rules of department of natural resources10 csr 20-8.190 disinfection ... cover page. include a...

CODE OF STATE REGULATIONS 1JOHN R. ASHCROFT (1/29/19)Secretary of State

Rules ofDepartment of Natural Resources

Division 20—Clean Water CommissionChapter 8—Minimum Design Standards

Title Page

10 CSR 20-8.010 Design of Municipal Waste Stabilization Lagoons in Missouri(Rescinded August 13, 1979)................................................................3

10 CSR 20-8.020 Design of Small Sewage Works (Rescinded February 28, 2019) ......................3

10 CSR 20-8.021 Individual Sewage Treatment Systems Standards (Rescinded March 30, 1999) .....3

10 CSR 20-8.030 Design of Sewage Works (Rescinded August 13, 1979) .................................3

10 CSR 20-8.110 Engineering—Reports, Plans, and Specifications .........................................3

10 CSR 20-8.120 Gravity Sewers ..................................................................................8

10 CSR 20-8.125 Alternative Sewer Systems ....................................................................9

10 CSR 20-8.130 Pumping Stations..............................................................................10

10 CSR 20-8.140 Wastewater Treatment Facilities ............................................................12

10 CSR 20-8.150 Preliminary Treatment........................................................................15

10 CSR 20-8.160 Settling ..........................................................................................16

10 CSR 20-8.170 Solids Handling and Disposal...............................................................17

10 CSR 20-8.180 Biological Treatment..........................................................................18

10 CSR 20-8.190 Disinfection ....................................................................................19

10 CSR 20-8.200 Wastewater Treatment Lagoons and Wastewater Irrigation Alternatives .............20

10 CSR 20-8.210 Supplemental Treatment......................................................................23

10 CSR 20-8.220 Land Treatment (Rescinded February 28, 2019).........................................24

10 CSR 20-8.300 Design of Concentrated Animal Feeding Operations....................................24

10 CSR 20-8.500 Design Requirements for Agrichemical Facilities .......................................27

Title 10—DEPARTMENT OFNATURAL RESOURCES

Division 20—Clean Water CommissionChapter 8—Minimum Design Standards

10 CSR 20-8.010 Design of MunicipalWaste Stabilization Lagoons in Missouri(Rescinded August 13, 1979)

AUTHORITY: section 204.026, RSMo Supp.1973. Original rule filed July 17, 1961, effec-tive July 27, 1961. Amended: Filed Oct. 3,1962, effective Oct. 13, 1962. Amended:Filed Dec. 4, 1975, effective Dec. 14, 1975.Rescinded: Filed May 4, 1979, effective Aug.13, 1979.

10 CSR 20-8.020 Design of Small SewageWorks (Rescinded February 28, 2019)

AUTHORITY: section 644.026, RSMo Supp.1988. Original rule filed July 17, 1961, effec-tive July 27, 1961. Amended: Filed Oct. 3,1962, effective Oct. 13, 1962. Amended:Filed Dec. 4, 1975, effective Dec. 14, 1975.Rescinded and readopted: Filed Nov. 4,1988, effective April 15, 1989. Rescinded:Filed June 15, 2018, effective Feb. 28, 2019.

10 CSR 20-8.021 Individual Sewage Treat-ment Systems Standards(Rescinded March 30, 1999)

AUTHORITY: section 644.026, RSMo 1986.Original rule filed Nov. 14, 1988, effectiveApril 15, 1989. Rescinded: Filed July 13,1998, effective March 30, 1999.

10 CSR 20-8.030 Design of Sewage Works(Rescinded August 13, 1979)

AUTHORITY: section 204.026, RSMo Supp.1973. Original rule filed July 17, 1961, effec-tive July 27, 1961. Amended: Filed Oct. 3,1962, effective Oct. 13, 1962. Amended:Filed Dec. 4, 1975, effective Dec. 14, 1975.Rescinded: Filed May 4, 1979, effective Aug.13, 1979.

Op. Atty. Gen. No. 92, Bockenkamp (3-24-75). The City of Farmington may impose usercharges pursuant to section 204.026(18),RSMo (Supp. 1973), to cover costs of opera-tion and/or future expansion of a publicsewer treatment facility constructed pursuantto a grant of federal funds under 33 USC,Sections 1281-1292, without the necessity ofan election as provided in section 71.715,RSMo (1969).

Op. Atty. Gen. No. 229, Smith (8-20-73).Municipalities and sewer districts haveauthority to make the user charges to indus-tries required by the Federal Water PollutionControl Act amendments of 1972 and toestablish the reserves for future expansion orreconstruction.

10 CSR 20-8.110 Engineering—Reports,Plans, and Specifications

PURPOSE: This rule provides the minimumcriteria for the preparation of engineeringreports and facility plans and specificationsrelated to the design of wastewater systems.This rule is to be used with rules 10 CSR 20-8.110 through 10 CSR 20-8.210 for the plan-ning and design of a wastewater treatmentfacility. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

(1) Applicability. Engineering reports andfacility plans and specifications shall be pre-pared based on criteria contained in this rule,published standards, applicable federal andstate requirements, standard textbooks, cur-rent technical literature, and applicable safe-ty standards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.

(A) This rule shall not apply to treatmentunits covered in 10 CSR 20-8.300.

(B) This rule shall not apply to treatmentunits covered in 10 CSR 20-8.500.

(2) General. All documents submitted to theMissouri Department of Natural Resources(department) for the purpose of complyingwith this rule shall be prepared, signed,sealed, and dated by a Missouri registeredprofessional engineer.

(A) Submittal. The design engineer mustsubmit a project engineering report or facili-ty plan to the department and receive depart-ment approval prior to submitting permitapplications, plans, specifications, and fees.

(B) Engineering Reports or Facility Plans.1. Engineering reports must be complet-

ed for projects involving collection systems,pumping stations, and force mains.

2. Facility plans must be completed forprojects involving wastewater treatment facil-ity projects and projects receiving departmentfunding through the grant and loan programsunder 10 CSR 20-4, Grants and Loans.

(C) Approval. Engineering report or facili-ty plan approval does not authorize construc-tion.

(3) Hydraulic and Organic Waste Load.(A) Existing Systems shall—

1. Use actual flow data that accuratelyrepresent the average and peak flows to cal-culate projections for hydraulic capacity;

2. Include contributions from existingupstream combined sewers that will affectinterceptor sewers and treatment facilities;

3. Use actual data that accurately repre-sent organic waste load to calculate projec-tions for organic capacity; and

4. Include documented hydraulic andorganic waste load contributions of industrialsources in the calculations of projectedcapacity.

(B) New Collection and Wastewater Treat-ment Systems.

1. Hydraulic capacity for wastewaterfacilities and new collection systems.

A. Flow estimates for the design aver-age flow and design peak hourly flow, includ-ing origin of the flow estimates and anyassumptions, shall be identified.

B. Peaking factor. The average designflow value shall be used in conjunction witha peaking factor from the following Equation110-1, included herein.

Equation 110-1. Ratio of peak hourly flow todesign average flow.

Peaking Factor = Q Peak Hourly / Q DesignAvg = (18 + √P) / (4 + √P)

Where:Q Peak Hourly = design peak hourly flowQ Design Avg = design average flowP = Population in thousands

C. Where the new collection system isto serve existing development, the likelihoodof inflow and infiltration (I/I) contributionsfrom existing service lines shall be evaluated.

2. Organic Waste Load. Organic wasteload estimates shall be identified for all con-tributing parameters such as the design aver-age five (5)-day Biochemical OxygenDemand (BOD5).

(C) Drinking Water Use Records. Facilitiesproposing drinking water usage as the basisfor design average flow must provide at leastone (1)-year of drinking water use records inthe following form:

1. A minimum of twelve (12) continuousmonths of drinking water use records forfacilities that discharge year-round; or

2. A minimum of continuous daily wateruse records during the entirety of an operat-ing season for facilities having critical opera-tional schedules (e.g., recreational areas,campuses, and industrial facilities).

(D) Re-Rating a Wastewater Treatment


Chapter 8—Minimum Design Standards 10 CSR 20-8

Facility. A wastewater treatment facilityowner must request department review andapproval when proposing to re-rate an exist-ing wastewater treatment facility’s currentdesign hydraulic capacity or organic wasteloading. An engineering re-rating analysismust demonstrate the wastewater treatmentfacility can reliably operate at the proposedre-rated loading rate. The re-rating analysisshall include the following:

1. Hydraulic Capacity. Evaluate theannual average flow, the maximum monthlyaverage flow, the maximum daily flow, andthe ratio of the peak flow to annual averageflow using the last five (5) years’ wastewatertreatment facility. Include all calculations andassumptions.

A. Calculate the design average flowusing the wastewater treatment facility’s aver-age annual flow plus one (1) standard devia-tion for a wastewater treatment facility thatwill not be affected by future growth; or

B. Calculate the design average flowusing the anticipated changes from the exist-ing flow for a wastewater treatment facilitythat will be affected by future growth.

2. Organic Waste Load. Evaluate thedesign organic waste loading based on theaverage daily organic load.

A. Include the data from the analysesof at least three (3) twenty-four (24)-hourcomposite samples of the influent wastewaterper week, taken during days with representa-tive flow, for a period of at least three (3)months during both wet and dry weather con-ditions;

B. Include sample data of the follow-ing parameters unless monitoring of theparameter is not a requirement of the Nation-al Pollutant Discharge Elimination System(NPDES) permit: BOD5, Total SuspendedSolids (TSS), ammonia, total nitrogen, andtotal phosphorus;

C. Include the influence of hydrauliccapacity evaluation from subparagraph(3)(D)1.A and B. of this rule; and

D. Evaluate the size of each unit pro-cess to determine if they are appropriatelysized to provide adequate treatment based onthe re-rated design organic waste load.

3. Existing unit processes. Evaluateeach unit process for its design and peakcapacity. Normally one (1) unit process willbe most restrictive in terms of design capaci-ty. Include solids processing, handling, andstorage in this analysis.

4. Compliance. Evaluate the proposedchange of the facility’s ability to reliably andconsistently comply with the NPDES permiteffluent limitations and conditions.

5. Growth. Evaluate the system’s antici-pated rate of growth.

(4) Engineering Report. Engineering reportsshall include the following:

(A) Cover Page. Include a statement iden-tifying the owner and continuing authority(refer to 10 CSR 20-6.010(2)(A)), a contactperson for each (including phone number andaddress), and engineer in accordance withsection (2) of this rule;

(B) Problem Defined. Include a descrip-tion of the existing system and an evaluationof the conditions and problems needing cor-rection;

(C) Hydraulic Capacity and Organic WasteLoad. Establish the anticipated design aver-age and design peak flows and organic loadsfor the existing and ultimate conditions.Include the basis of the projection reflectingthe existing or initial service area, and theanticipated future service area. More detailon flow and organic waste load informationand data needed for new and existing collec-tion systems are included in section (3) of thisrule;

(D) Impact on Existing Wastewater Facili-ties. Evaluate the impact of the proposed pro-ject on downstream existing wastewater sys-tems (including gravity sewers, alternativesewers, pumping stations, force mains, andtreatment facilities);

(E) Project Description. Provide a writtendescription of the project;

(F) Location Drawings. Provide drawingsidentifying the site of the project and antici-pated location and alignment of proposedfacilities;

(G) Engineering Criteria. Include designcriteria for the proposed project;

(H) Site Information. Provide project siteinformation, where applicable, includingtopography, soils, geologic conditions, depthto bedrock, groundwater level, distance towater supply structures, roads, residences,and other pertinent site information;

(I) Alternative Selection. Discuss the rea-sons for selection of the proposed alternative,including any pumping station sites, feasibil-ity, and how the project fits into a long termplan; and

(J) For flood protection follow the provi-sions listed in 10 CSR 20-8.140(2)(B).

(5) Facility Plan. Facility plans shall includethe following, in addition to the informationin section (4) of this rule:

(A) Planning and Service Area. Include adescription or drawings of the planning area,existing and potential future service areas, thesite of the project, and anticipated location ofthe proposed facilities;

(B) Population Projection and PlanningPeriod. Base the present and predicted popu-lation on a twenty (20)-year planning period.

Consider phased construction of wastewaterfacilities in rapid growth areas. Design sew-ers and other facilities with a design life inexcess of twenty (20) years for the extendedperiod;

(C) Wastewater Treatment Facility DesignCapacity. The wastewater treatment facilitydesign capacity is the design average flow atthe design average BOD5. Establish the antic-ipated design average and design peak flowsand waste loads for the existing period inaccordance with section (3) of this rule.Include the basis of the projection of initialand future flows and waste loads;

(D) Initial Alternative Development. Dis-cuss the process of selection of wastewatertreatment alternatives for detailed evaluation.Include all wastewater management alterna-tives considered, including no action, and thebasis for the engineering judgment for selec-tion of the alternatives chosen for detailedevaluation;

(E) Detailed Alternative Evaluation.Include the following for the alternatives tobe evaluated in detail:

1. Collection system revisions. Evaluatethe proposed revisions to the existing collec-tion system including adequacy of portionsnot being changed by the project;

2. Wet weather flows. Provide facilitiesto transport and treat wet weather flows in amanner that complies with federal, state, andlocal regulations;

3. Evaluate the no-discharge option andinclude it as an alternative in the facility plan.Also refer to 10 CSR 20-6.010(4)(A)5;

4. Evaluate the regionalization optionand include it as an alternative in the facilityplan;

5. Include the information outlined in 10CSR 20-8.200(2) when the project includeswastewater irrigation or subsurface soil dis-persal;

6. Site Evaluation. Consider the follow-ing criteria during site evaluation. Takeappropriate measures to minimize adverseimpacts when a site is critical with respect tothe following items:

A. Consider compatibility of thetreatment process with the present andplanned future land use, including noise,potential odors, air quality, and anticipatedsolids processing and disposal techniques.Wastewater treatment facilities should be sep-arate from habitation or any area likely to bebuilt up within a reasonable future period andshall be separated in accordance with stateand local requirements. Refer to 10 CSR 20-8.140(2)(C) for minimum separation dis-tances;

B. Identify zoning and other land userestrictions;

4 CODE OF STATE REGULATIONS (1/29/19) JOHN R. ASHCROFT

Secretary of State

10 CSR 20-8—DEPARTMENT OF NATURAL RESOURCES Division 20—Clean Water Commission

C. Evaluate the accessibility andtopography of the site;

D. Identify areas for future facilityexpansion;

E. For flood protection, follow theprovisions listed in 10 CSR 20-8.140(2)(B);

F. Include geologic information,depth to bedrock, karst features, or othergeologic considerations of significance to theproject;

G. A request for a geohydrologic eval-uation conducted by the department’s Mis-souri Geological Survey is required in the fol-lowing instances:

(I) All new wastewater treatmentfacilities to identify stream determinations(gaining or losing);

(II) All new outfalls or relocatedoutfalls;

(III) All new or major modifica-tions to earthen basin structures. Earthenbasin structures shall not be located in areasreceiving a severe collapse potential rating.Earthen basin structures located in areasreceiving a severe overall geologic limitationrating are reviewed on a case-by-case basis.Earthen basin structures located in areasreceiving a moderate collapse potential ratingwith an appropriate engineering solution arereviewed on a case-by-case basis; and

(IV) All new features (e.g. wastew-ater irrigation sites, subsurface soil dispersalsites);

H. Protection of groundwater includ-ing public and private wells shall be provid-ed. When the proposed wastewater facilitieswill be near a water source or other drinkingwater facility, as determined by the MissouriGeological Survey or by the department’sPublic Drinking Water Branch, include anevaluation addressing the allowable distancebetween these wastewater facilities and thewater source. Refer to 10 CSR 20-8.140(2)(C);

I. Determine the soil type and suit-ability for construction and depth to normaland seasonal high groundwater;

J. Submit a soil morphology analysisconducted by a qualified soil scientist for allsubsurface soil dispersal systems. Refer tosection (7) of this rule;

K. Identify the location, depth, anddischarge point of any field tile or curtaindrain in the immediate area of the proposedsite;

L. Include the present and knownfuture effluent quality and monitoringrequirements;

M. Provide a discussion of receivingwaterbody access for the outfall line; and

N. Include a preliminary assessmentof site availability;

7. Engineering criteria. Provide theengineering criteria and assumptions used inthe design of the project. Provide the basisfor unit operation and preliminary unit pro-cess sizing;

8. Location Drawings. Provide drawingsidentifying the site of the project and antici-pated location and alignment of proposedfacilities;

9. Flow diagram. Provide a preliminaryflow diagram of treatment facility alterna-tives, including all recycle flows;

10. Removal efficiencies. Provide esti-mated loadings to and removal efficienciesthrough each unit operation in addition tototal removal efficiency and effluent quality(both concentrations and mass);

11. Emergency operation. Provide a dis-cussion of emergency operation measures asoutlined in 10 CSR 20-8.140(7)(A);

12. New and innovative technology. Seesection (6) of this rule. Provide a contingen-cy plan, in the event that such new technolo-gy fails to meet the expected performance;

13. Nutrient removal. Provide a discus-sion of nutrient removal capabilities, includ-ing the footprint available for expansion ortreatment facility modifications necessary fornutrient removal for each alternative;

14. Solids. Include the solids handlingand disposal alternatives considered andmethod selected consistant with the require-ments of 10 CSR 20-8.170 and any condi-tions in the NPDES permit;

15. Treatment during construction.Develop a plan for the method and level oftreatment (including solids processing, stor-age, and disposal) to be achieved during con-struction and include it in the facility plan.Refer to paragraph (9)(A)5. and subsection(10)(C) of this rule;

16. Cost estimates. Present cost esti-mates for capital construction cost, annualoperation and maintenance cost (includingbasis), and a twenty (20)-year present worthcost for each alternative;

17. Environmental review. Include anyadditional environmental information meet-ing the criteria in 10 CSR 20-4.050, for pro-jects receiving funding through the state grantand loan programs; and

18. Water quality reports. Submit allreviews, studies, or reports in accordancewith 10 CSR 20-7, Water Quality; and

(F) Final Project Selection. Presentthe selected project from the alternatives con-sidered under paragraph (5)(E) of this rule,including the financing considerations andrecommendations for implementation of theplan. Provide a project implementationschedule identifying project milestones.

