I

I

I

FEASIBILITY STUDY REPORT

BLOSENSK! LANDFILL SITECHESTER COUNTY, PENNSYLVANIA

EPA WORK ASSIGNMENT. NUMBER 37-3L49.0I CONTRACT NUMBER 68-01-6699

NUS PROJECT NUMBER S759

FEBRUARY 1986

SUBMITTED FOR NUS BY: APPROVED:

Park West TwoCliff Mine RoadPittsburgh, PA 15275

___ COF=iPC)RATION 4i2-788-ioso

• D - 3 4 - 1 - 6 - 2DRAFT

* BL- n -FS-D(2)-I

(CHUT?

GEORGE V. GARTSEFF DAVID E. MaclNTYRE, P.E.PROJECT MANAGER REGIONAL MANAGER

REGION III

A Halliburton Company

DRAFT

CONTENTS

SECTION PAGE

EXECUTIVE SUMMARY ES-1

1.0 INTRODUCTION * -11.1 SITE BACKGROUND -11.2 REMEDIAL INVESTIGATION RESULTS -41.2.1 CONTAMINANTS . -41.2.2 PATHWAYS AND RECEPTORS -151.2.3 PUBLIC HEALTH AND ENVIRONMENTAL RISKS -161.3 REMEDIAL ACTION OBJECTIVES AND CRITERIA 1-211.3.1 CONTAMINATED GROUNDWATER 1-221.3.2 CONTAMINATED SURFACE SOILS AND SEDIMENTS 1-241.3.3 RESPIRABLE CONTAMINANTS 1-251.4 FEASIBILITY STUDY PROCEDURE 1-28

2.0 SCREENING OF REMEDIAL ACTION TECHNOLOGIES 2-12.1 SCREENING CRITERIA . 2-12.1.1 SATISFACTION OF REMEDIAL ACTION OBJECTIVES 2-12.1.2 TECHNICAL FEASIBILITY 2-22.1.3 HEALTH AND ENVIRONMENTAL IMPACTS 2-22.1.4 COST EVALUATION 2-32.1.5 INSTITUTIONAL CONSIDERATIONS 2-32.2 CANDIDATE GENERAL RESPONSE ACTIONS 2-3

AND TECHNOLOGIES2.3 TECHNOLOGY SCREENING PROCESS 2-32.3.1 NO ACTION WITH MONITORING 2-52.3.2 CONTAINMENT 2-52.3.3 GROUNDWATER COLLECTION 2-142.3.4 SURFACE WATER CONTROLS 2-162.3.5 CONTAMINANT EXCAVATION/REMOVAL 2-162.3.6 INNOVATIVE TREATMENT TECHNOLOGIES 2-162.3.7 GROUNDWATER TREATMENT 2-182.3.8 ONSITE STORAGE 2-212.3.9 ONSITE DISPOSAL 2-212.3.10 OFFSITE DISPOSAL 2-232.3.11 ALTERNATE WATER SUPPLY 2-242.4 FEASIBLE REMEDIAL ACTION TECHNOLOGIES 2-25

3.0 DEVELOPMENT OF REMEDIAL ACTION 3-1ALTERNATIVES

3.1 PURPOSE OF THE ALTERNATIVES 3-13.2 PROCEDURES FOR ALTERNATIVE DEVELOPMENT 3-13.3 LEVELS OF REMEDIATION TO BE ACHIEVED 3-23.4 FORMULATION OF REMEDIAL ACTION 3-4

ALTERNATIVES

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CONTENTS (CONTINUED)

SECTION

, 3.4.1 NO ACTION 3-43.4.2 ALTERNATIVES THAT MEET CERCLA GOALS 3-4

' BUT DO NOT ATTAIN OTHER APPLICABLEOR RELEVANT STANDARDS

! 3.4.3 ALTERNATIVES THAT ATTAIN APPLICABLE OR 3-5I RELEVANT PUBLIC HEALTH OR ENVIRONMENTAL

STANDARDS, GUIDANCE, OR ADVISORIESi 3.4.4 ALTERNATIVES THAT EXCEED APPLICABLE OR 3-7I RELEVANT PUBLIC HEALTH AND ENVIRONMENTAL

STANDARDS, GUIDANCE, AND ADVISORIES3.4.5 ALTERNATIVES SPECIFYING OFFSITE STORAGE, 3-8

DESTRUCTION, TREATMENT, OR SECURE1 DISPOSAL OF HAZARDOUS SUBSTANCES AT A

FACILITY APPROVED UNDER RCRA] 3.5 SUMMARY OF ALTERNATIVE DEVELOPMENT 3-9

4.0 EVALUATION OF REMEDIAL ACTION ALTERNATIVES 4-14.1 EVALUATION CRITERIA 4-14.1.1 TECHNICAL EVALUATION 4-14.1.2 PUBLIC HEALTH AND ENVIRONMENTAL EVALUATION 4-24.1.3 INSTITUTIONAL EVALUATION 4-24.1.4 COST EVALUATION 4-24.2 EVALUATION OF ALTERNATIVES PROVIDING NO 4-5

REMEDIAL ACTION4.2.1 REMEDIAL ACTION ALTERNATIVE ONE - NO ACTION 4-5

WITH LONG-TERM MONITORING4.3 EVALUATION OF ALTERNATIVES THAT MEET CERCLA 4-10

GOALS BUT DO NOT ATTAIN OTHER APPLICABLE STANDARDS4.3.1 REMEDIAL ACTION ALTERNATIVE TWO -ONSITE 4-10

CAPPING OF CONTAMINATED SOILS AND WASTES;EXTENSION OF THE COATESVILLE WATER AUTHORITYPUBLIC WATER SUPPLY; AND LONG-TERM MONITORING

4.4 EVALUATION OF ALTERNATIVES THAT ATTAIN ALL 4-21APPLICABLE OR RELEVANT STANDARDS, GUIDANCE,OR ADVISORIES

4.4.1 REMEDIAL ACTION ALTERNATIVE THREE- ONSITE 4-21MULTIMEDIA CAPPING OF CONTAMINATED SOILS ANDWASTES; EXTENSION OF THE COATESVILLE WATER AUTHORITYPUBLIC WATER SUPPLY; GROUNDWATER EXTRACTION,TREATMENT, AND INJECTION; AND LONG-TERMMONITORING

ill 302040

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' '"'• CONTENTS (CONTINUED)

SECTION PAGE

4.4.2 REMEDIAL ACTION ALTERNATIVE FOUR - CONSTRUCTION 4-38OF A SECURED ONSITE LANDFILL; EXTENSIONOF THE COATESVILLE WATER AUTHORITY PUBLICWATER SUPPLY; GROUNDWATER EXTRACTION, TREATMENT,AND INJECTION; AND LONG-TERM MONITORING

4.5 EVALUATION OF ALTERNATIVES THAT EXCEED 4-48APPLICABLE OR RELEVANT PUBLIC HEALTH ANDENVIRONMENTAL STANDARDS, GUIDANCE, ANDADVISORIES

4.5.1 REMEDIAL ACTION ALTERNATIVE FIVE—COMPLETE 4-48EXCAVATION OF CONTAMINATED SOILS AND WASTES;ONSITE INCINERATION WITH MULTIMEDIA CAP OVERRESIDUALS; EXTENSION OF THE COATESVILLE WATERAUTHORITY PUBLIC WATER SUPPLY: GROUNDWATEREXTRACTION, TREATMENT, AND INJECTION; ANDLONG-TERM GROUNDWATER MONITORING

4.5.2 OPTION TO REMEDIAL ACTION ALTERNATIVE FIVE— 4-58COMPLETE EXCAVATION OF CONTAMINATED SOILS ANDWASTES; ONSITE INCINERATION WITH STABILIZATIONOF RESIDUALS; EXTENSION OF THE COATESVILLE WATERAUTHORITY PUBLIC WATER SUPPLY; GROUNDWATEREXTRACTION, TREATMENT AND INJECTION;AND LONG-TERM GROUNDWATER MONITORING

4.6 EVALUATION OF ALTERNATIVES SPECIFYING OFFSITE 4-60STORAGE, DESTRUCTION, TREATMENT, OR SECUREDISPOSAL AT A FACILITY APPROVED UNDER RCRA

4.6.1 REMEDIAL ACTION ALTERNATIVE SIX—EXCAVATION 4-60OF CONTAMINATED WASTE DEPOSITS AND DISPOSAL INAN OFFSITE RCRA-APPROVED LANDFILL; THE OPTIONTO DISPOSE, CONTAIN, OR TREAT THE CONTAMINATEDSOILS THAT UNDERLIE THE WASTE DEPOSITS;EXTENSION OF THE COATESVILLE WATER AUTHORITYPUBLIC WATER SUPPLY; GROUNDWATER EXTRACTIONTREATMENT, AND INJECTION; AND LONG-TERM MONITORING

5.0 SUMMARY OF REMEDIAL ACTION 5-1ALTERNATIVES

IV

DRAFT

CONTENTS (CONTINUED}

APPENDICES

A BACKGROUND DATA AND CALCULATIONS FOR TECHNOLOGYSCREENING

CAPPINGGROUT CURTAININCINERATIONINNOVATIVE AND EMERGING TECHNOLOGIESALTERNATE WATER SUPPLY

B BACKGROUND DATA AND CALCULATIONS FORALTERNATIVE EVALUATION

GROUNDWATER EXTRACTION AND TREATMENTONSITE AND OFFSITE LANDFILLSEROSION AND SEDIMENT CONTROLSITE PREPARATIONONSITE INCINERATIONTVOC CALCULATION FOR SOILS

