occur. Frequent waste feedcutoffs may actually increase PIC emissionsbecause the resulting perturbation to thecombustion system may upset the termperature,oxygen, fuel relationships needed for completecombustion.

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ppmv CO limit will ensure protection ofhuman health and the environment.

As stated above, the CO limits arebased on a flue gas oxygen content of 7percent. One commenter indicated thatEPA's reasoning for using the COcorrection of 7 percent oxygen is notclear. The commenter believes the 7percent correction factor is unfair forthermal units which, under normalconditions, need to operate at oxygenlevels greater than 7 percent, yet operatewith low levels of CO and HCs. EPAbelieves that correcting CO levels forflue gas oxygen content is necessarybecause without this correction, high COflue gas concentrations could be dilutedby high rates of excess oxygen. Intoday's rule, EPA is requiring that CO becorrected to a flue gas oxygen content of7 percent because the majority of boilersand industrial furnaces achieve highcombustion efficiency at optimum fluegas oxygen levels ranging from 3 percentto 10 percent. The optimum oxygen levelto achieve high combustion efficiencyfor a given device will vary dependingon factors such as fuel mix and boilerload. In general, large combustiondevices (in terms of heat input capacity)have optimum oxygen requirements onthe low end of the range of oxygencontent, while smaller units requirehigher oxygen levels. EPA believes thata correction level of 7 percent isreasonable since this oxygen level is inthe middle of the range of typicaloperation for all devices and since themajority of devices burning hazardouswaste fuels have moderate heat inputcapacities (e.g., 20-150 MM Btu/hr). Inaddition, 7 percent oxygen is thereference level for the existingparticulate standard for hazardouswaste incinerators under 40 CFRZ64.343(c).

Moreover, the oxygen level to whichCO values are corrected is notsignificant since the CO levels for allfacilities are corrected to a commonbasis. If the oxygen correction levelwere changed from 7% to some othervalue, then theoretically, the CO limitwould have to be adjusted accordingly,and the effect on individual facilitieswould remain the same.

b. Implementation of the 100 ppmv COLimit. The procedures used to implementthe 100 ppmv CO limit are discussedbelow, including oxygen and moisturecorrection, format of the limit, andcompliance with the limit.

Oxygen and Moisture Correction. TheCO limit under Tier I (and Tier II) is on adry gas basis corrected to 7 percentoxygen. The oxygen correctionnormalizes the CO data to a commonbase, accounting for the variation indesign and operation of the various

combustion devices. In-system leakage,facility size, and waste feed type areother factors that cause oxygenconcentrations to vary widely in fluegases and were considered in selectionof the oxygen correction factor. Thecorrection for moisture normalizes theCO data that results from the differenttypes of CO monitors used at facilities(e.g., extractive, in situ, etc.). EPA'sevaluation indicates that application ofthe oxygen and moisture corrections canchange measured CO levels by a factorof two In some cases.

Measured CO levels must becorrected continuously for the amount ofoxygen in the stack gas according to theformula:CO,=COmx14/(E-Y)Where:

CO. is the corrected concentration of CO inthe stack gas, CO, is the measured COconcentration according to guidelinesspecified in Methods Manual forCompliance with the BIF Regulations(Methods Manual) 22, E is the percentageof oxygen contained in the air used forcombustion, and Y is the measuredoxygen concentration on a dry basis inthe stack. Oxygen must be measured atthe same stack location at which CO ismeasured under procedures that are alsoprovided in the Methods Manual.

Format of the CO Limit. EPAproposed that the CO limits beimplemented under either of twoalternative formats, the hourly rollingaverage format or the time-above-a-limitformat. Under this approach, applicantswould select the preferred approach ona case-by-case basis. Comments werereceived in support of both alternativeformats. Based on further evaluation ofthe two formats and for reasonsexplained below, EPA is requiring use ofthe hourly rolling average format forcompliance with this rule.

Under the hourly rolling averageformat, a facility must measure andrecord CO levels as an hourly rollingaverage. This approach allowsinstantaneous CO peaks withoutrequiring a cutoff provided that at othertimes during the previous hour COlevels were correspondingly below thelimit. This approach requires a COmonitoring system that can continuouslymeasure and adjust the oxygencorrection factor and compute thehourly rolling averages.

Under the proposed time-above-a-limit format, dual CO limits would beestablished in the permit: the first as anever-to-exceed limit and the second as

21 U.S. EPA. Methods Manualfor Compliancewith the BF Regulations, December 1990. Availablefrom the National Information Service NTIS), 5285Port Royal Road, Springfield, VA 22181. (703) 487-4600. The document number is PB 91-120-00.

a lower limit for cumulativeexceedances of no more than a specifiedperiod of time in an hour. These limitsand the time duration of theexceedances would be established on acase-by-case basis by equating the massemissions (peak areas) in both theformats (time-above-a-limit and hourlyrolling average formats] so that theregulation would be equally stringent inboth cases. The instruments needed forthe time-above-a-limit format wouldinclude a CO monitor, a recorder, and atimer that could indicate the cumulativetime of exceedances in every clock hour,at the end of which it would berecalibrated (manually orelectronically). Oxygen would not bemeasured continuously in this format;instead an oxygen correction factorwould be determined from operatingdata collected during the trial burn.Subsequently, oxygen correction factorswould be determined annually or atmore frequent intervals specified in thefacility permit.

EPA has re-examined the time-above-the-limit format in light of severalcomments received and has decided todelete this alternative in today's finalrule because:

1. Since a facility would not be required tomeasure oxygen continuously under thisformat, there would be no assurance that afacility would be operated reasonably closeto the oxygen level at which it operatedduring the trial burn. Even with a dailydetermination of an oxygen correction factor,there would be the possibility of "gaming" bythe facility (operating the facility at lowoxygen levels during the short test periodwhen the oxygen is measured, getting afavorable correction factor established on thebasis, and thereafter letting the facilityoperate at high oxygen levels). Since themajor advantage of this format was thecheaper cost due to the omission of theoxygen monitoring requirement. addingcontinuous oxygen monitoring to this formatwould remove this advantage as well; and

2. The proposed computations forconverting hourly rolling averages to thisformat would be cumbersome, inexact, andabove all, very restrictive. To obtain aconservative conversion, a permit writerwould have to assume that CO levels willremain at the established never-to-exceedlimit for the full specified time in the hour,and at the lower established limit the rest ofthe time. The CO limits obtained by thesecomputations would be very restrictive. Asan example, a conversion of a Tier I limit of100 ppmv hourly rolling average for a facilityhaving a single CO excursion of 4-minutesduration in which the peak level was 1,000ppmv, would result in a permit specifying thatfor the remaining 56 minutes, CO could notexceed 34 ppmv, a very restrictive limit. Forexample, a CO profile of 30 ppmv for 55minutes and 40 ppmv for the remaining 5minutes would result in a violation.




Compliance with the Tier I CO Limit.The Agency considered a number ofalternative approaches for evaluatingCO readings during trial bums todetermine compliance with the 100ppmv limit, including: (1) The time-weighted average (or the average of thehourly rolling averages); (2) the averageof the highest hourly rolling averages forall trial burn runs; or (3) the highesthourly rolling average. The time-weighted average alternative providesthe lowest CO level that couldreasonably be used to determinecompliance, and the highest hourlyrolling average alternative provides thehighest CO level that could reasonablybe used. EPA is requiring the use of themost conservative of these approaches,the highest hourly rolling averageapproach, for interpreting trial burn COemissions for compliance with the 100ppmv Tier I limit. (This approach isconservative because trial burn COlevels are compared to the maximumCO allowed under Tier 1-100 ppmv.)EPA believes this conservativeapproach is reasonable sincecompliance with the Tier I CO limitallows applicants to avoid the Tier IIrequirement of evaluating HC emissionsto provide the additional assurance (orconfirmation) that HC emissions do notexceed levels representative of goodoperating practice.

3. Tier II PIC Controls: Limits on CO andHC

a. Need for Tier II PIC Controls.Commenters indicated that severaltypes of boilers and many cement kilnswill not be able to meet the (Tier I) 100ppmv CO limit proposed in May 1987even though HC concentrations will notbe high at elevated CO levels. Forexample, boilers that bum residual oil orcoal typically operate with CO emissionlevels above the Tier 1100 ppmv COlimit because of inherent fuelcombustion characteristics, equipmentdesign constraints, routine transientcombustion-related events, requirementsfor multiple fuel flexibility, andrequirements for compliance with NO.emission standards established underthe Clean Air Act. Attempts to reduceCO emissions from these devices tomeet the Tier I limit could proveunsuccessful. In addition, there is apossibility that thermal efficiency couldbe adversely affected if these attemptsare successful.

Similarly. industry and trade groupsfor the cement industry voiced strongopposition to the 100 ppmv CO limit forcement kilns. These commentersindicated that some cement kilns,especially modern precalciners,routinely emit CO above the Tier 1 100

ppmv limit. In general, commentersindicated that while the Tier I limit maybe appropriate for combustion devicesin which only fuel (fossil or hazardouswaste) enters the combustion chamber,it is inappropriate for cement kilns andother product kilns in which massiveamounts of feedstocks are processed.These feedstocks can generate largequantities of CO emissions which areunrelated to the combustion efficiencyof burning the waste and fuel. Whereasall the CO from boilers and someindustrial furnaces is combustion-generated, the bulk of the CO fromproduct kilns can be the result ofprocess events unrelated to thecombustion conditions at the burnerwhere wastes are introduced.2 3

Therefore, limiting CO emissions fromthese combustion devices to the Tier I100 ppmv level may be difficult and maynot be warranted as a means ofminimizing risk from PICs.

In summary, commenters argued thatthese are specific instances and classesof combustion devices for which theTier I CO limit would be difficult orvirtually impossible to meet, and thusthis limit is inappropriate since EPA hasnot established a direct correlationbetween CO emissions, PIC emissions,and health risks.

In light of these concerns, commenterssuggested that EPA establish CO limitsfor specific categories of combustiondevices based on CO levels achieved byunits operating under best operatingpractices (BOP). The Agency consideredthis approach but determined thatequipment-specific CO trigger limitswould be difficult to establish andsupport and would not necessarilyprovide adequate protection from PICemissions. Nonetheless, EPA believesthat the CO limits should be flexible toavoid major economic impacts on theregulated community since no directcorrelation has been establishedbetween exceeding the 100 ppmv COlimit and increasing health risks fromPIC emissions. EPA believes, however,that at some elevated CO level PICemissions would pose significant risk.At this time, EPA is unable to identify aprecise CO trigger level since the triggerlevel may vary by the type and design ofthe combustion device and the fuel mixused in the device. Consequently, EPAhas established a two-tiered approach tocontrol PICs. Under Tier I, CO is limitedto 100 ppmv or less, as discussed above.Under Tier II, CO levels can exceed 100

12 For example, CO can be generated from thetrace levels of organic matter contained in the rawmaterials as the materials move down the kiln fromthe "cold" feed end to the "hot" end where the fueland waste is fired and the product is discharged.

ppmv provided that the owner oroperator demonstrate that the HCconcentration in the stack gas does notexceed a good operating practice-basedlimit of 20 ppmv (except that theDirector may establish under§ 266.104(f) an alternative HC limit forfurnaces that feed raw materialcontaining organic matter and, thus,cannot meet the 20 ppmv limit).

Under Tier II, the CO limit for afacility is based on the levels achievedduring a successful compliance test. TheAgency originally proposed twoalternative approaches for establishingHC emission limits under the Tier IIwaiver: a health-based approach and atechnology-based approach. These twoalternatives and EPA's rationale forselecting the technology-based approachfor the final rule are discussed below.Before moving to those discussions,however, it may be useful to summarizethe conclusions of an evaluation byEPA's Science Advisory Board of theproposed PIC controls.

b. Comments by EPA's ScienceAdvisory Board (SAB). We presentbelow a summary of SAB'sconclusions 24 on the scientific supportfor EPA's proposed PIC controls andEPA's response:• SAB: The Agency has not

documented that PICs from hazardouswaste combustion can cause significanthealth risk to human health or theenvironment.-EPA Response: While the Agency

agrees that available data do notshow that PICs are likely to pose asignificant health risk, EPA'semissions testing to date has beenable to identify and quantify only asmuch as 60% of the organiccompounds being emitted during anytest. During many of EPA's tests, lessthan 5 to 10% of organic emissionswere characterized. The Agency isconcerned that this large fraction ofuncharacterized organic emissionscould be comprised of compounds thatcan pose significant health risk.Therefore, the Agency believes thatPICs have the potential to present ahazard and should be controlled.• SAB: It is prudent to control PICs

given the inability to show that they donot pose a health risk because oflimitations of sampling and analyticaltechniques and health andenvironmental impact assessment dataand methodologies.

04 U.S. EPA. "Report of the Products ofIncomplete Combustion Subcommittee of theScience Advisory Board", Report #EPA-SAB--EC-90-004, January 1990.

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-EPA Response: The Agency agrees.Additional emissions testing cannotbe used to determine if, in fact, PICscan pose significant risk because thesampling and analytical techniquesare not available to identify theunknown compounds. Moreover, evenif the techniques were available,health effects data are not likely to beavailable for the compounds so that arisk assessment could not beconducted.0 SAB: The use of CO and HC to

ensure high combustion efficiency seemsto be a reasonable approach to controlPIC emissions.

* EPA Response: The Agency agrees.* SAB: Under the Tier H controls

when CO exceeds 100 ppmv, HC shouldbe monitored continuously.-EPA Response: The Agency agrees.

Today's final rule requires continuousHC monitoring under the Tier IIcontrols (see § 266.104(c)) when COlevels exceed 100 ppmv, and forcertain industrial furnacesirrespective of CO level (see§ § 266.104(d) for permit furnaces and266.103(a)(5) for furnaces operatingunder interim status).* SAB: There is no scientific support

for the health-based approach toestablish HC limits on a site-specificbasis based on a calculated "unit risk"value for total HC and stack gasmonitoring of HC concentrations.-EPA Response: The final rule does not

allow the use of the proposed health-based approach to control HC. HC arecontrolled under the technology-basedlimit of 20 ppmv. See § 266.104(c).* SAB: The risk assessment

procedures are adequate, however, toshow that the technology-based HClimit of 20 ppmv appears to beprotective of human health.-EPA Response: The Agency agrees.

* SAB: The agency should show thatthe proposed limits for CO and HC donot result in frequent automatic wastefeed cutoffs that may increase PICemissions.-EPA Response: See discussion in

section B.2.a above.Thus, the SAB supported the overall

reasonableness of the course adopted inthis rule to control potential risks fromemissions of PICs.

c. Health-Based Approach for HCLimits. Under the Tier II health-basedapproach, the Agency proposed to allowapplicants to demonstrate that PICemissions from combustion devices posean acceptable risk (i.e., less that 10-9) tothe maximum exposed individual (MEI).Under this approach. EPA proposed torequire that applicants quantify HCemissions during trail burns and assume

that all hydrocarbons are carcinogeniccompounds with a unit risk value thatwould be calculated based on availabledata. The HC unit risk value would be1.0x 10-5 m3/ug and would represent theadjusted 95th percentile weighted (i.e.,by emission concentration) average unitrisk of all the hydrocarbon emissiondata in EPA's database of field testing ofboilers, industrial furnaces, andincinerators burning hazardous waste.The weighted unit risk value for HCconsiders emissions data forcarcinogenic PICs (e.g., chlorinateddioxins and furans, benzene, chloroform,and, carbon tetrachloride) as well asdata for PICs that are not suspectedcarcinogens and are considered to berelatively nontoxic (e.g., methane, andother C1 as well as C2 hydrocarbons.2 5

The Agency proposed to implementthis provision by back-calculating anacceptable HC emission rate (and,based on stack gas flow rates, a HCconcentration) from the acceptableambient level based on the calculated"total HC" unit risk value discussedabove and allowing an incrementalcancer risk of I in 100,000.

A number of commenters supportedthe health-based approach while severalothers pointed out that the approachwas seriously flawed. EPA's ScienceAdvisory Board reviewed the approachas discussed above and concluded thatthe site-specific, health-based approachof controlling HC was not scientificallysupportable.

Upon re-evaluation, EPA believes thatbasing the HC limit on a health-basedapproach is not supportable and, thus,has not selected this approach for thefinal rule. Given the limited data baseon the types and concentrations of PICsemitted over a range of operatingconditions, we are concerned that, thepotency value that the proposedapproach would apply to the total massof hydrocarbons emitted may not beappropriate. It is not clear whether theproposed potency value may overstateor understate the risk posed by HCemissions. In addition, we areconcerned that we do not fullyunderstand what types of hydrocarbonemissions are actually detected by thecontinuous monitoring equipment. Forexample, as we discussed at proposal,certain halogenated compounds areunder reported by the HC detectionsystem. Finally, as we noted at proposal,the proposed risk-based approach couldallow extremely high HC

"6 Additional information on the development ofthe unit risk factor can be found in U.S. EPA,Background Information Document for theDevelopment of Regulations for PIC Emissions fromHazardous Waste Incinerators. October 1969.

concentrations--concentrations clearlyindicated of combustion upsetconditions.

d. Technology-Based Approach: 20ppmv HC Limit. Under the technology-based approach, the Tier I CO limit of100 ppmv will not have to be met if HClevels in the stack gas do not exceed agood operating practice-based limit of 20ppmv 2 8 (measured on an hourly rollingaverage basis, reported as propane, drycorrected to 7% oxygen). As notedabove, EPA developed this technology-based approach because of currentscientific concerns (seconded by theSAB) related to a health-basedapproach. In addition, the health-basedapproach could allow HC levels ofseveral hundred ppmv, levels that areclearly indicative of "upset" combustionconditions. The approach, as notedabove, lacks a firm scientific basis andcould allow facilities to operate underupset conditions. EPA would notauthorize such operations unlessreasonably certain they would not posea significant risk to human health andthe environment. Such reasonablecertainty does not exist here.

One commenter agreed that the PICstandard should be protective withoutimposing a technology "fix." AlthoughEPA believes the development of ahealth-based approach is a step in theright direction, the Agency is concernedabout whether the health-based Tier IIapproach is adequately protective giventhe limited database on PIC emissionsand the uncertainty as to what fractionof organic emissions would be detectedby the HC monitoring system. Despitethe limitations of the HC health riskassessment methodology, EPA believes(and the SAB concurs) it is reasonableto use this methodology to predictwhether a technology-based limitappears to be protective. Accordingly,EPA used the health risk assessmentmethodology to show that a 20 ppmv HClimit would not result in an incrementallifetime cancer risk to the hypotheticalmaximum exposed individual greaterthan 1 in 100,000.

The final rule establishes limits forboth GO and HC under the Tier II PICcontrols. The CO limit is established asthe average over all runs of the highesthourly rolling average for each run ofthe compliance test or trial burn. Todemonstrate compliance with the HClimit, the highest hourly rolling averageHC level during the compliance test or

28 As discussed at proposal the 20 ppmv limitrepresents a demarcation between good and poorcombustion conditions based on HC emissions datafrom 24 facilities. The 20 ppmv limit is not based onbest operating practice. A best operating practicelimit would be set a level on the order of 5 ppmv.



Federal Register / VoL 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations 5

trial burn cannot exceed 20 ppmv(except as otherwise provided forfurnaces feeding raw materialscontaining organic matter, reported aspropane, corrected to 7% oxygen on adry basis.

The Agency considered whether toestablish provision for a case-by-casewaiver of the 20 ppmv HC limit basedeither on health-risk assessment ortechnical feasibility (i.e., feasibility ofproviding combustion conditions tominimize fuel-generated HC). The finalrule does not provide for a waiver of the20 ppmv HC limit as an indicator ofgood combustion conditions andminimum fuel-generated PIC emissions.(The final rule does, however, allow theDirector to establish under the part Bpermit proceedings an alternative HClimit for industrial furnaces (e.g., cementkilns, light-weight aggregate kilns) toaccount for hydrocarbons that areemitted from trace levels of organicmatter in the raw material. Anyalternative HC limit established for afurnace will ensure that fuel-generatedhydrocarbons (hazardous waste andother fuels) are less than 20 ppmv byestablishing the HC limit based on HCconcentrations when the system isdesigned and operated under goodcombustion conditions without burninghazardous waste.2 7 See section 1I.B.5 ofPart Three of this preamble for morediscussion of the alternative HC limit forindustrial furnaces.)

EPA did not provide a waiver of theHC limit in the final rule because: (1)The Agency believes, and SAB concurs,that a site-specific, health riskassessment approach to establishing HClimits (e.g., a waiver of the 20 ppmvlimit) is not scientifically supportable;and (2) a technology-based waiver is notsupportable because well-designed andoperated hazardous waste combustiondevices can readily meet a 20 ppmv HClimit.

Several commenters disagreed withEPA that both CO and HC should bemonitored, stating that it is unnecessaryto monitor CO if HC is monitored. TheAgency continues to believe that it isreasonable to require both CO and HCmonitoring when CO levels exceed 100ppmv. When CO levels exceed the Tier Ilevel, the facility is not operating at highcombustion efficiency and the potentialfor high PIC emissions exists. TheAgency believes that, since COmonitoring is a widely practiced

27 We note that this approach should limit fuel-generated hydrocarbon concentrations to wellbelow 20 ppmv because fuel-generatedhydrocarbons from a welt-designed and operatedcement or light-weight aggregate kiln should notexceed 5 ppmv.

approach for improving and monitoringcombustion efficiency, and since COemission levels may respond morequickly to process upsets than HClevels, the apparent redundancy inrequiring both CO and HC monitoring iswarranted to ensure protection ofhuman health.

Another commenter added that HCmonitoring could be supplemented byfrequent testing for common PICs thatrespond poorly to HC monitors, such ascarbon tetrachloride, formaldehyde,perchlorethylene, and chlorobenzene. Atthis time, the Agency believes thatcontinuous HC monitoring combinedwith CO monitoring is adequate in mostcases to detect when the facility isoperating under combustion upsetconditions (this is another reason,however, that monitoring both CO andHC is reasonable when CO levelsexceed the level normally indicative ofgood combustion-100 ppmv). We notethat, as discussed in section II.D belowthe final rule requires a hot HCmonitoring system (i.e., unconditionedgas sample heated to a minimum of 150°C) which ensures minimum loss oforganic compounds. Nonetheless, theAgency is currently developing samplingand analytical techniques tocontinuously monitor indicator organiccompounds such as those suggested bythe commenter.

e. Basis for Final Rule. EPA believesthat the 20 ppmv HC limit in the finalrule for the Tier II PIC controls isrepresentative of an HC limit thatdistinguishes between good and poorcombustion conditions. (When a facilityoperates under poor combustionconditions, PIC emissions can increaseand may result in adverse health effectsto exposed individuals.) This HC limit iswithin the range of values reported inthe Agency's data base for hazardouswaste incinerators, boilers, andindustrial furnaces that burn hazardouswaste, and the limit is also protective ofhuman health based on risk assessmentsconducted for 30 incinerators. See 54 FR43723. Under Tier II, HC must bemonitored continuously, recorded on anhourly rolling average basis, reported asppmv propane, and corrected to 7percent oxygen on a dry basis. Inaddition, CO must be monitoredcontinuously, corrected to 7 percentoxygen on a dry basis, recorded on anhourly rolling average basis, and maynot exceed the limit established duringthe test burn (i.e., the average over allruns of the highest hourly rollingaverage for each run).

4. Special Requirements for FurnacesThe final rule provides several special

requirements for industrial furnaces

stemming from the fact that: f1) Someindustrial furnaces, notably cementkilns, are not able to meet the 20 ppmvHC limit because trace levels of organicmatter in raw materials can emitsubstantial levels of hydrocarbons; and(2) the PIC controls may not beprotective for furnaces (e.g., cementkilns and mineral wool cupolas) thatfeed hazardous waste at locations otherthan where normal fuels are fired. Thesespecial requirements are discusscdbelow.

a. Alternative HC Limit. EPArequested comment on whetheralternative HC limits may beappropriate for certain industrialfurnaces. See 54 FR 43724 (Oct. 26, 1989)A number of commenters 28 requestedthat EPA allow cement kilns, light-weight aggregate kilns, and lime kilnsthat cannot meet the 20 ppmv HC limitbecause of the hydrocarbons generatedby trace levels of organic materials inthe normal raw materials to establish asite-specific alternative HC limit thatdoes not allow HC levels when burninghazardous waste to be significantlyhigher than when burning normal fuels,processing normal raw materials, andproducing normal products in a systemthat is designed and operated tominimize hydrocarbon concentrations instack gas. Nineteen commenters pointedout that baseline HC emission levelsfrom cement kilns can be attributed tothe naturally-occurring raw materialsthat are used in the production ofcement. Use of shale as a raw material,for example, can result in HC emissionsfrom kerogens in the shale. Use of flyash as a source of iron and silica couldresult in increased CO emissions frompartial oxidation of free carbon in the flyash. Commenters claim thatapproximately 6 to 10 cement plantsmay not be able to comply with the HClimit of 20 ppmv even though theygenerate minimal HC from sources otherthan raw materials (e.g., hazardouswaste fuels, other fuels, organiccompounds in slurry water). The organiccompounds in normal raw materialswould not ordinarily be hazardous, sothat their emissions (e.g., throughvolatilization) would not raise the typesof concerns normally addressed byRCRA. "9

28 In addition to comments on the October 26,1989 supplement to the proposed rule, see mnutesof the EPA meetings with the Cement Kiln RecyclingCoalition of April 17, 1990; May 23,1990, June 4,1990;, June 20,1990 July 19. 1990; and October It),1990. See also minutes of the EPA meeting withSouthdown, Inc. on May 11, 1990, and the letter fromthe Cement Kiln Recycling Coalition to BobHolloway, EPA, dated June 15, 1990.

29 We note, however, that nonhazardous organicconstituents in feedstreams may be partially

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The Agency believes that it will bepossible in some situations to developan approach on a case-by-case basis toeffectively implement an alternative HClimit under the principle stated above.(If the 20 ppmv HC limit were health-based, the Agency would be morereluctant to develop an alternative to it.Given, however, that the limit is ameasure of combustion efficiency, theAgency believes it reasonable todevelop an alternative means for thisclass of furnaces to demonstratecombustion efficiency.) The Agencyconsidered a number of approaches toestablishan alternative HC level anddetermined in the time available thatnone appeared to be workable in allsituations. The Agency is thereforeadopting a more individualizedapproach in the present rule that allowspermit writers to establish analternative HC limit (i.e., a HC limit thatexceeds 20 ppmv) in a facility'soperating permit, and allows permitwriters to grant an extension of time tocomply with the HC limit during interimstatus, based on the following showings:(1) For cement kilns, the kiln is notequipped with a by-pass duct that meetsthe requirements of § 266.104(f)(1); (2)the applicant demonstrates that thefacility is designed and operated tominimize hydrocarbon emissions fromfuels and raw materials; (3) theapplicant develops an approach toeffectively monitor over time changes inthe operation of the facility that couldreduce baseline HC levels-for example,changes in raw materials, fuels, oroperating conditions-which couldresult in establishing a new baselineand corresponding adjustment of the HClimit; and (4) the applicant demonstratesthat the hydrocarbon emissions are notlikely to pose a significant health risk.See § 266.104(f)(2). We explain theseprovisions in more detail below, alongwith an explanation of which provisionsapply during interim status and whichare part of permit application andissuance.

Interim Status Facilities. Today's rulerequires facilities operating in interimstatus to comply with CO and, ifrequired, a 20 ppmv HC limit within 18months of the rule's date ofpromulgation. The rule provides for acase-by-case extension from theserequirements (as well as the particulate,metals, and HCI/CI2 standards) "ifcompliance is not practicable forreasons beyond the control of the owneror operator." See § 266.103(c)(7)(ii). Thesituation where a furnace may be

combusted to form hazardous products ofincomplete combustion.

unable to achieve the 20 ppmv HC limitbecause of organics present at baselineconditions (i.e., when the facility isdesigned and operated to minimize HCemissions from raw materials and fuelswhile producing normal products undernormal operating conditions and whenno hazardous waste is burned) may beeligible for the extension of timeprovided the following conditions aresatisfied:

1. The applicant for the extension of timemust have submitted a complete part Bpermit application. The application mustinclude the following information pertinent tothe question of an alternative HC limit: (a).Documentation that the system is designedand operated to minimize HC emissions fromall sources when the baseline level isestablished and when hazardous waste isburned; (b) documentation of the baseline HCflue gas concentrations when the facility isoperated to minimize HC emissions andwhen feeding normal raw materials andnormal fuels to produce normal productsunder normal operating conditions and whennot burning hazardous waste: (c) a testprotocol to confirm the baseline HC (and CO)level; (d) a trial burn protocol to demonstratethat, when hazardous waste is burned, HC(and CO) concentrations do not exceed thebaseline level; and (e) a procedure to show ifand when HC emissions from nonhazardouswaste sources may decrease (in which case,the overall HC limit might be adjusteddownward after a new baseline isestablished). See § 270.22(b). (Thesubstantive basis for these requirements isexplained in more detail below.)

2. During interim status, the applicant mustnot only conduct emissions testing when 'burning hazardous to certify compliance withall remaining emissions controls-dioxinsand furans, PM. metals, and HCl/CG2-butalso establish and comply with interim limitson CO and HC presented in the part B permitapplication as levels the applicant hasdetermined by testing (without burninghazardous waste) are baseline levels. Wenote that the Director may not have timeduring the review of the extension request(and a preliminary review of the part Bapplication) to confirm the adequacy of theinterim CO and HC limits proposed by theapplicant. Moreover, to do so would requirethe types of oversight of test protocols,emissions testing, and review of data thatwill be applied under the permit process.Thus, the interim limits are subject torevision based on (confirmation) testing insupport of the operating permit. Nonetheless,EPA believes that establishing interim COand HC limits and requiring the owner/operator to comply with them until a permitis issued (or denied) is reasonable andprovides a measure of protection of humanhealth and the environment.

It should be noted that the Agency does notbelieve that it is possible to establish analternative HC limit during interim status.This is because the level of interactionbetween an applicant and permit writer overevaluation of the various protocols toestablish a HC baseline And determine when

it should be reduced, plus conducting testburns to confirm the HC baseline and thatHC levels do not increase when hazardouswaste is burned, plus conducting a health-risk assessment for organic emissions when'hazardous waste is burned are beyond thescope of interim status. Consequently, therule is structured so that the alternative HClimit (if warranted) would be established aspart of the permit, and the interim statuscertification of compliance deadline can beextended, if the Director finds this iswarranted, while the permit is beingprocessed. The Director may also make theextension of time conditional on the timeestimated to process the permit application orother factors, and can be conditioned onoperating conditions than ensure the facilitywill operate in a manner that protects humanhealth and the environment. Any suchcondition would be embodied in an interimstatus extension determination that isenforceable as a requirement of subtitle C(much as conditions in a closure plan areenforceable), and would be documented in anadministrative record for the determination.

3. Cement kilns with a by-pass ductmeeting the requirements of J 266.104(g)(2)are ineligible for an extension. The ruleprecludes cement kilns operating with a by-pass duct from eligibility for the extension ofthe certification of compliance date forcompliance with the CO and HC limit, as wellas for obtaining an alternative HC limit in apermit.

Fully Permitted Facilities. TheDirector may establish an alternativeHC limit in the facility's operatingpermit provided that the applicant meetsthe -following requirements. Informationand data documenting compliance withthese requirements must be included inthe part B permit application. See§ 270.22(b). First, the applicant mustdocument in the permit application thatfacility is designed and operated tominimize HC emissions from all sources,including raw materials and fuels.Examples of situations where thesystem is not designed and operated tominimize HC (and CO) levels duringbaseline testing are when: (1) Coal ismixed with raw material which is fedinto a cement kiln preheater such thatthe coal can contribute to HC emissions;(2) cement kiln slurry water containsenough organic compounds tosignificantly contribute to HC emissions;(3) waste fuels such as tires are burnedin a manner that could contribute to HCemissions; (4) the furnace is notoperated and designed to minimizeemissions of hydrocabons emitted fromraw material (in general, the morequickly the raw material is exposed toelevated temperatures, the lower thehydrocarbon emissions); and (5) normalfuels are not burned under goodcombustion conditions.

Second, the applicant must propose inthe permit application baseline flue gas




CO and HC levels. These proposedbaseline levels also serve as interimvalues under which the facility mustcperate under a conditional timeextension for certification of compliancewith the HC standard until permitissuance (or denial]. The proposedbaseline levels must be supported byemissions testing under baselineconditions (ie., when the facility isdesigned and operated to minimize HCemissions from raw materials and fuelswhile producing normal products undernormal operating conditions and whenno hazardous waste is burned. Baselinelevels must be determined from testdata as the average over all valid runsof the highest hourly rolling averagevalue for each run. This is the sameapproach specified by the rule todetermine limits on other operatingparameters (e.g., maximum feed ratelimits, maximum temperatures, etc). EPAbelieves that this approach is workablefor cement kilns so given thatcommenters have asserted that whenhazardous waste is burned,hydrocarbon levels do not increase andoften decrease. As discussed in sectionII.E of Part Three of the preamble, HClevels from a cement kiln with HC levelsof 66 to 70 ppmv when burning coaldecreased to 38 to 83 ppmv whenburning hazardous waste fuel. If thefacility cannot install continuousmonitors for HC (and CO and oxygen] intime to conduct these baseline testsprior to submittal of the permitapplication (which must be sufficientlyprior to 18 months after promulgation ofthe rule to give the Director time toconsider whether to grant the timeextension), the facility may use portablemonitors. We note that the HCmonitoring system must be a hot,unconditioned system. In addition, wenote that different baseline values maybe necessary for different modes ofoperation if the baseline HC (or CO)level changes significantly under thosemodes of operation. Examples are whenthe raw material mix is changed to makea different cement product or whendifferent fuels are burned.

Third, the applicant must developemissions testing protocols to: (1)Confirm the baseline HC and CO levelsproposed in the permit application (andunder which the facility must operate ininterim status upon receipt of anextension of time to comply with the HClimit and until an operating permit is

s0 Although any industrial furnace that cannotmeet the 20 ppmv HC limit because of organicmatter in raw material is eligible to apply for analternative HC bruit, only one commenter expressedconcern that industrial furnaces other than cementkilns may not be able to meet the 20 ppmv HC limit.

issued (or denied)); and (2) todemonstrate that, when hazardouswaste is burned, HC and CO levels donot exceed baseline levels (andemissions of other pollutants do notexceed allowable levels). If a baselineHC or CO level is to be established formore than one mode of operation, abaseline confirmation test (comprised ofat least three valid runs) must be run foreach mode.

Fourth, the applicant must develop anapproach to effectively monitor overtime changes in the operation of thefacility that could significantly reducebaseline HC or CO levels. If baselinelevels are significantly reduced, then thealternative HC and CO limits that applywhen burning hazardous waste mustalso be reduced. Such changes couldinclude: (1) Changes in theconcentration of organic matter in rawmaterials; (2) changes in theconcentration of organic matter in theraw material mix due to changes in themixture of raw materials needed toproduce different types of product: (3)changes in fuels; and (4) changes in theconcentration of organic compounds inslurry water used for a wet cement kiln.The approach must be workable andenforceable.

EPA is requiring this condition inorder to avoid establishing a highbaseline which is then reduced withoutalso lowering the HC limit, potentiallyallowing the hazardous waste to beburned under poor combustionconditions creating high, but undetected,HC levels (i.e., hazardous waste couldbe burned under poor combustionconditions and could be emitting highHC levels even though the HC limit wasnot exceeded). (The Agency notes thatthe problem of establishing a HCbaseline and for determining when thebaseline might change for this type ofindustrial furnace is more difficult thandetermining when the raw materialbaseline changes in documenting whenco-combustion of hazardous waste withraw materials in a Bevill device mightaffect the composition of residues. Seesection XIII of Part Three of thepreamble. This is because, in the case ofthe HC baseline, not only must the rawmaterials' and fuels' composition bemonitored, but the units design andoperating conditions as well todetermine whether the baseline haschanged. Thus, the rule provides formore interaction in establishing baselineconditions and determining when theychange for assessing alternative HClimits for cement kilns than it does whenmaking determinations as to whether co-combustion of hazardous waste can

remove residues from eligibility forexclusion under the Bevill amendment.)

Finally, EPA is concerned thathazardous waste burning may affect thetype and concentration of organiccompounds emitted from an industrialfurnace that has elevated HCconcentrations attributable to rawmaterials. For example, the chlorine inthe hazardous waste may result inhigher concentrations of chlorinatedorganic compounds. Therefore, the rulerequires the owner or operator, as partof the permitting process, to use state-of-the-art emissions testing procedures andrisk assessment to demonstrate thatorganic emissions are not likely to poseunacceptable health risk. The owner oroperator must conduct emissions testingduring the trial burn to identify andquantify the organic compounds listed inappendix VIII, part 261, that may beemitted using test procedures specifiedby the Director on a case-by-case basis.As noted above, although EPA does notbelieve such risk-based approaches tobe adequate as the basis for a nationalrisk-based PIC standard, we think theapproach is part of the best means ofassuring that cement kilns combusthazardous waste fuels properly in thoseinstances where HC levels are greaterthan 20 ppmv as a result of organics innormal raw material feed.

Two sampling and analysisapproaches that the Director may useare discussed below. One protocolinvolves the following steps to identifyand quantify concentrations of organiccompounds in stack emissions:

1. Sample volatile organic compounds usingthe VOST train of Method 0030 as prescribedin SW-846. Analytical work is conductedusing GC/MS according to Method 5040 inSW-848.

2. Sample semi-volatile organic compoundsusing the sampling train prescribed inMethod 0010 in SW-848. Analytical work isconducted using GC/MS according to Method8270 in SW-84.

3. Sample aldehydes and ketones using animpinger train with 2-4-di-nitro-phenylhydrazine. (2-4-DNPH in the impingersolution as prescribed in Method 0011 in theMethods Manual, and analysis of impingersolution by high performance liquidchromatography [HPLC) as specified in"Analysis for Aldehydes and Ketones byHigh Performance Liquid Chromatography" inthe Methods Manual.

Another protocol is a screeningapproach that has been described in theliterature 31 that uses the followingprotocols as specified in SW-846:s1

3 1Johnson, Larry, et al, "Screening Approach forPrincipal Organic Hazardous Constituents andProducts of Incomplete Combustion". JAPCAJournal, Volume 39, No. 5, May 1989.

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1. Soxhlet extraction samplepreparation;

2. Gas chromatography (GC) coupledwith flame ionization detector (FID) ormass spectrography (MS) screening;

3. Total chromatographic organics(TCO) and gravimetric (GRAV)procedures; and

4. High performance liquidchromatography-ultraviolet/MS (HPLC-UV/MS) screening and compoundidentification.

To select an appropriate protocol, theDirector will consider the state-of-the-art of sampling and analyticaltechniques and the expected nature oforganic emissions considering emissionsdata or other information.

We note that, under this PIC riskassessment, emission rates must also bedetermined for the 2,3,7,8-chlorinatedtetra-octa congeners of chlorinateddibenzo-p-dioxins and dibenzofurans(CDDs/CDFs) using Method 23,"Determination of PolychlorinatedDibenzo-p-Dloxins and PolychlorinatedDibenzofurans (PCDFs) from StationarySources" in Methods Manual forCompliance with the BIF Regulations(Methods Manual), incorporated intoday's rule as appendix IX of part 266.The risks from these congeners must beestimated using the 2,3,7,8-TCDDtoxicity equivalence factor prescribed in"Procedures for Estimating the ToxicityEquivalence of Chlorinated Dibenzo-p-Dioxin and Dibenzofuran Congeners" inMethods Manual.

The owner or operator must thenconduct dispersion modeling to predictthe maximum annual average groundlevel concentration of each such organiccompound. On-site ground levelconcentrations must be considered if aperson resides on-site; otherwise, onlyoff-site concentrations may beconsidered. Dispersion modeling mustbe conducted in conformance withEPA's Guideline on Air Quality Models,EPA's "Hazardous Waste CombustionAir Quality Screening Procedure"provided in Methods Manual, or EPA'sScreening Procedures for Estimating AirQuality Impact of Stationary Sources.The Methods Manual and the Guidelineon Air Quality Models are incorporatedin today's rule as appendices IX and X,respectively, to part 266. The ScreeningProcedures document is incorporated byreference in § 260.11.

Stack heights exceeding goodengineering practice (GEP, as defined in40 CFR 51.100(ii)) may not be used topredict ground level concentrations. Seesection V.B.1.c of Part Three of thispreamble.

If the owner or operator applies for analternative hydrocarbon limit for morethan one industrial furnace such that

emissions from the furnaces are frommore than one stack, emissions testingmust be conducted on all such stacksand dispersion modeling must consideremissions from all such stacks.

To demonstrate that thenoncarcinogenic organic compoundslisted in appendix IV of the rule do notpose an unacceptable health risk, thepredicted ground level concentrationscannot exceed the levels established inthat appendix.

To demonstrate that the carcinogenicorganic compounds listed in appendix Vof the rule do not pose an unacceptablehealth risk, the sum of the ratios of thepredicted ground level concentrations tothe levels established in the appendixcannot exceed 1.0. This is because theacceptable ambient levels established inappendix V are based on a 10-5 risklevel. To ensure that the summed riskfrom all carcinogenic compounds doesnot exceed 10- 5 (i.e., 1 in 100,000) thesum of the ratios described above mustbe used. (We note that the 2,3,7,8-TCDDtoxicity equivalency factor is to be usedto estimate the risk from 2,3,7,8-chlorinated CDDs/CDFs, and the riskfrom these congeners must be added tothe risk from other PICs to ensure thatthe summed risk does not exceed 1 in100,000.)

To demonstrate that other compoundsfor which the Agency does not haveadequate health effects data to establishan acceptable ambient level are notlikely to pose a health risk, the predictedambient level cannot exceed 0.1 f g/m 3 .This is the 5th percentile lowestreference air concentration for thecompounds listed in appendix IV of therule.

b. Feeding Waste at Locations otherthan the Hot End. If hazardous waste isfed into an industrial furnace atlocations other than the "hot" endwhere the product is normallydischarged and where fuels arenormally fired, the rule requires theowner/operator to monitor HCirrespective of whether CO levels do notexceed the Tier I limit of 100 ppmv andto comply with special restrictionsduring interim status. These provisionsare discussed below.

Mandatory HC Monitoring.3 2 Exceptas indicated below, facilities that fire

2Continuous HC monitoring is required for afurnace if hazardous waste is fired at any locationother than the "hot". product discharge end wherefuels are normally fired irrespective of the CO levelin stack emissions (i.e., irrespective if CO levels arelower than the Tier I limit of 100 ppmv) andirrespective of whether furnace off-gas is passedthrough another combustion chamber.

hazardous waste into an industrialfurnace at locations other than the "hot"end where the product is normallydischarged and where fuels arenormally fired must comply with the HClimit even if CO levels do not exceed theTier I limit of 100 ppmv. See § 266.104(d).This is because the Agency is concernedthat the hazardous waste couldconceivably be fired at a location in amanner such that nonmetal compoundsin the waste may be merely evaporatedor thermally cracked to form pyrolysisby-products rather than completelycombusted. If so, little CO may begenerated by the process and, thus,monitoring CO alone would not ensurethat HC emissions were minimized.

However, if hazardous waste isburned (or processed) solely as aningredient, HC monitoring is notautomatically required becauseemissions of nonmetal compounds arenot of concern. This is because themetals emissions controls will ensurethat metals emissions do not pose ahazard. (The rule establishes therestrictions discussed below because weare concerned that the interim statuscontrols on organic emissions may notbe protective when hazardous waste isfed at locations other than the "hot" endof a furnace.] See discussion in'sectionVII.H of Part Three of this preamble forwhen a waste is considered to beburned solely as an ingredient.33

Interim Status Restrictions. Inaddition to requiring HC monitoringwhen hazardous waste is fed into afurnace at locations other than the "hot"end where the product is discharged andwhere fuels are normally fired, today'srule applies other restrictions tohazardous waste burning during interimstatus. See § 266.103(a)(5). Thehazardous waste may not be fed at anylocation where combustion gastemperatures are less than 1800 *F, andthe owner or operator must demonstratethat adequate oxygen is present tocombust the waste. In addition, forcement kilns, the hazardous waste mustbe fed into the kiln itself. Theserequirements are provided to ensureadequate destruction of the waste giventhat the DRE standard (which requires ademonstration by trial burn that organicconstituents in the waste are destroyed)

33 Regulated entities have indicated that there issubstantial confusion over the terms "use as aningredient" and "material recovery". Under theRCRA hazardous waste regulatory program, EPAconsiders a hazardous waste to be burned orprocessed as an ingredient if it is used to produce aproduct. EPA considers a hazardous waste to beburned or processed for material recovery if one ormore constituents of the waste is recovered as aproduct.




is not applicable during interim status.Like the requirement for mandatory HCmonitoring, however, these restrictionsdo not apply if the hazardous waste isburned (processed) solely as aningredient. For further discussion, seesection VII.H of Part Three of thispreamble.

5. Special Considerations for CementKilns

a. Monitoring in the By-Pass Duct of aCement Kiln. The final rule providesthat cement kilns with by-pass ductsmay monitor CO and, if required, HCconcentrations in the by-pass duct. Mostprecalciner and some preheater kilnsare equipped with by-pass ducts wherea portion (e.g., 5-30%) of the kiln off-gasis diverted to a separate air pollutioncontrol system (APCS) and, sometimes,a separate stack. A portion of the kilngases are so diverted to avoid a build-upof metal salts that can adversely affectthe calcination process. Dust collectedfrom the by-pass APCS is usuallydisposed of while dust collected fromthe main APCS is usually recycled backinto the kiln to make the clinker product.

Several comments were receivedregarding sampling at cement kilns. Fivecommenters suggested that HC (and CO)measurements should be allowed in theby-pass duct rather than in the mainstack because: (1) The by-pass gas isrepresentative of the kiln off-gas; and (2)this approach would preclude theproblem of nonfuel HC emissions fromthe raw material exceeding the 20 ppmvlimit. The raw material would be heatedand partially calcined in the precalcineror preheater and HC from that processwould be emitted from the main stack.The by-pass duct draws the kiln off-gasprior to the precalciner or preheater and,so, would not be affected by thatprocess.

Another commenter specificallysupported monitoring CO (and HC, ifrequired] only in the bypass ductprovided that hazardous waste is fedonly to the kiln and not to the preheateror precalciner.

The Agency conducted testing 34 at acement kiln to gather informationrelevant to the issue of HC monitoring inthe bypass duct for preheater andprecalciner cement kilns. The datashowed that the gases in the bypassduct are representative of thecombustion of waste in the kiln.

Based on this test data and publiccomment, the final rule allows CO and,where required, HC monitoring in thebypass duct of a cement kiln provided

14 U.S. EPA, "Emissions Testing of a PrecalcinerCement Kiln at Louisville, Nebraska", November1990.

that: (1) Hazardous waste is fired onlyinto the kiln (i.e., not at any locationdownstream from the kiln exit relativeto the direction of gas flow); and (2) thebypass duct diverts a minimum of 10% ofkiln off-gas. See § 266.104(g). The 10%diversion requirement is based onengineering judgment that, at this levelof kiln-gas diversion, the bypass gas willbe representative of the kiln off-gas.Industry representatives indicate 35 thatthe bypass duct capacity of mostfacilities actively involved in burninghazardous waste exceeds the 10% limit.

b. Use of Hazardous Waste as SlurryWater for Wet Cement Kilns. Some kilnoperators have inquired as to whatregulatory standards apply, if any, ifhazardous wastes are used as slurrywater. The Agency does not regard thepractice as an excluded form ofrecycling. The Agency has long beenskeptical of claims that hazardouswastes are "recycled" when theysubstitute for very commonly availableand economically marginal types of rawmaterials. In particular, the Agency hasbeen skeptical that liquid hazardouswastes serve as a substitute for water.Cf. 48 FR at 14489 (April 4, 1983). In thecase of hazardous waste used as slurrywater, the hazardous constituents in thewaste are ordinarily unnecessary to theclaimed recycling activity and are beinggotten rid of through the slurryingprocess. Given the possibility ofhazardous levels of air emission is high,the practice certainly can be part of thewaste disposal problem. Consequently,the Agency regards such practice as aform of waste management subject toregulation under today's rule.

EPA considered prohibiting the use ofhazardous waste as slurry water for wetcement kilns because of concern thattoxic organic constituents in the wastecould be volatilized and emitted withoutcomplete combustion. The final ruledoes not prohibit using (or mixing)hazardous waste with slurry waterbecause we believe that the controlsprovided by the rule both during interimstatus and under a RCRA operatingpermit adequately address the hazardthat the practice may pose.

If hazardous waste is fed into anyindustrial furnace during interim statusat a location other than the hot, productdischarge end, combustion gastemperatures must exceed 1800 *F at thepoint of introduction, and the owner oroperator must document that adequateoxygen is present to combust organicconstituents in the waste. See discussionabove. EPA believes that these

33 Letter dated August 16, 1990, from Dr. Michaelvon Seebach, Southdown, Inc., to Dwight Hlustick,EPA.

restrictions will, as a practical matter,preclude use of hazardous waste inslurry water during interim status.

Although these restrictions onhazardous waste burned at locationsother than the hot end of an industrialfurnace do not apply under a RCRAoperating permit, the permit proceedingswill ensure that organic constituents in ahazardous waste that is fed into the kilnin slurry water (or in the slurry itself)will be destroyed. The Director willrequire that toxic nonmetal constituentsin the waste are destroyed to a 99.99%destruction and removal efficiency, andthat adequate oxygen is present tocompletely destroy the organiccompounds.

C. Automatic Waste Feed CutoffRequirements

Today's rule requires that boilers andindustrial furnaces combustinghazardous waste be equipped withautomatic waste feed cutoff systems tolimit emissions of hazardous compoundsduring combustion "upset" situationsand to ensure stable combustionconditions. The automatic waste feedcutoff system must be connected to theCO and HC monitoring system, suchthat an exceedance of a CO or HC limitwould trigger a cutoff of the waste feed.Additionally, the automatic waste feedcutoff system must engage when otherkey operating conditions deviate fromspecified unit operating limits, which aredetermined during compliance testing orwhich are based on manufacturerspecifications. See §§ 266.102(e)(7)(ii)and 266.103(g).

Some commenters disagreed with theproposed automatic waste feed cutoffrequirements. One commenter arguedagainst any waste feed cutoffs for light-weight aggregate kilns. Six commentersexpressed concern that waste feedcutoffs would increase the instability ofthe combustion conditions and wouldpossibly increase air emissions. Threecommenters requested a controlledwaste feed reduction over severalminutes rather than an automatic wastefeed shutoff. Three commenterssuggested different levels of COemissions be set for waste feed cutoffs.

The Agency acknowledges that therecan be performance and other problemsassociated with automatic waste feedcutoffs, and recognizes that they may beundesirable for some applications. Forexample, when the facility operateswithout the use of hazardous waste fuel,use of fossil fuel is increased, and theopportunity is lost for safe disposal ofhazardous waste. Further, HC emissionsmay actually increase if the automaticwaste feed cutoff is triggered frequently

7159




even though combustion chambertemperatures must be maintained whilehazardous waste or residues remain inthe combustion chamber. However, theAgency continues to believe thatautomatic waste feed cutoff systems arenecessary to avoid adverse effect onhuman health and the environment thatcould result if hazardous waste is firedinto the device when it is operatingunder combustion upset conditions.

To address the concerns raised bycommenters, EPA recommendsinstalling pre-alarm systems that alertan owner/operator of potentialproblems and provide time either forcorrective measures to be taken or for astaged cutoff of the hazardous wastefeed. Thus, the use of pre-alarms shouldminimize waste feed cutoffs. In addition,we have included in the rule someadditional requirements related to wastefeed cutoffs and restarts, as discussedbelow.

One commenter stated that cutoffs areinappropriate for combustion deviceswhere the waste is destroyedimmediately upon injection into thecombustion chamber (e.g., devices thatburn liquid wastes), or if the combustionconditions supported by the waste fuelcontinue to destroy residual waste afterwaste feed cutoff. The Agency continuesto believe that the best method forreturning a combustion system to goodoperating conditions, therebyminimizing unacceptable emissions, is tostop the input of hazardous waste.Further, the burden associated withautomatic cutoffs should not besubstantial because frequent automaticwaste feed cutoffs should not occurgiven that the parameters tied into theautomatic cutoff system may bemonitored on an hourly rolling averagebasis (which allows high values to beoffset by low values) and that theAgency recommends the use of pre-alarms to warn the operator of apending cutoff (which may give theoperator time to take correctivemeasures to avoid an automatic cutoff).

In the event of a waste feed cutoff,monitoring for CO and HC (and otheroperating parameters for which limits inthe permit are based on a rollingaverage basis) must continue, and thewaste feed cannot be restarted until COand HC levels (and levels of the otherparameters) come within allowablelimits. See § 266.10g(e)(7)(ii). (For permitoperating conditions not established cna roliing average basis, the Director willspecify, on a case-by-case basis, anadequate period of time during whichthe parameters must remain withinpermit limits to demonstrate steady-state operation prior to restarting the

hazardous waste feed.) In addition,consistent with the April 27. 1990incinerator amendments proposal, theprovision of the final boiler andindustrial furnace rule requiringcompliance with the permit operatingconditions states that compliance mustbe maintained at any time there is wastein the unit. See § 266.102(e)(1). Thislanguage clarifies that activation of theautomatic waste feed cutoff does notrelieve the facility of its obligation tocomply with the permit conditions ifthere is waste remaining in the unit(such as in a rotary kiln). Thus, forexample, the air pollution controlsystem must continue to be operatedwithin the applicable permit conditions.

Furthermore, after a cutoff, thetemperature in the combustion chambermust be maintained at levelsdemonstrated during the compliance testfor as long as the hazardous waste orresidue remains in the combustionchamber. The Agency believes thistemperature requirement will helpensure that hydrocarbon emissions willbe minimized after a cutoff.

To comply with this requirement, theoperating permit must specify theminimum combustion chambertemperature after a waste feed cutoffwhile waste remains in the combustionchamber. An uninterruptable burnerusing auxiliary fuel (i.e., nonhazardouswaste fuel) of adequate capacity may beneeded to maintain the temperature inthe combustion chamber(s) and to allowdestruction of the waste materials andassociated combustion gases left in thesystem after the waste feed isautomatically cut off. The safe startup ofthe burners using auxiliary fuel requiresapproved burner safety managementsystems for prepurge, pilot lights, andinduced draft fan starts. If these safetyrequirements preclude immediatestartup of auxiliary fuel burners andsuch startup is needed to maintaintemperatures (i.e., if the combustionchamber temperatures dropprecipitously after waste feed cutoff),the auxiliary fuel may have to be burnedcontinuously on "low fire" duringnonupset conditions.

Furthermore § 206.102[e)(7)(ii)(B)requires that the combustion gases mustcontinue to be routed through the airpollution ccntrol system as long aswaste remains in the unit. One effect ofthis clarifying requirement, incombination with the requirement tomaintain compliance with permitconditions as long as there is waste inthe unit, is that opening of any type ofair pollution control system bypassstack while there is waste in the boileror furnace would be a violation of the

permit (unless the facility demonstratescompliance with the performancestandards during the trial burn, with thevent stack open).

Although we believe that suchemergency bypass stacks are notprevalent on boilers and industrialfurnaces, our discussion of this topic inthe preamble to the incineratoramendments at 55 FR 17890 (April 27,1990) would also apply to any boiler orindustrial furnace with such a bypass orvent stack. We received a number ofcomments from the incinerator industryexpressing concern that use of a bypassstack for safety purposes would beconsidered a violation. We agree thatthere can be mitigating circumstances towarrant the use of a bypass stack anddo not discredit their use as a safetydevice. However, the Agency continuesto believe that the facility can andshould implement measures to minimizesituations where use of the emergencyvent stack is necessary.

One commenter stated that the use ofhazardous waste should be prohibitedduring startup or shutdown periods for acement kiln until normal operatingtemperatures are achieved. The finalrule does not restrict hazardous wasteburning during kiln startup or shutdownprovided that the compliance (or trialburn) covers those periods ofoperations. In other words, hazardouswaste may be burned during startup andshutdown if the facility demonstratesconformance with the standards duringthose operations.

Another commenter argued thataccurate measurement of combustionchamber temperature for somecombustion devices will be difficult.Because of this difficulty, the final ruledoes not require that this temperature bedirectly measured in the combustionchamber if an owner/operator candemonstrate to permitting officials thatthe combustion chamber temperaturecorrelates with a more easily measureddownstream gas temperature.

One commenter agreed with EPA'srevised proposal not to limit the numberof automatic waste feed cutoffs, butdisagreed with EPA's requirement thatcombustion chamber temperatures mustbe maintained at the levels thatoccurred during the trail burn for theduration of time that the waste remainsin the combustion chamber. Thiscommenter believed that electric utilityboilers and other burning devices willhave difficulty in accurately measuringcombustion chamber temperatures. Forthis reason, the commenter suggestedthat waste feed cutoffs alone be used tocontrol HC emissions rather than alsorequiring that combustion chamber




temperatures be maintained. EPAbelieves that the flexibility that the finalrule allows for monitoring combustionchamber temperature and in setting thefrequency of waste feed cutoffs asdiscussed above should address thiscommenter's concerns.

Another commenter supported theproposed 10 times per month limit on thenumber of automatic waste feed cutoffsand the proposed requirement that anyfacility exceeding that frequency wouldbe required to cease burning hazardouswaste, to notify the Director, and not toresume burning hazardous waste untilreauthorized by the Director. Anothercommenter supported monthly cutofflimits because they would provide anincentive for the facility to takecorrective measures to precludefrequent cutoffs. Some commentersstated that this requirement is overlyrestrictive.

After careful consideration, EPA hasdecided to modify this requirement forthe following reasons: (1) The Agencydoes not have data indicating a specificfrequency of cutoffs which would beunacceptable at all boilers and furnacesgiven that the combustion chambertemperature and other conditions aremaintained as described above; (2] theAgency believes that operating costsassociated with cutoffs will providesufficient incentive to encourageowners/operators to minimizeautomatic waste feed cutoff incidents;and (3) the recommended use of pre-alarm systems will reduce the number ofwaste feed cutoffs. However, the finalrule allows the Director to use hisdiscretion to determine whether a limiton the frequency of cutoffs is warrantedat a specific facility.

Waste Feed Restarts. Today's ruleprovides that when the automatic wastefeed cutoff is triggered by a CO limit orwhen applicable, an HC exceedance, thewaste feed can be restarted only whenthe hourly rolling average CO/HC levelsmeet the permitted limits (e.g., 100 ppmvfor CO under Tier I).

The Agency proposed two alternativeapproaches for restarting the waste feedwhen a cutoff is triggered by a COexceedance: (1) Restart the waste feedafter an arbitrary 10-minute time periodto enable the operator to stabilizecombustion conditions; or (2) restart thewaste feed after the instantaneous COlevel meets the hourly rolling averagelimit. Eight commenters supportedrestarting the waste feed after theinstantaneous CO level meets the permitlimit. Five commenters suggested thatwaste feed can be restarted once theinstantaneous CO level meets the hourlyrolling average limit. The Agencyconsidered the comments, but continues

to believe that allowing a waste feedrestart after the hourly rolling averageequals or falls below the permitted limitis preferable. After the waste feed iscutoff, the facility will be burningnonhazardous waste (typically fossilfuel), which should result in CO and HClevels well below the allowable limits.Therefore, the hourly rolling averageshould fall below the permitted limitwithin a relatively brief period of time.Allowing the waste feed to be restartedwhen the instantaneous CO level hasdropped to the permitted level may notbe desirable, because restarting thewaste feed immediately may triggeranother cutoff due to a CO spike whenthe waste feed is restarted.

Three commenters supported theproposed approach to require the HChourly rolling average to be met beforerestarting the waste feed cutoff becauseof a HC exceedance. Three commentersopposed this approach. Instead, thesecommenters suggested a 10-minutewaiting period be used. EPA consideredthese comments but continues to believethat meeting the hourly rolling averageis a conservative approach and isappropriate after a HC exceedance,because the HC is a better surrogate fortoxic organic emissions than CO.D. CEM Requirements for PIC Controls

The final rule promulgates theproposed performance specifications forcontinuously monitoring CO, HC, andoxygen. See Methods Manual forCompliance with the BIF Regulations,incorporated as appendix IX of part 266in today's rule. The performancespecifications for HC monitoring,however, include specifications for bothhot and cold monitoring. Although hotmonitoring is generally required by thefinal rule, cold monitoring may be usedfor interim status facilities if they certifycompliance with the emissionsstandards within 18 months ofpromulgation of the rule. Even if coldmonitoring is used to certify initialcompliance, however, hot monitoring isrequired for these facilities when theyrecertify compliance and when they areissued a RCRA operating permit.

One commenter stated that an HCmonitoring system is readily availablefor continuous emissions monitoring(CEM), while five commentersmaintained that HC analyzers haveserious operational problems. Severalcommenters requested that alternate HCCEM methods be allowed, specificallymonitors with non-dispersive infra-red(NDIR) detectors rather than therequired flame ionization detector (FID).One commenter noted that EPA has notvalidated the FID method for HCanalysis nor has it provided any critical

discussion of the current methods of HCanalysis.

The Agency considered the use ofNDIR detectors for HC monitoring butbelieves that NDIR systems havelimitations compared to FID systems.EPA believes that FID systems are moresensitive than NDIR systems and that anequivalent response is not found withNDIR detectors. The final rule requiresthe use of FID detectors for HCmonitoring.

Four commenters recommendedmonitoring nonmethane hydrocarbons(NMOC) as opposed to "total" HCbecause methane, which ispredominately emitted from fuelsources, has a high FID response factor.Furthermore, these commenters wouldlike EPA to require testing for specificPICs that respond poorly to HC monitorsduring test burns. One commenter statedthat HC monitors can be varied easily todetect NMOC. EPA does not agree witheither suggestion. The Agency isrequiring HC monitoring to indicatewhether the device is operating undergood combustion conditions. Weacknowledge that the largest fraction oforganic compounds that the HCmonitoring system required by the finalrule will detect for facilities operatingunder good combustion conditions willbe compounds that are relativelynonhazardous (e.g., methane). Inaddition, some hazardous compounds,particularly highly chlorinatedcompounds) will be under-reported.Thus, although the promulgatedapproach would not be adequate for thepurpose of assessing the risk that HCmay pose from a given facility, theapproach is adequate for its intendedpurpose-a measure of whether thefacility continues to operate within goodcombustion conditions. This is becauseEPA's emissions testing has shown thatwhen combustion conditionsdeteriorate, the compounds that arereadily detected by the promulgated HCmonitoring system increasecorrespondingly.

In addition, if a NMOC system wereused, the 20 ppmv HC limit would haveto be lowered to account for themethane fraction that would no longerbe counted. Commenters did not providesupport for so adjusting the proposedHC limit. Further, the Agency isconcerned that NMOC detectors maynot be able to provide continuous datadue to the time required for methaneseparation. The Agency has also foundthat HC CEMs are more durable thanNMOC CEMs, and thus less prone toreliability problems. As a result, theAgency has concluded that HC CEMsare more likely to provide a continuous

71 61




indication of combustion conditionsthan is possible with an NMOC monitor.

Hot Versus Cold HC MonitoringSystems. Except as indicated below, thefinal rule requires the use of a hot orunconditioned HC monitoring systemthat must be maintained at atemperature of at least 150 °C until thesample gas exits the detector. Seeperformance specifications in MethodsManual for Compliance with the BIFRegulations (incorporated in today's ruleas appendix IX of part 266). Given,however, that the technology has justrecently been demonstrated 30 to becontinuously operational on hazardouswaste combustion devices, the final ruleallows the use of a conditioned gasmonitoring system during the initialphase of interim status operations.Facilities in interim status that certifycompliance with the emission standardsfor metals, HCl, Cl, particulate matter,CO and HC within 18 months ofpromulgation of the final rule may use aconditioned gas system. Facilities thatelect to obtain the automatic 12-monthextension (or a case-by-case extension)of the 18-month certification deadline,however, may not use a conditioned gassystem because the additional timeprovided by the extension will alsoprovide time to install an unconditionedHC monitoring system. These facilitiesmust demonstrate compliance with theHC limit using an unconditioned gasmonitoring system. Further, facilitiesthat certify initial compliance using aconditioned gas (cold) system must usean unconditioned gas (hot) system whenthey recertify compliance within threeyears of certifying initial compliance.

EPA is requiring the use of a hotmonitoring system because it representsbest demonstrated technology given thata larger fraction of HC emissions can bedetected with a hot system. Asdiscussed at proposal, a hot HCmonitoring system can detect asubstantially larger fraction ofhydrocarbon emissions than a coldsystem. This is because the cold systemuses a gas conditioning system thatremoves semi- and nonvolatilehydrocarbons and a substantial fractionof water-soluble volatile hydrocarbons.

EPA received numerous commentsregarding gas conditioning (heatedversus unheated) for HC monitoring.Eight commenters are in favor of gasconditioning. The purpose of gas

3e Entropy Environmental Inc, "Evaluation ofheated THC Monitoring Systems for HazardousWaste Incinerator Emission Measurement", DraftFinal Report, October 1990; and Shamat, Nadim, atal., "Total Hydrocarbon Analyzer Study", Paperpresented at the 63rd Water Pollution ControlFederation Conference in Washington, DC, October8, 1990.

conditioning is to remove moisture fromthe combustion gases that can degradeinstruments or plug sample lines.Sample conditioning, however, can alsoremove some of the water solublehydrocarbons and the semi- andnonvolatile hydrocarbons in the flue gassuch that methane and othernonhazardous volatile hydrocarbons arefrequently the dominant constituentsmeasured by the detector. Somecommenters were concerned that fewerPICs would be detected by aconditioned (i.e., cooled) monitoringsystem. However, one commenter statedthat even though the constituentscontributing most of the hypotheticalrisk are relatively nonvolatile they arerelatively nondetectable through anunconditioned (heated) monitoringsystem because of their halogen content.

As discussed at proposal, the Agencyis using HC monitoring to implement thetechnology-based HC limit of 20 ppmvas an indicator of good combustionconditions. The HC monitor is not usedin an attempt to quantify organicemissions for risk assessment purposes.Emissions testing has shown that duringcombustion upset conditions, both thehot and cold HC monitoring systemsdetect an increase in HC levels becauseunder upset conditions there is asubstantial increase in hydrocarboncompounds that are readily detected byeither monitoring system.3 7

One commenter suggested that, ratherthan specifying a range of 40-64 *F foroperation on the conditioner asproposed, a specific conditioningtemperature (32 *F) should be requiredto precisely define the conditionedsampling procedure. We agree that aminimum temperature should bespecified rather than the range. The finalrule allows a conditioned monitoringsystem during the initial phase ofinterim status, and requires that thesample gas temperature must bemaintained at a minimum of 40 "F at alltimes prior to discharge from thedetector. EPA selected a minimumtemperature of 40 "F from the range of 40to 64 "F to ensure that moisture waseffectively removed from the gas sampleto preclude plugging and foulingproblems with the monitoring system.

Three commenters suggested that theHC limit of 20 ppmv be re-examinedbecause gas conditioning temperaturesor other changes in the measurement

37 EPA Is requiring the use of a hot.unconditioned HC monitoring system (except undercertain circumstances during the initial phase ofinterim status) because hot systems are,nonetheless, more conservative in that they detect alarger fraction of organic compounds in emissions.Further, hot systems represent best demonstratedtechnology for monitoring HC levels.

method may influence the amount of HCmeasured. Given that the 20 ppmv limitis based primarily on test burn datausing heated (i.e., unconditioned)monitoring systems, the Agencyconsidered lowering the 20 ppmv limitwhen a cold (i.e., conditioned)monitoring system is used. (Limited fieldtest data indicate that a heated systemwould detect from 30% to 400% more ofthe mass of organic compounds than aconditioned system.) We believe,however, that the 20 ppmv HC limit isstill appropriate when a conditionedsystem is used because: (1) The datacorrelating heated vs conditionedsystems are very limited; (2) the data onHC emissions are limited (and thereapparently is confusion in some cases asto whether the data were taken with aconditioned or unconditionedmonitoring system); and (3) the Agency'srisk methodology is not sophisticatedenough to demonstrate that a HC limitof 5 or 10 ppmv using a conditionedsystem rather than an unconditionedsystem is needed to protect humanhealth and the environment. The SAB 3salso concurs with this view. (Moredetailed responses to comments on thisissue are found in a separatebackground document.)