(6) New and Innovative Technology.(A) Evaluation of Technology Perfor-

mance. To determine if new technologies ofwastewater treatment processes and equip-ment or applications have a reasonable andsubstantial chance of success, the facility planprepared for department approval shallinclude the following:

1. Monitoring observations, includingtest results and engineering evaluationsdemonstrating the efficiency of processes orequipment;

2. Detailed description of the samplingprotocol and test methods that are sufficient-ly sensitive analytical methods for detecting,identifying, and measuring the concentrationsof pollutants;

3. Testing, including appropriately-com-posited samples, under various ranges ofstrength and flow rates (including diurnalvariations) and waste temperatures over a suf-ficient length of time to demonstrate expect-ed performance under the range of climaticand other conditions that may be encounteredin the area of the proposed installations. Acontrol group may be necessary to demon-strate effectiveness;

4. Description of manufacturer’s war-ranty and performance warranty including allexclusions or limitations on the warranty,when available;

5. Complete design requirements, calcu-lations, and all assumptions clearly docu-mented and explained;

6. Documentation of how the new pro-cess or equipment functions;

7. A discussion of actual, full-scaleoperating experience or pilot test work. Forfull-scale operating experience, include thelength of time that each installation has beenin operation. For pilot test work, include acopy of the associated pilot test plan and finalpilot test results report;

8. Discussion of known or anticipatedstart-up issues and operational issues thathave occurred or may occur during the firstyear of operation;

9. A description of specific operatorknowledge and skills needed to operate theproposed technology including an estimate ofincreased operator attention needed duringstart-up and the first year of operation; and

10. Other appropriate information.(B) Pilot Test or Demonstration Plan. Pro-

posals for pilot tests and demonstration pro-jects shall include the following in addition tothe facility plan information in section (5) ofthis rule:

1. Goals, objectives, and benefits withan explanation as to why a pilot study ordemonstration project is necessary to obtainadditional engineering data;



2. Literature identifying key designparameters and related experience;

3. A description of the proposal withschematic diagrams, pictures, drawings, orany other important information;

4. Complete design requirements, calcu-lations, and all assumptions clearly docu-mented and explained;

5. Identification of associated environ-mental impacts, both direct and indirect;

6. Detailed description of the samplingprotocol and test methods that are sufficient-ly sensitive analytical methods for detecting,identifying, and measuring the concentrationsof pollutants;

7. Complete schedule for testing andevaluation including start, completion, andsubmittal of the pilot test or demonstrationresults report; and

8. Other appropriate information.(C) Evaluation of Collected Data. All raw

testing data and the evaluation of the data andperformance must be submitted for depart-ment review upon conclusion of the projectdemonstration. The evaluation shall identifyand justify the removal of any excursions notrepresentative of the new technology processor equipment from the data evaluation.

(7) Soils Report.(A) Soils. Soil reports are required for all

projects involving subsurface wastewatertreatment and disposal. All soils investiga-tions and resulting reports must be per-formed, signed, and dated by a qualified soilscientist as defined in section 701.040,RSMo. Soil observation pits (i.e., backhoe orhand dug) excavated to a depth to reveal themajor soil horizons shall be utilized.

(B) Soils Report. The soils report resultingfrom the investigation shall include the fol-lowing information:

1. A copy of each soil profile descrip-tion;

2. A description of all drainage features,rock outcrops, erosion, and other natural fea-tures that may influence the soil treatmentarea;

3. An evaluation of any identified limit-ing conditions or geologic risk factors affect-ing the soil’s ability to treat and disperseeffluent, such as karst features, dense tills,clay pans, and fragipans;

4. Clear and legible scaled site plans,drawings, or maps identifying all applicablesite features that could impact the soil treat-ment area(s). Previously prepared or other-wise available drawings or maps such as asurvey prepared by a Missouri registered pro-fessional surveyor; an aerial photograph; aUnited States Geological Survey topographicmap with the proposed soil treatment area

clearly delineated; a United States Depart-ment of Agriculture Natural Resources Con-servation Services county soil survey mapwith the proposed soil treatment area clearlydelineated; or a digital orthophotograph pre-pared from a geographical information sys-tem may be used. The following shall beincluded on the drawings or maps:

A. The location of all soil observationpits with the extent of different soils clearlydelineated;

B. Any existing or proposed dwellingsand structures;

C. Any site disturbances such as exca-vated or fill areas, existing roadways, andother hardscapes and proposed hardscapes,or related site disturbances;

D. Location of all public and privatewells, abandoned wells, or geothermal sys-tems, and surface water features that couldeither influence or be impacted by the pro-posed soil treatment area. For minimum sep-aration distances, follow the provisions listedin 10 CSR 20-8.140(2)(C);

E. North orientation arrow;F. Identification of areas with condi-

tions that would prohibit, limit, or adverselyimpact the siting of a soil treatment areaincluding, but not limited to: sinkholes, wet-land vegetation, bedrock outcrops, areas witha slope greater than fifteen percent (15%),and existing or abandoned field or drainagetiles;

G. Identification of known existing,proposed, and observed easements and right-of-ways; and

5. A discussion of the findings and con-clusions must include the following:

A. Available area for the soil treat-ment area;

B. Depth to limiting layers (e.g.,water table, fragipan, bedrock) and thesource of this information;

C. Proposed application (loading)rates that take into consideration the drainageand permeability of the soils and the distanceto the limiting layer.

D. The source of the application ratesfor each soil horizon within the specific soildescription;

E. Frequency of flooding and pondingand the source of this information;

F. Relevant characteristics (e.g.,bedrock outcrops, sinkholes or karst features)on the proposed site or in the surroundingarea that may indicate vulnerability for sur-face water and groundwater contaminationand the source of this information; and

G. Factors affecting the soils abilityto treat and hydrologically control effluentand the source of this information.

(C) Imported Soils. When a facility is

importing soils for the subsurface soil disper-sal systems, the following shall be specified:

1. Physical characteristics that are uni-form in texture, structure, and pore space;

2. Transportation methods that ensuresuniformity and consistency of the physicalcharacteristics as close as possible to theoriginal state upon delivery;

3. A sandy to loamy material, with lessthan ten percent (10%) clay and less than fif-teen percent (15%) organic debris present;

4. Methods for removal of the organiclayer;

5. No compaction of imported soil;6. Placement in small “lift” increments

of four to six inches (4"–6") instead of one(1) thick layer; and

7. Native soil is to be used for the verti-cal separation for the subsurface soil disper-sal systems with the fill for the cap beingimported soils.

(8) Summary of Design. A summary ofdesign shall accompany the plans and specifi-cations and must include the following:

(A) Flow and waste projections includingdesign and peak hydraulic and organic load-ings for sewers, pump stations, and wastewa-ter treatment facilities;

(B) Information to verify adequate down-stream capacity of sewers, pump stations, andwastewater treatment and solids handlingunit(s);

(C) Type and size of individual processunits including the following: unit dimen-sions; rates and velocities; detention times;concentrations; recycle; chemical additivecontrol; physical control, flexibility, and flowmetering;

(D) Process diagrams, including flow dia-grams with hydraulic capacity and organicwaste load;

(E) Expected removal rates and concentra-tions of permitted effluent parameters in thedischarge from the wastewater treatmentfacility, including a separate tabulation foreach unit to handle solid and liquid fractions;

(F) Design calculations, tabulations, andassumptions clearly documented andexplained from 10 CSR 20-8.120 through 10CSR 20-8.210 used in the design of each unitprocess and the system(s) as a whole;

(G) The appropriate pump curve with thesystem curve superimposed, as applicable;

(H) Unusual specifications, constructionmaterials, and construction methods; maps,photographs, diagrams; and other supportdata needed to describe the system;

(I) Architectural, structural, and mechani-cal component design calculations as speci-fied in 10 CSR 20-8.120 through 10 CSR 20-8.210; and


Secretary of State


(J) Anticipated effluent quality.

(9) Plans.(A) General.

1. Plan components must include thefollowing components on all plan sheets:

A. A suitable title block showing thename of the project, owner, and continuingauthority (refer to 10 CSR 20-6.010(2) and20 CSR 2030-2.050);

B. Scale ratios for mechanical draw-ings;

C. Bar scales for aerial maps;D. A north arrow;E. Datum used; andF. Sheet numbers.

2. Plan format must include clear andlegible plans drawn to a scale that allows nec-essary information to be seen plainly.Blueprints and hand-drafted plans are notacceptable.

3. Plan contents must include detailedplans consisting of the following:

A. Plan views, elevations, sections,and supplementary views, which togetherwith the specifications and general layouts,provide the working information for the con-tract and construction of the facilities;

B. Dimensions and relative elevationsof structures, the location and outline form ofequipment, location and size of piping, waterlevels, and ground elevations;

C. All known existing structures andutilities, both above and below ground, thatmight interfere with the proposed construc-tion or require isolation setback, particularlywater mains and water supply structures(e.g., wells, clear wells, basins), gas mains,storm drains, and telephone, cable, andpower conduits. Show the location of allexisting and proposed water supply structureslocated within five hundred feet (500') of theproposed or existing wastewater treatmentfacility; and

D. Locations and logs of test borings,where applicable. Include test boring logs onthe plans or in the specifications as anappendix.

4. Hydraulic profile for all wastewatertreatment facilities must be included; and

5. Plan for operation during construc-tion must specify the procedure for operationduring construction that complies with theplan outlined in paragraph (5)(E)15. and sub-section (10)(C) of this rule.

(B) Plans of Sewers.1. General plans. These plans shall show

the following:A. Geographical features.

(I) Topography and elevations.Clearly show existing or proposed streets andall streams or water surfaces. Include contour

lines at suitable intervals;(II) Streams. Depict the direction of

flow in all streams and high and low waterelevations of all water surfaces;

(III) Boundaries. Depict the bound-ary lines of the continuing authority and thearea to be sewered; and

B. Sewers. Show the location, size,and direction of flow of relevant existing andproposed sanitary and combined sewersdraining to the treatment facility concerned.

2. Detail plans. Detail plans shall besubmitted showing the following:

A. Profiles having a horizontal scaleof not more than one hundred feet (100') tothe inch and a vertical scale of not more thanten feet (10') to the inch;

B. Plan views drawn to a correspond-ing horizontal scale and shown on the samesheet;

C. Location of streets and sewers;D. Line of ground surface; pipe size,

material, and type; length between manholes;invert and surface elevation at each manhole;grade of sewer between each two (2) adjacentmanholes; and any special construction fea-tures. Number all manholes on the plan andcorrespondingly number them on the profile;

E. Elevation and location of the base-ment floor on the profile of the sewer wherethere is any question of the sewer being suf-ficiently deep to serve any residence;

F. Locations of all special features,such as inverted siphons, concrete encase-ments, elevated sewers, etc.; and

G. Detail drawings to show the fol-lowing:

(I) All stream crossings with eleva-tions of the stream bed and ordinary highwater mark, normal, and low water levels;

(II) Details of all special sewerjoints and cross-sections; and

(III) Details of all sewer appurte-nances such as manholes, inspection cham-bers, inverted siphons, regulators, tide gates,and elevated sewers.

(C) Plans of Wastewater Pumping Stations.1. Location plans. These plans must

show the following:A. The location and extent of the trib-

utary area;B. Any continuing authority bound-

aries with the tributary area; C. The location of the pumping sta-

tion and force main; and D. Pertinent elevations.

2. Detail plans. Detail plans shall showthe following, where applicable:

A. Topography of the site;B. Existing pumping station;C. Proposed pumping station, includ-

ing provisions for installation of future

pumps;D. Maximum elevation of wastewater

in the collection system upon occasion ofpower failure;

E. Maximum hydraulic gradient indownstream gravity sewers when all installedpumps are in operation;

F. Test boring and groundwater eleva-tions;

G. All pumping station appurtenancessuch as pumps, valves, level control switches,hatches, safety equipment, ventilation equip-ment, and hoisting equipment; and

H. Flood protection map. For floodprotection, follow the provisions listed in 10CSR 20-8.140(2)(B).

(D) Plans of Wastewater Treatment Facili-ties.

1. Location plans. Location plans shallinclude the following:

A. The wastewater treatment facilityin relation to the remainder of the system;and

B. Sufficient topographic features toindicate its location with relation to streamsand the point of discharge of treated effluent.

2. General layout. Layouts of the pro-posed wastewater treatment facility shallshow—

A. Topography of the site;B. Size and location of treatment

facility structures;C. Schematic flow diagram(s) show-

ing the flow through various units and show-ing utility systems serving the facility pro-cesses;

D. Piping, including any arrangementfor unit isolation (identify materials handledand direction of flow through pipes, includingarrangements for independent operation);

E. Hydraulic profiles showing theflow of wastewater, supernatant liquor, recy-cle streams, and solids; and

F. Test borings and groundwater ele-vations.

3. Detail plans. Detail plans shall showthe following, where applicable:

A. Location, dimensions, and eleva-tions of all existing and proposed treatmentfacilities and solids handling facilities;

B. Elevations of high and low waterlevel of the body of water to which the facil-ity effluent is to be discharged;

C. Type, size, pertinent features, andoperating capacity of all pumps, blowers,motors, and other mechanical devices;

D. Minimum, design average, andpeak hourly hydraulic flow in hydraulic pro-file with wastewater, supernatant liquor, andsolids flow through the treatment facility;

E. Existing and proposed solids stor-age volumes in plan and profile;



F. Adequate description of any fea-tures not otherwise covered by the specifica-tions or facility plan; and

G. Flood protection map. For floodprotection, follow the provisions listed in 10CSR 20-8.140(2)(B).

(10) Specifications.(A) Specifications shall accompany the

plans. The initial page shall bear the ownerand continuing authority name, and a contactperson for each (including phone number andaddress).

(B) The technical specifications accompa-nying construction drawings shall include thefollowing, but not be limited to all construc-tion information not shown on the drawingswhich is necessary to inform the builder, indetail, of the design requirements for thequality of materials, workmanship, and fabri-cation of the project:

1. The type, size, strength, operatingcharacteristics, and rating of equipment;

2. Allowable infiltration;3. The complete requirements for all

mechanical and electrical equipment (includ-ing machinery, valves, piping, and jointing ofpipe);

4. Electrical apparatus, wiring, instru-mentation, and meters;

5. Laboratory fixtures and equipment;6. Operating tools;7. Construction materials;8. Special filter materials (such as stone,

sand, gravel, or slag);9. Miscellaneous appurtenances;10. Chemicals when used;11. Instructions for testing materials and

equipment as necessary to meet design stan-dards; and

12. Performance tests for the completedfacilities and component units. It is suggestedthat these performance tests be conducted atdesign load conditions wherever practical.