COST EVALUATION

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TABLES

NUMBER PAGE

ES-1 COSTS OF REMEDIAL ACTION ALTERNATIVES ($ 1000s) ES-61-1 CONTAMINANTS AT THE BLOSENSKI LANDFILL SITE 1-61-2 ESTIMATED CARCINOGENIC RISK ASSOCIATED WITH

INGESTION OF GROUNDWATER 1-181-3 PROPOSED GROUNDWATER TREATMENT STANDARDS 1-231-4 SUMMARY OF REMEDIAL ACTION OBJECTIVES

AND GENERAL RESPONSE ACTIONS 1-262-1 GENERAL RESPONSE ACTIONS AND ASSOCIATED 2-4

REMEDIAL TECHNOLOGIES2-2 SUMMARY OF REMEDIAL TECHNOLOGY 2-26

SCREENING PROCESS FOR THEBLOSENSKI LANDFILL bITE

3-1 CATEGORIES OF REMEDIAL ACTION 3-3ALTERNATIVES

4-1 ALTERNATIVES TO PROPOSED INCINERATION SYSTEM ($ 1000s) 4-555-1 REMEDIAL ACTION ALTERNATIVE TRADE-OFF 5-2

MATRIX5-2 REMEDIAL ACTION ALTERNATIVES COST 5-11

SUMMARY ($1,000)

VI 302043

FIGURES

'"'•tt/;..V-

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NUMBER PAGE

1-1 LOCATION MAP 1-21-2 SITE LAYOUT 1-34-1 PROPOSED LONG-TERM MONITORING SAMPLE LOCATIONS 4-84-2 APPROXIMATE LIMITS OF CAPPING 4 4-124-3 TYPICAL SOIL CAP 4-164-4 TYPICAL MULTIMEDIA CAP 4-234-5 PROPOSED GROUNDWATER PUMPING AND INJECTION 4-26

WELL LOCATIONS4-6 TYPICAL PUMPING WELL 4-284-7 GROUNDWATER TREATMENT SYSTEM-METALS REMOVAL 4-304-8 GROUNDWATER TREATMENT SYSTEM-ORGANICS 4-32

REMOVAL4-9 PLAN OF PROPOSED ONSITE LANDFILL 4-414-10 APPROXIMATE CROSS SECTION A-A' PROPOSED 4-42

ONSITE LANDFILL4-11 LANDFILL CAP AND BOTTOM LINER DETAILS 4-434-12 GENERAL ARRANGEMENT FOR ONSITE INCINERATION 4-514-13 PROCESS FLOW DIAGRAM FOR ONSITE ROTARY KILN 4-52

INCINERATION OF SOLID WASTE4-14 APPROXIMATE LIMITS OF PARTIAL EXCAVATION 4-63

VII 302044

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EXECUTIVE SUMMARY

1 The Feasibility Study (FS) Report for the Blosenski Landfill Site has been preparedat the request of the United States Environmental Protection Agency (EPA)

1 Region III under Work Assignment Number 37-3L49.0, Contract Number68-01-6699. This study was prepared in accordance with the requirements of the

[ National Oil and Hazardous Substances Contingency Plan (NCP) published pursuantto Section 105 of the Comprehensive Environmental Response, Compensation, and

j Liability Act of 1980 (CERCLA).

ISite Background

The Blosenski Landfill Site is located on 13.6 acres in West Cain Township, ChesterCounty, Pennsylvania. It is surrounded by heavily wooded areas to the north andwest, and by agricultural areas to the east and northwest. Approximately30 residents live within a quarter-mile radius of the site.

The landfill was reportedly operated for the disposal of municipal and industrialwastes, beginning in the late 1940s. However, there is no specific informationregarding activities at the site until its purchase by Joseph M. Blosenski, Jr., in the1960s. From that time, until operations ceased in 1979, wastes accepted at thesite for disposal included drummed industrial wastes, truckloads of sludge, andmunicipal and commercial refuse. Wastes were not segregated, and the siteapparently was not lined.

Seven permits to operate the landfill were applied for in the 1970s but nevergranted. Several regulatory actions against the owner were issued by thePennsylvania Department of Environmental Resources (PADER). A consent decreeissued in 1979 to force site closure required the completion of groundwater and soilstudies and remedial measures. In accordance with this, four monitoring wellswere installed on site by PADER in 1982. During the winter of that year, 50 to60 drums and a leaking tank truck were removed from the site. Samples

ES-1 302046

DRAFT

taken by PADER and the USEPA Region III Field Investigation Team (FIT) haveidentified soil, surface water, and groundwater contamination with both organicand inorganic substances. These findings were verified by the results of the morerecent remedial investigation (Rl) performed at the site for the USEPA. Thefindings are discussed further in the following section.

A

Remedial Investigation Results

The Rl was performed from the Fall of 1984 through the Spring of 1985 to assessthe present and potential impacts of site-related contamination on the publichealth and the environment, and to provide a technical basis for developingappropriate alternative remedial actions for the site.

The Rl reported that numerous organic and inorganic contaminants were detectedin environmental media at the site. Regional data and site-specific observationsindicate groundwater flow at the site is primarily through bedrock, although alocalized, perched water table was identified in the eastern portion of the site.Volatile organic chemicals, the primary contaminants, have entered the watertable and migrated beyond site boundaries. Advection of volatile contaminantsoccurs through regions of secondary permeability (fractures, faults, and beddingplanes) in the underlying bedrock. The majority of volatile contaminants in thegroundwater regime are migrating to the north of the site, reflecting the hydraulicgradient. It appears that these contaminants are then transported to the northwestvia groundwater flow in a transmissive zone lying beneath the intermittenttributary to Indian Spring Run. Volatile organics were not detected in groundwatersamples obtained to the north of this zone.

Chlorinated aliphatic compounds (primarily trichloroethene and1,1,1-trichloroethane) were consistently detected in residential wells located tothe south of the site. Factors that may induce migration of chemicals to theresidential wells include the location of the source, the location and orientation offractures, the densities of contaminants, hydraulic influences attributable toresidential well pumping, and the depths of residential wells. The most probable

302047ES-2

DRAFT

source of the residential well contaminants lies in the vicinity of MW 2-1 on thesouthern portion of the site.

Two other sources of groundwater contaminants were identified: on the west side,near MW 3-1 (monocyclic aromatics); and on the east near TP-11 (monocyclicaromatics and chlorinated aliphatics).

*

Although detected at the site, semivolatiles, pesticides, PCBs, and inorganicsubstances are not migrating beyond the site boundaries. These relativelyimmobile chemicals appear to be confined to the immediate vicinity of thedeposition areas.

Feasibility Study Objectives and Criteria

The overall purpose of the FS process is to provide an array of technically sound,cost-effective remedial action alternatives (RAAs) that control the source andmanage the migration of contaminants, and provide protection to the public health,welfare, and the environment. In accordance with this, various cleanup objectivesand criteria were established to provide a focus for the general response actionsand technologies available for remediating the Blosenski Landfill Site. Theseobjectives and criteria include

______Cleanup Objectives______ _______Cleanup Criteria___________

a. No action a. Establish current potential risklevels and take no remedial action

b. Prevent an increase in the current b. Establish current potential riskpotential risk associated with the levels and utilize remedial tech-site nologies to prevent an increase in

potential risk levels

302048ES-3

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______Cleanup Objectives______ ______Cleanup Criteria _______

c. Reduce the current potential risk c. Reduce the current potential riskassociated with the site to associated with the site to aacceptable levels target cleanup criteria of a 10~6

potential risk level, or otheracceptable level.

i

d. Reduce the risk levels to those d. Utilize remedial technologiescorresponding to background to eliminate site contaminantsconcentrations

Screening of Remedial Action Technologies

Based on the above objectives and criteria, numerous source control and migrationcontrol technologies were screened to provide a limited number of technologiesapplicable for remedial actions at the site. Some of these technologies wereremoved from further consideration based on site-specific information gatheredduring the Rl and on the basis of other comparative criteria. These other criteriainclude

• Technical performance• Magnitude of costs• Health and environmental impacts• Institutional considerations

Applicable technologies identified during the Rl, as well as those encompassingimportant treatment or disposal options, were discussed and evaluated. If thetechnology was found to be inapplicable for site-specific conditions or use, or if itwas rejected on the basis of other criteria, it was dropped from furtherconsideration. The remaining technologies were developed into candidatealternatives that meet the specific remedial action objectives and the criteria forevaluation of alternatives.

ES-4

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Development and Evaluation of Remedial Action Alternatives

To evaluate a wide range of remedial responses to this site, alternatives weredeveloped to fall into one of five cleanup categories, which are described in theUSEPA Guidance Document on Feasibility Studies Under CERCLA (EPA,June 1985). Each category represents a different degree of site remediation and isdescribed as follows:

• No action.

• Alternatives that meet the CERCLA goals of preventing or minimizingpresent or future migration of hazardous substances and protecting humanhealth and the environment, but do not attain all other applicable orrelevant standards.