E. Control of Dioxin and Furan'Emissions

For facilities that may have thepotential for significant emissions ofchlorinated dibenzodioxins anudibenzofurans (CDD/CDF), the final rulerequires emissions testing for bothinterim status and new facilities todetermine emissions rates of all tetra-octa congeners, calculation of a toxicityequivalency factor, and dispersionmodeling to demonstrate that thepredicted maximum annual averageground level concentration (i.e., thehypothetical maximum exposedindividual) does not exceed levels thatwould result in an increased lifetimecancer risk of more than I in 100,000. 3

9

The Agency considers a facility to havethe potential for significant CDD/CDFemissions if it is equipped with a dryparticulate matter control device (e.g.,fabric filter or electrostatic precipitator)

38 U.S. EPA, "Report of the Products ofIncomplete Combustion Subcommittee of theScience Advisory Board", Report # EPA-SAB-EC--90-004, January 1990.

39 EPA is not requiring that the estimated cancerrisk from CDD/CDF be added to the risk from metalemissions to demonstrate that the summed risk tothe maximum exposed individual is less than 10- .The Agency believes that it is inappropriate to sumthe estimated health risk from metals that areknown or probable human carcinogens with atoxicity equivalency factor for CDD/CDF that isdesigned to be very conservative.




with an inlet gas temperature within therange of 450 to 750 *F, or if it is anindustrial furnace that has hydrocarbonlevels exceeding 20 ppmv. See § 266.104.

Dispersion modeling must beconducted in conformance with EPA's"Hazardous Waste Combustion AirQuality Screening Procedure" providedin Methods Manual for Compliance withthe BIF Regulations or EPA's Guidelineon Air Quality Models (Revised) whichare incorporated in today's rule asappendices IX and X. respectively, ofpart 266, or 'EPA SCREEN ScreeningProcedure" as described in ScreeningProcedures for Estimating Air QualityImpact of Stationary Sources. The latterdocument is incorporated by referencein today's final rule at § 260.11. Toevaluate potential cancer risk from thecongeners, prescribed procedures mustbe used to estimate the 2.3,7,8-TCDDtoxicity equivalence of 2,3,7,8-chlorinated congeners. See "Proceduresfor Estimating Toxicity Equivalence ofChlorinated Dibenzo-p-Dioxin andDibenzofuran Congeners" in MethodsManual for Compliance with the BIFRegulations incorporated in the rule asappendix IX of part 266.

Studies conducted by the Agency '0and others 4 1 during development ofregulations for municipal wastecombustors (MWCs) concluded that PMcontrol devices operated attemperatures greater than 450 °F havethe potential for emitting elevated levelsof CDD/CDF. At these temperatures,precursor organic materials and chlorinein the flue gas can be catalyzed by PMcaptured in the PM collection device toform CDD/CDF. Based on thesefindings, the Agency proposed to restrictthe combustion of hazardous waste inBIFs that operate with PM controldevice temperatures greater than 450 °F.

A number of commenters opposed theproposed limitation on the flue gastemperature to less than 450 *F. Severalcommenters pointed out technicaldistinctions among types of boilers andindustrial furnaces that affect the abilityof a unit to change flue gas temperatureand the potential of an ESP to formCDD/CDF. For example, many boilerand industrial furnaces either combustwastes that are very low in chlorine orthat have high levels of chlorine capturewithin the process (e.g., cement kilns).

40 See U.S. EPA, "Municipal Waste CombustionStudy: Combustion Control of Organic Emissions".EPA/530-SW-87-021C. NTIS Order No. PB87-20609& U.S. EPA. "Municipal Waste CombustionStudy: Flue Gas Cleaning Technology". EPA/530-SW-87-021D, NTIS Order No. PB87-20810; and 54FR 52251 (December 20, 1989).

4' Vogg H. end L Stieglit, -hermai Behavior ofPCDD/PCDF in Fly Ash from Municipal WasteIncinerators", Chemosphere. pp. 1373-1378, 1968.

As a result, the CDD/CDF emissionpotential will vary for different boilersand industrial furnaces, as well asbetween boilers and industrial furnacesand MWCs. Commenters also statedthat there is no direct evidence of CDD/CDF emissions from several types ofboilers and industrial furnaces, and thatcompliance testing to demonstrate 99.99percent DRE of POHCs and continuousmonitoring of CO and HC levels isadequate to ensure minimal emissions oforganic compounds.

The Agency has reviewed theavailable data on the theory of CDD/CDF formation as well as CDD/CDFemissions from BIFs. Based on thisreview, the Agency agrees that most, butnot necessarily all, BIFs burninghazardous waste have low CDD/CDFemission rates. For example, EPArecently tested a cement kiln burninghazardous waste that operates with anESP at a temperature of 500-500 °F andfound it to have relatively high CDD/CDF emissions.4 2 (EPA conducted a riskassessment, however, that estimated theincreased lifetime cancer risk to thehypothetical maximum exposedindividual from the CDD/CDF emissionsranged from 7 in 10,000,000 to 2 in1,000,000 without burning hazardouswaste and from 2 in 1,000,000 to 4 in1,000,000 when burning hazardouswaste, well under the 1 in 100,000 limitestablished in today's rule.) The Agencysuspects that the elevated CDD/CDFconcentrations in the stack gas at thiscement kiln are the result of the ESP'soperating temperature and the level ofHC precursor material in the flue gas.HC concentrations ranged from 66 to 70ppmv (measured with a hot system.reported as propane, and corrected to7% oxygen, dry basis) withouthazardous waste burning and from 38ppmv to 63 ppmv with hazardous wasteburning. (We note that to continueburning hazardous waste under today'srule, the Director must establish duringthe part B permit proceedings analternative HC level for this kiln basedon a demonstration by the applicant thatHC levels are not higher when burninghazardous waste than under normalconditions and that the facility isdesigned and operated to minimize HCemissions from all sources-fuels andraw materials. At certification ofcompliance with the emissions controlsother than the HC limit, this facilitymust also propose a HC concentrationlimit for the remainder of interim status(until that limit or another limit isestablished under permit proceedings)

41 U.S. EPA. Emissions Testing of a Wet CementKiln at Hannibal, MO, December 1990.

that will ensure that HC levels whenhazardous waste is burned will not behigher than baseline levels (i.e., HClevels when the system is designed andoperated to minimize HC emissions fromall sources, when burning normal fuelsand feeding normal raw materials toproduce normal products, and when notburning hazardous waste).) In addition,trial burn emissions testing mustdemonstrate that emissions of organiccompounds are not likely to result in anincreased lifetime cancer risk to thehypothetical maximum exposedindividual exceeding I in 100,000. See§ 266.104(f) and discussion in sectionL.B.4.b of part three of this preamble.)There may be other factors thatinfluence CDD/CDF levels at thisfacility (and other facilities), but this isuncertain. In addition, the exact HCconcentration in combustion gas belowwhich elevated CDD/CDFconcentrations will not occur isunknown.

The Agency continues to believe thatthe operating temperature of the PMcontrol device (and HC concentrationsin flue gas) plays a significant role inCDD/CDF emissions. For a given HCconcentration in the flue gas, theavailable data suggest that the potentialfor elevated CDD/CDF emissions is lowif the PM control device operates attemperatures of less than 450 °F orabove 750 *F. Consequently, today's ruledoes not require BIFs with PM controldevices operating at temperaturesoutside of the 450-750 *F window todetermine CDD/CDF emission rates(unless it is an industrial furnace withHC levels greater than 20 ppmv).Owners and operators of units operatingwithin the temperature window,however, are required to conduct stacktesting to determine CDD/CDF emissionrates and to conduct a risk assessmentusing prescribed procedures todemonstrate that the estimatedincreased lifetime cancer risk to thehypothetical maximum exposedindividual is less than 1 in 100,000.

The Agency notes that the final rulemunicipal waste combustors (MWCs)may take a slightly different approach tocontrol dioxin and furans by limitingtemperatures at the inlet of the PM airpollution control system to within 30 *Fof those achieved in a dioxin/furancompliance test. The preamble to thatrule, however, will probably continue tonote the possibility of dioxin/furanformation in the temperature range of230 °C (450 *F). In today's rule, theAgency believes that using temperatureand HC levels as a trigger to dioxin/furan testing and risk assessment will befully protective of human health and the

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environment and somewhat easier toimplement than the MWC approach.

Ill. Risk Assessment Procedures

The Agency uses assessment of healthrisk to develop and implement the finalrules for metals, hydrochloric acid (HCI),and chlorine gas (C12). Specifically, theAgency has used risk assessment to: (1)Establish ambient air concentrations ofappendix VIII compounds that do notpose an unacceptable health risk forpurposes of this rulemaking; and (2)establish risk-based, conservative feedrate and emissions Screening Limits formetals and HCI. In addition, if facilitiesfail the Screening Limits or elect toconduct dispersion modeling to obtainless conservative limits, the rule allowsfacilities to use site-specific dispersionmodeling to establish emission limits,and ultimately feed rate limits for metalsand chlorine.

To establish health-based acceptableambient concentrations fornoncarcinogenic toxic metal andnonmetal compounds (except for HCl,Cl2 and lead), EPA converted oralreference doses to reference airconcentrations (RACs) by assumingaverage breathing volumes and bodyweights, and by applying a safety and abackground level factor. See 54 FR at43756. Health-based concentrations forcarcinogenic pollutants were derived byconverting cancer potency factors, orslopes (unique for each carcinogen), intoRisk Specific Doses (RSDs) at a risklevel of 1 in 100,000. 4

3 Since carcinogensare assumed to pose a small but finiterisk of cancer even at very low doses,the RSD reflects a certain risk level,corresponding to 1 chance in 100,000, or10- 5 excess risk of cancer for themaximally exposed individual ifexposed continuously to multiplecarcinogenic chemicals for a 70-yearlifetime. RACs for HC1 and C12 arebased on inhalation data, and a RAC forlead is based on the National AmbientAir Quality Standard (NAAQS).

To establish the Screening Limits formetals and HCI, air dispersion modelingwas applied to back-calculate maximumacceptable feed rates and stackemissions rates from risk-based,acceptable ambient concentrations.These calculations were performed forvarious terrain types, effective stackheights, and land use classifications.The resulting permissible ScreeningLimits reflect plausible, reasonable

43 We note that the cancer risk from thecarcinogenic metals must be summed to ensure thatthe summed risk is not greater than 1 in 100,000.Thus, when more than one carcinogenic metal isemitted, the allowable groUnd level concentrationfor each carcinogenic metal is less than the 10- 1Risk Spe~ific Dose for that metal.

worst-case assumptions about a genericfacility that are not site-specific. TheScreening Limits process provides arapid and convenient risk-basedmechanism to determine compliance.Conservative assumptions used toestimate health impacts exposure in theScreening Limit process include: (1) Useof reasonable, worst-case estimate ofdispersion of stack emissions; and (2)for the Tier I febd rate Screening Limits,assuming that all metals and chlorinefed into the.BIF in all feedstreams areemitted (i.e., there is no partitioning tobottom ash or product, and not removalby an air pollution control system.44 See52 FR 17002 (May 6, 1987) and 54 FR43729 (October 26, 1989). Thus,assumptions and the Screening Limitstend to err intentionally on the side ofprotecting human health.45

If emission levels exceed theScreening Limits (or if the owner/operator so elects), the rule allows afacility to conduct its own site-specificair dispersion modeling in order toestablish metals, HCI, and C12 emissionlimits. Incorporation of site-specificinformation allows less conservativeassumptions (than the reasonable worst-case, nonsite-specific defaults) to beused in the dispersion models.Consequently, site-specific airdispersion modeling may predict lowerambient concentrations than thenonsite-specific modeling reflected inthe Screening Limits, thus allowinghigher emissions and feed rate limits.

A. Health Effects Data

1. Carcinogens

Health effects evaluations forcarcinogens have been summarized inPart Three, I. D, "Evaluation of HealthRisk" in the April 27, 1990 proposal (see55 FR 17873). To summarize briefly, in'contrast to noncarcinogens, carcinogensare assumed to present a small but finiterisk of causing cancer, even at very lowdoses. The slope of the dose-responsecurve in the low dose region is assumedto be linear for carcinogens. Because of

44 To obtain credit for partitioning to residue orproduct and for APCS removal efficiency, ownersand operators must conduct emissions testing todemonstrate the overall System Removal Efficiency(SRE-partitioning plus APCS removal efficiency.The Agency has not assumed an SRE in developingthe Tier I feed rate Screening Limits because thereare many site-specific factors that can affect theSRE.

45 We note that the Screening Limits may notalways be conservative, however. Today's ruleidentifies criteria whereby the Screening Limits maynot be used because they may not be conservative.See § 266.106(6). That paragraph in the rule alsogives the Agency authority to determine whetherthe Screening Limits may not be protective in aparticular situation. In that case, the owner andoperator must use the Tier Ill procedures---site-specific dispersion modeling.

this, the slope of the curve in the lowdose region may be. used as an estimateof carcinogenic potency. The unit risk isdefined as the incremental lifetime riskestimated to result from exposure of anindividual for a 70-year lifetime to acarcinogen in air containing 1 microgramof the compound per cubic meter of air[tg/mg. At an air concentration of 1 )xg/m

3 , the cancer potency slope isnumerically equivalent to the unit risk.Thus, at a preselected risk level, thecorresponding air concentration whichwould cause that risk may be calculatedby dividing the desired risk level by theunit risk value. Although the resultingvalue represents an air concentrationwith units of pg/m 3, this concentrationis referred to as the Risk Specific Dose(RSD).

When exposed to more than onecarcinogen, the Guidelines forCarcinogenic Risk Assessment (51 FR33992 (September 24, 1986)) recommendadding risks from the individualcarcinogens to obtain the aggregate risk(i.e., cancer risks from exposure to morethan one carcinogen are assumed to beadditive). For today's rule, the Agencyhas proposed that an aggregate risklevel for metals (i.e., arsenic, beryllium,cadmium, and hexavalent chromium) of10- 5 is appropriate because it wouldlimit the risk level for individualcarcinogens to the order of 10- . TheAgency points out, however, that inselecting the appropriate risk level for aparticular regulatory program, itconsiders such factors as the particularstatutory mandate involved, nature ofthe pollutants, control alternatives, fateand transport of the pollutant indifferent media, and potential humanexposure. See, e.g., 54 FR at 38049 (Sept.14, 1989). Particular factors bearing onthe Agency's choice here include thewide array and potentially largevolumes of carcinogenic pollutants thatcan be emitted by these devices (unlikethe situation in such rules as thebenzene NESHAP when a singlepollutant with well-understood effectswas at issue), the need to guard againstenvironmental harm as well as harm tohuman health, potential synergisticeffects of the carcinogens emitted bythese devices (which effects are notaccounted for by the risk assessment),and legislative history indicatingCongressional preference for parity ofregulation between BIFs burninghazardous waste fuels and hazardouswaste incinerators (S. Rep. No. 284, 98thCong. 1st Sess. 38)). In addition, theincreased recognition of the need tocontrol net air emissions of toxicpollutants generally, manifest in Title IIIof the Clean Air Act Amendments of




1990, influences the Agency's choice of aconservative risk target in this rule.These same factors can also influencechoice of a risk level where the Agencyis making site-specific determinations.

The following section discussescomments on health effects data oncarcinogens.

a. Unit Risk Factors/Risk SpecificDoses. A few commenters argued fordeletion of category C carcinogens fromconsideration in the risk assessmentprocess.

Given that the carcinogenic metalsarsenic, beryllium, cadmium, andhexavalent chromium are classified aseither A or B carcinogens, thisdiscussion pertains only to the Cnonmetal appendix VIII compounds forwhich the Agency established 10-5RSDsfor purposes of implementing the lowrisk waste exemption, risk assessmentsfor cement kilns with HC levelsexceeding 20 ppmv, and health-basedlimits for Bevill excluded waste.

As a conservative element in the riskassessment process, and especially forpurposes of implementing an exemptionfrom some of the emission controls, EPAdoes not believe that exposure tocategory C carcinogens should beignored at this time for those chemicalswith cancer potency slopes. Theclassification schemes categorizechemicals based upon weight of theevidence, not carcinogenic potency.Therefore, a highly potent carcinogenmay be classified in the C category andpresent a threat to health.

b. Quality of the Toxicological DataBase. Several commenters questionedthe quality and extent of the toxicologydata base and EPA's selection ofspecific studies used to calculate thecancer potency factors and unit riskvalues for a particular chemical. Forexample, one commenter noted that themolecular species of a metal compoundemitted from an incinerator may bemarkedly different from the metalliccomplex actually tested forcarcinogenicity and used to calculatethat metal's cancer potency factor. Thiswould distort the risk assessmentprocess. This same commenter arguedthat beryllium oxide, which would beformed preferentially at the extremetemperatures of a furnace, is relativelyinert compared to the molecularcomplex of beryllium which forms thebasis of the cancer potency factor.Another commenter contended that, ingeneral, the less water soluble (and,therefore, less bioavailable) metallicoxides are emitted from incineratorswhereas the metallic species tested forcancer were more water soluble andbioavailable (i.e., absorbable into theorganism).

EPA acknowledges the concern thatthe metal complex tested forcarcinogenicity in animals reflects thatto which humans are exposed. However,the particular metal complex beingemitted may not have been tested inanimals. In such cases, it is sometimesnecessary to use that toxicological datawhich is available (on the same metalbut complexed with a different ligand),limitations notwithstanding, untilappropriate data on the complex ofconcern become available. EPA believesthe use of the available data base willresult in risk assessment methodologythat is protective of human health and*the environment.

Moreover, EPA notes that solublemetallic salts may also be emitted undersome conditions (e.g., metallicchlorides). For screening purposes, theconservative assumption that soluble[i.e., bioavailable) metallic complexesare emitted, is assumed to protecthealth. For the site-specific riskassessment option, historical or testburn data may be used to identifyprobable emitted metallic species. Ifpermit officials conclude during thepermit process that appropriate fate,transport, and toxicological data existfor the actual emitted complex tosupport risk assessment, this could thenbe used in the site-specific riskassessment option.

c. High Dose to Low DoseExtrapolation. Several commentersquestioned the scientific merit ofextrapolating from high doseexperimental data to low dose cancerrisks using existing statistical models,asserting that the process is notbiologically-based and is extremelyconservative (i.e., overly health-protective); Two commenters assertedthat the linearized multistage modelshould not be applied to non-genotoxiccarcinogens because such "carcinogens"promote rather than initiate cancer, thusacting as a classical toxicant with athreshold. These commentersmaintained that a chemical such aschloroform, which they claim is non-genotoxic (i.e., has not tested positive inmutation assays), would have athreshold below which there is no riskof cancer. Another commenter arguedthat biological evidence indicates athreshold for arsenic-induced cancerdue to its known benefit as an essentialtrace element at low doses. This samecommenter asserted that hexavalentchromium (Cr+6) is quickly convertedin the body to the essential traceelement Cr+3 and, therefore, should betreated as a "threshold carcinogen."

The Agency is following closelyrecent developments in scientificconsensus regarding the basic molecular

biology of cancer. EPA will revise itsguidelines for carcinogen riskassessment, and other guidancedocuments, to reflect developingscientific theory on high to low doseextrapolation threshold effects, andother related issues. Until that time, EPAwill continue to use its currentapproach, believing that a moreconservative approach is warranted inthe face of uncertainty.

d. Chromium Oxidation State. Severalcommenters argued that the currentproposal does not differentiatechromium in the +6 oxidation statefrom chromium +3. They contend thatmost chromium emitted from boilers,industrial furnaces, and incineratorsexists in the +3 state. Consequently, theproposed approach, which assumes thatall chromium is +6, may overstate risksdrastically. The commentersrecommended that EPA assume thatonly a fraction of the chromium emittedby incinerators exists in the +6oxidation state.

EPA concludes that assuming that100% of the chromium is in thehexavalent oxidation state is aconservative assumption taken in theface of limited data. In a test 48 ofhazardous waste incinerator emissionsunder varying levels of total chlorine inthe waste burned, a high percentage ofthe total chromium emitted was in thehexavalent state under certainconditions. Until more data is available,showing consistently lower proportionsof Cr 6 under a variety of combustionconditions, EPA believes it is health-protective to assume that chromiumfrom incinerator emissions exists in thehexavalent state. Facilities may elect toconduct emissions testing to determinethe actual emission rate of Cr"6 .

e. Additive Risks. One commentercriticized EPA's selection of 10 - 5 as ticeacceptable aggregate risk level (forcarcinogenic metals) for derivingscreening limits, and claimed theselection is arbitrary and inconsistentwith other EPA policy. EPA policy, thecommenter notes, has traditionallyembraced a range of risks from 10- 7 too-4, with the final EPA-selected risk

level dependent upon site-specificconditions (i.e., characteristics and sizeof the exposed population).

EPA's rationale for selecting 10- 5 riskfor the MEI is described in the October26, 1989 supplemental notice (54 FR43754). In summary, EPA continues tobelieve that the aggregate cancer risk to

46 U.S. EPA, "Pilot Scale Evaluation of the Fate ofTrace Metals in a Rotary Kiln Incinerator with aVenturi Scrubber/Packed Column Scrubber, Vol. 1,Technical Results", April 1989.

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the MEI of 10- 5 for metals is appropriatebecause: (1) It provides adequateprotection of public health; (2) itconsiders weight of evidence of humancarcinogenicity; (3) it limits the risk fromindividual Group A and B carcinogens torisk levels on the order of 10- t and (4] itis within the range of risk levels theAgency has used for hazardous wasteregulatory programs. See also thediscussion in section III.A.1 of part threeabove.

2. Noncarcinogens. For toxicsubstances not known to displaycarcinogenic properties, there appears tobe an identifiable exposure thresholdbelow which adverse health effectsusually do not occur. Noncarcinogeniceffects are manifested when thesepollutants are present in concentrationsgreat enough to overcome thehomeostatic, compensating, andadaptive mechanisms of the organism.Thus, protection against the adversehealth effects of a toxicant is likely to beachieved by preventing total exposurelevels that would result in a doseexceeding its threshold. Since othersources in addition to the controlledsource may contribute to exposure,ambient concentrations associated withthe controlled source should ideally takeother potential sources into account.Therefore, the Agency hasconservatively defined reference airconcentrations (RACs) fornoncarcinogenic compounds that aredefined in terms of a fixed fraction ofthe estimated threshold concentration.The RACs for lead and hydrogenchloride, however, were establisheddifferently, as discussed below. TheRACs established in today's final ruleare identical to those proposed. (Seeappendix H of the Supplement toProposed Rule at 54 FR 43762 (October26, 1989)). (The Agency notes that itdoes not intend for RACs to be used asa means of setting air quality standardsin other contexts. For instance, the RACmethodology does not imply a decisionto supplant standards established underthe Clean Air Act.)

We note, however, that the RACsproposed in appendix H of thesupplement to proposed rule (andpromulgated today as appendix IV tothe rule) included both Agency-verifiedand unverified values. Unverified valuesare subject to revision as the Agency'sReference Dose Workgroup continues toestablish verified inhalation RfDs.(Occasionally, the Agency may alsorevise verified valies based on new andsignificant information.) Since thesupplemental notice, the Workgroup hasestablished inhalation RfDs for eightcompounds on proposed appendix H

(and promulgated appendix IV to therule). The basis for the newly-verifiedRfDs is set forth in the Health EffectsAssessment Summary Tables. FourthQuarter-FY90, U.S. EPA, OERR 9200 6-303 (90-4), September 1990.4 7

Consequently, RACs based on thoseRfDs are different from the proposedand promulgated RACs. The RACsbased on verified inhalation RfDs areshown in the table below. EPA will usethe omnibus permit authority of§ 270.32(b)(2) to use these revised RACswhere the facts warrant.45

RAC in RAC basedCompound appendix IV on recently

of final rule verified RfD(pg/rn3) (pg/m3b)

Acroelin (107-02-8) ..... 20 0.03Carbon Disulfide (75-

15-0) ........................... 200 3p-Dichlorobenzene1 (106-46-7) ................. 10 200Bromomethane (74-

83-9) ........................... 0.8 2Hydrogen Sulfide

(7783-06-4).. 3 0.2Mercury (7439-97-6) 0.3 0.08Methoxychlor (72-43-

5) ................................. 50 4Toluene (108-88-3) 300 500

RACs have been derived from oralreference doses (RfDs) for thosenoncarcinogenic compounds listedappendix VIII of 40 CFR part 261 (exceptfor lead, HCI, and Cl 2 ) for which theAgency considers that it has adequatehealth effects data. An oral RfD is anestimate (with an uncertainty of perhapsan order of magnitude) of a daily oraldose (commonly expressed with units ofmg/kg-day) for the human population(including sensitive subgroups) that islikely to be without an appreciable riskdeleterious effects, even if exposureoccurs daily for a lifetime. Since theseoral RfDs are subject to change, EPAwill undertake rulemakings as necessaryif the derivative RACs change in a waythat affects the regulatory standard (seealso the discussion of this issue in theBoiler/Furnace supplemental noticepublished on October 26, 1989 at 54 FR43718). We note that, in the interimbefore any such rulemaking is complete,

'7 The document is available from the NationalTechnical Information Service (NTIS), 5285 portRoyal Road, Springfield. VA 22161, (703) 487-4600.The document number is PB90-921-104.

48 EPA notes that permit writers choosing toinvoke the omnibus permit authority of§ 270.32(b)(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

and as discussed above, permit officialsmay use the omnibus permit authority 49

of the statute to consider revised healtheffects data in establishing permitconditions.

The Agency's rationale for using oralRfDs as a basis for RAC-derivation isdescribed in 54 FR 43755 (October 26,1989). EPA believes the approach toderive RACs is reasonable because: (1)the RfDs are verified by an EPAworkgroup whose decisions are subjectto public review; (2) the verificationprocess addresses long term (lifetime)exposure; (3) the RfDs are based on thebest available information meetingspecific scientific criteria; (4) the mostsensitive individuals are considered;and (5) the RfD determination takes intoaccount the confidence in the quality ofthe information on which they arebased. Nevertheless, the Agency'sInhalation RfD Workgroup is developingreference dose values (concentrations)for inhalation exposure for severalchemicals, and some are currentlyavailable. As reference concentrationsare established by the Workgroup, theAgency will consider the need to changethe RACs established in today's rule asdiscussed above.

The final rule regulates HCI emissionsbased on an annual exposure (long-term) RAC of 7 pg/m 3.50 The RAC isbased on the threshold of priority effectsresulting from exposure to HCL.Background levels were considered tobe insignificant given that there are notmany large sources of HCI and that thispollutant generally should not betransported over long distances in thelower atmosphere.

The Agency also proposed a short-term (i.e., 3-minute exposure) RAC forHCL. The Agency agrees withcommenters, however, that the proposedRAC was not technically supportable.See discussion in section V of part threeof this preamble. Consequently, the finalrule does not establish a short-term RACfor HCL.

To consider the health effects fromlead emissions, we adjusted theNational Ambient Air Quality Standard(NAAQS) by a factor of one-tenth toaccount for background ambient levels

49 EPA notes that permit writers choosing toinvoke the omnibus permit authority of .J 270.32(b)(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

so U.S. EPA. Integrated Risk Information System(IRIS) Chemical Files.




and indirect exposure from the source inquestion. Thus, although the leadNAAQS is 1.5 pg/m s , for purposes ofthis regulation, sources could contributeonly up to 0.15p.g/m3. Given, however,that the lead NAAQS is based on aquarterly average, the equivalent annualexposure is 0.09 ,g/ms.

Finally, section 109 of the Clean AirAct (CAA) requires EPA to establishambient standards for pollutantsdetermined to be injurious to publichealth, allowing for an adequate marginof safety. Secondary NAAQS, alsoauthorized by section 109, must bedesigned to protect public welfare inaddition to public health, and, thus, aremore stringent. As discussed above, theReference Air Concentration (RAC)used in today's rule for Lead is based onthe Lead NAAQS. As the Agencydevelops additional NAAQS for toxiccompounds that may be emitted fromhazardous waste incinerators, we willconsider whether the acceptableambient levels (and, subsequently, thefeed rate and emission rate ScreeningLimits) ulimately established under thisrule should be revised. We note againthat the reference air concentrationvalues (and risk-specific dose values forcarcinogens] presented here in no waypreclude the Agency from establishingNAAQS as appropriate for thesecompounds under authority of the CAA.

a. Derivation of Oral RfDs/RA Cs.Many commenters responded to theissue of derivation of oral RfDs/RACs,questioning the scientific basis for theoral RfDs and conversion of RfDs toRACs. Some commenters stated that useof oral RfDs do not factor in differencesin routes of exposure (e.g., absorption,first-pass effects) when extrapolatingfrom oral to inhalation routes ofexposure. As discussed above, weacknowledge the limitations ofdeveloping RACs from oral RfDs butcontinue to believe the approach used isreasonable and the best availableapproach until the Agency's InhalationRfIJ Workgroup can provide inhalationvalues.

Other commenters directed theircomments exclusively to lead, indicatingthat the lead RAC was arbitrary. EPAhas based the lead RAC on the NationalAmbient Air Quality Standard(NAAQS]. This was done in partbecause no reference dose or cancerpotency slope is currently available forthis metal. The final rule uses 10%,rather than 25% as is used for othercompounds, as an apportionment factor(as proposed because the Agency isparticularly concerned with: (1) Thepossible high contribution of leadexposure by indirect pathways,

particularly in urban environments; and(2) the growing concern of low level leadexposure in children since the leadNAAQS was established. (The Agencycurrently plans to propose to readjustthe lead NAAQS in 1991.)

b. Apportionment. Some commentersquestioned EPA's proposal apportioning75% of the RfD to other non-specifiedsources, thus causing the RAC tocorrespond to 25% of the RD. Thecommenters indicated that the figure of75% from other sources was arbitraryand could vary from one chemical toanother. They suggested that unlessother sources of exposure wereidentified, the RAC should reflect 100%of the RfD.

EPA has chosen a fraction (25%) of theRfD to serve as the basis for the RACsbecause indirect pathways, known tocontribute to risks, are not quantified inthese regulations. Even apart fromexposures contributed by sourcesseparate from the boiler, industrialfurnace, or incinerator, indirectpathways from emissions from thesedevices themselves may contribute 75%or more to risk. Such indirect (i.e., non-inhalation) pathways include depositionof emitted chemicals on: (1) Gardensand crops directly consumed byhumans; (2) meadows used for grazingby beef cattle and other edible livestock;and (3) meadows and fodder used bydairy cattle (and subsequent milkconsumption by humans).

Such real exposures, which are notquantified in these rules, are accountedfor by the allowance for 75%contribution from other sources.Moreover, it is questionable whetherany single facility should be allowed toconsume 100% of an individual'sexposure allowance, above which anyfurther exposure might cause adversehealth effects.

B. Air Dispersion Modeling

The Agency used air dispersionmodeling to develop the ScreeningLimits and dispersion modeling isavailable as the exposure assessmentcomponent of the site-specific riskassessment option. A more extensivediscussion of air dispersion modeling isincluded in the 1989 supplemental notice(see 54 FR 43752-54). This discussionfocuses on derivation of ScreeningLimits wherein the dispersion modelsare used to "back-calculate" emissionrates from acceptable ground levelconcentrations. The section is alsoapplicable to dispersion modeling usedfor the risk assessment option (whereground level concentrations arepredicted from estimated emissionsrates). The reader is referred to thisdiscussion for further information about

air dispersion modeling. It should benoted that for the purposes of the riskassessment option, more site-specificinformation may be used in place ofsome of the conservative defaultassumptions used to derive theScreening Limits, generally resulting inlower predicted ambient airconcentrations.

1. Option for Site-Specific Modeling

In responding to this provision in theproposal, mAny commenters argued forprocedures which would allow greaterflexibility in the air dispersion modelingprocess. Many commenters seemed toconfuse the issues of dispersionmodeling used for the Screening Limits,and modeling for the site-specific riskassessment. EPA concedes that manyassumptions used to develop theScreening Limits are, by design,conservative to ensure that the Limitsare protective in most cases. Theseassumptions do not apply, however,when an owner or operator conductssite-specific dispersion modeling underthe Tier III standards. For site-specificdispersion modeling, proceduresspecified in EPA's Guideline on AirQuality Models must be used.

2. Terrain-Adjusted Effective StackHeight

Two commenters stated that inadjusting the stack height to account forlocal terrain and differentiating forterrain in the screeing limits, EPA is"double counting" the influence ofterrain unnecessarily. One commenteradded that such terrain adjustment ofstack height is not supported by thecurrent EPA Guideline on Air QualityModels (Revised) and should beeliminated.

EPA acknowledged this "doublecounting" of terrain in the supplement tothe proposed rule (54 FR 43759], statingthat this additional conservatism isnecessary to account for the wide rangeof terrain complexities encountered atreal facilities. EPA continues to believethat this double counting is necessary.Without this conservatism, additionalcriteria would have to be added to theexisting list (see § 266.106(b)(7)) fordetermining when the screening limitsmay not be conservative and, thus, maynot be used. Commenters did notpropose (and provide support for)additional criteria for determining whenthe use of less conservative screeninglimits would be appropriate. Further,EPA believes that additional criteriawould complicate and delay theimplementation of the rule by placingadditional burden on regulatoryofficials. Moreover, if a facility cannot

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meet the screening limits, then site-specific dispersion modeling may beused to demonstrate compliance withthe Tier III standards. Detailed,comprehensive dispersion modelinggenerally costs less than $5,000 and,thus, should not pose a substantialburden. In fact many BIFs have alreadyconducted such modeling to complywith applicable standards under theClean Air Act. Finally, the final ruleminimizes the burden of dispersionmodeling by allowing the use ofscreening models.

3. Conservatism in Screening LimitsFive commenters stated that EPA's

approach to setting the screening limitsis overly conservative and illustratedthis by calculating the difference inestimated ground level concentrationsusing site-specific information asopposed to the default assumptionsrecommended for the Screening Limits.

It should be noted that the Agencywould expect that the use of site-specific information would lead tohigher emission limits than under thescreening limits. However, the Agencydeveloped feed rate and emission ratescreening limits with the intent ofminimizing the need of site-specificdispersion modeling and thus reducingthe burden of demonstrating compliancewith the emissions standards. To ensurethat the limits are protective in mostcases, however, the Agency derived thelimits using conservative assumptions.The Agency believes that, although theassumptions are reasonable, they wouldlikely limit emissions by a factor of 2 to20 times lower than would be allowedby site-specific dispersion modeling (54FR 43758).

4. GEP Stack Height.Two commenters stated that EPA

should not impose a GEP stack heightlimitation for existing stacks. Thecommenters went on to state that EPAshould allow modeling of emissions atactual stack height for existing stacksor, at a minimum, adopt a grandfatherprovision to exclude GEP from applyingto stacks constructed prior to December31, 1970. One commenter also indicatedthat EPA should recognize that the stackheight used for conducting a site-specificdispersion modeling analysis mayexceed GEP formula height, as allowedunder section 123 of the Clean Air Act.

The Agency maintains that incomplying with the metals and HCl/C 2controls credit will not be allowed forstack heights greater than GEP. GEPstack heights are determined in amanner consistent with the Guidelinefor Determination of Good EngineeringPractice Stack Height (Technical

Support Document for the Stack HeightRegulations), Revised (EPA 450/480-023R).

EPA's position here is consistent withthe prohibition on using physical stackheight in excess of GEP in thedevelopment of emission'limitationsunder EPA's Air Program at 40 CFR51.118 and 40 CFR 51.164. Stack heightshigher than GEP cannot be used forcompliance purposes because suchstacks merely provide added dispersionand dilution of ambient levels. EPAprefers that pollutants be removed fromthe stack gas to avoid build-up ofpersistent pollutants (e.g., metals in theenvironment and subsequent indirectexposure through, for example, the foodchain. In addition, better dispersion ofemissions of carcinogenic compoundscan merely expose larger populations to(albeit lower) concentrations ofpollutants and may not decrease theaggregate population risk (i.e., cancerincidents/year in the affectedpopulation).

5. Plume Rise Table

One commenter recommended thatEPA extend Table F-2 (plume rise) andTables E-1 through E-10 (feed rate andemissions screening limits) of theOctober 26, 1989 supplemental notice toaccount for the high flow rates typical ofmany cement plant stacks. Anothercommenter stated that the effectivestack height of most utility boilersexceeds the maximum stack heightcontained in Tables E-1 through E-10.One commenter indicated that theplume rise values presented in Table F-2 are not conservative for conditions ofneutral atmospheric stability at averageto high wind speeds or for stableatmospheric conditions at all typicalwind speeds. This commenter addedthat the screening limits based on TableF-2 plume rise may not be conservativefor regions having complex terrain.

For the final rule, the plume risevalues presented in Table F-2 of thesupplement to the proposed rule wererevised and the table was expanded toinclude higher stack exit flow ratesindicative of cement kiln stacks (exitflow rates were increased up to a levelof 200 m3/s). See appendix VI to thefinal rule. The plume rise table valueswere originally developed based onplume rise equations presented in the1979 User's Guide to the IndustrialSource Complex (ISC) model. The plumerise formulation in the ISC model hassince been changed to correspond to theway other EPA models determine plumerise. Consequently, the entire table wasrevised, based on conservativeapplication of the updated neutral and

stable buoyant plume rise equations. 51

The revised values of plume riserepresent the lowest value ofconservative stable buoyant and neutralbuoyant plume rise for each flow rate/temperature level.

The range of terrain-adjusted effectivestack heights, shown in Tables E-1through E-10 of the supplemental notice,was not increased beyond the height of120 meters. This height was determinedto be the maximum terrain-adjustedeffective stack height based on the stackparameter and site location data used inthe development of the dispersioncoefficients (as described in appendix Fof the proposed, supplemental rule).Facilities with terrain-adjusted effectivestack heights that exceed 120 metershave the option of conducting site-specific dispersion modeling todemonstrate compliance.

6. Compliance by Manipulating EffectiveStack Height

One commenter claimed that facilitiesmay elect to circumvent compliance bymanipulating their effective stackheights. This commenter added thatadditional exposures could result fromthe increased dispersion from tallerstacks. The Agency acknowledges thatan owner or operator could increasephysical stack height up to the GEPmaximum to achieve better dispersionand hence a higher allowable emissionrate. The Agency maintains, however,that it is more protective of humanhealth and the environment (seediscussion in section III.B.4 above) andit may be more cost-effective to upgradeemission control equipment to state-of-the-art control, rather than to increasestack height, particularly given that theAgency plans to consider in the futurewhether additional controls are neededto better control metals emissions. Seediscussion in section I of Part Three ofthis preamble.

7. Effect of HCl Emissions on Acid Rain

One commenter disagreed with theuse of Screening Limits for HCI whichare based solely upon effective stackheight, terrain and land use. Thiscommenter maintained that thisapproach ignores the effects of HCl inatmospheric reactions and acid rain.

Addressing potential effects of HCI inatmospheric reactions and acid rain isbeyond the scope of this rule. Thescreening limits were developed to

a' Memorandum from Sue Templeman, RadianCorp., to Dwight Hlustick. EPA, entitled "Derivationof Plume Rise Values for BIFs", dated November 30.1990.




protect human health in the vicinity offacilities burning hazardous waste.

8. Building Wake EffectsOne commenter stated that emissions

limits based on effective stack height,terrain, and land use would not beconservative in cases where stacks aresubject to building wake effects. Thiscommenter added that onlyconsideration of building wake effectswill lead to conservative concentrationsfor stacks influenced by nearbystructures and recommended that site-specific dispersion modeling be requiredin all cases where the "Guideline for AirQuality Models (Revised)" indicates thenecessity for consideration of buildingwake effects.

The development of the conservativedispersion coefficients incorporated aneleventh hypothetical source in order torepresent facilities whose releaseheights do not meet good engineeringpractice and whose plumes would thusbe subject to building wake effects (54FR 43752). In addition, the Agencyacknowledges that the dispersioncoefficients used to establish the Tier Iand II Screening Limits may not beconservative in extremely poordispersion conditions or when theambient-air receptor is located close tothe source and has therefore definedfive situations for which the permitwriter should require site-specificdispersion modeling (54 FR 43754).Furthermore, the Agency is reserving theright to require that a site-specificdispersion modeling analysis beconducted, irrespective of whether thefacility meets the specific ScreeningLimits. Thus, the permit writer has theoption of overruling use of Tier I or II, ifa probability exists that application ofthis methodology would not beprotective of the health-basedstandards. The Tier III approach ofconducting site-specific dispersionmodeling requires incorporation ofbuilding wake effects, as necessary, inthe modeling analysis. The Tier I and IIScreening Limit methodology was notfurther modified to account for thesefactors, as it already embodies repeateduse of conservative assumptions.

C. Consideration of Indirect Exposureand Environmental Impacts

1. Indirect Exposure

During the proposal stages of theseregulations, a few commentersrecommended incorporating indirectexposure pathways into the riskassessment process. Indirect exposure isdefined, in these regulations, as anyexposure pathway other than directinhalation of emissions from a boiler or

industrial furnace. One commentermaintained that emissions such asmetals, chlorinated dioxins, and furanswould be environmentally persistentand able to enter the food chain afterdeposition on the ground (includingcrops, pasture land, surface waters).Consequently, the commenter arguedthat indirect exposures should befactored into the risk assessment.

EPA recognizes that the contributionof indirect pathways may be significant.However, the Agency believes that otherconservative procedures, such asapportioning 75% of exposures to eitherindirect pathways or other emissionsources (that can contribute tobackground levels) in the calculation ofRACs, will help offset the contributionof indirect pathways. Anothersignificant source of conservatism,offsetting the contribution of indirectpathways, is represented by the inherentuncertainty, and consequentconservatism, in the models used toestimate unit risk values. Use of the MEIin the Screening Limits procedurecomprises yet another conservativeelement in the risk assessment processwhich would offset direct estimation ofindirect pathway exposure. Therefore,the Agency has not modified the riskassessment process to address indirectpathways.

2. Non-human Health RelatedEnvironmental Impacts

One commenter noted that for manypollutants, environmental standards forcertain flora and fauna may be morestringent than for humans. Therefore,the effect on non-human receptorsshould not be ignored in the regulationsand the environmental risks should beevaluated.

EPA is concerned about the potentialeffects of BIF emissions on non-humanreceptors. While some environmentalstandards are available for theprotection of environmental receptors(notably EPA water quality criteria foraquatic organisms), methods forquantifying exposure and definingacceptable levels for non-humanreceptors are still largely in thedevelopmental stages. Thus, until thesecritical procedures are betterestablished, the Agency is not requiringsuch an evaluation at this time.However, as noted earlier, some of theconservatism in the human health riskassessment is designed to compensatefor the absence of direct environmentalstandards.

D. Acceptable Risk Level forCarcinogens

Today's rule limits the incrementallifetime cancer risk to the hypothetical

maximum exposed individual (MEI) to10 - . This risk level is within the rangeof levels historically used by EPA in itshazardous waste and emergencyresponse programs-10

- 4 to 10- .

Under the rule, we are limiting theaggregate risk to the MEI fromcarcinogenic metals to 10 - , and theaggregate risk from carcinogenic organiccompounds (dioxins and furans andother PICs under provisions of thealternative HC limit) to 10 - . This willlimit in most cases the risk fromindividual carcinogenic compounds tolevels on the order of 10-6 but below10 - . The rule does not require that therisk from carcinogenic organiccompounds be added to the risk fromcarcinogenic metals. This is because theAgency does not believe it isappropriate to sum the risk from metals(i.e., arsenic, beryllium, cadmium, andchromium) that are known or probablehuman carcinogens (Group A or Bcarcinogens under the weight-of-evidence approach) with the risk fromorganic compounds, many of which arepossible human carcinogens (Group Ccarcinogens).

In selecting a 10- 5 aggregate riskthreshold level for this rule, weconsidered risk thresholds in the rangeof 10 - to 10-6, the range the Agencygenerally uses for various aspects of itshazardous waste programs.

We considered limiting the aggregaterisk of the MEI to 10-6but determinedthat this risk threshold would beunnecessarily conservative for thepurpose of this rule. In reaching thisdetermination, we considered that, at anaggregate risk level of 10- 6, the risk levelfor individual metals would be on theorder of 10- 7, which we believe is overlyconservative for this rule.

Alternatively, we considered limitingthe aggregate risk to the MEI to 10-. Anaggregate risk threshold of 10-' Wouldresult in limiting the risk level forindividual carcinogens on the order of10- . We did not select a 10-' aggregaterisk thieshold for this proposed rule fora number of reasons. In selecting theappropriate risk level for a particularregulatory program, the Agencyconsiders such factors as the particularstatutory mandate involved, nature ofthe pollutants, control alternatives, fateand transport of the pollutant indifferent media, and potential humanexposure. The Agency believes that a10- 1 risk level is appropriate for this rulebecause: (1) The rule limits emissionsconsidering only direct exposure viainhalation of dispersed emissions. Otherroutes of exposure (e.g., soil ingestion,uptake through the food chain) are notaccounted for by this methodology,

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which means the risk is somewhathigher; (2) the carcinogenic metals thatthe rule controls are Group A or B (i.e.,known or probable) human carcinogens;(3) we are concerned about the potentialrisks posed by the unknown pollutantsthese devices can emit-i.e., products ofincomplete combustion (PICs);52 and (4)the 10 - 5 risk level does not result in arule that poses a substantial burden onthe regulated community given that it isneither a major rule as defined byExecutive Order 12291 nor will itsignificantly impact small entities.

When the proposed regulations werepublished and comments were solicitedfrom affected parties, severalcommenters responded to the issue ofacceptable risk levels for exposure tocarcinogens. These commentersquestioned the basis of 10- 5 asrepresenting an acceptable risk level.They maintained that the discussion inthe rule, serving as the rationale orjustification for selecting this level ofrisk, was inadequate. Others assertedthat the selected acceptable level ofcancer risk was not consistent withother regulations (specifically, 10-- 4

cancer risk to the MEI was used to set anational emission standard (NESHAP)for benzene, and 10- 5 for individualsliving "some distance from the source").

The Agency continues to believe thatthe aggregate cancer risk to the MEI of10- 5 is appropriate here because: (1) Itprovides adequate protection of publichealth; (2) it limits the risk fromindividual Group A and B carcinogens torisk levels on the order of 10- s; and (3) itis within the range of risk levels theAgency has used for hazardous wasteregulatory programs. See also discussionin section Ill.A above.E. Use of MEI/Consideration ofAggregate Risk

The Agency considered the use ofaggregate population risk or cancerincidence (i.e., cancer incidents peryear) in developing the nationalemission limits and in site-specific riskassessments. This approach could, insome situations, be more conservativethan considering only MEI risk because,even if the "acceptable" MEI risk levelwere not exceeded, large populationcenters may be exposed to emissionssuch that the increased cancer incidencecould be significant. However, it wouldbe difficult to develop acceptableaggregate cancer incidence rates.Nevertheless, it is likely that manyfacilities that perform a site-specific MEIexposure and risk analysis would also

5 2 This rule is, thus, unlike the Benzene NESItAPwhere EPA targeted one known pollutant willknown effects.

generate an aggregate populationexposure and risk analysis that could beconsidered by the Agency.

Several commenters addressed theissue of using the maximum exposedindividual (MEI) as a basis for riskestimation and recommended usingpopulation (aggregate) risks as a morerealistic alternative. They maintainedthat health risks are overstated if basedonly on exposure of the MaximumExposed Individual (MEI). Aggregatepopulation-based exposures, which areusually much lower would morerealistically represent site-specifichealth risks. Many commenters notedthat using the MEI exposure implicitlyassumes that population risks aresimilar.

EPA believes that evaluation of theMEI only (and not aggregate populationrisk) is usually a conservative feature ofthe risk assessment. For screeningpurposes, a simplified approach isnecessary. While site-specificdemographic data is usually readilyavailable from 1980 census data, itsincorporation into a screen wouldcomplicate the screening processunnecessarily. Calculation of screeninglimits based on the risks to the MEIrequires much less site-specificinformation, facilitating application ofthe screen to a broad range of sites. Ifthe facility does not meet the screeninglimits, the option of site-specific riskassessment is still available. While MEIexposures are estimated routinely in asite-specific risk assessment, aggregatepopulation risks may also be estimated,if desired.

Several commenters also contendedthat even the risk estimates for the MEImay be overly health-protective sincethe MEI is assumed to reside at this highexposure location 24 hours per day, 365days per year, for a 70-year lifetime. Amore fair evaluation of MEI risk wouldaccount for the attenuating effects oftime spent indoors and off-site, andinclude estimates of average residencetimes and facility lifetimes. Moreover,some exposure assessments assume theMEI is located at the point of maximumground level concentration predicted bythe dispersion model, when in fact, noone may live at this site.

EPA acknowledges that use of thehypothetical MEI is a conservativefeature of the rule but maintains that itis reasonable to balance against thepotentially nonconservative features ofthe rule discussed below.F. Risk Assessment Assumptions

As indicated in the above discussion,we have used a number of assumptionsin the risk assessment, someconservative and others

nonconservative, to simplify theanalysis or to address issues wheredefinitive data do not exist.

Conservative assumptions include thefollowing:

e Individuals reside at the point ofmaximum annual average ground levelconcentrations. Furthermore, riskestimates for carcinogens assume thatthe maximum exposed individualresides at the point of maximum annualaverage concentration for a 70-yearlifetime.

e Indoor air contains the same levelsof pollutants contributed by the sourceas outdoor air.

* For noncarcinogenic healthdeterminations, background exposurealready amounts to 75% of the RfD. Thisincludes other routes of exposure,including ingestion and dermal. Thus,the BIF is only allowed to contribute 25%of the RfD via direct inhalation. Theonly exception is for lead, where a BIF isonly allowed to contribute 10% of theNAAQS. This is because ambient leadlevels in urban areas already representa substantial portion (e.g., one-third ormore) or the lead NAAQS. In addition,the Agency is particularly concernedabout health risks from lead in light ofhealth effects data available since thelead NAAQS was established. EPA iscurrently reviewing the lead NAAQS todetermine if it should be lowered.

* Risks are considered for pollutantsthat are known, probable, and possiblehuman carcinogens.

* Individual health risk numbers havelarge uncertainty factors implicit in theirderivation to take into effect the mostsensitive portion of the population.

Nonconservative assumptions includethe following:

* For carcinogenic compounds,indirect routes of exposure are notconsidered, such as uptake of arsenic,beryllium, cadmium, and chromiumthrough the food chain.

a Although emissions are complexmixtures, interactive effects of thresholdor carcinogenic compounds have notbeen considered in this regulationbecause data on such relationships areinadequate.

* Environmental effects (i.e., effectson plants and animals) have not beenconsidered because of a lack ofadequate information. Adverse effectson plants and animals may occur atlevels lower than those that causeadverse human health effects. (TheAgency is also developing proceduresand requesting Science Advisory Boardreview to consider environmentaleffects resulting from emissions from all




categories of waste combustionfacilities.)

Many commenters responded broadlyon the impact of assumptions anduncertainty in risk assessment. Whilegenerally supporting the concept of riskassessment, some asserted that EPA'sproposed assumptions were tooconservative regarding estimatedemission levels, dispersion modeling,and health impact estimation. Further,they maintained that assumptions werenot well enough justified and theconservative bias used for each of themultiple assumptions required in a riskassessment tends to accumulate,resulting in gross over-estimation ofhealth impacts. Some of the specificassumptions that commentersconsidered too conservative arediscussed in the following paragraphs.

Two commenters asserted thatemission control technology should notbe assumed absent when estimatingemission levels. One commenterrecommended that sensitivity analysisbe incorporated into the risk assessmentprocess. This commenter alsorecommended incorporation into the riskassessment of population mobility (i.e.,time spent away from the site), facilitylifetimes less than 70 years, and anattenuation factor for time spentindoors, rather than assume 24 hr/day,70-year exposure.

Many of the respondents argued thateconomic impacts resulting from overly-conservative risk assessments aresubstantial. To avoid some of thedefault assumptions is also burdensomein the commenters' judgment requiringtrial burns, emissions measurements,slag and product assays, and detailedair quality dispersion modeling.

Although many of the assumptionsdiscussed by the commenters areconservative in nature, it is difficult todetermine how less conservativeassumptions could be used in light of theconsiderable associated uncertainty.Much of the conservatism referred tooriginates from assumptions used toderive screening levels. When screeninglevels are derived, either: (1) No site-specific information is available (normay be assumed if the procedure isintended to screen a variety of sites); or(2) incorporation of site-specificinformation in the derivation ofscreening levels would so complicatethe process as to render it prohibitivelytime-consuming and defeat its utility asa screen. Thus, in light of the uncertainty(i.e., no site specific-information),conservative assumptions are used toderive the screening limits that EPAbelieves to be protective of humanhealth and the environment.

If the facility fails to meet thescreening criteria, the option of site-specific risk assessment is stillavailable. For site-specific riskassessment, more realistic and lessconservative assumptions may beincorporated, reflecting actual site orfacility conditions.

V. Controls for Emissions of ToxicMetals

The Agency has identified 12 toxicmetals in appendix VIII of 40 CFR part261 that may pose a hazard to humanhealth and the environment: antimony,arsenic, barium, beryllium, cadmium,hexavalent chromium, lead, mercury,nickel, selenium, silver, and thallium.Five of these metals (or theircompounds) are known or suspectedcarcinogens: arsenic, beryllium,cadmium, hexavalent chromium, andnickel.

Many of these toxic metals arecontained in hazardous waste that isburned in boilers and industrialfurnaces. Many hazardous waste fuelscontain metals at levels orders ofmagnitude higher than levels found inNo. 6 fuel oil. Metal-bearing wastestypically used as fuel in boilers andindustrial furnaces Include spenthalogenated and nonhalogenateddegreasing solvents used for metalscleaning, paint manufacturing wastes,and other organic liquid wastes withhigh heating values. Currently, metalsemissions from the burning of thesewastes are not controlled under RCRAfor boilers and the types of industrialfurnaces that burn hazardous wastes.Emissions of carcinogenic metals canpotentially result in increased lifetimecancer risks of greater than I X 10- 4 andemissions of noncarcinogenic metalssuch as lead can result in ambient levelsthat result in adverse health effects.

Today's final rule promulgates thecontrols as discussed in the October1989 supplement to the proposed rule(see 54 FR 43728-29).53 See § 266.106.The rules establish metals emissionlimits for 10 toxic metals) 54 listed in

63 Given time constraints in developing the finalrule for promulgation, response to major commentscould not be provided in the preamble. Responses tocomments are provided in the Comment ResponseDocument for the BIF Regulation.

64 As proposed, the rule does not limit emissionsof nickel and selenium (see 54 FR 43729). Limitscannot be established for selenium because theAgency has inadequate health data to establish areference air concentration. Nickel Is not controlledbecause the two nickel compounds suspected at thistime of being potential human carcinogens, nickelcarbonyl and subsulfide, are not likely to be emittedfrom combustion devices, given their highlyoxidizing conditions. In the 1989 supplementalnotice to the proposed rule, EPA requestedcomments on whether the reduced carcinogenicforms of nickel were likely to be emitted from

appendix VIII of 40 CFR part 261 basedon projected inhalation health risks to ahypothetical maximum exposedindividual (MEI). The standards for thecarcinogenic metals (arsenic, beryllium,cadmium, and chromium) limit theincreased lifetime cancer risk to the MEIto a maximum of 1 in 100,000. The riskfrom the four carcinogens must besummed to ensure that the combinedrisk is no greater than 1 in 100,000. Thestandards for the noncarcinogenicmetals (antimony, barium, mercury,silver, and thallium) are based onReference Doses (RfDs) below whichadverse health effects have not beenobserved. The standard for lead isbased on ihe National Ambient AirQuality Standard (NAAQS) for lead.

The owner and operator must analyzethe hazardous waste to be burned andcomply with the standard for each of the10 metals that could reasonably beexpected to be in the waste. The metalsexcluded from analysis must beindentified and the basis for theirexclusion explained to ensure that thereis adequate justification for notanalyzing for a particular metal.

The standards are implementedthrough a three-tiered approach.Compliance with any tier is acceptable.The tiers are structured to allow higheremission rates (and feed rates) as theowner or operator elects to conductmore site-specific testing and analyses(e.g., emissions testing, dispersionmodeling). Thus, the feed rate limitsunder each of the tiers are derivedbased on different levels of site-specificinformation related to facility designand surrounding terrain. Under tier I(see § 266.106(b)), the Agency hasprovided conservative waste feed ratelimits in reference tables as a function ofeffective stack height and terrain andland use in the vicinity of the stack. Theowner or operator demonstratescompliance by waste analysis, notemissions testing or dispersionmodeling. Consequently, the Tier I feedrate limits are based on an assumedreasonable, worst-case dispersionscenario, and an assumption that allmetals fed to the device are emitted (i.e.no partitioning to bottom ash or product,and no removal by an air pollutioncontrol device (APCD).

Under Tier II (see § 266.106(c)), theowner or operator conducts emissionstesting (but not dispersion modeling) toget credit for partitioning to bottom ash

hazardous waste burning devices, especially thosefurnaces that may not use highly oxidizedconditions. However, the Agency did not receiveany comments on this issue pertinent to boilers andindustrial furnaces.

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or product, and APCD removalefficiency. Thus, the Agency hasdeveloped conservative emission ratelimits in reference tables, again as afunction of effective stack height andterrain and land use in the vicinity of thestack. The Agency also assumedreasonable, worst-case dispersion underTier II.

Under Tier III (see § 266.106(d)), theowner or operator elects to conductemissions testing and site-specificdispersion modeling to demonstrate thatthe actual (measured) emissions do notexceed acceptable levels consideringactual (predicted) dispersion.

The metals controls apply both tofacilities applying for a part B operatingpermit and to facilities operating duringinterim status. See section VII of partThree of this preamble for discussion ofhow the standards apply during interimstatus.

A. Background Information

The following sections summarizeEPA's regulation of metals emissionsfrom boilers and industrial furnacesunder other statutes, the 1987 proposedrule and comments received on thatproposal, and the basis for the 1989revision to the proposed rule andcomments received on that revisedapproach.

1. Metal Standards Under Other Statutes

As discussed below, EPA haspromulgated standards applicable toboilers and industrial furnaces underother statutes for some but not all of the10 toxic metals controlled by today'srule. Under the Clean Air Act (CAA),EPA established National EmissionsStandards for Hazardous Air Pollutants(NESHAPS) for arsenic, beryllium, andmercury for certain categories of sources(40 CFR part 61). These emissionstandards were developed consideringthe quantities and types of metalsemissions from various sourcecategories, current control practices, andthe economic impacts of reducingemissions. In addition, EPA hasestablished National Ambient AirQuality Standards 55 (NAAQS) for leadand particulate matter. These ambientstandards are implemented by statesunder the State Implementation Plan(SIP) program to control major sourcesof lead and particulate emissions. TheAgency does not believe that leademissions standards have been

" We note that the reference air concentrationvalues for noncarcinogens and risk-specific dosevalues for carcinogens established by today's ruleare not intended to, and in no way, preclude theAgency from establishing NAAQS as appropriatefor these compounds under authority of the CleanAir Act.

established under the SIPs for anyboilers and for many industrial furnacesthat burn hazardous waste fuels (e.g.,cement and light-weight aggregate kilns)because they are not major lead emittersas defined under the NAAQS. Therefore,EPA believes that today's metalscontrols are not redundant to existingAgency standards, and, thus, arenecessary to ensure adequate protectionof human health and the environment.

Particulate emission standards,however, established under the SIPs inconformance with the particulate.NAAQS, or by EPA as New SourcePerformance Standards (NSPS), doapply to some boilers and industrialfurnaces that burn hazardous waste.The particulate standards generally limitmetals emissions to the extent thatstate-of-the-art particulate controltechnologies will allow. High efficiencyelectrostatic precipitators (ESPs) orfabric filters are usually required tomeet these standards. However, theseparticulate emission standards may notadequately control metals emissionsfrom the burning of hazardous wastes inmany boilers and industrial furnaces forservice reasons: (1) The particulatestandards do not apply to gas and oil-fired boilers (which represent a largenumber of hazardous waste fuelburners); (2) smaller coal-fired boilersare not subject to NSPS standards andmay not be required under the SIPs to beequipped with'ESPs or fabric filters; (3)large volumes of hazardous waste fuelsare burned by light-weight aggregatekilns that are equipped with low-pressure wet scrubbers that may not behighly efficient at collecting particulatesin the less than 1 micron range, the sizerange that contains the bulk of theparticulate metals; and (4) the risksposed by metals emissions from theseboilers and industrial furnaces that areequipped with ESPs, fabric filters, andwet scrubbers can increasesubstantially when hazardous wastefuel is burned since the levels of somemetals, particularly chromium and lead,can be much higher in hazardous wastethan in coal.

2. 1987 Proposed Rule

The 1987 proposed rule would haveestablished a four-tiered standard tocontrol emissions of arsenic, cadmium,hexavalent chromium, and lead. Eachtier represented a standard protectiveon its own, and demonstration ofcompliance with any Tier would havebeen sufficient. Tiers I through IIIestablished hazardous waste metalsconcentrations, feed rates, and emissionscreening limits, respectively, as afunction of device type and thermalcapacity. Tier IV would have provided

for site-specific dispersion modeling todemonstrate that, when the screeninglimits were exceeded, emissions wouldnevertheless not pose an unacceptablehealth risk. Data available to theAgency indicated that only four of the 12toxic metals listed in appendix VIII ofpart 261 were likely to be present inhazardous waste burned in boilers andindustrial furnaces at levels posing asignificant health risk. The permit writerwould have determined on a case-by-case basis if any of the other toxicmetals were present at levels posing asignificant risk.

Public comments submitted on the1987 proposal stated that EPA'sdatabase on the metals composition ofhazardous waste was both limited andout of date in light of the Agency's datacollection efforts at that time and theHSWA statutory requirement to pretreatwaste that heretofore had been landdisposed. As a result of HSWA, morehazardous waste is being burned, andpretreamtent operations are often likelyto involve combustion. The hazardouswaste burned currently and in the futurein boilers and industrial furnaces mayinclude toxic metals other than the fourtargeted for regulation in the 1987proposal. Therefore, the Agencyrequested comment in the October 1989supplemental notice on expanding thelist of regulated metals to include all 10appendix VIII metals. (Nickel andselenium were not included as discussedabove.) In addition, if standards for allof the toxic metals were included in therule, the burden on permit writers wouldactually be reduced because explicitstandards would be provided for allmetals of potential concern. Withoutexplicit standards, permit writers wouldhave to rely on the omnibus permitauthority of the statute to add permitconditions as necessary to protecthuman health and the environment.Using the omnibus permit authority caninvolve a lengthy and cumbersomeinteraction between permit officials andthe applicant.3. 1989 Supplement to Proposed Rule

Based on public comments submittedon the 1987 proposed rule and onadditional evaluation of the riskassessment approach used for theproposal, the Agency discussed in the1989 supplemental notice whether to (1)expand the list of metals for whichemissions standards would beestablished in the rule to include all thetoxic metals listed in appendix VIII ofpart 261 (except nickel and selenium, forthe reasons discussed above); (2)establish the screening limits as afunction of effective stack height,




terrain, and land use rather than as afunction of device type and capacity;and (3) rather than provide the screeninglimits in the rule itself as proposed in1987, provide them in a guidancedocument that would be entitled "RiskAssessment Guideline (RAG) forPermitting Hazardous Waste ThermalTreatment Devices".

a. Expanded List of Metals. In the1989 supplemental notice, EPA proposedto expand the list of metals for whichemissions standards would beestablished in the rule to includeantimony, arsenic, barium, beryllium,cadmium, hexavalent chromium, lead,mercury silver, and thallium. Thus, ofthe 12 toxic metals listed in appendixVIII, only selenium and nickel would notbe controlled for reasons discussedabove. Today's final rule establishesstandards for all 10 metals. We note thatthe controls apply only to metals thatare present in the hazardous waste feedat detectable levels using proceduresspecified in SW-846. See § 266.106(a).

b. Revised Basis for Screening Limits.In the 1989 supplemental notice, EPAalso proposed to revise the bases for thefeed rate and emission rate screeninglimits to correlate them with stackheight and terrain and land use in thevicinity of the facility because theseparameters more directly relateemission controls to key parameters thataffect the dispersion of emissions, andultimately, ambient levels (i.e., more sothan the proposed approach ofcorrelating the screening limits to devicetype and heat input capacity). Whendeveloping the Tier I through Tier Iscreening limits proposed in 1987, theAgency made a simplified assumptionthat effective stack height correlatedwith thermal capacity (e.g., if thethermal capacity of one device was 10percent greater than the thermalcapacity of another, the effective stackheight was also 10 percent greater). TheAgency acknowledges that thisassumption may not always hold. Stackheight is often more a function of theheight of nearby buildings andsurrounding terrain than a function ofthe heat input capacity of the device.Thus, the final rule correlates the Tier Iand Tier II screening limits to stackheight, terrain, and land use.

c. Establishing the Screening Limits inthe Rule. As originally proposed in 1987,the final rule incorporates the Tier I feedrate screening limits and the Tier IIemissions rate screening limits in therule itself rather than in a separateguidance document. Our concern (andmany commenters concurred) is that aguidance document would not carry theweight of a regulation-permit writers

would be free to accept or reject theguidance (i.e., in this case, the screeninglimits and the reference airconcentration (RACs) and risk-specificdose (RSD) values used to develop thelimits). In addition, permit writers wouldbe obligated to justify use andappropriateness of the guidance on acase-by-case basis. This would place asubstantial burden on the permit writerand result in inconsistent, and perhaps,inappropriate permit conditions. Finally,implementing the emission standardsduring interim status as required by thefinal rule would be virtually impossiblewithout incorporating the screeninglimits and RACs and RSDs in the rule.

We note that revisions to the RACsand RSD values will undoubtedly needto be made over time as the Agencyobtains additional health effectsinformation on the regulated pollutants,and corresponding revisions to thescreening limits will be made by formalrulemaking (i.e., proposed revisions,opportunity for public comment, andpromulgation of final revisions). In theinterim, however, permit writers mayapply stricter limits than contained inthe rule (if the facts justify it) pursuantto the omnibus permit authority 56 insection 3005(c)(3).

In the 1989 proposal, as a possiblealternative to monitoring waste feedrates and compositions, EPA requestedcomment on using the results ofanalyses of emission control residues tomonitor compliance with the metalsemission standards. Severalcommenters supported this approach.The final rule allows for this or otheralternative approaches to implement themetals controls. See section IV.C.4 ofPart Three of the preamble.

B. How the Standards Work

1. Tier I StandardsTier III standards are discussed first

because the Agency believes that themajority of facilities will elect to complywith these standards rather than theTier I or Tier II screening limits to obtainmore flexible permit limits. The Tier IIIstandards (see § 266.106(d)) require: (1)Emissions testing to determine actualemissions taking into accountpartitioning of metals to combustion gasversus ash or product; and removal of

51 EPA notes 'hat permit writers choosing toinvoke the omnibus permit authority of§ 270.32(b](2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

metals from flue gas by the air pollutioncontrol system (APCS); and (2) site-specific dispersion modeling to take intoaccount actual, predicted dispersionconditions at the facility.

To comply with the Tier III standards,predicted ambient concentrations of thecarcinogenic metals, arsenic, beryllium,cadmium, and hexavalent chromium atthe hypothetical maximum exposedindividual (ME) may not result in anincreased cancer risk of more than 1 in100,000. The risk from each metal mustbe summed to ensure that the summedrisk does not exceed I in 100,000. Asproposed, the final rule establishes arisk-specific dose (RSD) for each metalat the 10- 5 (i.e., 1 in 100,000) risk level. Ifa person is exposed to the 10 - 5 RSD (anambient air concentration) over alifetime, the probability of increasedcancer incidence is not expected toexceed 1 in 100,000. To ensure that thesummed risk from the four carcinogensis no greater than I in 100,000, the ratiosof the predicted ambient concentrationto the 10 - 5 RSD must be summed for allmetals to demonstrate that the sum doesnot exceed 1.0.57

For the noncarcinogenic metals,antimony, barium, mercury, silver, andthallium, predicted MEI ambient airconcentrations may not exceed thereference air concentrations (RACs), asproposed. The RAC for lead is based on10% of the National Ambient Air QualityStandard (NAAQS) for lead, asproposed. One commenter stated thatthe lead RAC may be appropriate forfacilities in urban areas but that it is notappropriate for rural areas with lowbackground lead levels. This commentersuggested a waiver of the lead RACwhere a facility can show that measuredambient air lead levels do not exceedthe NAAQS. Although this approach isreasonable, the final rule does notinclude a waiver provision for the leadRAC based on site-specific ambient airmonitoring 58 because: (1) the lead

57 To implement the metalb controls, metals feedrates are limited to levels during the compliance testor trial burn. Thus, if the owner/operator would liketo have the flexibility to burn wastes with varying(higher) levels of carcinogenic metals, he/she maychoose to develop two or more operating modeswith varying feed rates of carcinogenic metals. If so,a compliance test or trial bum would be requi-ed fureach mode of operation to demonstrate that thesummed risk from the carcinogenic metals does notexceed 1 in 100,00. Under this approach, theoperator is required to identify the mode ofoperation at any time, end to comply with the metalfeed rate limits for that mode of operation.