(C) Operation During Construction. Spec-ifications shall contain a program for keepingexisting wastewater treatment facility units inoperation during construction. Should it benecessary to take units out of operation, spec-ifications shall include detailed constructionrequirements and schedules to maintain com-pliance with effluent limitations and the facil-ity’s NPDES permit. See paragraphs(5)(E)15. and (9)(A)5. of this rule.

(11) Revisions to Approved Plans or Specifi-cations.

(A) General. Any revisions of approvedplans or specifications affecting capacity,flow, system layout, operation of units, orpoint of discharge shall be approved by thedepartment in writing, before such changes

are made. (B) Addendum. Addenda must conform to

all requirements in this rule.(C) Change Order. The owner, continuing

authority, and contractor must sign and datechange orders.

(D) As-Built Plans. As-built plans clearlyshowing the alterations must be submittedupon department request at the completion ofthe work.

AUTHORITY: section 644.026, RSMo 2016.*Original rule filed Aug. 10, 1978, effectiveMarch 11, 1979. Amended: Filed Sept. 14,2010, effective June 30, 2011. Amended: FiledJune 15, 2018, effective Feb. 28, 2019.

*Original authority: 644.026, RSMo 1972, amended1973, 1987, 1993, 1995, 2000.

10 CSR 20-8.120 Gravity Sewers

PURPOSE: This rule specifies the minimumstandards for the design of gravity sewers thatare part of wastewater collection and treat-ment systems. This rule is to be used withrules 10 CSR 20-8.110 through 10 CSR 20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

PUBLISHER’S NOTE: The secretary of statehas determined that the publication of theentire text of the material which is incorpo-rated by reference as a portion of this rulewould be unduly cumbersome or expen-sive. This material as incorporated by refer-ence in this rule shall be maintained by theagency at its headquarters and shall be madeavailable to the public for inspection andcopying at no more than the actual cost ofreproduction. This note applies only to thereference material. The entire text of the ruleis printed here.

(1) Applicability. Wastewater systems that uti-lize gravity sewers shall be designed based oncriteria contained in this rule, published stan-dards, applicable federal and state require-ments, standard textbooks, current technicalliterature and applicable safety standards. Inthe event of any conflict between the abovecriteria, the requirement in this rule shall pre-vail.



(2) Sanitary Sewers. Rain water from roofs,

streets, and other areas and groundwaterfrom foundation drains shall be excludedfrom all new sewers.

(3) Details of Design and Construction.(A) Installation. Installation specifications

shall contain appropriate requirements basedon the criteria, standards, and requirementsestablished by industry in its technical publi-cations. Requirements shall be set forth in thespecifications for the pipe and methods ofbedding and backfilling thereof, so as not todamage the pipe or its joints, impede clean-ing operations, and future tapping, nor createexcessive side fill pressures and ovalation ofthe pipe, nor seriously impair flow capacity.

1. Slope. All sewers shall be designedand constructed to give mean velocities,when flowing full, of not less than two feet(2') per second.

2. Depth. All sewers shall either be cov-ered with at least thirty-six inches (36") ofsoil, or sufficiently insulated with othermaterial to prevent freezing and to protectthem from superimposed loads.

3. Buoyancy. Buoyancy of sewers shallbe considered and flotation of the pipe shallbe prevented with appropriate constructionwhere high groundwater conditions are antic-ipated.

(B) Deflection test. No pipe shall exceed adeflection of five percent (5%) of the insidediameter.

(C) Joints and Infiltration.1. Service connections. Service connec-

tions to the sewer main shall be watertightand cannot protrude into the sewer.

2. Leakage tests. Leakage tests shall bespecified for gravity sewers except polyvinylchloride (PVC) pipe with a diameter of twen-ty-seven inches (27") or less.

A. Water (hydrostatic) test. The leak-age exfiltration or infiltration shall not exceedone hundred (100) gallons per inch of pipediameter per mile per day for any sectionbetween manholes of the system. An exfiltra-tion or infiltration test shall be performedwith a minimum positive head of two feet(2’). The exfiltration or infiltration test shallconform to the test procedure described inASTM C969 – 17 Standard Practice for Infil-tration and Exfiltration Acceptance Testing ofInstalled Precast Concrete Pipe Sewer Lines,as approved and published April 1, 2017, forprecast concrete pipe. This standard shallhereby be incorporated by reference into thisrule, as published by ASTM International,100 Barr Harbor Drive, PO Box C700, WestConshohocken, PA 19428-2959. This ruledoes not incorporate any subsequent amend-ments or additions.

B. Air test. The air test shall conform


Secretary of State


to the test procedure described in ASTMC1103 – 14 Standard Practice for JointAcceptance Testing of Installed Precast Con-crete Pipe Sewer Lines, as approved and pub-lished November 1, 2014, for concrete pipetwenty-seven inches (27”) or greater in diam-eter, and ASTM F1417 – 11a(2015) StandardPractice for Installation Acceptance of PlasticNon-pressure Sewer Lines Using Low-Pres-sure Air, as approved and published August1, 2015, for plastic, composite, and ductileiron pipe. These standards shall hereby beincorporated by reference into this rule, aspublished by ASTM International, 100 BarrHarbor Drive, PO Box C700, West Con-shohocken, PA 19428-2959. This rule doesnot incorporate any subsequent amendmentsor additions.

(D) Bore or Tunnel. Where casing pipe isutilized it shall be constructed of steel withwelded joints conforming to AWWA C200-17Steel Water Pipe, 6 In. (150 mm) and Larger,as approved and published August 1, 2017,or ductile iron pipe with mechanical joints.This standard shall hereby be incorporated byreference into this rule, as published byAmerican Water Works Association(AWWA), 6666 West Quincy Avenue, Den-ver, CO 80235-3098. This rule does notincorporate any subsequent amendments oradditions.

(4) Manholes.(A) Location. Manholes shall be installed—

1. At the end of each line;2. At all changes in grade, size, or align-

ment;3. At all sewer pipe intersections; and4. At distances appropriate to allow for

sufficient cleaning and maintenance of sewerlines.

(B) Drop Type.1. A drop pipe shall be provided for a

sewer entering a manhole at an elevation oftwenty-four inches (24") or more above themanhole invert.

2. When using precast manholes, dropconnections must not enter the manhole at ajoint.

(C) Diameter. The minimum diameter ofmanholes shall be forty-two inches (42") oneight-inch (8") diameter gravity sewer linesand forty-eight inches (48") on all sewer lineslarger than eight inches (8") in diameter. Aminimum access diameter of twenty-twoinches (22") (56 cm) shall be provided.Cleanouts shall be a minimum of eight inch-es (8") for pipes eight inches (8") in diame-ter or larger and equal to the diameter forpipes less than eight inches (8").

(D) Bench. No sewer, service connection,or drop manhole pipe shall discharge onto the

surface of the bench.(E) Watertightness. Manholes shall be

watertight, constructed, and installed inaccordance with the manufacturer’s recom-mendations and procedures.

(F) Inspection and Testing. 1. Vacuum testing, if specified for con-

crete sewer manholes, shall conform to thetest procedures in ASTM C1244 – 11(2017)Standard Test Method for Concrete SewerManholes by the Negative Air Pressure (Vac-uum) Test Prior to Backfill, as approved andpublished April 1, 2017, or the manufactur-er’s recommendation. This standard shallhereby be incorporated by reference into thisrule, as published by ASTM International,100 Barr Harbor Drive, PO Box C700, WestConshohocken, PA 19428-2959. This ruledoes not incorporate any subsequent amend-ments or additions.

2. Exfiltration testing, if specified forconcrete sewer manholes, shall conform tothe test procedures in ASTM C969 – 17 Stan-dard Practice for Infiltration and ExfiltrationAcceptance Testing of Installed Precast Con-crete Pipe Sewer Lines, as approved and pub-lished April 1, 2017. This standard shallhereby be incorporated by reference into thisrule, as published by ASTM International,100 Barr Harbor Drive, PO Box C700, WestConshohocken, PA 19428-2959. This ruledoes not incorporate any subsequent amend-ments or additions.

(5) Protection of Water Supplies. (A) Cross Connections. There shall be no

physical connections between a public or pri-vate potable water supply system and a seweror appurtenance that would permit the pas-sage of any wastewater or polluted water intothe potable supply.

(B) Relation to Water Works Structures.Sewers shall be laid at least fifty feet (50') ina horizontal direction from any existing orproposed public water supply well or otherwater supply sources or structures. Sewersmust also comply with 10 CSR 23-3.010.

AUTHORITY: section 644.026, RSMo 2016.*Original rule filed Aug. 10, 1978, effectiveMarch 11, 1979. Amended: Filed May 17,1994, effective Dec. 30, 1994. Amended:Filed June 28, 2011, effective Feb. 29, 2012.Amended: Filed June 15, 2018, effective Feb.28, 2019.

*Original authority: 644.026, RSMo 1972, amended1973, 1987, 1993, 1995.

10 CSR 20-8.125 Alternative Sewer Systems

PURPOSE: This rule specifies the minimum

standards for the design of alternative sewersystems that are part of wastewater collectionand treatment systems. This rule is to be usedwith rules 10 CSR 20-8.110 through 10 CSR20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

(1) Applicability. Wastewater systems that uti-lize alternative sewer systems shall bedesigned based on criteria contained in thisrule, published standards, applicable federaland state requirements, standard textbooks,current technical literature, and applicablesafety standards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) Approval of Sewers. For sewer approval,follow the provisions listed in 10 CSR 20-8.120(2).

(3) Supplement to the Engineering Report.Alternative sewer systems shall not to be usedin lieu of conventional gravity sewers, butmay be acceptable when it can be shown inthe engineering report that it is not feasible toprovide conventional gravity sewers. Formore information, follow the provisions in 10CSR 20-8.110(4).

(4) General.(A) Continuing Authority. The continuing

authority must be responsible for the opera-tion and maintenance and modernization ofan alternative sewer system collection system.See 10 CSR 20-6.010(2) for acceptable con-tinuing authorities.

(B) Flooding. For flood protection, followthe provisions in 10 CSR 20-8.140(2)(B).

(C) Accessibility. For pumping stationstructure and septic tank accessibility, followthe provisions listed in 10 CSR 20-8.140(2)(D).

(D) Security. For fencing criteria, followthe provisions in 10 CSR 20-8.140(8)(A).

(E) Potable Water Sources. For the mini-mum separation distances from potable watersources, follow the provisions in 10 CSR 20-8.130(2)(D).

(F) Protection of Water Supplies. For theseparation and crossings of water supplies,follow the provisions in 10 CSR 20-8.120(5).

(5) Pressure Sewers.(A) Sewer Design.



1. Velocity. Design shall be based on themost probable number of pumping unitsexpected to operate simultaneously or onsome other acceptable method of computingthe peak pumpage rate.

A. A cleansing velocity of at least twofeet per second (2 ft/s), at least once andpreferably several times per day, shall beachieved.

2. Minimum size. The minimum diame-ter sewer main pipe shall not be less than oneand a half inches (1.5").

3. Installation. For sewer installation,follow the provisions in 10 CSR 20-8.120(3).

4. Hydrostatic pressure test. The appli-cant must comply with the manufacturer’srecommended testing procedures.

5. Locator Wire. Locator wire must beutilized when sewer lines are installed withinthe public right-of-way in accordance withSection 319.033, RSMo.

(B) Sewer Appurtenances. Appurtenancesshall be compatible with the piping systemand full bore with smooth interior surfaces toeliminate obstruction and keep friction loss toa minimum.

1. Isolation valves shall be—A. Comprised of resilient seated gate

valve or ball valve with a position indicator;B. Constructed from corrosion resis-

tant materials; andC. Enclosed in a watertight and lock-

able valve box.2. Isolation valves shall be installed on—

A. The upstream side of major pipeintersections;

B. Both sides of stream, bridge, andrailroad crossings, and unstable soil; and

C. The terminal end of the system tofacilitate future extensions.

3. Proper support (e.g., crushed stone,concrete pads, or a well compacted trenchbottom) shall be provided for valves so theweight of the valve is not carried by the pipe.

(C) Service Line Connection. The mini-mum diameter service line pipe shall be oneand one quarter inches (1.25").

(D) Grinder Pump Stations.1. Number of pumps.

A. Simplex grinder pump stationshall—

(I) Not serve multiple equivalentdwelling units (EDU) if owned, operated,and maintained by individual homeowners;and

(II) Not serve commercial facili-ties.

B. Multiple unit grinder pump sta-tions must be owned, operated, and main-tained by an approved continuing authority.See subsection (4)(A) of this rule for morecontinuing authority information.

2. Grinder pump vaults shall be water-tight.

3. Storage volume. A grinder pumpvault shall have a storage volume of at leastseventy (70) gallons.

4. Valves. The following valves must beprovided in the grinder pump vaults:

A. A shutoff valve accessible from theground surface;

B. A check valve to prevent backflow;and

C. An anti-siphon valve, wheresiphoning could occur.

5. Grinder pump construction. Fordesign of pumps and motors, follow the pro-visions in 10 CSR 20-8.130(5).

6. Controls. For water level controldesign, follow the provisions in 10 CSR 20-8.130(3)(C).

7. Electrical equipment. For electricalequipment, follow the provisions in 10 CSR20-8.130(3)(B)2.

8. Emergency operations. When the con-tinuing authority operates and maintains thegrinder pump stations, provisions must bemade for periods of mechanical or power fail-ure.

(6) Septic Tank Effluent Pumped (STEP)Sewers.

(A) Sewer Design. Follow the provisions insubsection (5)(A) of this rule.

(B) Sewer Appurtenances. Follow the pro-visions in subsection (5)(B) of this rule.

(C) Service Line Connection. Follow theprovisions in subsection (5)(C) of this rule.

(D) Septic Tank Design. Follow the provi-sions in 10 CSR 20-8.180(2). Additionally,septic tank design shall:

1. Provide at least one (1) septic tank toserve each EDU;

2. Provide at least one thousand (1,000)gallons capacity; and

3. Provide twenty percent (20%) of theseptic tank volume for freeboard and ventila-tion.

(E) Existing Septic Tanks. When existingon-site septic tanks are proposed for reuse inan alternative sewer system, they must beinspected and verified watertight prior toacceptance. Follow the provisions in subsec-tion (6)(D) of this rule for the minimumdesign of acceptable existing septic tanks pro-posed for reuse.

(F) Pump Vault Design. 1. Number of pumps. Duplex pumps

shall be provided where the design flow fromthe EDUs, or other, is one thousand five hun-dred (1,500) gallons per day or greater.

2. Pump removal. Follow the provisionsin 10 CSR 20-8.130(5)(A).

3. Valves. Follow the provisions in para-graph (5)(D)4. of this rule.

4. Controls. For water level controldesign, follow the provisions in 10 CSR 20-8.130(3)(C).

5. Electrical equipment. Follow the pro-visions in 10 CSR 20-8.130(3)(B)2.

6. Emergency operations. Provisionsmust be made for periods of mechanical orpower failure.

(7) Septic Tank Effluent Gravity (STEG)Sewers.

(A) Sewer Design. 1. Minimum size. The minimum diame-

ter sewer main pipe shall not be less than fourinches (4").

2. Installation. Follow the provisions in10 CSR 20-8.120(3)(A).

3. Leakage tests. Follow the provisionsin 10 CSR 20-8.120(3)(C)2.

(B) Sewer Appurtenances. Follow the pro-visions in subsection (5)(B) of this rule.When manholes are utilized at major junc-tions of sewer mains, follow the provisions in10 CSR 20-8.120(4).

(C) Service Line Connection. Follow theprovisions in subsection (5)(C) of this rule.

1. The diameter of service line pipeshall not be less than four inches (4").

(D) Septic Tank Design. Follow the provi-sions in subsections (6)(D) through (6)(E) ofthis rule.

(8) Combination of Sewers. A pressure sewersystem discharging to a downstream STEP orSTEG sewer system shall not be permitted, aseffluent sewers are not designed to carry set-tleable solids and grease.

AUTHORITY: section 644.026, RSMo 2016.*Original rule filed June 15, 2018, effectiveFeb. 28, 2019.

*Original authority: 644.026, RSMo 1972, amended1973, 1987, 1993, 1995, 2000.