• Alternatives that attain all applicable or relevant public health andenvironmental standards, guidance, or advisories.

* • Alternatives that exceed all applicable or relevant public health and. environmental standards, guidance, and advisories.I

• Alternatives specifying offsite storage, destruction, treatment or secureI disposal of hazardous substances at a facility approved under the

Resource Conservation and Recovery Act (RCRA). Such a facility must1 also be in compliance with all other applicable EPA standards.

The following paragraphs provide brief descriptions of the RAAs developed foreach category. Table ES-1 summarizes the capital and present-worth cost foreach RAA.

ES-5 302050

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TABLE ES-1

COSTS OF REMEDIAL ACTION ALTERNATIVES ($ 1000s)

30-YearCapital Present Worth

___Remedial Action Alternative____ Costs (Range) Analysis (Range)

1. No action with monitoring $80-130 ' $1,953-2,003

2. Soil cap, alternate water supply 2,706 - 4,812 5,122 - 7,233and long-term monitoring.

3. Multimedia cap, alternate water 8,481 - 13,037 13,150 - 17,706supply, groundwater extraction andtreatment, and long-term monitoring.

4. Onsite landfill, alternate water 14,317 - 31,508 18,986 - 36,177supply, groundwater extractionand treatment, and long-termmonitoring.

.5a. Onsite incineration, multimedia 26,113 - 32,207 47,858 - 53,952cap, alternate water supply,groundwater extraction andtreatment, and long-term monitoring.

5b. Onsite incineration, stabilization 30,378 - 43,258 53,392 - 66,272of residuals, alternate watersupply, groundwater extraction andtreatment, and long-term monitoring.

6. Excavation and off site disposal ofwastes in a RCRA-approved landfill,alternate water supply, groundwaterextraction and treatment, and long-term monitoring, including thefollowing:

Option a: Excavation and off site 89,388 - 257,503 93,858 - 261,973disposal of soils in a RCRA-approved landfill

Option b: Construct'on of multi- 44,815 - 123,782 49,484 - 128,451media cap over contaminated soils

Option c: Excavation and 45,756 - 126,006 50,027 - 130,877detoxification of contaminatedsoils

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No Action Alternative

Remedial Action Alternative One - No Action with Long-term Monitoring

This is a baseline alternative to provide a comparison of the effectiveness of theother remedial alternatives against present and potential site risks, if the siteremains remediated. Long-term monitoring is proposed as a means to detect anyfuture changes in site conditions or contaminant migration.

Alternatives that Meet CERCLA Goals

Remedial Action Alternative Two - Onsite Capping of Contaminated Soils andWastes; Extension of the Coatesville Water Authority Public Water Supply; andLong-term Monitoring

RAA Two involves leaving the existing contaminated wastes and soils in place,while covering them with a low permeability soil cap to reduce infiltration andprevent dermal contact. An alternate water supply will be provided to potentiallyaffected residences by extending the Coatesville Water Authority's main line.Additional monitoring wells will be installed on site to detect any futurecontaminant migration via the groundwater.

Alternatives That Attain All Applicable Standards

Remedial Action Alternative Three - Onsite Multimedia Capping of ContaminatedSoils and Wastes: Extension of the Coatesville Water Author ty Public WaterSupply; Groundwater Extraction, Treatment, and Injection; and Long-termMonitoring

RAA Three is similar to RAA Two in that all site materials are left in place.However, a multimedia cap of 10"̂ cm/sec permeability material plus a syntheticmembrane is used in lieu of a soil cap. Groundwater extraction, treatment (via airstripping and carbon adsorption), and injection is added to remediate thegroundwater. An alternate water supply and long-term monitoring are alsoprovided in RAA Three.

302052ES-7

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Remedial Action Alternative Four - Construction of a Secured Onsite Landfill:Extension of the Coatesville Water Authority Public Water Supply; GroundwaterExtraction, Treatment and Injection; and Long-term Monitoring

RAA Four involves excavating the approximately 400,000 cubic yards ofcontaminated soil and waste material, constructing a RCRA-approved landfill, andredepositing the materials on site. This alternative would thus completelyencapsulate all contaminated materials and effectivefy isolate them from theenvii^nment. An alternate water supply, groundwater remediation, and long-termmonitoring will be provided.

Alternatives That Exceed All Applicable Standards

Remedial Action Alternative Five - Complete Excavation of Contaminated Soilsand Wastes; Onsite Incineration with Multimedia Cap Over Residuals; Extension ofthe Coatesville Water Authority Public Water Supply; Groundwater Extraction.Treatment and Injection: and Long-term Monitoring

RAA Five, like the previous alternatives, also involves complete excavation ofcontaminated materials. Prior to disposal on site, however, all wastes and soils areincinerated onsite using a mobile, rotary kiln system. Residual materials arebackfilled, and a multimedia cap is placed over them to minimize infiltration. Allorganic contaminants in the soils and wastes will be destroyed via this process. Analternate water supply, groundwater remediation, and long-term monitoringcomplete this remedial action alternative.

Option to Remedial Action Alternative Five____Complete Excavation ofContaminated Soils and Wastes: Onsite Incineration with Stabilization ofResiduals; Extension of the Coatesville WaterGroundwater Extraction, Treatment, and Injection;

Authority Public Waterarrd Long-term Monitoring

Supply;

The option of stabilizing the incinerator residuals instead of placing them under amultimedia cap is also evaluated. A pozzolanic process using flyash and cement asadditives is suggested for stabilization of the metals-laden residuals. Thestabilized product would be backfilled on site, covered with a flow zone andtopsoil, and vegetated. As in the first incineration alternative, an alternate watersupply, groundwater remediation, and long-term monitoring will be provided.

ES-8 302053

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Alternatives That Specify Offsite Disposal

Remedial Action Alternative Six - Excavation of Contaminated Waste Deposits andDisposal in an Offsite RCRA-Approved Landfill; the Option to Dispose, Contain, orTreat the Contaminated Soils that Underlie the Waste Deposits; Extension of theCoatesville Water Authority Public Water Supply; Groundwater Extraction.Treatment, and Injection; and Long-term Monitoring

*

RAA Six provides for excavation and off site disposal of the site's waste materialsin a secure, hazardous waste landfill. Three options are then provided for thecontaminated soils underlying the wastes. In the first option, the soils are disposedoff site, and the area backfilled with clean fill and revegetated. The second optionprovides for a multimedia cap over the in-place soils to reduce the amount ofinfiltration. The third option allows for a series of studies to evaluate thepotential use of an innovative or emerging technology to detoxify the soils using amobile soil washing system. The cleansed soils would be returned to the site asclean backfill and the cleaning fluids treated as necessary. For all three of theseoptions, an alternate water supply, groundwater remediation, and long-termmonitoring are provided.

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II

DRAFT

1.0 INTRODUCTION

1.1 Site Background

The Blosenski Landfill Site occupies approximately 13.6 acres in West CainTownship, Chester County, Pennsylvania. As shown in Figures 1-1 and 1-2, thelandfill lies approximately 1000 feet north of State Route 340 (Kings Highway) ̂nd2000 feet west of the intersection of King's Highway and Cambridge Road. It issurrounded by heavily-wooded areas to the north and to the west, and byagricultural areas to the east and northwest. A marshy area lies on thenortheastern section of the site, and a ravine borders the site to the north and east.Approximately 500 feet north of the site, an intermittent tributary flowswestward, about 2 miles, to Indian Spring Run. About 3.5 miles west of the site.Indian Spring Run joins Pequea Creek, which flows into the Susquehanna Riverapproximately 30 miles southwest of the site. Approximately 30 residents livewithin a quarter-mile radius of the site.

Beginning in the late 1940s, the landfill was reportedly operated by Perry Phillipsfor the disposal of municipal and industrial wastes. However, there is no specificinformation regarding activities at the site until its purchase byJoseph M. Blosenski, Jr., in the 1960s. From that time, until operations ceased in1979, wastes accepted at the site for disposal included drummed industrial wastes,truckloads of sludges, and municipal and commercial refuse. Wastes were notsegregated, and the site apparently was not lined.

Seven permits to operate the landfill were applied for in the 1970s but nevergranted. Several regulatory actions against the owner were issued by thePennsylvania Department of Environmental Resources (PADER). A consent decreeissued in 1979 to force site closure required the completion of groundwater and soilstudies and remedial measures. In accordance with this, four monitoring wellswere installed on site by PADER in 1982. During the winter of that year, 50 to 60drums and a leaking tank truck were removed from the site. Samples taken byPADER and the USEPA Region III Field Investigation Team (FIT) have identified

1-1302056

•*%

1-2

SPRING RUN .

.APPROX. PROPERTY LINE x-̂ _..

EMPTY DRUMS

RESIDENTIAL TRAILER

———————————— KINGS HIGHWAY ROUTE 340

LEGEND2-$- ONSITE MONITORING WELL a IDENTIFICATION NUMBER

•"—- SEEP

S-fĴ DEPRESSION

Z EMBANKMENTroe

302058FIGURE 1-2

SITE LAYOUTBLOSENSKI LANDFILL SiTE. WEST CALM TWR. PA NUS

CORPORATION-3 JT» A Halliburton Company

NOT TO SCALE ———' CORPORATION

DRAFT

soil, surface water, and groundwater contamination with both organic and inorganicsubstances. These findings were verified by the results of the more recentremedial investigation (Rl) performed at the site for the USEPA. The findings arediscussed further in the fallowing section.