68 We note, however, that EPA's Guideline on AirQuality Models allows the use of ambient airmonitoring to develop site-specific dispersionmodels.

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NAAQS may not be protective giventhat the Agency has been developing forsome time a proposal to lower theNAAQS (perhaps by as much as 50%)based on health effects data obtainedsince the NAAQS was establishedinitially (the Agency plans to propose alower lead NAAQS in the fall of 1991);(2) the time and cost of conductingambient monitoring in conformance withprocedures established by EPA's Officeof Air Quality Planning and Standards(OAQPS] would make this approachimpracticable; (3) a waiver provisionwould add extra complexity to the rule;and (4) such a waiver would makeeventual further regulation underamended section 112 of the Clean AirAct more likely.

a. Emissions Testing. Stack emissionstesting for metals must be conducted inconformance with "Methodology for theDetermination of Metals Emissions inExhaust Gases from Hazardous WasteIncineration and Similar CombustionProcesses" (Multiple Metals Train)provided in section 3.1 of MethodsManual for Compliance with the BIFRegulations (incorporated in today's ruleas appendix IX of part 266).

b. Dispersion Modeling. Dispersionmodeling must be conducted inconformance with EPA's "HazardousWaste Combustion Air QualityScreening Procedure" provided inMethods Manual for Compliance withthe BIF Regulations or EPA's Guidelineon Air Quality Models (Revised) whichare incorporated in today's rule asAppendices IX and X, respectively, ofPart 266, or "EPA SCREEN ScreeningProcedure" as described in ScreeningProcedures for Estimating Air QualityImpact of Stationary Sources. The latterdocument is incorporated by referencein today's final rule at § 260.11. TheGuideline on Air Quality Models is theAgency's primary guide for dispersionmodeling. The "Hazardous WasteCombustion Air Quality ScreeningProcedure" is included in EPA'sGuidance on Metals and HydrogenChloride Controls for Hazardous WasteIncinerators. Draft Final Report, August1989. The derivation of this procedure,which was developed specifically forhazardous waste combustion facilities,is also included in that document. Thedata base used in the derivation is thesame as that used for deriving the Tier Iand Tier II screening limits assummarized in the October 26, 1989supplement to the proposed BIF rule (54FR 43752). Finally, the EPA SCREENscreening procedure has been in generaluse since 1988 when it was developedby EPA's Office of Air Quality Planningand Standards. It has been used by

L

Regional Offices, States, and sources forair dispersion modeling required by EPAair regulations.

If a user determines that there is aninconsistency between either of thescreening procedures discussed aboveand EPA's Guideline on Air QualityModels, the Guideline shall haveprimacy.

c. GEP Stack Height. As proposed,stack heights used to demonstrateconformance with the final rule may notexceed Good Engineering Practice (GEP)as defined in 40 CFR part 51.100(ii).

d. ME. As proposed, the hypotheticalMEI concentration is the maximumannual average ground levelconcentration at an off-site location. On-site MEI locations need not be used todemonstrate conformance with thestandards, unless a person resides on-site.

e. Bubble Approach for MultipleStacks. Given that the standards formetals (and HCI and Ch) are health risk-based, the final rules are implementedusing a limited "bubble" approach asproposed. Under the limited bubbleapproach, emissions from all hazardouswaste combustion stacks at a facilitysubject to metals and chlorine feed ratelimits must be considered indemonstrating conformance with theacceptable ambient levels. This includesall boilers and industrial furnacesregulated under today's rule, and alsothose RCRA-regulated incinerators andthermal treatment units where feed rateor emission limits have been establishedfor metals, chlorine, HCl, or C12 by EPA.(The Agency considered expanding thebubble to consider other stack emissionssuch as from nonhazardous wasteincinerators or process stacks, butbelieves that effective implementationwould be difficult given the differenttypes and levels of regulatory controland procedures applicable to a varietyof stack emission sources.)

To implement the bubble approach,dispersion modeling must consideremissions from all regulated stacks (seediscussion above) to predict themaximum annual average off-siteground level (i.e., MEI) concentration ofeach metal. The MEI location willgenerally vary for each metal.2. Tier II Standards

See § 266.106(c). The final ruleincorporates the Tier II emission ratescreening limits (see appendix I of thefinal rule) as presented in the 1989supplemental notice as a function ofterrain-adjusted effective stack height,and noncomplex versus complex terrainand urban versus rural land use in thevicinity of the facility. The limits wereback-calculated from the RACs and 10-

RSDs established by today's rule usingreasonable, worst-case dispersionscenarios. Conformance with the Tier IIemission rate screening limits isdemonstrated by emissions testing (i.e.,the facility's actual emissions arecompared to the maximum allowablescreening limits).

The methodologies for determiningterrain-adjusted effective stack heightand terrain type are established in§ § 266.106(b) (3) and (4), and themethodology for determining land use inthe vicinity of the stack are provided in"Simplified Land Use ClassificationProcedures for Compliance with Tier Iand Tier II Limits in Methods Manual forCompliance with the BIF Regulations(incorporated in today's rule asappendix IX of part 266).

a. Special Requirements forCarcinogens. We note that the Tier IIemission rate screening limits for thecarcinogen metals arsenic, beryllium,cadmium, hexavalent chromium, areback-calculated from the 10- RSD foreach metal. Thus, if the actual emissionrate of one of those metals was at theTier II screening limit, the resulting riskto the MEI is estimated to be 1 in100,000. Given that the rule requires thatthe summed risk for all carcinogenicmetals cannot exceed 1 in 100,000, theratios of the actual emission rate to theTier II allowable emission rate for all ofthe carcinogenic metals must besummed and the sum cannot exceed 1.0.

b. Bubble Approach for MultipleStacks. Although we believe that mostfacilities will use Tier III dispersionmodeling to demonstrate conformancewith the metals (and HCl and Cl2)controls when they have multiple stacksto obtain credit for actual dispersionconditions, Tier II (or Tier I) may beused. To use the Tier I feed rate limits orTier II emissions rate limits for multiplestacks, the owner/operator mustconservatively assume that allhazardous waste is fed to the sourcewith the worst-case stack (i.e.,considering dispersion). The worst-casestack must be determined from thefollowing equation 59 as applied to eachstack:K=HVT

where:K =a parameter accounting for relative

influence of stack height and plume rise;H=physical stack height (meters);V= stack gas flow rate (Ms/second); andT=exhaust temperature (Kelvin).

59 This equation was proposed at 54 FR 43762(Oct. 26,1989). It is derived from a similar equationon pp. 2-3 of Screening Procedures for EstimatingAir Quality Impact of Stationary Sources, EPA-450/4-88-010. August 1988.



Federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 f Rules and Regulations

The stack with the lowest value of K mustbe used as the worst-case stack.

c. Facilities Ineligible To Use the TierII (and Tier I) Screening Limits. Thescreening limits were back-calculatedfrom the RACs and 10 - 5 RSDsestablished by today's rule usingdispersion modeling scenarios that theAgency considers reasonable, worst-case dispersion scenarios. However,dispersion characteristics at a particularfacility may, in fact, provide worsedispersion of emissions than used tocalculate the screening limits.Consequently, the final rule, asdiscussed in the 1989 supplementalnotice, establishes criteria for facilitiesthat are ineligible to use the screeninglimits. See I 266.106(b)(7).

3. Tier I Standards

See § 266.106(b). The final ruleincorporates the Tier I feed ratescreening limits (see appendix I to therule) as presented in the 1989supplemental notice as a function ofterrain adjusted effective stack height,and noncomplex versus complex terrainand urban versus rural land use in thevicinity of the facility. Conformancewith the Tier I feed rate screening limitsis demonstrated by sampling andanalysis of all feed streams (hazardouswaste, other fuels, and raw materials).

By complying with the conservativeTier I feed rate screening limits,applicants burning hazardous wastewith very low concentrations of metalswould not have to conduct emissionstesting. The feed rate limits are back-calculated from the emission screeninglimits, assuming that all metals presentin feedstreams are emitted to theatmosphere. Thus, no metals areassumed to partition to the bottom ashor product, and no allowance is madefor removal of metals from the stack gasby an air pollution control system.Consequently, the Tier I feed ratescreening limits are equivalent to theTier II emission rate screening limitsand are provided in the same table inappendix I to the rule. (At proposal, thefeed rate and emission rate screeninglimits were provided in separate tablesbecause the Agency presented the limitsin different units-lb/hr (pound perhour) for feed rate limits, and g/s (gramsper second) for emission rate limits. Toavoid confusion and for simplicity,however, the final rule combines theTier I and II screening limits andpresents the limits in g/hr (grams perhour)).

The Tier I discussions above onspecial requirements for carcinogensalso applies to the Tier I feed rate limits.Thus, to demonstrate conformance with

the feed rate limits for the carcinogenicmetals, the sum of the ratios of theactual feed rate to the Tier I allowablefeed rate for all of the carcinogenicmetals must be summed, and the sumcannot exceed 1.0.

In addition, the Tier II discussionsabove on the bubble approach formultiple stacks and criteria for facilitiesthat are ineligible to use the screeninglimit apply to the Tier I feed ratescreening limits as well.

Finally, we note that the Tier I feedrate limits may be adjusted upward toreflect site-specific dispersion modeling.This is a hybrid of Tiers I and IIl. See§ 266.106(e). Under this approach, site-specific dispersion modeling may beconducted using the proceduresdiscussed above to back-calculateallowable emission rates for each metal.These allowable emission rates thenbecome the adjusted feed rate limits.Given that emissions testing is notconducted under this modified Tier Iapproach, no credit is given forpartitioning of metals to bottom ash orproduct, or removal by the air pollutioncontrol system.

C. ImplementationAs discussed above, EPA developed a

three-tiered standard to ensure thatmetals emissions do not pose anunacceptable risk to human health andthe environment. Tier I consists ofconservative feed rate screening limits,Tier II establishes conservative emissionrate screening limits, and Tier III allowsthe use of site-specific air dispersionmodeling to demonstrate compliance.The decision of which tier to usedepends on the physical characteristicsof the facility and surrounding terrain,on the anticipated waste compositionsand feed rates, and on the level ofresources available for conducting theanalysis. It is acceptable to use differenttiers to comply with the standards fordifferent metals.1. Tier I Implementation

The Tier I feed rate limits areimplemented by sampling and analysisas necessary and flow rate monitoringof each feedstream (i.e., hazardouswaste, other fuels, and raw materials) toensure that the total feed rate of eachmetal does not exceed the Tier I limit oneither an hourly rolling average orinstantaneous basis (i.e., at any time),except as provided for the carcinogenicmetals and lead as discussed below.

a. Special Procedures forCarcinogenic Metals. Given that, for thecarcinogenic metals, the sum of theratios of the actual feed rates to the TierI allowable feed rates cannot exceed 1.0,there are no fixed feed rate limits for

individual carcinogenic metals. Rather,the operator must ensure that on anhourly rolling average or instantaneousbasis (or as allowed below forcarcinogenic metals and lead) that themixture of carcinogenic metals fed intothe BIF does not exceed allowablelevels. To demonstrate conformancewith this standard, the operator must: (1)Know the concentration of metals ineach feedstream and the flow rate ofeach feedstream; (2) calculate on anhourly rolling average or instantaneousbasis (or as allowed below forcarcinogenic metals and lead) the sumof the ratios of the actual feed rate tothe allowable feed rate; and (3) ensurethat the sum of the ratios for allcarcinogenic metals (on an hourlyrolling average or instantaneous basis oras allowed below) does not exceed 1.0.

b. Averaging Periods. As discussed inthe 1989 supplemental notice, the finalrule provides an alternative averagingperiod to the hourly rolling average orinstantaneous basis for the carcinogenicmetals arsenic, beryllium, cadmium, andchromium, and for lead. For thesemetals, an averaging period not toexceed 24 hours (i.e., 24-hour rollingaverage) may be used provided that thefeed rate at any time (i.e.,instantaneously) does not exceed 10times the feed rate on an hourly rollingaverage basis. The Agency believes thatan averaging period greater than anhourly rolling average is reasonablegiven that the metals controls are basedon lifetime exposures. However, theAgency is concerned that averagingperiods greater than 24 hours may bedifficult to enforce. A ten-fold higheremission rate should not pose adversehealth effects from short-term exposuresfor the carcinogenic metals because the24-hour rolling average would notexceed the level that could pose a 10 - 5

health risk over a lifetime of exposureand the threshold (i.e., noncancer)health effect would not be likely atexposures only ten times higher than the10- 5 RSD. A ten-fold higherinstantaneous ambient level for leadshould not pose adverse health effectsgiven that the acceptable ambient levelfor long-term exposure to lead (i.e., thelead RAC) is based on only 10% of theNational Ambient Air Quality Standard.

We do not believe that a similarapproach for the other noncarcinogenicmetals would be appropriate given theuncertainty in the level of protectionprovided by the long-term acceptableambient (e.g., the RACs are based onoral RfDs converted I to I to inhalationvalues).

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2. Tier II Implementation

Conformance with the Tier II emissionrate screening limits is based onemissions testing (see section IV.B.I.a)using the Multiple Metals Trainprescribed in Methods Manual forCompliance with the BIF Regulations(incorporated in today's rule asappendix IX of part 266). The Tier IIemission limits are implemented bypermit limits on the followingparameters based on operations duringthe trial burn:

* Maximum feed rate of each metal intotal feedstreams (e.g., hazardous waste,raw material, other fuel), except asdiscussed below;

e Maximum feed rate of eachmetal intotal hazardous waste feedstreams;

a Maximum feed rate of each metal inall pumpable hazardous wastefeedstreams;

* Maximum feed rate of totalhazardous waste and pumpablehazardous waste;

* Maximum feed rate of chlorine intotal feedstreams;

* Maximum production rate inappropriate units (e.g., total heat input,pounds of steam produced, raw materialfeed rate);

* Maximum temperature at the inletto the air pollution control system(APCS);

* Maximum combustion chambertemperature; and

e Key parameters to ensure properoperation of the APCS.

The approach that must be used tomeasure these parameters and theapproach to establish limits on eachparameter based on trial burn data isspecified in I 266.102(e)(6).

In addition, the permit-must specifysampling and analysis procedures for allfeedstreams and all flow rates of allfeedstreams must be continuouslymonitored and recorded.

The final rule establishes limits onthese parameters because they canaffect metals emissions. The feed rate ofmetals in both total hazardous wastefeeds and pumpable hazardous wastefeeds is limited because the physicalform of the waste (e.g., solid vs liquid)can affect the partitioning of the metalbetween bottom ash (for a boiler).orproduct (for a furnace) and combustiongas entering the PM control system.Metals partition to the combustion gasmore readily when fired in a liquid orpumpable form.

The rule limits the metal feed ratefrom total feedstreams to account formetals in raw materials andnonhazardous fuels. When added to theemissions from hazardous waste,noncarcinogenic metals from these

sources can cause the MEIconcentration to exceed the thresholdlevel for health effects and carcinogenicmetals from these sources can cause theMEI concentration to exceed theincremental lifetime cancer risk limit forthe rule of 1 in 100,000. Thus, thesecontrols ensure that burning hazardouswaste does not result in unacceptablerisks.

The rule limits the chlorine feed ratebecause chlorine can increase thevolatility of metals, thus increasing therate of partitioning to the combustiongas and, in some cases, resulting insmaller metal particulates in flue gasthat can be more difficult to control witha PM collection system.

The rule limits the maximum capacityof the device to ensure that, during thecompliance test (under interim status) orthe trial burn (under a part B permitapplication) the device is feeding rawmaterials and nonhazardous fuels at arate that will not be exceeded after thecompliance test or trial burn. Thus, thegas flow rate and particulate loading aremaximized during the compliance test ortrial burn, which tests the ability of thePM collection system to control metals.

The rule limits the maximumtemperature at the inlet to the PMcollection system because temperatureaffects the volatility of a metal-somemetal species may be partially (ortotally in the case of mercury) in thevapor form at high temperatures at theinlet to the PM collection system-whichwill reduce the amount of the metalcollected. Limiting the inlet temperatureto that occurring during the compliancetest or trial burn will ensure that thetemperature cannot be increased laterwhich could result in an increase inmetals emissions.

Finally, the rule limits key operatingparameters of the PM air pollutioncontrol system to ensure that itcontinues to operate as efficiently as itdid during the compliance test or trialburn.

3. Tier III ImplementationConformance with Tier III is

demonstrated by emissions testing andsite-specific dispersion modelingshowing that ambient levels of metalsdo not exceed allowable levels. Permitlimits are established for the sameparameters as required for Tier I.

4. Special Requirements for Furnacesthat Recycle Collected ParticulateMatter

Metal emissions-are not feasiblymonitored on a continuous basis. Thus,some other-means of demonstratingcompliance is necessary. For most typesof BIFs, compliance is demonstratedby

monitoring feed rates of metals from allfeedstreams. EPA requested commenton whether approaches other thanmonitoring feed rates of metals may bemore appropriate to implement themetals controls. See 54 FR 43760 (Oct.26, 1989). A number of commentersarguedthat the material balanceapproach for implementing the metalscontrols was impractical andnonconservative for cement kilns. Thematerial balance approach for metalslimits the feed rate of each metal inthree types of feeds: (1) Pumpablehazardous waste; (2) total hazardouswaste; and (3) total feedstreams.Although limiting the feedTate of eachmetal in the total hazardous waste feedand the pumpable hazardous waste feedwas workable, commenters argued thatlimiting the feed rate of metals in totalfeedstreams was impractical for cementkilns because of the variety of rawmaterials they feed. Raw materials to acement kiln are a blend of severalcomponents including calcium sourcessuch as limestone, sea shells, marl, orchalk, silica sources such as clay, shale,slate, or sand, and iron sources such asiron ore or mill grindings. Theproportions of the components of theblend are changed frequently accordingto the type of cement desired and thecomposition of the sources. This canmake it very difficult to accuratelydetermine the metals feed rate in theblended raw materials.

Of even more concern to the Agency,however, is the fact that the materialbalance -approach is not likely to beconservative (i.e., protective) forfurnaces, like cement kilns, that recyclecollected PM back into -the furnace.Because the dust is recycled, anincrease in the feed rate of a metal inone of the feedstreams-such as spikingduring a compliance test (under interimstatus) or a trial bum (under a part Bpermit application)-leads to a gradualincrease in the concentration (and feedrate) of the metal in the recharged kilndust which leads to a gradual increasein the metal emissions. Several rechargecycles may be necessary for the kiln toreach steady state condition. Thus, untilthe system reaches equilibrium, metalsfeed rates do not correlate with metalsemissions.

EPAconsidered a number ofalternatives to address the problem thatthe recycled dust creates a system thatis out of equilibrium when a metal isspiked. We considered handling therecycled dust as another feedstream.Under this approach, the feed rate ofmetals in'the recycled dust would beconsidered along with those from otherfeedstreams. (Or alternatively, the feed




rate of metals in the recycled oust wouldbe considered as a fourth level of metalsfeed rate controls-that is, the feed rateof metals in pumpable hazardous waste,total hazardous waste, recycled dust,and total feedstreams would be limited.)We did not adopt this approachbecause: (1) The recycled dust is aninternal recycled stream so that limitson the recycled dust coupled with limitson other feedstreams would probablycorrelate with metals emissions in thekiln off-gas, but not necessarily withstack emissions; and (2) during anemissions test when metals are spiked,the system will not be in equilibriumand we do not know enough about metalbehavior in the system to determinewhether the metals feed rate in the dustwould be higher or lower after reachingequilibrium (i.,e., we did not knowwhether this approach would beconservative).

To address this concern that thematerial balance approach toimplementing metals controls is notlikely to be conservative (i.e., protective)for furnaces that recylce dust, today'srule requires owners and operators ofsuch devices to comply with one of threealternatives: (1) Daily monitoring ofcollected PM to ensure that metalslevels do not exceed limits that relateconcentration of the metal in thecollected PM to emitted PM; (2) dailystack sampling for metals; or (3]conditioning of the furnace system priorto compliance testing to ensure thatmetals emissions are at equilibrium withmetals feed rates. We discuss each ofthese procedures below.

We note first, however, that today'srule gives owners and operators theoption of selecting one of these methodsonly during interim status. The Directorwill determine under the part B permitapplication proceeding which of thesemethods (or whether another method)may be more appropriate on a case-by-case basis considering the facts. See§ 266.106(f). In addition, we note thatexperience with these methods duringinterim status may indicate the need torefine them for use under a RCRAoperating permit. Finally, we note thatthis provision of the permit standards isnot limited to furnaces that recyclecollected PM. (However, the methodsdiscussed below may be used duringinterim status only by furnaces thatrecycle collected PM.) The permitstandards provide this flexibilitybecause, although we believe that thesemethods (as they may be refined withexperience) or other methods thatadequately address the concernsdescribed below must be required forsystems that recycle collected PM, the

first two methods (i.e., monitoringcollected PM or daily stack sampling)may be preferable for other types ofdevices as well. This is because thesefirst two alternative methods addressnot only the special problem caused byrecycled PM but also the problem of thedifficulty (and imprecision) associatedwith limiting metals emission rates bythe material balance approach given thevariability of waste and raw materialmatrices and variability of theconcentrations of metals in feedstreams,a problem that also exists for thesefurnaces and will exist for other devicesas well.60

a. Monitoring Metals in Collected PM.This approach will control metalsemission rates by establishing limits onall of the parameters discussed abovefor implementing the Tier II and Tier IIIcontrols, except for limits on the feedrate of each metal in total feedstreams.In lieu of that parameter, the final rulelimits the concentration of each metal incollected PM. See "AlternativeMethodology for Implementing MetalsControls" in Method Manual forCompliance with the BI" Regulations(incorporated in today's rule asappendix IX of part 266). Theconcentration limit is calculated bydetermining the maximum allowableconcentration of each metal in theemitted PM and by empirically relatingthe concentration of the metal in theemitted PM to the concentration of themetal in collected PM (i.e., theenrichment factor). The maximumallowable concentration of each metalin the emitted PM is determined bydividing the allowable emission rate forthe metal in pounds per hour by theapplicable PM standard 61 in pounds perhour. The enrichment factor (i.e.,concentration of a metal in emitted PMdivided by the concentration incollected PM) is determined initially bya series of 10 emissions tests over a two-week period. Quarterly testing isrequired thereafter to determine if theenrichment factor changes substantially.If so, the series of 10 emissions testsmust be conducted again to establish therevised enrichment factor.

EPA acknowledges certain potentiallimitations to this approach: (1) TheAgency has limited data to support themain assumption of this approach-thatthe enrichment factor will remainconstant over the range of normal

6s We also note that these methods may bepreferable to the material balance approach in somesituations for implementing the metals controls forhazardous waste incinerators.

6 The applicable PM standard is 0.08 gr/dscf orany more stringent standard that may apply underthe NSPS or SIP.

operating conditions that occur betweenthe initial series of 10 tests to establishthe enrichment factor and the quarterlyconfirmation tests; and (2) that aproblem with emissions is detected afterthe fact. However, we have built into theapproach conservative features thatshould address concern about whetherthe enrichment factor may change overtime. First, the approach assumes thatthe facility is always operating at itsmaximum allowable PM emission limit.Although allowable metalconcentrations in collected PM would behigher when the facility operates atlower PM emission levels, the limits donot change. Thus, for example, for every10% the facility operates under its PMstandard, the limit on metalsconcentrations in collected PM areconservative (lower than necessary) by10%. Second, the enrichment factor isstatistically determined based on testdata as the lower of: (1) Twice theenrichment factor at the 95% confidencelevel; or (2) the enrichment factor at the99% confidence level. Where there issignificant scatter in the data, twice theenrichment factor at the 95% confidencelevel is likely to govern. Thus, when theenrichment factor varies significantlyduring the 10 tests, not only is theenrichment factor based on the 95%confidence level, but an additionalmargin of safety is provided by doublingthe factor at the 95% confidence level forpurposes of determining the metal limitin collected PM.6 2

As for detection after the fact,sampling of collected dust is requiredevery eight hours to form a dailycomposite sample. The operator isallowed up to 48 hours to analyze thedaily composite 63 given that theanalytical procedures can take 24 to 48hours even for on-site laboratories. Inaddition, if the sample fails theconcentration limit for a metal, theoperator may analyze two duplicatesamples that he may have elected toobtain to determine if the failed sampleis an outlier. Analyses of these back-upsamples will also take up to 48 hours.Thus, it could take up to four days toconfirm that a dust sample has failed the

65 In addition, the methodology requires that a"safe enrichment factor" of 100 be used when ametal is at nondetect levels in the collected PM.Mercury, for example, may be at nondetect levelsbecause it is likely to be in the vapor form (and notcollected as PM) in an ESP or baghouse.

63 Except for "noncritical" metals where 30continuous days of analyses demonstrate that thedust concentration for the metal does not exceed10% of the concentration limit. For these metals,weekly composite samples must be analyzed. If aweekly composite exceeds 10% of the dustconcentration limit, however, daily analyses wouldbe again required.

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7178 Federal Register /Vol. '56, No. .35 / Thursday, February 21, .1991 / Rules and Regulations

concentration limit and that a violationof the metals emissions controls mayhave occurred. 64

Notwithstanding this provision of themethod, EPA expects that owners andoperators that want to comply with thespirit of the controls and to operate in amanner that is -protective of humanhealth and the environment will conducttriplicate analyses ofsamples for thosemetals that may exceed the"conservative" metal limit to avoid thetime delay of subsequently analyzingback-up samples if the initial samplefails the concentration limit. Owners/operators should-use historical data todetermine whether a metal may be closeto exceeding a concentration limit and,thus, routinely analyze "back-up"samples concurrently with the"required" sample for such metals.Further, EPA expects that enforcementofficials will consider whether theowner/operator.has taken suchprecautions to minimize the time duringwhich they may be operating underviolation conditions (if the dustconcentration actually exceeds the"violation" limit) in determiningappropriate enforcement action.

Notwithstanding these potentiallimitations, EPA believes that thismethodology is preferable to thematerial balance approach. Rather-thanattempt-to limit emissions by limitingmetal feed rates and extrapolatingthrough a number of not well-understood processes for furnaces -thatrecycle dust, the methodology in thefinal rule goes to the material that isclosest to to what is being emitted,collected PM, to extrapolate toemissions.

Limits on the operating parametersdiscussed above will be establishedunder this methodology during aminimum of three "compliance tests" ofthe first five of the ten emissions testsrequired to establish the enrichmentfactor for each metal. Consequently,

64 The methodology requires that two dust

concentration limits be established for each metal: a"conservative" limit and a "violation" limit. Forexample, the conservative limit is based on the safeenrichment factor of twice the enrichment factor atthe upper 95% confidetnce level, while the violationlimit is based on the enrichment factor at the upper95% confidence level. If the conservative limit isfailed more than 3 times out of 60 times, the owner/operator must notify the Director and he may burnhazardous waste for a total of 720 hours duringwhich: (1) The series of 10 emissions tests must beconducted to revise the enrichment factor and thedust concentration limits; and (2) the maximum feedrate of each metal in the hazardous waste isreduced by 50% (except during the three compliancetests). If the violation limit is exceeded, however,the operator is In violation of the metals controls(and he must also notify the Director, reduoe thefeed rate of metals in hazardous waste, and conductthe series of 10 tests to calculate.the revisedconcentration limits.)

during three of the ten runs, feed rates ofmetals in total hazardous waste -andpumpable hazardous waste will be atthe maximum level that the facility mayoperate during the remainder of interimstatus. Although the feed rate of metalsin the hazardous waste during the othertests need not be at the maximum levelestablished during the three"compliance tests", the feed rate mustbe at least 25% 65 of the compliance testlevel, and the facility must-operate atthe compliance test capacity (i.e., themaximum capacity at which the facilitymay operate during the remainder ofinterim status). The owner and operatormust demonstrate compliance with theapplicable PM standard and the metalsemissions standards of § 266.106(c) or(d) during all ten tests required toestablish enrichment factors. The rulerequires that the ten emissions tests todetermine enrichment factors beconducted in a two week period withnot more than two tests per day, andthat the three compliance tests (whenmetals feed rates from the hazardouswaste will be maximized to establishlimits for the remainder of interimstatus) be among the first five tests. EPAis providing these restrictions to ensurethat the enrichment factors arerepresentative of operations overseveral days when operating conditionscan vary, and to ensure that any effecton enrichment factors from the highmetals loading from spiked hazardouswaste during the three compliance testswill be detected during the subsequenttests.

The testing and operatingrequirements for this methodology areprescribed in detail in "AlternativeMethodology for Lnplementing MetalsControls" in the Methods Manual.

b. Daily Emissions Testing. Under thisoption, the owner or operator mustconduct daily emissions testing toconfirm that the metals emission limitsare not exceeded. Sampling must beconducted for a minimum of 6 hourseach day when hazardous waste isburned. To ensure that sampledemissions are representative of normalemissions that day, the testing must beconducted when burning normalhazardous waste for that.day (i.e.,considering metals content, point of

"5 We are not requiring the facility operate at themaximum (i.e.. compliance test) metals feed ratefrom hazardous waste (or other feedstreams) duringall ten emissions tests because the purpose of theremaining tests is to obtain data to statisticallydetermine the enrichment factor. Thus, it isimportant to determine how the enrichment factormay change as the feed rate of metals from variousfeedstreams varies. Nonetheless, the metal feedratein the hazardous waste must bee mininm of'25% ofcompliance test limits during the remaining 7enrichment factor determinations tests.

induction into the system, and physicalform.of the waste) at normal feed -ratesfor that day andwhen the air pollutioncontrol system is operated under normalconditions. See'§ 266.103(c)(3)(ii)(B).

Given that acitual, emissions samplingis used under this option to determinecompliance with emission standards,those operating conditions that apply toother BIFs after certification ofcompliance that are designed to controlmetals -emissions are not necessary. See§ 266.103(c)(1). The operatingparameters that need not be limited atcertification of compliance under thismethod are:*• MaximumfeedTate of-each metal in

total feedstreams, total hazardous wastefeedstreams, or pumpable hazardouswaste feedstreams;

e Maximum feed rate of purnpablehazardous waste;

* Maximum feed rate of chlorine intotal feedstreams;

e Maximum, combustion chambertemperature and temperature at the inletto the air pollution control -system(APCS); and

e Key parameters to ensure properoperation of the APCS.

This approach has one drawback-there is a time delay before a violationof the emissions limits is determinedgiven that it normally takes a week ormore to obtain the results of the stacksampling. To minimize the impact of thisproblem, the operator is required toknow the metals concentration and feedrate -of hazardous waste at all times andmust determine if a change in metal feedrate from the hazardous waste is likelyto result in exceedance of a metalemission limit.

c. Conditioning Prior to ComplianceTesting. Under this approach (see§ 266.103(c)(3)(ii)(C)), the operator mustcondition the furnace to ensure thatmetals emissions are in equilibrium withmetals fed into the system from allfeedstreams. The owner or operatormust determine using engineeringjudgment when the system has reachedequilibrium (i.e., how long the systemmust be conditioned). Duringconditioning, hazardous waste and rawmaterials having the same metalscontent as will be fed during thecompliance test must be fed at feedrates that will be-fed during thecompliance test.

Under this method, limits for alloperating parameters under§ 266.103(c)(1) must be establishedduring the compliance test.

•5. Trial Burns

A-trial burn, or data in lieu of the trialburn'(e.g.,emissions datafrominterim




status compliance testing) is required todemonstrate the performancecapabilities of a system and to establishthe operating limits of a facility for theduration of the operating permit.Compliance limits will be based on theoperating conditions and emission ratesobserved during the trial burn.Therefore, to obtain the most flexiblecompliance limits, an owner/operatorshould conduct test burns and the trialburn under worst-case conditions (thosethat maximize emissions withoutexceeding the established limits). Theseconditions include feeding the wasteused in the trial burn at a feed rate andmetals concentration that reflect thehighest levels expected in present orfuture operations.

Spiking with Metals. To achieve themaximum allowable concentration ofmetals, the owner/operator may wish tospike the waste to artificially highconcentrations of the metals during thepre-trial burn period and during the trialburn. However, the owner/operator maynot feed metals at levels higher thanthose documented in the part B permitapplication as those not likely to resultin emissions exceeding allowable levels.Permit officials will consider thisdocumentation in establishing pre-trialburn permit conditions for new permits.

6. Monitoring and AnalysisRequirements

a. Emissions Testing. Emissionstesting and analysis for metals must beconducted using "Methodology for theDetermination of Metal Emissions inExhaust Gases from Hazardous WasteIncineration and Similar CombustionProcesses" provided in Methods Manualfor Compliance with the BIFRegulations 66, incorporated in today'srule as appendix IX of part 266. Themethodology describes the use of amultiple metals sampling train. Themethodology also describes andprovides references to the appropriateanalytical techniques in Test Methodsfor Evaluation Solid Wastes (SW-846),incorporated by reference in § 260.11,that must be used to analyze samples.

b. Analysis of Feedstreams.Feedstreams must be analyzed for eachof the 10 regulated metals that couldreasonably be expected to be in thehazardous waste. If a particular metal isexcluded from the analysis, the basis forexclusion must be documented andincluded in the operating record.Methods for sampling and analysis offeedstreams for metals are prescribed inSW-846.

11 U.S. EPA. Methods Manual for Compliancewith the BlF Regulations, December 1990, EPA/530-SW-91-lO0. NTIS publication number PB91-120-006.

D. Interim Status ComplianceRequirements

As prescribed in $266.103, anddiscussed in section VII of part three ofthis preamble, boilers and industrialfurnaces operating under interim statusmust comply with the metals emissionsstandards during interim status.

V. Controls for Emissions of HydrogenChloride and Chlorine Gas

Today's final rule uses a three-tieredregulatory approach to limit HCl and C2emissions (see 1 266.107), an approachidentical to that used to controlnoncarcinogenic toxic metals emissions.

A. Background Information

In the 1987 proposed rule, EPA statedits intention to develop risk-based HCIemission standards in the same formatand for the same reasons as theproposed metals emission limits. TheHC1 emission limits for a particulardevice would have been based on thedevice type and capacity, and on thetype of surrounding terrain. In the 1989supplemental notice, EPA discussed analternative approach to make thestandards a function of stack height,terrain, and land use rather than afunction of device type and capacity.The reasons for the change were thesame as those described above in thediscussion of the metals standards.

Controls on CI were proposed onApril 27, 1990 (55 FR 17866) because Cl2can be emitted from devices burningchlorinated wastes if insufficienthydrogen is available (i.e., from otherhydrocarbon compounds or watervapor) to react with all of the chlorinepresent in the waste. In recent tests 67 ofa cement kiln, EPA found thatapproximately 50% of gaseous chlorineemissions were in the form of C12 (andthe other 50% was in the form of HC1). Inthe April 1990 proposal, the Agencyproposed a Cl6 RAC of 0.4 pg/m 3.

In the 1989 supplemental notice, EPAalso discussed the possibility of usingcontinuous HCI monitors in lieu of thewaste feed analysis approach formonitoring HCI emissions are likely tobe close to allowable emissions. TheAgency continues to believe that this isa reasonable approach and believes thatit can be effectively implemented duringthe permit process as necessary usingthe omnibus authority.6 8

67 U.S. EPA, Emission Testing of a PrecalcinerCement Kiln at Louisville, Nebraska, November1990. Document No. EPA/530-SW-91-015.

68 EPA notes that permit writers choosing toinvoke the omnibus permit authority of5 270.32(b)(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for the

B. Response to Comments

The Agency received a number ofcomments on the proposed HCl and C12controls as discussed below.

1. Short Term HCl RAC

A number of commenters stated thatthe Agency's support for the proposed 3-minute RAC for HCl was inadequate.The Agency is currently developing anew methodology for evaluating healtheffects data to develop a no-adverse-effect short-term exposure level.6 9

Given that the new methodology has notbeen approved by the Agency, today'sfinal rule does not establish a short-termRAC for HCL.

We note that the Tier I chlorine feedrate limits proposed in the 1989supplemental notice were based on theshort-term HCl RAC because the short-term exposure RAC provided morerestrictive feed rate limits than the long-term RAC. Consequently, the 1989proposed chlorine feed rate limits arenot included in today's final rule. Inestablishing the Tier I feed rate limitsfor chlorine in today's final rule, theAgency considered both the long-termHCI RAC (i.e., 7 jig/m 3) and the CL2RAC (i.e., 0.4 pg/m 3], and thepartitioning between the two pollutantsin stack gases. Given that the Agencyhas tested for C12 emissions at only twofacilities, and at one of the facilitiesmore than 50% of the chlorinepartitioned to C12, the Agencyconservatively assumed in calculatingfeed rate limits that 100% of the chlorinewould be partitioned to CI. Because theC12 RAC is more than an order ofmagnitude lower than the HCl RAC, theTier I chlorine limits were based on100% conversion of chlorine to C12. Ifapplicants believe that this assumptionis too conservative, they may conductemissions testing to document C 2 andHCl emission rates.

2. Need for C12 Controls

Many commenters stated that C 2

controls are unnecessary. Onecommenter believed that very littlehydrogen is needed to react with C12 toform HCL. Another commenter believedthat operating conditions for boilers andindustrial furnaces are not conducive tothe formation of C6i. Another commenterstated that the proposed limits to control

conditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibusauthority.

9 Memorandum dated September 1 from SusanGriffin. EPA, to Bob Holloway, EPA, entitled"Derivation of Short-Term RAC for HCI"

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HCl emissions will provide adequatecontrol of C2 emissions as well.

The Agency does not agree with thesecommenters. As discussed above,emissions testing indicates that asubstantial fraction of gaseous chlorinecan be emitted in the form of C12. Inaddition, the HCI controls may not beadequate to control C12 emissions.Because C12 has a much lower solubilityin water than does HC1, the use of wetscrubbers as the principle emissionscontrol device for HCI is not likely tosignificantly reduce emissions of C12. C12emissions can be controlled, however,by increasing the hydrogen content offeedstreams (e.g., by adding steam] orby decreasing the feed rate of chlorine.Moreover, EPA does not believe thathigh C12 emissions relative to HClemissions is a widespread occurence.

3. HCI Emission Test Procedures

A number of commenters who own oroperate cement kilns expressed concernthat EPA's HCI stack sampling andanalysis procedure (see section 3.3 inMethods Manual for Compliance withthe BIF Regulations] was inappropriatebecause it counted as HCI chlorine ininorganic chloride salts and chlorideions that are emitted as ammoniumchloride. The Agency has determined 70that the filter in the sample probe, infact, effectively removes fine particulatechloride salts so that they do notinterfere with the HCI determination.The Agency agrees, however, withcommenters that the procedure mayconsider as HCI chloride ions that areemitted as ammonium chloride.7

Although the Agency has not developeda sampling and analysis procedure thatwould correct this problem, we do notbelieve that any such over-reporting ofHCI will cause a cement kiln to exceedthe HCI standard. This is because thehighly alkaline particulate matterresulting from the limestone rawmaterials effectively neutralizes much ofthe chlorine generated from hazardouswaste fed into the kiln.

4. Technology-Based HCl controls

Several commenters stated thattechnology-based HCI emission controlsapplicable to hazardous wasteincinerators (i.e., 99% reduction ofemissions in the stack gas) should alsoapply to BIFs. As discussed in theproposed rule, the Agency continues tobelieve that a 99% reduction standard

7O U.S. EPA, Emission Testing of a Precalciner

Cement Kiln at Louisville. Nebraska, November1990. Document No. EPA/530-SW-91-016.

I I U.S. EPA, Emissions Testing of a Wet CementKiln at Hannibal, MO, December 1990. DocumentNo. EPA/530-SW-91-017.

for BIFs to control HC1 emissions maybe neither technically feasible nornecessary to protect human health andthe environment. The Agency believesthat the process chemistry of someindustrial furnaces (e.g., cement kilns)generally results in low HCI emissionsand concerns about tube corrosiongenerally limit HCI concentrations inboiler emissions. Given the lowuncontrolled HCI concentrations inmany BIFs, a 99% reduction standard inaddition to the health-based standardrequired by today's final rule, may notbe cost-effective. Commenters did notprovide data or information that wouldsupport the need for, and the cost-effectiveness of a technology-basedstandard in addition to the health-basedstandard provided by the final rule.

We note that the Agency is currentlydeveloping health effects data for twoother acid gases: hydrogen fluoride andhydrogen bromide.

C. Implementation

Procedures for implementing the HCIand C12 controls are virtually identical tothose for the metals controls discussedabove.

1. Emissions Testing

Collection and analysis of HCI andCl2 in stack gas emission samples mustbe conducted according to theprocedures prescribed in section 3.3 ofthe Methods Manual for Compliancewith the BIF Regulations, (MethodsManual) incorporated in today's rule asappendix IX of part 266. The MethodsManual describes two procedures forsampling emissions for HCI and Cl2 :Methods 0050 and 0051. Method 0050collects a sample isokinetically and is,therefore, particularly suited forsampling at sources emitting acidparticulate matter (e.g., HCI dissolved inwater droplets], such as those controlledby wet scrubbers. Method 0051 uses amidget impinger train sampling methoddesigned for sampling sources of HCIand C12 emissions not in particulateform. Samples collected using eithermethod must be analyzed using Method9057 which is also described in theMethods Manual.

2. Wastes Analysis

Methods for sampling and analysis offeedstreams for total chlorine andchloride are described in detail in SW-846.

3. Interim Status ComplianceRequirements.

As discussed in section VII of partthree of this preamble, boilers andindustrial furnaces operating underinterim status must comply with the HCI

and Cl2 emissions standards duringinterim status.

VI. Nontechnical Requirements

As proposed, the final rule requiresBIFs to comply with the nontechnicalstandards applicable to other hazardouswaste treatment, storage, and disposalfacilities. These nontechnical standardsaddress the potential hazards fromspills, fires, explosions, and unintendedegress; require compliance with themanifest system to complete the cradleto grave tracking system; ensure thathazardous wastes (and hazardousresidues] are removed from the siteupon closure; and ensure that theowners and operators are financiallycapable of complying with thestandards. BIFs burning hazardouswaste fuels that operate storagefacilities must already comply withthese standards under existing§ 266.35(c).

We also note, in particular, thatowners and operators of BIFs aresubject to the waste analysisrequirements of § § 264.13 and 265.13 byreference. See §§ 266.102(a)(2)(ii) forpermitted facilities and 266.103(a)(4)(ii)for interim status facilities. Before awaste is stored or burned, the owner oroperator must obtain a detailedchemical and physical analysis of arepresentative sample of the wastesufficient to enable the owner oroperator to comply with today's rule.

The nontechnical standards providedin today's rule are identical to those thatcurrently apply to hazardous wasteincinerators. In today's rule,§ 266.102(a)(2) applies these standardsto permitted BIFs and § 266.103(a)(4)applies these standards to BIFsoperating in interim status.

Finally, we note that, as proposed,today's rule applies the same controlson fugitive emissions that currentlyapply to hazardous waste incinerators.The controls apply to facilities operatingunder a permit (see § 266.102(e)(7)(i)and, on the effective date of the rule, tofacilities operating under interim status(see § 266.103(h)). The controls providefor alternative control strategiesincluding: (1) Keeping the combustionzone where hazardous waste is burned(or where emissions from such burningmay migrate) totally sealed; and (2)maintaining the combustioi, zonepressure lower than atmosphericpressure.

VII. Interim Status Standards

In addition to the nontechnicalstandards discussed above, today's finalrule requires facilities with interimstatus to comply with substantive



Federal Register / Vol 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

emission controls for metals, HCl, C6particulates, and CO (and, whereapplicable, HC and dioxins and furans].Owners and operators must certifycompliance with the emissions controlsunder a prescribed schedule, establishlimits on prescribed operatingparameters, and operate within thoselimits throughout interim status.

Given that interim status requirementsare self-implementing, the Agency hasdeveloped comprehensive interim statusrequirements to ensure that thestandards are implemented effectively.To assist the regulated community incomplying with the requirements, EPA isdeveloping a guidance documententitled Interim Status GuidanceDocument for BIF (ISGD). The guidancedocument will be available shortly afterpublication of the final rule in theFederal Register. The ISGD willsummarize the provisions of the rule,provide example forms that may be usedto submit data and information requiredby the certifications of precomplianceand compliance (see discussions below),and provide guidance on developing acompliance test protocol. To providefurther assistance to the regulatedcommunity, EPA plans to conduct aseries of workshops open to the publicto explain how the interim statusstandards work. The workshops arescheduled to begin shortly afterpublication of the final rule in theFederal Register. To obtain a copy of theISGD or information on the dates andlocations of the workshop, contact thesources identified at the beginning ofthis preamble under "FOR FURTHERINFORMATION CONTACT".

The following sections summarizehow the interim status standards work.A. Certification Schedule

1. Certification of PrecomplianceThe BIF rule is effective 6 months

after the date of promulgation. By theeffective date, an owner/operator mustsubmit a certification of precomplianceproviding prescribed informationsupporting a determination thatemissions of individual metals, HCI, Cl2,and particulates are rot likely to exceedallowable levels. See § 266.103(b)(2). Forcertification of precompliance, theowner/operator must use engineeringjudgment to evaluate availableinformation and data (or must use EPA-prescribed default data provided insections 8.0 and 9.0 of Methods Manualfor Compliance with the BIFRegulations, incorporated in today's ruleas Appendix IX of part 266) to determinethat, under the operating limits (for EPA-prescribed parameters) that the owner/operator establishes, emissions are not

likely to exceed the allowable emissionsprovided by § § 260.105, 266.100, and266.107. The owner and operator mustthen comply with these operatingconditions (see discussion in sectionVII.B below) submitted in theprecompliance certification during theinterim status period of operation until arevised precompliance certification issubmitted or until a certification ofcompliance is submitted as discussedbelow.

In addition, by the effective date ofthe rule, the owner or operator mustsubmit a notice for publication in amajor local newspaper of generalcirculation providing the general facilityinformation prescribed by§ 266.103(b)(6). The information thatmust be provided in the notice includes:The name and address of the owner andoperator of the facility; the type offacility, the type and quantity ofhazardous waste burned; the locationwhere the operation record of thefacility can be viewed; a notificationthat a facility mailing list is beingestablished so that interested partiesmay notify the Agency that they wish tobe placed on the mailing list to receivefuture information and notices about thefacility; a brief summary of the RCRAregulatory system for BIFs; and theaddress of the EPA Regional Officewhere additional information on theRCRA regulatory system may beobtained. EPA is requiring this publicnotice to ensure that the local citizenryis aware that the BIF is burninghazardous waste and that, to the extentdesired, the local citizenry may becomebetter informed about the facilityoperations through site inspections andreview cf data in the operating record.In turn, this opportunity for localinvolvement in facility operationsshould provide an added incentive forthe owner and operator to comply withthe spirit and letter of the interim statusstandards.

EPA notes that facilities that meet thedefinition of "in existence" of§ 266.103(a(l)(ii) but that are notburning hazardous waste on theeffective date of the rule mustnonetheless submit a certification ofprecompliance based on plannedoperations. The certification may berevised at any time in the future ifnecessary. See § 266.103(b)(8).

2. Certification of Ccmpliance

Within 18 months of promulgation, theowner/operator must conductcompliance testing 72 and subrrdt a

1

72 We note that compliance testing may beconducted only under operating conditions forwhich the facility has submitted a certification of

certification of compliance with thestandards for individual metals(§ 266.106), HCI and C6 (1 266.107),particulates (§ 266.105), and CO, and,where applicable, HC and dioxins/furans (§ 266.104 (b) through (e)). Thecertification of compliance is based onemissions testing and establishesoperating limits for EPA-prescribedparameters based on the compliancetest. See § 266.103(c)(1).

If the owner/operator cannot submitthe certification of compliance within 18months of promulgation however, hemust either: (1) Notify the Director thathe is taking an automatic 12-monthextension under which hazardous wasteburning is limited to a total of 720 hours;(2) obtain a case-by-case extension oftime for reasons beyond his control; or(3) stop burning hazardous waste andbegin closure of the hazardous wasteportion of the facility. See§ 266.103(c)(7).

The case-by-case time extension willbe provided by the Director if hedetermines that the owner or operatorhas made a good faith effort to complywith the requirements in a timelymanner but, for reasons beyond his/hercontrol, are not able to meet thecertification of compliance deadline.Reasons could include inability tocomplete modifications to an airpollution control system in time toconduct the compliance test to supportthe certification, or a major, unplannedoutage of the facility (e.g., need toreplace refractory in a kiln) just prior toscheduled compliance testing, or asdiscussed earlier, HC levels attributableto organics in raw materials. TheDirector may use his discretion todetermine the length of the extension.73

The Director also may imposeconditions that ensure that the boiler orindustrial furnace will be operated in amanner that protects human health andthe envirorment, provided that theDirector documents the basis for addingsuch a condition and provides theapplicant opportunity to comment on it.

precompliance. This is because the facility may onlyoperate after the effective date of the rule and priorto submittal of a certification of compliance underconditions for which it has car'ified precompliance.If any applicable emission standard is exceededduring the coinpliance test [or during pretesting), !hefacility must ir-nediately submit a revisedcertification of precompliance establishing revised(i.e., more stringent) operating limits.

73 We would not expect for the Director normallyto limit the hours that hazardous waste may beburned under a case-by-case extension given thatthe owner/ope rator must support the need for theextension and, if granted, the extension must be fora legitimate need. In contrast, the hours of burningare limited for the automatic 12-month extensionbecause there is no judgement by the Director that,in fact, the extension is warranted.

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In addition, we note that a case-by-case extension may be requested andgranted for any interim statuscertification deadline under § 266.103 (c)or (d). A case-by-case extension may begranted after an owner/operator haselected to take the 12-month automaticextension, an extension may be grantedif the owner/operator cannot complywith the recertification schedule (seediscussion belowj and an existingextension may be extended.3. Recertification

Owners and operators mustperiodically conduct compliance testingand recertify compliance with thestandards for individual metals, HCI and-Cl2 particulates, and CO, and, whereapplicable, HC and dioxins/furanswithin three years of the previouscertification while they remain ininterim status [i.e., until an operatingpermit is issued under § 270.66). See§ 266.103(d). EPA is requiringrecertifications primarily to ensure thatair pollution control systems do notdeteriorate over time.

4. Failure to Comply with theCertification Schedule

If the owner or operator does notcomply with the certification schedule,all hazardous waste burning must ceaseas of the date of the missed deadline,and closure must commence. See§ 266.103(e). Any burning of hazardouswaste by such a device after failure tocomply with the certification schedulemust be under a RCRA operating permit.See § 270.66.

To comply with the certificationschedule, complete and accuratecertifications of precompliance andcompliance must be submitted by theapplicable deadlines. (Although thedeadline for certification of compliancemay be extended (see § 266.103(c)(7)),the deadline for certification ofprecompliance may not be extended.) Inaddition to terminating interim status ifthe owner and operator do not complywith the certification schedule, EPA willalso take appropriate enforcementaction.

When closing a BIF, all hazardouswaste and hazardous waste residues,including, but not limited to, ash,scrubber water, and scrubber sludges,must be removed from the affected BIF.In addition, the owner/operator mustcomply with the general interim statusclosure requirements of § § 265.111-265.115, as amended. Theserequirements, which are incorporated byreference into today's rule, specifyclosure performance standards;submission of and compliance with awritten closure plan; disposal or

decontamination of equipment,structures, and soils; and certificationprocedures for closure.

We note that under amended§ 265.112(d)(2), for an owner or operatorwho fails to submit a completecertification of compliance by theapplicable compliance deadline(including the automatic 12-monthextension or the case-by-case extensionunder § 266.103(c)(7)(i), the date that he'expects to begin closure" is within 30days after the applicable deadline.Therefore, for example, for an ownerwho takes the automatic 12-monthextension, the closure notificationrequirements of § 265.112(d)(1) or theclosure activity requirements of§ 265.113 would not be triggered unlessand until the owner fails to submit acomplete certification of compliance bythe 12-month extended deadlihe and acase-by-case extension beyond the 12-month extension was not obtained.

For any other BIF owner or operatorclosing during interim status operation(i.e., one who closes between theeffective date of the rule but before theinterim status compliance deadline of 18months after promulgation of the rule, orone who submits a completecertification of compliance by theapplicable 18-month compliancedeadline, the 12-month automaticextension, or case-by-case extension,and closes during interim status), thedate when he "expects to begin closure"under § 265.112(d)(2) will remain hitherwithin 30 days after the date on whichany hazardous waste management unitreceives the known final volume ofhazardous waste, or if there is areasonable possibility that the unit willreceive additional hazardous waste, nolater than one year after the date onwhich the unit received the most recentvolume of hazardous waste.

5. Development of the CertificationSchedule

In the 1989 supplemental notice, theAgency requested comment onalternative schedules for requiringcompliance with the emissionsstandards during interim status. TheAgency selected a certification deadlineof 18 months (with provision forextensions) because we believe thatmost facilities will be able to install thenecessary monitoring equipment,conduct any precompliance testing thatmay be necessary, and conductcompliance testing within that timeperiod. Although 18 months from thedate of promulgation is a fairly shortperiod of time, we note that Agencystaff have made numerous publicpresentations and have had numerous

discussions 74 with the regulatedcommunity, including, in particular, thedevelopment of interim statuscompliance procedures. Thus, facilityowners/operators have had someadvance indication of the generalregulatory approach taken in the finalrule.

The Agency received a comment thatthe air emission standards for cementkilns should be instituted more quicklythan the schedule proposed. Thecommenter believed that acceleratingthe schedule will not place an excessiveburden on these facilities because theregulations were proposed far enough inadvance for cement kilns to come intocompliance. The Agency has consideredthis comment and: (1) Sees nocompelling reason to single out cementkilns from other BIFs for an acceleratedschedule; and (2) continues to believethat an 18-month compliance period isrepresentative of the time required toimplement necessary plant design orprocess modifications, install monitoringand compliance equipment, conductfacility compliance testing, and submit acertification of compliance testing thatdocuments key operating limits duringthe remainder of the interim statusperiod. In fact, the Agency is concernedthat in some situations, where, forexample, the air pollution controlsystem may need to be modified, an 18-month deadline may not provide enoughtime to complete modifications, "shake-down" the system, conduct pre-testing 75, conduct compliance testing,and analyze test data and submit acertification of compliance. Thus, thefinal rule includes provisions for timeextensions to all certification deadlinesexcept for certification of precomplianceunder § 266.103(b).B. Limits on Operating Parameters

Limits on operating parameters duringinterim status are established atcertification of precompliance and atcertification of compliance followingemissions testing 18 months (unlessextended) after promulgation of the rule.The operating conditions can be revisedprior to certification of compliance bysubmitting a revised certification ofprecompliance. The operating conditionscan be revised after certification of

74 See the public docket for this rulemaking forsummaries of meetings held with groups including:Cement Kiln Recycling Coalition, ChemicalManufacturers Association, National Solid WasteManagement Association, Council of IndustrialBoiler Operators, and Hazardous Waste treatmentCouncil.

75 Although pretesting is not required, EPAbelieves that most facilities will conduct pretestingbefore conducting the formal compliance testingwith all its attendant QA/QC requirements.



Fe~dAral ReQister / Vnl. 56. No. 35 I Thursday, February 21, 1991 / Rules and Regulations 78

compliance by conducting emissionstesting and submitting a revisedcertification of compliance.

After the effective date of the rule andprior to certification of compliance withthe emissions standards based onemissions testing, a facility may operateonly under those conditions for whichthe facility has submitted a"precompliance" certificationdemonstrating that emissions ofindividual metals, HCI, C12, andparticulates are not likely to exceedallowable levels. The operatingconditions for which limits areestablished by precompliance are (see§ 266.103(b)(3)):

- Feed rate of each of the 10 metalsin:-Total feed streams, except for

furnaces that recycle collectedparticulate matter (see discussion insection VI.LI below)

-Total hazardous waste feed streams-Total pumpable hazardous waste feed

streams;- Total feed rate of chlorine and

chloride in all feed streams;- Total feed rate of ash in all feed

streams, except for cement and light-weight aggregate facilities for which ashcontent of feed streams is not anoperating parameter;

- Total feed rate of hazardous wasteand feed rate of pumpable hazardouswaste; and

e Maximum capacity in appropriateunits such as heat input, steamproduction, or raw material feed rate.

In addition, the following parametersmust be considered in demonstratingprecompliance and must becontinuously monitored (and recordsmaintained in the operating log) whenmonitoring systems are installed (see§ 266.103(b)(6)):

9 Maximum combustion zonetemperature;

* Maximum flue gas temperatureentering the PM APCS; and

- Limits for APCS-specific operatingparameters.

Once a facility has conductedcompliance testing and certifiedcompliance with the emissionsstandards, limits for all of the aboveparameters, as well as for CO (and,where applicable, HC) are establishedbased on the compliance test andremain in force until recertificationunder new conditions. See§ 266.103(c)(1).

C. Automatic Waste Feed Cutoff

Upon certification of compliance, anautomatic hazardous waste feed cutoffsystem must engage when the limits(established in the certification) for the

following operating parameters areexceeded (see § 266.103(g)):

- Total feed rate of hazardous wasteand feed rate of pumpable hazardouswaste;

a Limits on CO and, whereapplicable, HG;

* Maximum production rate inappropriate units such as heat input,steam production, or raw material feedrate;

* Maximum combustion zonetemperature;

9 Maximum flue gas temperatureentering the PM APCS; and

• Limits for APCS-specific operatingparameters.

Facilities operating during interimstatus after certification of compliancemust test the automatic waste feedshutoff system once every 7 days toensure that it is operating properly,unless an owner/operator can documentthat weekly testing will result in unsafeconditions. See § 266.103(j)(3). In allcases, testing at least every 30 days isrequired. Owners/operators arerequired to document the results ofthese tests and all automatic waste feedshutoffs that occur during normaloperations.

D. Sham Recycling Policy

The BIF rules supersede the Agency'ssham recycling policy (see 48 FR 11157(March 16, 1983)) after the owner oroperator certifies during interim statuscompliance with the emissionsstandards for metals, HCI, C12,particulates, and CO (and, whereapplicable, HC and dioxins and furans).Thus, after certification of compliance, aBIF may burn hazardous waste (otherthan waste fed solely as an ingredient orsolely for material recovery) with aheating value lower than the 5,000 Btu/lb limit generally considered heretoforeto be the minimum for a legitimatehazardous waste fuel. Although theAgency considers such burning to betreatment, we believe that conformancewith the emissions standards uponcertification of compliance under§ 266.103(c) will ensure protection ofhuman health and the environment.(Prior to today's rule, BIFs burning ahazardous waste that was notconsidered to be a legitimate fuel weresubject to the subpart 0 incineratorstandards of parts 264 and 265,assuming burning was not for someother legitimate recycling purpose, suchas material recovery.)

Although we indicated above that aBIF may burn hazardous waste for thepurpose of treatment upon certificationof compliance, today's rule allows BIFsto burn such hazardous waste for a totalperiod of time not to exceed 720 hours

prior to certification of compliance. See§ 266.103(a)(6). The rule allows suchburning only for purposes of compliancetesting (and pretesting to prepare forcompliance testing) to determine thatthe device can comply with theemissions standards while burningwaste for treatment. The rule limits suchburning to a total of 720 hours becausewe believe that period of time isadequate to complete any pretesting andcompliance testing, and it is the sameperiod of time that new BIFs may burnhazardous waste during the pretrialburn period under § 270.66(b)(1).

The Agency discussed three options inthe 1989 supplemental notice forsuperseding the sham recycling policy:Rescinding the sham recycling policy onthe effective date of the final rule;rescinding the sham recycling policywhen a facility comes into compliancewith the interim status emissionstandards; or leaving the sham recyclingpolicy in effect until a RCRA operatingpermit is issued.

The Agency received commentssupporting all three of the options. Eightcommenters supported the first option,rescinding the sham recycling policy onthe effective date of the final rule,because the policy is consideredguidance. Eight commenters supportedthe second option, rescinding the shampolicy when facilities come intocompliance with the interim statusemission standards, because thestandards are protective of humanhealth and the environment. Fivecommenters supported the third option,leaving the sham recycling policy ineffect until a facility is issued a RCRAoperating permit, because the permitwriter oversight during the permitprocess is necessary to ensure that afacility complies with the appropriateregulations.

The Agency believes that theprocedures required for certification ofthe interim status emissions standardsare adequate to ensure effectiveimplementation and enforcement of thestandards. The only emissions standardapplicable to permitted facilities that isnot required during interim status is thedestruction and removal efficiency(DRE) standard requiring a trial burn todemonstrate 99.99% DRE. The Agencydoes not believe that this is necessarybecause emissions testing of boilers andindustrial furnaces indicates thatfacilities with CO and HC levels withinthe limits established by today's rulealso are likely to achieve 99.99% DRE.

It should be noted that in rescindingthe sham recycling policy for these typesof regulated boilers and industrialfurnaces, the Agency is not altering in

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7184 Federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 l' Rules and Regulations

any way what secondary materials aredefined as solid and hazardous wasteswhen burned for legitimate energyrecovery. Thus, all spent materials,sludges, and by-products are solidwastes when burned for recovery, as areoff-specification commerical chemicalproducts which are burned as fuels (orused as a component of fuels) in lieu oftheir original intended use. See§ § 261.2(c)(2) and 261.33. (Non-listedhazardous commercial chemicalproducts (i.e., those that exhibit acharacteristic but are not listed in§ 261.33) are likewise solid wastes whenthey are recycled in ways that differfrom their normal use. 50 FR at 14219(April 11, 1985).) With respect to theissue of what constitutes a normalmanner of use for an off-specificationcommercial chemical product that hassome Btu value, or the issue of whensuch a material is used "in lieu of [its]original intended use" (§ 261.33) and sois a solid and hazardous waste, theAgency notes that not every type ofburning ostensibly for energy recoveryis considered to qualify. Inappropriatemodes of burning thus do not rendersuch materials non-wastes. For example,if ignitable off-specification natural gascondensate is burtned as a motor fuel, orreactive jet fuel (U 133, hydrazine) isburned as conventional fuel oil, suchmaterials are solid and hazardouswastes and subject to subtitle Ccontrols. This is because the mode ofburning is not at all like these materials'original intended use.E. Submittal of Part B Applications

Permit writers will require owners andoperators to submit part B applicationsfor operating permits on a scheduleconsidering the relative hazard tohuman health and environment thefacility poses compared to other storage,treatment, and disposal facilities withinthe Director's purview.

F. DRE TestingAs proposed, testing to demonstrate

99.99% destruction and removalefficiency (DRE) 0f organic compoundsin the waste is not required underinterim status. The complexity and costsof DRE testing, as well as thesubstantial interaction needed betweenowners/operators and regulatoryofficials, make such testingimpracticable during interim status. EPAexpects that the control requirements forCO and HC will result in low levels ofemissions of organic compounds.

G. Chlorinated Dioxins and FuransAs proposed, hazardous waste

containing or derived from any of thefollowing dioxin-listed wastes cannot be

burned in a boiler or industrial furnaceoperating under interim status: EPAHazardous Waste Nos. F020, F021, F022,F023, F026, and F027. Burning thesedioxin-containing wastes'during interimstatus is prohibited because boilers andindustrial furnaces cannot be assumedto achieve the 99.9999 percent DRErequired for these wastes.

Even though these wastes may not beburned during interim status,chlorinated dioxins and furans may beemitted as PICs under certain conditions(i.e., when the PM control device isoperated within the temperature rangeof 450-750°F, or when HCconcentrations exceed 20 ppmv) asdiscussed in section ULE of part three ofthe preamble. EPA believes that theemissions testing and risk assessmentrequirements of § 266.104(e) can beeffectively implemented during interimstatus without significant EPAinteraction. Thus, the rule requires theowner or operator to certify compliancewith those requirements, as applicable.

H. Special Requirements for Furnaces

Today's rule provides special interimstatus requirements for industrialfurnances that feed hazardous waste,except hazardous waste fed solely as aningredient" at locations other than the"hot" end where the product isdischarged and fuels are normally firedto ensure adequate combustion ofhazardous waste prior to conducting atrial burn during the part B permitprocess (see § 266.103(a)(5)) as follows:(1) The combustion gases must have aminimum temperature of 1800 °F at thepoint where the waste is introduced; 77

76 Hazardous waste is burned solely as aningredient If it is burned for neither energy recovery(i.e., it has a heating value less than 5,000 Btu/]b}nor treatment or destruction (i.e., it contains a totalof less than 500 ppm toxic nonmetal constituentslisted in appendix VIII. part 261).

" EPA is aware that cement companies haveexperimented with feeding containerized waste intothe upper, raw material feed end of the kiln usingfeed chutes that propel the containers down into thekiln before they rupture and expose the waste to thecombustion gas [and begin to releasehydrocarbons. In such a situation, the temperaturelimit applies at the point that the waste may beginto release hydrocarbons--the point where thecontainer Impacts the charge bed. The temperaturelimit does not apply to the point where thecontainer is actually charged into the kiln. (If,however, a noncontainerized waste is fired into thekiln at the upper end, the 11M0 F temperature limitapplies at the location where the waste exits thefiring system.) Although this discussion pertains tocement kilns, EPA notes that the subjectrequirements apply to any industrial furnance thatfeeds hazardous waste at a location other than the"hot" end as described in the text.

(2) the owner or operator mustdetermine (and include suchdetermination in the operating record)that there is sufficient oxygen present tocombust the waste; (3) the continuoushydrocarbon monitoring controls .provided by § 266.104(d) apply; and (4)for cement kilns, hazardous waste mustbe fed into the kiln itself;

EPA established a minimumtemperature of 1800 F for the location ofhazardous waste firing and is requiringthat the owner/operator demonstratethat adequate oxygen is present tosustain combustion given that it isgenerally accepted that organiccompounds are readily destroyed attemperatures above 1800 *F in thepresence of adequate oxygen. Thedemonstration of adequate oxygen isparticularly important for cement kilnsbecause they are operated close tostoichiometric oxygen levels (i.e., withlittle excess oxygen in the kiln) toefficiently maintain the hightemperatures necessary to calcine andsinter the raw materials. Althoughhigher excess oxygen levels wouldbetter ensure more complete combustionof fuels, operating at higher oxygenlevels is less thermally efficient andreduces the kiln production capacity.

In addition, continuous hydrocarbon(HC) monitoring is required todemonstrate that HC levels do notexceed the regulatory limit of 20 ppmvon a hourly rolling average basis (oralternative level established under§ 266.104(fo) irrespective of whether theCO level is less than 100 ppmv whereHC monitoring is not normally required.See § 266.103(a)(5). EPA is requiring HCmonitoring because of the concern thatCO monitoring alone may not be anadequate indicator of good combustionconditions when hazardous waste is fedat locations other than where(nonhazardous) fuels are normally fired.See discussion in part three, sectionII.B.4.a of this preamble. Continuousmonitoring of HC and compliance withthe applicable operating limit is requiredupon certification of compliance (or, forfurnances that feed raw materialscontaining organic matter and thatreceive a time extension to certifycompliance, upon receipt of the timeextension.78

The Agency considered whether thehydrocarbon controls were redundant tothe operating requirements specifiedabove and concluded that HCmonitoring is needed to effectively

t We note, as discussed elsewhere in the textthe time extension will be conditional on, amongother things, HC (and CO) levels not exceeding aninterim limit established in the extension.




implement and enforce the controls onorganic emissions. Although theoperating requirements alone should beadequate to limit organic emissions,absent HC monitoring there would be nocontinuous verification that theoperating requirements were, in fact,adequate and that the owner/operatormaintained compliance with theoperating requirements.

Finally, the rule requires thathazardous waste be fired into a cementkiln itself to ensure that the waste is notintroduced at a location that may not beconducive to complete combustion ofthe waste. For example, cementcompanies have considered burninghazardous waste in the precalciner of acement kiln. Although such practicesmay prove during the permit process tobe acceptable, EPA has not testedemissions from a kiln burning waste atlocations other than in the kiln itself,and is concerned that completecombustion of organic constituents maynot be ensured. Thus, burning hazardouswaste in a cement kilns precalciner isnot allowed during interim status. (Thisrestriction is limited to cement kilnsbecause this is the only type of kiln ofwhich the Agency is aware wherehazardous waste may be fired at alocation that is clearly not designed foroptimum combustion conditions. Acement kiln precalciner is designedprimarily to achieve calcining of rawmaterials and may not provide adequatecombustion of hazardous waste.)