10 CSR 20-8.130 Pumping Stations

PURPOSE: This rule specifies the minimumstandards for the design of pumping stationsthat are part of wastewater collection andtreatment systems. This rule is to be used withrules 10 CSR 20-8.110 through 10 CSR 20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

Editor’s Note: The secretary of state hasdetermined that the publication of this rule inits entirety would be unduly cumbersome orexpensive. The entire text of the material ref-erenced has been filed with the secretary of


Secretary of State


state. This material may be found at theOffice of the Secretary of State or at the head-quarters of the agency and is available to anyinterested person at a cost established bystate law.

(1) Applicability. Wastewater systems that uti-lize pumping stations shall be designed basedon criteria contained in this rule, publishedstandards, applicable federal and staterequirements, standard textbooks, currenttechnical literature, and applicable safetystandards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) General.(A) Flood Protection. For flood protection

follow the provisions in 10 CSR 20-8.140(2)(B).

(B) Access Road. For access roads to pumpstation sites follow the provisions in 10 CSR20-8.140(2)(D).

(C) Safety. For safety follow the applicableportions of 10 CSR 20-8.140(8).

(D) Potable Water Sources. The distancebetween wastewater pumping stations and allpotable water sources shall be at least fiftyfeet (50') in accordance with 10 CSR 23-3.010(1)(B).

(E) Housed Wet Wells. Housed wet wellventilation shall be in accordance with 10CSR 20-8.140(8)(J).

(3) Design.(A) Structures.

1. Separation. Dry wells, including theirsuperstructure, shall be completely separatedfrom the wet well with gas tight commonwalls.

2. Access. Suitable and safe means ofaccess to dry wells and to wet wells shall beprovided to persons wearing self-containedbreathing apparatus.

(B) Pumps.1. Multiple units. Multiple pumps shall

be provided except for design average flowsof less than fifteen hundred (1,500) gallonsper day.

2. Electrical equipment. Electricalequipment shall be provided with the follow-ing requirements:

A. Electrical equipment must complywith 10 CSR 20-8.140(7)(B);

B. Utilize corrosive resistant equip-ment located in the wet well;

C. Provide a watertight seal and sep-arate strain relief for all flexible cable;

D. Install a fused disconnect switchlocated above ground for the main power feedfor all pumping stations.

E. When such equipment is exposedto weather, it shall comply with the require-ments of weather proof equipment; enclosureNEMA 4; NEMA 4X, where necessary; andNEMA Standard 250-2014, published Decem-ber 15, 2014. This standard shall hereby beincorporated by reference into this rule, aspublished by National Electrical Manufactur-ers Association, 1300 North 17th Street,Arlington, VA 22209. This rule does notincorporate any subsequent amendments oradditions;

F. Install lightning and surge protec-tion systems;

G. Install a one hundred ten volt (110V) power receptacle inside the control panellocated outdoors to facilitate maintenance;and

H. Provide Ground Fault CircuitInterruption (GFCI) protection for all out-door receptacles.

(C) Controls. Water level controls must beaccessible without entering the wet well.

(D) Valves. Valves shall not be located inthe wet well unless integral to a pump or itshousing.

(E) Wet Wells. Covered wet wells shallhave provisions for air displacement to theatmosphere, such as an inverted and screened“j” tube or other means.

(F) Ventilation. Interconnection betweenthe wet well and dry well ventilation systemsis not acceptable. For ventilation follow theprovisions in 10 CSR 20-8.140(8)(J).

(G) Water Supply. There shall be no phys-ical connection between any potable watersupply and a wastewater pumping station,which under any conditions, might causecontamination of the potable water supply. Ifa potable water supply is brought to the sta-tion, it shall comply with conditions stipulat-ed under 10 CSR 20-8.140(7)(D).

(4) Suction Lift Pumps.(A) Self-Priming Pumps. The combined

total of dynamic suction lift at the “pumpoff” elevation and required net positive suc-tion head at design operating conditions shallnot exceed twenty-two feet (22').

(B) Vacuum Priming Pumps. Vacuumpriming pump stations shall be equipped withdual vacuum pumps capable of automaticallyand completely removing air from the suctionlift pump.

(C) Wet Well Access. Wet well access shallnot be through the equipment compartment.Access shall be provided in accordance withparagraph (3)(A)2. of this rule.

(5) Submersible Pump Stations. Submersiblepump stations shall meet the applicablerequirements under section (3) of this rule,except as modified in this section.

(A) Pump Removal. Submersible pumpsshall be readily removable and replaceablewithout personnel entering, dewatering, ordisconnecting any piping in the wet well.

(B) Valve Chamber and Valves. Valvesrequired under subsection (3)(D) of this ruleshall be located in a separate valve chamber.

1. Access. A minimum access hatchdimensions of twenty-four inches by thirty-six inches (24" x 36") shall be provided. Foraccess, follow the provisions in paragraph(3)(A)2. of this rule.

2. Portable pump connection. Aportable pump connection on the dischargeline with rapid connection capabilities shallbe provided.

(6) Alarm Systems. Alarm systems with anuninterrupted power source shall be providedfor pumping stations.

(7) Emergency Operation. (A) In addition to the required emergency

means of operation and a storage/detentionbasin or tank, the following minimum reten-tion time shall be provided:

1. For facilities with a design averageflow of one hundred thousand (100,000) gal-lons per day or greater, a storage capacity fortwo- (2-) hour retention of the peak hourlyflow; or

2. For facilities with a design averageflow of less than one hundred thousand(100,000) gallons per day, a storage capacityfor four- (4-) hour retention of the peakhourly flow.

(B) Independent Utility Substations.Where independent substations are used foremergency power, each separate substationand its associated distribution lines shall becapable of starting and operating the pumpstation at its rated capacity.

(8) Force Mains.(A) Design. Force main system shall be

designed to withstand all pressures (includingwater hammer and associated cyclic reversalof stresses), and maintain a velocity of atleast two feet (2') per second.

(B) Installation. For installation follow theprovisions in 10 CSR 20-8.120(3)(A).

(C) Protection of Water Supplies. For sep-aration between water mains and sanitarysewer force mains follow the provisions in 10CSR 20-8.120(5).

(D) Locator wire. For locator wire followthe provisions in 10 CSR 20-8.125(5)(A)5.



AUTHORITY: section 644.026, RSMo 2016.*Original rule filed Aug. 10, 1978, effectiveMarch 11, 1979. Amended: Filed June 15,2018, effective Feb. 28, 2019.

*Original authority: 644.026, RSMo 1972, amended1973, 1987, 1993.

10 CSR 20-8.140 Wastewater TreatmentFacilities

PURPOSE: This rule contains the minimumstandards for the design of systems that arepart of wastewater collection and treatmentsystems. This rule is to be used with rules 10CSR 20-8.110 through 10 CSR 20-8.210. Itdoes not address all possible aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.


(1) Applicability. Wastewater systems shall bedesigned based on criteria contained in thisrule, published standards, applicable federaland state requirements, standard textbooks,current technical literature, and applicablesafety standards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) General.(A) Location. Criteria to be considered

when selecting a site are listed in 10 CSR 20-8.110(5)(E)6.

(B) Flood Protection. Flood protectionshall apply to new construction and to exist-ing facilities undergoing major modification.The wastewater facility structures, electricalequipment, and mechanical equipment shallbe protected from physical damage by notless than the one hundred- (100-) year floodelevation.

(C) Minimum Separation Distances.

1. Potable water sources. Unless anoth-er distance is determined by the MissouriGeological Survey or by the department’sPublic Drinking Water Branch, the minimumdistance between wastewater treatment facili-ties and all potable water sources shall be atleast three hundred feet (300').

2. Residences. No treatment unit with acapacity of twenty-two thousand five hundredgallons per day (22,500 gpd) or less shall belocated closer than the minimum distanceprovided in Table 140-1 below. See 10 CSR20-2.010(68) for the definition of a residence.

3. Plant Location. The following itemsshall be considered when selecting a plantsite: proximity to residential areas; directionof prevailing winds; accessibility by all-weather roads; area available for expansion;local zoning requirements; local soil charac-teristics, geology, hydrology and topographyavailable to minimize pumping; access toreceiving stream; downstream uses of thereceiving stream and compatibility of thetreatment process with the present andplanned future land use, including noise,potential odors, air quality, and anticipatedsludge processing and disposal techniques.Where a site must be used which is criticalwith respect to these items, appropriate mea-sures shall be taken to minimize adverseimpacts.

(D) Accessibility. Facilities shall be readi-ly accessible by authorized personnel from apublic right-of-way at all times.

(3) Quality of Effluent. The degree ofwastewater treatment shall be based on 10CSR 20-7.015, Effluent Regulations, 10 CSR20-7.031, Water Quality Standards, and/orappropriate federal regulations including theprovisions of the operating permit.

(4) Pump and Haul.(A) General.

1. Accessibility. Conform to subsection(2)(D) of this rule.

2. Security. Follow the provisions insubsection (8)(A) of this rule for fencing.

3. Protection of water supplies. Separa-tion and crossing of water supplies shall be inaccordance with subsection (2)(C) of this ruleand 10 CSR 20-8.120(5).

(B) Septic Tank Design. Conform to 10CSR 20-8.180(2) for septic tank design.

(C) Earthen Basin Design. Follow the pro-visions in 10 CSR 20-8.200 for earthen basindesign.

(D) Alarm system. The alarm shall be acti-vated in cases of high water levels. Follow theprovisions in subsection (7)(C) of this rule foralarm systems.

(5) Design.(A) Type of Treatment. Items to be consid-

ered in selection of the appropriate type oftreatment are presented in 10 CSR 20-8.110(5).

(B) New and Innovative Technology. Fol-low the provisions in 10 CSR 20-8.110(6).

(C) Design Period. Identify the designperiod in the facility plan per 10 CSR 20-8.110(5)(B).

(D) Design Loads.1. Hydraulic design.

A. Identify flow conditions critical tothe design of the wastewater treatment facili-ty as described in 10 CSR 20-8.110(3).

B. The design peak hourly flows shallbe used to evaluate the effect of hydraulicpeaks on unit processes, pumping, piping,etc.

C. The design of treatment units thatare not subject to peak hourly flow require-ments shall be based on the design averageflow.

2. Organic design. Base organic loadingsfor wastewater treatment facility design on theinformation given in 10 CSR 20-8.110(3).When septage is accepted at a wastewatertreatment facility, the effects of septage flowshall be evaluated in the design.

(6) Outfalls.(A) Protection and Maintenance. The out-

fall shall be so constructed and protectedagainst the effects of flood water, ice, orother hazards as to reasonably ensure itsstructural stability and freedom from stop-page.

(B) Sampling Provisions. All samplingpoints shall be designed so that a representa-tive and discrete twenty-four (24) hour auto-matic composite sample or grab sample of theeffluent discharge can be obtained at a pointafter the final treatment process and beforedischarge to or mixing with the receivingwaters.

(C) All outfalls shall be posted with a per-manent sign indicating the outfall number(i.e., Outfall #001).

(7) Essential Facilities.(A) Emergency Power Facilities.

1. General. All wastewater treatmentfacilities shall be provided with an alternatesource of electric power or pumping capability


Secretary of State


to allow continuity of operation during powerfailures.

2. Power for disinfection. Disinfectionand dechlorination, when used, shall be pro-vided during all power outages.

(B) Electrical Controls. Electrical systemsand components in raw wastewater or inenclosed or partially enclosed spaces wherehazardous concentrations of flammable gasesor vapors that are normally present, shallcomply with the NFPA 70 National ElectricCode (NEC) (2017 Edition), as approved andpublished August 24, 2016, requirements forClass I, Division 1, Group D locations. Thisstandard shall hereby be incorporated by ref-erence in this rule, as published by NationalFire Protection Association® (NFPA), 1 Bat-terymarch Park, Quincy, MA 02169-7471.This rule does not incorporate any subse-quent amendments or additions.

(C) Alarm Systems. An audiovisual alarmor a more advanced alert system, with a self-contained power supply, capable of monitor-ing the condition of equipment whose failurecould result in a violation of the operatingpermit, shall be provided for all wastewatertreatment facilities.

(D) Water Supply.1. General. No piping or other connec-

tions shall exist in any part of the wastewatertreatment facility that might cause the con-tamination of a potable water supply.

2. Direct hot water connections. Hotwater for any direct connections shall not betaken directly from a boiler used for supply-ing hot water to a digester heating unit or heatexchanger.

3. Indirect connections.A. Where a potable water supply is to

be used for any purpose in a wastewater treat-ment facility other than direct connections, abreak tank, pressure pump, and pressuretank, or a reduced pressure backflow preven-ter consistent with the department’s PublicDrinking Water Branch shall be provided.

B. A sign shall be permanently postedat every hose bib, faucet, hydrant, or sill cocklocated on the water system beyond the breaktank or backflow preventer to indicate thatthe water is not safe for drinking.

4. Separate non-potable water supply.Where a separate non-potable water supply isto be provided, a break tank will not be nec-essary, but all system outlets shall be postedwith a permanent sign indicating the water isnot safe for drinking.

(E) Flow Measurement. A means of flowmeasurement shall be provided at all wastew-ater treatment facilities.

(F) Sampling Equipment. Effluent twenty-four (24) hour composite automatic samplingequipment shall be provided at all mechanical

wastewater treatment facilities and at otherfacilities where necessary under provisions ofthe operating permit. See 10 CSR 20-7.015.

(G) Housed Facilities. Where wastewatertreatment units are in a housed facility, followthe provisions in subsection (8)(J) of this rulefor ventilation.

(8) Safety. Adequate provisions shall be madeto effectively protect facility personnel andvisitors from hazards. The following shall beprovided to fulfill the particular needs of eachwastewater treatment facility:

(A) Fencing. Enclose the facility site witha fence designed to discourage the entrance ofunauthorized persons and animals;

(B) Gratings over appropriate areas oftreatment units where access for maintenanceis necessary;

(C) First aid equipment;(D) Posted “No Smoking” signs in haz-

ardous areas;(E) Appropriate personal protective equip-

ment (PPE);(F) Portable blower and hose sufficient to

ventilate accessed confined spaces;(G) Portable lighting equipment complying

with NEC requirements. See subsection(7)(B) of this rule;

(H) Gas detectors listed and labeled for usein NEC Class I, Division 1, Group D loca-tions. See subsection (7)(B) of this rule;

(I) Appropriately-placed warning signs forslippery areas, non-potable water fixtures(see subparagraph (7)(D)3.B. of this rule),low head clearance areas, open service man-holes, hazardous chemical storage areas,flammable fuel storage areas, high noiseareas, etc.;

(J) Ventilation. Ventilation shall include thefollowing:

1. Isolate all pumping stations andwastewater treatment components installed ina building where other equipment or officesare located from the rest of the building by anair-tight partition, provide separate outsideentrances, and provide separate and indepen-dent fresh air supply;

2. Force fresh air into enclosed screen-ing device areas or open pits more than fourfeet (4') deep. Also see 10 CSR 20-8.130(3)(F);

3. Dampers. Dampers are not to be usedon exhaust or fresh air ducts. Avoid the use offine screens or other obstructions on exhaustor fresh air ducts to prevent clogging;

4. Continuous ventilation. Where con-tinuous ventilation is needed (e.g., housedfacilities), provide at least twelve (12) com-plete air changes per hour. Where continuousventilation would cause excessive heat loss,provide intermittent ventilation of at least

thirty (30) complete air changes per hourwhen facility personnel enter the area. Baseair change demands on one hundred percent(100%) fresh air;

5. Electrical controls. Mark and conve-niently locate switches for operation of venti-lation equipment outside of the wet well orbuilding. Interconnect all intermittently oper-ated ventilation equipment with the respectivewet well, dry well, or building lighting sys-tem. The manual lighting/ventilation switchis expected to override the automatic con-trols. For a two (2) speed ventilation systemwith automatic switch over where gas detec-tion equipment is installed, increase the ven-tilation rate automatically in response to thedetection of hazardous concentrations ofgases or vapors; and

6. Fans, heating, and dehumidification.Fabricate the fan wheel from non-sparkingmaterial. Provide automatic heating anddehumidification equipment in all dry wellsand buildings. Follow the provisions in sub-section (7)(B) of this rule for electrical con-trols;

(K) Explosion-proof electrical equipment,non-sparking tools, gas detectors, and similardevices, in work areas where hazardous con-ditions may exist, such as digester vaults andother locations where potentially explosiveatmospheres of flammable gas or vapor withair may accumulate. See subsection (7)(B) ofthis rule;

(L) Provisions for local lockout/tagout onstop motor controls and other devices;

(M) Provisions for an arc flash hazardanalysis and determination of the flash pro-tection boundary distance and type of PPE toreduce exposure to major electrical hazardsin accordance with NFPA 70E Standard forElectrical Safety in the Workplace (2018 Edi-tion), as approved and published August 21,2017. This standard shall hereby be incorpo-rated by reference in this rule, as publishedby National Fire Protection Association®, 1Batterymarch Park, Quincy, MA 02169-7471. This rule does not incorporate any sub-sequent amendments or additions.