1.2 Remedial Investigation Results

The Rl was performed from the Fall of 1984 through the Spring of 1985 to assessthe present and potential impacts of site-related contamination on the publichealth and the environment, and to provide a technical basis for developingappropriate alternative remedial actions for the site. Results of the investigationof various onsite and off site media indicate that the wastes disposed at theBlosenski Landfill Site are the apparent source of contamination found in the

• environmental media of the surrounding area.

1.2.1 Contaminants

Both organic and inorganic chemical constituents were found at the BlosenskiLandfill Site. However, the data indicate that the primary contaminant problem iscaused by volatile organic compounds in the groundwater and other media.Because volatile organics are relatively mobile in the hydrologic cycle, they areconsidered to be indicative of the subsurface migration mechanisms at the landfill.

Volatile organics, and their respective maximum concentrations, detected inmonitoring well and residential well samples taken during the Rl are as follows:

____Chemical____ Maximum Groundwater Concentration (ug/l)

benzene 11,000toluene 600ethylbenzene 54total xylenes 78chlorobenzene 341,1,1-trichloroethane 430

1-4 302059

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____Chemical____ Maximum Groundwater Concentration (ug/l)

1,2-dichloroethane 741,1-dichloroethane 270chloroethane 93tetrachloroethene 5trichloroeihene ' 2601,2-dichloroethene 8901,1-dichioroethene 21vinyl chloride • 450chloroform 270methylene chloride 2,000acetone 43,0002-butanone 3502-hexanone 214-methyl-2-pentanone 7

Data from residential wells surrounding the site indicates that volatile organiccontaminants (primarily trichloroethene and 1,1,1-trichloroethane) have migratedoff site via the groundwater.

Volatile organics were detected in surface and subsurface soils on the eastern,western, and central portions of the site near monitoring wells MW 2-1 andMW 3-1. Sampling did not identify site-related impacts resulting from volatilecontaminants on the intermittent stream north of the site, perhaps due to dryweather conditions prevalent during the Rl.

As compared to the levels of volatile organics contamination detected,environmental media at the site have relatively less contamination by semi-volatiles (acid and base/neutrals), pesticides, polychlorinated biphenyls (PCBs), andinorganic substances. The chemical and analytical results of the Rl indicated thatthese substances appear to be confined to the immediate vicinity of theirdeposition areas (see Rl Report, Section 6.6). Contaminants found in samples takenduring the Rl are summarized in Table 1-1.

1-5 302060

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DRAFT

I 1.2.2 Pathways and Receptors

I The Rl identified the following five pathways for the transport of contaminants topotential receptors.

i• Groundwater Movement - Transport of contaminated groundwater may

J occur via the generally northward hydraulic gradient or through fractures' and joints in underlying bedrock. A perched groundwater zone in the! southeast corner of the site may also play a role in groundwater

contaminant migration.

i • Leachate Production - Precipitation and infiltration may leachcontaminants from waste pockets and contaminated soils into the

f groundwater and overburden material.

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• Erosion and Runoff - Stormwater may cause erosion of contaminatedsurface soils resulting in the contamination of surface waters and

, sediments.I

• Volatilization - Volatile organics could be introduced to ambient air by| soil disturbances or favorable meteorological conditions.

I • Particulate Transport - Respirable dust particles carrying insolublecontaminants may become airborne.

Potential receptors of contaminants at the Blosenski Landfill Site include thefollowing:

• Local residents downgradient (whether by natural or pumping induced; , gradient conditions) of the site who use groundwater for drinking,

showering, lawn watering, and other domestic uses.

1-15 302070

DRAFT

• Onsite remediation workers who may come into contact withcontaminated soil, water, or air during cleanup activities.

• Casual intruders who traverse the site and its environs, and thereby ma\come into contact with contaminated surface soils, surface waters, andsediments. They also may be exposed to windblown, respirable dustcontaining insoluble contaminants.

• Environmental receptors, including onsite terrestrial flora and fauna,aquatic biota in affected surface waters, and terrestrial fauna that useaquatic animals as a food source.

1.2.3 Public Health and Environmental Risks

By assimilating the information on contaminant effects, pathways, and receptors,the Rl identified risks to the public health and the environment resulting from theBlosenski Landfill Site. Potential public health risks associated with the variouscontaminated media are summarized below.

• Groundwater - The major exposure path and subsequent potential publichealth risk at the site is through the ingestion and domestic use ofcontaminated groundwater. Although the two organics-contaminatedresidential wells are located upgradient of the site, fractured bedrock andwell pumping may have drawn the mobile (volatile) compounds from thesite. Contaminant concentrations found in these residential andmonitoring well samples exceed health criteria such as USEPA HealthAdvisories (SNARLS) for 10-day acute effects and subchronic toxiceffects, and for long-term chronic health impacts due to contaminantingestion, as well as Safe Drinking Water Act Maximum ContaminantLevels (MCLs).

1-16

302071

I

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DRAFT

At the concentrations in the more contaminated residential well, thepotential risk of exposures from volatilization of contaminants duringshower usage exceeds the potential exposure from ingestion. Theabsorption of contaminants during bathing may be comparable to thatfrom direct groundwater ingestion. At the contaminant concentrationsfound during the Rl, ingestion of the groundwater carries a correspondingcancer risk in excess of 10 , based on the* EPA's Unit Cancer RiskPreliminary Protective Concentration Limits (PPCLS). These risk levelsare summarized in Table 1-2. At the mean concentrations for thecarcinogens identified in the Rl, the estimated corresponding totalpotential risk level, due to ingestion of water from the two contaminated

-2 -2residential wells is 2.6 x 10 , and is 1.8 x 10 for ingestion of waterfrom contaminated monitoring wells. Since the residents with thecontaminated wells are drinking bottled water, these risk levels areconservative.

• Surface Waters and Sediments - Surface waters and sediments have beenrelatively unaffected by organic contaminants from the site, and acuteeffects from ingestion, inhalation, or dermal exposure do not appear to bea major problem. However, levels of chloroform and nickel in surfacewaters exceeded the chronic health effects Ambient Water QualityCriteria (AWQC) for long-term ingestion. However, the surface watersare not known to be used as drinking water in the site vicinity. TheAWQC for the protection of human health via ingestion of aquaticorganisms were not exceeded for any identified contaminants.

• Surface and Subsurface Soils - There has been no identified route ofexposure to contaminants in the subsurface soils. Mobile, volatilecontaminants were found at relatively low concentrations in the soils.Therefore, they should not significantly affect the groundwater.Phthalate esters, pesticides, and PCBs were found at somewhat higherconcentrations. However, they are less mobile than the volatiles and tendto adhere to soil particles, thus presenting a lesser threat to groundwater.

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Acute exposure, however, to subsurface contaminants could occur duringa major soil disturbance.

The potential for exposure to surface soils is much greater than tosubsurface soils through direct contact/dermal adsorption, dust inhalation,and accidental ingestion. Although acute effects are highly unlikely,except during soil disturbance, chronic effects* may occur through directcontact with PCBs, phthalate esters, and polynuclear aromatics, orthrough inhalation of released volatiles.

• Source Areas - In the event of a major disturbance to identified sourceareas or buried drums, the potential for dermal exposures increasessignificantly.

• Air - Based on a qualitative measurement of volatilized contaminantswithin monitoring well MW 2-1, atmospheric concentrations ofcontaminants at the site would not be expected to exceed the City ofPhiladelphia's recommended guidelines for average yearly concentrations.Thus, health impacts would not be expected via inhalation. However, soildisturbance during site remediation may result in volatilization and theintroduction of contaminated airborne dust particles. Monitoring andproper construction techniques will reduce these potential health impacts.

Environmental risks from the Blosenski Landfill Site include the following:

• Surface Waters and Sediments - Levels of contaminants found in surfacewaters and sediments are low. The Ri data did not indicate any acute orchronic risks to aquatic biota.

* Soils jnd Groundwater - The Rl data indicate that onsite soils andgroundwater present a low, chronic risk to biota at this time.

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IDRAFT

1.3 Remedial Action Objectives and Criteria

The overall purpose of the Feasibility Study (FS) process is to provide an array oftechnically sound, cost-effective remedial action alternatives that control thesource and manage the migration of contaminants, and to provide protection topublic health, welfare, and the environment. To meet this overall purpose, specificcleanup objectives and criteria are necessary to provide a focus for the generalresponse actions and technologies available for remediating the Blosenski LandfillSite.

Each of the contaminant pathways and potential receptors identified in the Rl anddiscussed in the previous sections were evaluated under the following objectivesand criteria:

Cleanup Objectives Cleanup Criteria

a. No action a. Establish current potential risklevels and take no remedial action

b. Prevent an increase in the current b. Establish current potential riskpotential risk associated with the levels and utilize remedial tech-site nologies to prevent increase in

potential risk levels

c. Reduce the current potential risk c. Reduce the current potential riskassociated with the site to an associated with the site to aacceptable level target cleanup criteria of a

10~6 potential risk level, orother acceptable level.

d. Reduction of risk levels to those d. Utilize remedial technologiescorresponding to background concen- to eliminate site contaminantstrations

The results of that evaluation process are discussed in the following paragraphs.