The special requirements do not applyto hazardous waste that is burned(processed] solely as an ingredient 71because such waste does not containsignificant levels of hazardous nonmetalconstituents (i.e., compounds listed inappendix VIII, part 261) and, thus,nonmetal emissions will not posesignificant risk to human health and theenvironment. (Metal emissions will beadequately controlled by today's ruleirrespective if where the waste is fedinto the system because metals arecontrolled by a PM control device.)Thus, emissions of nonmetal compoundsare not of concern when a waste isburned (processed) solely as aningredient. EPA considers a waste to beburned solely as an ingredient in a kilnif it is not burned partially as a fuel or

79 Under the RCRA hazardous waste regulatoryprogram. EPA considers a hazardous waste to beburned or processed as an ingredient if it is used toproduce a product. EPA considers a hazardouswaste to be burned or processed for materialrecovery if one or more constituents of the waste isrecovered as a product Nonetheless, the criteria arethe same for determining when a waste is burned(or processed) as an ingredient or for materialsrecovery versus when it is burned for the partialpurpose of energy recovery or conventionaltreatment.

for conventional treatment (i.e.,destruction). The Agency considers awaste that is fed to boilers andindustrial furnaces to be burned at leastpartially for energy recovery and not asan ingredient if it has a heating value of5,000 Btu/lb or greater, as-generated,and at least partially for treatment (i.e.,destruction) if it contains more than atotal of 500 ppm (by weight} of appendixVIII, part 261, nonmetal hazardousconstituents. See 54 FR at 43731-32where EPA discussed use of a 500 ppmstandard for distinguishing betweenrecycling activities tantamount toproduction and those constitutingconventional treatment.

The Agency notes in addition that itordinarily does not consider metal-bearing wastes hazardous wastes to beused as ingredients when they areplaced in industrial furnacespurportedly to contribute to producing aproduct. (The use of metal-bearingwastes for material recovery isdiscussed earlier in the preamble, andthis discussion does not deal with theissue of when such wastes are burnedfor legitimate material recovery inindustrial furnaces.) To be consideredlegitimate use as an ingredient, it wouldnormally need to be demonstrated toEPA (or an authorized State) pursuant to§ 261.2(f) that the hazardous metalconstituents in the waste are necessaryfor the product (i.e., are contributing toproduct quality) and are not present inamounts in excess of those necessary tocontribute to product quality. See 50 FRat 638 (Jan. 4,1985). This wouldnormally require some demonstrationthat these hazardous metal constituentsdo not render the product unsafe for itsintended use. (The other sham recyclingcriteria discussed frequently by EPAwould also have to be satisfied. See,e.g., 53 FR at 522 (Jan. 8, 1988).) Thetypes of uses of hazardous wastes inindustrial furnaces to produce waste-derived products of which the Agency isaware, such as using hazardous wastesto produce aggregate or cement (theAgency is not actually aware of cementkilns using hazardous wastes ostensiblyas ingredients, although some facilitieshave contemplated engaging in thepractice) do not appear to satisfy thesecriteria. In addition, the Agency notesthe discussion earlier in this preamble(in the context of hazardous waste usedas slurry water) to the effect that themore common and less valuable the rawmaterial the hazardous waste isreplacing, the more likely the activity isto be some form of surrogate treatment.

I. Special Metals Controls for Furnacesthat Recycle Collected ParticulateMatter

For reasons discussed in sectionIV.C.4 of this preamble, the final rulerequires owners and operators offurnaces (e.g., cement kilns, light-weightaggregate kilns with dry particulatematter (PM) control systems) thatrecycle collected PM back into thefurnace to implement the metalsemissions controls of § 266.106 (c) or (d)under one of the three alternativemethods. The discussion in sectionIV.C.4 of the preamble summarizesprocedures for certification ofcompliance under the methods. Forcertification of precompliance, thestandard procedures will be used forboth the "daily emissions testing"option, and the "conditioning prior tocompliance testing" option.Precompliance procedures are different,however, for the "monitoring metals incollected PM" method, as discussedbelow.

Under the "monitoring metals incollected PM" method, operating limitswill be established for all of theparameters listed in section VII.B. aboveexcept for the feed rate limit on eachmetal in total feedstreams. In lieu of thatparameter, the special procedures limitthe concentration of each metal incollected PM. See "AlternativeMethodology for Implementing MetalsControls" in Methods Manual forCompliance with the BIF Regulations(incorporated in today's rule asappendix IX of part 266).

For certification of precompliance, theowner/operator must estimate theenrichment factor for each metal usingengineering judgment or EPA prescribeddefault values. EPA default values are100 for mercury and 10 for all othermetals. The enrichment factors are thenused to calculate precompliance dustmetal concentration limits using theallowable emission rate for each metaland the applicable PM standard usingthe same procedures applicable forcertification of compliance. Daily (orweekly for noncritical metals) analysisof dust samples is required. If more than3 of the previous 60 samples fail, theowner/operator must notify theDirector. The owner/operator is thenallowed to burn hazardous waste for upto 720 hours before a revisedcertification of precompliance must besubmitted that revises the estimatedenrichment factors and establishesrevised precompliance dust metalsconcentration limits. The revisedenrichment factors must be based on'testing or engineering judgment using

7185




data or information not considered inthe original estimate.I. Recordkeeping

Over the period of interim status,facilities will be required to generateand maintain data and records designedto demonstrate routine compliance withestablished limits on operatingparameters. These records must besufficient'to allow a RCRA inspector toreview and evaluate recent and pastoperation of the facility for compliancepurposes. Records must be maintainedfor a period of three years or until anoperating permit is issued under§ 270.66, whichever is later.VIII. Implementation of Today's Rule

There are three types of treatment,storage, and disposal facilities (TSDF's)which may be affected by today's rule:(1) Facilities which are subject to RCRApermit requirements for the first time asa result of today's rule; (2) facilitieswhich are already operating underinterim status; and (3) facilities thathave been issued a RCRA permit. Thefollowing sections describe thecompliance obligations for facilities thathave units subject to permitting due totoday's rule.A. Newly Regulated Facilities

Prior to receiving a permit, newlyregulated facilities (i.e., facilities whichonly contain the types of units newlyregulated by today's final rule) mustqualify for interim status by the effectivedate of the rule in order to continuemanaging hazardous wastes in unitsnewly regulated by today's rule. Toobtain interim status, the eligible facilitymust meet three criteria: (1) On theeffective date of the BIF rule, the facilitymust be "in existence" with respect tohazardous waste burning or processingactivities; (2) within 90 days of the dateof publication, the owner or operatormust notify EPA or an authorized State(if not previously required to do so) ofthe facility's hazardous waste burning orprocessing activities; and (3) within 180days of the date of publication, theowner or operator must submit part A ofthe permit application.1. Definition of "In Existence".

To meet the definition of an existingfacility, the boiler or industrial furnacemust either be in operation burning orprocessing hazardous waste on orbefore the effective date of the rule, orconstruction of the facility (including thehazardous waste burning or processingequipment) must have commenced on orbefore the effactive date of the rule. See§ 266.103(a)(1)(ii). A facility hascommenced construction if the owner or

operator has obtained the Federal, State,and local approvals or permitsnecessary to begin physicalconstruction; and either:

(a) A continuous on-site, physicalconstruction program has begun; or

(b) The owner or operator has enteredinto contractural obligations--whichcannot be cancelled or modified withoutsubstantial loss-for physicalconstruction of the facility to becompleted within a reasonable time. See§ 270.2.

2. Section 3010 NotificationBIF owners and operators burning

hazardous waste fuels have alreadybeen required to notify of theirhazardous waste fuel activities underexisting § 2M6.35 and need not renotify.(See section 3010(a) which allows EPAto waive notification if the informationis considered unnecessary.) Althoughtoday's rule requires small quantityburners and owners and operators ofsmelting, melting, and refining furnacesto notify, this notification is not asection 3010 notice and so is not aprerequisite to obtaining interim status.

Facilities which have not submitted asection 3010 notification form to EPAmust do so by May 22, 1991. This is doneby completing a section 3010 notificationform and sending it to the appropriateEPA Regional Office. (See EPA form8700-12, dated 7/90. See 55 FR 31389,August 2, 1990 for a copy of the form.Notification instructions are set forth in45 FR 12746.)

3. Part A Permit ApplicationNewly regulated facilities must also

submit a part A permit application to theappropriate EPA Regional Office byAugust 21, 1991, which is the effectivedate of today's rule. (See 270.70(a) andEPA Form 8700-23, dated 1/90.)B. Interim Status Facilities

Interim status facilities that containunits newly regulated by today's rulemust file an amended part A permitapplication under 40 CFR 270.10(g) ifthey are to continue managinghazardous waste in these newlyregulated units. The facilities must filethe necessary amendments to EPA byAugust 21, 1991, the effective date of therule, or they will have to ceasemanagement of hazardous waste inthese units. In authorized states, thefacility should also send a copy of thesubmission to the State program.

Today's rule amends § 270.72 to allowinterim status facilities to add newlyregulated units as a change in interimstatus without prior Agency approval.The current procedures for the additionof new units in § 270.72(a)(3) require

Agency approval prior to making thechange. Section 270.72(a)(1) allows theaddition of newly listed or identifiedwastes, and any newly regulated unitsassociated with them, to be added to thepart A application without prior Agencyapproval. Today's addition of§ 270.72(a)(6) extends this ability to anynewly regulated unit. Today's rule alsoeliminates the reconstruction limit forthe addition of newly regulated types ofunits. (As noted earlier, the Agency-proposed this specific change for boilersand industry furnaces, but realized inthe course of implementing the proposalthat the problem was more endemic andcalled for a general solution.) Thisprovision is located in § 270.72(b)(7).

In order to add a unit as a change ininterim status under the new§ 270.72(a)(61, the owner or operatormust file the amended part A permitapplication by the effective date of therule that subjects the unit to regulation.

Technical Correction to § 270.73 (f),(g). In the course of developing today'srule, the Agency discovered thatparticular regulatory provisions dealingwith loss of interim status aremiscodified. See § § 270.73 (f), [g). Weare amending these provisions intoday's notice to match theimplementing statutory language. Theresult will be that neither boilers norindustrial furnaces, nor other unitswhich achieve interim status after Nov.7, 1984, are subject to the automaticstatutory loss of interim statusprovisions.

The 1984 HSWA amendmentsprovided that each facility whichachieved interim status prior to theeffective date of the amendments wouldautomatically lose its interim status on aspecified date, unless by an earlierspecified date the facility applied for afinal determination regarding theissuance of a permit (i.e., submitted partB of of its permit application. See RCRAsections 3005 (c)(2), (e)(2). The dates forpart B submission and loss of interimstatus vary according to whether thefacility is a land disposal facility,incinerator, or other facility. Id. Ofrelevance to today's technicalcorrection, HSWA provided that interimstatus for incinerators would terminatefive years after the enactment of HSWA(i.e., on November 8, 1989), unless thepart B application was submitted withintwo years after the enactment (i.e., byNovember 8, 1986). interim status forother non-land disposal facilities wouldterminate eight years after the HSWAamendments (i.e., November 8. 1992)unless the part B application wassubmitted within four years (i.e.,




November 8,1988). See RCRA section3005(c)(2).

EPA amended its regulations on July15,1985 to incorporate these and otherHSWA changes. See 50 FR at 28703.EPA's intention in promulgating theseamendments was simply to reflect thenew statutory provisions; for the mostpart, the Agency simply codified into theregulations the new HSWA language. Id.at 28703. In light of the largelyministerial nature of the regulations, andin view of the need to move quickly toincorporate HSWA, EPA publishedthese 1985 regulations withoutopportunity for public comment. Id. (TheD.C. Circuit eventually sustained thelegality of these procedures in UnitedTechnologies Corp. v. EPA 821 F.2d at714 (D.C. Cir. 1987).)

Section 270.73 (fJ, (g) sets forth thedates on which interim status forincinerators and other non-land disposalfacilities terminates if the facilities failto submit their part B applications.However, in contrast to the HSWAamendments, the sections by their termsapply to all incinerator and other non-land disposal facilities, instead of beinglimited only to those facilities which hadobtained interim status on November 8,1984, the date of the HSWAamendments. In fact, it is impossible forunits newly subject to regulation afterthe specified dates for submission ofpart B permit applications (such as theboilers and furnaces regulated bytoday's rule, or certain facilities newlysubject to regulation under the recentToxicity Characteristic rule) to complywith the rules as codified. EPA did notintend for these rules to deviate fromstatutory language. As the preamble tothe 1985 codification regulations stated.the Agency simply intended for section270.73 (f), (g) to reflect the HSWAtermination-of-interim status provisions.Id. at 28723.

The Agency is today making atechnical correction to these sections tocorrect this mistake, and to avoid theunintended (and possibly illegal) resultthat large classes of newly regulatedunits are ineligible for interim statusbecause they failed to submit part Bapplications at a time they wereunregulated. EPA is proceeding withoutproposing the correction for publiccomment, and believes that publiccomment is unnecessary, for thefollowing reasons: (1) This correctionsimply conforms the language of theregulations to the Agency's originalexpressed intent in promulgating the1985 regulations, which themselves werevalidly promulgated without theopportunity for comment; (2) thiscorrection simply conforms the

regulations to HSWA's plain language;(3) the amendment conforms theregulations to the Agency's actualpractice in implementing the regulationsand RCRA 3005(c)(2); (4) the amendmentis necessary to avoid rendering unitsnewly regulated after specified part Bpermit application submittal dates frombeing ineligible for interim status eventhough they meet all of the statutoryinterim status eligibility criteria; and (5)the amendment can be viewed as aninterpetative rule, which does notrequire prior notice and public comment.

C. Permitted FacilitiesSome permitted facilities contain

boiler and furnace units that are newlysubject to subtitle C regulation as aresult of today's rule. These permittedfacilities must therefore submit -permitmodifications to EPA Regional offices,and comply with federal permitmodification procedures in order to '

continue to manage hazardous waste inthese units. The modification will beprocessed under Federal permitmodification procedures rather thanauthorized state procedures becausethis rule is promulgated under HSWAauthority.80 However, because thepermit undergoing modification is mostlikely a jointly issued EPA-state RCRApermit, a copy of the modificationrequest should also be submitted to thestate if it is an authorized state.

1. Amendment to § 270.42(g)Today's rule contains a new permit

modification procedure in § 270.42 forthe addition of any newly regulatedwaste management units used tomanage hazardous wastes (see§ 270.42(g)). This two-step procedureessentially allows the permittee to notifythe Agency of its newly regulatedboilers and furnaces using the Class 1permit modification procedures, and tocontinue to handle hazardous wastes.Subsequently, the permittee must submita Class 2 or 3 permit modificationrequest to initiate a permanent changeto the permit. The self-implementinginterim status standards of § 266.103would apply until the permit wasmodified using the Class 2 or 3modification procedures. This newpermit modification provision onlyapplies to newly regulated units thatwere not previously subject to thepermitting requirements of subtitle C ofRCRA.

Today's new permit modificationprovision for newly regulated units is

0 oExcept. however, the provisions for sludgedryers, carbon regeneration units. infraredincinerators, and plasma arc incinerators are notpromulgated under HSWA authority.

essentially identical to the specialprocedure in J 270.42(g) for newlyregulated wastes. The purpose oftoday's amendment is to extend thesame opportunities and procedures thatare available for newly regulated wastestreams (and any units used to managethem) to those situations where the unitbecomes newly regulated in absence ofa new waste identification. (See 53 FR37922, September 28,1988.) EPA believesthat the same rationale applies to newlyregulated types of units, and is thereforeclarifying this provision in today's rule.

Without the procedure in § 270.42(g),the facility would need to obtain anapproved permit modification if thefacility were to continue managinghazardous wastes past the effective dateof today's rule, which establishesmanagement standards for boilers andindustrial furnaces. If the modificationswere not approved within six months,these facilities would be barred fromhandling hazardous wastes, disruptingthe ongoing operations of many of thesefacilities as well as other RCRAfacilities that would then need tomanage the wastes. As discussed below,EPA believes that the addition of aboiler or industrial furnace to a facility'spermit is a Class 3 modification.Because of the time allowed forpreparation of the modification requestby the facility and public participationin the permit modification procedures,the Agency would be unable to reviewand make a final determination on themodification request in the six monthperiod.

Today's technical correction rectifiesa potential inequity between permittedfacilities and newly regulated facilities.Newly regulated facilities are requiredonly to submit part A of the permitapplication, and submit the RCRAsection 3010 Notification form, ifnecessary, to obtain interim status. Bothactivities can be easily completed by theeffective date of today's rule, allowingthem to continue operations, whilepermitted facilities, who have undergonethe scrutiny of the permitting process,would likely be barred from doing so.

2. Procedures to Modify Permits

Under today's new procedures in§ 270.42(g), a unit that is "in existence"as a unit by managing hazardous wasteon or before the effective date of today'srule must submit a Class I modificationby that date. Essentially, thismodification is a notification to theAgency that the facility is managinghazardous wastes in these newlyregulated units. It could consist of arevised part A application form clearlyindicating all activities that are newly

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7188 Federal Register / Vol..56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

regulated as a result of today's rule. Aspart of the Class I procedure, thepermittee must also notify the publicregarding the modification within 90days of submittal to the Agency.

Next, within 180 days of the effectivedate, the permittee must submit a Class2 or 3 modification request to theAgency. It is at this time that thedetailed part B information must besubmitted. The Agency believes that theClass 3 permit modification proceduresare mostly likely applicable to theaddition of boilers 'or industrial furnaceunits. The Class 3 modification requiresan initial public notice by the facilityowner of the modification request, a 60day public comment period, and aninformal meeting between the ownerand the public within the 60 day period.After the end of the 60 day publiccomment period, the Agency willdevelop a draft permit modification,open a second public comment period of45 days and hold a public hearing. Afterthe public commnt period, the Agencywill make a final decision on themodification request.

Today's rule also amends appendix Ito § 270.42 to classify the permitmodifications for boilers and industrialfurnaces. Section L is revised to includeboilers and industrial furnaces withincinerators, and to specify additionalpermit conditions to conform withtoday's rule (and the conditions addedto incinerator permits under theomnibus authority of § 270.32(b)(2). Formore information on these permitmodification procedures, see 53 FR37912, September 28, 1988.

D. Addition of Storage Units as DirectTransfer Facilities ,That Obtain InterimStatus

As discussed in section XII.C of partThree of this preamble, the requirementsfor boilers and industrial furnaces arebeing promulgated under section 3004(q)of RCRA, which is a HSWA provision.As a result, under section 3006(g), EPAwill implement these requirements inboth authorized and unauthorized Statesuntil the State is authorized toimplement these requirements in lieu ofEPA. Based on comments receivedduring the rulemaking, EPA is awarethat many-interim status facilitiesnewly-regulated under this rule maywish to add storage units to theirfacilities in the future rather thancontinue direct transfer operations(direct firing of the burner from thetransport vehicle). Furthermore, EPArecommends that facilities install tanksand reduce or eliminate direct transferpractices because of the additionalhazards associated'with the practice. Asdiscussed in more detail below,-EPA

believes that such units can be added tothe facility without awaiting completepermitting.

1. Unauthorized StatesFacilities that wish to shift to storage

from direct transfer operations and thatare located in unauthorized states, willgenerally be able to add such units tothe facility as a change in interim statusunder 40 CFR 270.72(a)(3). In order toqualify for addition of units under thisprovision, the facility must: (1) Obtaininterim status for the boiler or industrialfurnace; and (2) submit a revised part Aapplication to the EPA Regional Officeprior to adding the storage units with ajustification for the change. BecauseEPA strongly encourages thediscontinuation of direct transferoperations at boilers and industrialfurnaces, EPA believes that the additionof storage units at such facilitiesconstitutes a change necessary to meetfederal requirements under 40 CFR270.72(a)(3)(ii). The Regional Office mustapprove the interim status change,unless it is covered by amended§ 270.72(a)(6) just discussed. Although40 CFR 270.72(b) limits the extent of anaddition that can be made duringinterim status, the addition of associatedstorage units under today's rule wouldbe exempt from this limitation pursuantto § 270.72(b)(2).

2. Authorized StatesInterim status facilities located in

authorized states that wish todiscontinue direct transfer operationswill also generally be able to add suchunits to the facility pursuant to 40 CFR270.72(a)(3). In states which are notauthorized to implement the HSWAstorage requirements for boilers andindustrial furnaces, the procedure foradding storage units at new interimstatus boilers or industrial furnaces isthe same as described above forfacilities located in unauthorized states.Because EPA is implementing both therule promulgated today and theassociated storage requirements in suchstates, the federal rules governingchanges in interim status apply to boththe boilers and industrial furnaces andthe addition of associated storagefacilities.

In states which have been authorizedto implement the HSWA storagerequirements for boilers and industrialfurnaces, facilities newly regulatedunder today's rule must comply with theauthorized state requirementsconcerning the addition of associatedstorage units. In some cases, theauthorized state may require the facilityto obtain a permit prior to constructingor operating such storage units.

E. Compliance with BIF VersusIncinerator Rules

Existing rules (see § 266.31(c)) requirethat cement kilns burning hazardouswaste that are located -in urban areasmust comply with the hazardous wasteincinerator standards. In addition,existing rules allow owners/Operatorsof any boiler or industrial furnace toobtain an incinerator permit. Theseprovisions exist because the Agency hadnot yet established regulatory controlsfor BIFs. In fact, the statutory provision(section 3004(q)(2)(c)) requiring thatcement kilns in urban areas be regulatedas incinerators states that the " * *regulations remain in effect until theAgency develops substantive standardsfor cement kilns burning hazardouswaste." Therefore, on the effective dateof the BIF rule, both of these regulatoryprovisions will be rescinded except asdiscussed below.

Commenters questioned whatregulations should more appropriatelyapply under three scenarios: (1) If a BIFis operating in interim status under thesubpart 0, part.265, incineratorstandards; (2) if a BIF has already beenissued an incinerator operating permitunder subpart 0, Part 264; and (3) if aBIF has previously submitted a part Bapplication for an incinerator permit andthe permit review process hasprogressed substantially by the effectivedate of the BIF rule. A BIF currentlyoperating under the interim statusincinerator regulations must complywith the BIF regulations on theireffective date in lieu of the incineratorregulations so that it is subject to themore stringent BIF rule. A BIF currentlyoperating under an incinerator permitwill continue under that permit until it isreviewed or the permit term otherwiseexpires. At that time, the BIF rule willapply. Although the Agency's generalpolicy is that BIFs are to be regulatedonly under the BIF rules, we believepermit officials should use theirdiscretion to determine whether to grantexceptions for the third situation giventhe protectiveness of the standards, andthe desirability of avoiding further delayand expense by having to duplicate thepermit process under these BIF rules.For example, if a BIF is operating underthe incinerator interim status standardsbut has submitted part B of theincinerator permit and the permitproceedings have progressedsubstantially, the Director may continueprocessing the permit (and issue it)under the incinerator standards and use




omnibus authority 6 1 to add conditionsto the permit as necessary to conformwith the BIF rule.IX. Permit Procedures

A. Part B InformationAs proposed on May 6, 1987 (52 FR

17015), § 270.22 provides specificinformation requirements for part B ofthe permit application. Paragraph (a)requires a trial burn to demonstrateconformance with the performancestandards of § § 266.104 through 266.107,except where the trial burn is waived.Although the regulatory language issubstantively the same as proposed, ithas been restructured for clarity, byspecifying the documentation requiredto support a waiver from each type oftrial burn: DRE trial burn, particulatematter trial burn, metals trial burn, andHCl/C12 trial burn.

In addition, the rule specifics under§ 270.22(a)(6) that owners and operatorsmay submit data from previouscompliance testing of the device, or fromtesting of similar boilers or industrialfurnaces burning similar wastes, in lieuof a trial burn provided that the data Isdetermined adequate and sufficientdocumentation of similarity is provided.

Paragraphs (b) through (e) were addedto J 270.22 to provide informationrequirements related to other regulatoryprovisions being promulgated today forboilers and industrial furnaces.Paragraph (d) requires informationdescribing the automatic waste feedcutoff system. Paragraph (e) requiresowners and operators using directtransfer operations to feed hazardouswaste from transport vehicles directly tothe boiler or industrial furnace to submitinformation supporting conformancewith the direct transfer standards at§ 266.111. Under paragraph {e), ownersand operators that claim their residuesare excluded from regulation under§ 266.112 must submit informationadequate to demonstrate conformancewith those provisions.

B. Special Forms of PermitsAs proposed, the final rule adds

§ 270.66 to subpart F of part 270. Thissection establishes special forms ofpermits (see discussion below) for newboilers and new industrial furnaces, and

s1 EPA notes that permit writers choosing toinvoke the omnibus permit authority ofI 270.32(b)(2) to add conditions to a RCRA permitmust show that such conditions are necessary toensure protection of human health and theenvironment and must provide support for theconditions to interested parties and accept andrespond to comment. In addition, permit writersmust justify in the administrative record supportingthe permit any decisions based on omnibus%uthority.

sets forth requirements for the variousperiods of operation under which aboiler or industrial furnace operates,depending on applicable trial burnrequirements. This section alsoestablishes trial burn procedures.Finally, this section discusses specialprocedures for permitting existingfacilities. Although these provisionswere described in the preamble to theproposal, at 52 FR 17016, they aredescribed briefly below, in order. tohighlight minor changes from theproposed requirements.

1. Permits for New Boilers and hdustrialFurnances.

Paragraph (b) specifies four operatingperiods of a permit for a new facility.The provisions have been restructuredfrom those proposed in recognition ofthe fact that all boilers and industrialfurnaces subject to a permit mustundergo some type of trial burn.Although a facility could conceivablymeet the requirements for a waiver ofthe DRE trial burn, particulate mattertrial burn, metals trial burn, and HCl/C12trial burn, all regulated facilities mustdemonstrate conformance with thecarbon monoxide, and where applicable,hydrocarbon limits or § 266.104.

In addition, minor revisions to thissection have been made to make thepermit process for new boilers andindustrial furnaces consistent with theway the hazardous waste incineratorpermitting process is implemented, i.e.,one permit with four periods ofoperations rather than an individualpermit for each period of operation.

Thus, the final rule provides forpermits addressing four periods ofoperation for all boilers and furnaces:The pre-trial burn period, the trial burnperiod, the post-trial burn period, andthe final permit period.

Conditions addressing compliancewith each performance standard forcorresponding waiver requirement) willbe set in the permit for each period ofoperation. Applicants must submit astatement with part B of the permitapplication that suggests the conditionsnecessary to operate in conformancewith the performance standards of§ §266.104 through 266.107. For thoseperformance standards for which a trialburn is required, the Director will usehis engineering judgment, andconsideration of the applicant'sproposal, in setting operating conditionsin the permit sufficient to meet theperformance standards. Once the trialburn data are available, they will beused to modify, if necessary, the finaloperating conditions in the permit. Forthose performance standards for whicha trial burn demonstration is not

required (for example, when theapplicant has chosen to comply withTier I of the metals limitations under§ 266.106(b)), appropriate conditions (inthe above example, metals feed ratelimits specified under § 266.102(e)(4))will be set for all periods of operation.

The pre-trial burn period begins withinitial introduction of hazardous wasteinto the boiler or industrial furnace andextends for the minimum time required,not to exceed 720 hours of hazardouswaste burning, to bring the device to apoint of operational readiness toconduct a trial burn. This period may beextended once by the Director if goodcause is shown. The trial burn periodcovers the period when the trial burn isconducted. This period is followed bythe post-trial burn period, which extendsfor the minimum time necessary to allowanalysis, data computation, andsubmission of the trial burn results andmodification of the permit by theDirector if necessary to reflect the trialburn results. Such modifications willproceed under the permit modificationprovisions at § 270.42.

Paragraph (c) specifies informationthat must be included in the trial burnplan. Paragraph (d) establishes trialburn procedures, including criteria forapproval of trial burn plans andrequirements for submission of trialburn data. Paragraph (e) establishesprocedures for selection of POHCs whena DRE trial burn is required. Finally,paragaph (f) established thedeterminations that the applicant mustmake based on the trail burn results--the data, analyses, and computationsthat must be submitted to supportconformance with the applicableemissions standards.

2. Permit Procedures for Interim StatusFacilities.

Applicants owning or operatingexisting boilers or industrial furnaceswill be permitted under § 270.66(g). Thisparagraph addresses submission of trialburn plans and trial burn data forexisting boilers and furnaces. Theseprovisions differ from the proposal inthat they specifically require that theapplicable trial burn data be submittedand considered prior to permit issuance.This language conforms with theJanuary 30, 1989 change to thehazardous waste incinerator regulations,promulgated at 54 FR 4286 providingclarification of this point.

X. Exemption of Small Quantity Burners

Section 3004(q)(2)(B) of RCRAprovides EPA with explicit authority toexempt from regulation facilities thatburn small quantities of hazardous

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wastes if the wastes are burned at thesame facility at which they aregenerated. The Administrator is toensure that such waste fuels are burnedin devices designed and operated in amanner sufficient to ensure adequatedestruction and removal to protecthuman health and the environment.

The Agency has carefully evaluatedthe risks posed by small quantityburning and concluded that aconditional exemption for small quantityburners should be allowed wherehazardous waste combustion posesinsignificant risk. A discussion of theorginal May 1987 proposal and thesubsejucnt October 1989 proposedrevisions is presented beluw.

On May 6, 1987 (52 FR 17034), theAgency proposed to exempt facilitiesthat burn small quantities of hazardouswaste that they generate on site becauseeven In the absence of regulatorycontrol, the health risk posed by suchburning would not be significant.Eligibility for the exemption would havebeen base on the quantity of wasteburned per month, established as afunction of device type and thermalcapacity. In order to be exempt, inaddition to restricting the quantity ofwaste burned, a facility was required tonotify the Regional Administrator that itis a small quantity burner, limit themaximum instantaneous waste firingrate to 1% of total fuel burned, andrefrain from burning acutely toxic wastecontaining dioxin.

On October 26, 1989 (54 FR 43730), theAgency proposed several revisions tothe exemption in the 1987 notice. Ratherthan establish hazardous waste quantitylimits as a function of device type andcapacity, EPA proposed quantity limitsthat vary as a function of effective stackheight. The exempt quantities proposedin October 1989, and promulgated today,include several changes to the riskassessment methodology. In particular,the quantities are based on evaluationof risks from hydrocarbon (HC)emissions instead of a PIC/POHC ratioas originally proposed. This change wasmade to better account for organicemissions from combustion. In addition.the procedures for evaluation offacilities with multiple stacks wererevised to reduce over-regulation inthese situations.

A. Response to Comments

Numerous commenters to the 1987 and1989 proposals objected to conservatismof the calculated quantity limits and/orthe 1% limit on hazardous waste firing.The commenters stated that theassumptions used In calculating theexempt limits are overly conservative,and that the 1% limit on firing of

hazardous waste is based on unrealisticand unjustifiable conclusions. Thecommenters, however, did not providedata or analysis to support theirarguments that assumptions used in thesmall quantity burner exemption (SQBE)calculations and conditions (includinglimits on the waste to be burned) forexemption eligibility were toorestrictive. Absent technical support foralternate approaches, the Agencycontinues to believe that the approachproposed in October 1989 is reasonableand appropriate. In addition, using lessconservative assumptions to derive theexempt quantities could allow relativelylarge amounts of hazardous waste to beburned, a result somewhat at odds withtha statutory language referring to small"quantities" of hazardous waste. See§ 266.108(a)(2) which limits themaximum hazardous waste firing rate atany time to 1% of the total fuelrequirements of the device on a volumebasis. See also § 266.108[a)(3) whichrequires the hazardous waste to have aminimum heating value of 5,000 Btu/lb,as-generated. to ensure that theexemption is limited to fuels as intendedby section 3004(q)(2)(B) and to ensureadequate destruction of toxic organicconstituents.

One commenter requested credit forthe presence of air pollution controldevices (APCDs). The Agency believesthat it is no appropriate to allow creditfor APCDs because, withoutrequirements for an oversight of theoperation and maintenance of thedevices, there is no assurance thatcollection efficiencies are being met.

Four commenters to the 1987 proposalurged EPA to delete the small quantityburner exemption. These commenterswere concerned that the large number ofboilers and industrial furnaces burninghazardous waste that do not have tomeet any design requirements wouldhave a detrimental effect on humanhealth and the environment. The Agencycontinues to believe that the exemptionis protective of human health and theenvironmet because it is health-based,incorporating quantity limits andconservative assumptions designed tobe protective regardless of size andlocation of the device, or conditions ofoperation.

Two commenters stated that theexemption should apply to facilities thatgenerate hazardous waste at off-sitefacilities under the same ownership andoperational control. The Agency isconcerned, however, that contrary toCongress's intent, this approach couldallow a large quantity generator todistribute their hazardous wastes insmall quantities to TSDFs (includingentities that are parent corporations.

joint ventures, subsidiaries of thegenerator, etc.) that would then burn thewastes without regulation.Consequently, the final rule limits theexemption to facilities that burn onlyhazardous waste generated on-site.

One commenter to the 1987 proposalurged the Agency to clarify that the 1%limit on the hazardous waste firing is tobe applied only to unmixed hazardouswaste fuel, not to a mixture ofhazardous and non-hazardous fuel. TheAgency acknowledges the ambiguity Inthe proposed rule language and intendedthe proposal to require that the quantitydetermination take into account only thehazardous waste fuel prior to mixingwith a nonhazardous waste fuel.Today's final rule contains language tothat effect and requires the exemptfacility to keep records to document thatthe quantity of hazardous waste prior tomixing with a nonhazardous fuelcomplies with the quantity limitations.

Six commenters to the 1989 proposalsuggested that quantity limits be basedon 1% of the total fuel burned and notthe stack height, which relies upondispersion only. The Agency, however,continues to believe that terrain-adjusted stack height is the importantcriterion, because it is possible thateven a 1% limit, with large dispersionand low stack height, could pose athreat to human health and theenvironment.

B. Basis for Today's Final Rule

In order to calculate allowableexempt quantities under today's rule,worst-case dispersion coefficients(based on incinerator modeling), and anHC unit risk factor of 2 X 10-

5 m3/ g(based on a 10 - 5 risk limit) wereassumed, as proposed in the October1989 supplemental notice. Allowableemission rates of hydrocarbons (HCs)were then back-calculated as a functionof effective stack height, terrain type,and land use. The assumption used inthis back-calculation was an HCconcentration in the stack gas of 150ppmv at 99.99% DRE. Finally, the exemptquantities were calculated using the J-ICemission rates and an empirically-derived ratio of combustion gas volumeto mass of waste. The most conservativeallowable emission rates calculated foreach stack height were then used as theestablished quantity limits.

A detailed description of themethodology used to derive quantitylimits for the exemption is available inthe docket for the supplemental notice.

As mentioned above, the use ofeffective stack height to determineeligible quantity limits reflects one ofthe revisions proposed in the October




26, 1989 supplemental notice. TheAgency notes that we have notestablished separate exempt quantitylimits for the different terrain types andland use classifications. Rather, therevised quantities are based onassumptions of terrain and land use thatresult in the lowest (i.e., mostconservative) exempt quantities. Webelieve that this conservative approachis appropriate given that there would beno EPA or State agency oversight of anoperator's determination of a facility'sterrain and land use classification. Somekey assumptions used to arrive at thequantity limits are described below.

EPA evaluated the risks posed byemissions of organic compounds, metals,and hydrogen chloride, the parameterscontrolled in the substantive regulationspromulgated in today's rule. 82 Theanalysis demonstrates that the risksposed by organic emissions from waste-as-fuel activities are overwhelminglydominated by the risks posed bycarcinogenic (as opposed tononcarcinogenic) waste constituents.Accordingly, the initial evaluationperformed in support of the smallquantity burner exemption focusedexclusively on carcinogenic risks, on theassumption that controls ensuringinsignificant risks from organiccarcinogenic emissions will ensureprotection against non-carcinogenicreleases. This assumption wasconfirmed by evaluating the potentialrisks from metals and hydrogen chloridethat would result when those quantitiesof waste indicated by the risk analysisfor organic carcinogens were burned.

The risks from burning smallquantities of hazardous waste aredetermined primarily by the followingfactors:

e Composition of the waste streambeing burned;

* Toxicities and concentrations ofhazardous constituents in the wastestream;

* Destruction and removal efficiencyachieved by the device;

* Local meteorology, which influencesthe amount of dispersion of stackemissions;

* Clustering and size of sources; and" The effective stack height of the

device.The values of these parameters can

and do vary widely. Reasonable, worst-case assumptions were made for theseparameters in the Agency's calculationsof exempt quantities and evaluation ofrisks. In the risk analysis, EPA assumedan acceptable cancer risk level of 1.0 X

" U.S. EPA, "Analysis for Calculating a deMinimis Exemption for Burning Small Quantities ofWaste in Combustion Devices", August 1989.

10 - 5 to an Individual residing for 70years at the ground level point ofmaximum exposure to reasonable,worst-case stack emissions. Reasonable,worst-case dispersion coefficients basedon effective stack heights were used.The dispersion coefficients were thosedeveloped in the risk analysis for theproposed amendments to the hazardouswaste incinerator regulations (See 54 FR43752 and 55 FR 17871). The dispersioncoefficients differ by terrain type, landuse, and effective stack height. Separatecalculations were made for noncomplexand complex terrain and urban and ruralland use, resulting in three different setsof quantity eligibility limits for eacheffective stack height. The rationale forthe assumptions used in the riskanalysis is discussed below.

1. Composition of Hazardous WasteStream

Composition data on hazardouswaste-derived fuels is scarce.Information gathered by the mailquestionnaire survey and other industrycontacts indicate that most of thematerials burned are organic solventsthat are usually classified as hazardousbased on ignitabiity and/or toxicity.The actual concentrations ofcarcinogens in wastes burned by 21facilities during EPA's field testingprogram for boilers and industrialfurnaces ranged from 0 to 17% with anaverage of approximately 4%.

The quantity of PICs measured in EPAtest burns was found to be independentof specific POHC species and was afunction of hydrocarbon (HC) content ofthe fuel only. This Is supported bycomparisons made by MRI of PICs fromhazardous waste and fossil fuelcombustion. Since it is impossible todifferentiate between the PICs from fueland those from hazardous waste duringmost tests, it was assumed that theboilers in the EPA test burns were usingfuels of 100% HC and all PICs are theresult of hazardous waste burning.Additionally, HC emissions arepresumed to be an acceptablemeasurement of PICs; historic dataindicate that HC measures from 75 to95% of all PICs emitted.

The hazardous waste was assumed tocontain concentrations of cadmium,chromium, nickel, and lead that wereobtained from the state sampling reportsof the Keystone Cement Company.Arsenic, barium, and mercuryconcentrations were based on 90thpercentile levels from the EngineeringScience Background Document.

2. Toxicity of Hazardous Constituents

The average unit risk of those PICsthat were identified during EPA trialburns was 1.0X10-5ms/jg. However, it

is likely that the PICs resulting fromincineration under the 99% DREassumption for the small quantity burneranalysis would have a higher toxicitythan those measured under the 99.99%DRE in the EPA boiler tests. EPAtherefore estimates the unit risk for totalHCs to be 2.0X10 -

5m /pg. Thiscorresponds to a carcinogenic potencyof Qi* = 0.07 for hydrocarbons (HC). Asexplained in the October 1989 notice,this potency factor was used rather thana Qi* value of 1.0 for products ofincomplete combustion as originallyproposed in the May 6, 1987 proposedrule because the Agency was concernedabout possible nonconservative featuresof PIC estimation. (See 54 FR 43730.)

3. Destruction Efficiency

The burner destruction efficiencydetermines the quantity of unburnedhazardous wastes that will be emittedfrom the stack. Assumed values forboiler and furnace performance wereselected based upon review of test datagenerated in support of this rule andbased on the professional judgment ofAgency staff members familiar with thedestruction and removal efficiencies(DRE) typically achieved by boilers. Itwas assumed that, in the worst case,boilers and furnaces would only achieve99% DRE 8 of organic constituents. Thisrepresents a very poorly performingcombustion device. In fact, as explainedpreviously, most boilers and furnacescan be expected to achieve 99.99% DREof organic waste constituents even whenoperated under less than optimalconditions.

4. Assumptions Regarding Metals andChlorine in Waste Fuels

A similar reasonable, worst-caseanalysis was performed to evaluate thepotential risks posed by emissions oftoxic metals (including carcinogens) andhydrogen chloride from small quantityburners. As a result, it was determinedthat, at the volume cut-offs specified bythe exemption and the assumed wasteconcentrations as discussed above,metals emissions caused by cofiring ofhazardous wastes would not pose asignificant risk. The analysis alsoconsidered hydrogen chloride emissionsassuming a chlorine content of 50% inthe hazardous waste fuel. The chlorine

93 We note that we assumed 99% DRE to derivethe small quantity burner exempt quantities ratherthan the 99.9% that the owner/operator mustassume under the low risk waste exemption of§ 266.109 because monitoring of CO is not requiredfor the small quantity burner exemption to ensurethat good combustion conditions are maintained.CO monitoring Is required under the low risk waiverof the DRE trial burn.

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content in actual hazardous wastesseldom exceeds 3%; however, thehighest chlorine content measured in ahazardous waste fuel fired in a boiler ofwhich EPA is aware was 43%. Predictedground level concentrations of HCI alsodid not exceed the reference aidconcentrations.

The assumptions used to determinethe effect of local meteorology/dispersion and the clustering of sources(stacks at the facility) are discussed inthe following section.

C. How the Exemption Is Implemented

1. Use of Terrain-Adjusted EffectiveStack Height

In the 1987 proposal, the Agency useda set of assumptions about localmeteorology, dispersion modeling,terrain conditions, etc., to determineeligible quantity limitations. Asmentioned above, today's rule usesterrain-adjusted effective stack heightalong with the most conservativeassumptions of terrain and land use todetermine quantity limits for exemptioneligibility. See § 268.108.

2. Multiple StacksAs explained in the October 1989

notice, in today's final rule the exemptquantities for a facility with multiplestacks from boilers or industrialfurnaces burning hazardous waste arelimited according to the followingequation:

n Actual Quantity BurnedwYZ <1.0

1=1 Allowable Quantity Burnedw

Where:" n means the number of stacks" Actual Quantity lurned. means the

waste quantity per month burned instack "i"

" Allowable Quantity Burned, means themaximum allowable exempt quantity forstack "i"

For example, if a site had two stackswith effective stack heights (ESH] of 30and 10 meters, the following equationwould hold:

X Y- + - <1.0140 40

Where:* 140 and 40 are the exempt quantities

from § 266.108 for stack heights of 30 and10 meters, respectively

* X is the waste quantity burned in thedevice with the 30 meter stack

* Y is the waste quantity burned In thedevice with the 10 meter stack

In this example, if Y is burning 15gallons/month, then X could burn nomore than 87.5 gallons/month.

D. Wastes Ineligible for Exemption

Boilers and furnaces burninghazardous waste fuels containing orderived from any of the following _dioxin-containing hazardous wastes arenot eligible for the exemption: EPAHazardous Waste Nos. F020, F021, F022,F023, F026, and F027. See§ 266.108(a)(4). Given the toxicity ofthese wastes, EPA does not believe it isappropriate to exempt facilities burningthem from regulation. Hazardous wastefuels containing or derived from thesedioxin-containing wastes must beburned at a 99.9999% destruction andremoval efficiency (DRE). We cannotexpect boilers and furnaces to achievethat level of DRE when operatingoutside of the Agency's regulatorysystem.

E. Exemption of Associated Storage

Hazardous fuel storage practices priorto burning vary from site to site. Manyfacilities burning relatively largequantities of hazardous waste fuels holdthe fuels in a storage system and thenpump the waste fuels through adedicated line into the combustion zoneof the boiler. Other facilities mixhazardous waste fuels with other fuels(typically virgin fuel oil) in a storage/mixing tank prior to burning the blendedmaterial. These tanks are not feasiblyemptied of hazardous waste every 90days and so are in most cases ineligiblefor the generator accumulationprovisions In § 262.34.

Under today's rule, facilities storingunmixed hazardous waste fuels areresponsible for complying with allapplicable standards for the storage ofthe hazardous waste fuel. Owners andoperators that are eligible for the smallquantity burner exemption and who mixtoxic hazardous waste fuels would,however, be exempt from the storagestandards after such mixing, asproposed. See § 266.101(c)(2). The basisfor this exemption is discussed below.

The Agency is promulgating anexemption for storage of such storage/mixing tanks (for small quantityburners] in order for the small quantityburner exemption in section3004(q)(2)(B) to have a practicalapplication. Congress evidentlyenvisioned a class of facilities capableof burning small amounts of hazardouswastes safely absent regulation andviewed such burning as a superiormeans of managing these small amountsof waste. Furthermore, assuming that

small quantity waste storage isconducted safely, the Agency assumesthat Congress also envisionedexemption of the storage sincepermitting storage would discouragesafe on-site burning just as much asregulating the burning itself.

We believe that storage of smallamounts of hazardous wastes mixedwith virgin fuels would pose nosignificant incremental risks overstorage of the virgin fuels. The monthlyvolumes of hazardous waste fuelcovered by the small quantity burnerexemption, for example, represent lessthan 1% of the fuel flow rate throughthese tanks. Under these circumstances,we think the statutory exemption canreasonably be read to encompass thislimited class of storage practices aswell.

We note further that the Agency isstudying other situations wherehazardous waste-containing mixturesmay not be appropriately subject toregulation and will consider whether toissue rules addressing the issuegenerically. It appears to us justifiable toaddress the question for the limitedclass of burning facilities in advance ofother types of situations becauseCongress has singled out small quantityburning facilities for exemption whereappropriate. We note further that to theextent these small quantity waste-virginfuel tanks are underground storagetanks (as defined-in RCRA section9001(1)], they would be subject toregulation under Subtitle I if theycontain petroleum.

F. Notification and RecordkeepingRequirements

As proposed in the October 26, 1989supplemental notice, the final rulerequires (conditionally) exempt smallquantity burners to provide a one-timewritten notification to EPA (see§ 266.108(d)) of their status as a smallquantity burner and a certification thatthey are in compliance with therequirements of § 266.108. To assistenforcement efforts, the owner oroperator must also indicate in thenotification the maximum allowablequantity that may be burned per monthas provided by § 266.108(a)(1). Inaddition, the final rule requires smallquantity burners to keep records todocument that they comply with theconditions of the exemption including:quantities of hazardous waste burnedper month; quantities of hazardouswaste and other fuels burned at anytime to demonstrate conformance withthe 1% hazardous waste firing rate limit;and heating value of the hazardouswaste.




X. Exemption of Low-Risk Waste fromDRE Standard and Particulate MatterEmission Standard

The final rule defines two types of"low-risk" wastes: (1) waste that is lowrisk with respect to feed rate ofhazardous (i.e., appendix VIII, part 261)nonmetal constituents and, thus, isexempt from the requirement todemonstrate 999% DRE; and (2) wastethat is low risk with respect to bothnonmetal constituents and metals (i.e.,the waste meets the Tier I feed ratelimits for metals provided by§ 266.106(b)) and, thus, is exempt fromboth the DRE standard and the 00 gr/dscf particulate standard. See § 266.109.

The following sections explain theseexemptions and how they operate.A. Exemption from Compliance with theDRE Standard

In the May 6, 1087 proposed rule, theAgency proposed a risk-based, site-specific waiver of the DRE trial burnand the flue gas CO limits for facilitiesburning waste that poses insignificanthealth risks absent those controls (52 FR17002). Today's final rule retains theexemption from the DRE standard, butrequires the facility to monitor COcontinuously and to comply with theTier I PIC controls of § 266.104(b) (Le.,CO cannot exceed the 100 ppmv limit onan hourly rolling average basis).

In the 1987 proposal. EPA explainedthe basis for the DRE exemption forboilers or industrial furnaces that burnlow-risk waste (52 FR 17002). Afterfurther consideration, however, theAgency believes that controls onemissions of PICs are needed. This isbecause a waste with low levels of toxicorganic constituents can nonethelesspose signficant health risk if it is burnedunder poor combustion conditionsconducive to formation of PICs. ToxicPICs can form from poor combustion ofnontoxic organic compounds.

The final rule does not allow a burnerto operate under the alternative CO limitprovided by I 266.104(c), which allowshigher CO levels provided that HClevels do not exceed 20 ppmv, becausethe Agency believes that only thosedevices operating under bestdemonstrated technology combustionconditions should be granted anexemption from the DRE requirement.(We note that this is consistent with theCO restriction for the automatic waiverof the DRE trial burn for boilersoperating under the special operatingconditions provided by § 266.110.)Devices operating at CO levels above100 ppmv on an hourly rolling averageare not operating under bestdemonstrated technology combustion

conditions even if they can show thathydrocarbon levels do not exceed 20ppmv (or the HC limit established under§ 266.104n)f. As discussed at proposal(see 54 FR 43723 c.3), the 20 ppmv HClevel represents a demarcation betweengood and poor combustion conditions.HC levels under best demonstratedtechnology combustion conditionswould generally be less than 5 ppmv onan hourly rolling average basis.

B. Exemption from Compliance with theParticulate Standard

Today's final rule provides a waiverof the particulate standard for facilitiesthat both obtain the DRE standardwaiver and meet the Tier I requirementsfor all metals. (Because the PM standardguards against risks from both adsorbedorganic compounds and metals, onlyfacilities with waste that is low risk forboth organic constituents and metals areeligible for the PM waiver.)

The basis for imposing a particulatestandard on boilers and industrialfurnaces firing hazardous waste, asexplained in the October 26, 1989supplemental notice (54 FR 43719), isprimarily the concern over adsorption oftoxic organics and metals onto theemitted particulates. Consequently, theAgency believes that an exemptioni fromthe particulate standard for boilers andindustrial furnaces is appropriateprovided that the facility candemonstrate that emissions of toxicorganics and metals do not poseunacceptable human health risks.

C. Eligibility RequirementsThree eligibility requirements for the

low-risk waste exemption were detailedin the 1987 proposed rule. Manycommenters objected to the first of theserequirements, that 50 percent of the fuelfired in the boiler or industrial furnacemust consist of oil, natural gas, coal, orother fossil fuels derived from thesefuels. These commenters requested thatEPA allow the cofiring of various otherfuels, including tall oil, off-specificationfuel oils, and wood chips.

Although some of these fuels mayprovide a hot, stable flame that willsupport good combustion, the Agency Isconcerned that others may not. Intoday's rule, the Agency is requiring forthis exemption the same conditions onthe primary fuel as required for thespecial operating requirements forboilers seeking the automatic waiverfrom a DRE trial burn (see section ILA.3of part three of this preamble): aminimum of 50% of the fuel fired to theboiler must be high quality "primary"fuel consisting of fossil fuels or fuelsderived from fossil fuels, tall oil, or, ifapproved by the Director on a case-by-

case basis, other nonhazardous fuelcomparable to fossil fuel, and all suchprimary fuels must have a minimum as-fired heating value of 8,000 Btu/lb.

The two remaining eligibilityrequirements, that the hazardous wastemust have an as-fired heating value of atleast 8,000 Btu/lb, and that the wastemust be fired into the flame zone of thecombustion chamber, are beingpromulgated as proposed in 1987. Thereasons for these requirements are thesame as discussed in section II.A.3 ofpart three of this preamble in thecontext of the automatic waiver of theDRE trial burn for boilers.D. How the Low-Risk Waste ExemptionWorks

1. Constituents of Concern

The low-risk waste exemption isintended to exempt a waste from eitheror both the DRE standard and theparticulate standard if the owner/operator demonstrates that, absentregulatory controls (i.e., under areasonable, worst-case emissionsscenario), emissions from the facilitywill not result in ambient levels of toxicorganic compounds and/or metals thatexceed acceptable levels. The organicconstituents of concern are thehazardous organic compounds listed inappendix VIII of 40 CFR part 261 and themetals of concern are the 10 regulatedmetals.

2. Estimation of Worst-Case Emissions

The requirements for estimatingworst-case emissions were discussed inthe May 1987 proposed rule and arebeing promulgated in today's rule withslight modifications.

To estimate reasonable, worst-caseemissions of toxic organic constituentsin hazardous waste fuel, an owner oroperator must: (1) Identify everynonmetal appendix VIII constituent thatcould reasonably be expected to befound in the waste: and (2) assume areasonable, worst-case destruction andremoval efficiency (DRE) for eachconstituent of 99.9 percent in calculatingthe worst-case emissions (byconsidering waste concentration andfeed rate) from the stack for eachconstituent. This assumed DRE of 99.9percent is less conservative than theproposed 99 percent assumption in the1987 notice. The Agency is making thischange in response to the manycommenters who objected to the 99percent DRE assumption. Specifically,the commenters' objection was that 99.9percent was the worst DRE measured bythe Agency in its nonsteady-state testingof boilers operated under intentionally

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upset (i.e., high CO and smoke)conditions. The Agency believes thatchanging the assumed DRE from 99percent to 99.9 percent is justifiedbecause today's rule, unlike the 1987proposal, does not provide a waiver ofthe continuous CO emission monitoring(CEM) requirements. Compliance withcontinuous CO monitoring requirementswill ensure that these devices do notoperate under upset conditions and willachieve a DRE of at least 99.9 percent.

The Agency has eliminated theproposed requirement that emissions ofproducts of incomplete combustion(PICs) be estimated using a ratio of PICsto principal organic hazardousconstituents (POHCs). As explained inthe April 1989 notice (54 FR 43730), useof the PIC:POHC ratio may not be aconservative method for estimating PICemissions.

An estimate of worst-case emissionsis not necessary for metals. To beeligible for the exemption from theparticulate standard, the Waste must below-risk with respect to organiccompounds and must meet the Tier Imetals feed rate limits. See § 266.106(b).Those metals feed rate limits assumethat all metals fed into the device areemitted.3. Dispersion Modeling

Dispersion modeling must be used topredict the maximum annual averageground level concentration of each toxicnonmetal compound In the waste usingprocedures identical to those required toimplement the Tier Ill metals controls.See 266.109(a)(2)(iii)(A).

4. Acceptable Ambient LevelsPredicted maximum annual average

ground level concentrations of eachtoxic nonmetal compound may notexceed levels the Agency proposed asacceptable for purposes of this rule. Theacceptable ambient concentrations weredeveloped for carcinogenic andnoncarcinogenic compounds using thesame procedures used to develop theRACs and 10- 5 RSDs for the 10 toxicmetals.

To demonstrate that thenoncarcinogenic nonmetal compoundslisted in appendix IV of the rule do notpose an unacceptable health risk, thepredicted ground level concentrationscannot exceed the levels established inthat appendix.

To demonstrate that the carcinogenicnonmetal compounds listed in appendixV of the rule do not pose anunacceptable health risk, the sum of theratios of the predicted ground levelconcentrations to the levels establishedIn the appendix cannot exceed 1.0. Thisis because the acceptable ambient levels

established in appendix V are based ona 10- 5 risk level. To ensure that thesummed risk from all carcinogeniccompounds does not exceed 10- 5 (i.e., 1in 100,000), the sum of the ratiosdescribed above must be used.• To demonstrate that other compounds

for which the Agency does not haveadequate health effects data to establishan acceptable ambient level are notlikely to pose a health risk, the predictedambient level cannot exceed 0.1 gg/m.This is the 5th percentile lowestreference air concentration for thecompounds listed in appendix IV of therule.

5. Constituents with Inadequate HealthEffects Data

At the time of the 1987 proposal, theAgency had data adequate forestablishing RACs and RSDs for onlyabout 150 of the over 400 compoundslisted-in appendix VIII, part 261. In thepreamble to the May 1987 proposal, EPAstated that, to be eligible for theexemption, health effects data (i.e.,RACs and RSDs) must be available foreach constituent in the waste. Inresponse to comments concerning theinadequacy of current health effectsdata to establish a RAC or RSD for alarge number of compounds, we haveestablished in today's rule aconservative RAC value for suchconstituents determined as the 5thpercentile lowest RAC for all of thenonmetal appendix VIII, part 261,constituents---0.1 jgg/m 3 (see note toappendix IV of the final rule). EPAbelieves that this approach will beprotective of human health and theenvironment and will not unreasonablyrestrict owners/operators fromeligibility for the exemption.XII. Storage Standards

A. Permit Standards for StorageI Under the administrative controls for

hazardous waste marketers, burners,and blenders of hazardous waste burnedin boilers and industrial furnacespromulgated on November 29, 1985, andcodified in subpart D of part 266, EPAsubjected existing burner storagefacilities (effective May 29, 1986) to onlythe interim status standards of part 265.The permit standards of part 264 werenot applied to existing storage facilitiesin order to avoid two-stage permitting,given that today's rule for permittingboiler and industrial furnace facilitieswas under development at that time.The Agency wanted to avoid requiring aboiler or Industrial furnace owner oroperator to obtain a permit for theirhazardous waste fuel storage facilityand to soon thereafter obtain another

permit for operation of the boiler orindustrial furnace under today's rule.

Today's rule does, therefore, subjectsuch existing burner storage facilities tothe permit standards of part 264. SeeJ 268.101(c).

Numerous comments on the May 6,1987 proposed rule to subject burnerstorage units to the permit standards ofpart 264 agreed that the interim statusstandards currently in force are notadequate and permit standards areneeded. Several commenters wereconcerned about the potentialmishanding of waste fuels stored on-sitein and around residential areas. Onecommenter requested that preburntransport and storage regulations forhazardous waste apply to all hazardouswaste blends, mixtures, or dilutedhazardous materials.

With the promulgation of today's rule,all hazardous waste storage units willbe subject to applicable part 264 and 265standards. Since hazardous waste.storage units standards are designed tobe protective of human health and theenvironment regardless of the locationof the facility, on-site storage associatedwith boilers and industrial furnacesburning hazardous waste is notrestricted to areas in or aroundresidential areas. These standards applyto the storage of any hazardous wasteblends, mixtures, or dilutions that willbe burned at these facilities, due to the"mixture rule" of 40 CFR 261.3. Whereasnonindustrial boilers were previouslyprohibited from burning hazardouswastes unless they were operated inconformance with the incineratorstandards of subpart 0 of parts 264 or265, today's rule eliminates thedistinction between industrial andnonindustrial boilers. Consequently,today's rule establishes standards thatare protective when hazardous waste isburned in any boiler.

One commenter recommended thatthe final rule allow the 90-day "on-site"accumulation provision to includewastes received at the BIF from off-site,company-owned locations. The 90-dayaccumulation provision referred to bythe commenter is contained in 40 CFR262.34(a) and only applies to generatorsof hazardous wastes. The Agency doesnot intend to apply this provision tohazardous waste treatment, storage, ordisposal facilities.

B. Consideration of Requirement forLiquid Waste Fuel Blending Tanks

In the October 26, 1989 supplementalnotice, the Agency requested commenton a requirement that all boiler andindustrial furnaces use blending andsurge storage tanks (i.e., other than other

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modes of waste fuel transfer) to avoidflow interruptions and wasteAtratification which could affect theability of a combustion device to meetperformance standards. The majority ofcommenters opposed requiring blendingand surge storage tanks for BIFs andsuggested that such a requirementwould not be necessary to ensurecompliance with performancestandards. Several commenters believedthat a uniform requirement for tanks,containers, and/or surge tanks may notbe universally appropriate. Thesecommenters noted that some secondarymaterials such as lead acid batteries,flue dust, and various scraps and slagscannot be transferred to furnaces from atank or container system. Anothercommenter suggested that in someinstances, such as feeding incompatiblewastes, direct transfer may bepreferable due to health and safetyconcerns. A few commenters concurredwith this view, but felt that storage andblending tanks should be required in allother instances. One commentersuggested that storage tanks should berequired only if transport vehicles donot meet Department of Transportationrequirements, secondary containment isnot used in transfer operations, and ifoperations are not covered by site-specific contingency or SPCC plans. Onecommenter agreed that hazardouswastes should generally be fed fromstorage tanks and supported a final rulethat would allow a "window ofopportunity" to install storage tanks,thus providing an incentive for acompany to reduce their reliance ondirect burning from transport vehicles.

In today's rule, the Agency is notrequiring storage and blending tanks forboilers and industrial furnaces burninghazardous waste because we continueto believe that such tanks are notrequisite to demonstrating conformancewith the emission standards of§ § 266.104 through 266.107. However, asindicated in the supplement to theproposed rule, EPA believes thatfacilities that install blending andstorage tanks may be better able tocontrol flow interruptions and wastestratification. Consequently, boilers andindustrial furnaces with blending and/orstorage tanks may operate with greaterefficiency and thereby may more readilymeet performance standards foremissions.

We also note that, once an owner/operator is In interim status, the part Aapplication may be revised to convertfrom direct transfer operations to theuse of storage units. See discussion insection VII.D of Part Three of thepreamble.

C. Standards for Direct TransferOperations

In the October 26, 1989, supplement tothe proposed rule, EPA identifiedpermitting authorities' concerns aboutthe practice of feeding hazardous wastefuels directly from transport vehicles toboilers and industrial furnaces. Theseconcerns included: (1] The potential forfires, explosions, and spills duringtransfer operations; and (2) thestratification of waste in the transportcontainer and the potential for wastefuel flow interruptions which, in turn,could affect the ability of the burner toconsistently provide efficientcombustion of the waste. EPA requestedcomment on two approaches to regulatedirect transfer operations. One approachwas for permit writers to use the RCRAomnibus authority to establishadditional permit conditions asnecessary to ensure adequate protectionof human health and the environmentfrom such operations. The otherapproach was to require that facilitiesburning hazardous waste use blendingand surge storage tanks to avoid theflow interruptions and wastestratification, which would addresspermit writers' concerns.

In the April 27, 1990 Federal Registernotice, EPA noted that commenters onthe October 1989 notice stated thatcontrols on transfer operations wereneeded during interim status. As aresult, the Agency requested commenton the need and appropriateness ofregulating direct transfer operationsunder interim status standards forcontainers and tank systems of subpartsI and J of part 265. EPA receivednumerous comments in response tothese solicitations. The majority ofcommenters recommended that EPAallow direct transfer with propercontrols and restrictions, such as: (1)Allow direct transfer approval forfacilities granted interim status or aRCRA operating permit; (2) establishdirect transfer standards similar tosubparts I and J of 40 CFR part 265 forfacilities with a contingency or SPCCplan; and (3) allow direct transfer duringtest burns alone. Some respondentssuggested that instead of allowing directtransfer, EPA should require storage andblending tanks for all facilities burninghazardous waste.

The Agency is today promulgatingstandards regulating direct transferoperations. See § 266.111. The Agencybelieves that these standards willadequately address potential risks tohuman health and the environment.

EPA considers direct transferoperations to be a part of the hazardouswaste firing system, not a storage

activity. Hence, facilities that are notsubject to the burner standards of§ § 266.102 (permit standards) or 266.103(interim status standards) are notsubject to the direct transfer standards.Examples of facilities not subject to thedirect transfer standards are smallquantity burners exempt from regulationunder § 266.108, metals reclamationfurnaces deferred under § 266.100(c),and coke ovens exempt under§ 266.100(b)(4).

These direct transfer standardsreference extensively the subpart Icontainer standards and the subpart Jtank standards of parts 264 and 265 andwill apply equally to facilities operatingunder a permit as well as thoseoperating under interim status. Theregulations address the area in whichtransport vehicles are located andpiping and other ancillary equipment(termed "direct transfer equipment" intoday's rule) used to transfer waste fromthe vehicle to the burner. The standardsprovide general operating requirementsand controls on equipment integrity,containment and detection of releases,response to leaks or spills, design andinstallation of new direct transferequipment, and closure.

1. General Operating Requirements

Facilities that directly transferhazardous waste to boilers andindustrial furnaces from transportvehicles must comply with generaloperating requirements that specify safemanagement practices for handlingincompatible wastes, spill preventioncontrols, and automatic waste feedcutoffs. These general operatingrequirements apply to bothcontainerized and bulk hazardouswaste. General performance standardsfor safe operation in today's rule includemeasures for conducting direct transferoperations such that fire, explosion,violent reactions, and other conditionsthat could threaten human health or theenvironment do not occur. Directtransfer from open-top containers isprohibited. Direct transfer equipment,which is any device that distributes,meters, or controls hazardous wasteflow between a transport vehicle and aBIF, must also be closed except whennecessary to add or remove the waste.Safe management practices for handlingincompatible wastes are also required.Transport vehicles or direct transferequipment holding ignitable or reactivehazardous waste must be located atleast 50 feet from the receiving facility'sproperty line.

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2. Inspections and Recordkeepin 8

All equipment and areas where directtransfer occurs must be inspected hourlyfor leaks during direct transferoperations. Control equipment, directtransfer equipment monitoring data, andother equipment ensuring compliancewith direct transfer standards must alsobe inspected hourly. Finally, the ruleprovides recordkeeping requirements todocument results of inspections.

We note that only daily inspection isrequired under subpart J of parts 264and 265 for tank systems (i.e., piping,valves and other direct transferequipment). EPA is requiring hourlyinspections of direct transfer operationsbecause, unlike tank systems that usehard piping, direct transfer operationsuse flexible hoses and quick changecoupling devices that have a greaterpotential for leaks or spills.

3. Equipment Integrity

Equipment integrity requirementsaddress direct transfer equipment (e.g.,piping or conveyors from the transportvehicle to the burner). The standardspromulgated today require the transferof waste to other equipment ifequipment holding hazardous wasteleaks or is in poor Condition, and specifysafe management practices fortransferring wastes to other containersor transport vehicles. An assessment isrequired of existing direct transferequipment that does not meet thesecondary containment requirementsdiscussed below to determine if thedirect transfer equipment is leaking orunfit for use and must be certified by aqualified, registered professionalengineer. If equipment is found to beleaking or unfit for use, the owner/operator must comply with therequirements addressing responses toleaks or spills.

4. Containment and Detection ofReleases

The rule requires secondarycontainment for underground directtransfer equipment. See § 266.111(e)(1).Inspections and leak tests of directtransfer equipment and recordkeepingrequirements are also required. Existingdirect transfer equipment subject to thesecondary containment requirements of§ 265.193 (by reference in § 266.111(e)(1)of today's rule) must comply with thosesecondary containment requirementswithin two years after the effective dateof the rule. EPA believes that two years(30 months from promulgation) is areasonable amount of time to enableowners and operators to retrofit existingequipment with secondary containmentas necessary given that direct transfer

operations generally do not involve theuse of extensive equipment subject to.secondary containment.

5. Response to Leaks or Spills

Action required to be followed in theevent of a leak or spill are based onthose required in subpart J, part 265. See§ 266.11(e)(5). Should a leak or spilloccur, equipment use must cease (toprevent the flow or addition of wastesinto the direct transfer equipment orsecondary containment system) and thesystem must be inspected to determinethe cause of the release. The waste mustbe removed from the direct transferequipment or secondary containmentsystem and visible releases to theenvironment must be contained. In theevent of a leak or spill, the Director mustbe notified of the incident In writing.Secondary containment, repair, orclosure of the leaking equipment, andcertification of major repairs must beprovided.

6. Design and Installation of NewEquipment

New direct transfer equipment mustmeet the design and installationstandards specified in today's rule asdefined in § 265.192 for tank systems.See § 266.111(e)(4) in today's rulereferencing that section. The standardsinclude: Specifications for assessing thedesign of new direct transfer equipment;backfill requirements for newunderground direct transfer equipment;tightness tests; equipment support andprotection requirements; corrosionprotection; and written certification thatthese requirements have been met.

7. Closure

Today's rule applies by reference theclosure requirements for direct transferequipment provided by § 265.197 (exceptparagraphs (c)(2) through (c)(4)). See§ 266.111(e)(6). That section requires theremoval or decontamination of wasteresidues, system components, andcontaminated soils, structures, andequipment.

XIII. Applicability of the BeviliExclusion to Combustion ResiduesWhen Burning Hazardous Waste

Under the Agency's existingregulations, wastes that are derivedfrom the treatment of listed hazardouswastes are also considered to behazardous unless and until they aredelisted (see 40 CFR 261.3(c)(2) and(d)(2))' The combustion or processing ofhazardous waste in a device that useselevated temperatures as the primarymeans to change the chemical, physical,or biological character or composition ofthe hazardous waste, is a type of -

treatment no matter what type of deviceis used in the process, or for whatpurpose the waste is burned orprocessed. Accordingly, under theAgency's existing rules, residues fromthermal combustion (or processing) oflisted hazardous wastes remain thelisted hazardous wastes until they aredelisted.