(9) Chemical Handling.(A) General.

1. Containment materials. The materialsutilized for storage, piping, valves, pumping,metering, and splash guards, etc., shall bespecially selected considering the physicaland chemical characteristics of each haz-ardous or corrosive chemical.

2. Secondary containment. Secondarycontainment storage areas contain the storedvolume until it can be safely transferred toalternate storage or released to the wastewa-ter treatment plant at controlled rates that will



not damage the facilities, inhibit the treatmentprocesses, or contribute to stream pollution.Secondary containment shall be designed asfollows:

A. A minimum volume of one hun-dred twenty-five percent (125%) of the vol-ume of the largest storage container locatedwithin the containment area plus the spaceoccupied by any other tanks located withinthe containment area when not protectedfrom precipitation;

B. A minimum volume of one hun-dred ten percent (110%) of the volume of thelargest storage container located within thecontainment area plus the space occupied byany other tanks located within the contain-ment area when protected from precipitation;and

C. Walls and floors of the secondarycontainment structure constructed of suitablematerial that is compatible with the specifica-tions of the product being stored.

3. Splash guards. All pumps or feedersfor hazardous or corrosive chemicals shallhave guards that will effectively prevent sprayof chemicals into space occupied by facilitypersonnel.

4. Piping, labeling, and coupling guardlocations.

A. All piping containing or transport-ing corrosive or hazardous chemicals shall beidentified with labels every ten feet (10') andwith at least two (2) labels in each room,closet, or pipe chase.

B. All connections (flanged or othertype), except those adjacent to storage orfeeder areas, shall have guards that will directany leakage away from space occupied byfacility personnel.

5. Alarm system. Facilities shall be pro-vided for automatic shutdown of pumps andsounding of alarms when failure occurs in apressurized chemical discharge line.

6. Dust. Dust collection equipment shallbe provided to protect facility personnel fromdusts injurious to the lungs or skin and to pre-vent polymer dust from settling on walkwaysthat become slick when wet.

(B) Chemical Housing. The following shallbe provided to fulfill the particular needs ofeach chemical housing facility:

1. Provide storage for a minimum ofthirty (30) days’ supply, unless local suppliersand conditions indicate that such storage canbe reduced without limiting the supply;

2. Construct the chemical storage roomof fire and corrosion resistant material;

3. Equip doors with panic hardware. Toprevent unauthorized access, doors lock butdo not need a key to exit the locked roomusing the panic hardware;

4. Provide chemical storage areas with

drains, sumps, finished water plumbing, andthe hose bibs and hoses necessary to clean upspills and to wash equipment;

5. Construct chemical storage areafloors and walls of material that is suitable tothe chemicals being stored and that is capableof being cleaned;

6. Install floor surfaces to be smooth,chemical resistant, slip resistant, and welldrained with three inches per ten feet (3"/10')minimum slope;

7. Provide adequate lighting;8. Comply with the NEC recommenda-

tion for lighting and electrical equipmentbased on the chemicals stored. See subsec-tion (7)(B) of this rule;

9. Store chemical containers in a cool,dry, and well-ventilated area;

10. Design vents from feeders, storagefacilities, and equipment exhaust to dischargeto the outside atmosphere above grade andremote from air intakes;

11. Locate storage area for chemicalcontainers out of direct sunlight;

12. Maintain storage temperatures inaccordance with relevant Material SafetyData Sheets (MSDS);

13. Control humidity as necessary whenstoring dry chemicals;

14. Design the storage area with desig-nated areas for “full” and “empty” chemicalcontainers;

15. Provide storage rooms housingflammable chemicals with an automaticsprinkler system designed for four tenths gal-lons per minute per square foot (0.4 gpm/ft2)and a minimum duration of twenty (20) min-utes;

16. Store incompatible chemicals sepa-rately to ensure the safety of facility person-nel and the wastewater treatment system.Store any two (2) chemicals that can react toform a toxic gas in separate housing facilities;

17. Design and isolate areas intended forstorage and handling of chlorine and sulfurdioxide and other hazardous gases. Followthe provisions in 10 CSR 20-8.190(3) and 10CSR 20-8.190(4) for chlorine and dechlori-nation;

18. Design an isolated fireproof storagearea and explosion proof electrical outlets,lights, and motors for all powdered activatedcarbon storage and handling areas in accor-dance with federal, state, and local require-ments;

19. Vent acid storage tanks to the outsideatmosphere, but not through vents in com-mon with day tanks;

20. Keep concentrated acid solutions ordry powder in closed, acid-resistant shippingcontainers or storage units; and

21. Pump concentrated liquid acids in

undiluted form from the original container tothe point of treatment or to a covered storagetank. Do not handle in open vessels.

(C) Chemical Handling Design. The fol-lowing shall be provided, where applicable,for the design of chemical handling:

1. Make provisions for measuring quan-tities of chemicals used for treatment or toprepare feed solutions over the range ofdesign application rates;

2. Select storage tanks, piping, andequipment for liquid chemicals specific to thechemicals;

3. Install all liquid chemical mixing andfeed installations on corrosion resistantpedestals;

4. Provide sufficient capacity of solutionstorage or day tanks feeding directly for twen-ty-four- (24-) hour operation at design aver-age flow;

5. Provide a minimum of two (2) chem-ical feeders for continuous operability. Pro-vide a standby unit or combination of units ofsufficient capacity to replace the largest unitout-of-service;

6. Chemical feeders shall—A. Be designed with chemical feed

equipment to meet the maximum dosagerequirements for the design average flow con-ditions;

B. Be able to supply, at all times, thenecessary amounts of chemicals at an accu-rate rate throughout the range of feed;

C. Provide proportioning of chemicalfeed to the rate of flow where the flow rate isnot constant;

D. Be designed to be readily accessi-ble for servicing, repair, and observation;

E. Protect the entire feeder systemagainst freezing;

F. Be located adjacent to points ofapplication to minimize length of feed lines;

G. Provide for both automatic andmanual operation for chemical feed controlsystems;

H. Utilize automatic chemical dose orresidual analyzers, and where provided,include alarms for critical values and record-ing charts;

I. Provide screens and valves on thechemical feed pump suction lines; and

J. Provide an air break or anti-siphondevice where the chemical solution enters thewater stream;

7. Dry chemical feed system shall—A. Be equipped with a dissolver capa-

ble of providing a minimum retention periodof five (5) minutes at the maximum feed rate;

B. Be equipped with two (2) solutionvessels and transfer piping for polyelectrolytefeed installations;

C. Have an eductor funnel or other


Secretary of State


appropriate arrangement for wetting the poly-mer during the preparation of the stock feedsolution on the makeup tanks;

D. Provide adequate mixing by meansof a large diameter, low-speed mixer;

E. Make provisions to measure thedry chemical volumetrically or gravimetrical-ly; and

F. Completely enclose chemicals andprevent emission of dust;

8. Provide for uniform strength of solu-tion consistent with the nature of the chemi-cal solution for solution tank dosing;

9. Use solution feed pumps to feedchemical slurries that are not diaphragm orpiston type positive displacement types;

10. Provide continuous agitation tomaintain slurries in suspension;

11. Provide a minimum of two (2) floc-culation tanks or channels having a combineddetention period of twenty to thirty (20 – 30)minutes. Provide independent controls foreach tank or channel;

12. Insulate pipelines carrying soda ashat concentrations greater than twenty percent(20%) solution to prevent crystallization; and

13. Prohibit bagging soda ash in a dampor humid place.

(D) Chemical Safety. The following shallbe provided in addition to the safety provi-sions in section (8) of this rule:

1. Appropriate personal protectiveequipment (PPE).

2. Eye wash fountains and safety show-ers. Eye wash fountains and safety showersutilizing potable water shall be provided inthe laboratory and on each level or worklocation involving hazardous or corrosivechemical storage, mixing (or slaking), pump-ing, metering, or transportation unloading.The design of eye wash fountains and safetyshowers shall include the following:

A. Eye wash fountains with water ofmoderate temperature, fifty degrees to ninetydegrees Fahrenheit (50°–90°F), suitable toprovide fifteen to thirty (15–30) minutes ofcontinuous irrigation of the eyes;

B. Emergency showers capable of dis-charging twenty gallons per minute (20 gpm)of water of moderate temperature, fiftydegrees to ninety degrees Fahrenheit (50°–90°F), and at pressures of thirty to fiftypounds per square inch (30–50 psi);

C. Eye wash fountains and emergencyshowers located no more than twenty-five feet(25') from points of hazardous chemicalexposure; and

D. Eye wash fountains and showersthat are to be fully operable during all weath-er conditions; and

3. Warning signs. Warning signs requir-ing use of goggles shall be located near

chemical stations, pumps, and other points offrequent hazard.

(E) Chemical Container Identification.The identification and hazard warning dataincluded on shipping containers, whenreceived, shall appear on all containers(regardless of size or type) used to store,carry, or use a hazardous substance.



10 CSR 20-8.150 Preliminary Treatment

PURPOSE: This rule specifies the minimumstandards for the design of preliminary treat-ment units that are part of wastewater collec-tion and treatment systems. This rule is to beused with rules 10 CSR 20-8.110 through 10CSR 20-8.210. It does not address all aspectsof design, and the design engineer may referto other appropriate reference materials solong as these minimum standards set forth inthis rule are met.

Editor’s Note: The secretary of state hasdetermined that the publication of this rule inits entirety would be unduly cumbersome orexpensive. The entire text of the material ref-erenced has been filed with the secretary ofstate. This material may be found at theOffice of the Secretary of State or at the head-quarters of the agency and is available to anyinterested person at a cost established bystate law.

(1) Applicability. Wastewater systems that uti-lize preliminary treatment shall be designedbased on criteria contained in this rule, pub-lished standards, applicable federal and staterequirements, standard textbooks, currenttechnical literature, and applicable safetystandards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) General. All wastewater treatment facili-ties must have a screening device, comminu-tor, or septic tank for the purpose of remov-ing debris and nuisance materials from theinfluent wastewater.

(3) Grease Interceptors. Grease interceptorsshall be provided on kitchen drain lines from

institutions, hospitals, hotels, restaurants,schools, bars, cafeterias, clubs, and otherestablishments from which relatively largeamounts of grease may be discharged to awastewater treatment facility owned by thegrease-producing entity. Grease interceptorsare typically constructed from fiberglass rein-forced polyester, high density polyethylene(HDPE), or concrete. For corrugated HDPEgrease interceptors, follow ASTM F2649 – 14Standard Specification for Corrugated HighDensity Polyethylene (HDPE) Grease Inter-ceptor Tanks, as approved and publishedSeptember 1, 2014. For precast concretegrease interceptor tanks, follow ASTM C1613– 17 Standard Specification for Precast Con-crete Grease Interceptor Tanks, as approvedand published September 1, 2017. Thesestandards shall hereby be incorporated by ref-erence into this rule, as published by ASTMInternational, 100 Barr Harbor Drive, POBox C700, West Conshohocken, PA 19428-2959. This rule does not incorporate any sub-sequent amendments or additions.

(4) Screening Devices.(A) General.

1. Freeze protection. All screeningdevices and screening storage areas shall beprotected from freezing.

2. Provisions shall be made for isolatingor removing screening devices from theirlocation for servicing.

3. Safety.A. Railings and gratings.

(I) Manually cleaned screen chan-nels shall be protected by guard railings anddeck gratings with adequate provisions forremoval or opening to facilitate raking.

(II) Mechanically cleaned screenchannels shall be protected by guard railingsand deck gratings. Give consideration to tem-porary access arrangements to facilitatemaintenance and repair.

B. Mechanical devices.(I) Mechanical screening equip-

ment shall have adequate removal enclosuresto protect facility personnel against accidentalcontact with moving parts and to preventdripping in multi-level installations.

(II) A positive means of locking outeach mechanical device shall be provided.

(III) An emergency stop buttonwith an automatic reverse function shall belocated in close proximity to the mechanicaldevice.

C. Electrical Equipment, Fixtures,and Controls. Electrical equipment, fixtures,and controls in screening area where haz-ardous gases may accumulate shall meet therequirements of the electrical code referencedin 10 CSR 20-8.140(7)(B).



(B) Screens. Where two (2) or moremechanically cleaned screens are used, thedesign shall provide for taking the largest unitout-of-service without sacrificing the capabil-ity to handle the average design flow. Whereonly one mechanically cleaned screen isused, it shall be sized to handle the designpeak instantaneous flow.

(5) Comminutors. Provisions for location andsafety shall be in accordance with screeningdevices, paragraph (4)(A)3. of this rule.

(6) Grit removal facilities are required forwastewater treatment facilities that—

(A) Utilize membrane bioreactors for sec-ondary treatment;

(B) Utilize anaerobic digestion; (C) Receive wastewater from combined

sewers; or(D) Receive wastewater from collection

systems that receive substantial amounts ofgrit.



10 CSR 20-8.160 Settling

PURPOSE: This rule specifies the minimumstandards for the design of settling operationsthat are part of wastewater collection andtreatment systems. This rule is to be used withrules 10 CSR 20-8.110 through 10 CSR 20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

Editor’s Note: The secretary of state has deter-mined that the publication of this rule in itsentirety would be unduly cumbersome orexpensive. The entire text of the material ref-erenced has been filed with the secretary ofstate. This material may be found at the Officeof the Secretary of State or at the headquartersof the agency and is available to any interest-ed person at a cost established by state law.

(1) Applicability. Wastewater systems that uti-lize settling shall be designed based on criteriacontained in this rule, published standards,applicable federal and state requirements,standard textbooks, current technical litera-ture, and applicable safety standards. In theevent of any conflict between the above crite-ria, the requirement in this rule shall prevail.



(2) General Considerations.(A) Number of Units. Multiple settling

units capable of independent operation aredesirable and shall be provided in all wastew-ater treatment facilities where design flowsexceed one hundred thousand (100,000) gal-lons per day (gpd). Wastewater treatmentfacilities without multiple settling units shallbe designed to include other provisions toassure continuity of treatment.

(B) Flow Distribution. Effective flow split-ting devices and control appurtenances (e.g.gates and splitter boxes) shall be provided topermit proper proportioning of flow andsolids loading to each settling unit, through-out the expected range of flows.

(3) Design.(A) Side Water Depth. The minimum side

water depth shall be as follows in Table 160-1 below:

(B) Surface Overflow Rates.1. Primary settling tanks. Calculate the

surface overflow rates for both design averageflow and design peak hourly flow from Table160-2 below. The larger area shall determinethe size of the settling tank.

2. Final settling tanks – attached growthbiological reactors. Surface overflow rates forsettling tanks following attached growth bio-logical reactors shall not exceed one thousandtwo hundred gallons per day per square foot(1,200 gpd/ft2) based on the design peakhourly flow.

3. Final settling tanks – activated sludge.The following design criteria in Table 160-3,

included herein, shall not be exceeded:

(C) Weirs.1. General. Overflow weirs shall be

readily adjustable over the life of the struc-ture to correct for differential settlement ofthe tank.

2. Design rates. The following weirloadings in Table 160-4, below, shall not beexceeded:

(D) Submerged Surfaces. The undersideand the tops of troughs, beams, and similarsubmerged construction elements shall have aminimum slope of one vertical to one hori-zontal (1:1) to prevent the accumulation ofscum and solids.

(E) Freeboard. Walls of settling tanks shallextend at least six inches (6") above the sur-rounding ground surface and shall providenot less than twelve inches (12") of free-board.

(4) Sludge Removal.(A) Settling floor. The minimum slope of

the settling floor shall be one vertical to


Secretary of State


twelve horizontal (1:12) for conventional set-tling tanks and one vertical to one hundredninety-two horizontal (1:192) for suctionstyle settling tanks.