3020761-21

DRAFT

1.3.1 Contaminated Groundwater

The most significant potential public health risk associated with the site is toreceptors who ingest, shower with, or use the contaminated groundwater in waysthat promote direct dermal contact and/or inhalation of volatilized contaminants.Site contaminants have been found in domestic wells south of the site. Theprimary pathway for contaminant migration is through the highly fractured bedrockgroundwater system that underlies the site. Volatile organic contaminants thatenter the system move in fractures and along relict bedding joints with little or noattenuation or adsorption of the contaminants. The complex fracture systemprecludes accurate prediction of the specific flow path and flow rate of thecontaminant plume. However, the regional groundwater system flows toward thenorth, and site contaminants may be discharged into an unnamed intermittenttributary of Indian Spring Run, north of the site. Indian Spring Run is classified byPADER as a protected stream for the prooagation of cold water fish species. Ifsite contaminants enter the stream, they could adversely affect stream biota.

The cleanup objectives of no-action and preventing further increase of risk are notappropriate to the groundwater contamination problem because of the highpotential health risks associated with ingestion, inhalation, or contact with thegroundwater contaminants. The objectives of reducing current potential risks toacceptable or background levels are acceptable and feasible, since correspondingcontaminant levels associated with the site c*»n be reduced by availabletechnologies.

As defined by the National Contingency Plan (NCP, 40 CFR 300), and EPA'sGuidance on Feasibility Studies Under CERCLA (USEPA, June 1985), an acceptabletarget cleanup criterion for the reduction of risk is a level of 10~4 to 10"?. Thetarget cleanup criterion used in this FS for reducing the public health risk to anacceptable level is the reduction of the volatile organic contaminants to theirrespective 10~6 risk levels. For the volatile organic contaminants found at thissite, the 10~6 risk levels are the maximum contaminant levels (MCLs) as shown inTable 1-3.

1-22 302077

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DRAFT

TABLE 1-3

PROPOSED GROUNDWATER TREATMENT STANDARDSBLOSENSKI LANDFILL SITE

RecommendedMaximum Contaminant 4 Maximum Contaminant

Level (RMCL)O) Level (MCL)

DRAFT

The target clean-up criteria for the elimination of site contaminants is backgroundconcentrations of site contaminants in the groundwater system. In most cases thisbackground level for volatile organics is zero. However, this level may notnecessarily be analytically confirmable.

1.3.2 Contaminated Surface Soils and Sedimentsi

The most significant potential pu:.:ic health risk associated with this pathway is tochildren, who may accidentally ingest contaminated soils if playing on the site, andto other casual intruders, who may come in dermal contact with the contaminatedsoils. The Rl reported that there is no significant health risk associated with thelevel of surface contaminants found on site and in nearby sediments. However,there is potential for increased risk if the site erosion is allowed to continue.

The no-action and the prevent-increase-in-risk objectives are not appropriate tothe contaminated soil pathway because of the future public health risk associatedwith migration of the soil contaminants. The reduction-of-risk objectives arefeasible because the contamination levels can be reduced by available technologies.

An acceptable target cleanup criterion for reducing the potential health riskassociated with the contaminated soil exposure pathways is a corresponding risklevel of 10~6. jo attain a 10~6 rjsk, the following soil contaminants must bereduced to their respective concentration levels, shown below:

Dermal Contact (Casual Intruders)

3,3' Dichlorobenzidine 3 mg/kgPolynuclear aromatics (Total) 0.5 mg/kgPCB's (Total) 1 mg/kg

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DRAFT

Soil Ingestion (Children)

3,3' Dichlorobenzidine 8 mg/kgPolynuclear aromatics (Total) 1 mg/kgPCB's (Total) 3 mg/kg

The elimination of site contaminants will require the reduction of all contaminantsto concentration levels equal to or less than background levels. In most cases, thislevel is considered to be zero, and may not be analytically confirmable.

1.3.3 Respirable Contaminants

This pathway includes dust particles that contain sorbed contaminants, particles ofnonvolatile contaminants, and volatilized site contaminants. The only appropriateobjective in this category is to maintain the current risk levels during any futuresite remediation or atmospheric condition. Reduction and/or elimination of thepotential health risk levels can be attained by meeting the objectives and targetcleanup criteria of the other contaminant pathways. Therefore, they are notproposed as feasible objectives for remediation of this pathway. Standard acceptedengineering practices and construction management techniques will properlyaddress risk concerns during remediation activities.

Table 1-4 lists the general response actions that m^et the cleanup objectives andcriteria for the contaminant exposure pathways. In Section 2.0 of this report,these actions will be broken down into site-specific remedial technologies andscreened for remediation applicability on the basis of technical feasibility, publichealth and environmental impacts, institutional issues, and costs.

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1.4 Feasibility Study Procedure

The FS process is intended to develop and evaluate remedial action alternatives forthe site using data obtained during the R! and using other site-related informationobtained from local, state, and Federal agencies. As a minimum, one alternativewill be developed for each of the five cleanup categories described in the USEPAGuidance Document on Feasibility Studies Under CERCLA (USEPA, June 1985).These categories are described further in Section 3.0 and include the no-actionalternative as a baseline alternative.

The methodology for preparation of this FS parallels the procedure outlined in theGuidance Document and the NCP. This procedure is as follows.

• Identify General Response Actions - General Response Actions (GRAs)were identified which address the site problems and contaminantpathways identified during the Rl. Corresponding objectives and criteriato be used in evaluating technologies within each GRA were developed foreach contaminant pathway.

• Identify and Screen Technologies - Technologies were identified for eachGRA and screened against the site-specific cleanup objectives andcriteria. Technologies not meeting the site cleanup objectives andcriteria were eliminated from further consideration, whereas thoseremaining were screened by additional crteria. These additionalscreening criteria included technical feasibility; ability to adequatelyprotect the public health, welfare, • and the environment; costconsiderations; and institutional constraints. The results of thetechnology screening are presented in Section 2.0 of this report.

• De.elop Remedial Action Alternatives - Remedial Action Alternatives(RAAs) were developed from the remaining technologies in each GRAcategory. Alternatives judged to have significant adverse impacts or thatwere judged to be significantly higher in cost without providing

1-28 302083

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I

I

1f

DRAFT

significantly greater benefits were excluded from consideration. At leastone RAA was provided for each of the five USEPA cleanup categories, asrecommended in the Guidance Document. These RAAs are discussed inSection 3.0 of this report.

The resulting group of alternatives were evaluated according to the samecriteria used to screen the technologies: technical feasibility, health andenvironmental impacts, costs, and institutional concerns. The results ofthe detailed evaluation process are discussed in Section 4.0 of this report.The RAAs evaluated in Section 4.0 are summarized in Section 5.0 tofacilitate EPA's review and selection of the appropriate remedial actionfor the Blosenski Landfill Site.

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DRAFT

2.0 SCREENING OF REMEDIAL ACTION TECHNOLOGIES

2.1 Screening Criteria

This section describes the screening process used to identify the most appropriateor effective technologies for mitigating contamination problems at the BlosenskiLandfill Site. A list of candidate technologies will be identified and evaluated toeliminate technologies that do not satisfy the appropriate cleanup objectives andmeet technical and environmental criteria. This section summarizes the majorjustifications for retaining or eliminating the remedial technologies. Detailedbackground screening data are provided in Appendix A. The screening criteriaconsist of:

• Satisfaction of site-specific objectives• Technical feasibility• Health and environmental impacts• Cost of implementation• Institutional considerations

Technologies that pass the screening process will be retained for development intoappropriate RAAs.

2.1.1 Satisfaction of Remedial Action Objectives

Only technologies that satisfy the appropriate remedial action objectives will befurther screened by the remaining criteria. Those-objectives listed in Section 1.3will be the basis for choosing applicable remedial technologies. A technology maybe technically feasible and cost attractive, but if it does not satisfy theappropriate cleanup objectives, it is considered inappropriate for the site.

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DRAFT

2.1.2 Technical Feasibility

Technologies will be evaluated in terms of their ability to provide the desiredremediation, such as containment, treatment, or disposal. Each technology will beevaluated based on the following technical criteria:

t,

• Performance• Implementability• Reliability• Safety

The performance of each technology will be evaluated in terms of its effectivenessin satisfying the cleanup objectives through applicable technical standards andcriteria. Technologies should also provide remediation for an extended time,.usually 30 years, without significant deterioration. The technologies should beimplementable; that is, they should be constructabie under the site conditions andin a timely manner. It is important for the technologies to be reliable, asdetermined by previous performance data under similar conditions, ideally, thetechnologies should have infrequent operation and maintenance (O&M)requirements, which should be as simplified as possible when required. Eachtechnology should also be implementable with minimum health effects, both toremedial workers and to the surrounding community. Consideration will be givento innovative technologies as they may be applicable to site conditions.

2.1.3 Health and Environmental Impacts

Each technology will be evaluated for its impact on both public health and theenvironment. Both beneficial and adverse impacts will be assessed for thetechnologies that address the site-specific problems and contamination pathways.The impacts associated with both implementation and post-closure activities willbe considered.