When the device burning hazardouswaste is (1) a boiler burning primarilycoal or other fossil fuels, (2) anindustrial furnace processing primarilyores or minerals, or (3) a cement kilnprocessing primarily raw materials, theapplicability of the Bevill exclusion mustbe considered (see RCRA section3001(b)(3)(A)(i-iii)). The Bevill exclusionrefers'to residues resulting from burningor processing certain materials wherebythe residues are not considered to behazardous waste at this time becausethey require special study to determinewhether they should be regulated undersubtitle C.

To determine whether the Bevillexclusion continues to apply when thedevices described above burn or processhazardous waste, today's final rulepromulgates the case-by-casedetermination involving a two-part testas discussed in the October 1989supplement to the proposed rule. See§ 266.112. Under this test, owners andoperators must determine on a site-specific basis whether the co-combustion of hazardous waste hassignificantly affected the character ofthe residue. The residue is considered tobe significantly affected if both: (1)Concentrations of toxic (appendix VIII,part 261) compounds in the waste-derived residue are significantly higherthan in normal (i.e., without burning/processing hazardous waste) residue;and (2) toxic compounds are present inthe waste-derived at levels that couldpose significant risk to human health. Ifthe case-by-case determinationdemonstrates that the residue has beensignificantly affected (or if the owner oroperator does not obtain data andinformation adequate to support ademonstration that the residue has notbeen significantly affected), suchderived-from residues are subject toregulation as hazardous waste becausethe residues are no longer the type ofmaterial Congress commanded theAgency to study before regulation. Suchresidues are no longer deemed to befrom processing ores or minerals,burning fossil fuels, or making cement.Rather, they are from treating hazardouswaste.

The following sections discuss thebasis for applying the Bevill exclusion toderived-from residues, the evolution of




the Agency's interpretations on theapplicability of the Bevill exclusion towaste-derived residues, and howtoday's case-by-case determinationworks.

A. Basis for Applying the BevillExclusion to Derived-From Residues

A number of comments questionedwhether the Agency has the legalauthority to determine that someresidues from coprocessing hazardouswaste with Bevill raw materials couldremain excluded under the Bevillamendment pending completion of thesection 8002 studies. Because theAgency's previous determination of thisquestion (50 FR 49190 (Nov. 29, 1985))could have been more fully explained,the Agency has decided to reopen thequestion in this rule and to respond tothe public comments.

The Agency's consistent position onthis issue is that so long as theprocessing of hazardous waste does notsignificantly affect the character of thewaste residues as high volume/lowhazard, then those wastes can remainexcluded under the Bevill amendment.Put another way, the wastes canpotentially remain the type of materialthat Congress told the Agency to studybefore imposing subtitle C regulation.

Instead of focusing on the question ofwhether coprocessing hazardous wasteaffects the composition of the residuesfrom a Bevill device, some commenterswould have it that the mixture andderived-from rules apply to the residues,so that the residues are subject tosubtitle C (assuming listed wastes arecoprocessed) regardless of the actualeffect of burning hazardous waste. Atthe least, the statute does not compelthis result. In the case of utility boilersburning fossil fuels, the statute statesexplicity that wastes "generatedprimarily from the combustion of coal orother fossil fuels" is to be excluded. Seesection 3001(b)(3)(A)(i). Thus, some typeof co-combustion is expresslyauthorized. With respect to the tworemaining categories of Bevill waste(wastes from processing ores andminerals and cement kiln dust), theBevill amendment (section3001(b)(3)(A)) does not use the term"primarily", but does not expresslyaddress the question of whether theexemption applies when the residuesare produced in part from burninghazardous waste. Thus, read literally,dust from a cement kiln that burnshazardous waste along with normal rawmaterials could be termed "cement kilndust." 84

s EPA does not accept the argument that theomission of the word "primarily" in regard to ore/

If there were doubt on this point, theAgency is convinced that it is dispelledby the 1984 amendments. Sections3004(q)(1) and 3010(a) both stateexplicitly that "(niothing in thissubsection shall be construed to affector impair the provisions of section3001(b)(3)" (the Bevill amendment). Thislanguage would be meaningless unless itallowed some residues from Bevilldevices burning hazardous wastes(specifically hazardous waste fuels) toremain within the scope of the Bevillamendment. Although commentersargued, based on passages from thelegislative history, that the provisionshould not be given this naturalmeaning, the Agency does not find theargument persuasive. Rather, thelegislative history appears to state thatBevill devices burning hazardous wastefuels will be subject to the emissionstandards developed pursuant to section3004(q). See H. Rep. No. 198, 98th Cong.1st Sess. 41; S. Rep. No. 284, 98th Cong.1st Sess. 37. Today's rules accomplishthat result.

At the same time, the Agency isconcerned about reading the Bevillamendment in a manner that gives itundue scope, such as by allowing Bevilldevices to serve as a dumping groundfor other hazardous wastes. We do notview the interpretation adopted todayas allowing the exemption to haveundue scope. In the first place,emissions from the Bevill device itselfare regulated. Second, the facilitybecomes subject to the facility-widecorrective action provisions of sections3008(h) and 3004(u) by virtue ofregulation of the combustion activity.Thus, potential problems relating tomismanagement of waste residues mustbe evaluated and addressed no laterthan during the permitting process.

Most importantly, the Agency believesthat the reading adopted strikes areasonable balance between the termsof the Bevill amendment and otherprovisions and regulations relating tohazardous waste management. Areading that would disqualify residuesfrom the Bevill amendment if anyhazardous waste is burned in the devicewould exalt form over substance bybarring from Bevill eligibility a residuethat was not discernably affected by

mineral processing wastes and cement kiln dustmeans that the residues must come exclusively fromprocessing raw materials exclusively. This type ofnegative inference Is not a compelled reading of thestatute, and the legislative history to the provisionin fact indicates that Congress used the term"primarily" with respect to utility wastes to overrulea 1978 EPA proposed regulation on the scope ofutility wastes, rather than to affect the scope of theremaining two Bevill categories. 126 Cong. Rec. 3383(1980).

burning hazardous waste. Given thatsuch material could be exactly the highvolume/low hazard residue thatCongress told the Agency to studybefore regulating, EPA does not agreewith an interpretation that automaticallyforecloses it from Bevill status. 5 Inaddition, use of Bevill devices forcombusting hazardous wastes providesneeded treatment capacity for a numberof hazardous wastes, and the Agencywould be reluctant to adopt aninterpretation that discouraged safeprocessing of hazardous waste bynecessarily imposing hazardous wastedisposal costs on residues that might notbe affected by the hazardous wastecombustion.

For all of these reasons, therefore, theAgency is reading the statute in a waythat does not automatically disqualifyresidues from coprocessing hazardouswastes in Bevill devices from eligibilityfor Bevill exempt status.

B. Evolution of Interpretations

To determine whether the Bevillexclusion continues to apply when thedevices described above 86 burnhazardous waste fuel, the Agency statedin 1985 (see 50 FR 49190 (Nov. 29, 1985))that the exclusion continues to apply aslong as the hazardous waste is burnedfor energy recovery (i.e., not fordestruction). The underlying principlefor this determination was that whenhazardous waste is used as fuel, thecharacter of the residue would continueto be determined by the Bevill material(e.g., coal, ores or minerals, or cementraw materials) being burned orprocessed. Thus, the residue shouldremain within the Bevill exclusionpending special study before it could beregulated under subtitle C.

In the May 6,1987 proposed rule (52FR 17012-013), the Agency suggestedrefining these determinations to addressresidues from industrial furnacesprocessing ores or minerals and thatalso process hazardous waste formaterials recovery, and residues fromcement kilns that may processhazardous waste as an ingredient.

ss EPA notes that in assessing whether residueshave been affected by hazardous waste burning it isusing a somewhat more rigorous test for assessinginorganic contamination-use of the TCLP ratherthan the synthetic acid rein leaching procedure-than it used in making the high volume/low hazarddetermination for mineral processing wastes. 54 FRat 38630 (Sept. 1. 1989). The Agency views this as anadditional safeguard to assess the possible effectcoprocessing of hazardous waste may have had onthe residues.

86 This is, a boiler burning primarily coal anindustrial furnace processing primarily ores orminerals, or a cement kiln processing primarily rawmaterials.

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Under that proposal, such residueswould remain within the Bevillexclusion provided that at least 50percent of the raw material fed to thedevice consisted of a virgin ore, mineral,or normal raw material. However,residues from devices burninghazardous waste for the purpose ofdestruction (i.e., for neither energy normaterials recovery) would not qualifyfor the Bevill exclusion.

The Agency has evaluated theseinterpretations of the applicability of theBevill exclusion to waste-derivedresidues in light of its stated principlethat residue that results from coburninghazardous waste and Bevill rawmaterials should remain within theBevill exclusion provided that thecharacter of the residue is determinedby the Bevill material (i.e., the residue isnot significantly affected by thehazardous waste). As discussed in theOctober 1989 supplement to theproposed rule (54 FR 43733-36), theAgency does not believe that its database for making these interpretations issufficient to ensure that, in every case,the residue would not be significantlyaffected by the hazardous waste,Further, the Agency has reconsideredwhether the interpretation that residuesgenerated by the subject devices whenburning waste for destruction are notwithin the Bevill amendment isconsistent with the stated principle.Consequently, the Agency proposed inthe supplemental notice to require case-by-case determinations of the effect ofburning hazardous waste on residuals.That case-by-case approach ispromulgated in today's rule.

C. Case-By-Case Determinations

We discuss below which devices areeligible for the Bevil] exclusion ofresidues and how the two-part testworks for determining whethercombustion of the waste hassignificantly affected the residue.

1. Eligible Devices

Until further studies were completed,Congress intended to exclude fromsubtitle C regulation residues from: (1)Devices that burn primarily fossil fuel;(2) industrial furnaces that process oresor minerals; and (3) cement kilns. As theAgency reads these provisions, to beeligible for exclusion from subtitle Cregulation under the Bevill amendment.the waste-derived residue must begenerated from: (1) A boiler burningprimarily coal 87 (2) an industrial

87 The Agency has determined that residues fromcofiring hazardous waste with oil or gas are notexcluded under the Bevill amendment because thecharacter of the residue would be determined by the

furnace processing primarily ores orminerals (otherwise, residues could notbe said to come from processing oresand minerals, but rather from processingother materials), or (3) a cement kilnprocessing primarily raw materials. Toimplement the provision that, to beeligible for the Bevill exclusion thedevice must burn primarily Bevillmaterial, EPA is requiring that a boilermust burn at least 50 percent coal, anindustrial furnace must process at least50 percent ores or minerals, and at least50 percent of the feed stock to a cementkiln must consist of normal rawmaterials. This requirement alsoconfirms the Agency's long-standinginterpretation that the Bevill exclusionapplies only to primary facilities and notto secondary facilities such assecondary smelters.8 8 See § 266.112(a).

2. Two-Part Test

Today's rule requires a case-by-casedetermination as to whether thehazardous waste being burned orprocessed significantly affects thecharacter of the residue with respect toinorganic and organic toxic (i.e.,appendix VIII, part 261) constituents.The residue Is considered to besignificantly affected if both: (1)Concentrations of toxic (Appendix VIII)compounds in the waste-derived residueare significantly higher than in normal(i.e., without burning/processinghazardous waste) residue; and (2) toxiccompounds are present in the waste-derived residue at levels that could posesignificant risk to human health. PartOne of the test need not be conducted ifthe waste-derived residue passes PartTwo of the test (i.e., if the health-basedconcentration limits are not exceeded).Such a waste would still meet the highvolume/low hazard Bevill threshold.

a. Part One-Comparison withNormal Residues. Part One of the testrequires a comparison of hazardouswaste-derived residues with normalresidues to determine if toxiccompounds are present at statisticallysignificant higher levels. See§ 266.112((b)(1). The toxic compounds ofconcern are any compound listed onappendix VIII, part 261, that mayreasonably be expected to be aconstituent in the hazardous waste plusthe list (see appendix VIII to the rule) of

hazardous waste. This is because oil and gas *generally produce little residue when burned and.thus, toxic constituents from the hazardous wastecan significantly affect any residue generated. See50 FR 49190 (Nov. 29, 1985). The Agency is notreopening this determination in today's rule.

q0 In support of this reading, one court has held

that residues from a secondary lead smeler are notcovered by the Bevill amendment. 1kco Co. versusEPA (W.D. Ala. 1986).

organic compounds that are commonproducts of incomplete combustion(PICs) from burning hazardous waste.The total concerntration of eachcompound of concern in the residuesmust be determined8 9 Analyticalprocedures are provided in TestMethods for Evaluating Solid Waste,Physical/Chemical Methods (SW-846)incorporated by reference in § 260.11(a).

The rule requires the use of astatistical test to compare theconcentrations of toxic constituents insamples of normal (without burning/processing hazardous waste) residueswith samples of waste-derived residues.In the statistical test, the 95th percentconfidence interval about the mean ofthe normal residue concentrations (usinga "t" distribution) is used to determinethe upper 95th percent confidenceinterval about the mean. Procedures thatmust be used to determine the upper95th percent confidence interval aboutthe mean are prescribed in "StatisticalMethodology for Bevill ResidueDeterminations" in Methods Manual forCompliance with the BIF Regulation,incorporated in today's rule as appendixIX of part 266. A minimum of tencomposite samples must be obtainedand analyzed to represent the normalresidue in order to effectively calculatethe upper 95th percent confidenceinterval about the mean. This is theconcentration that the waste-derivedresidue may not exceed to pass PartOne of the test. The waste-derivedresidue must be characterized bycomposite samples with a compositeperiod not to exceed 24 hours to ensurethat residues are managed properly andpromptly (i.e., as exempt residues orhazardous waste) and to provide foreffective enforcement. The samplingapproach must be based on (and beconsistent with) representative samplingprotocols described in SW-846 and mustbe documented by recordkeeping.

If operating conditions change so thatconcentrations of toxic compounds Innormal residue may (would have)decrease(d), the owner and operatormust re-establish the "baseline"concentrations in normal residue anduse the lower baseline levels for the test.This is necessary to ensure that owners/operators do not use the mostcontaminated raw materials in order toburn more hazardous waste, and thenswitch back to their normal rawmaterials.

so We note that Part One of the test considers thetotal concentration of each compound, while PartTwo of the test considers, for metals, theconcentration in an extract generated from theToxicity Characteristic Leachate Procedure (TCLP.

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b. Part Two.-Comparison WithHealth-Based Limits. Part Two of thetest requires a comparison of theconcentration of toxic constituents Inthe waste-derived residues with health-based limits the Agency has establishedin appendix VII to the rule. Thecomparison is made to determine iftoxic compounds in the waste-derivedresidue are present at levels higher thanthe health-based limits. The toxiccompounds of concern are the same asfor Part One of the test--any compoundlisted on appendix VIIL part 261, thatmay reasonably be expected to be aconstituent in the hazardous waste plusthe list (see appendix VIII to the rule) oforganic compounds that are commonproducts of incomplete combustion(PICs) from burning hazardous waste.The total concentration of eachnonmetal compound of concern In thewaste-derived residue must becompared with the health-based limit. Inaddition, the concentration of eachmetal of concern in an extract from theToxicity Characteristic LeachingProcedure (TCLP) must not exceed thehealth-based limits.

The Agency does not have adequatehealth effects data (e.g., MCLs, RfDs,unit risk values) to establish health-based limits for many compounds listedin appendix VIIL part 261.Consequently, we have conservativelyestablished a health-based limit for suchcompounds based on the 5th lowestpercentile value of the health-basedvalues for nonmetal compoundsestablished in appendix VII to the rule.That value Is 0.002 ug/kg. This is thesame approach EPA used to establish aRAC for compounds where insufficienthealth effects data were available toestablish a RAC or RsD for thecompound.

The rule requires the use of totalconcentrations of nonmetal compoundsrather than extract concentrations forthe test of health significance because ofburning toxic nonmetal compounds inthese devices should be to destroy thecompounds. (Use of total nonmetalconcentrations thus serves as a partialcheck that combustion is beingconducted properly.) The health-basedlimits for the metals in appendix VII ofthe rule are the Toxicity Characteristic(TC) limits (see j 261.24) for thosemetals for which TC limits have beenestablished. To establish health-basedlimits for the other metals, the Agencyapplied the same 100 fold dilution factorto leachate concentrations used toestablish the TC limits. The Agency hasalso used this same dilution factor inassessing whether mineral processingwastes satisfy the low hazard prong of

the Bevill test. See 54 FR 36630 (Sept 1,1989).

To determine if the concentrations oftoxic compounds in the waste-derivedresidues are higher than the health-based limits, owners and operators mustobtain and analyze composite samplesof waste-derived residues with acomposite period not to exceed 24 hours.The sampling approach must be basedon (and be consistent with)representative sampling protocolsdescribed in SW-846 and must bedocumented by recordkecping.

D. RecordkeepingOwners and operators must maintain

for a period of three years records ofsampling and analyses of residues tosupport claims that the waste-derivedresidue retains the Bevill exclusion.

E. Other Considerations

1. Generic DeterminationsIn the October 26, 1989 supplement to

the proposed rule, the Agency requesteddata and information that it could use tosupport: (1) Generic determinations oflevels of toxic constituents in normal(i.e., generated without burning/processing hazardous waste) residues;and (2) generic determinations thatcertain waste-derived residues are notsignificantly affected by burning/processing hazardous waste, and, thus,remain excluded without the need tomake the case-by-case demonstration.

a. Normal Residues. After review ofcomments on the 1989 supplementalnotice, the Agency concluded that it isnot practicable to establish genericconcentrations of toxic constituents innormal residues. Commenters noted thatthere were so many site-specificvariables that affect the concentration oftoxic constituents in normal residuesthat this approach was not workable.Variables include the type of industrialfurnace, type of fuels burned, and typeand source of raw materials used byindustrial furnaces. The Agency initiallyconsidered establishing genericconcentration levels in normal residuesto avoid giving an advantage to facilitiesthat use fuels or raw materials with high(i.e., higher than normal for the industry)levels of toxic constituents. Normalresidues from such facilities would havehigh levels of toxic constituents. Thus,waste-derived residues from suchfacilities could also have high levels oftoxic constituents. Consequently, suchfacilities could burn/process hazardouswaste with high levels of toxicconstituents without losing the Bevillexclusion of residues. We note thatenforcement officials will give priorityconsideration to those facilities whose

residues fail part 2 (health-based limits)of the test to determine Bevillapplicability and rely on part 1(comparison with normal residues) toretain the exclusion. Owners andoperators must be able to support, atany time, that the nonhazardous wastefeedstreams being fed into the devicewhen hazardous waste is fired are thesame (or would not decrease theconcentrations of toxic constituents inresidues as those fired when theconcentrations of toxic constituents innormal residues were determined. If theconcentrations of toxic constituents innonhazardous feedstreams decreasesignificantly from those concentrationswhen the normal residue was generatedfor purposes of establishing normalconcentrations of toxic constituents (orif design or operating conditions changesuch that levels of toxic constituents Innormal residue could decreasesignificantly), then the owner/operatormust establish new, lower,concentrations for normal residue.

b. Excluded Residues. The Agencyalso concluded that it is not practicableto make generic determinations thatcertain waste-derived residues are notsignificantly affected by burning orprocessing of hazardous waste and, so,remain excluded. This approach is notworkable given that the exclusion wouldhave to be conditioned on a number offactors including: (1) The composition,feed rate, and method of feeding theharzardous waste; (2) the type of device;(3) the composition, feed rate, andmethod of feeding any other fuels; and(3) the composition, feed rate, andmethod of feeding any raw materials.The data base to support suchdetermination is not available.Moreover, any such generic exclusionthat is necessarily conditioned on somany factors would be of little practicaluse to the regulated community giventhe variability of normal operations.

2. Burning for Destruction

The case-by-case approach todetermine the effect of coburning onresidues from Bevill devices focuses onthe residues that are actually generatedrather than on the purpose for which thehazardous waste is burned. Thus,residues generated from burninghazardous waste in boilers andIndustrial furnances for the purpose ofdestruction 90 are eligible to retain the

90 For example, wastes with low heating valuethat are not burned for materials recovery or as aningredient are burned for destruction. We note thatsuch wastes may be burned only by new facilitiesas Incinerators under an operating permit or bythose existing facilities operating under Interimstatus that also have certified compliance with theapplicable emissions standards.

7199



7200 Federal Register I Vol. 56, No. 35 / Thursday, February 21, 1991 I Rules and RegulationsBevill exclusion. The Agency's historicapproach to the issue of cogeneratedresidues has been to focus on thecharacter of the residues to ascertainwhat determines their character--theBevill material or the hazardous wastebeing burned/processed (see 50 FR49190 (November 29, 1987)). The statuteitself does not directly specify that thepurpose of the burning is a relevantcriterion, but instead states that certaintypes of waste are excluded fromsubtitle C regulation pending completionof required special studies. Since theBevill devices would still be engaged inthe Bevill activity, and composition ofthe residues would potentially beunaffected, the Agency sees no absolutebar to allowing Bevill status for suchresidues.Part Four Miscellaneous ProvisionsI. Regulation of Carbon RegenerationUnits

A. Basis for Regulating CarbonRegenerating Units as ThermalTreatment Units

In today's rule, EPA is clarifying theregulatory status of carbonregeneration 91 units. Since 1980,controlled flame (direct flame) carbonregeneration units which destroyorganic contaminants adsorbed ontoactivated carbon have met the definitionof incinerator and were subject toregulation as such, while carbonregeneration nonflame thermal unitswere treated as exempt reclamationunits. Today's rule defines carbonregeneration unit and incinerator (see§ 260.10) to ensure that both direct flameand nonflame thermal carbonregeneration units are regulated asthermal treatment units under theinterim status standards of part 265,subpart P, and the permit standards ofpart 264, subpart X.

One commenter expressed concernthat the thermal treatment standards ofsubpart X were vague. EPA disagreesand points out that subpart X, part 264covers miscellaneous hazardous wastemanagement units that do not or maynot fit the description of any of the unitscovered by other part 264 regulations.Without subpart X. these unregulatedunits could only operate as interimstatus facilities and could not be fullypermitted, thereby preventing theconstruction of new units or someexpansions of existing units. EPArecognized that some types of new unitsthat were not previously allowed to beconstructed could reduce risks to humanhealth and the environment from the

91 The term "regeneration" includes reactivationof used carbon for reuse.

management of hazardous waste.Promulgation of subpart X genericpermitting standards was intended toallow such construction and flexibilityfor technical development andinnovation and to cover diversetechnologies and units. The subpart Xstandards specify that health andenvironmental safety must be a primaryconcern during the management ofhazardous wastes in miscellaneousunits. If the need arises, the Agency maydevelop specific technology standards inthe future (see 52 FR 46964, December10, 1987]. Although several commenterssupported the application of part 264,subpart 0 incinerator standards todirect flame and nonflame devices, EPAhas decided against this sincedemonstration of conformance with theDRE standards (and the proposed CO/THC standards) may not be achievableor warranted for carbon regenerationunits considering the relatively lowlevels of toxic organic compoundsadsorbed onto the activated carbon.

B. Definition of Carbon RegenerationUnit and Revised Definition ofIncinerator

Several commenters requested thatEPA consider revising the definition of acarbon regeneration unit so that certainunits used for air emissions control, wetoxidation, and general recycling, wouldnot be regulated. Activated carbon unitsused as air emission control devices ofgaseous industrial process emissionswill not necessarily be regulatedbecause trapped organics in suchcolumns are not hazardous wastesbecause the gas originally being treatedis not a solid waste (it is an uncontainedgas 92), and therefore any condensedorganics do not derive from treatment ofa hazardous waste. (The nongasresidues from these devices could behazardous wastes if they are listed or ifthey exhibit a characteristic, however.)However, regeneration or reactivation ofcarbon used to control air emissionsfrom hazardous waste treatment,storage, or disposal facilities (e.g., under40 CFR parts 264 and 265, subpart AA,June 21, 1990, 55 FR 25454) is subject toregulations as a RCRA thermaltreatment unit.

We considered whether other unitstruly are engaged in reclamation, orwhether the regeneration of the carbonis just the concluding aspect of thewaste treatment process thatcommenced with the use of activatedcarbon to adsorb waste contaminants,which are now destroyed in the,.regeneration" process (just as rinsing

99 See 47 FR at 27530 (June 30,1982) and 54 FR at50973 (Dec. 11, 1989).

out a container of hazardous waste is astage in the storage process and doesnot constitute recycling of thecontainer). Irrespective of whether theseunits are better classified as wastetreatment or recycling units (or whetherthe units are flame or nonflame devices),we are concerned, as indicated above,that emissions from the regenerationprocess can pose a serious hazard topublic health if not properly controlled,and therefore are clarifying today thatthey are regulated as thermal treatmentunits.

We note that this revision also appliesto those carbon regeneration units that,while in active service treatingwastewater, meet the definition ofwastewater treatment units in § 260.10.Such units are exempt from RCRApermitting standards while treatingwastewater. However, these units arenot exempt from RCRA regulation whenthey are being regenerated because theyare not treating wastewater during theregeneration process. Rather, theactivated carbon columns themselvesare being treated thermally. The thermalregeneration unit is subject to part 265,subpart P (existing units) or part 264,subpart X (new units).C. Units in Existence on the EffectiveDate of the Rule are Eligible for InterimStatus

Although certain carbon regenerationunits may technically have met eitherthe 1980 or 1985 definitions ofincinerator, the Agency believes thatthere has been legitimate doubt as tothese units' regulatory status (which iswhy the Agency undertook thisrulemaking to clarify the status). Theunits might potentially have beenclassified as incinerators, thermaltreatment units, or perhaps exemptrecycling units. It would also have beenconfusing to interpret the rules in amanner that carbon regeneration unitswere not all regulated in the same way,given that their functions and activitiesare roughly identical whether or not theunits are direct-fired. In fact, the mostnatural classification of these units, andthe one the Agency intended, is asthermal treatment units. (EPA does notbelieve that these are recycling units,but rather that regeneration is acontinuation of the waste treatmentprocess, that process consisting ofremoval of pollutants by adsorptionfollowed by their destruction. Nor doesthe Agency believe that incineratorstandards make technical sense forthese devices, as noted above). Inaddition, few if any of these units haveactually been regulated as incineratorsin practice.

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For these reasons, EPA is findingpursuant to § 270.10(e)(2) that there wassubstantial confusion as to whichowners or operators of carbonregeneration units were required tosubmit a part A application and that thisconfusion is attributable to ambiguitiesin the subtitle C rules. Accordingly, suchowners and operators may submit partA applications by the effective date oftoday's regulations and be eligible forinterim status under part 265, subpart P(assuming they meet remainingrequirements for interim statuseligibility, and the facility is not alreadysubject to interim status for other units).

11. Sludge Dryers

In today's rule, the Agency isclarifying the regulatory status of sludgedryers. In particular, the rule adds adefinition of "sludge dryer" to § 260.10and amends the definition of"incinerator" in § 260.10 to specificallyexclude sludge dryers.

On November 17, 1980 (45 FR 76074).EPA suspended the applicability of theRCRA permitting requirements (40 CFRpart 122, which is now codified as part270) and hazardous waste managementfacility standards (40 CFR parts 264 and265) to owners and operators of devicesmeeting the definition of "wastewatertreatment unit" in 40 CFR 260.10 and270.2.

Since promulgation of this wastewatertreatment unit exclusion from RCRApermitting requirements, the Agency hasreceived numerous requests todetermine if certain types of unitssatisfy the definition of "wastewatertreatment unit" and, therefore, wouldnot require a RCRA permit. Many ofthese requests have concerned theregulatory status of thermal treatmentunits, particularly sludge dryers.Commenters have also requestedclarification of the regulatory status ofsludges from thermal treatment units.Most of the requests have been fromowners and manufacturers of sludgedryers. The Agency believes thatapproximately 40 sludge dryers arecurrently being used in the metalfinishing industry to dehydrate metalhydroxide sludges (EPA HazardousWaste F006) generated in the treatmentof wastewater.

In response to these inquiries, EPAdistributed policy memoranda to theRegional offices explaining that a sludgedryer is included within the scope of thewastewater treatment tank exclusion,provided that it meets the definition of"wastewater treatment unit." (SeeOSWER Policy Directives 9503.52-1Aand 9503.51-lA, available upon requestfrom the RCRA Hotline.) In addition,with respect to the status of the sludges

themselves, they are hazardous waste ifidentified or listed (including byapplication of the mixture and derived-from rules) and are subject to regulationwhen removed from the tanks.

Despite the original November 17.1980 preamble discussion and the policyclarification, the regulatory status ofsludge dryers has continued to beunclear. One reason for the confusion isbecause it is not clear whether a sludgedryer satisfies the third component ofthe definition of wastewater treatmentunit (i.e., whether it meets the definitionof a "tank" or "tank system"). TheAgency has determined that sludgedryers that are integrally equipped withfeed or discharge hoppers that providefor an accumulation of waste satisfy thedefinition of "tank system." 93 Based oninformation available to EPA at thistime, it appears that most sludge dryersare so equipped. (Those sludge dryersthat are not so designed may still beconsidered tanks, but a case-by-casedecision must be made.) The Agencyhas also determined that other types ofequipment not obviously meeting the"tank" definition, such as presses,filters, sumps, and other types ofprocessing equipment, are coveredwithin the meaning of the term "tank" or"tank system" when used in the contextof this exclusion (see OSWER PolicyDirective 9503.52-1A).

Another reason that the regulatorystatus of sludge dryers has been thesubject of many questions may bebecause some sludge dryers techmicallymeet the current definition of an"incinerator," although EPA neverintended to regulate direct-flame (ornonflame) sludge dryers as incinerators.When EPA amended the definition of"incinerator" to use physical designcriteria rather than a primary purposetest (i.e., purpose of burning) to definean incinerator, it did not intend to bringsludge dryers under regulatory controlas incinerators. (See 50 FR 625, January4, 1985, indicating that the reviseddefinition would not bring largenumbers of devices other thanincinerators under incineratorstandards.) Under the former primarypurpose definition, sludge dryers werenot incinerators. Although under the1985 revised definition of incineratorsludge dryers could be classified asincinerators, this was not EPA'sintention. The Agency is clarifying thisambiguity by clearly regulating all

93 We note that sludge dryers that are a part of awastewater treatment facility that is subject toregulation under either section 402 or 307(b) of theClean Water Act and that do not meet the definitionof a tank system are subject to RCRA regulation asthermal treatment units, just like sludge dryers thatare not a part of a wastewater treatment system.

nonexempt sludge dryers (i.e., those notmeeting the definition of "wastewatertreatment unit" under today's rule, asdiscussed below) under the interimstatus standards of part 265, subpart P("Thermal Treatment"), and the permitstandards of part 264, subpart X("Miscellaneous Units"). See 55 FR17866 (April 27, 1990) for details. Giventhat such units managing hazardouswaste always were subject to some typeof regulation, they are not newly eligiblpfor interim status as a result of today'sclarification.

Even though as a result of thisamendment sludge dryers arepotentially subject to regulation undersubpart P of part 265 and subpart X ofpart 264 as other thermal treatmentunits, sludge dryers that meet the§ 260.10 definitions of "wastewatertreatment unit" and "tank" or "tanksystem" continue to be exemptwastewater treatment units under9 § 264.1(g)(6) and 265.1(c)(10). TheAgency believes that virtually all sludgedryers meet the tank/tank systemdefinition and, therefore, would beexempt when used as part of awastewater treatment system.

A. July 1990 Proposal

To better clarify the regulatory statusof sludge dryers, the Agency proposedon July 18, 1990 (55 FR 29280) adefinition for "sludge dryer" to clearlydistinguish them from other thermaltreatment units: Sludge dryer means anyenclosed thermal treatment device thatis used to dehydrate sludge and that hasa maximum total thermal input of 1,500Btu/lb of sludge treated on a wet-weightbasis.

In the same notice, the Agency alsoproposed to amend the definition of awabtewater treatment unit to say thatsludge dryers were the only thermaltreatment devices (heretofore) meetingthe definition of a wastewater treatmentunit that were exempt from regulation.

Today's rule clarifies that sludgedryers meeting the definition of awastewater treatment unit are exemptfrom regulation (by promulgating adefinition of sludge dryer and revisingthe definition of incinerator to excludesludge dryers). EPA also proposed afurther clarification that other devicesthat use heat to treat wastewaters werenot to be considered eligible for thewastewater treatment tank exemption.The Agency indicated, withoutdiscussion, that it had not intended forsuch units to be eligible for theexemption and that the proposal was asimple clarification which reflectedcommon understanding within theAgency and the regulated community.

7201




Commenters disagreed with thisassessment of the regulations, and theAgency has since studied the issue inmore depth. It appears that the Agencywas mistaken in its assessment both ofthe current intended scope of the ruleand of common understanding of whatthe rule covers. With respect to suchdevices as evaporators and steamstrippers used in wastewater treatment,the Agency has in fact traditionallyregarded such units as eligible for thewastewater treatment exemption. See 55FR at 25467 (June 21,1990). Commenterslikewise indicated their understandingthat current rules exempt such devices.

Given the narrow scope of theproposal, the clear indication that anychange would not be a clarification ofexisting rules (as indicated) but rather apotentially far-reaching alteration, andthe absence of any discussion (or study)of whether a substantive change inregulatory status of these devices iswarranted, EPA cannot go forward.Consequently, we are not adopting anyother part of the definition ofwastewater treatment unit discussed inthe 1990 notice.

B. Summary of Public CommentsEPA received comments regarding the

status of sludge dryers in response tothe April 27, 1990 BIF notice and the July18, 1990 notice discussed above.

Many of the commenters to thesenotices supported the inclusion of sludgedryers in the wastewater treatment unit(WWTU) definition. The commenters,however, requested clarification onwhether units similar to sludge dryers(e.g., evaporators] would also be eligiblefor the WWTU exclusion. As discussedabove, other devices using heat thatmeet the definition of wastewatertreatment unit would continue to beexempt from RCRA regulation (except,of course, an incinerator, boiler, orindustrial furnace burning hazardouswaste.

Eleven commenters to these proposalsstated that the maximum 1,500 Btu/Ibthermal input requirement in the sludgedryer definition is too low. Citing lowthermal efficiencies (especially forindirect-fired dryers), these commentersrecommended thermal inputrequirements ranging from 1,700 to 3,300Btu/Ib.

After consideration of thecommenters' concerns and furtherreview of the technical backgroundinformation on the thermal input limit,the Agency is today revising the thermalinput limit to 2,500 Btu/Ib wet sludge.The Agency believes that depending onthe nature of the treatment system, thethermal input to a bona fide sludgedryer (i.e., a device that is not an

incinerator) can be as high as 2,500 Btu/lb.

Several commenters also requestedthat EPA clarify that the total thermalinput limit was not to include theheating value of the sludge itself giventhat a number of sludges that are driedhave as-fired heating values of 1,000 to2,700 Btu/lb. The Agency agrees. Thefinal rule explicitly excludes the heatingvalue of the sludge from the 2,500 Btu/Iblimit on thermal input. With thisclarification, however, we note that theprimary purpose test-dehydration-isthe primary distinction between asludge dryer and an incinerator. This isbecause a sludge incinerator can readilymeet the thermal heat input limit of 2,500Btu/Ib when the heating value of thesludge itself is not included. However,the primary purpose of a sludge dryer isdehydration while the primary purposeof an incinerator is volume reduction toproduce an ash residue. Thus, webelieve that the definition in today's ruleadequately distinguishes betweensludge dryers and incinerators.Nevertheless, it should be noted thatany person claiming the wastewatertreatment unit exemption for a sludgedryer must have documentation tosupport that the primary purpose of thedevice is to dehydrate sludge, not todestroy sludge to produce an ashresidue.

The Agency received many responsesto its request for comments on whetherit is necessary to specify a minimumpercent volume reduction in thedefinition of a sludge dryer. Althoughone commenter stated that a percentvolume reduction should be specified inthe sludge dryer definition, twelve of thecommenters stated that such arequirement would be arbitrary,confusing, unworkable, and costly toenforce. Two of the commenters statedthat a minimum percent weightreduction would be more appropriate. Intoday's rule, the Agency has decided notto specify a minimum percent volume(or weight) reduction in the definition ofa sludge dryer. The Agency believes thatsuch a specification would be difficult tosupport and would not be needed todistinguish sludge dryers fromincinerators.

Several commenters stated that theAgency should address emissions ofvolatile organics from units such assludge dryers. In addition, twocommenters recommend a 1,000 Btu/Ibthermal input limit for the device tocontrol volatile emissions from sludgedryers. EPA recognizes the need toaddress volatile emissions from sludgedryers and intends to evaluatealternatives for regulating these units ata later date. However, because this rule

simply clarifies that EPA intended forsludge dryers that meet the definition ofa wastewater treatment unit to beexempt from the RCRA rules, it wouldbe inappropriate to address volatileorganic emissions at this time.Nonetheless, sludge dryers that do notmeet the definition of a wastewatertreatment unit (e.g., sludge dryers thatare not a part of a wastewater treatmentfacility that is subject to regulationunder either section 402 or 307(b) of theClean Water Act) are subject toregulation as thermal treatment unitsunder subpart X of part 264. Under thosestandards, the Agency may applycontrols on volatile organic (and other)emissions as necessary to protecthuman health and the environment.

After considering comments on theproposed sludge dryer definition, EPA istoday promulgating the followingdefinitions:

Sludge dryer means any enclosedthermal treatment device that is used todehydrate sludge and that has amaximum total thermal input, excludingthe heating value of the sludge itself, of2,500 Btu/Ib of sludge treated on a wet-weight basis. -

Incinerator means any encloseddevice that: (1) uses controlled flamecombustion and neither meets thecriteria for classification as a boiler,carbon regeneration unit, or a sludgedryer, nor is listed as an industrialfurnace; or (2) meets the definition ofinfrared incinerator or plasma arcincinerator.

III. Classification of Coke and By-Product Coal Tar

A. AISI Petition

The American Iron and Steel Institute(AISI) petitioned EPA with respect tothe practice of recycling tar decantersludge by the following means:

1. Applying the sludge to coal prior toor just after charging the coal into thecoke oven; and

2. Combining the sludge with coal tarprior to its being sold.

The coke and the coal tar are oftenused as fuel and so have been classifiedas solid wastes and hazardous wastessince they are fuels produced orotherwise containing a hazardouswaste-EPA Hazardous Waste No.K087, tar decanter sludge. See§ 261.2(c}(2)(i(B). These hazardouswaste fuels have been exempt fromregulation under § 261.6(a](3)(vii) and 50FR 49170-171 (November 29, 1985). TheAISI has requested that EPA not classifysuch coke or coal tar as solid wastes.AISI submits that recycling the decantersludge in this manner does not




significantly affect the concentration oftoxic metal and organic constituents ofthe coke or coal tar. EPA has indicatedthat waste-derived fuels could beclassified as products under suchcircumstances, "since the more waste-derived fuels from a process are likeproducts from the same processproduced by virgin materials, the lesslikely EPA is to classify the waste-derived fuel as a waste." 50 FR 49169(Nov. 29, 1985). To support its request,the AISI submitted data on the metalsand organic constituents in coke, coaltar, and tar decanter sludge both withand without sludge recycling, the dataand the Agency's response arediscussed below.

B. Process Description

Coke used for making iron ismanufactured through the destructivedistillation of coal in ovens. A typicaloven holds aproximately 13 tons of coalwhich is heated to a temperature ofabout 2000°F. Generally 20 to 100 ovensare located adjacent to each other in a"coke oven battery." The destructivedistillation or "coking" process takesabout 15-18 hours. During that timeperiod, about 20-35 percent of the coal isconverted to coke oven gas (COG)consisting of water vapor, tar, light oils,heavy hydrocarbons, and other chemicalcompounds. The COG is collected fromthe top of the coke oven and, in mostcases, sent to the by-product plant viathe coke battery main. The COG is thencleaned by removing wastes and by-products prior to being burned, generallyin the coke oven under-firing system. Asa first step in the COG cleaning process,the coal tars, consisting of heavyhydrocarbons, are condensed from thegas. In addition, most of the particulatethat escapes from the ovens is collectedin the tar. This particulate is believed toconsist principally of coal fines. Theparticulate or solids are then removedfrom the tar in the tar decanter. The coaltar is then burned as fuel or sold for usein various products such as roofingcement. The sludge has been listed asEPA Hazardous Waste No. K087 and isdisposed of or recycled either by mixingwith coal prior to being charged to thecoke oven or mixing with coal tar afterphysical processing (grinding) prior tosale.

Approximately 8-12 gallons of tar areproduced per ton of coke. In addition,approximately one pound of tardecanter sludge is produced for every 40pounds of tar produced.

C. Basis for Approval of the AISIPetition

The AISI submitted data from metaland organic chemical analyses for the

coke, coal tar, and tar decanter sludgefrom four plants. The Agency reviewedthese results and determined thefollowing:

1. The recycling of tar decanter sludgeby application to the coal charge doesnot appear to have a significant effecton the chemical composition of coke;

2. The organic chemical compositionof the tar decanter sludge does notappear to be significantly different fromthe coal tar; and,

3. The concentration of one metal,lead, in the sludge appears to be slightlyhigher than in the coal tar. However, theincrease does not appear to bestatistically significant due to the highvariability of the concentration values.

Based on the above and the fact thatthere is such a small quantity of sludgerelative to the quantity of coke and coaltar produced by the coking process, EPAbelieves that sludge recycling, asdescribed here, does not significantlyaffect the concentration of toxic metalsand organic constituents in coal tar orcoke. Furthermore, coke, coal tar, andthe decanter tank tar sludge are similarmaterials formed in a single process andcontain the same contaminants. In thiscircumstance, when the coke and thedecanter tank tar sludge are very nearlythe identical substance and, moreover,come from a single process, the Agencyis warranted in exercising its discretionto determine that this management ofthe sludge is "not part of the wastediposal problem", and hence that thecoke product is no longer a RCRA solidwaste. American Mining Congress v.EPA, 907 F. 2d 1179, 1186 (D.C. Cir. 1990).Therefore, in today's rule, EPA isclassifying such coke and coal tar asproducts, not wastes. As a result, thecoke and coal tar will be excluded under40 CFR 261.4 from the definition of solidwaste and not subject to RCRAhazardous waste managementregulations, when used as a fuel. Anecessary corollary to this action is alsoto exclude the coking process fromregulation when K087 is used as aningredient to produce coke. Given thatK087 is for practical purposes just likeother materials used to produce cokeand comes the the same process asthese other materials, it would beanomalous to assert RCRA control overthe coking process. Again, this form ofsludge management-which is the sameas raw material management-does notappear to EPA to be part of the wastedisposal problem. 4 (In addition, coke

"4The Agency Is not aware of any otherhazardous wastes that are burned in coke ovens asan ingredient that are just like other materials usedto produce coke. If such materials are used, theAgency would encourage the industry to provide the

ovens are subject to a special regulatoryregime under amended section 112(i)(8)of the Clean Air Act, and RCRAregulation of this particular practicecould disrupt the Clean Air Actregulatory scheme. Thus, the Agencyviews RCRA regulation of this practiceas inappropriate in any case.)

This exemption applies only to thewaste-derived fuels and only whenderived from tar decanter sludge, K087.Thus the tar decanter sludge, K087, issubject to full RCRA regulation prior torecycling. In addition, the exemptiondoes not extend to coke or coal tarproduced from hazardous waste (e.g.,spent solvents) other than tar decantersludge, EPA Hazardous Waste K087.IV. Regulation of Landfill Gas

In the November 29, 1985 final rulesregulating hazardous waste burned forenergy recovery, the Agency indicatedthat gas recovered from hazardouswaste landfills that is burned for energyrecovery in boilers or industrial furnacesis not regulated under the waste-as-fuelrules. 50 FR 49171. EPA took this actionin order to study further the extent towhich there might be jurisdictionallimits on the Agency's authority undersection 3004(n) of RCRA to regulategaseous emissions from hazardouswaste. Id. In today's rule, we areamending this language slightly byindicating that the exemption alsoapplies to gas recovered from solidwaste landfills. Therefore, gas recoveredfrom a solid waste landfill that exhibitsa hazardous characteristic would alsobe exempt from today's rule whenburned for energy recovery in a boilerand industrial furnace.

In addition, the Agency solicitedcomment, in the May 6,1987 proposedrule, on whether the hydrocarbon phaseof the condensate removed fromrecovered gas should also be exemptfrom regulation when burned as fuel (52FR 17021). Two commenters respondedthat the condensate contains chemicalconstituents similar to fossil fuels suchas kerosene or gasoline and that thehandling and burning of the gascondensate poses no significant hazardto human health. The commentersencouraged the Ageny not to regulatethe hydrocarbon phase of the landfillgas condensate unless the hydrocarbonsexhibit a subtitle C characteristic of ahazardous waste. However, data oncondensate composition provided byone respondent was vague andrepresented only one source ofcondensate. Absent adequate data EPA

necessary information In order to determinewhether the exclusion should be modified.

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is not promulgating an exemption fromregulation of the hydrocarbon phase ofthe landfill gas condensate at this time.Facilities that wish to burn a landfill gascondensate may consider whether theyare eligible for the small quantity burnerexemption promulgated in this rule.V. Definitions of Infrared and PlasmaArc Incinerators

Today's rule establishes definitionsfor infrared and plasma arc incineratorsand revises the definition of incineratorto explicitly include these devices. Asdiscussed in the April 27, 1990 proposedamendments to the incineratorstandards (55 FR at 17869-70), EPA isclarifying that these devices areincinerators rather than (other) thermaltreatment units subject to regulationunder subpart X of part 264 (or subpart Pof part 265 for interim status units)because: (1) although these devices usenonflame sources of thermal energy totreat waste in the primary chamber, theyinvariably employ controlled flameafterburners to combust hydrocarbonsdriven off by the primary process (and,thus, they meet the definition of an"incinerator" under § 260.10); and (2) theincinerator standards are workable andprotective for these units.

We note that today's action merelyclarifies the regulatory status of thesedevices. It does not subject them toregulation for the first time; they havebeen regulated since 1980. Thus, interimstatus is not reopened for these devices.Part Five: Administrative, Economic, andEnvironmental Impacts, and Ust ofSubjects1. State Authority

A. Applicability of Rules in AuthorizedStates

Under section 3006 of RCRA, EPAmay authorize qualified States toadminister and enforce the RCRAprogram within the State. (See 40 CFRpart 271 for the standards andrequirements for authorization.)Following authorization, EPA retainsenforcement authority under sections3008, 7003 and 3013 of RCRA, althoughauthorized States have primaryenforcement responsibility.

Prior to the Hazardous and SolidWaste Amendments of 1984 (HSWA), aState with final authorizationadministered its hazardous wasteprogram entirely in lieu of EPAadministering the Federal program inthat State. The Federal requirements nolonger applied in the authorized State,and EPA could not issue permits for anyfacilities in the State which the Statewas authorized to permit. When new,more stringent Federal requirements

were promulgated or enacted, the Statewas obliged to enact equivalentauthority within specified time frames.New Federal requirements did not takeeffect in an authorized State until theState adopted the requirements as Statelaw.

In contrast, under section 3006(g) ofRCRA, 42 U.S.C. 6926(g), newrequirements and prohibitions imposedby HSWA take effect in authorizedStates at the same time that they takeeffect in nonauthorized States. EPA isdirected to carry out those requirementsand prohibitions in authorized States.including the issuance of permits, untilthe State is granted authorization to doso. While States must still adoptHSWA-related provisions as State lawto achieve or retain final authorization,the HSWA applies in authorized Statesin the interim.

The majority of today's rule ispromulgated pursuant to section 3004(q)of RCRA, a provision added by HSWA.(The provisions that are notpromulgated pursuant to HSWA are theprovisions for sludge dryers, carbonregeneration units, infrared incinerators,and plasma arc incinerators.)Therefore,the Agency Is adding the requirements(except the non-HSWA provisions) toTable I in § 271.1(j) which identifies theFederal program requirements that arepromulgated pursuant to HSWA andthat take effect in all States, regardlessof their authorization status. States mayapply for either interim or finalauthorization for the HSWA provisionsidentified in Table 1, as discussed in thefollowing section of this preamble.B. Effect on State Authorizations

As noted above, EPA will implementthe majority of the provisions of today'srule in authorized States until theymodify their programs to adopt theserules and the modification is approvedby EPA. Because these provisions of therules are promulgated pursuant toHSWA, a State submitting a programmodification may apply to receive eitherinterim or final authorization undersection 3006(g)(2) or 3006(b),respectively, for these provisions on thebasis of requirements that aresubstantially equivalent or equivalent toEPA's. The procedures and schedule forState program modifications for eitherinterim or final authorization aredescribed in 40 CFR 271.21. It should benoted that all HSWA interimauthorizations will expire January 1,1993. (See § 271.24(c).)

The provisions of today's rule that arenot promulgated pursuant to HSWA-provisions for sludge dryers, carbonregeneration units, infrared incinerators,and plasma are incinerators--are not

effective in authorized States. Thus,these requirements will be applicableonly in those States that do not havefinal authorization. In authorized States,the requirements will not be applicableuntil the State revises its program toadopt equivalent requirements underState law.

40 CFR 271.21(e)(2) requires thatStates that have final authorization mustmodify their programs to reflect Federalprogram changes, and mustsubsequently submit the modificationsto EPA for approval. The deadline bywhich the State must modify its programto adopt the HSWA portion of today'srule is July 1, 1993 if a statutory changeis not needed, or July 1, 1994 if astatutory change is needed. Thedeadline by which the State mustmodify its program to adopt the non-HSWA portion of today's rule is July 1,1992 if a statutory change in not needed,or July 1, 1993 if a statutory change isneeded. These deadlines can beextended in certain cases (40 CFR271.21(e)(3)). Once EPA approves themodification, the State requirementsbecome Subtitle C RCRA requirements.

States with authorized RCRAprograms may already haverequirements similar to those in today'srule. These State regulations have notbeen assessed against the Federalregulations being promulgated today todetermine whether they meet the testsfor authorization. Thus, a State is notauthorized to implement theserequirements in lieu of EPA until theState program modification is approved.Of course, States with existingstandards may continue to administerand enforce their standards as a matterof State law.

In implementing the Federal programfor the HSWA portion of today's rule,EPA will work with States undercooperative agreements to minimizeduplication of efforts. In many cases,EPA will be able to defer to the States intheir efforts to implement theirprograms, rather than take separateactions under Federal authority.

States that submit their officialapplications for final authorization lessthan 12 months after the effective dateof these standards are not required toinclude standards equivalent to thesestandards in their application. However,the State must modify its program by thedeadlines set forth in § 271.21(e). Statesthat submit official applications for finalauthorization 12 months after theeffective date of these standards mustinclude standards equivalent to thesestandards in their application. 40 CFR271.3 sets forth the requirements a State




must meet when submitting its fimalauthorization application.

IL Regulatory Impacts

A. Cost Analysis

1. Background

Prior to publication of the proposedregulations in May 1987, the Agencyexamined the projected compliancecosts, economic impacts, and riskreductions associated with the proposedrules. This effort consisted of a detailedexamination of the pre-proposal draft asIt was drafted in mid-1986 and asupplement prepared in late 1986 95 thatexamined several changes in tax policyand regulatory approach that occurredafter the first analysis was completed.96

The analyses estimated that of theapproximately 1,000 BIFs identified asfiring hazardous wastes, approximately20 percent were likely to discontinueburning hazardous wastes because ofthe rules, 60 percent would burn smallamounts of waste and would qualify forthe small quantity burner exemption(SQBE), and the remaining 15 percentwould obtain full permits. Because thefinal 15 percent of devices representlarge facilities, however, the impact onthe total quantity of waste burnedwould be small. For example, under the"base case" scenario, although 20percent of the devices woulddiscontinue burning hazardous wastesand a number of other devices wouldreduce the quantity of hazardous wastethey combust in order to qualify for theSQBE, only 3 percent of the quantity ofwaste combusted in the absence ofregulations would be diverted to otherdevices. The mid-1986 analysisestimated that under this scenario, theaggregate after-tax cost of compliance toindividual firms would be $5.2 millionper year and that the before-tax socialcost would be $8.2 million per year.Under other sets of assumptions (i.e.,other scenarios), these costs were likelyto be higher, but in all cases wereestimated to be less than $100 millionper year.

Based on these analyses, the Agencyconcluded that the total social costs,impact on market, competition, and theimpact on small businesses were suchthat the proposed regulations did notconstitute a major rule, and that aformal Regulatory Impact Analysis asdescribed in Executive Order 12291 wasnot required.

" U.. EPA, "Regulatory Analysis for Waste-As-Fuel Technical Standards", Draft Report, Octobert9eS.

0 U.S. EPA. "Effects of Recent Changes on theEstimated Costs and Benefits of the ProposedWasWe As Feel Technical Standards", January 1987.

A number of comments on theeconomic analysis were received fromaffected businesses and other groups.Most of these commenters contendedthat the cost of compliance had beenunderestimated by the Agency. Basedon these comments, as well as changesmade in the final regulation compared tothe proposed requirements, the Agencyhas reexamined and updated the earlieranalyses.

2. Revised Cost AnalysisAs indicated earlier, there have been

a number of changes made in theregulations that are expected to increasethe cost of compliance. In addition, theFederal tax code was changed in late1986, the cost of goods and services tothe economy as a whole has increaseddue to inflation, and the estimated costof specific requirements associated withthe BIF regulations have beenreexamined. The new analysis focusedon assessing the Impact of changes incompliance costs on typical facilities,and did not reexamine the impact ofthese changes on the selection ofregulatory options by individualfacilities. In addition, no effort wasmade to explicitly examine the impact ofthe final rules on the economiccompetitiveness of individual firms orindustries, nor on the reduction in publichealth risks.

The primary changes that haveoccurred in the regulations subsequentto proposal have been revisedrequirements for continuous emissionmonitoring of CO and HC; addition ofthe PM standard, interim statuscompliance procedures, and limits onemissions of several additional metalsand CL.; and increases In recordkeeping,sampling, and analysis requirements.The impact of these changes plus theimpact of tax code changes and inflationon the before- and after-tax costs of theBIF regulations are summarized in Table1. When combined with the original"base case" cost estimates prepared in1986, the revised cost estimate for thepromulgated rule is $15.2 million peryear before taxes and $10.3 million peryear after-taxes.

The increased cost for CO and HCmonitoring reflects the costs forinstallation of a more comprehensiveCO monitoring system than wasoriginally estimated and the cost ofinstalling HC monitors on an estimated20 devices (primarily cement kilns) thatwill operate under the Tier II CO andHC limits. The zero cost increaseassociated with the PM emissionstandard reflects the expectation thatBIFs complying with the metalsstandards will achieve the 0.08 gr/dscfstandard, and that most existing

industrial furnaces and some boilers arealready subject to this emission level (ora more stringent level) as the result ofState Implementation Plans or NewSource Performance Standards. As aresult, no Incremental increase forcompliance with the PM emission limitis projected.

The additional costs for interim statuscompliance reflects the increase inannualized costs [over a 10 year period)for preparation of the precomplianceand compliance certification packages(including compliance testing) byapproximately 150 BIFs. The additionalcost for the C2 standard is based on theincremental cost of analysis for C12beyond that already required todetermined HCI emissions.

The increase in annual recordkeeping,sampling, and analysis costs reflects areassessment of the estimated costs inthe 1986 analysis. These increased costsreflect a before-tax increase ofapproximately $2.4 million forrecordkeeping and $0.6 million forsampling and analysis.

The impact of the 1986 tax codechanges was to reduce the marginal taxrate imposed on before-tax profits and,thus, has the affect of increasing theimpact of compliance costs on after-taxprofits. As a result, the change in the1986 tax code is to increase the after-taxcost of the regulations by an estimated$0.6 million per year. The increase incosts due to inflation reflects anestimated increase in compliance cost of20 percent between the time of theinitial analysis (based on 1985 dollars)and 1990.

TABLE 1

Cost element Before Altar taxes Notetaxes

CO and HCMonitoring ....... 1,930,000 1,200,000 1

PM Standard 0 0 2interim Status

Compliance 960.000 590,000 3C6 Standards 30,000 20.000 4Recordkeep-

Ing/Sampling& Analysis ....... 3,050,000 1,700,000 5

Tax CodeChanges .......... 0 600,000 B

inflation .............. 1,640,000 980,000 7

Total ......... 7,630,000 5,090.000

Notes:1. Based on Installing 20 CO monitors using cap-

ital and O&M costs from the revised ICR.2. No incremental costs because BIFs already

meet standard by meeting metals limits and existingSIP and NSPS limits.

3. Assumes all not small quantity burner BIFssubmit precompliance and compliance certificationpackages. 50% of BIFs submit a revised certificationof precompiance, and 75% of compliance test canbe used in lieu of the trial burn to obtain an operat-ing permit, thus reducing the cost of the Part Bpermit

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4. Assumes all BIFS complying with emissionslimits (and not Tier I teed rate limits) conduct C12teS during compliance certification and trial bumtests ($165/sample).

5. Increases waste sampling and analysis costsover those estimated at proposal for all non-small

euantity burners by $300/month. Provides an addi-tional 16 hours per month for all non-small quantityburners and 2 hours per month for small quantityburners for additional recordkeeping.

6. The 1986 revisions to the Federal tax codereduced the Federal marginal tax rate (MTR) from48% to 34%. The 1986 analysis assumed a MTR of50% (48% Federal plus 2% State). The revisedanalysis assumes a MTR of 40% (34% Federal plus6% State).

7. Adjustment for 20% Inflation between 1985 and1990 ($8.2 million before tax cost estimate In 1985dollars, adjusted to after-tax basis assuming a mar-ginal tax rate of 40%.

B. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA)requires Federal regulatory agencies toevaluate the impacts of regulations onsmall entities. The RFA requires aninitial screening analysis to determinewhether the proposed rule will have asignificant impact on a substantialnumber of small businesses. Asindicated at proposal (52 FR 17030), theAgency estimates that a substantialnumber of small entities will not besignificantly impacted by the rule.Although the Agency estimates thatchanges to the rule since proposal andre-evaluation of some cost estimatesmade during the initial impact analysiswill result in a higher cost to theregulated industry, the Agencycontinues to believe that a substantialnumber of small entities will not besignificantly impacted by the rule.

C. Paperwork Reduction ActThe information collection

requirements In this rule have beensubmitted for approval to the Office ofManagement and Budget (OMB) underthe Paperwork Reduction Act 44 U.S.C.3501 et seq., and assigned OMB Controlnumber 2050-0073.

II1. List of Subjects In 40 CFR Parts 260,261, 264, 265, 266, 270, and 271

Administrative practices andprocedures, Confidential businessinformation, Hazardous materialstransportation, Hazardous waste, Indianlands, Insurance, Incorporation byreference, Intergovernmental relations,Packaging and containers, Penalties,Recycling, Reporting and recordkeepingrequirements, Security measures,Security bonds, Water pollution control,Water supply.

Dated: December 31, 1990.F. Henry Habicht II,Deputy Administrator and ActingAdministrator.

PART 260-HAZARDOUS WASTEMANAGEMENT SYSTEM: GENERAL

I. In part 260:

1. The authority citation for part 260continues to read as follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921through 6927, 6930, 6934, 6935, 6937, 6938,6939, and 6974.

2. Section 260.10 is amended by: (1)revising the introductory text; (2]revising the definition of "incinerator";(3) amending the definition of "industrialfurnace" by revising the introductorytext and redesignating paragraph (12] as(13) and by adding new paragraph (12);and (4) adding, in alphabetical order,definitions for "carbon regenerationunit", "infrared incinerator", "plasmaarc incinerator" and "sludge dryer" toread as follows:

§ 260.10 Definitions.

When used in parts 260 through 266and 268 of this chapter, the followingterms have the meanings given below:* * * * *

Carbon regeneration unit means anyenclosed thermal treatment device usedto regenerate spent activated carbon.* * * * *

Incinerator means any encloseddevice that:

(1) Uses controlled flame combustionand neither meets the criteria forclassification as a boiler, sludge dryer,or carbon regeneration unit, nor is listedas an industrial furnace; or

(2) Meets the definition of infraredincinerator or plasma arc incinerator.* * * * *

Industrialfurnace means any of thefollowing enclosed devices that areintegral components of manufacturingprocesses and that use thermaltreatment to accomplish recovery ofmaterials or energy:* * * * *

(12) Halogen acid furnaces (HAFs) forthe production of acid from halogenatedhazardous waste generated by chemicalproduction facilities where the furnaceis located on the site of a chemicalproduction facility, the acid product hasa halogen acid content of at least 3%, theacid product is used in a manufacturingprocess, and, except for hazardouswaste burned as fuel, hazardous wastefed to the furnace has a minimumhalogen content of 20% as-generated.* * * * *

Infrared incinerator means anyenclosed device that uses electricpowered resistance heaters as a sourceof radiant heat and which is not listedas an industrial furnace.* * * * *

Plasma arc incinerator means anyenclosed device using a high intensityelectrical discharge or arc as a source of

heat and which is not listed as anindustrial furnace.* * * * *

Sludge dryer means any enclosedthermal treatment device that is used todehydrate sludge and that has amaximum total thermal input, excludingthe heating value of the sludge Itself, of2,500 Btu/lb of sludge treated on a wet-weight basis.* * * * *

3. Paragraph (a) of § 260.11 isamended by adding to the first listingthe following reference in alphabeticalorder

§ 260.11 References.(a) * * *U.S. EPA, Screening Procedures for

Estimating the Air Quality Impact ofStationary Sources, August 1988,Available from the National TechnicalInformation Service (NTIS), 5285 PortRoyal Road, Springfield, VA 22161, (703)487-4600. The document number isPB89-159-396.* * * * #

PART 261-IDENTIFICATION ANDLISTING OF HAZARDOUS WASTE

II. In part 261:1. The authority citation for part 261

continues to read as follows:Authority: 42 U.S.C. 6905, 6912(a), 6921,

6922, and 6938.

2. Section 261.2 is amended byredesignating paragraph (d)(2) as (d)(3)and adding new paragraph (d)(2) to readas follows:

§ 261.2 Definition of solid waste.* * * * *

(d) * *(2) Secondary materials fed to a

halogen acid furnace that exhibit acharacteristic of a hazardous waste orare listed as a hazardous waste asdefined in subparts C or D of this part.

3. Section 261.4 is amended by addingparagraph (a)(10) and revisingparagraphs (b)(4), the first sentence of(b)(7), and (b)(8) to read as follows:

§ 261.4 Exclusions.(a) * * *(10] When used as a fuel, coke and

coal tar from the iron and steel industrythat contains or is produced fromdecanter tank tar sludge, EPAHazardous Waste K087. The process ofproducing coke and coal tar from suchdecanter tank tar sludge in a coke otvenis likewise excluded from regulation.

(b) * * *(4] Fly ash waste, bottom ash waste,

slag waste, and flue gas emissioncontrol waste, generated primarily from



Federal Register / VoL 56, No. 35 / Thursday, February 21,' 1991 / Rules and Regulations

the combusion of coal or other fossilfuels, except as provided by § 266.112 ofthis chapter for facilities that burn orprocess hazardous waste.

(7) Solid waste from the extraction,beneficiation and processing of oresand minerals (including coal, phosphaterock and overburden from the mining ofuranium ore), except as provided by§ 266.112 of this chapter for facilitiesthat burn or process hazardous waste.

(8) Cement kiln dust waste, except asprovided by § 266.112 of this chapter forfacilities that burn or process hazardouswaste.

4. Section 261.6 is amended byremoving paragraph (a)(3)(vii) andredesignating paragraphs (a)(3) (viii)and (ix) as (a)(3) (vii) and (viii)respectively.

PART 264-STANDARDS FOROWNERS AND OPERATORS OFHAZARDOUS WASTE TREATMENT,STORAGE, AND DISPOSALFACIUTIES

IlL In part 264:1. The authority citation for part 264

continues to read as follows:

Authority- 42 U.S.C. 6905, 6912(a), 6924, and6925.

2. Section 264.112 is amended byrevising paragraph (d)(1) to read asfollows:

§ 264.112 Closure of plan; amendment ofplan.

(d) Notification of partial closure andfinal closure. (1) The owner or operatormust notify the Regional Administratorin writing at least 60 days prior to thedate on which he expects to beginclosure of a surface impoundment,waste pile, land treatment or landfillunit, or final closure of a facility withsuch a unit. The owner or operator mustnotify the Regional Administrator inwriting at least 45 days prior to the dateon which he expects to begin finalclosure of a facility with only treatmentor storage tanks, container storage, orincinerator units to be closed. Theowner or operator must notify theRegional Administrator in writing atleast 45 days prior to the date on whichhe expects to begin partial or finalclosure of a boiler or industrial furnace,whichever is earlier.

3. Section 264.340 is amended byrevising paragraph (a) to read asfollows:

§ 264.340 Applicability.(a) The regulations of this subpart

apply to owners and operators ofhazardous waste incinerators (asdefined in § 260.10 of this chapter),except as § 24.1 provides otherwise.

PART 26--INTERIM STATUSSTANDARDS FOR OWNERS ANDOPERATORS OF HAZARDOUS WASTETREATMENT, STORAGE, ANDDISPOSAL FACILITIES

IV. In part 265:1. The authority citation for part 265


Authority: 42 U.S.C. 6905, 6912(a), 6924,6925, and 6935.

2. Section 265.112 is amended byrevising paragraphs (a), (d)(1), and (d)(2)to read as follows:

§ 265.112 Closure plan; amendment ofplan.

(a) Written plan. By May 19, 1981, orby six months after the effective date ofthe rule that first subjects a facility toprovisions of this section, the owner oroperator of a hazardous wastemanagement facility must have awritten closure plan. Until final closureis completed and certified in accordancewith § 265.115, a copy of the mostcurrent plan must be furnished to theRegional Administrator upon request,including request by mail. In addition.for facilities without approved plans, itmust also be provided during siteinspections, on the day of inspection, toany officer, employee, or representativeof the Agency who is duly designated bythe Administrator.• * • • *

(d) Notification of partial closure andfinal closure. (1) The owner or operatormust submit the closure plan to theRegional Administrator at least 180 daysprior to the date on which he expects tobegin closure of the first surfaceimpoundment, waste pile, landtreatment, or landfill unit, or finalclosure if it involves such a unit,whichever is earlier. The owner oroperator must submit the closure plan tothe Regional Administrator at least 45days prior to the date on which heexpects to begin partial or final closureof a boiler or industrial furnace. Theowner or operator must submit theclosure plan to the RegionalAdministrator at least 45 days prior tothe date on which he expects to beginfinal closure of a facility with onlytanks, container storage, or incineratorunits. Owners or operators withapproved closure plans must notify theRegional Administrator in writing at

least 60 days prior to the date on whichhe expects to begin closure of a surfaceimpoundment, waste pile, landfill, orland treatment unit, or final closure of afacility involving such a unit. Owners oroperators with approved closure plansmust notify the Regional Administratorin writing at least 45 days prior to thedate on which he expects to beginpartial or final closure of a boiler orindustrial furnace. Owners or operatorswith approved closure plans must notifythe Regional Administrator in writing atleast 45 days prior to the date on whichhe expects to begin final closure of afacility with only tanks, containerstorage, or incinerator units.

(2) Except for boilers and industrialfurnaces that operate under interimstatus as specified by § 266.103(c)(7)(i)(B) or (C), the date when he "expects tobegin closure" must be either within 30days after the date on which anyhazardous waste management unitreceives the known final volume ofhazardous wastes, or, if there is areasonable possibility that thehazardous waste management unit willreceive additional hazardous wastes, nolater than one year after the date onwhich the unit received the most recentvolume of hazardous waste. If the owneror operator of a hazardous wastemanagement unit can demonstrate to theRegional Administrator that thehazardous waste management unit orfacility has the capacity to receiveadditional hazardous wastes and he hastaken, and will continue to take, allsteps to prevent threats to human healthand the environment, includingcompliance with all interim statusrequirements, the RegionalAdministrator may approve anextension to this one-year limit. Forboilers and industrial furnaces thatoperate under interim status as specifiedby § 266.103(c)(7)(i) (B) or (C), the datewhen he "expects to begin closure" mustbe within 30 days after failure to submita complete certification of complianceby the applicable deadline under§ 266.103(c)(7)(i) (B) or (C).

3. Section 265.113 is amended byrevising paragraphs (a), introductorytext, and (b), introductory text, to readas follows:

§ 265.113 Closure; Ume allowed forclosure.