(B) Sludge hopper. The minimum slope ofthe sludge hopper side walls shall be one andseven tenths vertical to one horizontal (1.7:1)(i.e., sixty degrees (60°) above the horizon-tal).

(C) When used, dual sludge hoppers shallprovide a minimum water depth of two feet(2') over the connecting wall that is betweenhoppers.

(5) Protective and Service Facilities.(A) Operator Protection. Safety features

shall appropriately include machinery covers,life lines, handrails on all stairways and walk-ways, and slip resistant surfaces. For addi-tional safety follow the provisions listed in 10CSR 20-8.140(8).

(B) Mechanical Maintenance Access. Thedesign shall provide for convenient and safeaccess to routine maintenance items such asgear boxes, scum removal mechanism, baf-fles, weirs, inlet stilling baffle areas, andeffluent channels.

(C) Electrical Equipment, Fixtures, andControls. For electrical equipment, fixtures,and controls in enclosed settling basins andscum tanks, where hazardous concentrationsof flammable gases or vapors may accumu-late, follow the provisions in 10 CSR 20-8.140(6)(B). The fixtures and controls shallbe conveniently located and safely accessiblefor operation and maintenance.



10 CSR 20-8.170 Solids Handling and Dis-posal

PURPOSE: This rule specifies the minimumstandards for the design of solids handlingand disposal operations that are part ofwastewater collection and treatment systems.This rule is to be used with rules 10 CSR 20-8.110 through 10 CSR 20-8.210. It does notaddress all aspects of design, and the designengineer may refer to other appropriate ref-erence materials so long as these minimumstandards set forth in this rule are met.

Editor’s Note: The secretary of state hasdetermined that the publication of this rule inits entirety would be unduly cumbersome or

expensive. The entire text of the material ref-erenced has been filed with the secretary ofstate. This material may be found at theOffice of the Secretary of State or at the head-quarters of the agency and is available to anyinterested person at a cost established bystate law.

(1) Applicability. Wastewater systems that uti-lize solids handling and disposal shall bedesigned based on criteria contained in thisrule, published standards, applicable federaland state requirements, standard textbooks,current technical literature, and applicablesafety standards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) General Design Considerations. Systemsto which this rule applies shall comply with10 CSR 20-8.140(7) and (8).

(3) Gravity Sludge Thickeners. For the mini-mum side water depth, follow the provisionslisted in Table 160-1 in 10 CSR 20-8.160(3)(A).

(4) Anaerobic Solids Digestion.(A) General.

1. Safety. Gas detectors shall be provid-ed for emergency use.

2. Alarm systems shall be provided inaccordance with 10 CSR 20-8.140(7)(C) towarn of:

A. Any drop of the liquid level belowminimum operating elevation; and

B. Low pressure in the space abovethe liquid level.

(B) High Level Emergency Overflow. Anunvalved vented overflow shall be provided toprevent damage to the digestion tank andcover in case of accidental overfilling. Pipethis emergency overflow back to the treat-ment process or side stream treatment facili-ty.

(C) Gas Collection, Piping, and Appurte-nances.

1. Safety equipment. Where gas is pro-duced, all necessary safety facilities shall:

A. Provide pressure and vacuumrelief valves and flame traps, together withautomatic safety shutoff valves and protectfrom freezing;

B. Not install water seal equipment;and

C. House gas safety equipment andgas compressors in a separate room with anexterior entrance.

2. Piping galleries shall be ventilated inaccordance with paragraph (4)(C)4. of thisrule.

3. Electrical fixtures, equipment, andcontrols. Electrical fixtures, equipment, andcontrols shall comply with the National Elec-trical Manufacturers Association (NEMA)4X enclosure rating where necessary; NEMAStandard 250-2014, published December 15,2014. This standard shall be incorporated byreference into this rule, as published byNational Electrical Manufacturers Associa-tion, 1300 North 17th Street, Arlington, VA22209. This rule does not incorporate anysubsequent amendments or additions. Electri-cal equipment, fixtures, and controls, inplaces enclosing and adjacent to anaerobicdigestive appurtenances where hazardousgases are included.

4. Ventilation. Any underground enclo-sures connecting with digestion tanks or con-taining solids or gas piping or equipmentshall be provided with forced ventilation inaccordance with 10 CSR 20-8.140(8)(J).

(D) Water Supply. Water supplies usingindirect connections shall comply with 10CSR 20-8.140(7)(D).

(5) Aerobic Solids Digestion High LevelEmergency Overflow. An unvalved emergen-cy overflow shall be provided that will conveydigester overflow to the treatment plant head-works, the aeration process, or to another liq-uid sludge storage facility and that has analarm for high level conditions.

(6) For solids pumping systems, audio-visualalarms shall be provided in accordance with10 CSR 20-8.140(7)(C) for:

(A) Pump failure;(B) Pressure loss; and(C) High pressure.

(7) Solids Dewatering.(A) Belt presses and conveyors shall be

provided with emergency shutoff controlsalong the entire length of the belt presses andconveyors that will—

1. Stop the press in an emergency; and2. Trigger an audible alarm.

(B) Alarm systems shall be provided tonotify the operator(s) of conditions that couldresult in process equipment failure or dam-age, threaten operator safety, or a solids spillor overflow condition.

(8) Sludge and Biosolids Storage Lagoons.The sludge lagoon bottoms and embankmentsshall be sealed in accordance with 10 CSR20-8.200(4)(C) to prevent leaching into adja-cent soils or groundwater.

AUTHORITY: section 644.026, RSMo 2016.*



Original rule filed Aug. 10, 1978, effectiveMarch 11, 1979. Amended: Filed June 15,2018, effective Feb. 28, 2019.


10 CSR 20-8.180 Biological Treatment

PURPOSE: This rule specifies the minimumstandards for the design of biological treat-ment that is part of wastewater collection andtreatment systems. This rule is to be used withrules 10 CSR 20-8.110 through 10 CSR 20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.


(1) Applicability. Wastewater systems that uti-lize biological treatment shall be designedbased on criteria contained in this rule, pub-lished standards, applicable federal and staterequirements, standard textbooks, currenttechnical literature, and applicable safetystandards. In the event of any conflictbetween the above criteria, the requirement inthis rule shall prevail.



(2) Septic Tanks.(A) A septic tank must have a minimum

capacity of at least one thousand (1,000) gal-lons.

(B) The septic tank shall be baffled.

(3) Recirculating Media Filters.(A) Location. Recirculating media filters

shall be located in accordance with the mini-mum separation distances at 10 CSR 20-8.140(2)(C)(2).

(B) Filter Bed. A minimum of two (2) fil-ter beds and a diversion box are required forall design flows.

(C) Dosing. Both timer and float switchcontrols are required; timers are the primarymethod of operation and the float switch con-trol is a back-up.

(D) Loading. Hydraulic loading rateshall—

1. Follow the manufacturer’s recom-mendation for synthetic media filters; and

2. Not exceed three and one-half gallonsper day per square foot (3.5 gpd/sqft) forsand or rock filters.

(E) Media Characteristics. The media isany of a number of physical structures whosesole purpose is to provide a surface to supportbiological growth. Commonly used mediaincludes rock, gravel, and sand of varioussizes, textile media, and peat. Finely crushedlimestone, dolomite, slag, any clay, lime-stone, or appreciable amounts of organicmaterial is not acceptable.

1. Rock, sand, and gravel media, whenused shall–

A. Be a total of at least thirty-threeinches (33”) deep; and

B. Have at least twenty-four inches(24”) of fine filtering media.

(4) Trickling Filters.(A) General. Trickling filters may be used

for treatment of wastewater amenable to treat-ment by aerobic biologic processes.

(B) Media.1. Media depth shall—

A. Be a minimum depth of five feet(5') above the underdrains for rock filtermedia;

B. Be a minimum depth of ten feet(10') for manufactured filter media to provideadequate contact time with the wastewater;and

C. Be no more than ten feet (10') forrock filter media.

2. Size and grading of rock and similarmedia shall—

A. Contain no more than five percent(5%) by weight of pieces whose longestdimension is three (3) times the least dimen-sion;

B. Be free from thin elongated andflat pieces, dust, clay, sand, or fine material;and

C. Conform to the following size andgrading as shown in Table 180-1, includedherein, when mechanically graded overvibrating screen with square openings.

3. Manufactured and synthetic mediamaterial shall—

A. Be used in accordance with allmanufacturer’s recommendations;

B. Be insoluble in wastewater andresistant to flaking, spalling, ultravioletdegradation, disintegration, erosion, aging,common acids and alkalis, organic com-pounds, and biological attack;

C. Be evaluated to determine the suit-ability based on experience with an installa-tion treating wastewater under similarhydraulic and organic loading conditions(include a relevant case history involving theuse of the synthetic media);

D. Have a structure able to supportthe synthetic media, water flowing through ortrapped in voids, and the maximum anticipat-ed thickness of the wetted biofilm;

E. Support the maintenance activities,unless a separate provision is made for main-tenance access to the entire top of the trick-ling filter media and to the distributor; and

F. Be placed with the edges matchedas nearly as possible to provide consistenthydraulic conditions within the trickling fil-ter.

(C) Underdrainage System. 1. Hydraulic capacity. The underdrains

shall be designed with— A. Slopes of at least one percent

(1%);B. Effluent channels that produce a

minimum velocity of two feet per second (2fps) at average daily rate of application to thefilter;

C. Underdrainage system, effluentchannels, and effluent pipe that permit freepassage of air;

D. Drains, channels, and pipe so thatnot more than fifty percent (50%) of theircross section area will be submerged underthe design peak hydraulic loading, includingproposed or possible future or recirculatedflows.

(D) Forced Ventilation.1. Forced ventilation for a trickling fil-

ter is required when—A. Designed for nitrification;B. Designed with a media depth in

excess of six feet (6’); orC. Designed where seasonal or diur-

nal temperatures do not provide sufficientdifference between the ambient air andwastewater temperatures to sustain passiveventilation.

2. Minimum design airflow rate to nitri-fy using a trickling filter shall be the greaterof—

A. Fifty pounds (50 lbs) of oxygenprovided per pound of oxygen demand ataverage organic loading, based on stoichiom-etry; or

B. Thirty pounds (30 lbs) of oxygen


Secretary of State


provided per pound of oxygen demand atpeak organic loading, based on stoichiome-try.

(5) Activated Sludge.(A) Basin lining. If using a synthetic liner,

it shall be a minimum of thirty millimeters(30 mm) thick.

(B) Tank dimensions. Horizontally mixedaeration tanks shall have a depth of not lessthan five and a half feet (5.5').

(C) High purity oxygen, when used andenclosed. An enclosed high purity oxygenexhaust system shall be provided to collectand vent the reactor off-gases.

(6) Sequencing Batch Reactor (SBR).(A) General. The minimum total basin vol-

ume shall be equal to the design daily influ-ent flow volume and either upstream in-lineor off-line storage is necessary to minimizeinfluent flow during settling and decanting.

(B) Design. A minimum of two (2) reactorbasins shall be installed.

(7) Membrane Bioreactor (MBR).(A) General.

1. For wastewater treatment plants witha flow equal to or greater than one hundredthousand gallons per day (100,000 gpd), theMBR process must be designed with a mini-mum of two (2) membrane trains capable oftreating the daily average flow with one (1)membrane cassette out of service.

2. Design flux criteria must be satisfiedwith one (1) membrane module out-of-ser-vice (e.g., for external clean in place, recov-ery cleaning, repair). For purposes of thesecriteria, a membrane module is the smallestmembrane unit capable of separate removalfrom the tank while maintaining operation ofother membrane units in the same tank.

3. Membranes placed in the aerationbasin(s) rather than a separate membranetank shall have—

A. Individual modules and individualdiffusers that can be removed separately formaintenance and repair; and

B. Aeration basin(s) volume sized forcomplete nitrification.

(B) Preliminary Treatment. Each systemshall—

1. Be consistent with the membranemanufacturer recommendations;

2. Comply with 10 CSR 20-8.150(6) forgrit removal;

3. Provide oil and grease removal whenthe levels in the influent may cause damage tothe membranes;

4. Provide a fine screen and high wateralarm, designed to treat peak hourly flow.Coarse screens followed by fine screens may

be used in larger facilities to minimize thecomplications of fine screening; and

5. Comply with 10 CSR 20-8.150(4)(B)for reliability.

(C) Aeration. The aeration blowers mustprovide adequate air for membrane scour andprocess demands.

(D) Redundancy. The facility shall have atleast one (1) of the following:

1. The ability to run in full pro-grammable logic control (PLC) or standbypower mode in case of an automatic controlfailure;

2. An operational battery backup PLC ifmanual control is not possible; or

3. Sufficient standby power generatingcapabilities to provide continuous flowthrough the membranes during a power outage(e.g., preliminary screening, process aeration,recycle/RAS/permeate pumps, air scour, vacu-um pumps) or an adequate method to handleflow for an indefinite period (e.g., privatecontrol of influent combined with contingen-cy methods).

(E) Operations and Maintenance. TheMBR design shall—

1. Include provisions to monitor mem-brane integrity;

2. Provide on-line continuous turbiditymonitoring of filtrate or an equivalent foroperational control and indirect membraneintegrity monitoring for a treatment plantwith design average flow greater than orequal to one hundred thousand gallons perday (100,000 gpd); and

3. Include provisions to remove mem-brane cassette for cleaning considering themembrane cassette wet weight plus addition-al weight of the solids accumulated on themembranes.

(8) Moving Bed Bioreactor (MBBR). AMBBR secondary treatment system shall pro-vide upstream preliminary treatment unitscapable of—

(A) Screening to reduce pass-through andsuspended solids;

(B) Grit removal; and(C) Oil and grease removal.



10 CSR 20-8.190 Disinfection

PURPOSE: This rule specifies the minimumstandards for the design of disinfection pro-cesses that are part of wastewater collectionand treatment systems. This rule is to be usedwith rules 10 CSR 20-8.110 through 10 CSR20-8.210. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.

(1) Applicability. Wastewater systems that uti-lize disinfection shall be designed based oncriteria contained in this rule, published stan-dards, applicable federal and state require-ments, standard textbooks, current technicalliterature, and applicable safety standards. Inthe event of any conflict between the abovecriteria, the requirement in this rule shall pre-vail.



(2) General.(A) Emergency Power. Disinfection and

dechlorination processes, when used, shall beprovided during all power outages. For addi-tional emergency power requirements, referto the provisions listed in 10 CSR 20-8.140(7).

(B) Secondary containment. Secondarycontainment shall comply with the provisionslisted in 10 CSR 20-8.140(9)(A)2.

(3) Chlorine Disinfection.(A) Contact period. A minimum contact

period of fifteen (15) minutes at design peakhourly flow or maximum rate of pumpageshall be provided after thorough mixing.

(B) Gaseous Chlorine Housing. 1. Feed and storage rooms shall—

A. Have chlorine gas feed and storagerooms constructed of fire and corrosion resis-tant material;

B. Provide a gas-tight room to sepa-rate equipment from any other portion of thebuilding if gas chlorination equipment orchlorine cylinders are to be in a building usedfor other purposes;

C. Have smooth floor surfaces thatare chemical resistant, impervious, and slipresistant. Floor drains are discouraged.Design floor drains, where provided, with theability to be plugged and sealed;

D. Have doors to this room that onlyopen to the outside of the building, and areequipped with panic hardware. Provide doorlocks to prevent unauthorized access, but do



not need a key to exit the locked room usingthe panic hardware;

E. Be well-lit with lights that aresealed so that they will continue working dur-ing a chlorine leak. Comply with 10 CSR 20-8.140(7)(B), requirements for Class I, Divi-sion 2, Group D locations when selectinglighting and electrical equipment;

F. Be at ground level and permit easyaccess to all equipment;

G. Separate storage areas for one- (1-)ton cylinders from the feed area; and

H. Have designated areas for “full”and “empty” cylinder storage.

2. Heating and cooling.A. Rooms containing disinfection

equipment shall be provided with a means ofheating and cooling so that a temperature ofat least sixty degrees Fahrenheit (60° F) andno more than eighty-six degrees Fahrenheit(86°F) can be maintained.

B. Heating or air conditioning equip-ment provided for the chlorinator room shallbe separate from central heating and air con-ditioning systems to prevent chlorine gasfrom entering the central system and centralheating or cooling ducts are not allowed toterminate or pass through a chlorinator room.