2-2 302087

DRAFT

2.1.4 Cost Evaluation

Costs will be determined, as required, to screen out technologies for which resultsof the other screening criteria are essentially the same. Cost estimates willinclude capital costs and O&M costs, which will be used to screen out technologiesthat provide similar degrees of remediation but cost significantly (e.g., an order ofmagnitude) more.

2.1.5 Institutional Considerations

The applicable Federal, state, and local standards, regulations, and ordinances willbe addressed for each technology. Any indirect community or other impacts willalso be discussed in this section, as applicable.

22 Candidate General Response Actions and Technologies

The possible technologies used to remediate a site can be classified into groupscalled General Response Actions (GRAs), each of which can be used to control acontaminated media or its migration pathway. Table 2-1 contains a comprehensivelisting of GRAs and technologies that can be used for a hazardous waste siteremediation. This list is provided to help ensure the consideration of all possibletechnologies.

2.3 Technology Screening Process

Table 2-1 of this report identifies various GRAs that may be applicable forcontaminant source and migration control at the Blosenski Landfill Site. Thissection describes the screening process used to identify, within GRA categories,the appropriate or effective technologies for mitigating contamination under site-specific conditions. The technologies are examined based on their ability to meetthe cleanup objectives listed in Section 1.3, their technical feasibility, health andenvironmental impacts, costs of implementation, and institutional criteria.

f302088

DRAFT

TABLE 2-1

GENERAL RESPONSE ACTIONS AND ASSOCIATEDREMEDIAL TECHNOLOGIES

General Response___Actions___ __________Remedial Technologies__________

X

No Action - Some monitoring and analyse may be included

Containment - Capping; dust control; addition of freeboard; groundwatercontainment barrier walls; bulkheads; gas barriers

Pumping - Groundwater pumping; liquid removal; dredging

Collection - Sedimentation basins; French drains; gas vents; gascollection systems

Diversion - Grading; dikes and berms; stream diversion ditches,trenches, and diversions; terraces and benches; chutes anddownpipes; levees; seepage basins

Complete Removal - Tanks; drums; soils; sediments; liquid wastes,contaminated structures; sewers and water pipes

Partial Removal - Tanks; drums; soils; sediments; liquid wastes

Onsite Treatment - Incineration; solidification; biological, chemical, andphysical treatment

Offsite Treatment - Incineration; biological, chemical, and physical treatment(POTW or pretreatment facility)

In-situ Treatment - Permeable treatment beds; bioreclamation; soil flushing;neutralization; land farming

Storage - Temporary storage structures

Onsite Disposal - Landfills; deep well injection

Offsite Disposal - Landfills; surface impoundments; land application

Alternative Water - Bottled water; cisterns; above-ground tanks; deeper orSupply upgradient wells; municipal water system; relocation of

intake structure; individual treatment devices

Relocation - Relocate residents, businesses, and habitat areas

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DRAFT

Technologies that obviously are not appropriate for meeting the cleanup objectives,and technologies found not to be effective under site-specific conditions will not beevaluated further. Those passing the initial screening will be retained fordevelopment into appropriate remedial action alternatives.

2.3.1 No Action with Monitoring

Although not a remedial action technology per se, an evaluation of the no actionalternative provides a baseline evaluation of current site conditions, against whichthe relative effectiveness of other remedial actions may be compared. The currentextent of contamination was determined by sampling and analysis conducted duringthe Rl.

The no action alternative will not reduce any exposure risks or potential impacts topublic health and the environment. The addition of continued monitoring, however,will provide a mechanism to determine the trends of future contaminantconcentrations and migration from the site. Samples should be taken periodically(every 3 to 12 months) and should include surface soil and groundwater samples.All samples should be analyzed for EPA Hazardous Substance List (HSL)compounds, including volatile organics, inorganics, pesticides, and PCBs.

2.3.2 Containment

2.3.2.1 Surface Capping

Two of the mechanisms that are contributing to contaminant migration from theBlosenski Landfill Site are leachate generation due to infiltration of rainfall, anderosion of contaminated soils or wastes caused by storm water runoff. These twomechanisms can be controlled by installing a protective cap that reduces the rateof infiltration and protects the contaminated media from the erosional effects ofstorm water. Surface capping is a technology that has been effectively utilized inindustry and in the management of uncontrolled hazardous waste sites to controlthe contaminant migration mechanisms of infiltration and storm water runoff.

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DRAFT

Potential surface capping materials include synthetic membranes, low permeabiitysoils (clays, silty clays, clayey silts, and selected silts), local soil materials, asphaltmaterials, chemical stabilizers, or a multimedia cap constructed of lowpermeability soils and synthetic membrane layers. The following paragraphsdiscuss the application, of the above capping materials and their relativeapplicabiity to the Blosenski Landfill Site.

• Synthetic Membranes

Synthetic membranes are considered state-of-the-art for obtainingminimal infiltration rates as both liners and caps. A wide variety ofpc'ymeric and synthetic materials are available for use as liners and caps.Some of the more common types of synthetic membrane materials arehigh density polyethylene (HOPE), polyvinyl chloride (PVC), chlorinatedpolyethylene (CPE), chlorosulfonated polyethylene (CSPE), butyl rubber,anc1 ethylene propylene rubber.

The thickness of the synthetic membrane is determined in thousandths ofan inch, or mils. Membranes range in thickness from 10 mils to over100 mils. A January 1985 information package from the EPA HazardousSite Control Division recommended that a synthetic membrane used inconjunction with 2 feet of compacted, low permeability soils to form acap meeting RCRA specifications be at least 20 mils thick, and that 60 to100 mils is frequently used by industry. The May 1985 MinimumTechnology Guidance on Double Liner Systems for Landfills and SurfaceImpoundments—Design, Construction, and" Operation recommends that a30-mil membrane be utilized for liners that are protected by a blanket ofsoil from the effects of sun and weathering, and that a 45-mil membranebe utilized if the membrane was exposed or uncovered for a year or more.

The selection of both the type of synthetic material and the thickness of asynthetic membrane will depend on the site-specific application of themembrane and the ability of the synthetic membrane to meet the

2-6

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DRAFT

1 objectives established for a remedial action alternative. The BlosenskiLandfill Site has several characteristics that limit the effectiveness and

I reliability of a synthetic membrane cap alone. The site has beenidentified as a municipal solid waste (MSW) landfill along with theindustrial waste and solvent disposal activities that the RI/FS has focused

/ on. MSW is subjected to an anaerobic decomposition and degradationprocess when placed in a landfill. The process can cause settling and

^ consolidation of the deposited MSW by as much as 30 to 50 percent overthe life of the landfill. Synthetic membranes and the welds or seams that

| hold the panels of membrane together to form a cap are susceptible tofailure when waste pockets settle. The synthetic membrane is stretched

1 and elongated which reduces its ability to resist infiltration and if enough* settling occurs, the membrane in that area could fail completely. ThereI • is also some concern that the site contaminants and their interaction withI each other might degrade the synthetic material over time. The

installation of the synthetic membrane and subsequent constructionactivities associated with completing or maintaining a remedial actionexposes the membrane to equipment operations that could cause damage.Burrowing animals could also damage the synthetic membrane. Thesynthetic membrane also creates a low friction surface that makes itdifficult to place cover materiais or granular collection materials overthe membrane in steep sloped areas. There have been incidences wherematerials have slid off a synthetic membrane after a rain storm. The rainwaters infiltrated the cover materials, formed a phreatic zone along theinterface, and created a failure plane.

A synthetic membrane cap for the Blosenski Landfill is not a goodtechnology by itself. There are implementability, reliability, anddurability problems that could cause failure or reduced performance of asynthetic membrane cap. The cap would not control the rate ofinfiltration and, without a protective zone of soil and vegetative cover,the storm water runoff from about 9.5 acres of impervious area would bedifficult to control. The use of a synthetic membrane in conjunction with

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DRAFT

low permeability soils is a better technology that offers a backupimpervious zone in case of membrane deterioration or failure. Theadditional cost of a multimedia cap is not an order of magnitude higherthan a synthetic cap alone, and will be retained for further evaluation.

Low Permeability Soils*

Low permeability soils are considered to be soils that, when compacted,exhibit a permeability less than or equal to 1.0 x 10~7 cm/sec. Typically,these soils fall within the Unified Soils Classification System (USCS)classifications of clays, silty clays, clayey silts, and silts depending ontheir plasticity index and organic or inorganic determination. Lowpermeability soil caps, often called clay caps, are constructed of thicklayers of compacted fine-grained soils. The soil is placed in loose lifts ,

I

6 to 12 inches thick and then machine compacted to a predetermined 'density. This process is repeated until a compacted layer of soil severalfeet thick is attained. The thickness of the cap is generally in the range Iof 2 to 3 feet. The amount of compaction required to attain apermeability within the range of 10"̂ cm/sec is typically in excess of •

:90 percent of the soils maximum dry density as determined by standard ormodified compaction tests.