(a) Within 90 days after receiving thefinal volume of hazardous wastes at ahazardous waste management unit orfacility, or within 90 days after approvalof the closure plan. whichever is later,or, for a boiler or industrial furnace thatdoes not submit a complete certification

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of compliance by the applicabledeadline under § 266.103(c)(7)(i) (B) or(C), within 90 days after the applicabledeadline, the owner or operator musttreat, remove from the unit or facility ordispose of on-site, all hazardous wastesin accordance with the approved closureplan. The Regional Administrator mayapprove a longer period if the owner oroperator demonstrates that:* * * * *

(b) The owner or operator mustcomplete partial or final closureactivities in accordance with theapproved closure plan and within 180days after receiving the final volume ofhazardous wastes at the hazardouswaste management unit or facility, or180 days after approval of the closureplan, if that is later, or, for a boiler orindustrial furnace that does not submit acomplete certification of compliance bythe applicable deadline under§ 266.103(c)(7)(i) (B) or (C), within 180days after the applicable deadline. TheRegional Administrator may approve anextenstion to the closure period if theowner or operator demonstrates that:

4. Section 265.340 is amended byrevising paragraph (a) to read asfollows:

§ 265.340 Applicability.

(a) The regulations of this subpartapply to owners and operators ofhazardous waste incinerators (asdefined in § 260.10 of this chapter),except as § 265.1 provides otherwise.* * * * *

PART 266--STANDARDS FOR THEMANAGEMENT OF SPECIFICHAZARDOUS WASTES AND SPECIFICTYPES OF HAZARDOUS WASTEMANAGEMENT FACILITIES

V. In part 260:1. The authority citation for part 266

continues to read as follows:Authority: Secs. 1006, 2002(a), 3004, and

3014 of the Solid Waste Disposal Act, asamended by the Resource Conservation andRecovery Act of 197%, as amended (42 U.S.C.6905, 6912(a), 6924, and 6934).

2. Subpart D is hereby removed andreserved and subpart H is added to readas follows:Subpart H-Hazardous Waste Burned InBoilers and Industrial FurnacesSec.266.100 Applicability.266.101 Management prior to burning.266.102 Permit standards for burners.206.103 Interim status standards for burners.266.104 Standards to control organic

emissions.

Sec.266.105 Standards to control particulate

matter.266.106 Standards to control metals

emissions.266.107 Standards to control hydrogen

chloride (HCI} and chlorine gas (C2)emissions.

266.108 Small quantity on-site burnerexemption.

268.109 Low risk waste exemption.268.110 Waiver of DRE trial burn for boilers.266.111 Standards for direct transfer.266.112 Regulation of residues.

§ 266.100 Applicability.(a) The regulations of this subpart

apply to hazardous waste burned orprocessed in a boiler or industrialfurnace (as defined in § 260.10 of thischapter) irrespective of the purpose ofburning or processing, except asprovided by paragraphs (b), (c), and (d)of this section. In this subpart, the term"burn" means burning for energyrecovery or destruction, or processingfor materials recovery or as aningredient. The emissions standards of§ § 266.104, 266.105, 266.106, and 266.107apply to facilities operating underinterim status or under a RCRAoperating permit as specified in§ § 266.102 and 266.103.

(b) The following hazardous wastesand facilities are not subject toregulation under this subpart:

(1) Used oil burned for energyrecovery that is also a hazardous wastesolely because it exhibits acharacteristic of hazardous wasteidentified in subpart C of part 261 of thischapter. Such used oil is subject toregulation under subpart E of part 266rather than this subpart;

(2) Gas recovered from hazardous orsolid waste landfills when such gas isburned for energy recovery.

(3) Hazardous wastes that are exemptfrom regulation under § § 261.4 and261.6(a)(3) (v-viii) of this chapter, andhazardous wastes that are subject to thespecial requirements for conditionallyexempt small quantity generators under§ 261.5 of this chapter.

(4) Coke ovens, if the only hazardouswaste burned is EPA Hazardous WasteNo. K087, decanter tank tar sludge fromcoking operations.

(c) Owners and operators of smelting,melting, and refining furnaces (includingpyrometallurgical devices such ascupolas, sintering machines, roasters,and foundry furnaces, but'not includingcement kilns, aggregate kilns, or halogenacid furnaces burning hazardous waste)that process hazardous waste solely formetal recovery are conditionally exemptfrom regulation under this subpart,except for § § 266.101 and 266.112.

(1) To be exempt from § § 266.102through 266.111, an owner or operatormust:

(i) Provide a one-time written noticeto the Director indicating the following:

(A) The owner or operator claimsexemption under this paragraph;

(B) The hazardous waste is burnedsolely for metal recovery consistent withthe provisions of paragraph (c)(2) of thissection;

(C) The hazardous waste containsrecoverable levels of metals; and

(D) The owner or operator will complywith the sampling and analysis andrecordkeeping requirements of thisparagraph;

(ii) Sample and analyze the hazardouswaste and other feedstocks asnecessary to comply with therequirements of this paragraph underprocedures specified by Test Methodsfor Evaluating Solid Waste, Physical/Chemical Methods, SW-846,incorporated by reference in § 260.11 ofthis chapter, and

(iii) Maintain at the facility for at leastthree years records to documentcompliance with the provisions of thisparagraph including limits on levels oftoxic organic constituents and Btu valueof the waste, and levels of recoverablemetals in the hazardous wastecompared to normal nonhazardouswaste feedstocks.. (2) A hazardous waste meeting eitherof the following criteria is not processedsolely for metal recovery:

(i) The hazardous waste has a totalconcentration of organic compoundslisted in part 261, appendix VIII, of thischapter exceeding 500 ppm by weight,as-generated, and so is considered to beburned for destruction; or

(ii) The hazardous waste has aheating value of 5,000 Btu/lb or more,as-generated or as-fired into the furnace,and so is considered to be burned asfuel.

(d) The standards for direct transferoperations under § 266.111 apply only tofacilities subject to the permit standardsof § 266.102 or the interim statusstandards of § 266.103.

(e) The management standards forresidues under § 266.112 apply to anyboiler or industrial furnace burninghazardous waste.

(Approved by the Office of Management andBudget under control number 2050-0073)

§ 266.101 Management prior to burning.(a) Generators. Generators of

hazardous waste that is burned in aboiler or industrial furnace are subjectto part 262 of this chapter.

(b) Transporters. Transporters ofhazardous waste that is burned in a




boiler or industrial furnace are subjectto part 263 of this chapter.

(c) Storage facilities. (1) Owners andoperators of facilities that storehazardous waste that is burned in aboiler or industrial furnace are subjectto the applicable provisions of subpartsA through L of part 264, subparts Athrough L of part 265, and part 270 ofthis chapter, except as provided byparagraph (c)(2) of this section. Thesestandards apply to storage by the burneras well as to storage facilities operatedby intermediaries (processors, blenders,distributors, etc.) between the generatorand the burner.

(2) Owners and operators of facilitiesthat bum, in an on-site boiler orindustrial furnace exempt fromregulation under the small quantityburner provisions of § 266.108,hazardous waste that they generate areexempt from regulation under subpartsA through L of part 264, subparts Athrough L of part 265, and part 270 ofthis chapter with respect to the storageof mixtures of hazardous waste and theprimary fuel to the boiler or industrialfurnace in tanks that feed the fuelmixture directly to the burner. Storage ofhazardous waste prior to mixing withthe primary fuel is subject to regulationas prescribed in paragraph (c)(1) of thissection.

§ 266.102 Permit standards for burners.(a) Applicability-(1) General.

Owners and operators of boilers andindustrial furnaces burning hazardouswaste and not operating under interimstatus must comply with therequirements of this section and§ § 270.22 and 270.66 of this chapter,unless exempt under the small quantityburner exemption of § 266.108.

(2) Applicability of part 264standards. Owners and operators ofboilers and industrial furnaces that bumhazardous waste are subject to thefollowing provisions of part 264 of thischapter, except as provided otherwiseby this subpart:

(i) In subpart A (General), 264.4;(ii) In subpart B (General facility

standards), § § 264.11-264.18;(iii) In subpart C (Preparedness and

prevention), U § 264.31-264.37;(iv) In subpart D (Contingency plan

and emergency procedures), § § 264.51-264.56;

(v) In subpart E (Manifest system,recordkeeping, and reporting), theapplicable provisions of § U 264.71-264.77;

(vi) In subpart F (Corrective Action),§ 264.90 and 204.101;

(vii) In subpart G (Closure and post-closure), §§ 264.111-264.115;

(viii) In subpart H (Financialrequirements), § § 264.141, 264.142,264.143, and 264.147-264.151, except thatStates and the Federal government areexempt from the requirements ofsubpart H; and

(ix) Subpart BB (Air emissionstandards for equipment leaks), except§ 264.1050(a).

(b) Hazardous waste analysis. (1) Theowner or operator must provide ananalysis of the hazardous waste thatquantifies the concentration of anyconstituent identified in appendix VIII ofpart 261 of this chapter that mayreasonably be expected to be in thewaste. Such constituents must beidentified and quantified if present, atlevels detectable by analyticalprocedures prescribed by Test Methodsfor the Evaluation of Solid Waste,Physical/Chemical Methods(incorporated by reference, see § 260.11of this chapter). The appendix VIII, part261 constituents excluded from thisanalysis must be identified and thebasis for their exclusion explained. Thisanalysis will be used to provide allinformation required by this subpart and§ 270.22 and § 270.66 of this chapter andto enable the permit writer to prescribesuch permit conditions as necessary toprotect human health and theenvironment. Such analysis must beincluded as a portion of the part Bpermit application, or, for facilitiesoperating under the interim statusstandards of this subpart, as a portion ofthe trial bum plan that may besubmitted before the part B applicationunder provisions of J 270.66(g) of thischapter as well as any other analysisrequired by the permit authority inpreparing the permit. Owners andoperators of boilers and industrialfurnaces not operating under the interimstatus standards must provide theinformation required by § § 270.22 or270.66(c) of this chapter in the part Bapplication to the greatest extentpossible.

(2) Throughout normal operation, theowner or operator must conductsampling and analysis as necessary toensure that the hazardous waste, otherfuels, and industrial furnace feedstocksfired into the boiler or industrial furnaceare within the physical and chemicalcomposition limits specified in thepermit.

(c) Emissions standards. Owners andoperators must comply with emissionsstandards provided by U § 266.104through 266.107.

(d) Permits. (1) The owner or operatormay burn only hazardous wastesspecified in the facility permit and onlyunder the operating conditions specifiedunder paragraph (e) of this section;

except in approved trial bums under theconditions specified in § 270.66 of thischapter.

(2) Hazardous wastes not specified inthe permit may not be burned untiloperating conditions have beenspecified under a new permit or permitmodification, as applicable. Operatingrequirements for new wastes may bebased on either trial bum results oralternative data included with part B ofa permit application under § 270.22 ofthis chapter.

(3) Boilers and industrial furnacesoperating under the interim statusstandards of § 266,103 are permittedunder procedures provided by§ 270.66(g) of this chapter.

(4) A permit for a new boiler orindustrial furnace (those boilers andindustrial furnaces not operating underthe interim status standards) mustestablish appropriate conditions foreach of the applicable requirements ofthis section, including but not limited toallowable hazardous waste firing ratesand operating conditions necessary tomeet the requirements of paragraph (e)of this section, in order to comply withthe following standards:

(i) For the period beginning withinitial introduction of hazardous wasteand ending with initiation of the trialburn, and only for the minimum timerequired to bring the device to a point ofoperational readiness to conduct a trialburn, not to exceed a duration of 720hours operating time when burninghazardous waste, the operatingrequirements must be those most likelyto ensure compliance with the emissionstandards of § § 266.104 through 266.107,based on the Director's engineeringjudgment. If the applicant is seeking awaiver from a trial burn to demonstrateconformance with a particular emissionstandard, the operating requirementsduring this initial period of operationshall include those specified by theapplicable provisions of § 266.104,§ 266.105, § 266.106, or § 266.107. TheDirector may extend the duration of thisperiod for up to 720 additional hourswhen good cause for the extension isdemonstrated by the applicant.

(ii) For the duration of the trial burn,the operating requirements must besufficient to demonstrate compliancewith the emissions standards of§ § 266.104 through 266.107 and must bein accordance with the approved trialburn plan:

(iii) For the period immediatelyfollowing completion of the trial burn,and only for the minimum periodsufficient to allow sample analysis, datacomputation, submission of the trialburn results by the applicant, review of

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7210 federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

the trial burn results and modification ofthe facility permit by the Director toreflect the trial burn results, theoperating requirements must be thosemost likely to ensure compliance withthe emission standards § 1 266.104through 266.107 based on the Director'sengineering judgment.

(D) For the remaining duration of thepermit, the operating requirements mustbe those demonstrated in a trial burn orby alternative data specified in 1 270.22of this chapter, as sufficient to ensurecompliance with the emissionsstandards of § § 266.104 through 266.107.

(e) Operating requirements--(1)General. A boiler or industrial furnaceburning hazardous waste must beoperated in accordance with theoperating requirements specified in thepermit at all times where there ishazardous waste in the unit.

(2) Requirements to ensurecompliance with the organic emissionsstandards- (I) DRE standard.Operating conditions will be specifiedeither on a case-by-case basis for eachhazardous waste burned as thosedemonstrated (in a trial burn or byalternative data as specified in § 270.22)to be sufficient to comply with thedestruction and removal efficiency(DRE) performance standard of§ 266.104(a) or as those specialoperating requirements provided by§ 266.104(a)(4) for the waiver of the DREtrial burn. When the DRE trial burn isnot waived under § 266.104(a)(4), eachset of operating requirements willspecify the composition of thehazardous waste (including acceptablevariations in the physical and chemicalproperties of the hazardous waste whichwill not affect compliance with the DREperformance standard) to which theoperating requirements apply. For eachsuch hazardous waste, the permit willspecify acceptable operating limitsincluding, but not limited to, thefollowing conditions as appropriate:

(A) Feed rate of hazardous waste andother fuels measured and specified asprescribed in paragraph (e)(6) of thissection;

(B) Minimum and maximum deviceproduction rate when producing normalproduct expressed in appropriate units,measured and specified as prescribed inparagraph (e)(6) of this section;

(C) Appropriate controls of thehazardous waste firing system;

(D) Allowable variation in boiler andindustrial furnace system design oroperating procedures;

(E) Minimum combustion gastemperature measured at a locationindicative of combustion chambertemperature, measured and specified as

prescribed in paragraph (e)(6) of thissection;

(F) An appropriate indicator ofcombustion gas velocity, measured andspecified as prescribed in paragraph(e)(6) of this section, unlessdocumentation is provided under§ 270.66 of this chapter demonstratingadequate combustion gas residencetime; and

(G) Such other operating requirementsas are necessary to ensure that the DREperformance standard of § 266.104(a) ismet.

(ii) Carbon monoxide andhydrocarbon standards. The permitmust incorporate a carbon monoxide(CO) limit and, as appropriate, ahydrocarbon (HC limit as provided byparagraphs (b), (c), (d), (e) and (f) of§ 266.104. The permit limits will bespecified as follows:

(A) When complying with the COstandard of § 266.104(b)(1), the permitlimit is 100 ppmv;

(B) When complying with thealternative CO standard under§ 266.104(c), the permit limit for CO isbased on the trial burn and isestablished as the average over all validruns of the highest hourly rollingaverage CO level of each run, and thepermit limit for HC is 20 ppmv (asdefined in § 266.104(c)(1)), except asprovided in § 266.104(f).

(C) When complying with thealternative HC limit for industrialfurnaces under § 266.104(f), the permitlimit for HC and CO is the baseline levelwhen hazardous waste is not burned asspecified by that paragraph.

(iii) Start-up and shut-down. Duringstart-up and shut-down of the boiler orindustrial furnace, hazardous waste(except waste fed solely as aningredient under the Tier I (or adjustedTier I) feed rate screening limits formetals and chloride/chlorine, andexcept low risk waste exempt from thetrial bum requirements under§ § 266.104(a)(5), 266.105, 266.106, and266.107) must not be fed into the deviceunless the device is operating within theconditions of operation specified in thepermit.

(3) Requirements to ensureconformance with the particulatestandard. (i) Except as provided inparagraphs (e)(3) (ii) and (iii) of thissection, the permit shall specify thefollowing operating requirements toensure conformance with the particulatestandard specified in § 266.105:

(A) Total ash feed rate to the devicefrom hazardous waste, other fuels, andindustrial furnace feedstocks, measuredand specified as prescribed in paragraph(e)(6) of this section;

(B) Maximum device production ratewhen producing normal productexpressed in appropriate units, andmeasured and specified as prescribed inparagraph (e)(6) of this section;

(C) Appropriate controls on operationand maintenance of the hazardouswaste firing system and any airpollution control system;

(D) Allowable variation in boiler andindustrial furnace system designincluding any air pollution controlsystem or operating procedures; and

(E) Such other operating requirementsas are necessary to ensure that theparticulate standard in § 266.111(b) ismet.

(ii) Permit conditions to ensureconformance with the particulate matterstandard shall not be provided forfacilities exempt from the particulatematter standard under § 266.105(b);

(iii) For cement kilns and light-weightaggregate kilns, permit conditions toensure compliance with the particulatestandard shall not limit the ash contentof hazardous waste or other feedmaterials.

(4) Requirements to ensureconformance with the metals emissionsstandard. (i) For conformance with theTier I (or adjusted Tier I) metals feedrate screening limits of paragraphs (b) or(e) of § 266.106, the permit shall specifythe following operating requirements:

(A) Total feed rate of each metal inhazardous waste, other fuels, andindustrial furnace feedstocks measuredand specified under provisions ofparagraph (e)(6) of this section;

(B) Total feed rate of hazardous wastemeasured and specified as prescribed inparagraph (e)(6) of this section;

(C) sampling and metals analysisprogram for the hazardous waste, otherfuels, and industrial furnace feedstocks;

(ii) For conformance with the Tier Hmetals emission rate screening limitsunder § 266.106(c) and the Tier Ill metalscontrols under § 266.106(d), the permitshall specify the following operatingrequirements:

(A) Maximum emission rate for eachmetal specified as the average emissionrate during the trial bum;

(B) Feed rate of total hazardous wasteand pumpable hazardous waste, eachmeasured and specified as prescribed inparagraph (e)(6)(i} of this section;

(C) Feed rate of each metal in thefollowing feedstreams, measured andspecified as prescribed in paragraphs(e)(6) of this section:

(1) Total feed streams;(2) Total hazardous waste feed; and(3) Total pumpable hazardous waste

feed;




(13) Total feed rate of chlorine andchloride in total feed streams measuredand specified as prescribed in paragraph(e)(6) of this section;

(E) Maximum combustion gastemperature measured at a locationindicative of combustion chambertemperature, and measured andspecified as prescribed in paragraph(e)(6) of this section;

(F) Maximum flue gas temperature atthe inlet to the particulate matter airpollution control system measured andspecified as prescribed in paragraph(e)(6) of this section;

(G) Maximum device production ratewhen producing normal productexpressed in appropriate units andmeasured and specified as prescribed inparagraph (e)(6) of this section;

[H) Appropriate controls on operationand maintenance of the hazardouswaste firing system and any airpollution control system;

(I) Allowable variation in boiler andindustrial furnace system designincluding any air pollution controlsystem or operating procedures; and

(J) Such other operating requirementsas are necessary to ensure that themetals standards under § § 266.106(c) or266.106(d) are met.

(iii) For conformance with analternative implementation approachapproved by the Director under§ 266.106(f), the permit will specify thefollowing operating requirements:

(A) Maximum emission rate for eachmetal specified as the average emissionrate during the trial burn;

(B) Feed rate of total hazardous wasteand pumpable hazardous waste, eachmeasured and specified as prescribed inparagraph (e)(6)(i) of this section;

(C) Feed rate of each metal in thefollowing feedstreams, measured andspecified as prescribed in paragraph(e)(6) of this section:

(1) Total hazardous waste feed; and(2) Total pumpable hazardous waste

feed;(D) Total feed rate of chlorine and

chloride in total feed streams measuredand specified prescribed in paragraph(e)(6) of this section;

(E) Maximum combustion gastemperature measured at a locationindicative of combustion chambertemperature, and measured andspecified as prescribed in paragraph(e)(6) of this section;

(F Maximum flue gas temperature atthe inlet to the particulate matter airpollution control system measured andspecified as prescribed In paragraph(e)(6) of this section;

(G) Maximum device production ratewhen producing normal productexpressed in appropriate units and

measured and specified as prescribed inparagraph (e)(6) of this section;

(H) Appropriate controls on operationand maintenance of the hazardouswaste firing system and any airpollution control system;

(I) Allowable variation in boiler andindustrial furnace system designincluding any air pollution controlsystem or operating procedures; and

U) Such other operating requirementsas are necessary to ensure that themetals standards under § § 266.106(c) or266.106(d) are met.

(5) Requirements to ensureconformance with the hydrogen chlorideand chlorine gas standards. (i) Forconformance with the Tier I totalchloride and chlorine feed ratescreening limits of § 266.107(b)(1), thepermit will specify the followingoperating requirements:

(A) Feed rate of total chloride andchlorine in hazardous waste, other fuels,and industrial furnace feedstocksmeasured and specified as prescribed inparagraph (e)(6) of this section;

(B) Feed rate of total hazardous wastemeasured and specified as prescribed inparagraph (e)(6) of this section;

(C) A sampling and analysis programfor total chloride and chorline for thehazardous waste, other fuels, andindustrial furnace feestocks;

(ii) For conformance with the Tier IIHCl and Cl2 emission rate screeninglimits under § 266.107(b)(2) and the TierIII HCl and Cl2 controls under§ 266.107(c), the permit will specify thefollowing operating requirements:

(A) Maximum emission rate for HCIand for C12 specified as the averageemission rate during the trial burn;

(B) Feed rate of total hazardous wastemeasured and specified as prescribed inparagraph (e)(6) of this section;

(C) Total feed rate of chlorine andchloride in total feed streams, measuredand specified as prescribed in paragraph(e)(6) of this section;

(D) Maximum device production ratewhen producing normal productexpressed in appropriate units,measured and specified as prescribed inparagraph (e)(6) of this section;

(E) Appropriate controls on operationand maintenance of the hazardouswaste firing system and any airpollution control system;

(F) Allowable variation in boiler andindustrial furnace system designincluding any air pollution controlsystem or operating procedures; and

(G) Such other operating requirementsas are necessary to ensure that the HCland C12 standards under § 266.107 (b)(2)or (c) are met.

(6) Measuring paramenters andestablishing limits based on trial burn

data-i) General requirements. Asspecified in paragraphs (e)(2) through(e)(5) of this section, each operatingparameter shall be measured, andpermit limits on the parameter shall beestablished, according to either of thefollowing procedures:

(A) Instantaneous limits. A parametermay be measured and recorded on anInstantaneous basis (i.e., the value thatoccurs at any time) and the permit limitspecified as the time-weighted averageduring all valid runs of the trial burn; or

(B) Hourly rolling average. (1) Thelimit for a parameter may be establishedand continuously monitored on anhourly rolling average basis defined asfollows:

() A continuous monitor is one whichcontinuously samples the regulatedparameter without interruption, andevaluates the detector response at leastonce each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(hi An hourly rolling average is thearithmetic means of the 60 most recent1-minute average values recorded by thecontinuous monitoring system.

(2) The permit limit for the parametershall be established based on trial burndata as the average over all valid testruns of the highest hourly rollingaverage value for each run.

(ii) Rolling average limits forcarcinogenic metals and lead. Feed ratelimits for the carcinogenic metals (i.e.,arsenic, beryllium, cadmium andchromium) and lead may be establishedeither on an hourly rolling average basisas prescribed by paragraph (e)(6)(i) ofthis section or on (up to) a 24 hourrolling average basis. If the owner oropeator elects to use an average periodfrom 2 to 24 hours:

(A) The feed rate of each metal shallbe limited at any time to ten times thefeed rate that would be allowed on anhourly rolling average basis;

(B) The continuous monitor shall meetthe following specifications:

(1) A continuous monitor is one whichcontinuously samples the regulatedparameter without interruption, andevaluates the detector response at leastonce each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(2) The rolling average for the selectedaveraging period is defined as thearithmetic mean of the most recent onehour block average for the averageperiod. A one hour block average is thearithmetic mean of the one minuteaverages recorded during the 60-minuteperiod beginning at one minute after thebeginning of preceding clock hour, and

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7212 Federal Register'/ Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

(C) The permit limit for the feed rateof each metal shall be established basedon trial burn data as the average over allvalid test runs of the highest hourlyrolling average feed rate for each run.

(iii) Feed rate limits for metals, totalchloride and chlorine, and ash. Feedrate limits for metals, total chlorine andchloride, and ash are established andmonitored by knowing the concentrationof the substance (i.e., metals, chloride/chlorine, and ash) in each feedstreamapd the flow rate of the feedstream. Tomonitor the feed rate of thesesubstances, the flow rate of eachfeedstream must be monitored under thecontinuous monitoring requirements ofparagraphs (e)(6) (i) and (ii) of thissection.

(iv) Conduct of trial burn testing. (A)If compliance with all applicableemissions standards of § § 266L104through 266.107 is not demonstratedsimultaneously during a set of test runs,the operating conditions of additionaltest runs required to demonstratecompliance with remaining emissionsstandards must be as close as possibleto the original operating conditions.

(B) Prior to obtaining test data forpurposes of demonstrating compliancewith the emissions standards of§ § 266.104 through 266.107 orestablishing limits on operatingparameters under this section, thefacility must operate under trial burnconditions for a sufficient period toreach steady-state operations. TheDirector may determine, however, thatindustrial furnaces that recycle collectedparticulate matter back into the furnaceand that comply with an alternativeimplementation approach for metalsunder § 266.106(f), need not reach steadystate conditions with respect to the flowof metals in the system prior tobeginning compliance testing for metalsemissions.

(C) Trial burn data on the level of anoperating parameter for which a limitmust be established in the permit mustbe obtained during emissions samplingfor the pollutant(s) (i.e., metals, PM,HCI/C 2 , organic compounds) for whichthe parameter must be established asspecified by paragraph (e) of thissection.

(7) General requirements--(i) Fugitiveemissions. Fugitive emissions must becontrolled by:

(A) Keeping the combustion zonetotally sealed against fugitive emissions;or

(B) Maintaining the combustion zonepressure lower than atmosphericpressure; or

(C) An alternate means of controldemonstrated (with part B of the permitapplication) to provide fugitive

emissions control equivalent tomaintenance of combustion zonepressure lower than atmosphericpressure.

(ii) Automatic waste feed cutoff. Aboiler or industrial furnace must beoperated with a functioning system thatautomatically cuts off the hazardouswaste feed when operating conditionsdeviate from those established underthis section. The Director may limit thenumber of cutoffs per an operatingperiod on a case-by-case basis. Inaddition:

(A) The permit limit for (the indicatorof) minimum combustion chambertemperature must be maintained whilehazardous waste or hazardous wasteresidues remain in the combustionchamber,

(B) Exhaust gases must be ducted tothe air pollution control system operatedin accordance with the permitrequirements while hazardous waste orhazardous waste residues remain in thecombustion chamber; and

(C) Operating parameters for whichpermit limits are established mustcontinue to be monitored during thecutoff, and the hazardous waste feedshall not be restarted until the levels ofthose parameters comply with thepermit limits. For parameters that maybe monitored on an instantaneous basis,the Director will establish a minimumperiod of time after a waste feed cutoffduring which the parameter must notexceed the permit limit before thehazardous waste feed may be restarted.

(iii) Changes. A boiler or industrialfurnace must cease burning hazardouswaste when changes in combustionproperties, or feed rates of thehazardous waste, other fuels, orindustrial furnace feedstocks, orchanges in the boiler or industrialfurnace design or operating conditionsdeviate from the limits as specified inthe permit.

(8) Monitoring and Inspections. (i) Theowner or operator must monitor andrecord the following, at a minimum,while burning hazardous waste:

(A) If specified by the permit, feedrates and composition of hazardouswaste, other fuels, and industrialfurnace feedstocks, and feed rates ofash, metals, and total chloride andchlorine;

(B) If specified by the permit, carbonmonoxide (CO), hydrocarbons (HC), andoxygen on a continuous basis at acommon point in the boiler or industrialfurnace downstream of the combustionzone and prior to release of stack gasesto the atmosphere in accordance withoperating requirements specified Inparagraph (e)(2)(ii) of this section. CO,HC, and oxygen monitors must be

installed, operated, and maintained inaccordance with methods specified inappendix IX of this part.

(C) Upon the request of the Director,sampling and analysis of the hazardouswaste (and other fuels and industrialfurnace feedstocks as appropriate),residues, and exhaust emissions must beconducted to verify that the operatingrequirements established in the permitachieve the applicable standards of§ § 266.104, 266.105, 266.106, and 266.107.

(ii) All monitors shall record data inunits corresponding to the permit limitunless otherwise specified in the permit.

(ii) The boiler or industrial furnaceand associated equipment (pumps,values, pipes, fuel storage tanks, etc.)must be subjected to thorough visualinspection when It contains hazardouswaste, at least daily for leaks, spills,fugitive emissions, and signs oftampering.

(iv) The automatic hazardous wastefeed cutoff system and associatedalarms must be tested at least onceevery 7 days when hazardous waste Isburned to verify operability, unless theapplicant demonstrates to the Directorthat weekly inspections will undulyrestrict or upset operations and that lessfrequent inspections will be adequate.At a minimum, operational testing mustbe conducted at least once every 30days.

(v) These monitoring and inspectiondata must be recorded and the recordsmust be placed in the operating recordrequired by § 264.73 of this chapter.

(9) Direct transfer to the burner. Ifhazardous waste is directly transferredfrom a transport vehicle to a boiler orindustrial furnace without the use of astorage unit, the owner and operatormust comply with § 266.111.

(10) Recordkeeping. The owner oroperator must keep in the operatingrecord of the facility all information anddata required by this section for not lessthan three years.

(11) Closure. At closure, the owner oroperator must remove all hazardouswaste and hazardous waste residues(including, but not limited to, ash,scrubber waters, and scrubber sludges)from the boiler or industrial furnace.(Approved by the 'Office of Management andBudget under control number 2050-0073)

§ 266.103 Interim status standards forburners.

(a) Purpose, scope, applicability.--1)General. (i) The purpose of this sectionis to establish minimum nationalstandards for owners and operators of"existing" boilers and industrialfurnaces that bum hazardous wastewhere such standards define the*




acceptable management of hazardouswaste during the period of interimstatus. The standards of this sectionapply to owners and operators ofexisting facilities until either a permit Isissued under § 266.102(d) or until closureresponsibilities identified in this sectionare fulfilled.

(ii) Existing or in existence means aboiler or industrial furnace that on orbefore August 21, 1991 is either inoperation burning or processinghazardous waste or for whichconstruction (including the ancillaryfacilities to burn to process thehazardous waste) has commenced. Afacility has commenced construction ifthe owner or operator has obtained theFederal, State, and local approvals orpermits necessary to begin physicalconstruction; and either

(A) A continuous on-site, physicalconstruction program has begun; or

(B) The owner or operator has enteredinto contractual obligations-whichcannot be canceled or modified withoutsubstantial loss-for physicalconstruction of the facility to becompleted within a reasonable time.

(iii) If a boiler or industrial furnace islocated at a facility that already has apermit or interim status, then the facilitymust comply with the applicableregulations dealing with permitmodifications in § 270.42 or changes ininterim status in § 270.72 of this chapter.

(2) Exemptions. The requirements ofthis section do not apply to hazardouswaste and facilities exempt under§ § 268.100(b), or 266.108.

(3) Prohibition or burning dioxin-listed wastes. Hazardous waste listedfor dioxin or derived from any of thefollowing dioxin-listed wastes may notbe burned in a boiler or industrialfurnace operating under interim status:EPA Hazardous Waste Numbers F020,F021, F022, F023, F026, or F027.

(4) Applicability of part 265standards. Owners and operators ofboilers and industrial .furnaces that burnhazardous waste and are operatingunder interim status are subject to thefollowing provisions of part 265 of thischapter, except as provided otherwiseby this section:

(i) In subpart A (General), § 265.4;(ii) In subpart B (General facility

standards), § § 265.11-265.17;(iii) In subpart C (Preparedness and

prevention), § § 265.31-265.37;(iv) In subpart D (Contingency plan

and emergency procedures), § § 265.51-265.56;

(v) In subpart E (Manifest system,recordkeeping, and reporting),§ § 265.71-265.77, except that § 1 265.71,265.72, and 265.76 do not apply toowners and operators of on-site

facilities that do not receive anyhazardous waste from off-site sources;

(vi) In subpart G (Closure and post-closure), §§ 265.111-265.115;

(vii) In subpart H (Financialrequirements), § § 265.141, 265.142,265.143, and 265.147-265.151, except thatStates and the Federal government areexempt from the requirements ofsubpart H; and

(viii) Subpart BB (Air emissionstandards for equipment leaks), except§ 265.1050(a).

(5) Special requirements for furnaces.The following controls apply duringinterim status to industrial furnaces(e.g., kilns, cupolas) that feed hazardouswaste for a purpose other than solely asan ingredient (see paragraph (a)[5)(ii) ofthis section) at any location other thanthe hot end where products are normallydischarged and where fuels arenormally fired:

(i) Controls. (A) The hazardous wasteshall be fed at a location wherecombustion gas temperatures are atleast 1800 °F;

(B) The owner or operator mustdetermine that adequate oxygen ispresent in combustion gases to combustorganic constituents in the waste andretain documentation of suchdetermination in the facility record;

(C) For cement kiln systems, thehazardous waste shall be fed into thekiln; and

(D) The hydrocarbon controls of§ 266.104(c) or paragraph (c)(7)(ii) of thissection apply upon certification ofcompliance under paragraph (c) of thissection irrespective of the CO levelachieved during the compliance test.

(ii) Burning hazardous waste solely asan ingredient. A hazardous waste isburned for a purpose other than solelyas an ingredient if it meets either ofthese criteria:

(A) The hazardous waste has a totalconcentration of nonmetal compoundslisted in part 261, appendix VIII, of thischapter exceeding 500 ppm by weightas-generated (and, so, is considered tobe burned for destruction); or

(B) The hazardous waste has aheating value of 5,000 Btu/lb or more,as-generated or as-fired (and, so, isconsidered to be burned as fuel).(6) Restrictions on burning hazardous

waste that is not a fuel. Prior tocertification of compliance underparagraph (c) of this section, ownersand operators shall not feed hazardouswaste (other than hazardous wasteburned solely as an ingredient) In aboiler or Industrial furnace that has aheating value less than 5,000 Btu/Ib, as-generated, except for purposes ofcompliance testing (or testing prior to

compliance testing) for a total period oftime not to exceed 720 hours.

(7) Direct transfer to the burner. Ifhazardous waste is directly transferredfrom a transport vehicle to a boiler orindustrial furnace without the use of astorage unit, the owner and operatormust comply with § 266.111.

(b) Certification of precompliance-(1) General. The owner or operator mustprovide complete and accurateinformation specified in paragraph (b)(2)of this section to the Director on orbefore August 21, 1991, and mustestablish limits for the operatingparameters specified in paragraph (b)(3)of this section. Such information istermed a "certification ofprecompliance" and constitutes acertification that the owner or operatorhas determined that, when the facility isoperated within the limits specified inparagraph (b)(3) of this section, theowner or operator believes that, usingbest engineering judgment, emissions ofparticulate matter, metals, and HCI andCl2 are not likely to exceed the limitsprovided by § § 266.105, 266.106, and266.107. The facility may burn hazardouswaste only under the operatingconditions that the owner or operatorestablishes under paragraph (b)(3) ofthis section until the owner or operatorsubmits a revised certification ofprecompliance under paragraph (b)(8) ofthis section or a certification ofcompliance under paragraph (c) of thissection, or until a permit is issued.

(2) Information required. Thefollowing Information must be submittedwith the certification of precomplianceto support the determination that thelimits established for the operatingparameters identified in paragraph (b)(3)of this section are not likely to result inan exceedance of the allowableemission rates for particulate matter,metals, and HCI and Cl2:

(i) General facility information:(A) EPA facility ID number.(B) Facility name, contact person,

telephone number, and address;(C) Description of boilers and

industrial furnaces burning hazardouswaste, including type and capacity ofdevice;

(DJ A scaled plot plan showing theentire facility and location of the boilersand industrial furnaces burninghazardous waste; and

(E) A description of the air pollutioncontrol system on each device burninghazardous waste, including thetemperature of the flue gas at the inlet tothe particulate matter control system.

(ii) Except for facilities complyingwith the Tier I feed rate screening limitsfor metals or total chlorine and chloride

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provided by § § 266.106 (b) or (e) and-266.107 (b)(1) or (e) respectively, theestimated uncontrolled (at the inlet tothe air pollution control system)emissions of particulate matter, eachmetal controlled by § 266.106, andhydrogen chloride and chlorine, and thefollowing information to support suchdeterminations:

(A) The feed rate (lb/hr) of ash,chlorine, antimony, arsenic, barium,beryllium, cadmium, chromium, lead,mercury, silver, thallium in eachfeedstream (hazardous waste, otherfuels, industrial furnace feedstocks):I (B) The estimated partitioning factorto the combustion gas for the materialsidentified in paragraph (b)(ii)(A) of thissection and the basis for the estimateand an estimate of the partitioning toHCl and C12 ef total chloride andchlorine in feed materials. To estimatethe partitioning factor, the owner oroperator must use either bestengineering judgment or the proceduresspecified in appendix IX of this part.

(C) For industrial furnaces thatrecycle collected particulate matter (PM)back into the furnace and that willcertify compliance with the metalsemissions standards under paragraph(c)(3)(ii)(A), the estimated enrichmentfactor for each metal. To estimate theenrichment factor, the owner or operatormust use either best engineeringjudgment or the procedures specified in"Alternative Methodology forImplementing Metals Controls" inappendix IX of this part.

(D) If best engineering judgment isused to estimate partitioning factors orenrichment factors under paragraphs(b)(ii)(B) or (b)(ii)(C) respectively, thebasis for the judgment. When bestengineering judgment is used to developor evaluate data or information andmake determinations under this section,the determinations must be made by aqualified, registered professionalengineer and a certification of his/herdeterminations in accordance with§ 270.11(d) of this chapter must beprovided in the certification ofprecompliance.

(iii) For facilities complying with theTier I feed rate screening limits formetals or total chlorine and chlorideprovided by § § 266.106 (b) or (e) and266.107 (b)(1) or (e), the feed rate (lb/hr)of total chloride and chlorine, antimony,arsenic, barium, beryllium, cadmium,chromium, lead, mercury, silver, andthallium in each feedstream (hazardouswaste, other fuels, industrial furnacefeedstocks).

(iv) For facilities complying with theTier II or Tier III emission limits formetals or HCI and Cl6 (under § § 266.106(c) or (d) or 266.107(b)(2) or (c)), the

estimated controlled (outlet of the airpollution control system) emissionsrates of paticulate matter, each metalcontrolled by § 266.106, and HCI and C 2,and the following information to supportsuch determinations:

(A) The estimated air pollution controlsystem (APCS) removal efficiency forparticulate matter, HCI, CL2 , antimony,arsenic, barium, beryllium, cadmium,chromium, lead, mercury, silver, andthallium.

(B) To estimate APCS removalefficiency, the owner or operator mustuse either best engineering judgment orthe procedures prescribed in appendixIX of this part.

(C) If best engineering judgment isused to estimate APCS removalefficiency, the basis for the judgment.Use of best engineering judgment mustbe in conformance with provisions ofparagraph (b)(2)(ii)(D) of this section.

(v) Determination of allowableemissions rates for HCI, C2, antimony,arsenic, barium, beryllium, cadmium,chromium, lead, mercury, silver, andthallium, and the following informationto support such determinations:

(A) For all facilities:(1) Physical stack height,(2) Good engineering practice stack

height as defined by 40 CFR 51.100(ii);(3) Maximum flue gas flow rate;(4) Maximum flue gas temperature;(5) Attach a US Geological Service

topographic map (or eqivalent) showingthe facility location and surroundingland within 5 km of the facility.

(6) Identify terrain type: complex ornoncomplex; and

(7) Identify land use: urban or rural.(B) For owners and operators using

Tier III site specific dispersion modelingto determine allowable levels under§ 266.106(d) or § 266.107(c), or adjustedTier I feed rate screening limits under§ § 266.106(e) or 266.107(e):

(1) Dispersion model and versionused;

(2) Source of meterological data;(3) The dilution factor in micrograms

per cubic meter per gram per second ofemissions for the maximum annualaverage off-site (unless on-site isrequired) ground level concentration(MEI location); and

(4) Indicate the MEI location on themap required under paragraph(b)(2)(v)(A)(5); -

(vi) For facilities complying with theTier II or Ill emissions rate controls formetals or HC1 and C12, a comparison ofthe estimated controlled emissions ratesdetermined under paragraph (b)(2)(iv)with the allowable emission ratesdetermined under paragraph (b)(2)(v);

(vii) For facilities complying with theTier I (or adjusted Tier I) feed rate

screening limits for metals or totalchloride and chlorine, a comparison ofactual feed rates of each metal and totalchlorine and chloride determined underparagraph (b)(2)(iii) of this section to theTier I allowable feed rates; and

(viii) For industrial furnaces that feedhazardous waste for any purpose otherthan solely as an ingredient fas definedby paragraph (a)(5)(ii) of this section) atany location other than the productdischarge end of the device,documentation of compliance with therequirements of paragraphs (a)(5)(i) (A),(B), and (C) of this section.

(ix) For industrial furnaces thatrecycle collected particulate matter (PM)back into the furnace and that willcertify compliance with the metalsemissions standards under paragraph(c)(3)(ii) (A) of this section:

(A) The applicable particulate matterstandard in lb/hr; and

(B) The precompliance limit on theconcentration of each metal in collectedPM.

(3) Limits on operating conditions.The owner and operator shall establishlimits on the following parametersconsistent with the determinations madeunder paragraph (b)(2) of this sectionand certify (under provisions ofparagraph (b)(9) of this section) to theDirector that the facility will operatewithin the limits during interim statuswhen there is hazardous waste in theunit until revised certification ofprecompliance under paragraph (b)(8) ofthis section or certification ofcompliance under paragraph (c) of thissection:

(i) Feed rate of total hazardous wasteand (unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106(b) or(e)) pumpable hazardous waste;

(ii) Feed rate of each metal in thefollowing feed streams;

(A) Total feed streams, except thatindustrial furnaces that comply with thealternative metals implementationapproach under paragraph (b)(4) of thissection must specify limits on theconcentration of each metal in collectedparticulate matter in lieu of feed ratelimits for total feedstreams;

(B) Total hazardous waste feed; and(C) Total pumpable hazardous waste

feed, unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or(e);

(iii) Total feed rate of chlorine andchloride In total feed streams;. (iv) Total feed rate of ash in total feedstreams, except that the ash feed ratefor cement kilns and light-weightaggregate kilns is not limited, and




(v) Maximum production rate of thedevice in appropriate units whenproducing normal product.

(4) Operating requirements forfurnaces that recycle PM, Owners andoperators of furnaces that recyclecollected particulate matter (PM) backinto the furnace and that will certifycompliance with the metals emissionscontrols under paragraph (c)(3)(ii)(A) ofthis section must comply with thespecial operating requirements providedin "Alternative Methodology forImplementing Metals Controls" inappendix IX of this part.

(5) Measurement of feed rates andproduction rate-(i) Generalrequirements. Limits on each of theparameters specified in paragraph (b)(3)of this section (except for limits onmetals concentrations in collectedparticulate matter (PM) for industrialfurnaces that recycle collected PM) shallbe established and continuouslymonitored under either of the followingmethods:

(A) Instantaneous limits. A limit for aparameter may be established andcontinuously monitored on aninstantaneous basis (i.e., the value thatoccurs at any time) not to be exceededat any time; or

(B) Hourly rolling average limits. Alimit for a parameter may be establishedand continuously monitored on anhourly rolling average basis defined asfollows:

(1) A continuous monitor is one whichcontinuously samples the regulatedparameter without interruption, andevaluates the detector response at leastonce each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(2) An hourly rolling average is thearithmetic mean of the 60 most recent 1-minute average values recorded by thecontinuous monitoring system.

(ii) Rolling average limits forcarcinogenic metals and lead. Feed ratelimits for the carcinogenic metals(arsenic, beryllium, cadmium, andchromium) and lead may be establishedeither on an hourly rolling average basisas prescribed by paragraph (b)(5(i)(B)or on (up to) a 24 hour rolling averagebasis. If the owner or operator elects touse an averaging period from 2 to 24hours:

(A) The feed rate of each metal shallbe limited at any time to ten times thefeed rate that would be allowed on ahourly rolling average basis;

(B) The continuous monitor shall meatthe following specifications:

(1) A continuous monitor is one whichcontinuously samples the regulatedparameter without interruption, andevaluates the detector response at least

once each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(2) The rolling average for the selectedaveraging period is defined as thearithmetic mean of the most recent onehour block averages for the averagingperiod. A one hour block average is thearithmetic mean of the one minuteaverages recorded during the 60-minuteperiod beginning at one minute after thebeginning of preceding clock hour.

(iii) Feed rate limits for metals, totalchloride and chlorine, and ash. Feedrate limits for metals, total chlorine andchloride, and ash are established andmonitored by knowing the concentrationof the substance (i.e., metals, chloride/chlorine, and ash) in each feedstreamand the flow rate of the feedstream. Tomonitor the feed rate of thesesubstances, the flow rate of eachfeedstream must be monitored under thecontinuous monitoring requirements ofparagraphs (b)(5) (i) and (ii) of thissection.

(6) Public notice requirements atprecompliance. On or before [theeffective date of this rule] the owner oroperator must submit a notice with thefollowing information for publication ina major local newspaper of generalcirculation and send a copy of the noticeto the appropriate units of State andlocal government. The owner andoperator must provide to the Directorwith the certification of precomplianceevidence of submitting the notice forpublication. The notice, which shall beentitled "Notice of Certification ofPrecompliance with Hazardous WasteBurning Requirements of 40 CFR266.103(b)", must include:

(i) Name and address of the ownerand operator of the facility as well asthe location of the device burninghazardous waste;

(ii) Date that the certification ofprecompliance is submitted to theDirector;

(iii) Brief description of the regulatoryprocess required to comply with theinterim status requirements of thissection including required emissionstesting to demonstrate conformancewith emissions standards for organiccompounds, particulate matter, metals,and HCI and C12;

(iv) Types and quantities of hazardouswaste burned including, but not limitedto, source, whether solids or liquids, aswell as an appropriate description of thewaste;

(v) Type of device(s) in which thehazardous waste is burned including aphysical description and maximumproduction rate of each device;

(vi) Types and quantities of otherfuels and industrial furnace feedstocksfed to each unit;

(vii) Brief description of the basis forthis certification of precompliance asspecified in paragraph (b)(2) of thissection;

(viii) Locations where the operatingrecord for the facility can be viewed andcopied by interested parties. Theselocations shall at a minimum include:

(A) The Agency office where thesupporting documentation wassubmitted or another locationdesignated by the Director, and

(B) The facility site where the deviceis located;

(ix) Notification of the establishmentof a facility mailing list wherebyinterested parties shall notify theAgency that they wish to be placed onthe mailing list to receive futureinformation and notices about thisfacility; and

(x) Location (mailing address) of theapplicable EPA Regional Office,Hazardous Waste Division, wherefurther information can be obtained onEPA regulation of hazardous wasteburning.

(7) Monitoring other operatingparameters. When the monitoringsystems for the operating parameterslisted in paragraphs (c)(1)(v through xiii)of this section are installed andoperating in conformance with vendorspecifications or (for CO, HC, andoxygen) specifications provided byappendix IX of this part, as appropriate,the parameters shall be continuouslymonitored and records shall bemaintained in the operating record.

(8) Revised certification ofprecompliance. The owner or operatormay revise at any time the informationand operating conditions documentedunder paragraphs (b)(2) and (b)(3) of thissection in the certification ofprecompliance by submitting a revisedcertification of precompliance underprocedures provided by thoseparagraphs.

(i) The public notice requirements ofparagraph (b)(6) of this section do notapply to recertifications.

(ii) The owner and operator mustoperate the facility within the limitsestablished for the operating parametersunder paragraph (b)(3) of this sectionuntil a revised certification is submittedunder this paragraph or a certification ofcompliance is submitted underparagraph (c) of this section.

(9) Certification of precompliancestatement. The owner or operator mustinclude the following signed statementwith the certification of precompliancesubmitted to the Director:

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7216 Federal Register / Vol. §6, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

'I certify under penalty of law that thisinformation was prepared under my directionor supervision in accordance with a systemdesigned to ensure that qualified personnelproperly gathered and evaluated theinformation and supporting documentation.Copies of all emissions tests, dispersionmodeling results and other information usedto determine conformance with therequirements of I 266.103(b) are available atthe facility and can be obtained from thefacility contact person listed above. Based onmy inquiry of the person or persons whomanages the facility, or those personsdirectly responsible for gathering theinformation, the information submitted is, tothe best of my knowledge and belief, true,accurate, and complete. I am aware that thereare significant penalties for submitting falseinformation, including the possibility of fineand imprisonment for knowing violations.

I also acknowledge that the operatinglimits established in this certificationpursuant to I 268.103(b) (3) and (4) areenforceable limits at which the facility canlegally operate during interim status until: (1)A revised certification of precompliance issubmitted, (2) a certification of compliance issubmitted, or (3) an operating permit Isissued."

(c) Certification of compliance. On orbefore August 21, 1992, the owner oroperator shall conduct emissions testingto document compliance with theemissions standards of § § 266.104 (b)through (e), 266.105, 266.106, 266.107, andparagraph (a)(5)(i)(D) of this section,under the procedures prescribed by thisparagraph, except under extensions oftime provided by paragraph (c)(7). Basedon the compliance test, the owner oroperator shall submit to the Director acomplete and accurate "certification ofcompliance" (under paragraph (c)(4) 9fthis section) with those emissionstandards establishing limits on theoperating parameters specified inparagraph (c)(1).

(1) Limits on operating conditions.The owner or operator shall establishlimits on the following parameters basedon operations during the compliance test(under procedures prescribed inparagraph (c)(4)(iv) of this section) andinclude these limits with thecertification of compliance. The boiler orindustrial furnace must be operated inaccordance with these operating limitsat all times when there is hazardouswaste in the unit until an operatingpermit is issued.

(i) Feed rate of total hazardous wasteand (unless complying the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or(e)), pumpable hazardous waste;

(ii) Feed rate of each metal in thefollowing feedstreams:

(A) Total feedstreams, except thatindustrial furnaces that must complywith the alternative metals

Implementation approach underparagraph (c)(3)(ii) of this section mustspecify limits on the concentration ofeach metal in collected particulatematter in lieu of feed rate limits for totalfeedstreams;

(B) Total hazardous waste feed(unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 268.106 (b) or(e)); and

(C) Total pumpable hazardous wastefeed:

(iii) Total feed rate of chlorine andchloride in total feed streams;

(iv) Total feed rate of ash in total feedstreams, except that the ash feed ratefor cement kilns and light-weightedaggregate kilns is not limited;

(v) Carbon monoxide concentration,and where required, hydrocarbonconcentration in stack gas. Whencomplying with the CO controls of§ 266.104(b), the CO limit is 100 ppmv,and when complying with the HCcontrols of § 266.104(c), the HC limit is20 ppmv. When complying with the COcontrols of § 266.104(c), the CO limit isestablished based on the compliancetest;

(vi) Maximum production rate of thedevice in appropriate units whenproducing normal product;

(vii) Maximum combustion chambertemperature where the temperaturemeasurement is as close to thecombustion zone as possible and isupstream of any quench water injection,(unless complying with the Tier Iadjusted Tier I metals feed ratescreening limits under § 266.106 (b) or[e));

(viii) Maximum flue gas temperatureentering a particulate matter controldevice (unless complying with Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or(e})):

(ix) For systems using wet scrubbers,including wet ionizing scrubbers (unlesscomplying with the Tier I or adjustedTier I metals feed rate screening limitsunder § 266.106 (b) or (e) and the totalchlorine and chloride feed ratescreening limits under § 266.107(b) (1) or(e));

(A) Minimum liquid to flue gas ratio;(B) Minimum scrubber blowdown

from the system or maximum suspendedsolids content of scrubber water, and

(C) Minimum pH level of the scrubberwater;

(x) For systems using venturiscrubbers, the minimum differential gaspressure across the venturi (unlesscomplying the Tier I or adjusted Tier Imetals feed rate screening limits under§ 266.106 (b) or (e) and the total chlorine

and chloride feed rate screening limitsunder § 266.107(b) (1) or (e));(xi) For system using dry scrubbers(unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or(e) and the total chlorine and chloridefeed rate screening limits underU 266.107(b) (1) or (e));

(A) Minimum caustic feed rate; and(B) Maximum flue gas flow rate:(xii) For systems using wet ionizing

scrubbers or electrostatic precipitators(unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or(e) and the total chlorine and chloridefeed rate screening limits underU 266.107(b) (1) or (e));

(A) Minimum electrical power inkilovolt amperes (kVA) to theprecipitator plates; and

(B) Maximum flue gas flow rate;(xiii) For systems using fabric filters

(baghouses), the minimum pressure drop(unless complying with the Tier I oradjusted Tier I metals feed ratescreening limits under § 266.106 (b) or (e)and the total chlorine and chloride feedrate screening limits under§ 266.107(b)(1) or (e)).

(2) Prior notice of compliance testing.At least 30 days prior to the compliancetesting required by paragraph (c)(3) ofthis section, the owner or operator shallnotify the Director and submit thefollowing information:

(i) General facility informationincluding:

(A) EPA facility ID number,(B) Facility name, contact person,

telephone number, and address;(C) Person responsible for conducting

compliance test, including companyname, address, and telephone number,and a statement of qualifications;

(D) Planned date of the compliancetest;

(ii) Specific information on eachdevice to be tested including:

(A) Description of boiler or industrialfurnace;

(B) A scaled plot plan showing theentire facility and location of the boileror industrial furnace;

(C) A description of the air pollutioncontrol system;

(D) Identification of the continuousemission monitors that are installed,including:

(1) Carbon monoxide monitor;(2) Oxygen monitor,(3) Hydrocarbon monitor, specifying

the minimum temperature of the systemand. if the temperature is less than150 °C, an explanation of why a heatedsystem Is not used (see paragraph (c)(5)




of this section) and a brief description ofthe sample gas conditioning system;

(E) Indication of whether the stack Isshared with another device that will bein operation during the compliance test;

(F) Other information useful to anunderstanding of the system design oroperation.

(iii) Information on the testingplanned, including a complete copy ofthe test protocol and QualityAssurance/Quality Control (QA/QC)plan, and a summary description foreach test providing the followinginformation at a minimum:

(A) Purpose of the test (e.g.,demonstrate compliance with emissionsof particulate matter); and

(B) Planned operating conditions,including levels for each pertinentparameter specified in paragraph (c)(1)of this section.

(3) Compliance testing--(i) General.Compliance testing must be conductedunder conditions for which the owner oroperator has submitted a certification ofprecompliance under paragraph (b) ofthis section and under conditionsestablished in the notification ofcompliance testing required byparagraph (c)(2) of this section.

(ii) Special requirements for industrialfurnaces that recycle collected PM.Owners and operators of industrialfurnaces that recycle back into thefurnace particulate matter (PM) from theair pollution control system must complywith one of the following procedures fortesting to determine compliance with themetals standards of i 266.106(c) or (d):

(A) The special testing requirementsprescribed in "Alternative Method forImplementing Metals Controls" inappendix IX of this part; or

(B) Stack emissions testing for aminimum of 6 hours each day whilehazardous waste is burned duringinterim status. The testing must beconducted when burning normalhazardous waste for that day at normalfeed rates for that day and when the airpollution control system is operatedunder normal conditions. During interimstatus, hazardous waste analysis formetals content must be sufficient for theowner or operator to determine ifchanges in metals content may affect theability of the facility to meet the metalsemissions standards established under§ 266.106(c) or (d). Under this option,operating limits (under paragraph (c)(1)of this section) must be establishedduring compliance testing underparagraph (c)(3) of this section only onthe following parameters:

(1) Feed rate of total hazardous waste;(2) Total feed rate of chlorine and

chloride in total feed streams;

(3) Total feed rate of ash in total feedstreams, except that the ash feed ratefor cement kilns and light-weightaggregate kilns is not limited;

(4) Carbon monoxide concentration,and where required, hydrocarbonconcentration In stack gas;

(5) Maximum production rate of thedevice in appropriate units whenproducing normal product; or

(C) Conduct compliance testing todetermine compliance with the metalsstandards to establish limits on theoperating parameters of paragraph (c)(1)of this section only after the kiln systemhas been conditioned to enable it toreach equilibrium with respect to metalsfed into the system and metalsemissions. During conditioning,hazardous waste and raw materialshaving the same metals content as willbe fed during the compliance test mustbe fed at the feed rates that will be fedduring the compliance test.

(iii) Conduct of compliance testing.(A) If compliance with all applicableemissions standards of § 1266.104through 266.107 is not demonstratedsimultaneously during a set of test runs,the operating conditions of additionaltest runs required to demonstratecompliance with remaining emissionsstandards must be as close as possibleto the original operating conditions.

(B) Prior to obtaining test data forpurposes of demonstrating compliancewith the applicable emissions standardsof § § 266.104 through 266.107 orestablishing limits on operatingparameters under this section, thefacility must operate under compliancetest conditions for a sufficient period toreach steady-state operations. Industrialfurnaces that recycle collectedparticulate matter back into the furnaceand that comply with paragraphs(c)(3)(ii)(A) or (B) of this section,however, need not reach steady stateconditions with respect to the flow ofmetals in the system prior to beginningcompliance testing for metals.

(C) Compliance test data on the levelof an operating parameter for which alimit must be established in thecertification of compliance must beobtained during emissions sampling forthe pollutant(s) (i.e., metals, PM, HCI/Cl2, organic compounds) for which theparameter must be established asspecified by paragraph (c)(1) of thissection.

(4) Certification of compliance.Within 90 days of completingcompliance testing, the owner oroperator must certify to the Directorcompliance with the emissionsstandards of § § 266.104(b), (c), and (e),266.105, 266.106, 266.107, and paragraph(a)(5)(i)(D) of this section. The

certification of compliance must includethe following information:

(i) General facility and testinginformation including:

(A) EPA facility ID number;,(B) Facility name, contact person,

telephone number, and address;(C) Person responsible for conducting

compliance test, including companyname, address, and telephone number,and a statement of qualifications;

(D) Date(s) of each compliance test;(E) Description of boiler or industrial

furnace tested;(F) Person responsible for quality

assurance/quality control (QA/QC),title, and telephone number, andstatement that procedures prescribed inthe QA/QC plan submitted under§ 266.103(c)(2)(iii) have been followed,or a description of any changes and anexplanation of why changes werenecessary.

(G) Description of any changes in theunit configuration prior to or duringtesting that would alter any of theinformation submitted in the prior noticeof compliance testing under paragraph(c)(2) of this section, and an explanationof why the changes were necessary-

(H) Description of any changes in theplanned test conditions prior to orduring the testing that alter any of theinformation submitted in the prior noticeof compliance testing under paragraph(c)(2) of this section, and an explanationof why the changes were necessary; and

(I) The complete report on results ofemissions testing.

(ii) Specific information on each testincluding:

(A) Purpose(s) of test (e.g.,demonstrate conformance with theemissions limits for particulate matter,metals, HCL, C 2. and CO)

(B) Summary of test results for eachrun and for each test including thefollowing information:

(1) Date of run;(2) Duration of run;(3) Time-weighted average and

highest hourly rolling average CO levelfor each run and for the test;

(4) Highest hourly rolling average HClevel, if HC monitoring is required foreach run and for the test;

(5) If dioxin and furan testing Isrequired under § 266.104(e), time-weighted averge emissions for each runand for the test of chlorinated dioxinand furan emissions, and the predictedmaximum annual average ground levelconcentration of the toxicityequivalency factor;,

(6) Time-weighted average particulatematter emissions for each run and forthe test;

7217=_,, ,




(7) Time-weighted average HCl andC 2 emissions for each run and for thetest;

(8) Time-weighted average emissionsfor the metals subject to regulationunder § 266.106 for each run and for thetest; and

(9) QA/QC results.(iii) Comparison of the actual

emissions during each test with theemissions limits prescribed by§ § 266.104 (b), (c), and (e), 266.105,266.106, and 266.107 and established forthe facility in the certification ofprecompliance under paragraph (b) ofthis section.

(iv) Determination of operating limitsbased on all valid runs of thecompliance test for each applicableparameter listed in paragraph (c)(1) ofthis section using either of the followingprocedures:

(A) Instantaneous limits. A parametermay be measured and recorded on aninstantaneous basis (i.e., the value thatoccurs at any time) and the operatinglimit specified as the time-weightedaverage during all runs of thecompliance test; or

(B) Hourly rolling average basis. (1)The limit for a parameter may beestablished and continuously monitoredon an hourly rolling average basisdefined as follows:

(i) A continuous monitor is one whichcontinuously samples the regulatedparameter without interruption, andevaluates the detector response at leastonce each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(i) An hourly rolling average is thearithmetic mean of the 60 most recent 1-minute average values recorded by thecontinuous monitoring system.

(2) The operating limit for theparameter shall be established based oncompliance test datd as the averageover all test runs of the highest hourlyrolling average value for each run.

(C) Rolling average limits forcarcinogenic metals and lead. Feed ratelimits for the carcinogenic metals (i.e.,arsenic, beryllium, cadmium andchromium) and lead may be establishedeither on an hourly rolling average basisas prescribed by paragraph (c)(4)(iv)(B)of this section or on (up to) a 24 hourrolling average basis. If the owner oroperator elects to use an averagingperiod from 2 to 24 hours:

(1) The feed rate of each metal shallbe limited at any time to ten times thefeed rate that would be allowed on ahourly rolling average basis;

(2) The continuous monitor shall meetthe following specifications:

({I A continuous monitor is one whichcontinuously samples the regulated

parameter without interruption, andevaluates the detector response at leastonce each 15 seconds, and computesand records the average value at leastevery 60 seconds.

(i The rolling average for theselected averaging period is defined asthe arithmetic mean of the most recentone hour block averages for theaveraging period. A one hour blockaverage is the arithmetic mean of theone minute averages recorded during the60-minute period beginning at oneminute after the beginning of precedingclock hour: and

(3] The operating limit for the feedrate of each metal shall be establishedbased on compliance test data as theaverage over all test runs of the highesthourly rolling average feed rate for eachrun.

[D) Feed rate limits for metals, totalchloride and chlorine, and ash. Feedrate limits for metals, total chlorine andchloride, and ash are established andmonitored by knowing the concentrationof the substance (i.e., metals, chloride/chlorine, and ash) in each feedstreamand the flow rate of the feedstream. Tomonitor the feed rate of thesesubstances, the flow rate of eachfeedstream must be monitored under thecontinuous monitoring requirements ofparagraphs (c)(4)(iv) (A) through (C) ofthis section.

(v) Certification of compliancestatement. The following statement shallaccompany the certification ofcompliance:"I certify under penalty of law that this

information was prepared under my directionor supervision in accordance with a systemdesigned to ensure that qualified personnelproperly gathered and evaluated theinformation and supporting documentation.Copies of all emissions tests, dispersionmodeling results and other information usedto determine conformance with therequirements of § 266.103(c) are available atthe facility and can be obtained from the-facility contact person listed above. Based onmy inquiry of the person or persons whomanages the facility, or those personsdirectly responsible for gathering theinformation, the information submitted is, tothe best of my knowledge and belief, true,accurate, and complete. I am aware that thereare significant penalties for submitting falseinformation including the possibility of fineand imprisonment for knowing violations.

I also acknowledge that the operatingconditions established in this certificationpursuant to § 266.103(c)(4)(iv) are enforceablelimits at which the facility can legally operateduring interim status until a revisedcertification of compliance is submitted."

(5) Special requirements for HCmonitoring systems. When an owner oroperator is required to comply with thehydrocarbon (HC) controls provided by§ § 260.104(c) or paragraph (a)(5)(i)(D) of

this section, a conditioned gasmonitoring system may be used inconformance with specificationsprovided in appendix IX of this partprovided that the owner or operatorsubmits a certification of compliancewithout using extensions of timeprovided by paragraph (c)(7) of thissection.

(6) Special operating requirements forindustrialfurnaces that recyclecollected PM Owners and operators ofindustrial furnaces that recycle backinto the furnace particulate matter (PM)from the air pollution control systemmust:

(i) When complying with therequirements of paragraph (c)(3)(ii)(A)of this section, comply with theoperating requirements prescribed in"Alternative Method to Implement theMetals Controls" In appendix IX of thispart; and

(ii) When complying with therequirements of paragraph (c)(3)(ii)(B) ofthis section, comply with the operatingrequirements prescribed by thatparagraph.

(7) Extensions of time. (i) If the owneror operator does not submit a completecertification of compliance for all of theapplicable emissions standards of§ § 266.104, 266.105, 266.106, and 266.107by August 21, 1992. he/she must either:

(A) Stop burning hazardous waste andbegin closure activities under paragraph(1) of this section for the hazardouswaste portion of the facility; or

(B) Limit hazardous waste burning toa total period of 720 hours for the periodof time beginning August 21, 1992,submit a notification to the Director byAugust 21, 1992 stating that the facilityis operating under restricted interimstatus and intends to resume burninghazardous waste, and submit a completecertification of compliance by August 23,1993; or

(C) Obtain a case-by-case extensionof time under paragraph (c}{7)(ii) of thissection.

(ii) The owner or operator mayrequest a case-by-case extension of timeto extend any time limit provided byparagraph (c) of this section ifcompliance with the time limit is notpracticable for reasons beyond thecontrol of the owner or operator.

(A) In granting an extension, theDirector may apply conditions as thefacts warrant to ensure timelycompliance with the requirements of thissection and that the facility operates ina manner that does not pose a hazard tohuman health and the environment;

(B] When an owner and operatorrequest an extension of time to enablethem to obtain a RCRA operating permit



Federal Register J Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations

because the facility cannot meet the HClimit of I 266104c) of this chapter

(1) The Director shall in consideringwhether to grant the extensiom

(43 Determine whether the owner andoperator have submitted in a timelymanner a complete Part B permitapplication that includes informationrequired under § 270.22(b) of thischapter. and

(i) Consider whether the owner andoperator have made a good faith effortto certify compliance with all otheremission controls, including the controlson dioxin, and furans of § 268.104(e)and the controls on PM. metals, andHCI/CI1

(2) If an extension is granted, theDirector shall, as a condition of theextension, require the facility to operateunder flue gas concentration limits onCO and HC that, based on availableinformation, including information in thepart B permit application, are baselineCO and HC levels as defined byI 26.14(f)(1).

(8) Revised certification ofcompliance. The owner or operator maysubmit at any time a revisedcertification of compliance(recertification of compliance) under thefollowing procedures:

(I) Prior to submittal of a revisedcertification of compliance, hazardouswaste may not be burned for more thana total of 720 hours under operatingconditions that exceed those establishedunder a current certification ofcompliance, and such burning may beconducted only for purposes ofdetermining whether the facility canoperate under revised conditions andcontinue to meet the applicableemissions standards of If 266.104,266.105. 2e6.106, and 266.107;

(ii) At least 30 days prior to firstburning hazardous waste underoperating conditions that exceed thoseestablished under a current certificationof compliance, the owner or operatorshall notify the Director and submit thefollowing information:

(A) EPA facility ID number, andfacility name, contact person, telephonenumber, and address;

(B) Operating conditions that theowner or operator is seeking to reviseand description of the changes in facilitydesign or operation that prompted theneed to seek to revise the operatingconditions;

(C) A determination that whenoperating under the revised operatingconditions, the applicable emissionsstandards of §§ 26&104, 260.15, 286.06,and 266.107 are not likely to beexceeded. To document thisdetermination, the owner or operatorshall submit the applicable information

required under paragraph (b)(21 of thissection; and

(D) Complete emissions testingprotocol for any pretesting and for anew compliance test to determinecompliance with the applicableemissions standards of § § 266.104,266.105, 266.106, and 266.107 whenoperating under revised operatingconditions. The protocol shall include aschedule of pre-testing and compliancetesting. If the owner and operatorrevises the scheduled date for thecompliance test, hejshe shall notify theDirector in writing at least 30 days priorto the revised date of the compliancetest;

(iii) Conduct a compliance test underthe revised operating conditions and theprotocol submitted to the Director todetermine compliance with theapplicable emissions standards of§ § 266.104, 266.105, 266.106, and 286.107;and

(iv) Submit a revised certification ofcompliance under paragraph (c)(4) ofthis section.

(d) Periodic Recertifications. Theowner or operator must conductcompliance testing and submit to theDirector a recertification of complianceunder provisions of paragraph Cc) of thissection within three years fromsubmitting the previous certification orrecertification. If the owner or operatorseeks to recertify compliance under newoperating conditions, he/she mustcomply with the requirements ofparagraph (c)(8) of this section.