3. Ventilation shall conform to the fol-lowing:

A. Install forced mechanical ventila-tion to provide one (1) complete fresh airchange per minute when the chlorinator roomis occupied. Construct fans of chemical resis-tant materials and have chemical proofmotors. Squirrel cage type fans located out-side the chlorinator room may be approved ifthe fan housings and ducting are airtight andmade of chlorine and corrosion resistantmaterial;

B. Locate the entrance to the airexhaust duct from the room no more thantwelve inches (12") off the floor. Locate thepoint of discharge as not to contaminate theair inlet to any buildings or present a hazardat the access to the chlorinator room or otherinhabited areas. Utilize louvers for airexhaust to facilitate airtight closure;

C. Locate air inlets as to providecross ventilation. Place the outside air inlet atleast three feet (3') above grade. Utilize lou-vers for air inlets to facilitate airtight closure;and

D. Position the vent hose from thechlorinator to the outside atmosphere abovegrade. Provide passive vent screens.

4. Electrical controls. Switches for fansand lights shall be outside of the chlorinatorroom at the entrance.

5. Protective and respiratory gear.Where chlorine gas is present the applicantshall comply with 10 CSR 20-8.140(9)(D)1.

(C) Alarm System. The applicant shallconform to 10 CSR 20-8.140(7)(C) and beresponsible for specifying what the alarmrequirements are necessary to assure consis-tent disinfection in compliance with theapplicable bacteria limits and the disinfectionresidual limit in the effluent.

(D) Sampling Equipment. Sampling equip-ment shall be consistent with the require-ments in 10 CSR 20-8.140(7)(F).

(4) Dechlorination.(A) Containers. Dilution tanks and mixing

tanks are required when using dry com-pounds and may be necessary when using liq-uid compounds to deliver the proper dosage.

(B) Mixing and Contact Requirements.1. Mixing requirements. Solid dechlori-

nation systems shall not be located in thechlorine contact tank.

2. Contact time. A minimum of thirty(30) seconds for mixing and contact timeshall be provided at the design peak hourlyflow or maximum rate of pumpage.

(C) Housing Requirements.1. Feed and storage rooms. The require-

ments for housing sulfite gas equipment shallfollow the same guidelines as for chlorinegas. For specific details follow the provisionslisted in subsection (3)(B).

2. Protective and respiratory gear. Seeparagraph (3)(B)5. of this rule.

(D) Alarm System. See subsection (3)(C)of this rule.

(E) Sampling Equipment. Sampling equip-ment shall be consistent with the require-ments in 10 CSR 20-8.140(7)(F).

(5) Ultraviolet Disinfection.(A) Dosage and System Sizing.

1. General. The UV dosage shall bebased on the design peak hourly flow, maxi-mum rate of pumpage, or peak batch flow.

2. Batch discharges. If no flow equaliza-tion is provided for a batch discharger, thedosage shall be based on the peak batch flow.

3. Bioassay. The UV system shall deliv-er the target dosage based on equipment der-ating factors and, if needed, have the UVequipment manufacturer verify that the scaleup or scale down factor utilized in the designis appropriate for the specific applicationunder consideration.

4. The design delivered UV dosage for awastewater treatment facility shall be a mini-mum of thirty thousand microwatt secondsper centimeters squared (30,000 μW • s/cm2)based on MS-2 phage inactivation.

(B) Design.1. Open channel systems. The combina-

tion of the total number of banks shall becapable of treating the design peak hourly

flow, maximum rate of pumpage, or peakbatch flow.

2. Closed vessel systems. The combina-tion of the total number of closed vesselsshall be capable of treating the design peakhourly flow, maximum rate of pumpage, orpeak batch flow.

3. Cleaning. Closed vessel systems uti-lizing medium-pressure lamps shall be pro-vided with an automatic cleaning system inorder to prevent algae growth.

(C) Monitoring and Alarms.1. The UV system must continuously

monitor and display at the UV system controlpanel the following minimum conditions:

A. The relative intensity of each bankor closed vessel system;

B. The operational status and condi-tion of each bank or closed vessel system;

C. The ON/OFF status of each lampin the system; and

D. The total number of operatinghours of each bank or each closed vessel sys-tem.

2. The UV system shall include analarm system. Alarm systems shall complywith 10 CSR 20-8.140(7)(C).

(D) Electrical Controls. For electrical con-trols, follow the provisions listed in 10 CSR20-8.140(7)(B) for electrical controlsrequirements.

(E) Sampling Equipment. Sampling equip-ment shall be consistent with the require-ments in 10 CSR 20-8.140(7)(F).



10 CSR 20-8.200 Wastewater TreatmentLagoons and Wastewater Irrigation Alter-natives

PURPOSE: This rule specifies the minimumstandards for the design of lagoons andwastewater irrigation alternatives that arepart of wastewater collection and treatmentsystems. This rule is to be used with rules 10CSR 20-8.110 through 10 CSR 20-8.210. Itdoes not address all aspects of design, and thedesign engineer may refer to other appropriatereference materials so long as these minimumstandards set forth in this rule are met.

PUBLISHER’S NOTE: The secretary of statehas determined that the publication of theentire text of the material which is incorpo-rated by reference as a portion of this rule


Secretary of State


would be unduly cumbersome or expen-sive. This material as incorporated by refer-ence in this rule shall be maintained by theagency at its headquarters and shall be madeavailable to the public for inspection andcopying at no more than the actual cost ofreproduction. This note applies only to thereference material. The entire text of the ruleis printed here.

(1) Applicability. Wastewater systems that uti-lize lagoons and wastewater irrigation alter-natives shall be designed based on criteriacontained in this rule, published standards,applicable federal and state requirements,standard textbooks, current technical litera-ture, and applicable safety standards. In theevent of any conflict between the above crite-ria, the requirement in this rule shall prevail.



(2) Supplementary Field Data for the FacilityPlan. The facility plan shall contain pertinentinformation on location, geology, soil condi-tions, area for expansion, and any other fac-tors that will affect the feasibility and accept-ability of the proposed project, including theinformation required per 10 CSR 20-8.110.The following information must be submit-ted:

(A) Lagoons and spray irrigation fieldsshall be located where stormwater runofffrom the watershed is minimized.

(B) Geohydrological Evaluation. A geohy-drological evaluation shall be requested on allnew earthen basins, earthen basin majormodifications, new wastewater irrigationsites, and subsurface absorption fields.

1. Severe Collapse Potential. Earthenbasins shall not be located in areas with asevere collapse potential rating.

(C) Soils investigation. Detailed soilsinvestigations and reports shall be submittedfor facilities surface irrigating more thantwenty-four inches per year (24”/ yr) and forall subsurface absorption fields. Soils reportsshall comply with 10 CSR 20-8.110(7).

(D) Where geosynthetic liners are used instorage or treatment basins for wastewaters ofan industrial nature, the application shall:

1. Document that the liner or storagestructure material is capable of containing thewastewater for at least twenty (20) years;

2. Specify repair or replacement proce-dures in the event of leakage or damage to theseal; and

3. Include an evaluation of secondarycontainment or leakage detection and collec-tion devices for corrosive or reactive wastew-

aters and for toxic materials.

(3) Basis of Design.(A) Area and Loadings for Discharging

Lagoons.1. Lagoon design for BOD5 loadings

shall not exceed thirty-four pounds per dayper acre (34 lbs/day/acre) at the three-foot(3') operating depth in the primary cells.

2. Aerated Lagoons. Aeration equipmentshall be capable of:

A. Maintaining the design level ofdissolved oxygen within a particular cell withone (1) unit in the cell out of service;

B. Maintaining a minimum dissolvedoxygen level of two milligrams per liter (2mg/L) in the lagoon at all times;

C. Delivering one and four tenthspounds of oxygen per pound of biochemicaloxygen demand removed (1.4 lbs O2/1 lbBOD); and

D. Delivering an additional four andsixth tenths pounds of oxygen per pound ofammonia nitrogen removal (4.6 lbs O2/1 lbNH3).

(B) Area and Loadings for Wastewater Irri-gation Storage Basins. Treatment prior to sur-face irrigation shall provide performanceequivalent to that obtained from a primarywastewater lagoon cell designed and con-structed in accordance with section (4) of thisrule, except that the lagoon depth may beincreased to include wastewater storage inaddition to the primary volume.

(4) Lagoon Construction Details.(A) Embankments and Berms.

1. Berms shall be constructed of rela-tively impervious material and compacted toat least ninety-five percent (95%) maximumdry density test method to form a stablestructure.

2. The minimum berm width shall beeight feet (8') to permit access of mainte-nance vehicles.

3. Minimum freeboard shall be two feet(2').

4. An emergency spillway shall be pro-vided that—

A. Prevents the overtopping and cut-ting of berms;

B. Is compacted and vegetated or oth-erwise constructed to prevent erosion; and

C. Has the ability for a representativesample to be collected, if discharging.

(B) Lagoon Bottom. Soil shall be compact-ed with the moisture content between twopercent (2%) below and four percent (4%)above the optimum water content and com-pacted to at least ninety-five percent (95%)maximum dry density test method.

(C) Lagoon Seal.

1. The lagoon shall be sealed to ensurethat seepage loss is as low as possible and hasa design permeability not exceeding 1.0 x 10-7 cm/sec.

2. Soil Seals. The minimum thickness ofthe compacted clay liner must be twelve inch-es (12"). For permeability coefficientsgreater than 1.0 × 10-7 cm/sec or for headsover five feet (5') such as an aerated lagoonsystem, the following formula shall be used todetermine minimum seal thickness, Equation200-1:Equation 200-1

H × Kt = ______________________

5.4 × 10-7 cm/sec

where:K = the permeability coefficient of the soil inquestion;H = the head of water in the lagoon; andt = the thickness of the soil seal.

3. Synthetic Liners. Synthetic sealsthickness may vary due to liner material, butthe liner thickness shall be no less than two-hundredths inch (.02") or twenty (20) mil andbe the appropriate material to perform underexisting conditions.

4. Seep collars shall be provided ondrainpipes where they pass through thelagoon seal.

(D) Influent Lines.1. Unlined corrugated metal pipe shall

not be used due to corrosion problems. 2. A manhole shall be installed with its

invert at least six inches (6") above the max-imum operating level of the lagoon, prior tothe entrance into the primary cell, and pro-vide sufficient hydraulic head without sur-charging the manhole. For manhole installa-tion, follow the provisions listed in 10 CSR8.120(4).

3. The influent line(s) shall be locatedalong the bottom of the lagoon so that the topof the pipe is just below the average elevationof the lagoon seal; however, there shall be anadequate seal below the pipe.

(5) Covers for Lagoon Retrofits.(A) Lagoon covers shall be constructed

with a minimum thickness of 2 mil or meetthe manufacturer’s recommendations, and beultraviolet and weather resistant.

(B) Trial seams shall be used to verifyacceptable installation techniques.

(C) The cover shall include a stormwaterremoval system that conveys collected precip-itation to sumps or includes drainage areas inthe membrane within the acceptable leakagerate to allow stormwater to drain into thelagoon.



(6) Surface Irrigation of Wastewater.(A) Site Considerations. For site consider-

ations, follow the provision in section (2) ofthis rule.

(B) Wetted Application Area. The wettedapplication area is the land area that is nor-mally wetted by wastewater application. Thewetted application area must be:

1. Located outside of flood-prone areashaving a flood frequency greater than onceevery ten (10) years;

2. Established—A. At least one hundred fifty feet

(150') from existing dwellings or public useareas, excluding roads or highways;

B. At least fifty feet (50') inside theproperty line;

C. At least three hundred feet (300')from any sinkhole, losing stream, or otherstructure or physiographic feature that mayprovide direct connection between the groundwater table and the surface;

D. At least three hundred feet (300')from any existing potable water supply wellnot located on the property. Adequate protec-tion shall be provided for wells located on theapplication site;

E. One hundred feet (100') to wet-lands, ponds, gaining streams (classified orunclassified; perennial or intermittent); and

F. If an established vegetated bufferor the wastewater is disinfected, the setbacksestablished in subsections (A)–(E) above maybe decreased if the applicant demonstrates therisk is mitigated.

3. Fenced, or if not fenced, provide inthe construction permit application or thefacility plan, the—

A. Method of disinfection being uti-lized;

B. Suitable barriers in place, orC. Details on how public access is

limited and not expected to be present. (C) Preapplication Treatment. At a mini-

mum, treatment prior to irrigation shall pro-vide performance equivalent to that obtainedfrom a primary wastewater lagoon celldesigned and constructed in accordance withsections (3) and (4) of this rule, except thatthe lagoon depth may be increased to includewastewater storage in addition to the primaryvolume.

1. The size of storage basins shall bebased on the design wastewater flows and netrainfall minus evaporation expected for a one(1) in ten (10) year twenty-four (24) hourreturn frequency for the storage period select-ed and shall meet the minimum storage dayslisted below.

A. Seventy-five (75) days for facilitieslocated in Scott, Stoddard, Butler, Dunklin,New Madrid, Pemiscot, Mississippi,

McDonald, Newton, Jasper, Lawrence,Barry, Stone, Taney, Christian, Green, Web-ster, Douglas, Ozark, Howell, Texas, Dent,Shannon, Oregon, Ripley, Carter, Reynolds,Iron, Madison, Wayne, Cape Girardeau, Bar-ton, Dade, Perry, and Bollinger counties.

B. Ninety (90) days for facilities locat-ed in Vernon, Bates, Henry, St. Clair, Cedar,Dallas, Polk, Hickory, Benton, Cooper, Mor-gan, Moniteau, Miller, Cole, Camden,Laclede, Pulaski, Phelps, Maries, Osage,Gasconade, Franklin, Jefferson, St. Louis,Ste. Genevieve, St. Francois, St. Charles,and Crawford counties.

C. One hundred five (105) days forfacilities located in Cass, Johnson, Pettis,Platte, Jackson, Clay, Ray, Lafayette, Carroll,Saline, Chariton, Randolph, Howard, Boone,Callaway, Audrain, Monroe, Ralls, Pike, Lin-coln, Warren, and Montgomery counties.

D. One hundred twenty (120) days forfacilities located in Atchison, Holt, Andrew,Nodaway, Worth, Gentry, DeKalb, Harrison,Daviess, Grundy, Mercer, Putnam, Sullivan,Linn, Macon, Adair, Schuyler, Scotland,Clark, Knox, Lewis, Shelby, Buchanan, Clin-ton, Caldwell, Livingston, and Marion coun-ties.

E. Seasonal facilities. For facilitiesthat operate and generate flows only fromApril through October season, a minimumstorage capacity of forty-five (45) days shallbe provided. For facilities that operate orgenerate flows only from November throughMarch, the minimum storage listed in sub-section (A)–(D) above is required.

(D) Application Rates and Soils Informa-tion. The application rates for each individu-al site shall be based on topography, soils,geology, hydrology, weather, agriculturalpractice, adjacent land use, and applicationmethod. Application of wastewater shall notbe allowed during periods of ground frost,frozen soil, saturated conditions, or precipita-tion events. In design of the application rates,the following shall apply:

1. Do not exceed the hourly applicationrate at the design sustained permeability rateexcept for short periods when initial soilmoisture is significantly below field capacity.Do not exceed an hourly rate of one-half (½)the design sustained permeability for slopesexceeding ten percent (10%).

2. Base the daily and weekly applicationrates on soil moisture holding capacity,antecedent rainfall, and depth to the mostrestrictive soil permeability.

A. For facilities applying at twenty-four inches per year (24"/yr), the applicationrate cannot exceed one inch (1") per day andthree inches (3") per week.

B. For facilities applying above twen-

ty-four inches per year (24"/yr), the applica-tion rate cannot exceed the values determinedin the soils report and loading design. Followthe provisions in 10 CSR 20-8.110(7), SoilsReports for additional information.

3. Design the maximum annual applica-tion rate not to exceed ten percent (10%) ofthe design sustained soil permeability rate forthe number of days per year when soils arenot frozen.

(E) The applicant shall defer the grazing ofanimals or harvesting of forage crops, as list-ed below, following wastewater irrigation,depending upon ambient air temperature andsunlight conditions.

1. Fourteen (14) days from grazing orforage harvesting during the period from May1 to October 31 of each year; and

2. Thirty (30) days from grazing or for-age harvesting during the period fromNovember 1 to April 30 of each year.

(F) Public Access Areas. Wastewater shallbe disinfected prior to irrigation (not storage)in accordance with 10 CSR 20-8.190.