It is extremely important to note that density and permeabilities that areattained in the laboratory are not likely to be duplicated in the field. Thelaboratory is a controlled environment and the purpose of the laboratorytests are to develop a standard for field construction activities. Thelaboratory test procedure for compaction testing utilizes impact energyto compact the laboratory soil samples, while most field compactionmethods use kneading and/or static pressure. Standard practice forlaboratory permeability testing utilizes the remolded soil sample that wassubjected to the impact compaction method. It is not unrealistic to findthat a properly constructed, low permeability soil cap will exhibit a

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permeability that is an order of magnitude greater than the laboratorypermeability test results.

The selection of a suitable low permeability soil for use as an imperviouscap will require extensive testing and evaluation. The soils in the areawill have to be sampled and tested for grain size distribution, plasticity,permeability, compatibility with the chemical characteristics of theinfiltration expected to occur at the site, and compactibility. However,the Blosenski Landfill site has one physical characteristic that is notcompatible with the use of a compacted, low permeability soil cap as thesingular means of reducing the amount of infiltration generated lechate.The MSW deposited at the site is not a suitable base for the constructionof a compacted, controlled fill. The MSW exhibits an elastic rebound thatwill continually subject the placed, compacted material to a wave-likemotion. The result is an inability to achieve the degree of compactionnecessary to attain a 1.0 x 10~7 cm/sec permeability and numeroussurface fractures in the plastic action of the soils.

A low permeability soil cap for the Blosenski Landfill Site is not a goodtechnology by itself. The compaction forces needed to attain a1.0 x 10~7 cm/sec permeability in a fine-grained soil cannot be achieveddue to the elastic properties exhibited by MSW landfills. The elasticrebound will also cause surface tension cracks due to plasticity of thefine-grained soils. Soils with larger particles and less plasticity can beused to overcome the problems, but they will generally exhibitpermeabilities within the range of 10~5 cm/sec. A soil cap with thoseproperties is screened later in this section. The low permeability soilsdiscussed above are also used in a later part of this section as part of amultimedia cap technology screening and, therefore, will be retained forfurther evaluation.

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Soil Cap

Soil caps are considered to be a thick layer of compacted, local soils thatcan be effective in reducing the amount of infiltration related leachate,but are primarily used to create a barrier between the site contaminantsand receptors that might otherwise ingest or contact the surfacecontaminants. They are also used in controlling erosion relatedcontaminant migration. Based on the soil information presented in the Rl,the soils found near the Blosenski Landfill Site are generally of theEdgemont Series and consist of loams, silty loams, and silts. Thesetextures of materials typically exhibit permeabilities within the range of10~5 cm/sec.

In order to aid in evaluating the effectiveness of a soil cap constructedfrom local soils, the HELP computer model was run on all the potentialcap materials discussed in this section and on the existing site conditions.Since regional climatological data and default soil data was used in theHELP simulations, the results of the computer simulations are presentedas a relative percentage decrease in leachate production based on existingconditions. For example, the HELP model showed a 2-foot-thick soil capwith a permeability of 10~5 cm/sec to produce 99 percent less leachatethan the existing site conditions.

The use of a 2-foot-thick soil cap with a permeability of 10~5 cm/sec isan effective technology to reduce leachate production and controlcontaminant migration caused by erosion. The compaction problemsidentified with the low permeability soil cap presented earlier will notadversely impact the silty, loamy soils used in this soil cap. The largersized soil particles will not require the same amount of compaction forceto attain maximum densities, and the plasticity of this texture of materialshould not create extensive or uncontrolled surface tension cracks. Thedesired permeability should be attainable in these types of fieldconditions. The additional cost of securing clay-like soils and compacting

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them to a lower density to attain similar permeability does not appear tobe a feasible option for the soil cap technology. Local borrow should beless expensive to buy and to transport to the site if a nearby supplier canbe found.

Although this technology does reduce the amount of leachate produced bythe site, it does not effectively control the source in a manner that allowsit to be considered a source control remedy. This technology should notbe combined with other technologies that call for contaminant migrationremediation unless another source control technology is also incorporatedinto the remedial action alternative.

Multimedia Cap

Multimedia caps are a combination of low permeability soils and syntheticmembranes in conjunction with an overlying layer of protective soil thatcan also support vegetation. In most cases, an infiltration collection andflow zone is added between the synthetic membrane and the protectivesoil cover. The combined effect of the low permeability soils and thesynthetic membrane is not an overall decrease in the permeability of thecap, but rather a factor of safety in case one or the other imperviousmedia fail or deteriorate.

The Blosenski Landfill Site is not suitable for capping with either thesynthetic membrane or the low permeability soils alone. However, thesite can be capped with a multimedia system which will compensate forthe weaknesses of the individual materials. The soils will not attain a10~7 cm/sec permeability, but the synthetic membrane will. Thesynthetic membrane can be damaged through waste settlement orconstruction activities, but the soils will have a tendency to mold and flexwith the settlement and construction activities. There is also someevidence that the weight of the multimedia cap and the moistureretention capabilities of the synthetic membrane will create a

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consolidation effect on the soils, while keeping the soils at or aboveoptimum moisture. This combined effect may decrease the relativepermeability of the compacted soils and create a more uniforminfiltration barrier.

The capital costs for a multimedia cap versus a synthetic membrane capor a low permeability soil cap is not at. order of magnitude higher.Preliminary cost estimates for the multimeu.d cap is about $3,000,000 andthe cost for a low permeability cap is about $1,000,000 for a 9.5-acresite. The cost estimate for a synthetic membrane cap is expected to fallbetween these estimates. A multimedia cap for the Blosenski LandfillSite is a feasible technology that can be combined with other technologiesto remediate the site. This technology can also be used as a sourcecontrol remedy since it effectively reduces leachate production to nearzero.

• Asphalt Cap

Asphalt caps may be constructed over a prepared subgrade tosubstantially reduce infiltration. However, asphalt liners are subject tocracking from subgrade failure. This is especially true for an areacontaining refuse, which is subject to subsidence from wastedecomposition. Because of their structural instability, asphalt liners willnot be retained for further evaluation.

• Chemically Stabilized Caps

Chemical stabilization involves excavating the present cover materials,mixing them with lime or bentonite, and replacing them, thereby forminga more impermeable cover material. These cemented soils are subject tocracking from freeze-thaw stresses and may deteriorate upon extendedexposure to organic solvents vapors. Due to their long-term instability,

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chemically stabilized surface caps will not be retained for furtherevaluation.

2.3.2.2 Groundwater Barriers

One of the site objectives is to reduce the potential public health risks associated*

with consuming groundwater contaminants. A groundwater barrier can help toachieve this goal by containing the groundwater within the site and isolating itfrom the off site receptors. Groundwater barriers can also be used to blockgroundwater movement so that it can be collected more easily. Highly fracturedbedrock formations, however, reduce the effectiveness of groundwater barriers.

• Soil-Bentonite Slurry Wall

A soil-bentonite slurry wall involves excavating a trench down to bedrockunder a slurry of bentonite clay and water, then backfilling the trenchwith the original soil admixed with the slurry to form a low permeabilityboundary. The water table at the Blosenski Landfill is at or below thebedrock surface. Since slurry walls only extend down to bedrock, theywould not be effective in reducing groundwater movement.

• Grout Curtains

A grout curtain is a seal formed in soil or rock voids from suspensionfluids that have been pressure injected and allowed to set up. It can beused to either contain groundwater or control its flow direction.However, containing groundwater in fractured bedrock would be difficult,due to the complex fracture network. The ability to check for a sealafter grout installation is questionable. Also, the long-term effectivenessof a grout curtain exposed to dilute contaminant concentrations isquestionable. Since the residential wells adjacent to the site are up to150 feet deep, the grout curtain should extend to that same depth.Because of the depth of seal required, a grout curtain would be a very

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expensive technology. Preliminary estimates (Appendix A) indicate a costof $3,000,000 for a 1400 foot wall extending 150 feet into bedrock thatwould be located between the contaminated wastes and the residences.Tor these reasons, a grout curtain will not be evaluated further.

2.3.3 Groundwater Collection4

The groundwater contaminant concentrations beneath the site currently correspondto unacceptable potential health risk levels. One method of reducing the risks toacceptable levels is to collect the contaminated groundwater to reduce itsmigration off site. There are two general methods for collecting groundwater.One method is a passive system using collection drains to intercept thegroundwater, and the other is an active system utilizing pumping to increase theflow and removal rates.

2.3.3.1 Subsurface Collection Drains

Subsurface collection drains work well in excavatable soil. At this site,groundwater is located within the bedrock which, based on Rl data, isapproximately 30 feet below the surface. The deepest residential well is believedto be approximately 150 feet deep. The collection drain would have to be at leastthis deep to reduce contamination passing beneath the drain. This would involveexcavating approximately 120 feet of bedrock. The cost of this technology wouldbe at least an order of magnitude greater than pumping and, therefore, will not beconsidered for further evaluation.

2.3.3.2 Groundwater Pumping

Pumping is the most widely used method of groundwater extraction. Because thegrourriwaxer flow at the site is influenced by fractures, additional aquifer testingshould be performed during the design phase to optimize groundwater removalsystem design.

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Groundwater pumping is feasible for the following reasons: (1) aquifer testingduring the Rl identified sustained yields with groundwater being intercepted in thedeep monitoring wells; and (2) the residences have been able to extractgroundwater on a long-term basis. Even though it is unlikely that all the fracturescontaining contaminants can be intercepted, the overall gradient can be controlledso that groundwater in the fractures between the well points will eventually flowtoward the pumping well. Although groundwater pumping in fractured bedrock\poses difficulties, it remains a proven and cost-effective technology forgroundwater extraction.