(e) Noncompliance with certificationschedule. If the owner or operator doesnot comply with the interim statuscompliance schedule provided byparagraphs (b), (c), and (d) of thissection, hazardous waste burning mustterminate on the date that the deadlineis missed, closure activities must beginunder paragraph (I) of this section, andhazardous waste burning may notresume except under an operatingpermit issued under § 270.66 of thischapter.

(f) Start-up and shut-down. Hazardouswaste (except waste fed solely as aningredient under the Tier I (or adjustedTier I) feed rate screening limits formetals and chloride/chlorine) must notbe fed into the device during start-upand shut-down of the boiler or industrialfurnace, unless the device is operatingwithin the conditions of operationspecified in the certification ofcompliance.

(g) Automatic waste feed cutoff.During the compliance test required byparagraph (cXs) of this section, andupon certification of compliance underparagraph (c) of this section, a boiler orindustrial furnace must be operated with

a functioning system that automaticallycuts off the hazardous waste feed whenthe applicable operating conditionsspecified in paragraphs (c)(l) (i) and (vthrough xiii) of this section deviate fromthose established in the certification ofcompliance. In addition:

(1) To minimize emissions or organiccompounds, the minimum combustionchamber temperature (or the indicator ofcombustion chamber temperature) thatoccurred during the compliance testmust be maintained while hazardouswaste or hazardous waste residuesremain in the combustion chamber, withthe minimum temperature during thecompliance test defined as either.

(i) If compliance with the combustionchamber temperature limit Is based on ahourly rolling average, the minimumtemperature during the compliance testis considered to be the average over allruns of the lowest hourly rolling averagefor each run; or

(ii If compliance with the combustionchamber temperature limit is based onan instantaneous temperaturemeasurement, the minimum temperatureduring the compliance test is consideredto be the time-weighted averagetemperature during all runs of the test;and

(2) Operating parameters limited bythe certification of compliance mustcontinue to be monitored during thecutoff, and the hazardous waste feedshall not be restarted until the levels ofthose parameters comply with the limitsestablished in the certification ofcompliance.

(h) Fugitive emissions. Fugitiveemissions must be controlled by:

(1) Keeping the combustion zonetotally sealed against fugitive emissions;or

(2) Maintaining the combustion zonepressure lower than atmosphericpressure; or

(3) An alternate means of control thatthe owner or operator can demonstrateprovide fugitive emissions controlequivalent to maintenance ofcombustion zone pressure lower thanatmospheric pressure. Support for suchdemonstration shall be included in theoperating record.

(i) Changes. A boiler or industrialfurnace must cease burning hazardouswaste when changes in combustionproperties, or feed rates of thehazardous waste, other fuels, orindustrial furnace feedstocks, orchanges In the boiler or industrialfurnace design or operating conditionsdeviate from the limits specified in thecertification of compliance.

(1 Monitoring and Inspections. (1) Theowner or operator must monitor and

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7220 Federal Register / Vol. 56, No. '35 / Thursday, February 21, 1991 / Rules and Regulations'

record the following, at a minimum,while burning hazardous waste:

(i) Feed rates and composition ofhazardous waste, other fuels, andindustrial furnace feed stocks, and feedrates of ash, metals, and total chlorideand chlorine as necessary to ensureconformance with the certification ofprecompliance or certification ofcompliance;

( [ii) Carbon monoxide (CO), oxygen,and if applicable, hydrocarbons (HC), ona continuous basis at a common point inthe boiler or industrial furnacedownstream of the combustion zone andprior to release of stack gases to theatmosphere in accordance with theoperating limits specified in thecertification of compliance. CO, HC, andoxygen monitors must be installed,operated, and maintained in accordancewith methods specified in Appendix IXof this part.

(iii) Upon the request of the Director,sampling and analysis of the hazardouswaste (and other fuels and industrialfurnace feed stocks as appropriate) andthe stack gas emissions must beconducted to verify that the operatingconditions established in thecertification of precompliance orcertification of compliance achieve theapplicable standards of § § 268.104,266.105, 266.106, and 266.107.

(2) The boiler or industrial furnaceand associated equipment (pumps,valves, pipes, fuel storage tanks, etc.)must be subjected to thorough visualinspection when they contain hazardouswaste, at least daily for leaks, spills,fugitive emissions, and signs oftampering.

(3) The automatic hazardous wastefeed cutoff system and associatedalarms must be tested at least onceevery 7 days when hazardous waste isburned to verify operability, unless theowner or operator can demonstrate thatweekly inspections will unduly restrictor upset operations and that lessfrequent inspections will be adequate.Support for such demonstration shall beincluded in the operating record. At aminimum, operational testing must beconducted at least once every 30 days.

(4) These monitoring and inspectiondata must be recorded and the recordsmust be placed in the operating log.

(k) Recordkeeping. The owner oroperator must keep in the operatingrecord of the facility all information anddata required by this section for aperiod of three years.

(1) Closure. At closure, the owner oroperator must remove all hazardouswaste and hazardous waste residues(including, but not limited to, ash,scrubber waters, and scrubber sludges)from the boiler or industrial furnace and

must comply with § § 265.111-265.115 ofthis chapter.(Approved by the Office of Management andBudget under control number 2050-0073)

§ 266.104 Standards to control organicemissions.

(a) DRE standard-{1) General.Except as provided in paragraph (a)(3)of this section, a boiler or industrialfurnace burning hazardous waste mustachieve a destruction and removalefficiency (DRE) of 99.99% for all organichazardous constituents in the wastefeed. To demonstrate conformance withthis requirement, 99.99% DRE must bedemonstrated during a trial burn foreach principal organic hazardousconstituent (POHC) designated (underparagraph (a)(2) of this section) in itspermit for each waste feed. DRE isdetermined for each POHC from thefollowing equation:

DRE -- [ 1xlooWn

where:W ,,= Mass feed rate of one principal

organic hazardous constituent (POHC) inthe hazardous waste fired to the boiler orindustrial furnace; and

•Wo.t= Mass emission rate of the samePOHC present in stack gas prior torelease to the atmosphere.

(21 Designation of POHCs. Principalorganic hazardous constituents (POHCs)are those compounds for whichcompliance with the DRE requirementsof this section shall be demonstrated in -a trial burn in conformance withprocedures prescribed in § 270.66 of thischapter. One or more POHCs shall bedesignated by the Director for eachwaste feed to be burned. POHCs shallbe designated based on the degree ofdifficulty of destruction of the organicconstituents in the waste and on theirconcentrations or mass in the wastefeed considering the results of wasteanalyses submitted with part B of thepermit application. POHCs are mostlikely to be selected from among thosecompounds listed in part 261, appendixVIII of this chapter that are also presentin the normalwaste feed. However, ifthe applicant demonstrates to theRegional Administrator's satisfactionthat a compound not listed in appendixVIII or not present in the normal wastefeed is a suitable indicator ofcompliance with the DRE requirementsof this section, that compound may bedesignated as a POHC. Such POHCsneed not be toxic or organic compounds.

. (3) Dioxin-listed waste. A boiler orindustrial furnace burning hazardouswaste containing (or derived from) EPAHazardous Wastes Nos. F020, F021,F022, F023, F026, or F027 must achieve adestruction and removal efficiency(DRE) of 99.9999% for each POHCdesignated (under paragraph (a)(2) ofthis section) in its permit. Thisperformance must be demonstrated onPOHCs that are more difficult to burnthan tetrra-, penta-, andhexachlorodibenzo-p-dioxins anddibenzofurans. DRE is determined foreach POHC from the equation inparagraph (a) of this section. In addition,the owner or operator of the boiler orindustrial furnace must notify theDirector of intent to burn EPAHazardous Waste Nos. F020, F021, F022,F023, F026, or F027.

(4) Automatic waiver of DRE trialburn. Owners and operators of boilersoperated under the special operatingrequirements provided by § 266.110 areconsidered to be in compliance with theDRE standard of paragraph (a)(1) of thissection and are exempt from the DREtrial burn.

(5) Low risk waste. Owners andoperators of boilers or industrialfurnaces that burn hazardous waste incompliance with the requirements of§ 268.109(a) are considered to be incompliance with the DRE standard ofparagraph (a)(1) of this section and areexempt from the DRE trial burn.

(b) Carbon monoxide standard. (1)Except as provided in paragraph (c) ofthis section, the stack gas concentrationof carbon monoxide (CO) from a boileror industrial furnace burning hazardouswaste cannot exceed 100 ppmv on anhourly rolling average basis (i.e., overany 60 minute period), continuouslycorrected to 7 percent oxygen, dry gasbasis.

(2) CO and oxygen shall becontinuously monitored in conformancewith "Performance Specifications forContinuous Emission Monitoring ofCarbon Monoxide andOxygen inHazardous Waste Incinerators, Boilers,and Industrial Furnaces" in appendix IXof this part.

(3) Compliance with the 100 ppmv COlimit must be demonstrated during thetrial burn (for new facilities or aninterim status facility applying for apermit) or the compliance test (forinterim status facilities). To demonstratecompliance, the highest hourly rollingaverage CO level during any valid run ofthe trial burn or compliance test mustnot exceed 100 ppmv.

(c) Alternative carbon monoxidestandard. (1) The stack gasconcentration of carbon monoxide (CO)



Federal Register I Vol. 5% No. 35 / Thursday, February 21, 1991 / Rules and Regulations

from a boiler or industrial furnaceburning hazardous waste may exceedthe 100 ppmv limit provided that stackgas concentrations of hydrocarbons(HC) do not exceed 20 ppmv, except asprovided by paragraph (f) of this sectionfor certain industrial furnaces.

(2) HC limits must be establishedunder this section on an hourly rollingaverage basis (i.e., over any 60 minuteperiod), reported as propane, andcontinuously corrected to 7 percentoxygen, dry gas basis.

(3) HC shall be continuouslymonitored in conformance with"Performance Specifications forContinuous Emission Monitoring ofHydrocarbons for Incinerators, Boilers,and Industrial Furnaces" in appendix IXof this part. CO oxygen shall becontinuously monitored in conformancewith paragraph (b)(2) of this section.

(4) The alternative CO standard isestablished based on CO data duringthe trial burn (for a new facility) and thecompliance test (for an interim statusfacility). The alternative CO standard isthe average over all valid runs of thehighest hourly average CO level for eachrun. The CO limit is implemented on anhourly rolling average basis, andcontinuously corrected to 7 percentoxygen, dry gas basis.

(d) Special requirements forfurnaces.Owners and operators of industrialfurnaces (e.g., kilns, cupolas) that feedhazardous waste for a purpose otherthan solely as an ingredient (see§ 266.103(a)(5)(ii)) at any location otherthan the end where products arenormally discharged and where fuelsare normally fired must comply with thehydrocarbon limits provided byparagraphs (c) or (f) of this sectionirrespective of whether stack gas COconcentrations meet the 100 ppmv limitof paragraph (b) of this section.

(e) Controls for dioxins and furans.Owners and operators of boilers andindustrial furnaces that are equippedwith a dry particulate matter controldevice that operates within thetemperature range of 450-750 °F, andindustrial furnaces operating under analternative hydrocarbon limitestablished under paragraph (f) of thissection must conduct a site-specific riskassessment as follows to demonstratethat emissions of chlorinated dibenzo-p-dioxins and dibenzofurans do not resultin an increased lifetime cancer risk tothe hypothetical maximum exposedindividual (MEl) exceeding I in 100,000:

(1) During the trial burn (for newfacilities or an interim status facilityapplying for a permit) or compliance test(for interim status facilities), determineemission rates of the tetra-octacongeners of chlorinated dibenzo-p-

dioxins and dibenzofurans (CDDs/CDFs) using Method 23, "Determinationof Polychlorinated Dibenzo-p-Dioxinsand Polychlorinated Dibenzofurans(PCDFs) from Stationary Sources", inappendix IX of this part.

(2) Estimate the 2,3,7,8-TCDD toxicityequivalence of the tetra-octa CDDs/CDFs congeners using "Procedures forEstimating the Toxicity Equivalence ofChlorinated Dibenzo-p-Dioxin andDibenzofuran Congeners" in appendixIX of this part. Multiply the emissionrates of CDD/CDF congeners with atoxicity equivalence greater than zero(see the procedure) by the calculatedtoxicity equivalence factor to estimatethe equivalent emission rate of 2,3,7,8-TCDD.

(3) Conduct dispersion modeling usingmethods recommended in Guideline onAir Quality Models (Revised] or the"Hazardous Waste Combustion AirQuality Screening Procedure", which areprovided in appendices X and IX,respectively, of this part, or "EPASCREEN Screening Procedure" asdescribed in Screening Procedures forEstimating Air Quality Impact ofStationary Sources (incorporated byreference in 1260.11) to predict themaximum annual average off-siteground level concentration of 2,3,7,8-TCDD equivalents determined underparagraph (e)(2) of this section. Themaximum annual average on-siteconcentration must be used when aperson resides on-site; and

(4) The ratio of the predictedmaximum annual average ground levelconcentration of 2,3,7,8-TCDDequivalents to the risk-specific dose for2,3,7,8-TCDD provided in appendix V ofthis part 2.2 X 10- 7) shall not exceed 1.0.

(f) Alternative HC limit forfurnaceswith organic matter in raw material. Forindustrial furnaces that cannot meet the20 ppmv HC limit because of organicmatter in normal raw material, theDirector may establish an alternativeHC limit on a case-by-case basis (undera part B permit proceeding) at a levelthat ensures that flue gas HC (and CO)concentrations when burning hazardouswaste are not greater than when notburning hazardous waste (the baselineHC level) provided that the owner oroperator complies with the followingrequirements. However, cement kilnsequipped with a by-pass duct meetingthe requirements of paragraph (g) of thissection, are not eligible for analternative HC limit.

(1) The owner or operator mustdemonstrate that the facility is designedand operated to minimize hydrocarbonemissions from fuels and raw materialswhen the baseline HC (and 00) level isdetermined. The baseline HC (and CO)

level is defined as the average over allvalid test runs of the highest hourlyrolling average value for each run whenthe facility does not burn hazardouswaste, and produces normal productsunder normal operating conditionsfeeding normal feedstocks and fuels.More than one baseline level may bedetermined if the facility operates underdifferent modes that may generatesignificantly different HC (and CO)levels;

(2) The owner or operator mustdevelop an approach to monitor overtime changes in the operation of thefacility that could reduce the baselineHC level;

(3) The owner or operator mustconduct emissions testing during thetrial burn to:

(Ci Determine the baseline HC (andCO) level;

(ii) Demonstrate that, when hazardouswaste is burned, HC (and CO) levels donot exceed the baseline level; and

(iii) Identify the types andconcentrations of organic compoundslisted in appendix VIII, part 261 of thischapter, that are emitted and conductsdispersion modeling to predict themaximum annual average ground levelconcentration of each organiccompound. On-site ground levelconcentrations must be considered forthis evaluation if a person resides onsite.

(A) Sampling and analysis of organicemissions shall be conducted usingprocedures prescribed by the Director.

[B) Dispersion modeling shall beconducted according to proceduresprovided by paragraph (e)(2) of thissection; and

(iv) Demonstrate that maximumannual average ground levelconcentrations of the organiccompounds identified in paragraph(f)(3)(iii) of this section do not exceedthe following levels:

(A) For the noncarcinogeniccompounds listed in appendix IV of thispart, the levels established in appendixIV;

(B) For the carcinogenic compoundslisted in appendix V of this part, the sumfor all compounds of the ratios of theactual ground level concentration to thelevel established in appendix V cannotexceed 1.0. To estimate the health riskfrom chlorinated dibenzo-p-dioxins anddibenzofuran congeners, use theprocedures prescribed by paragraph(e)(3) of this section to estimate the2,3,7,8-TCDD toxicity equivalence of thecongeners.

(C) For compounds not listed Inappendix IV or V, 0.1 micrograms percubic meter.

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7222 Federal Register / Vol. 56, No. 35 / Thursday, February 21. 1991 / Rules and Regulations

(4) All hydrocarbon levels specifiedunder this paragraph are to bemonitored and reported as specified inparagraphs (c)(1) and (c)(2) of thissection.

(g) Monitoring CO and HC in the by-pass duct of a cement kiln. Cement kilnsmay comply with the carbon monoxideand hydrocarbon limits provided byparagraphs (b), (c), and (d) of thissection by monitoring in the by-passduct provided that:

(1) Hazardous waste is fired only Intothe kiln and not at any locationdownstream from the kiln exit relativeto the direction of gas flow; and

2. The by-pass duct diverts aminimum of 10% of kiln off-gas into theduct.

(h) Use of emissions test data todemonstrate compliance and establishoperating limits. Compliance with therequirements of this section must bedemonstrated simultaneously byemissions testing or during separateruns under identical operatingconditions. Further, data to demonstratecompliance with the CO and HC limitsof this section or to establish alternativeCO or HC limits under this section mustbe obtained during the time that DREtesting, and where applicable, CDD/CDF testing under paragraph (e) of thissection and comprehensive organicemissions testing under paragraph (f) isconducted.

(i) Enforcement For the purposes ofpermit enforcement, compliance withthe operating requirements specified inthe permit (under § 266.102) will beregarded as compliance with thissection. However, evidence thatcompliance with those permit conditionsis insufficient to ensure compliance withthe requirements of this section may be"information" justifying modification orrevocation and re-issuance of a permitunder § 270.41 of this chapter.

§ 266.105 Standards to control particulatematter.

(a) A boiler or industrial furnaceburning hazardous waste may not emitparticulate matter in excess of 180milligrams per dry standard cubic meter(0.08 grains per dry standard cubic foot)after correction to a stack gasconcentration of 7% oxygen, usingprocedures prescribed in 40 CFR part 60,appendix A, methods 1 through 5, andappendix IX of this part.

(b) An owner or operator meeting therequirements of § 266.109(b) for the lowrisk waste exemption is exempt from theparticulate matter standard.

(c) For the purposes of permitenforcement, compliance with theoperating requirements specified in thepermit (under § 266.102) will be regarded

as compliance with this section.However, evidence that compliancewith those permit conditions isinsufficient to ensure compliance withthe requirements of this section may be"information" justifying modification orrevocation and re-issuance of a permitunder § 270.41 of this chapter.

§ 266.106 Standards to control metalsemissions.

(a) General. The owner or operatormust comply with the metals standardsprovided by paragraphs (b), (c), (d), (e),or (f) of this section for each metal listedin paragraph (b) of this section that ispresent in the hazardous waste atdetectable levels using analyticalprocedures specified in Test Methodsfor Evaluation Solid Waste, Physical/Chemical Methods (SW--846).incorporated by reference in § 260.11 ofthis chapter.

(b) Tier Ifeed rate screening limits.Feed rate screening limits for metals arespecified in appendix I of this part as afunction of terrain-adjusted effectivestack height and terrain and land use inthe vicinity of the facility. Criteria forfacilities that are not eligible to complywith the screening limits are provided inparagraph (b)(7) of this section.

(1) Noncarcinogenic metals. The feedrates of antimony, barium, lead,mercury, thallium, and silver in all feedstreams, including hazardous waste,fuels, and industrial furnace feed stocksshall not exceed the screening limitsspecified in appendix I of this part.

(i) The feed rate screening limits forantimony, barium, mercury, thallium,and silver are based on either

(A) An hourly rolling average asdefined in § 266.102(e)(6](i)(B); or

(B) An instantaneous limit not to beexceeded at any time.

(ii) The feed rate screening limit forlead is based on one of the following:

(A) An hourly rolling average asdefined in § 266.102(e)(6)(i)(B);

(B) An averaging period of 2 to 24hours as defined in § 266.102(e)(6)(ii)with an instantaneous feed rate limit notto exceed 10 times the feed rate thatwould be allowed on an hourly rollingaverage basis; or

(C) An instantaneous limit not to beexceeded at any time.

(2) Carcinogenic metals. (I) The feedrates of arsenic, cadmium, beryllium,and chromium in all feed streams,including hazardous waste, fuels, andindustrial furnace feed stocks shall notexceed values derived from thescreening limits specified in appendix Iof this part. The feed rate of each ofthese metals is limited to a level suchthat the sum of the ratios of the actualfeed rate to the feed rate screening limit

specified in appendix I shall not exceed1.0, as provided by the followingequation:

AFRo

FRSLW

where:n=numer of carcinogenic metalsAFR=actual feed rate to the device for

metal "i"FRSL= feed rate screening limit provided

by appendix I of this part for metal "I".

(ii) The feed rate screening limits forthe carcinogenic metals are based oneither:

(A) An hourly rolling average; or(B) An averaging period of 2 to 24

hours with an instantaneous feed ratelimit not to exceed 10 times the feed ratethat would be allowed on an hourlyrolling average basis.

(3) TESH. (i) The terrain-adjustedeffective stack height is determinedaccording to the following equation:

TESH=Ha+HI-Tr

where:Ha=Actual physical stack heightHi = Plume rise as determined from

appendix VI of this part as a function ofstack flow rate and stack gas exhausttemperature.

Tr=Terrain rise within five kilometers ofthe stack.

(ii) The stack height (Ha) may notexceed good engineering practice asspecified in 40 CFR 51.100(ii).

(iii) If the TESH for a particularfacility is not listed in the table in theappendices, the nearest lower TESHlisted in the table shall be used. If theTESH is four meters or less, a value offour meters shall be used.

(4) Terrain type. The screening limitsare a function of whether the facility islocated in noncomplex or complexterrain. A device located where any.partof the surrounding terrain within 5kilometers of the stack equals orexceeds the elevation of the physicalstack height (Ha) is considered to be incomplex terrain and the screening limitsfor complex terrain apply. Terrainmeasurements are to be made from U.S.Geological Survey 7.5-minutetopographic maps of the areasurrounding the facility.

•{5) Land use. The screening limits area function of whether the facility islocated in an area where the land use isurban or rural. To determine whetherland use in the vicinity of the facility isurban or rural, procedures provided inappendices IX or X of this part.




(6) Multiple stacks. Owners andoperators of facilities with more thanone on-site stack from a boiler,industrial furnace, incinerator, or otherthermal treatment unit subject tocontrols of metals emissions under aRCRA operating permit or interim statuscontrols must comply with the screeninglimits for all such units assuming allhazardous waste is fed into the devicewith the worst-case stack based ondispersion characteristics. The worst-case stack is determined from thefollowing equation as applied to eachstack:

K=HVTWhere:

K =a parameter accounting for relativeinfluence of stack height and plume rise;

K=physical stack height (meters);K= stack gas flow rate (m3/second); andT=exhaust temperature (°K).

The stack with the lowest value of K isthe worst-case stack.

(7) Criteria for facilities not eligiblefor screening limits. If any criteriabelow are met, the Tier I (and Tier II)screening limits do not apply. Ownersand operators of such facilities mustcomply with the Tier III standardsprovided by paragraph (d) of thissection.

(i) The device is located in a narrowvalley less than one kilometer wide;

(ii) The device has a stack taller than20 meters and is located such that theterrain rises to the physical heightwithin one kilometer of the facility;

(iii) The device has a stack taller than20 meters and is located within fivekilometers of a shoreline of a large bodyof water such as an ocean or large lake;

(iv) The physical stack height of anystack is less than 2.5 times the height ofany building within five building heightsor five projected building widths of thestack and the distance from the stack tothe closest boundary is within fivebuilding heights or five projectedbuilding widths of the associatedbuilding; or

(v) The Director determines thatstandards based on site-specificdispersion modeling are required.

(8) Implementation. The feed rate ofmetals in each feedstream must bemonitored to ensure that the feed ratescreening limits are not exceeded.

(c) Tier II emission rate screeninglimits. Emission rate screening limits arespecified in Appendix I as a function ofterrain-adjusted effective stack heightand terrain and land use in the vicinityof the facility. Criteria for facilities thatare not eligible to comply with thescreening limits are provided inparagraph (b)(7) of this section.

(1) Noncarcinogenic metals. Theemission rates of antimony, barium,

lead, mercury, thallium, and silver shallnot exceed the screening limits specifiedin Appendix I of this part.

(2) Carcinogenic metals. The emissionrates of arsenic, cadmium, beryllium,and chromium shall not exceed valuesderived from the screening limitsspecified in Appendix I of this part. Theemission rate of each of these metals islimited to a level such that the sum ofthe ratios of the actual emission rate tothe emission rate screening limitspecified in Appendix I shall not exceed1.0, as provided by the followingequation:

nAER )- <51.0

1=1 ERSL(0

where:n =number of carcinogenic metalsAER= actual emission rate for metal "i"ERSL=emission rate screening limit

provided by appendix I of this part formetal "i'.

(3) Implementation. The emission ratelimits must be implemented by limitingfeed rates of the individual metals tolevels during the trial burn (for newfacilities or an interim status facilityapplying for a permit) or the compliancetest (for interim status facilities). Thefeed rate averaging periods are the sameas provided by paragraphs (b)(1)(i) and(ii) and (b)(2)(ii) of this section. The feedrate of metals in each feedstream mustbe monitored to ensure that the feed ratelimits for the feedstreams specifiedunder § § 266.102 or 266.103 are notexceeded.

(4) Definitions and limitations. Thedefinitions and limitations provided byparagraph (b) of this section for thefollowing terms also apply to the Tier IIemission rate screening limits providedby paragraph (c) of this section: terrain-adjusted effective stack height, goodengineering practice stack height, terraintype, land use, and criteria for facilitiesnot eligible to use the screening limits.

(5) Multiple stacks. (i) Owners andoperators of facilities with more thanone onsite stack from a boiler, industrialfurnace, incinerator, or other thermaltreatment unit subject to controls onmetals emissions under a RCRAoperating permit or interim statuscontrols must comply with the emissionsscreening limits for any such stacksassuming all hazardous waste is fed intothe device with the worst-case stackbased on dispersion characteristics.

(ii) The worst-case stack isdetermined by procedures provided inparagraph (b)(6) of this section.

(iii) For each metal, the totalemissions of the metal from those stacks

shall not exceed the screening limit forthe worst-case stack.

(d) Tier III site-specific riskassessment-{I) General. Conformancewith the Tier III metals controls must bedemonstrated by emissions testing todetermine the emission rate for eachmetal, air dispersion modeling to predictthe maximum annual average off-siteground level concentration for eachmetal, and a demonstration thatacceptable ambient levels are notexceeded.

(2) Acceptable ambient levels.Appendices IV and V of this part list theacceptable ambient levels for purposesof this rule. Reference air concentrations(RACs) are listed for thenoncarcinogenic metals and 10-5 risk-specific doses (RSDs) are listed for thecarcinogenic metals. The RSD for ametal is the acceptable ambient level forthat metal provided that only one of thefour carcinogenic metals is emitted. Ifmore than one carcinogenic metal isemitted, the acceptable ambient levelfor the carcinogenic metals is a fractionof the RSD as described in paragraph(d)(3) of this section.

(3) Carcinogenic metals. For thecarcinogenic metals, arsenic, cadmium,beryllium, and chromium, the sum of theratios of the predicted maximum annualaverage off-site ground levelconcentrations (except that on-siteconcentrations must be considered if aperson resides on site) to the risk-specific dose (RSD) for all carcinogenicmetals emitted shall not exceed 1.0 asdetermined by the following equation:

Predicted AmbientConcentrations) :51.0

i=1 Risk-Specific Dosew

where: n=number of carcinogenic metals

(4) Noncarcinogenic metals. For thenoncarcinogenic metals, the predictedmaximum annual average off-siteground level concentration for eachmetal shall not exceed the reference airconcentration (RAC).

(5) Multiple stacks. Owners andoperators of facilities with more thanone on-site stack from a boiler,industrial furnace, incinerator, or otherthermal treatment unit subject tocontrols on metals emissions under aRCRA operating permit or interim statuscontrols must conduct emissions testingand dispersion modeling to demonstratethat the aggregate emissions from allsuch on-site stacks do not result in anexceedance of the acceptable ambientlevels:

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(6) Implementation. Under Tier III, themetals controls must be implemented bylimiting feed rates of the individualmetals to levels during the trial burn (fornew facilities or an interim statusfacility applying for a permit) or thecompliance test (for interim statusfacilities). The feed rate averagingperiods are the same as provided byparagraphs (b)(1) (i) and (ii) and[b)(2)(ii) of this section. The feed rate ofmetals in each feedstream must bemonitored to ensure that the feed ratelimits for the feedstreams specifiedunder § § 266.102 or 266.103 are notexceeded.

(e) Adjusted Tier I feed rate screeninglimits. The owner or operator mayadjust the feed rate screening limitsprovided by appendix I of this part toaccount for site-specific dispersionmodeling. Under this approach, theadjusted feed rate screening limit foreach metal is determined by back-calculating from the acceptable ambientlevels provided by appendices IV and Vof this part using dispersion modeling todetermine the maximum allowableemission rate. This emission ratebecomes the adjusted Tier I feed ratescreening limit. The feed rate screeninglimits for carcinogenic metals areimplemented as prescribed in paragraph(b)(2) of this section.

(f) Alternative implementationapproaches. (1) The Director mayapprove on a case-by-case basisapproaches to implement the Tier II orTier III metals emission limits providedby paragraphs (c) or (d) of this sectionalternative to monitoring the feed rate ofmetals in each feedstream.

(2) The emission limits provided byparagraph (d) of this section must bedetermined as follows:

(i) For each noncarcinogenic metal, byback-calculating from the RAC providedin appendix IV of this part to determinethe allowable emission rate for eachmetal using the dilution factor for themaximum annual average ground levelconcentration predicted by dispersionmodeling in conformance withparagraph (h) of this section; and

(ii) For each carcinogenic metal; by:(A) Back-calculating from the RSD

provided in appendix V of this part todetermine the allowable emission ratefor each metal if that metal were theonly carcinogenic metal emitted usingthe dilution factor for the maximumannual average ground levelconcentration predicted by dispersionmodeling in conformance withparagraph (h) of this section; and

(B) If more than one carcinogenicmetal is emitted, selecting an emission.limit for each carcinogenic metal not toexceed the emission rate determined by

paragraph (f)(2)(ii)(A) of this sectionsuch that the sum for all carcinogenicmetals of the ratio of the selectedemission limit to the emission ratedetermined by that paragraph does notexceed 1.0.

(g) Emission testing-(1) General.Emission testing for metals shall beconducted using the Multiple MetalsTrain as described in appendix IX ofthis part.

(2) Hexavalent chromium. Emissionsof chromium are assumed to behexavalent chromium unless the owneror operator conducts emissions testingto determine hexavalent chromiumemissions using procedures prescribedin Appendix IX of this part.

(h) Dispersion modeling. Dispersionmodeling required under this sectionshall be conducted according tomethods recommended in appendix X ofthis part, the "Hazardous WasteCombustion Air Quality ScreeningProcedure" described in appendix IX ofthis part, or "EPA SCREEN ScreeningProcedure" as described in ScreeningProcedures for Estimating Air QualityImpact of Stationary Sources (the latterdocument is incorporated by reference,see § 260.11) to predict the maximumannual average off-site ground levelconcentration. However, on-siteconcentrations must be consideredwhen a person resides on-site.

(I) EnforcemenL For the purposes ofpermit enforcement, compliance withthe operating requirements specified inthe permit (under § 266.102) will beregarded as compliance with thissection. However, evidence thatcompliance with those permit conditionsis insufficient to ensure compliance withthe requirements of this section may be"information" justifying modification orrevocation and re-issuance of a permitunder § 270.41 of this chapter.

§ 266.107 Standards to control hydrogenchloride (HCI) and chlorine gas (C%2)emissions.

(a) General. The owner or operatormust comply with the hydrogen chloride(HCI) and chlorine (C2) controlsprovided by paragraphs (b), (c), or (d) ofthis section.

(b) Screening limits--(1) Tier Ifeedrate screenizg limits. Feed ratescreening limits are specified for totalchlorine in Appendix I of this part as afunction of terrain-adjusted effectivestack height and terrain and land use inthe vicinity of the facility. The feed rateof total chlorine and chloride, bothorganic and inorganic, in all feedstreams, including hazardous waste,fuels, and industrial furnace feed stocksshall not exceed the levels specified.

(2) Tier II emission rate screen limits.Emission rate screening limits for HCIand C6i are speoified in Appendix III ofthis part as a function of terrain-adjusted effective stack height andterrain and land use in the vicinity of thefacility. The stack emission rates of HCIand Cl shall not exceed the levelsspecified.

(3) Definitions and limitations. Thedefinitions and limitations provided by§ 266.106(b) for the following terms alsoapply to the screening limits providedby this paragraph: terrain-adjustedeffective stack height, good engineeringpractice stack height, terrain type, landuse, and criteria for facilities not eligibleto use the screen limits.

(4) Multiple stacks. Owners andoperators of facilities with more thanone on-site stack from a boiler,industrial furnace, incinerator, or otherthermal treatment unit subject tocontrols on HCI or C6i emissions under aRCRA operating permit or interim statuscontrols must comply with the Tier I andTier II screening limits for those stacksassuming all hazardous waste is fed intothe device with the worst-case stackbased on dispersion characteristics.

(i) The worst-case stack is determinedby procedures provided in§ 266.106(b)(6).

(ii) Under Tier I, the total feed rate ofchlorine and chloride to all subjectdevices shall not exceed the screeninglimit for the worst-case stack.

(iii) Under Tier II, the total emissionsof HCI and C1 from all subject stacksshall not exceed the screening limit forthe Worst-case stack.

(c) Tier III site-specific riskassessments-(1) General. Conformancewith the Tier III controls must bedemonstrated by emissions testing todetermine the emission rate for HCI andC12, air dispersion modeling to predictthe maximum annual average off-siteground level concentration for eachcompound, and a demonstration thatacceptable ambient levels are notexceeded.

(2) Acceptable ambient levels.Appendix IV of this part lists thereference air concentrations (RACs) forHCI (7 micrograms per cubic meter) andCli (0.4 micrograms per cubic meter).

(3) Multiple stacks. Owners andoperators of facilities with more thanone on-site stack from a boiler,industrial furnace, incinerator, or otherthermal treatment unit subject tocontrols on HCI or C12 emissions under aRCRA operating permit or interim statuscontrols must conduct emissions testingand dispersion modeling to demonstratethat the aggregate emissions from allsuch on-site stacks do not result in an




exceedance of the acceptable ambientlevels for HCI and Cls.

(d) A veraging periods. The HCl andCl6 controls are implemented by limitingthe feed rate of total chlorine andchloride in all feedstreams, includinghazardous waste, fuels, and industrialfurnace feed stocks. Under Tier , thefeed rate of total chloride and chlorine islimited to the Tier I Screening Limits.Under Tier II and Tier 1L the feed rateof total chloride and chlorine is limitedto the feed rates during the trial bum(for new facilities or an interim statusfacility applying for a permit) or thecompliance test (for interim statusfacilities). The feed rate limits are basedon either:

(i) An hourly rolling average asdefined in § 266.102(e)(6); or

(ii) AnA instantaneous basis not to beexceeded at any time.

(e) Adjusted Tier Ifeed rate screeninglimits. The owner or operator mayadjust the feed rate screening providedby Appendix I of this part to account forsite-specific dispersion modeling. Underthis approach, the adjusted feed ratescreening limit is determined by back-calculating from the acceptable ambientlevel for C12 provided by Appendix IV ofthis part using dispersion modeling todetermine the maximum allowableemission rate. This emission ratebecomes the adjusted Tier I feed ratescreening limit.

(f) Emissions testing. Emissionstesting for HCI and Ch shall beconducted using the proceduresdescribed in Appendix IX of this part

(g) Dispersion modeling. Dispersionmodeling shall be conducted accordingto the provisions of § 266.106(h).

(h) Enforcement. For the purposes ofpermit enforcement, compliance withthe operating requirements specified inthe permit (under § 266.102) will beregarded as compliance with his section.However, evidence that compliancewith those permit conditions Isinsufficient to ensure compliance withthe requirements of this section may be"information" justifying modification orrevocation and re-issuance of a permitunder § 270.41 of this chapter.

§ 266.108 Small quantity on-alte burnerexemption.

(a) Exemption quantities. Owners andoperators of facilities that burnhazardous waste in an on-site boiler orindustrial furnace are exempt from therequirements of this section providedthat:

(1) The quantity of hazardous wasteburned in a device for a calendar monthdoes not exceed the limits provided inthe following table based on the terrain-adjusted effective stack height as

defined in § 266.106(b)(3):

EXEMPT QUANTITIES FOR SMALLQUANTITY BURNER EXEMPTION

Allow- Allow-able able

Terrain- hazard- Terrain- hazard-adjusted os adjusted ous

effective stack waste effective stack wasteheight of burning height of buming

device rate device rate(meters) (gal- (meters) (Gal-

Ions/ lonslmonth) month)

0 to 3.9 ............. 0 40.0 to 44.9 2104.0 to 5.9 .......... 13 45.0 to 49.9 2606.0 to 7.9 ........... 18 50.0 to 54.9 3308.0 to 9.9 .......... 27 55.0 to 59.9 40010.011.9 .......... 40 60.0 to 64.9..... 49012.0 to 13.9 ....... 48 65.0 to 69.9 61014.0 to 15.9 59 70.0 to 74.9 ....... 68016.0 to 17.9..-- 69 75.0 to 79.9..... 76018.0 to 19.9 76 80.0 to 84.9 ...... 85020.0 to 21.9 84 85.0 to 89.9 96022.0 to 23.9 93 90.0 to 94.9 1,10024.0 to 25.9..... 100 95.0 to 99.9 1,20026.0 to 27.9 110 100.0 to 104.9.. 1.30028.0 to 29.9 ....... 130 105.0 to 109.9.. 1,50030.0 to 34.9 ...... 40 110.0 to 114.9.. 1,70035.0 to 39.9 170 115.0 or 1,900

greater.

(2) The maximum hazardous wastefiring rate does not exceed at any time Ipercent of the total fuel requirements forthe device (hazardous waste plus otherfuel) on a volume basis;

(3) The hazardous waste has aminimum heating value of 5,000 Btu/lb,as generated; and

(4) The hazardous waste fuel does notcontain (and is not derived from) EPAHazardous Waste Nos. F020, F021, F022,F023, F026, or F027.

(b) Mixing with nonhazardous fuels. Ifhazardous waste fuel is mixed with anonhazardous fuel, the quantity ofhazardous waste before such mixing isused to comply with paragraph (a).

(c) Multiple stacks. If an owner oroperator burns hazardous waste in morethan one on-site boiler or industrialfurnace exempt under this section, thequantity limits provided by paragraph(a](1) of this section are implementedaccording to the following equation:

nY Actual Ouantity Burned 0

1=1 Allowable Quantity Burned~o <1.0

where:n means the number of stacks;Actual Quantity Burned means the waste

quantity burned per month in device "I";Allowable Quantity Burned. means the

maximum allowable exempt quantity forstack "i" from the table in (a)(1) above.

Note: Hazardous wastes that are subject tothe special requirements for small quantitygenerators under J 261.5 of this chapter maybe burned in an off-site device under the

exemption provided by § 266.108, but must beincluded in the quantity determination for theexemption.

(d) Notification requirements. Theowner or operator of facilities qualifyingfor the small quantity burner exemptionunder this section must provide a one-time signed, written notice to EPAindicating the following:

(1) The combustion unit is operatingas a small quantity burner of hazardouswaste;

(2) The owner and operator are incompliance with the requirements of thissection; and

(3) The maximum quantity ofhazardous waste that the facility mayburn per month as provided byI 266.108(a)(1).

(e) Recordkeeping requirements. Theowner or operator must maintain at thefacility for at least three years sufficientrecords documenting compliance withthe hazardous waste quantity, firingrate, and heating value limits of thissection. At a minimum, these recordsmust indicate the quantity of hazardouswaste and other fuel burned in each unitper calendar month, and the heatingvalue of the hazardous waste.(Approved by the Office of Management andBudget under control number 2050-0073)

§ 266.109 Low risk waste exemption.(a) Waiver of DRE standard. The DRE

standard of § 266.104(a) does not applyif the boiler or industrial furnace isoperated in conformance with (a)(1) ofthis section and the owner or operatordemonstrates by procedures prescribedin (a)(2) of this section that the burningwill not result in unacceptable adversehealth effects.

(1) The device shall be operated asfollows:

(i) A minimum of 50 percent of fuelfired to the device shall be fossil fuel,fuels derived from fossil fuel, tall oil, or,if approved by the Director of a case-by-case basis, other nonhazardous fuelwith combustion characteristicscomparable to fossil fuel. Such fuels aretermed "primary fuel' for purposes ofthis section. (Tall oil is a fuel derivedfrom vegetable and rosin fatty acids.)The 50 percent primary fuel firing rateshall be determined on a total heat orvolume input basis, whichever results inthe larger volume of primary fuel fired;

(ii) Primary fuels and hazardous wastefuels shall have a minimum as-firedheating value of 8,000 Btu/lb;

(ii) The hazardous waste is fireddirectly into the primary fuel flame zoneof the combustion chamber, and

(iv) The device operates inconformance with the carbon monoxidecontrols provided by § 266.104(b)(1)

7225




Devices subject to the exemptionprovided by this section are not eligiblefor the alternative carbon monoxidecontrols provided by § 266.104(c).

(2) Procedures to demonstrate that thehazardous waste burning will not poseunacceptable adverse public healtheffects are as follows:

(i) Identify and quantify thosenonmetal compounds listed in appendixVI, part 261 of this chapter that couldreasonably be expected to be present inthe hazardous waste. The constituentsexcluded from analysis must beidentified and the basis for theirexclusion explained;

(ii) Calculate reasonable, worst caseemission rates for each constitutentidentified in paragraph (a)(2)(i) of thissection by assuming the device achieves99.9 percent destruction and removalefficiency. That Is, assume that 0.1percent of the mass weight of eachconstitutent fed to the device is emitted,

(iii) For each constituent identified inparagraph (a)(2)(i] of this section, useemissions dispersion modeling to predictthe maximum annual average groundlevel concentration of the constituent.

(A) Dispersion modeling shall beconducted using methods specified in§ 266.106(h).

(B] Owners and operators of facilitieswith more than one on-site stack from aboiler or industrial furnace that Isexempt under this section must conductdispersion modeling of emissions fromall stacks exempt under this section topredict ambient levels prescribed by thisparagraph.

(iv) Ground level concentrations ofconstituents predicted under paragraph(a)(iii) of this section must not exceedthe following levels:

(A) For the noncarcinogeniccomponds listed in appendix IV of thispart, the levels established in appendixIV;

(B) For the carcinogenic compoundslisted in appendix V of this part, the sumfor all constituents of the ratios of theactual ground level concentration to thelevel established in appendix V cannotexceed 1.0; and

(C) For constituents not listed inappendix IV or V, 0.1 micrograms percubic meter.

(b) Waiver of particular matterstandard. The particulate matterstandard of § 266.105 does not apply if:

(1) The DRE standard is waived underparagraph (a) of this section; and

(2) The owner or operator complieswith the Tier I metals feed ratescreening limits provided by, § 266.106(b) or (e).

§ 266.110 Waiver of DRE trial bum forboilers.

Boilers that operate under the specialrequirements of this section, and that donot burn hazardous waste containing (orderived from) EPA Hazardous WasteNos. F020. F021, F022, F023, F026, orF027, are considered to be inconformance with the DRE standard of§ 266.104(a), and a trial bum todemonstrate DRE is waived. Whenburning hazardous waste:

(a) A minimum of 50 percent of fuelfired to the boiler shall be fossil fuel,fuels derived from fossil fuel, tall oil, or,if approved by the Director on a case-by-case basis, other nonhazardous fuelwith combustion characteristicscomparable to fossil fuel. Such fuels aretermed "primary fuel" for purposes ofthis section. (Tall oil is a fuel derivedfrom vegetable and rosin fatty acids.)The 50 percent primary fuel firing rateshall be determined on a total heat orvolume input basis, whichever results inthe larger volume of primary fuel fired;

f(b) Boiler load shall not be less than40 percent. Boiler load is the ratio at anytime of the total heat input to themaximum design heat input;

(c) Primary fuels and hazardous wastefuels shall have a minimum as-firedheating value of 8,000 Btu/lb, and eachmaterial fired in a burner wherehazardous waste is fired must have aheating value of at least 8,000 Btu/lb, as-fired:

(d) The device shall operate inconformance with the carbon monoxidestandard provided by § 266.104(b)(1).Boilers subject to the waiver of the DREtrial burn provided by this section arenot eligible for the alternative carbonmonoxide standard provided by§ 266.104(c);

(e) The boiler must be a watertubetype boiler that does not feed fuel usinga stoker or stoker type mechanism; and

(f ) The hazardous waste shall be fireddirectly into the primary fuel flame zoneof the combustion chamber with an airor steam atomization firing system,mechanical atomization system, or arotary cup atomization system under thefollowing conditions:

(1) Viscosity. The viscosity of thehazardous waste fuel as-fired shall notexceed 300 SSU;

(2) Particle size. When a high pressureair or steam atomizer, low pressureatomizer, or mechanical atomizer isused, 70% of the hazardous waste fuelmust pass through a 200 mesh (74micron screen, and when a rotary cupatomizer is used. 70% of the hazardouswaste must pass through a 100 mesh(150 micron screen;

(3) Mechanical atomization systems.Fuel pressure within a mechanical

atomization system and fuel flow rateshall be maintained within the designrange taking into account the viscosityand volatility of fuel;

(4) Rotary cup atomization systems.Fuel flow rate through a rotary cupatomization system must be maintainedwithin the design range taking intoaccount the viscosity and volatility ofthe fuel.

§ 266.111 Standards for direct transfer.

(a) Applicability. The regulations inthis section apply to owners andoperators of boilers and industrialfurnaces subject to § § 266.102 or 266.103if hazardous waste is directlytransferred from a transport vehicle to aboiler or industrial furnace without theuse of a storage unit.

(b) Definitions. (1) When used in thissection, the following terms have themeanings given below:

Direct transfer equipment means anydevice (including but not limited to, suchdevices as piping, fittings, flanges,valves, and pumps) that is used todistribute, meter, or control the flow ofhazardous waste between a container(i.e., transport vehicle) and a boiler orindustrial furnace.

Container means any portable devicein which hazardous waste istransported, stored, treated, orotherwise handled, and includestransport vehicles that are containersthemselves (e.g., tank trucks, tanker-trailers, and rail tank cars], andcontainers placed on or in a transportvehicle.

(2) This section references severalrequirements provided in subparts I andJ of parts 264 and 265. For purposes ofthis section, the term "tank systems" inthose referenced requirements meansdirect transfer equipment as defined inparagraph (b)(1) of this section.

(c) General operating requirements.(1) No direct transfer of a pumpablehazardous waste shall be conductedfrom an open-top container to a boiler orindustrial furnace.

(2) Direct transfer equipment used forpumpable hazardous waste shall alwaysbe closed, except when necessary toadd or remove the waste, and shall notbe opened, handled, or stored in amanner that may cause any rupture orleak.

(3) The direct transfer of hazardouswaste to a boiler or industrial furnaceshall be conducted so that it does not:

(i) Generate extreme heat or pressure,fire, explosion, or violent reaction;

(ii) Produce uncontrolled toxic mists,fumes, dusts, or gases in sufficientquantities to threaten human health;




(iii) Produce uncontrolled flammablefumes or gases in sufficient quantities topose a risk of fire or explosions;

(iv) Damage the structural integrity ofthe container or direct transferequipment containing the waste:

(v) Adversely affect the capability ofthe boiler or industrial furnace to meetthe standards provided by § § 266.104through 266.107; or

(vi) Threaten human health or theenvironment.

(4) Hazardous waste shall not beplaced in direct transfer equipment, if itcould cause the equipment or itssecondary containment system torupture, leak, corrode, or otherwise fail.

(5) The owner or operator of thefacility shall use appropriate controlsand practices to prevent spills andoverflows from the direct transferequipment or its secondary containmentsystems. These include at a minimum:

(i) Spill prevention controls (e.g.,check valves, dry discount couplings);and

(ii) Automatic waste feed cutoff to useif a leak or spill occurs from the directtransfer equipment.

(d) Areas where direct transfervehicles (containers) are located.Applying the definition of containerunder this section, owners and operatorsmust comply with the followingrequirements:

(1) The containment requirements of§ 264.175 of this chapter;

(2) The use and managementrequirements of subpart I, part 265 ofthis chapter, except for § § 265.170 and265.174; and

(3) The closure requirements of§ 264.178 of this chapter.

(e) Direct transfer equipment. Directtransfer equipment must meet thefollowing requirements:

(1) Secondary containment. Ownersand operators shall comply with thesecondary containment requirements of§ 265.193 of this chapter, except forparagraphs 265.193 (a), (d), (e), and (i) asfollows:

(i) For all new direct transferequipment, prior to their being put intoservice; and

(ii) For existing direct transferequipment within 2 years after August21, 1991.

(2) Requirements prior to meetingsecondary containment requirements. (I)For existing direct transfer equipmentthat does not have secondarycontainment, the owner or operatorshall determine whether the equipmentis leaking or is unfit for use. The owneror operator shall obtain and keep on fileat the facility a written assessmentreviewed and certified by a qualified,registered professional engineer in

accordance with § 270.11(d) of thischapter that attests to the equipment'sintegrity by August 21, 1992.

(ii) This assessment shall determinewhether the direct transfer equipment Isadequately designed and has sufficientstructural strength and compatibilitywith the waste(s) to be transferred toensure that it will not collapse, rupture,or fail. At a minimum, this assessmentshall consider the following:

(A) Design standard(s), if available,according to which the direct transferequipment was constructed;

(B) Hazardous characteristics of thewaste(s) that have been or will behandled;

(C) Existing corrosion protectionmeasures;

(D) Documented age of the equipment,if available, (otherwise, an estimate ofthe age); and

(E) Results of a leak test or otherintegrity examination such that theeffects of temperature variations, vaporpockets, cracks, leaks, corrosion, anderosion are accounted for.

(iii) If, as a result of the assessmentspecified above, the direct transferequipment is found to be leaking or unfitfor use, the owner or operator shallcomply with the requirements of§ 265.196 (a) and (b) of this chapter.

(3) Inspections and recordkeeping. (i)The owner or operator must Inspect atleast once each operating hour whenhazardous waste is being transferredfrom the transport vehicle (container) tothe boiler or industrial furnace:

(A) Overfill/spill control equipment(e.g., waste-feed cutoff systems, bypasssystems, and drainage systems) toensure that it is in good working order;

(B) The above ground portions of thedirect transfer equipment to detectcorrosion, erosion, or releases of waste(e.g., wet spots, dead vegetation); and

(C) Data gathered from monitoringequipment and leak-detectionequipment, (e.g., pressure andtemperature gauges) to ensure that thedirect transfer equipment is beingoperated according to its design.

(ii) The owner or operator mustinspect cathodic protection systems, ifused, to ensure that they are functioningproperly according to the scheduleprovided by § 265.195(b) of this chapter:

(iii) Records of inspections madeunder this paragraph shall bemaintained in the operating record atthe facility, and available for inspectionfor at least 3 years from the date of theinspection.

(4) Design and installation of newancillary equipment. Owners andoperators must comply with therequirements of § 265.192 of this chapter.

(5) Response to leaks or spills.Owners and operators must comply withthe requirements of 1 265.196 of thischapter.

(6) Closure. Owners and operatorsmust comply with the requirements of§ 265.197 of this chapter, except for§ 265.197 (c)(2) through (c)(4).(Approved by the Office of Management andBudget under control number 2050-0073)

§ 266.122 Regulation of residues.A residue derived from the burning or

processing of hazardous waste in aboiler or industrial furnace is notexcluded from the definition of ahazardous waste under § 261.4(b) (4),(7), or (8) unless the device and theowner or operator meet the followingrequirements:

(a) The device meets the followingcriteria:

(1) Boilers. Boilers must burn coal andat least 50% of the heat input to theboiler must be provided by the coal;

(2) Ore or mineral furnaces. Industrialfurnaces subject to § 261.4(b)(7) mustprocess at least 50% by weight normal,nonhazardous raw materials;

(3) Cement kilns. Cement kilns mustprocess at least 50% by weight normalcement-production raw materials;

(b) The owner or operatordemonstrates that the hazardous wastedoes not significantly affect the residueby demonstrating conformance witheither of the following criteria:

(1) Comparison of waste-derivedresidue with normal residue. The waste-derived residue must not containappendix VIII. part 261 constituents(toxic constituents) that couldreasonably be attributable to thehazardous waste at concentrationssignificantly higher than in residuegenerated without burning or processingof hazardous waste, using the followingprocedure. Toxic compounds that couldreasonably be attributable to burning orprocessing the hazardous waste(constituents of concern) include toxicconstituents in the hazardous waste,and the organic compounds listed inappendix VIII of this part that may begenerated as products of incompletecombustion. Sampling and analysesshall be in conformance with proceduresprescribed In Test Methods forEvaluating Solid Waste, Physical!Chemical Methods, incorporated byreference in § 260.11(a) of this chapter.

(i) Normal residue. Concentrations oftoxic constituents of concern in normalresidue shall be determined based onanalyses of a minimum of 10 compositesamples. The upper 95% confidence levelabout the mean of the concentration inthe normal residue shall be considered

7227




the statistically-derived concentration inthe normal residue. If changes in rawmaterials or fuels reduce thestatistically-derived concentrations ofthe toxic constituents of concern in thenormal residue, the statistically-derivedconcentrations must be revised orstatistically-derived concentrations oftoxic constituents in normal residuemust be established for a new mode ofoperation with the new raw material orfuel. To determine the upper 95%confidence level about the mean of theconcentration in the normal residue, theowner or operator shall use statisticalprocedures prescribed in "StatisticalMethodology for Bevill ResidueDeterminations" in appendix IX of thispart.

(ii) Waste-derived residue.Concentrations of toxic constituents ofconcern in waste-derived residue shallbe determined based on analysis ofsamples composited over a period of notmore than 24 hours. The concentrationof a toxic constituent in the waste-derived residue is not considered to be

significantly higher than in the normalresidue if the concentration in thewaste-derived residue does not exceedthe concentration established for thenormal residue under paragraph (b)(1)(i)of this section; or

(2) Comparison of waste-derivedresidue concentrations with health-based limits--(i) Nonmetal constituents.The concentrations of nonmetal toxicconstituents of concern (specified inparagraph (b)(1) of this section) in thewaste-derived residue must not exceedthe health-based levels specified inappendix VII of this part. If a health-based limit for a constituent of concernis not listed in appendix VII of this part,then a limit of 0.002 micrograms perkilogram or the level of detection (usinganalytical procedures prescribed in SW-846), whichever is higher, shall be used;,and

(ii) Metal constituents. Theconcentration of metals in an extractobtained using the ToxicityCharacteristic Leaching Procedure of§ 261.24 of this chapter must not exceed

the levels specified in appendix VII ofthis part; and

(c) Records sufficient to documentcompliance with the provisions of thissection must be retained for a period ofthree years. At a minimum, the followingshall be recorded:

(1) Levels of constituents in appendixVIII, part 261, that are present in waste-derived residues;

(2) If the waste-derived residue iscompared with normal residue underparagraph (b)(1) of this section:

(i) The levels of constituents inappendix VIII, part 261, that are presentin normal residues; and

(ii) Data and information, includinganalyses of samples as necessary,obtained to determine if changes in rawmaterials or fuels would reduce theconcentration of toxic constituents ofconcern in the normal residue.

3. Appendices I through X are addedto part 266 as follows:

Appendix 1- Tier I and Tier II FeedRate and Emissions Screening Limits forMetals

TABLE I-A.-TIER I AND TIER II FEED RATE AND EMISSIONS SCREENING LIMITS FOR CARCINOGENIC METALS FOR FACILIES INNONCOMPLEX TERRAIN

[Values for urban areas]

Terrain adjusted eff. stack ht. (m) AntImony (g/hr) Badrum (g/hr) Lead (g/hr) Mercury (g/hr) Silver (g/hr) Thallfum (g/h)

4 ............... .. 6.OE+01 1.0E+04 1.8E+01 6.OE+01 6.0E+02 6.0E+016 ........................... 6.8E+01 1.1E+04 2.0E+01 6.8E+01 8.8E+02 6.8E+018 ..................................................................... 7.6E+01 1.3E+04 2.3E+01 7.6E+01 7.6E+02 7.6E+0110 .............. . . 8.6E+01 1.4E+04 2.6E+01 8.6E+01 8.6E+02 8.6E+0112 ................................................................ 9.6E+01 1.7E+04 3.OE+01 9.6E+01 9.6E+02 9.6E+0114 .................................................................... 1;1E+02 1.8E+04 3.4E+01 1.1E+02 1.1E+03 1.1E+0216 ............... 1.3E+02 2.1E+04 3.6E+01 1.3E+02 1.3E+03 1.3E+0218 ................................................................. 1.4E+02 2.4E+04 4.3E+01 1.4E+02 1.4E+03 1.4E+0220 ........... . .................................................... 1.6E+02 2.7E+04 4.6E+01 1.6E+02 1.6E+03 1.6E+0222 ... ... . . 1.8E+02 3.0E+04 5.4E+01 1.8E+02 1.8E+03 1.8E+0224 ............................................................... 2.0E+02 3.4E+04 6.0E+01 2.0E+02 2.0E+03 2.0E+0226 .................................................................. 2.3E+02 3.9E+04 6.8E+01 2.3E+02 2.3E+03 2.3E+0228 ..................................................................... 2.6E+02 .4.3E+04 7.8E+01 2.6E+02 2.6E+03 2.6E+0230 ................................................................ 3.0E+02 5.0E+04 9.0E+01 3.0E+02 3.OE+03 3.0E+0235 ................................................ . . ... 4.0E+02 6.62+04 1.1E+02 4.OE+02 4.0E+03 4.0E+0240 . ................................................. 4.6E+02 7.8E+04 1.4E+02 4.6E+02 4.6E+03 4.6E+0245 .................................................................... 6.0E+02 1.OE+05 1.8E+02 6.OE+02 6.0E+03 6.OE+0250 ....... ... ... 7.8E+02 1.32+05 2.3E+02 7.8E+02 7.8E+03 7.8E+0255 ........................................................ ........ 9.6E+02 1.7E+05 3.0E+02 9.6E+02 9.6E+03 9.6E+0260 ..................................................................... 1.2E+03 2.0E+05 3.6E+02 1.2E+03 1.2E+04 1.2E+0365 ............... 1.5E+03 2.5E+05 4.3E+02 1.5E+03 1.5E+04 1.5E+0370 .................... . 1.7E+03 2.8E+05 5.OE+02 1.7E+03 1.7E+04 1.7E+0375 .................................................................... 1.9E+03 3.2E+05 5.8E+02 1.9E+03 1.9E+04 1.9E+0380 .................................................................... 2.2E+03 3.6E+05 6.4E+02 2.2E+03 2.2E+04 2.2E+0385 ......... ... . 2.5E+03 4.OE+05 7.6E+02 2.5E+03 2.5E+04 2.5E+0390............. ...... 2.8E+03 4.6E+05 8.2E+02 2.8E+03 2.8E+04 2.8E+0395 ......... 3.2E+03 5.4E+05 9.6E+02 3.22+03 3.2E+04 3.2E+03100 ............... 3.6E+03 6.OE+05 1.1E+03 3.6E+03 3.6E+04 3.6E+03105 .......... 4.0E+03 6.8E+05 1.2E+03 4.02+03 4.0E+04 4.0E+03110 .......................... 4.6E+03 7.8E+05 1.4E+03 4.6E+03 4.6E+04 4.6E+03115 ....... . ........ 5.4E+03 8.6E+05 1.6E+03 5.4E+03 5.4E+04 5.4E+03120 .................... 6.OE+03 1.OE+06 1.8E+03 6.OE+03 6.OE+04 6.0E+03



Federal Register / Vol. 56 No. 35 ] Thursday, February 21, 1991 / Rules and Regulations 7229

TABLE I-B.-TIER I AND TIER II FEED RATE AND EMISSIONS SCREENING LIMITS FOR NONCARCINOGENIC METALS FOR FACIUTIES INNONCOMPLEX TERRAIN

[Values for rural areas]

Terrain ajusted eff. stack ht (m)

4 ...... ... ......... .... . ......................................

4 ............................................

1 6.............. ...............

2 ...... ... . . .......... . ...............2 .. .. ................................................

2 ................................................

10 ................ ................................

8 ... .............................................

55 .......................................

S. .......... ...................................24..-.-... . ................................................

5 .............. ........ ... . ...........

2 ...... ....................................30 ... ....... ............ ............................. .......

0 ..... ........ ..........................

5 . ........... ................................

1 20. ....... ........................5 ............ ......................................

55 .. .......... .. ........ .................................

65..--.-. ............................................

70 ....................... ........ ..........................

75 .. .. ............ ............. .............................

so..5 .... ........ .... ............ .............................

65 ... ... ...... .. .... ..... ....................................

100 .. . ..... ...... ..............................................

110 ........ ...... ...... .........................................

115 . ..... .................... .................................

120 ........ ....... ......... ... ..................................

Antimony (g/hr)

3.1E+013.6E+014.OE +.014.6E+015.8E+016.8E+018.6E+011.1E+021.3E+021.7E+022.2E+022.8E+023.5E+024.3E+027.2E+02I1E+031.5E+032.OE+032.6E+033.4E+034.6E+035.4E+036.4E+037.6E + 039.4E+031.1E+041.3E+041.5E+041.8E+042.2E+042.6E+043.1E+04

Barium (g/hr) Lead (g/hr) Mercury (g/hr) Silver (g/hr)4 4 4 4 h

5.2E+036.OE+036.8E+037.8E +039.6E+031.1E+041.4E+041.8E+042.2E + 042.8E+043.6E+044.6E+045.8E+047.6E +041.2E+051.8E+052.5E+053.3E+054.4E + 055.8F +-057.6E+059.0E + 051AE+061.3E+061.5E-+061.8E+062.2E +062.6E+063.0E+063.6E+064.4E+065.OE+06

9.4E+001.1E+011.2E+011.4E+011.7E+012.1E+012.6E+013.2E+014.0E+015.OE+016.4E+018.2E+011.0E+021.3E+0221 E+023.2E+024.6E + 026.OE + 027.8E+021.0E+031.4E+031.6E+031.9E+032.3E+032.8E+033.3E+033.9E+034.6E+035.4E+036.6E+037.8E+039.2E+03

3.1E+013.6E+014.0E+014.6E+015.8E+016.8E+018.6E+011.IE+021.3E+021.7E+022.2E+022.8E+023.5E+024.3E+027.2E+021.IE+031.5E+032.0E+032.6E+0334E + 034.6E+035.4E+036.4E+037.6E+039.4E+031.1E+041.3E+041.5E+041.8E+042.2E+042.6E+043.1E+04

3.1E+023.6E+024.0E+024.6E+025.8E+026.8E+028.6E+021.1E+031.3E+031.7E + 032.2E+032.8E+033.5E+034.3E+037.2E+031.1E+041.5E+042.OE+042.6E +043.4E+044.6E+045.4E+046.4E+047.6E+049.4E+041.1E+051.3E+051.5E+051.8E+052.2E+052.6E+053.1E+05

TABLE I-C.-TIER I AND TIER II FEED RATE AND EMISSIONS SCREENING LIMITS FOR NONCARCINOGENIC METALS FOR FACILITIES INCOMPLEX TERRAIN

Values for urban and rural areas

Terrain adjusted eft. stack ht. (m) Antimony (glhr) Barium (glhr) Lead (g/hr) Mercury (g/hr) Silver (g/hr) Thallium (g/hr)

.................................................................. 1.4E+01 2-4E+03 4.3E+00 1.4E+01 1.4E+02 1.4E+01

.. .. .. . . ..................................... 2.1E+01 3.5E+03 6.2E+00 2.IE+01 2.1E+02 2.1E+01...................................................... 3.0E+01 5.0E+03 9.2E+00 3.0E+01 3.0E+02 3.0E+01

10 ....................................... 4.3E+01 7.8E+03 1.3E+01 4.3E+01 4.3E+02 4.3E+0112 ....................... . . . . 5.4E+01 9.0E+03 1.7E+01 5.4E+01 5.4E+02 5.4E+0114 .......................................................... 6.8E+01 1.1E+04 2.OE+01 6.8E+01 6.8E+02 6.8E+011 ............................................................. 7.8E+01 1.3E+04 2.4E+01 7.8E+01 7.8E+02 7.8E+01IS .............................................................. 8.6E+01 1.4E+04 2.6E +01 8.6E+01 8.6E+02 8.6E+0120 ............................................................... 9.6E+01 1.6E+04 2.9E+01 9.6E+01 9.6E+02 9.6E+0122 ...... 1.0E+02 1.8E+04 3.2E+01 1.OE+02 1.OE+03 1.0E+02

4 ....................................... 1.2E+02 1.9E+04 3.5E+01 1.2E+02 1.2E+03 1.2E+0226 ........................................................... 1.3E+02 2.2E+04 3.6E+01 1.3E+02 1.3E+03 1.3E+022 ..... .................................................... 1.4E+02 2.4E+04 4.3E+01 1.4E+02 1.4E+03 1.4E+0230 ............. ....... 1.6E+02 2.7E -04 4.6E+01 1.6E+02 1.6E+03 1.6E+0235 . .............. . . 2.0E+02 3.3E+04 5.8E+01 2.0E+02 2.0E+03 2.0E+0240....................... .. ...... . .. 2.4E+02 4.OE+04 7.2E+01 2.4E+02 2.4E+03 2.4E+0245 . ........................................ 3.0E+02 5.0E+04 9.OE+01 3.0E+02 3.OE+03 3.0E+0250 ...................................................... 3.6E+02 6.OE +-04 1.1E+02 3.6E+02 3.6E+03 3.6E+0255.-...................................................... 4.6E+02 7.6E +04 1.4E+02 4.6E+02 4.6E- 03 4.6E+02

60 ........... ................ 5.8E+02 9.4E+04 1.7E+02 5.8E+02 5.8E+03 5.8E+0265 ............................................................ 6.8E+02 1,1E+05 2.1E+02 6.8E+02 6.8E+03 6.8E+027'0.-..-. . . ............ ... ............... 7.8E+02 1.3E+05 2.4E+02 7.8E+02 7.8E+03 7.8E+0275..-.... .............................................. 8.6E+02 1.4E+05 2.6E+02 8.6E+02 8.6E+03 8.6E+02

60 ..................................................... 9.6E+02 1.6E+05 2.9E+02 9.6E+02 9.6E+03 9.6E+0285 ....................................................... 1.1E+03 1.8E+05 3.3E+02 1.1E+03 1.1E+04 1.1E+030.-........................................................ . 1.2E+03 2.0E+05 3.6E+02 1.2E+03 1.2E+04 1.2E+03

S.......... 1.4E+03 2.3E+05 4.0E+02 1.4E+03 1.4E+04 1.4E+03......................... 1.5E+03 2.6E+05 4.6E+02 1.5E+03 1.5E+04 1.5E+03

105 ............................ . 1.7E+03 2.8E+05 5.0E+02 1.7E+03 1.7E+04 1.7E+03S... 1.9E+03 3.2E+05 5.8E+02 1.9E+03 1.9E+04 1.9E+03

.............................................. 2.1E+03 3.6E+05 6.4E+02 2.1E+03 2.1E+04 2.1E+03S....... 2.4E+03 4.OE+05 7.2E+02 2.4E+03 2.4E+04 2.4E+03

Thallium (g/hr)

3.1E+013.6E+014.0E+014.6E+015.8E +016.8E+018.6E+011.1E+021.3E+021.7E+022.2E+022.8E+023.5E + 024.3E+027.2E+021.1E+031.5E+032.0E+032.6E +033.4E+034.6E +035.4E+036.4E+037.6E+039.4E+031.1E+041.3E+041.5E+041.8E+042.2E +042.6E+043.1E+04




TABLE I-D.-TIER I AND TIER II FEED RATE AND EMISSIONS SCREENING LIMITS FOR CARCINOGENIC METALS FOR FACILITIES INNONCOMPLEX TERRAIN

Values for use In urban areas Valuei for use In rural areas

Cadium(g/ Chrmiu(g/ Berlli m g/ admum g/ Chromium (g/ BerylliumTerrain adjusted eff. stack ht (m) Arsenic (g/hr) Cadmium (g/ Chromium (g Beryllium Arsenic (g/hr) (ghr)hr) hr) hr) Asnc(/r Cdmhr) (g Choimr

( / Bryiugh)

4 ........................................................... 4.6E-01 1.1E+00 1.7E-01 8,2E-01 2.4E-01 5.8E-01 8.6E-02 4.3E-016 ............................................................ 54E-01 1.3E+00 1.92-01 9.4E-01 2.8E-01, 6.6E-01 1.0E-01 5.0E-018 ................ . 6.0E-01 1.4E+00 2.2E-01 1.1E+00 3.2E-01 7.62-01 1.1E-01 5.6E-0110 ......................................................... 6.8E-01 1.6E+00 2.4E-01 1.2E+00 3.62-01 8.62-01 1.3E-01 6.4E-0112 .......................................................... 7.6E-01 1.8E+00 2.7E-01 1.4E+00 4.32-01 1.1E+00 1.6E-01 7.8E-0114 ......................................................... 8.6E-01 2.1E+00 3.1E-01 1.5E+00 5.4E-01 1.3E+00 2.0E-01 9.6E-0116 .......................................................... 9.6E+01 2.3E+00 3.5E-01 1.7E+00 6.8E-01 1.6E+00 2.4E-01 1.2E+0018 .......................................................... 1.1E+00 2.6E+00 4.0E-01 2.0E+00 8.2E-01 2.0E+00 3.0E-01 1.5E+0020 .......................................................... 1.2E+00 3.0E+00 4.4E-01 2.2E+00 1.0E+00 2.5E+00 3.7E-01 1.9E+0022 .......................................................... 1.4E+00 3.4E+00 5.0E-01 2.5E+00 1.3E+00 3.2E+00 4.8E-01 2.4E+0024 ............... . 1.6E+00 3.9E+00 5.8E-01 2.8E+00 1.7E+00 4.0E+00 6.0E-01 3.0E+0026 ............................. 1.8E+00 4.3E+00 6.4E-01 3.2E+00 2.1E+00 5.02+00 7.6E-01 3.9E+0028 ........................................................ 2.0E+00 4.82+00 7.2E-01 3.6E+00 2.7E+00 6.42+00 9.8E-01 5.0E+0030 .......................................................... 2.3E+00 5.4E+00 8.2E-01 4.0E+00 3.5E+00 8.2E+00 1.2E+00 6.2E+0035 .......................................................... 3.0E+00 6.8E+00 1.0E+00 5.4E+00 5.4E+00 1.3E+01 1.9E+00 9.6E+0040 .......................................................... 3.62+00 9.0E+00 1.3E+00 6.8E+00 8.2E+00 2.0E+01 3.0E+00 1.5E+0145 ......................................................... 4.6E+00 1.1E+01 1.7E+00 8.6E+00 1.1E+01 2.8E+01 4.2E +00 2.1E+0150 .................. 6.0E+00 1.4E+01 2.2E+00 1.1E+01 1.5E+01 3.7E+01 5.4E+00 2.8E+0155 ......................................................... 7.6E+00 1.8E+01 2.7E+00 1.4E+01 2.0E+01 5.0E+01 7.2E +00 3.6E+0160 .......................................................... 9.4E+00 2.2E+01 3.4E+00 1.7E+01 2.7E+01 6.4E+01 9.6E+00 4.8E+0165 ......................................................... 1.1E+01 2.8E+01 4.2E+00 2.1E+01 3.6E+01 8.6E+01 1.3E+01 6.4E+0170 .......................................................... 1.3E+01 3.1E+01 4.6E+00 2.4E+01 4.3E+01 1.02+02 1.5E+01 7.6E+0175 ......................................................... 1.5E+01 3.6E+01 5.4E+00 2.7E+01 5.0E+01 1.2E+02 1.8E+01 9.0E+0180 .......................................................... 1.7E+01 4.0E+01 6.0E+00 3.0E+01 6.0E+01 1.4E+02 2.2E+01 1.1E+0285 .......................................................... 1.9E+01 4.6E+01 6.8E+00 3.4E+01 7.2E+01 1.7E+02 2.6E+01 1.3E+0290 .......................................................... 2.2E+01 5.0E+01 7.8E+00 3.9E+01 8.6E+01 2.0E+02 3.0E+01 1.5E+0295 .......................................................... 2.5E+01 5.8E+01 9.0E+00 4.4E+01 1.0E+02 2.4E+02 3.6E+01 1.8E+02100 ........................................................ 2.8E+01 6.8E+01 1.0E+01 5.0E+01 1.2E+02 2.9E+02 4.3E+01 2.2E+02105 ........................................................ 3.2E+01 7.6E+01 1.1E+01 5.6E+01 1.4E+02 3.4E+02 5.0E+011 2.6E+02110 ........................................................ 3.6E+01 8.6E+01 1.3E+01 6.4E+01 1.7E+02 4.0E+02 6.0E+01 3.0E+02115 . . . . . . . 4.0E+01 9.6E+01 1.5E+01 7.2E+01 2.0E+02 4.8E+02 7.2E+01 3.6E+02120 ....................................................... 4.6E+01 1.1E+02 1.7E+01 8.2E+01 2.4E+02 5.8E+02 8.6E+01 4.3E+02

TABLE I-E.-TIER I AND TIER II FEED RATE AND EMISSIONS SCREENING LIMITS FOR CARCINOGENIC METALS FOR FACILITIES IN

COMPLEX TERRAIN

Values for use in urban and rural areas

Terrain adjusted eff. stack ht. (m) Arsenic (g/hr) Cadmium (g/hr) Chromium (g/hr) Beryllium (g/hr)

4 ............ 1.1E-01 2.6E-01 4.0E-02 2.0E-016 ............................................................................................. 1.6E-01 3.9E-01 5.82-02 2.9E-01a .................................... 2 4E -01 4K En a F - : . E 0i

10. 3.5E-0112 ..................................... 4.3-0114 ..................................... 5.E-0116 ..................................... 6.0E-0118 ........................................... ....................................... 6.8E-01

22 .................................................................24 .................................................................26 .................................................................28 .................................................................30 ................................................................35 ................................................................40 ................................................................

75 .....................................................................................80 ..............................................................................................85 ..............................................................................................90 ..............................................................................................95 .............................................................................................100 ..........................................................................................

105 ............................................................................................110 ............................................................................................115 ...........................................................................................120 ............................... ................................................ .

7.6E-018.2E-019.0E-011.0E+001.1E+001.2E+001.5E+001.9E+002.4E+002.9E+003.5E+004.3E+005.4E+006.0E+006.8E+007.6E+008.2E+009.4E+001.0E+011.2E+011.3E+011.5E+011.7E+011.9E+01

5.8IE-U1 C.01::--U ".8.2E-01 1.3E-01 6.2E-011.0E+00 1.5E-01 1.6E-011.3E+00 1.9E-01 9.4E-011.4E+00 2.2E-01 1.1E+001.6E+00 2.4E-01 1.2E+001.8E+00 2.7E-01 1.3E+001.9E+00 3.0E-01 1.5E+002.1E+00 3.3E-01 1.6E+002.4E+00 3.6E-01 1.8E+002.7E+00 4.0E-01 2.OE+003.0E+00 4.4E-01 2.2E+003.7E+00 5.4E-01 2.7E+004.6E+00 6.8E-01 3.4E+005.4E+00 8.4E-01 4.2E+006.8E+00 1.0E+00 5.OE+008.4E+00 1.3E+00 6.4E+001.0E+01 1.5E+00 7.8E+001.3E+01 1.9E+00 9.6E+001.4E+01 2.2E+00 1.1E+011.6E+01 2.4E+00 1.2E+011.8E+01 2.7E+00 1.3E+012.02+01 3.0E+00 1.5E+012.3E+01 3.4E+00 1.7E+012.5E+01 4.0E+00 1.9E+012.8E+01 4.3E+00 2.1E+013.2E+01 4.8E+00 2.4E+013.5E+01 5.4E+00 2.7E+014.0E+01 6.OE+00 3.0E+014.4E+01 6.4E+00 3.3E+01

L .1. ________________________________________ 4.



Federal Register I Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations 7231

Appedix H.-Tier I Feed Rate Screening Limits for Total Chlorine and Chloride

TIER I FEED RATE SCREENING LIMITS FOR CHLORINE FOR FACILITIES IN NONCOMPLEX AND COMPLEX TERRAIN

Noncomplex ComplexTerrain-adjusted effective stack height (m) Urban (Ib/hr) Rural Qb/hj Qb/hr)

4 ... ........... ......................................... ..... I........ ..... ...................... ......... ..... ...... . ..................... ................................................ 1.8E- 02 9.2E- 03 4.1E- 03

6 ............................................................................................................................................................................................ 2.0E-02 1.OE- 02 6.1E- 038 .................................................................................................................................................................................... 2.2E- 02 1.2E- 02 9.OE- 0310 .............................................................................................................................................................................................. 2.5E- 02 1.4E-02 1.3E-0212 ................................................................................................... . . ... ................. .......................................... 2.9E- 02 1.7E- 02 1.6E- 0214 ....................................................................................................................................................................................... 3.3E- 02 2.0E- 02 2.0E- 0216 .......................................................................................................................................................................................... 3 7E- 02 2.5E- 02 2.3E- 0218 ............................................................... ; ..................................................................................................................... 4.1E- 02 3.2E- 02 2.5E- 022 ... ..... .. ..... . .......... ............................ . .......................................... ............................................................... 4 7E- 02 3.9E- 02 2.9E- 0222 ..... ..................................................................................................................... .................... .......................................... 5.3E- 02 5.0E- 02 3.1E- 0224 ............................................................................................................................................................................................ 6.0E- 02 6.3E- 02 3.5E- 0226 .......................................................................................................................................................................................... 6.8E- 02 1.3E- 02 3.8E- 0228 ............................................................................................................................................................................................. 7.6E- 02 1.0E- 01 4.2E- 0230 ............................................................................................................... ......................................................................... 8. E- 02 1.3E- 01 4.7E- 0235 ................................................................................................................................................................................................. 1.21E- 01 2.E- 01 5.8E- 0240 ........................................................................................................................................................................................ 1. E- 01 3.21E- 01 7.2E- 0245 ....................................... ................................................................................................................................................. 1.8E- 01 4 4E- 01 8.8E- 02so .......................................................................................................................................................................................... .3E- 01 5.8E- 01 1.1E- 0155 ....................................................................................................................................................................................... 2.9E- 01 7.7E- 01 1.4E- 0160 ......................................................................................................................................................................................... 3.6E- 01 1.0E+ 00 1.7E- 0165 ............................................................................................................................................................................................ 4.3E- 01 1.4E+ 00 2.0E- 0170 ...................................................................................................................................................................................... 5.0E- 01 1.6E+ 00 2.3E- 0175 .............................................................................................................................................................................................. 5.6E- 01 1.9E+ 00 2.5E- 0180 ........ ....... .............................. .... ........ .................................. .... .............. ............................ . .............................................. 6.3E- 01 2.2E + 00 2.9E- 01

85 ................................................................................................................................................................................................. 7.3E- 01 2.8E+ 00 3.2E- 0190 ................................................ ........................................................................................................................................ 8.3E- 1 3.2E+ 00 3.6E- 0195 ......................................................................................................................................................................................... 9.3E- 01 3.8E+ 00 4.0E- 01100 ........................................ ..................................... ..... ................................................ .................................................. ........ 1.1E+ 00 4.6E+ 00 4.4E- 01105 ............................................................................................. ............................. . .................................................... .............. 1.2E+ 00 '5.4E+ 00 5.0E- 01110 ..... ... ................................... . ..................... ............. .................. ............... ........... ................................ ............................. 1.4E+ 00 6.5E+ 00 5,6E- 01

115 ........................................................................................................................................................................................ 1.6E+ 00 7.7E+ 00 6.2E- 01120 ... .................................................... ..... ........................................................ ................... ..................................................... 1.8E+ 00 9.1E+ 00 7.1E- 01

Appendix Il1-Tier H Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

TIER II EMISSIONS SCREENING LIMITS FOR C AND HCI IN NONCOMPLEX TERRAIN

1 Values for use In urban areas Values for use in rural areasTerrain-adjusted effective stack height ()(g/sec) C (gsec) CI (g/ec)

4 ........... ............................... . ........ .................. ....................................... ........................6 .............................................. ............................................ ......................................................

8.................... ....... . ................... ..... ......... ..........................................................

10 ..................................................................................................... .......................... ..............

12 ......................................................................................................................................................

14 ............................................................................................................... .. ...

16 ...............................................................................................................................................

18 ............................................................................... ...............................................................................

20 ........................................................................................................................................................

22 .....................................................................................................................................................

55..

60.65.70.75....80_..~

85.....90......95.

2.3E-032.5E-032.8E-033.2E-033.6E-034.1E-034.7E-035.2E-035.9E-036.7E-037.6E-038.5E-039.6E-031.11E-021.5E-021.7E-022.3E-022.9E-023.6E-024.5E-025.5E-026.3E-027.1E-028.0E-029.2E-021.OE-011.2E-01

4.OE-014.4E-014.9E-015.6E-016.3E-017.2E-018.2E-019.1E-011.0E+001.2E+001.3E+001.5E+001.7E+001.9E+002.6E+003.OE+004.OE+005.1E+006.3E+007.9E+009.6E+001.1E+011.2E+011.4E+011.6E+011.8E+012.IE+01

1.2E-031.3E-031.5E-031.7E-032.1E-032.5E-033.2E-034.OE-034.9E-036.3E-038.OE-031.OE-021.3E-021.6E-022.7E-024.OE-025.6E-027.3E-029.7E.021.3E-011.7E-012.OE-012.4E-012.8E-013.5E-014.OE-014.8E-01

2.OE-012.3E-012.6E-013.OE-013.7E-014.4E-015.6E-017.OE-018.6E-011.1E+001.4E+001.8E+002.3E+002.8E 4-004.7E+007.OE+009.8E+001.3E+011.7E+012.2E+013.0E+013.5E+0i4.2E+014.9E+016.IE+017.0E+018.4E+01

I .... ...................... ... ........ .......... ........ I

...... ... ........ . ......... ............. .. ... ............... . ........ ................... ......... . ..... ....... ........ .... ....... ....................... ............ - - -

............................................ .............. ................... ... .............. ...... .. ........... ..................................... .... ...

... ...... ... ...... . ... ................................................... ........ .......................... ..... .................................. .........................

................................. ......... ............................................................... .................... ........ .... ............ .



7232 Federal Register / Vol. 50, No. 35 1 Thursday, February 21, 1991 / Rules and Regulations

TIER II EMISSIONS SCREENING LIMITS FOR Cl6 AND HCI IN NONCOMPLEX TERRAIN-Continued

Values for use In urban areas Values for use in rural areasTerraIn-adjusted effective stack height (m) C6I (/ec) Ha (g/sec) Cl (g/sec) HCI (g/sec)

100~~~~~~~~~~~~~ ... ,............. ...................... ....................... 1.3E-01 2.3E+01 5.7E-01 1.012+02

S........... 1.SE-01 2.6E+01 5.7E-01 1.2E+02110 ............................................ .. . ............ ... ..................... .................... ...... ... .......... 1.7E- 01 3.0E+ 01 .E- 0 1 1.4E+ 02

115 ....... ............... .......... ..... .. .. . . ........ ................... 2.0E-01 .5E+01 I.7E-00 1.7E+02120 ........................................................................................ ............................................................. 2.3E-01 A IE+01 1.1+00 2.0E+02

TIER II EMISSIONS SCREENING LIMITS FORC62 AND HCI IN COMPLEX TERRAIN

Terrain-adjusted Values for use In urban and ruraleffective stack areas

height (m) C61 (g/sec) HCI (glsec)

4 ....................... 5.2E-04 9.1E-026 ......................... 7.7E-04 1.4E-018 ......................... 1.1E-03 2.0E-0110....... 1.6E-03 2.8E-0112 . ............ 2.OE-03 3.5E-0114............ 2.5E-03 4AE-0116 ....... 2.9E-03 5.1E-0118 ..... ...... 3.2E-03 5.6E-0120 . . 3.6E-03 6.3E-0122 ............ 3.9E-03 6.8E-0124 ........ . . 4.4E-03 7.7E-0126 ...................... 4.8E-03 8.4E-0128 ................... 5.3E-03 9.3E-0130 .................. 5.9E-03 1.OE+0035 .......... 7.3E-03 1.3E+0040 ........... 9.1E-03 1.6E+0045 ... ..... . 1.1E-02 1.9E+0050 .............. 1.3E-02 2.3E+0055 ........................ 1.7E-02 3.OE+0060 ......................... 2.1E-02 3.7E+0065 ......................... 2.5E-02 4.4E+0070 .......................... 2.9E-02 5.1E+0075 ........... 3.2E-02 5.6E+0080 ......................... 3.6E-02 6.3E+0085 ........... 4.0E-02 7.OE+0090 ....... .......... 4.5E-02 7.9E+0095 ......................... 5.1E-02 8.9E+00100.................... 5.6E-02 9.8E+00105 ..................... 8.3E-02 1.1E+01110 ................. 7.1E-02 1.2E+01115 . .............. 7.9E-02 1.4E+01120 ..................... 8.9E-02 1.6E+01

APPENDIX IV.-REFERENCE AIRCONCENTRATIONS*

Constituent CAS No. IRAC (ug/

Acetaldehyde .....................Acetonitrile ........................Acetophenone ..................Acrolein ..............................Aldicarb .............................Aluminum Phosphide ........Allyl Alcohol .......................Antimony.......................Barium ..........................Barium Cyanide .................Bromomethane .................Calcium Cyanide ..............Carbon DisUlfide ................Chloral ........ .....................Chlorine (free) ..................2-Chloro-1,3-butadlene .....Chromium III ....................Copper Cyanide ................Cresols ..............................Cumene ..................

APPENDIX IV,.-REFERENCE AIR

CONCENTRATIONS-Continued

Conttuent CAS No._I RACJg/

Cyanide (free)......Cyanogen ........................Cyanogen Bromide ..........DI-n-butyl Phthalate ..........o-Dichlorobenzene .....p-Dichlorobenzene ............Dlchlrodifluoromethane..2,4-Dichlorophenol ............Diethyl Phthalate ...............Dimethoate .......................2,4-Dinitrophenol .......Dnoseb..........................Diphenylamine ...................Endosufan .........................Endrln ..............................Fluorine ..............................Formic Acid .......................Glycldyaldehyde ...............Hexachlorocyclopenta-

diene ............................Hexachlorophene ..........Hydrocyanic Acid ..............Hydrogen Chloride ..........Hydrogen Sulfide .............Isobutyl Alcohol .................Lead ...............................Maleic Anyhdrlde ........Mercury .....Methacrylontrile.,Methomyl ...........................Methoxychlor ...................Methyl Chlorocarbonate...Methyt Ethyl Katone.......Metyl Parathion......Nickel Cyanide ..........Nitric Oxide ......................Nitrobenzene ................Pentachlorobenzene.Pentachlorophenol ............Phenol ...............M-Phenylenediamine.......Phenylmercuric AcetatePhosphine ........................Phthalic Anhydride.........Potassium Cyanide_ _Potassium Silver

Cyanide . ............Pyridine .......................Selenlous Acid ...............Selenourea...............Silver . .................Silver Cyanide ..........Sodium Cyanide.........Strychnine .......................1,2,4,5-

Tetrachlorobenzene..2,3,4,6.

Tetrachlorophenol. ....Tetraethyl Lead .....Tetrahydrofuran ................Thallic Oxide ...................Thallium ........ ...Thallium (I) Acetate ........

57-12-15460-19-5506-8-84-74-295-50-1

106-46-775-71-8

120-83-284-66-260-51-551-28-588-85-7

122-39-4115-29-172-20-8

7782-41-464-18-6

765-34-4

77-47-470-30-474-90-8

7647-01-17783-06-4

78-83-17439-92-1

108-31-67439-97-6

126-98-716752-77-5

72-43-579-22-178-93-3

298-00-0557-19-7

10102-43-998-95-3

608-93-587-6-5

108-95-2108-45-2

62-38-47803-51-2

85-44-9151-50-

506-61110-86-1

77830-6-8630-10-4

7440-22-45068-4-9143-33-9

57-24-9

95-94-3

58-90-278-00-2

109-99-91314-32-57440-28-0,563-68-8

20308o

1001010

2003

8000.8

20.920

0.050.350

20000.3

50.32073

3000.091000.30.12050

100080

0.320

1000.80.830305

0.0750.3

20005o

2001353

10030

0.3

0.3

300.0001

100.30.50.5

APPENDIX IV.-REFERENCE AIRCONCENTRATIONS-Continued

Consttent CAS No. RAC ua

Thallium (I) Carbonate ...... 6533-73-9 0.3Thallium (I) Chloride ........ 7791-12-0 0.3Thallium (I) Nitrate ............ 10102-45-1 0.5Thallium Selenite ............. 12039-52-0 0.5Thallium (I) Sulfate...._ 7446-18- 0.075Thlram .......... 137-26-8 5Toluene .......-. .................. 108-88-3 3001.2,4-Trichlorobenzene.... 120-82-1 20Trlchloromonofluoro-

methane ...................... 75-69-4 3002.4.5-Trichlorophonof 95-95-4 100Vanadium Pentoxide . 1314-62-1 20Warfadn ............... 81-81-2 0.3Xylenes . ... . 1330-20-7 80Zinc Cyanide ...................... 557-21-1 60Zinc Phosphide ............... 1314-84-7 0.3

*The RAC for other Appendix VIII Part 261 con-stituents not listed herein or in Appendix V of thisPart is 0.1 ugim3.

APPENDIX V,-RISK SPECIFIC DOSES(1o-1

Unit RsDC riskConstituent (s3 I (ug

N: (m3/ m3ug)

Acrylonhirle ......................

Aldrin ....................

Aniline ..... .........

Arsenic .... ......

erz(a)anthracene .....

Benzidine .........................

Benzo(a)pyrene ..............

Beryllium ........................

Bis(2-chloroeth)ether.

Bis(chloromethylDether

Sis(2-ethylhexyl)phthalate .................

1,3-Butadene ........ .......

Cadmium..._--_-

Carbon Tetrachloride.......

79-06-

107-13-1309-00-2

62-53-3

7440-38-2

56-55-3

71-43-2

92-7-5

50-32-8

7440-41-711-44-4542-88-1

117-81-7106-99-

7440-43-9

56-23-5

1.3E-03 7.7E-03

S.8E-05 I.5E-01

4.9E-03 2.OE-03

.4E-0 1.4E+00

4.3E-03 , 3E-03

9.9E-04 1E-02

1.3E-06 .2E+00

8.7E-02

3.3E-03

:.4E-03

.3E-04

.2E-02

L.SE-04

3.OE-03

4.2E-03

3.OE-02

t.6E-04

).4E-07 1 .2E+01

t.8E -04.6E-02

I.8E-03

1.5E-05

5.6E-03

5.7E-01

75-07-075-05-898-86-2

107-02-8116-06-3

20859-73-8107-18-6

7440-36-07440-39-3

542-62-174-83-9

592-01-875-15-075-87-6

,.......................

126-99-816065-83-1

544-92-31319-77-3

98-82-6



Federal Register / Vol. 56, No. 35 / Thursday, February 21, 1991 / Rules and Regulations 7233

APPENDIX V.-RISK SPECIFIC DOSES(10---Continued

Unit RsD

Constituent CAS skNo. (m31 MU)ug)

Chordane ...........

Chloroform.......

Chloromethane ......

Chromium

DOT ...............

Oibenz(a,h)anthracene..

1,2-Oxomo-3-chorprane ....

1.2-Obromoethane......

1,1 -Oichloroethane

1.2-Dichloroethane ......

1,1-Dichloroethylene......

1,3-Dichtoropropene.......

Didrin .......................

Diethylstiibestrol...........

Dimethylnitrosamine .......

2,4-Dinitrotoluene-.......

1.2-Diphenyydrazine....

1,4-Dioxane ......................

Epichlorohydrin ...............

Ethylene Oxde

Ethylene Dibromide ......

57-74-9

67-66-3

74-87-3

7440-47-3

50-29-3

53.-703

98-12-8

106-93-4

75-34-3

107-06-2

75-35-4

542-75-6

60-57-1

56-53-1

62-75-9

121-14-2122-66-7123-91-1106-89-8

75-21-8

106-93-4

3.7E-04

2.3E-05

3.6E-06

1.2E-02

D.7E-05

1.4E-02

5.3E-03

2.2E-04

2.6E-05

-.6E-05

5.OE-05

3.5E-01

t.6E-03

1.4E-01I

.4E- 02

I.8E-05

2.2E-04

I.4E-06

1.2E-06

1.OE-04

?.2E-04

2.7E-02

.3E-01

1.8E+00

3.3E-04

I.OE-01

7.1E-04

1.6E-03

4.5E-02

3.8E-01

3.E-01

L.0E-01

.9E-05

?.2E-03

.1E-05

r.1E-04

1lE-01

1.5E-02

7.1E+00

1.3E+00

I.0E-01

I5E-02

APPENDIX V.-RISK SPECIFIC DOSES(10-1-Continued

Unit RsDConstituent CAB risk

No. (m3,ug) 3

Formaldehyde ........

Hoptachlor ...-....-...

Heptachlor Epoxlde ....

Hexachlorobenzene......

Hexachlorobutadlene....

Alpha-hexachloro.cyc /heXan.............

Beta-hexachloro-cyclohexane............

Gamma-hexachloro-cyclohexane ......

Hexachlorocyclo-hexane, Technical ........

Hexachlorodibenxo-p-dioxln(1.2 Mixture).....

Hexachloroethane . ......

Hydrazine .....................

Hydrazine Sulfate ... .....

3-Methylcholanthrene......

Methyl Hydrazine...........

Methylene Chloride ......

4,4'-Methylene-bis-2-chloroaniline ................

Nickel . .................

Nickel Refinery Dust......

0-o0-0

76-44.-8

1024-57-3118-74-1

87-68-3

319-84-

319-85-7

58-89-9

67-72-1

302-01-2302-01-2

56-49-5

60-34-4

75-09-2

101-14-4

7440-02-0

7440-02-0

1.3E-05

1.3E-03

2.6E-03

4.9E-04

2.0E-05

7.7E-01

F.7E-03

3.8E-03

2-OE-02

.0E-01

1.8E-03 5.6E-03

5.3E-04 1.9E-02

3.8E-04 2.6E-02

5.1E-04

1.3E+0

4.0E-06

2.9E-03

2.9E-03

2.7E-03

3.IE-04

4.1E-06

4J.7E-05

2.4E-04

2.4E-04

2.0E-02

7.7E-06

2.5E+00

3.4E-03

3.4E-03

3.7E-03

3.2E-02

2.4E+00

.. 1E-01

$.2E-02

$.2E-02

APPENDIX V.-RISK SPECIFIC DOSES

(10- -Continued

Unit RsOConstituent CAS nsk

ug)

Nickel Subsulfide ........ 12035-72-2 4.E-04 ,1E-02

2-NitropfopAne .... .........79-46-9 27E-02 3.7E-04

N-Nitroso-n utylamine. 924-16-3 1.6E-03 8.3E-03

N-Nitroso-n-methylurea.... 684-93-6 B.6E-02 1.2E-04

N-Nit sodiethytamine .... 55-18-5 .3E-02 2.3E-04

N-Nitrosopyrrolline ..... 930-55-2 S.E-04 1.6E-02

Pentachlorontroben-zene.................. 82-68-

8 7.3E-05 1,4E-01PCBs . ............. 1336-

36-3 1.2E-03 B.3E-03Pronamilde .................. .23950-

58-6 4.6E-06 2.2E+00Reserpine .... . ........ 50-55-

5 3.OE-03 3.3E-032,3,7,8-Tetrachloro-

dibenzo-p-dioxn ......... 1746-01-6 .5E+01 2.2E-07

1.1.2,2-Tetrachloroethane ....... 79-34-

5 5.8E-05 1.7E-01Tetrachloroethylene ...-. 127-

18-4 4.8E-07 2.1E+01Thiourea.................. 2-56- .

8 .E-04 1.8-c1,1,2-Trichloroethane 7.".. 79-0-

5 1.6E-05 3.3E-01Trichloroethylene ............ 79-01-

6 1.3E-06 7.7E+002,4,6-Trchloropheno ....... 88-08-

2 5.7E-06 1.8E+00Toxaphene .................. 8001-

35-2 .2E-04 .IE-02Vinyl Chloride .............. 75-01-

4 .E-06 .4E+00

APPENDIX VI.-STACK PLUME RISE

[Estimated Plume Rise (in Meters) Based on Stack Exit Flow Rate and Gas Temperature]

_Exhaust Temperature (K*)Flow rate (m3/s) <325 3 2 5-

35 0 - 400- 1450-I 500- 1600- 700- 180 1000- >149934 39 i j 4 49 j 49 9 j 599 6994.7991999- >1499

0.5-0.9 ...................................1.0-1.9 .....................................

3.0-3.9 ..................5.0-7.4 .. ...... .............. .. .. . . ........7.5-4.9 ................... ............ .........1.0-.4...9..................................

7.05-9.9 ......................................

120.0-124 ...............12.0-19.9 ................................20.0-24.9 ...................25.0-29.9 ............30.0-34.9 .............................35.0-39.9 ...................................40.0-49.9 ....................50.0-59.9 ................... ..60.0-69.9 ..................................70.079.9 .............. ....80.0-89.9 ....... ............

90.0-99.9 ...............................100.0-119.9 .............. ...........




APPENDIX VI.--STACK PLUME RISE--Continued

(Estimated Plume Rise (in Meters) Based on Stack Exit Flow Rate and Gas Temperature]

Exhaust Temperature (K')

Flow rate (m3/s) <325 325- 350- 400- 450- 500- 600- 700- 800- 1000->14349 399 449 499 599 699 799 999 1499

120.0-139.9 ............ ...... .. ... .......................................... 22 28 35 42 46 49 52 55 56 59 81140.0-159.9.............................................. 23 30 36 44 48 51 55 58 59 62 65160.0-179.9 ....................... .................................................. 25 31 38 46 60 54 58 60 62 65 67180.0-199.9 ......................................................................................... 26 32 40 48 52 56 60 63 65 67 70>199.9 .......... ...... 26 33 41 49 54 58 62 65 67 69 73

Appendix ViI.-Health-Based Linits forExclusion of Waste-Derived Residues'

METALS-TCLP ExTRACTCONCENTRATION LIMITS

Concentra-Constituent CAS No. tion limits

(mg/kg)

Antimony ....... ........... 7440-36-0 lxE+00Arsenic .......................... 7440-38-2 5xE+00Barium. ........................ 7440-39-3 lxE+02Beryllium ....... 7440-41-7 7xE-03Cadmium ........................ 7440-43-9 lxE+00Chromium ........... 7440-47-3 5xE+00Lead ........................... 7439-92-1 5xE+00Mercury ........................... 7439-97-6 2xE-01Nickel ........................... 7440-02-0 7xE+01Selum................ 7782-49-2 lxE+00Silver ........... 7440-22-4 5xE+00

NONMETALS-RESIDUE CONCENTRATION

LIMITS

Concentra.ion limitsConstituent CAS No. for residues

I (mg/kg)

Acetonittle... .Acetophenone...........Acrolein .......................Acrylamide .....................Acrylonitrile ................Aldrin .............. ...

Allyl alcohol ..................Aluminum phosphide.Aniline .............................Barium cyanide .............Benz(a)anthraoene.Benzene . .............Benzidine ........................Bs(2-chloroethyl)

ether.Bls(chloromethyl) ether..Bls(2-ethylhexyl)

phthalate.Bromoform . ............Calcium cyanide ......Carbon disulfide .............Carbon tetrachloride ......Chlordane ...............Chlorobenzene .........Chloroform .....................Copper cyankle ............Cresols (Cresylic acd)..Cyanogen . ................DDT ...........................Diben(a. h)-

anthracene

75-05-898-86-2

107-02-879-06-1

107-13-1309-00-2107-18-6

20859-73-862-63-3

542-62-156-65-371-43-292-87-5

111-44-4

42-88-1117-81-7

75-25-2692-01-8

75-15-056-23-557-74-9

108-90-767-86-3

544-92-31319-7-3460-19-6

50-29-353-70-3

2xE-014xE+00SxE-012xE-047xE-042xE-052xE-01lxE-026xE-02lxE+00lxE-045xE-03lxE-063xE-04

2xE-063xE+01

7xE-01IxE-064xE+005xE-033xE-04lxE+006xE-022xE-012xE+00lxE+00IxE-037xE-06

NONMETALS-RESIDUE CONCENTRATIONLIMITS--Continued

Concentra-

Constituent CAS No. oresidues

(mg/kg)

1,2-Dibromo-3.chlorapropane.

p-Dichlorobenzene.Dichlorodfluorometh-

ane.11 -Dichloroethylene.....2,4-Dichlorophenol ........1,3-Dlchloropropene.Dieldrin .......................Diethyl phthalate.Diethylstilbesterol ...........Dimethoate ......................2,4-Dinirotoluene.Diphenylamine.1,2-Diphenylhydrazoe....Endosultfan .................Endrin ...............................Epichlorohydrin ......Ethylene dibromide ........Ethylene oxide ...............Fluorine ..........................Formic acid ..............Ileptachior ........Heptachlor epoxide.Hexachlorobenzene .......Hexachlorobutadiene .....Hexachlorocyclopenta-

diene.Hexachlorodibenzo-p.

dioxins.Hexachloroethane .........Hydrazine .......................Hydrogen cyanide .........Hydrogen sulfide ...........Isobutyl alcohol ..............Methomyl ........................Methoxychlor ..................3-Methylcholanthrene ....4,4'-Methylenebls (2-

chloroaniline).Methylene chloride.Methyl ethyl ketone

(MEK).Methyl hydrazine ............Methyl parathion .............Naphthalene ...................Nickel cyanide ................Nitric oxide ......................Nitrobenzene ...................N-Nitrosodl-n-

butylamine.N-Nitrosodiethylamine..N-Nitroso-N-

methylurea.N-Nitrosopyrrolkgne ......

96-12-8

106-46-775-71-8

75-35-4120-83-2542-75-6

60-57-184-66-256-53-160-51-6

121-14-2122-39-4122-66-7115-29-772-20-8

106-89-8106-93-475-21-8

7782-41-464-18-676-44-8

1024-57-3118-74-187-68-377-47-4

19408-74-3

67-72-1302-01-174-90-8

7783-06-478-83-1

16752-77-572-43-556-49-5

101-14-4

75-09-278-93-3

60-34-4298-00-0

91-20-3557-19-7

10102-43-998-95-3

924-16-3

55-18-5

684-93-5

930-65-2

2xE-05

7.5xE-027xE+00

5xE-03IxE-01lxE-032xE-053xE+017xE-073xE-025xE-049xE-015xE-042xE-032xE-044xE-024xE-073xE-044xE+007xE+018xE-054xE-052xE-045xE-032xE-01

6xE-08

3xE-02lxE-047xE - 05lxE-06lxE+01lxE+00IxE-014xE-052xE-03

SxE-022xE+00

3xE-042xE - 02lxE+017xE-014xE+002xE-026xE-05

2xE-06lxE-07

2xE-04

NONMETALS-RESIDUE CONCENTRATIONLiMITS--Continued

Concentra-ton imitsConstituent CAS No. for residues(mg/kg)

Pentachlorobenzene 608-93-6 3xE-02Pentachlorontroben- 82-68-8 ixE-01

zene (PCNB).Pentachloropheno 87-86-5 lxE+00Phenol...-.. .. ..... 108-9-2 1xE+00Phenyfmerculy acetate. 62-38-4 3xE-03Phosphlnen.._............ 7803-51-2 lxE-02Polychlortnated 1336-36-3 5xE-05

biphenyls, N.O.S.Potassium cyande.' 151-50-8 2xE+00Potassium silver 506-61-8 7xE+00

cyanide.Pronamide .................... 23950-58-5 3xE+00Pyridine ........................... 110-86-1 4xE-02Reserpine ...... 50-55-5 3xE-05Selenourea .................... 630-10-4 2xE-01Silver cyanide ............... 506-64-9 4xE+00Sodium cyanide ............ 143-33-9 IxE+00Stychnine ............ 57-24-9 IxE-021,2,4,5- 95-94-3 lxE-02

Tetrachlorobenzene.1,1,2,2- 79-34-5 2xE-03

tetrachloroethane,Tetrchloroethylene 127-18-4 7xE-0123.4,6- 58-90-2 lxE-02

Tetrachlorophenol.Tetraethyl lead ................ 78-00-2 4xE-06Thallium ........................... 7440-28-0 7xE+00Thallic oxide .................. 1314-32-5 2xE-03Thallium(l) acetate 563-68-8 3xE-03Thallium(l) carbonate ..... 6533-73-9 3xE-03Thallium(l) chloride ........ 7791-12-0 3xE-03Thallium(l) nitrate ........... 10102-45-1 3xE-03Thallium selenite ............ 12039-52-0 3xE-03Thallium(l) sulfate ........... 7446-18-6 3xE-03Thioura ..... ...... 62-56-6 2xE-04Toluene ........................... 108-88-3 lxE+01Toxaphene ......... . ..... 8001-35-2 5xE-031,1,2-Trichloroethane.. 79-00-5 6xE-03Trichloroethylene_... 79-01-6 5xE-03Trichloromonofluoro- 75-69-4 lxE+01

methane.2,4,5-Trichlorophenol_ 95-95-4 4xE+002,4.6-Trichioro ei.... 88-06-2 4xE+00Vanadium pentoxide ...... 1314-62-1 7xE-01Vinyl chloride ................. 75-01-4 2xE-03

* Note: The health-based concentrationlimits for Appendix VIII Part 261 constituentsfor which a health-based concentration is notprovided below is 2xE-06 mg/kg.




Appendix VIl.-Potential PICs forDetermination of Exclusion of Waste-Derived Residues

PICs FOUND IN STACK EFFLUENTS

Volatile Semnolatiles

Benzene ........................... Bis(2-ethyrhexyl)phthalate

Toluene ...................... NaphthaleneCarbon tetrachloride .......... Phenotroform .................................. Diethy" phthaiateMethyone chloride ........... uty benzyl phthalateTrichloroethytene ............. 24-DimethylphenoTetrachloroet fene ........... o-Dichlorobenzene1,1.1-Trichloroethane . rn-Dichlorobenzenerobenzene .......... . -Dichlorobenzenecis- 1,4-Dichtoro-2-butene.. HexachlorobenzeneBromochloromethane ........ 2,4-TnchlorophenoBromodictoromethane ..... FluorantheneBromoform .................... o-NitrophenolBronoethane ............. 1.2,4-TrichlorobenzeneMethyleie bromide ........... o-ChlorophenolMethyl ethyl ketone ....... Pentachlorophenol

PyreneDimethyl phthalateMononitrobenzene2,6-Toluene diisocyanate

Appendices IX and X will bepublished in the Federal Register in thenear future. Appendix IX is MethodsManual for Compliance with BIFRegulations, U.S. EPA, December 1990,available from the National TechnicalInformation Service (NTIS), 5285 PortRoyal Road, Springfield, VA 22161. (703)487-4600, document number PB91-120-006. Appendix X is Guideline on AirQuality Models (Revised) (1986), U.S.EPA, including Supplement A (1987),available from NTIS, 5285 Port RoyalRoad, Springfield, VA 22161, documentnumbers PB86-245-248 (Guideline) andPB8&-150-958 (Supplement A).

PART 270-EPA ADMINISTEREDPERMIT PROGRAMS: THEHAZARDOUS WASTE PERMITPROGRAM.

VI. In part 270:1. The authority citation for part 270


Authority: 42 U.S.C. 6905, 6912, 6924. 6925,6927, 6939, and 6974.

2. Part 270 is amended by adding§ 270.22 to read as follows:

§ 270.22 Specific Part 8 informationrequirements for boilers and Industrialfurnaces burning hazardous waste.

(a) Trial burns-(1) General Exceptas provided below, owners andoperators that are subject to thestandards to control organic emissionsprovided by § 266.104 of this chapter,standards to control particulate matterprovided by J 26.105 of this chapter,standards to control metals emissionsprovided by § 266.106 of this chapter, orstandards to control hydrogen chloride

or chlorine gas emissions provided by§ 266.107 of this chapter must conduct atrial burn to demonstrate conformancewith those standards and must submit atrial burn plan or the results of a trialburn, including all requireddeterminations, in accordance with§ 270.66.

(i) A trial burn to demonstrateconformance with a particular emissionstandard may be waived underprovisions of §§ 266.104 through 266.107of this chapter and paragraphs (a)(2)through (a)(5) of this section; and

(ii) The owner or operator may submitdata in lieu of a trial burn, as prescribedin paragraph (a)(6) of this section.

(2) Waiver of trial burn for DRE-(i)Boilers operated under specialoperating requirements. When seekingto be permitted under §§ 266.104(a)(4)and 266.110 of this chapter thitautomatically waive the DRE trial burn,the owner or operator of a boiler mustsubmit documentation that the boileroperates under the special operatingrequirements provided by § 266.110 ofthis chapter.

(ii) Boilers and industrial furnacesburning low risk waste. When seekingto be permitted under the provisions forlow risk waste provided by§§ 266.104(a)(5) and 266.109(a) of thischapter that waive the DRE trial burn,the owner or operator must submit:

(A) Documentation that the device isoperated in conformance with therequirements of § 266.109(a)(1) of thischapter.

(B) Results of analyses of each wasteto be burned, documenting theconcentrations of nonmetal compoundslisted in appendix VIII of part 261 of thischapter, except for those constituentsthat would reasonably not be expectedto be in the waste. The constituentsexcluded from analysis must beidentified and the basis for theirexclusion explained. The analysis mustrely on analytical techniques specifiedin Test Methods for the Evaluation ofSolid Waste, Physical/ChemicalMethods (incorporated by reference, see

260.11).(C) Documentation of hazardous

waste firing rates and calculations ofreasonable, worst-case emission rates ofeach constituent identified in paragraph(a)(l)(ii)(B) of this section usingprocedures provided by§ 266.109(a)(2)(ii) of this chapter.

(D) Results of emissions dispersionmodeling for emissions identified inparagraphs (a)(2)(ii)(C) of this sectionusing modeling procedures prescribedby § 266.106(h) of this chapter. TheDirector will review the emissionmodeling conducted by the applicant todetermine conformance with these

procedures. The Director will eitherapprove the modeling or determine thatalternate or supplementary modeling isappropriate.

(E) Documentation that the maximumannual average ground levelconcentration of each constituentidentified in paragraph (a)(2)(ii)(B) ofthis section quantified in conformancewith paragraph (a)(2)(iilDJ of thissection does not exceed the allowableambient level established in appendicesIV or V of part 266. The acceptableambient concentration for emittedconstituents for which a specificReference Air Concentration his notbeen established in appendix IV or Risk-Specific Dose has not been estahlishedin appendix V is 0.1 micrograms percubic meter, as noted in the footnote toappendix IV.

(3) Waiver of trial burn for metals.When seeking to be permitted under theTier I (or adjusted Tier I) metals feedrate screening limits provided byJ 266.106 (b) and (e) of this chapter thatcontrol metals emissions withoutrequiring a trial burn, the owner oroperator must submit:

(i) Documentation of the feed rate ofhazardous waste, other fuels, andindustrial furnace feed stocks;

(ii) Documentation of theconcentration of each metal controlledby § 266.106 (b) or (e) of this chapter inthe hazardous waste, other fuels, andindustrial furnace feedstocks, andcalculations of the total feed rate ofeach metal;

(iii) Documentation of how theapplicant will ensure that the Tier I feedrate screening limits provided by§ 266.106 (b) or (e) of this chapter willnot be exceeded during the averagingperiod provided by that paragraph;

(iv) Documentation to support thedetermination of the terrain-adjustedeffective stack height, good engineeringpractice stack height, terrain type, andland use as provided by § 266.106 (b)(3)through (b)(5) of this chapter;

(v) Documentation of compliance withthe provisions of J 266.106(b)(6), ifapplicable, for facilities with multiplestacks;

(vi) Documentation that the facilitydoes not fail the criteria provided by§ 266.106(b)(7) for eligibility to complywith the screening limits; and

(vii) Proposed sampling and metalsanalysis Plan for the hazardous waste.other fuels, and industrial furnace feedstocks.

(4) Waiver of trial burn for particulatematter. When seeking to be permittedunder the low risk waste provisions of§ 266.109(b) which w.aives theparticulate standard (and trial burn to

I I I I7235




demonstrate conformance with theparticulate standard), applicants mustsubmit documentation supportingconformance with paragraphs (a)(2)(ii)and (a){3) of this section.

(5] Waiver of trial burn for HCI andCl2. When seeking to be permitted underthe Tier I (or adjusted Tier I) feed ratescreening limits for total chloride andchlorine provided by § 266.107 (b)(1) and(e) of this chapter that control emissionsof hydrogen chloride (HCI) and chlorinegas (Cl2) without requiring a trial bum,the owner or operator must submit:

(i} Documentation of the feed rate ofhazardous waste, other fuels, andindustrial furnace feed stocks;

(ii) Documentation of the levels oftotal chloride and chlorine in thehazardous waste, other fuels, andindustrial furnace feedstocks, andcalculations of the total feed rate of totalchloride and chlorine;

(iii) Documentation of how theapplicant will ensure that the Tier I (oradjusted Tier I) feed rate screeninglimits provided by § 266.107 (b)(1) or (e)of this chapter will not be exceededduring the averaging period provided bythat paragraph;

(vi) Documentation to support thedetermination of the terrain-adjustedeffective stack height, good engineeringpractice stack height, terrain type, andland use as provided by § 266.107(b)(3)of this chapter,

(v) Documentation of compliance withthe provisions of § 266.107(b)(4), ifapplicable, for facilities with multiplestacks;

(vi) Documentation that the facilitydoes not fail the criteria provided by§ 266.107(b)(3) for eligibility to complywith the screening limits; and

(vii) Proposed sampling and analysisplan for total chloride and chlorine forthe hazardous waste, other fuels, andindustrial furnace feestocks.

(6) Data in lieu of trail burn. Theowner or operator may seek anexemption from the trial bumrequirements to demonstrateconformance with § § 266.104 through266.107 of this chapter and § 270.66 byproviding the information required by§ 270.66 from previous compliancetesting of the device in. conformancewith § 266.103 of this chapter, or fromcompliance testing or trial oroperational burns of similar boilers orindustrial furnaces burning similarhazardous wastes under similarconditions. If data from a similar deviceis used to support a trial burn waiver,the design and operating informationrequired by § 270.66 must be providedfor both the similar device and thedevice to which the data is to beapplied, and a comparison of the design

and operating information must beprovided. The Director shall approve apermit application without a trial burn ifhe finds that the hazardous wastes aresufficiently similar, the devices aresufficiently similar, the operatingconditions are sufficiently similar, andthe data from from other compliancetests, trial bums, or operational burnsare adequate to specify (under § 266.102of this chapter) operating conditions thatwill ensure conformance with§ 266.102(c) of this chapter. In addition,the following information shall besubmitted:

(i) For a waiver from any trial burn:(A) A description and analysis of the

hazardous waste to be burned comparedwith the hazardous waste for whichdata from compliance testing, oroperational or trial burns are providedto support the contention that a trialbum is not needed;

(B) The design and operatingconditions of the boiler or industrialfurnace to be used, compared with thatfor which comparative burn data areavailable; and

(C) Such supplemental information asthe Director finds necessary to achievethe purposes of this paragraph.

(ii) For a waiver of the DRE trial bum,the basis for selection of POHCs used inthe other trial or operational burnswhich demonstrate compliance with theDRE performance standard in§ 266.104(a) of this chapter. Thisanalysis should specify the constituentsin appendix VIII, part 261 of thischapter, that the applicant has identifiedin the hazardous waste for which apermit is sought, and any differencesfrom the POHCs in the hazardous wastefor which burn data are provided.

(b) Alternative HC limit for industrialfurnaces with organic matter in rawmaterials. Owners and operators ofindustrial furnaces requesting analternative HC limit under § 266.104(f) ofthis chapter shall submit the followinginformation at a minimum:

(1) Documentation that the furnace isdesigned and operated to minimze HCemissions from fuels and raw materials;

(2) Documentation of the proposedbaseline flue gas HC (and CO)concentration, including data on HC(and CO) levels during tests when thefacility produced normal products undernormal operating conditions fromnormal raw materials while burningnormal fuels and when not burninghazardous waste;

(3) Test burn protocol to confirm thebaseline HC (and CO) level includinginformation on the type and flow rate ofall feedstreams, point of introduction ofall feedstreams, total organic carboncontent (or other appropriate measure of

organic content) of all nonfuelfeedstreams, and operating conditionsthat affect combustion of fuel(s) anddestruction of hydrocarbon emissionsfrom nonfuel sources;

(4) Trial bum plan to:(i) Demonstrate that flue gas HC (and

CO) concentrations when burninghazardous waste do not exceed thebaseline HC (and CO) level; and

(ii) Identify the types andconcentrations of organic compoundslisted in appendix VIII, part 261 of thischapter, that are emitted when burninghazardous waste in conformance withprocedures prescribed by the Director,

(5) Implementation plan to monitorover time changes in the operation of thefacility that could reduce the baselineHC level and procedures to periodicallyconfirm the baseline HC level; and

(6) Such other information as theDirector finds necessary to achieve thepurposes of this paragraph.

(c) Alternative metals implementationapproach. When seeking to be permittedunder an alternative metalsimplementation approach under§ 266.106(f) of this chapter, the owner oroperator must submit documentationspecifying how the approach ensures.compliance with the metals emissionsstandards of § 266.106(c) or (d) and howthe approach can be effectivelyimplemented and monitored. Further,the owner or operator shall provide suchother information that the Director findsnecessary to achieve the purposes ofthis paragraph.

(d) Automatic waste feed cutoffsystem. Owners and operators shallsubmit information describing theautomatic waste feed cutoff system,including any pre-alarm systems thatmay be used.

(e) Direct transfer. Owners andoperators that use direct transferoperations to feed hazardous wastefrom transport vehicles (containers, asdefined in § 266.111 of this chapter)directly to the boiler or industrialfurnace shall submit informationsupporting conformance with thestandards for direct transfer provided by§ 266.111 of this chapter.

(f) Residues. Owners and operatorsthat claim that their residues areexcluded from regulation under theprovisions of § 266.112 of this chaptermust submit information adequate todemonstrate conformance with thoseprovisions.

(Approved by the Office of Managementand Budget under control number 2050-073)

3. In § 270.42, paragraph (g) is revisedto read as follows:




§ 270.42 Permit modification at therequest of the pa.rittee.

(g) Newly regulated wastes and units.(1) The permittee is authorized tocontinue to manage wates listed oridentified as hazardous under part 261of this chapter, or to continue to managehazardous waste in units newlyregulated as hazardous wastemanagement units, if:

(i) The unit was In existence as ahazardous waste facility with respect tothe newly listed or characterized wasteor newly regulated waste managementunit on the effetive date of the final rulelisting or identifying the waste, orregulating the unit

(ii) The permittee submits a Class 1modification request on or before the

date on which the waste or unitbecomes subject to the newrequirements;

(iii) The permittee is in compliancewith the applicable standards of 40 CFRparts 265 and 266 of this chapter,

(iv) In the case of Classes 2 and 3modifications, the permittee alsosubmits a complete modification'requestwithin 180 days of the effective date ofthe rule listing or identifying the waste,or subjecting the unit to RCRA SubtitleC management standards;

(v) In the case of land disposal units,the permittee certifies that each suchunit is in compliance with all applicablerequirements of part 265 of this chapterfor groundwater monitoring andfinancial responsibility on the date 12months after the effective date of the

rule identifying or listing the waste ashazardous, or regulating the unit as ahazardous waste management unit. Ifthe owner or operator fails to certifycompliance with all these requirements,he or she will lose authority to operateunder this section.

(2) New wastes or units added to afacility's permit under this subsection donot constitute expansions for thepurpose of the 25 percent capacityexpansion limit for Class 2modifications.

4. In § 270.42, Appendix I is amendedby revising the heading of L and items 1.4, 5a, 6, 7b, and 8 to read as follows:

Appendix I to Section 270.42-Classifitation of Permit Modifications

Modifications Class

L Incinerators Boilers, and Industrial Furnaces:1. Changes to Increase by more than 25% any of the following limits authorized in the permit: A thermal feed rate limit, a feedstream feed rate limit, a

chorne/chlorlde feed rate limit, a metal feed rate limit, or an ash feed rate limit. The Director wil require a new trial bum to substantiate compliancewith the regulatory performance standards unless this demonstration can be made through other means ......................... 3

2. Changes to Increase by up to 25% any of the following limits authorized in the permit: A thermal feed rate limit, a feedstream feed rate limit, a chlorine/chloride feed rate limit, a metal feed rate limit, or an ash feed rate limit. The Director will require a new trial bum to substantiate compliance with theregulatory performance standards unless this demonstration can be made through other means ............. .... ...................................................... 2

3. Modification of an incinerator, boiler, or industrial furnace unit by changing the internal size or geometry of the primary or secondary combustion units,by adding a primary or secondary combustion unit, by substantially changing the design of any component used to remove HCI/C,, metals, orparticulate from the combustion gases, or by changing other features of the incinerator, boiler, or industrial furnace that could affect Its capability tomeet the regulatory performance standards. The Director will require a new trial bum to substantiate compliance with the regulatory performancestandards unless this demonstration can be made through other mean ..................................................................................................................................... 3

4. Modification of an incinerator, boiler, or industrial furnace unit In a manner that would not likely affect the capability of the unit to meet the regulatoryperfonmance standards but which would change the operating conditions or monitonng requirements specified in the permit. The Director may require anew trial burn to demonstrate compliance with the regulatory performance standards .................................................................................................................... 2

5. Operating reqirmenta. Modification of the limits specified in the permit for minimum or maximum combustion gas temperature, minimum combustion gas residence time,

oxygen concentration in the secondary combustion chamber, flue gas carbon monoxide and hydrocarbon concentration, maximum temperature at theinlet to the particulate matter emission control system, or operating parameters for the air pollution control system. The Director will require a new trialbum to substantiate compliance with the regulatory performance standards unless this demonstration can be made through other means ............................. 3

6. Burnkn different wastes:a If the waste contains a POHC that Is more difficult to bum than authorized by the permit or If burning of the waste requires compliance with different

regulatory performance standards than specified in the perrmt The Director will require a new trial bum to substantiate compliance with the regulatoryperformance standards unless this demonstration can be made through other means .............................................................. ............................................ 3

b. If the waste does not contain a POHC that is more difficult to bum than authorized by the permit and It burning of the waste does not requirecompliance with different regulatory performance standards than specified In the permit ...... ................................... 2

NOTE: See I 270.42(g) for modification procedures to be used for the management of newly listed or identified wastes7. Shakedown and trial bum:

b. Authorization of up to an additional 720 hours of waste burning during the shakedown period for determining operational readiness after construction,w th the prior approval of the Director .......................................................... .................................................... . ................................................ .. I

8. Substitution of an alternative type of nonhazardous waste fuel that Is not specified In the permit ................................................... 1

I Class I modifications requiring prior Agency approval.

5. Part 270 is amended by adding§ 270.66 to read as follows:

§ 270.66 Permits for bolers and Industrialfurnaces burning hazardous waste.

(a) General. Owners and operators ofnew boilers and industrial furnaces(those not operating under the interimstatus standards of § 266.103 of thischapter) are subject to paragraphs (b)through (f) of this section. Boilers andindustrial furnaces operating under theInterim status standards of § 266.103 of

this chapter are subject to paragraph (g)of this section.

(b) Permit operating periods for newboilers and industrialfurnaces. Apermit for a new boiler or industrialfurnace shall specify appropriateconditions for the following operatingperiods:

(1) Pretrial burn period. For the periodbeginning with initial introduction ofhazardous waste and ending withinitiation of the trial bum, and only forthe minimum time required to bring the

boiler or industrial furnace to a point ofoperation readiness to conduct a trialburn, not to exceed 720 hours operatingtime when burning hazardous waste, theDirector must establish in the PretrialBurn Period of the permit conditions,including but not limited to, allowablehazardous waste feed rates andoperating conditions. The Director mayextend the duration of this operationalperiod once, for up to 720 additionalhours, at the request of the applicantwhen good cause is shown. The permit

7237




may be modified to reflect the extensionaccording to § 270.42.

(i) Applicants must submit astatement, with part B of the permitapplication, that suggests the conditionsnecessary to operate in compliance withthe standards of § § 266.104 through266.107 of this chapter during thisperiod. This statement should include, ata minimum, restrictions on theapplicable operating requirementsidentified in § 266.102(e) of this chapter.

(ii) The Director will review thisstatement and any other relevantinformation submitted with part B of thepermit application and specifyrequirements for this period sufficient tomeet the performance standards of§ § 266.104 through 266.107 of thischapter based on his/her engineeringjudgment.

(2] Trial burn period. For the durationof the trial burn, the Director mustestablish conditions in the permit for thepurposes of determining feasibility ofcompliance with the performancestandards of § § 266.104 through 266.107of this chapter and determiningadequate operating conditions under§ 266.102(e) of this chapter. Applicantsmust propose a trial burn plan, preparedunder paragraph (c) of this section, to besubmitted with part B of the permitapplication.

(3) Post-trial burn period. (i) For theperiod immediately followingcompletion of the trial burn, and only forthe minimum period sufficient to allowsample analysis, data computation, andsubmission of the trial bum results bythe applicant, and review of the trialbum results and modification of thefacility permit by the Director to reflectthe trial burn results, the Director willestablish the operating requirementsmost likely to ensure compliance withthe performance standards of § § -66.104through 266.107 of this chapter based onhis engineering judgment.

(ii) Applicants must submit astatement, with part B of the application,that identifies the conditions necessaryto operate during this period incompliance with the performancestandards of § § 266.104 through 266.107of this chapter. This statement shouldinclude, at a minimum, restrictions onthe operating requirements provided by§ 266.102(e) of this chapter.

(iii) The Director will review thisstatement and any other relevantinformation submitted with part B of thepermit application and specifyrequirements for this period sufficient tomeet the performance standards of§ § 266.104 through 266.107 of thischapter based on his/her engineeringjudgment.

(4) Final permit period. For the finalperiod of operation, the Director willdevelop operating requirements inconformance with § 266.102(e) of thischapter that reflect conditions In thetrial bum plan and are likely to ensurecompliance with the performancestandards of § § 266.104 through 107 ofthis chapter. Based on the trial bumresults, the Director shall make anynecessary modifications to the operatingrequirements to ensure compliance withthe performance standards. The permitmodification shall proceed according to§ 270.42.

(c) Requirements for trial burn plans.The trial bum plan must include thefollowing information. The Director, inreviewing the trial bum plan, shallevaluate the sufficiency of theinformation provided and may requirethe applicant to supplement thisinformation, if necessary, to achieve thepurposes of this paragraph:

(1) An analysis of each feed stream,including hazardous waste, other fuels,and industrial furnace feed stocks, asfired, that includes:

(i) Heating value, levels of antimony,arsenic, barium, beryllium, cadmium,chromium, lead, mercury, silver,thallium, total chlorine/chloride, andash;

(ii) Viscosity or description of thephysical form of the feed stream;

(2) An analysis of each hazardouswaste, as fired, including:

(i) An identification of any hazardousorganic constituents listed in appendixVIII, part 261, of this chapter that arepresent in the feed stream, except thatthe applicant need not analyze forconstituents listed in appendix Vm thatwould reasonably not be expected to befound in the hazardous waste. Theconstituents excluded from analysismust be identified and the basis for thisexclusion explained. The analysis mustbe conducted in accordance withanalytical techniques specified in TestMethods for the Evaluation of SolidWaste, Physical/Chemical Methods(incorporated by reference, see § 270.6),or their equivalent.

(ii) An approximate quantification ofthe hazardous constituents identified inthe hazardous waste, within theprecision produced by the analyticalmethods specified in Test Methods forthe Evaluation of Solid Waste, Physical/Chemical Methods (incorporated byreference, see § 270.6), or otherequivalent.

(iii) A description of blendingprocedures, if applicable, prior to firingthe hazardous waste, including adetailed analysis of the hazardouswaste prior to blending, an analysis of

the material with which the hazardouswaste is blended, and blending ratios.

(3) A detailed engineering descriptionof the boiler or Industrial furnace,including:

(i) Manufacturer's name and modelnumber of the boiler or industrialfurnace;

(ii) Type of boiler or industrialfurnace;

(ii) Maximum design capacity inappropriate units;

(iv) Description of the feed system forthe hazardous waste, and, asappropriate, other fuels and industrialfurnace feedstocks;

(v) Capacity of hazardous waste feedsystem;

(vi) Description of automatichazardous waste feed cutoff system(s);and

(vii) Description of any pollutioncontrol system; and

(viii) Description of stack gasmonitoring and any pollution controlmonitoring systems.

(4) A detailed description of samplingand monitoring procedures includingsampling and monitoring locations in thesystem, the equipment to be used,sampling and monitoring frequency, andplanned analytical procedures forsample analysis.

(5) A detailed test schedule for eachhazardous waste for which the trial burnis planned, including date(s), duration,quantity of hazardous waste to beburned, and other factors relevant to theDirector's decision under paragraph(b)(2) of this section.

(6) A detailed test protocol, including,for each hazardous waste identified, theranges of hazardous waste feed rate,and, as appropriate, the feed rates ofother fuels and industrial furnacefeedstocks, and any other relevantparameters that may affect the ability ofthe boiler or industrial furnace to meetthe performance standards in § § 266.104through 266.107 of this chapter.

(7) A description of, and plannedoperating conditions for, any emissioncontrol equipment that will be used.

(8) Procedures for rapidly stopping thehazardous waste feed and controllingemissions in the event of an equipmentmalfunction.

(9) Such other information as theDirector reasonably finds necessary todetermine whether to approve the trialbum plan in light of the purposes of thisparagraph and the criteria in paragraph(b)(2) of this section.

(d) Trial burn procedures. (1) A trialburn must be conducted to demonstrateconformance with the standards of§ § 266.104 through 266.107 of this




chapter under an approved trial burnplan.

(2) The Director shall approve a trialburn plan if he/she finds that:

(i) The trial burn is likely to determinewhether the boiler or industrial furnacecan meet the performance standards of§ § 266.104 through 266.107 of thischapter

(ii) The trial burn itself will notpresent an imminent hazard to human

.health and the environment;(iii) The trial burn will help the

Director to determine operatingrequirements to be specified under§ 266.102(e) of this chapter and

(iv) The information sought in the trialburn cannot reasonably be developedthrough other means.

(3) The applicant must submit to theDirector a certification that the trialbum has been carried out in accordancewith the approved trial bum plan, andmust submit the results of all thedeterminations required in paragraph (c)of this section. This submission shall bemade within 90 days of completion ofthe trial bum, or later if approved by theDirector.

(4) AlU data collected during any trialburn must be submitted to the Directorfollowing completion of the trial burn.

(5) All submissions required by thisparagraph must be certified on behalf ofthe applicant by the signature of aperson authorized to sign a permitapplication or a report under § 270.11.

(e) Special procedures for DRE trialburns. When a DRE trial bum isrequired under § 266.104(a) of thischapter, the Director will specify (basedon the hazardous waste analysis dataand other information in the trial bumplan) as trial Principal OrganicHazardous Constituents (POHCs) thosecompounds for which destruction andremoval efficiencies must be calculatedduring the trial burn. These trial POHCswill be specified by the Director basedon information including his/herestimate of the difficulty of destroyingthe constituents identified in thehazardous waste analysis, theirconcentrations or mass in the hazardouswaste feed, and, for hazardous wastecontaining or derived from wastes listedin part 261, subpart D of this chapter, thehazardous waste organic constituent(s)identified in Appendix VII of that partas the basis for listing.

(f) Determinations based on trialburn. During each approved trial burn(or as soon after the bum as Ispracticable), the applicant must makethe following determinations:

(1) A quantitative analysis of thelevels of antimony, arsenic, barium,beryllium, cadmium, chromium, lead,mercury, thallium, silver, and chlorine/

chloride, in the feed streams (hazardouswaste, other fuels, and industrialfurnace feedstocks);

(2) When a DRE trial burn Is requiredunder § 266.104(a) of this chapter:

(i) A quantitative analysis of the trialPOHCs in the hazardous waste feed:

(ii) A quantitative analysis of thestack gas for the concentration andmass emissions of the trial POHCs; and

(iii) A computation of destruction andremoval efficiency (DRE), in accordancewith the DRE formula specified in§ 266.104(a) of this chapter;,

(3) When a trial burn for chlorinateddioxins and furans is required under§ 266.104(e) of this chapter, aquantitative analysis of the stack gas forthe concentration and mass emissionrate of the 2,3,7,8-chlorinated tetra-octacongeners of chlorinated dibenzo-p-dioxins and furans, and a computationshowing conformance with the emissionstandard.

(4) When a trial burn for particulatematter, metals, or HCl/Ch is requiredunder § § 266.105, 266.106 (c) or (d), or266.107 (b)(2) or (c) of this chapter, aquantitative analysis of the stack gas forthe concentrations and mass emissionsof particulate matter, metals, orhydrogen chloride (HCl) and chlorine(C), and computations showingconformance with the applicableemission performance standards;

(5) When a trial bum for DRE, metals,or HCI/C2 is required under§ § 266.104(a), 266.106 (c) or (d), or266.107 [b)(2) or (c) of this chapter, aquantitative analysis of the scrubberwater (if any), ash residues, otherresidues, and products for the purposeof estimating the fate of the trial POHCs,metals, and chlorine/chloride;

(6) An identification of sources offugitive emissions and their means ofcontrol;

(7) A continuous measurement ofcarbon monoxide (CO), oxygen, andwhere required, hydrocarbons (HC), inthe stack gas; and

(8) Such other information as theDirector may specify as necessary toensure that the trial bum will determinecompliance with the performancestandards is § § 266.104 through 266.107of this chapter and to establish theoperating conditions required by§ 266.102(e) of this chapter as necessaryto meet those performance standards.

(g) Interim status boilers andindustrialfurnaces. For the purpose ofdetermining feasibility of compliancewith the performance standards of§ 1266.104 through 266.107 of thischapter and of determining adequateoperating conditions under § 266.103 ofthis chapter, applicants owning oroperating existing boilers or industrial

furnaces operated under the interimstatus standards of § 266.103 must eitherprepare and submit a trial burn plan andperform a trial bum in accordance withthe requirements of this section orsubmit other information as specified in§ 270.22(a)(6). Applicants who submit atrial burn plan and receive approvalbefore submission of the part B permitapplication must complete the trial burnand submit the results specified inparagraph (9 of this section with thepart B permit application. If completionof this process conflicts with the dateset for submission of the part Bapplication, the applicant must contactthe Director to establish a later date forsubmission of the part B application orthe trial burn results. If the applicantsubmits a trial burn plan with part B ofthe permit application, the trial burnmust be conducted and the resultssubmitted within a time period prior topermit issuance to be specified by theDirector.

(Approved by the Office of Managementand Budget under control number 2050-0073)

6. § 270.72 is amended by addingparagraphs (a)(6) and (b)(7) to read asfollows:

§ 270.72 Changes during Interim status.

(a) * * *(6) Addition of newly regulated units

for the treatment, storage, or disposal ofhazardous waste if the owner oroperator submits a revised part A permitapplication on or before the date onwhich the unit becomes subject to thenew requirements.(b) * * *

(7) Addition of newly regulated unitsunder paragraph (a)(6) of this section.

7. § 270.73 is amended by revisingparagraphs (f) and (g) to read as follows:

§270.73 Termination of Interim status.

(f) For owners and operators of eachincinerator facility which as achievedinterim status prior to November 8, 1984,interim status terminates on November8, 1989, unless the owner or operator ofthe facility submits a part B applicationfor a RCRA permit for an incineratorfacility by November 8, 1986.

(g) For owners or operators of anyfacility (other than a land disposal or anincinerator facility) which as achievedinterim status prior to November 8, 1984,interim status terminates on November8, 1992, unless the owner or operator ofthe facility submits a part B applicationfor a RCRA permit for the facility byNovember 8, 1988.

7239




PART 271-REQUIREMENTS FOR 1. The authority citation for part 271 chronological order by date ofAUTHORIZATION OF STATE continues to read as follows: promulgation in the Federal Register.HAZARDOUS WASTE PROGRAMS Authority: 42 U.S.C. 6905,6912(a), and 6926. § 271.1 Purpose and scope.

VII. In part 271: 2. Section 271.10) is amended by * *adding the following entry to Table In 0) * *

TABLE I.-REGULATIONS IMPLEMENTING THE HAZARDOUS AND SOLID WASTE AMENDMENTS OF 1984

Promulgation date Title of regulation Fedral Register Effective datereference

December 31, 1990...... Burning of Hazardous Waste In Boilers and Industial Furnaces .......................... (insert FR page August 21, 1991.numbers].

[FR Doc. 91-2667 Filed 2-20-91; 8:45 am]BILMNG COOE 6660-60-A



7134 federal register vol. no. thursday, february 21, 1991 ...€¦ · preregistration is required...

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