Once the groundwater is pumped and treated, it must be discharged to theappropriate medium. The treatment plant effluent will meet drinking waterstandards (MCLs), so there should be little if any risk in contaminating the aquifer.Discharging to the intermittent stream was considered; however, this type ofdischarge would eventually infiltrate to the groundwater. Discharging to a drystream might also cause problems with respect to erosion of contaminatedsediments. For these reasons, injection to the aquifer was chosen as the dischargemethod.

Groundwater injection may be accomplished by using seepage basins or well points.Injection should be by wells because basins in soil have a potential for clogging atthe surface, whereas injection wells bypass the soil and go straight to the bedrockaquifer. Also, clogging of the basins could cause the discharged water to migratelaterally which could flood low-lying areas. Injection wells can be installed at thesame time that the well points are installed for groundwater pumping.

Injection wells should be located upgradient of the site to create a cycle of flowthrough the waste and enhance flushing of the contaminated groundwater. This canbest be done by locating the wells between the site and the residences to the south.The depth of the wells should be approximately 100 feet to attain a sufficientrecharge rate.

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2.3.4 Surface Water Controls

Surface water diversion is an effective method of controlling the erosion ofcontaminated sediments associated with storm water runoff. Althoughcontamination of surface water and sediments does not appear to pose anunacceptable risk, the possibility of future releases should be minimized. Thesereleases can be minimized by utilizing proper erosion and sediment controls.Diversion structures are relatively minor technologies, which are used as ancillarymeasures to other remedial technologies. Structures such as berms, ditches, andsediment traps are relatively inexpensive items used on any type of constructionactivity. Therefore, surface water controls will be retained for further evaluation.

23.5 Contaminant Excavation/Removal

Excavation involves removing contaminated soils and wastes from their presentlocation in preparation for onsite or off site treatment or disposal. Since the sourceof contamination is actually removed, the residual risks associated with exposureto surface water and airborne migration are expected to be reduced toapproximately background levels. Excavation will not reduce the risk associatedwith existing groundwater contamination. It will, however, reduce the futuregeneration of leachate.

Excavation of waste materials may pose health and safety problems to the workersthrough direct contact or through volatilization of organic wastes. These hazardscan be greatly reduced by using proper equipment and construction techniques.Excavation and/or removal will be retained for further evaluation.

2.3.6 Innovative Treatment Technologies

The purpose of this section U to present innovative and emerging technologies,screen them under the criteria and objectives established previously, and developpotential remedial technologies for use with other technologies as remedial actionalternatives. For this report, an innovative technology is defined as a technology

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that has not been established specifically for the particular waste on which it is tobe used However, it has proved successful in remediation of other wastes. Anemerging technology is a technology that is still in the research stage and has notbeen utilized in industry.

The fractured bedrock that underlies the Blosenski Landfill Site has eliminatedmost of the innovative and emerging technologies reviewed for potentialapplication as a remedial technology. Many of the technologies utilize in-situtreatment as part of their detoxification processes and require the controlledinjection and extraction of solvents, microorganisms, nutrients, or chemicals.Therefore, the fractured bedrock cannot be considered a reliable or predictablemedia. A more complete list of the innovative technologies that were evaluated isincluded in Appendix A of this report.

One innovative technology that might be applicable is in-situ vitrification. Thisin-situ detoxification process utilizes electricity to create extremely hightemperatures in the waste or soil. The high temperatures (2,000°F to 3,600°F)actually melt the soils or wastes, forming a pool of liquified material that coolsand creates a glassified media. The theory behind the technology is that mostcontaminants are destroyed in the liquification process, the volatile materials aredestroyed as they try to escape upward and encounter the 3,600°C liquified soil,and the remaining metals are stabilized within the glassified residual. Althoughthis is a fascinating technology, it is not a technology that can be applied or testedat the site. The mass liquification of soils and wastes is too risky and there are toomany unknowns. The potential risks are extremely high during the treatmentprocess and the public perception of melting soils and wastes as a remedy for thesite cannot be expected to be favorable.

Several other innovative technologies were reviewed and evaluated that did notutilize in-situ treatment processes. Typically, these technologies required theexcavation of the media to be detoxified and the placement of the excavatedmaterials into a treatment process. Discussion of the technologies that wereevaluated under this scenario is included in Appendix A of this report.

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The one technology that was thought to be feasible for additional study was a soilwashing technolgoy. Although this technology was not suitable for use on thecontaminated wastes, the use of a soil washing technology on the contaminatedsoils that underlie the wastes was selected for further study. This does not meanto imply that soils washing is a feasible technology for remediating thecontaminated soils at the Blosenski Landfill Site. Rather, it is a promisingtechnology for which additional testing and evaluation appears to be warranted atthis time. An initial study and a pilot study is recommended as part of a remedialaction alternative that utilizes another form of source control remedy, thusproviding EPA the option to remediate the contaminated soils with a proventechnology should the additional studies find that soil washing is not applicable tothis site.

2.3.7 Groundwater Treatment

Groundwater treatment can be used prior to discharge of extracted and collectedgroundwater to reduce the contaminant levels. This would ensure the protection ofthe environment by reducing the impact of groundwater contaminants on receptorswhile restoring the natural groundwater resource. This technology would be used inconjunction with groundwater extraction and injection discussed previously.

In the long-term, the restoration of the groundwater quality to the NCP'sacceptable risk levels of 10~4 to 10~7 or to background levels will provide a futurepotable water source for nearby residents. Because the groundwater adjacent tothe landfill is used directly as a water supply via residential wells, the applicablestandards are the maximum contaminant levels (MCLs) as promulgated under theSafe Drinking Water Act, or alternate contaminant levels (ACLs) determined bythe regulatory agencies on a site-specific basis. The contaminants in thegroundwater that exceed these standards are predominantly the volatile organics.

There are several types of proven technologies that can be used to remove volatileorganics from water. Therefore, technical infeasibility will not eliminate thetechnologies from consideration. Any type of treatment process will require

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meeting discharge permit requirements as specified under the Federal CleanStream Law (PL 1987, No. 394). The following unit processes are applicable in

I removing volatile organics to provide the desired degree of treatment.

2.3.7.1 Carbon AdsorptionI

Adsorption by activated carbon is suitable for removing a wide variety of> contaminants including volatile organics, most acid extractables, and pesticides.

These types of contaminants have been reduced to at least 10 ug/l in industrialj applications. The environmental impacts of carbon adsorption are minimal, since

the absorbed contaminants are contained within the spent contact chambers, whichI can be disposed of easily or regenerated. Carbon adsorption is generally more

costly than other treatment processes. However, the resulting effluent is higher inquality. Carbon adsorption will be retained for further evaluation.

2.3.7.2 Biological Treatment

Groundwater at the Blosenski Landfill Site contains organic contaminants that maybe biodegradable through biological treatment. Except for a few isolated samples,however, the concentration of organic compounds found in the groundwater isbelow the effluent concentration achievable by conventional biological processes.Also, most of the organic contaminants are volatile and would be emitted to theatmosphere through agitation caused by aeration equipment. Therefore, biologicaltreatment will not be retained.

2.3.7.3 Precipitation, Flocculation, and Sedimentation

Precipitation, flocculation, and sedimentation are processes that have been used totreat various municipal and industrial wastewaters containing suspended solidsand/or soluble metals. Due to the filtering action of the soil, the presence ofsuspended solids is generally not a problem in groundwater leachate at theBlosenski Landfill Site, and the metals concentrations at the site are generallybelow the National Primary Drinking Water Standards. However, precipitation,

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flocculation, and sedimentation may be required for pretreatment in a system fortreatment of organic contaminants, such as carbon adsorption or air stripping.

2.3.7.4 Air Stripping

Air stripping has been demonstrated to remove various types of volatile organics,such as the chlorinated and aromatic hydrocarbons found in the groundwater at theBlosenski Landfill Site. Air stripping is a flexible process that can be designed toremove at least 90 percent of volatile organics. Air stripping is usually carried outin packed towers.

There is a possibility of exceeding ambient air standards due to volatilization ofcontaminants. However, this can be controlled by using proper operationalequipment. The overall cost of air stripping is lower than for carbon adsorption,even though operational costs for air stripping (electricity) is higher. Air strippingwill be retained for further evaluation.

2.3.7.5 Offsite Wastewater Treatment

The possibility of using a nearby publicly owned treatment works (POTW) forremoval of groundwater contaminants was investigated. The main consideration isthe cost effectiveness of designing and building an onsite treatment plant versussending the wastewater to the nearest POTW. In this case, the nearest POTW isthe City of Coatesville Treatment Plant, which is located approximately 6 milesfrom the site. Even if the plant has the required capacity, numerous institutionalconsiderations must be made regarding community responsibility and futuregrowth. POTWs are often reluctant to accept wastewaters that are not generatedwithin their jurisdictional area. Nevertheless, treatment at a POTW should beretained for further consideration.

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2.3.8 Onsite Storage

Storage measures merely transfer the wastes from one location to another and donot meet the objective of reducing corresponding risk to acceptable levels.Temporary stor