1. The wastewater shall contain as fewof the indicator organisms as possible and inno case contain more than one hundred twen-ty-six (126) Escherichia coliform colonyforming units per one hundred milliliters(126 cfu/ 100 ml);

2. The public shall not be allowed intoan area when irrigation is being conducted;and

3. For golf courses utilizing wastewater,all piping and sprinklers associated with thedistribution or transmission of wastewatershall be color-coded and labeled or tagged towarn against the consumptive use of contents.

(G) Alarm System. An automatic notifica-tion alarm system shall be installed on thepressure monitoring system, on each pivotand pump system, and be capable of notify-ing an on-call operator when a fault occurs inthe system.

(7) Subsurface Absorption Systems.(A) Site Restrictions.

1. Subsurface systems shall—A. Exclude unstabilized fill and soils

that have been highly compacted and/or dis-turbed, such as old road beds, foundations, orsimilar things;

B. Provide adequate surface drainagewhere slopes are less than two percent (2%);

C. Provide surface and subsurfacewater diversion where necessary, such as acurtain or perimeter drain; and

D. Have a ten foot (10') buffer fromthe property line.

2. The vertical separation between thebottom of the drip lines and/or the trench anda limiting layer, including but not limited to,


Secretary of State


bedrock; restrictive horizon; or seasonal highwater table, shall be no less than:

A. Twenty-four inches (24"); or B. Twelve inches (12") for systems

dispersing secondary or higher quality efflu-ent; or

C. Forty-eight inches (48") wherekarst features are present unless the site canbe reclassified.

(B) Preliminary treatment. Subsurface sys-tems shall be, at a minimum, preceded bypreliminary treatment. For design of a sec-ondary treatment system, follow the provi-sions in 10 CSR 20-8.180 or section (3) ofthis rule.

(C) Loading rates shall not exceed the val-ues assigned by the site and soil evaluation.

(8) Low Pressure Pipe (LPP) Subsurface Sys-tems.

(A) Design.1. The LPP system shall be sized in

accordance with the following equations,Equation 200-2 and Equation 200-3: Equation 200-2

QA = ______

LTAR

andEquation 200-3

AL = ______

5 ftwhere:

A = Minimum LPP soil treatment area(square feet (sq.ft))

L = Minimum total length of LPP trench(ft)

Q = Maximum daily wastewater flow (gal-lons per day (gpd))

LTAR = Long term acceptance rate(gpd/sq.ft). This is the lowest reported LPPsoil loading rate between the soil surface andat least twelve inches (12") below the speci-fied LPP trench bottom, or as approved bythe Missouri Department of NaturalResources (department).

2. All network piping and low pressuredistribution piping and fittings with polyvinylchloride (PVC) shall meet ASTM Standard D1785 Standard Specification for Poly(VinylChloride) (PVC) Plastic Pipe, Schedules 40,80, or 120 as approved and published August1, 2015, or equivalent rated to meet orexceed ASTM D2466 Standard Specificationfor Poly(Vinyl Chloride) (PVC) Plastic Drain,Waste, and Vent Pipe and Fittings asapproved and published August 1, 2017.These standards shall hereby be incorporatedby reference into this rule, as published byASTM International, 100 Barr Harbor Drive,

PO Box C700, West Conshohocken, PA19428-2959. This rule does not incorporateany subsequent amendments or additions.

3. Manifold design shall address freezeprotection while assuring uniform distribu-tion and to minimize drain down of lateralsinto other laterals at a lower elevationbetween dosing events.

(B) Dosage. The dosing frequency shall bebased on the soils report and the dosing vol-ume in zoned systems.

(C) Orifices and Orifice Shielding.1. The orifice number and spacing shall

be designed to provide a distribution of nomore than six square feet per orifice with anorifice size of not less than one-eighth inch.

2. The distal pressure shall be designedand maintained at the end of each lateral to beno less than two feet (2 ft) (0.87 psi) whenusing three-sixteenth inch (3/16") or largerdiameter orifices, and no less than five feet (5ft) (2.18 psi) when using orifices smaller thanthree-sixteenth inch (3/16").

(9) Drip Dispersal Subsurface Systems.(A) Design.

1. The location and size of the drainsand buffers must be factored into the totalarea required for the drip dispersal system.

2. The drip dispersal system shall besized with the minimum soil treatment areaand total length, in accordance with the fol-lowing equations, Equation 200-4 and Equa-tion 200-5:Equation 200-4

QA = ______

HLREquation 200-5

AL = ______

2 feetWhere:

A = Minimum soil treatment area (squarefeet (sq. ft))

Q = Maximum daily wastewater flow (gal-lons per day (gpd))

HLR= Maximum hydraulic loading ratedetermined in the soils report (gpd/sq.ft)

L = Minimum total length (ft)(B) Lines.

1. The drip dispersal lines shall beplaced at a minimum depth of six inches (6")below the surface.

2. Emitters and drip dispersal lines shallbe placed at a minimum on a two foot (2')spacing to achieve even distribution of thewastewater and maximum utilization of thesoil.

AUTHORITY: section 644.026, RSMo 2016.*Original rule filed Aug. 10, 1978, effective

March 11, 1979. Amended: Filed June 15,2018, effective Feb. 28, 2019.


10 CSR 20-8.210 Supplemental Treatment

PURPOSE: This rule specifies the minimumstandards for the design of supplementaltreatment processes that are part of wastewa-ter collection and treatment systems. Thisrule is to be used with rules 10 CSR 20-8.110through 10 CSR 20-8.210. It does not addressall aspects of design, and the design engineermay refer to other appropriate referencematerials so long as these minimum stan-dards set forth in this rule are met.


(1) Applicability. Wastewater systems that uti-lize supplemental treatment shall be designedbased on criteria contained in this rule, pub-lished standards, applicable federal and staterequirements, standard textbooks, currenttechnical literature and applicable safety stan-dards. In the event of any conflict between theabove criteria, the requirement in this ruleshall prevail.



(2) Polishing Reactors.(A) Design. The process shall—

1. Provide a minimum hydraulic reten-tion time of three (3) hours;

2. Be based on actual reactor influentcharacteristics;

3. Be based on Biochemical OxygenDemand loading rate of forty-eight poundsper one thousand cubic feet per day (48 lbsBOD/1,000 cf/day) or less;

4. Be sized using less than two tenths apound TKN per one thousand square feet perday (0.2 lbs TKN/1,000 ft2/day) when nitri-fying;

5. Provide sufficient alkalinity with aminimum residual of fifty milligrams per liter(50 mg/L) in the effluent or include chemicaltreatment;

6. Include cold weather provisions, such



as heaters, insulated covers, installation oftemperature controlled enclosures for above-ground components to prevent freezing and toensure ammonia removal; and

7. Provide a blower malfunction alarmable to notify the operator of alarm activa-tions through audio-visual means.

(3) Filtration. (A) Filtration systems shall be preceded

with additional process, such as chemicalcoagulation and sedimentation or otheracceptable process, when:

1. Permit requirements for total sus-pended solids (TSS) are less than ten mil-ligrams per liter (10 mg/L);

2. Effluent quality is expected to fluctu-ate significantly;

3. Significant amounts of algae are pre-sent; or

4. The manufacturer recommends anadditional process.

(B) General Design. 1. Filtration systems shall have:

A. Convenient access to all compo-nents and the media surface for inspectionand maintenance without taking other unitsout of service;

B. Enclosed controls and heating andventilation equipment to control humidity;and

C. The capacity to process the designaverage flow to the filters with the largest unitout of service utilizing a minimum of two (2)units.

2. Flocculation. For filtration systemsrequiring coagulation and flocculation priorto the filtration, the flocculation system shall:

A. Include chemical feed equipmentto meet the system’s anticipated peak designflow and the ability to proportion chemicalfeed rates; and

B. Ensure the rapid dispersion andmixing of chemicals throughout the wastewa-ter by providing mechanical or in-line staticmixers.

(C) Deep bed filters. 1. The design of manifold type filtrate

collection or underdrain systems shall:A. Minimize loss of head in the man-

ifold and baffles;B. Provide the ratio of the area of the

underdrain orifices to the entire surface areaof the filter media at about three one-thou-sandths (0.003);

C. Provide the total cross-sectionalarea of the laterals at about twice the area ofthe final openings; and

D. Provide a manifold that has a min-imum cross sectional area that is one and onehalf (1.5) times the total area of the laterals.

2. All rotary surface wash devices shall

provide adequate surface wash water to pro-vide one half to one gallon per minute persquare foot (0.5-1.0 gpm/ sq ft) of filter area.

(D) Shallow bed filters. The shallow bedfilter shall:

1. Comply with the manufacturer’s rec-ommendations at average design flow;

2. Provide multiple unit operations toallow for continuous operability and opera-tional variability;

3. Consist of a series of up to eight inch(8") filter increments having a minimum totalmedia depth of eleven inches (11"), if usingfilter media except for sand media.

4. Have an effective size in the range offour-tenths millimeter to sixty-five hun-dredths millimeters (0.40 mm-0.65 mm) anda uniformity coefficient of one and one half(1.5) or less, if utilizing sand media;

5. Include inlet ports located throughoutthe length of the filter.

6. Provide an underdrainage systemalong the entire length of the filter so that fil-ter effluent is uniformly withdrawn withoutclogging outlet openings.

7. Have a traveling bridge mechanismwhich—

A. Provides support and access to thebackwash pumps and equipment;

B. Is constructed of corrosion resis-tant materials;

C. Provides for consistent tracking ofthe bridge;

D. Provides support of the powercords; and

E. Initiates a backwash cycle automat-ically when a preset head loss through the fil-ter media occurs.

(E) Cloth/Disc Filters. 1. Media Design. The media shall:

A. Have an average pore size of nolarger than thirty (30) microns;

B. Follow the manufacturer’s recom-mendations; and

C. Be chemical-resistant if the filterwill be exposed to chemicals, such as chlo-rine or disinfectants.

2. Filtration Rates and Hydraulics. Thedesign shall—

A. Base the filtration rate on theeffective submerged surface area of the mediaand provide a maximum filtration rate forpeak flow of not more than six and one halfgallons per minute per square foot (6.5gpm/sq ft) of submerged cloth media; and

B. Be able to treat the design flow ratewith one (1) filter unit in backwash mode.

(4) Microscreening. (A) Screen Material. The microfabric shall

be a material demonstrated to be durablethrough long-term performance data.

(B) Backwash. All backwash shall be recy-cled for treatment.

(5) In-stream Diffusers. (A) General.

1. The mixing zone shall not encroachon a drinking water intake, recreation area,or sensitive habitat, overlap the next down-stream outfall, or occlude a downstream trib-utary.

2. Diffuser installation requires notifica-tion and an Army Corps of Engineers permit.

(B) Diffuser Design Criteria. 1. The pipeline shall be contained with-

in approved property boundaries or ease-ments.

2. Maximum port velocity shall notexceed fifteen feet per second (15 fps).



10 CSR 20-8.220 Land Treatment(Rescinded February 28, 2019)

AUTHORITY: section 644.026, RSMo Supp.1988. Original rule filed Aug. 10, 1978,effective March 11, 1979. Rescinded: FiledJune 15, 2018, effective Feb. 28, 2019.

10 CSR 20-8.300 Design of ConcentratedAnimal Feeding Operations

PURPOSE: This rule specifies the minimumstandards for the design of animal wastemanagement systems. It does not address allaspects of design, and the design engineermay refer to other appropriate referencematerials so long as these minimum stan-dards set forth in this rule are met.

PUBLISHER’S NOTE: The secretary of statehas determined that the publication of theentire text of the material which is incorpo-rated by reference as a portion of this rulewould be unduly cumbersome or expensive.This material as incorporated by reference inthis rule shall be maintained by the agency atits headquarters and shall be made availableto the public for inspection and copying at nomore than the actual cost of reproduction.This note applies only to the reference mate-rial. The entire text of the rule is printedhere.

(1) Applicability. This rule applies to all new


Secretary of State


or expanding Concentrated Animal FeedingOperations (CAFOs), however, only thoseapplicants that are constructing earthenbasins are required to obtain constructionpermits. The Missouri Department of NaturalResources (department) will not examine theadequacy or efficiency of the structural,mechanical, or electrical components of theconcentrated animal feeding operation sys-tems, only adherence to rules and regula-tions.

(2) Permit Application Documents. All engi-neering documents shall be prepared by, orunder the direct supervision of, a registeredprofessional engineer licensed to practice inMissouri.

(3) Location.(A) Protection from Flooding—Manure

storage structures, confinement buildings,open lots, composting pads, and othermanure storage areas in the production areashall be protected from inundation or damagedue to the one hundred- (100-) year flood.

(B) The minimum setback distances frommanure storage structures, manure storageareas, confinement buildings, open lots, ormortality composters shall be as follows:

1. Ten feet (10') to public water supplypipelines;

2. Fifty feet (50') to property lines;3. Fifty feet (50') to public roads;4. One hundred feet (100') to wetlands,

ponds, or lakes not used for human watersupply;

5. One hundred feet (100') to gainingstreams (classified or unclassified; perennialor intermittent);

6. Three hundred feet (300') to humanwater supply lakes or impoundments; and

7. Three hundred feet (300') to losingstreams (classified or unclassified; perennialor intermittent) and sinkholes.

(C) Distances from earthen basins shall bemeasured from the outside edge of the top ofthe berm.

(4) Manure Storage Structure Sizing.(A) No Discharge Requirement. All

manure storage structures shall comply withthe design standards and effluent limitationsof 10 CSR 20-6.300(4).

(B) Design Storage Period. The minimumdesign storage period for manure storagestructures shall be as follows:

1. The minimum design storage periodfor liquid manure, solid manure, and dry pro-cess waste to be land applied is one hundredeighty (180) days;

2. The minimum design storage periodfor solid manure and dry process waste to be

sold or used as bedding is ninety (90) days;and

3. The minimum design storage periodfor waste treatment lagoons without animpermeable cover is three hundred sixty-five (365) days.

(C) New Class I swine, veal, or poultryoperations shall evaluate proposed uncoveredmanure storage structures in accordance withapplicable federal regulation as set forth in 40CFR 412.46(a)(1), November 20, 2008, andshall hereby be incorporated by reference,without any later amendments or additions,as published by the Office of the Federal Reg-ister, National Archives and Records Admin-istration, Superintendent of Documents,Pittsburgh, PA 15250-7954.

(D) Sizing Manure Storage Structures.1. The structure shall be designed to

hold all inputs, between the upper and loweroperating levels, anticipated during the designstorage period.

2. Uncovered liquid storage structuresshall also include:

A. One in ten (1-in-10) year rainfallminus evaporation from the surface of thestructure, held between the operating levels;and

B. Safety volume based on the twen-ty-five (25) year, twenty-four (24) hour stormevent above the upper operating level.

3. Tanks and pits shall also include sixinches (6") of depth below the lower operat-ing level for incomplete removal allowance.

4. Earthen basins shall also include:A. At least one foot (1') of freeboard

or two feet (2') for structures that receivestorm water from open lots larger than thesurface area of the storage structure;

B.Two feet (2') of permanent liquiddepth below the lower operating level. Anaer-obic treatment volume greater than two feet(2') will satisfy this requirement;

C. Sludge accumulation volume; andD. Treatment volume below the lower

operating level for anaerobic treatmentlagoons.

(5) Construction of Earthen basins.(A) Geohydrologic Evaluation. A geohy-

drologic evaluation of the proposed earthenbasin prepared by the Missouri GeologicalSurvey shall be submitted to the department.If the geohydrologic evaluation gives a severerating for collapse potential, an earthen basinshall not be used.

(B) Detailed Soils Investigation. A detailedsoils investigation is required to substantiatefeasibility and to determine the quantity andquality of soil materials on-site and from aborrow area for use in the basin and/or liner.The following information, in whole or in

part, is required:A. Atterburg limits;B. Standard proctor density (mois-

ture/density relationships);C. Coefficient of permeability (undis-

turbed and remolded);D. Depth to bedrock;E. Particle size analysis; andF. Depth to groundwater table.

(C) Shape and Location.1. The shape of all cells shall be such

that there are no narrow or elongated portionsor islands, peninsulas, or coves.

2. The floor of the structure shall be aconsistent elevation with finished elevationsnot be more than three inches (3") above orbelow the average elevation of the floor.

3. The floor of the basin shall be at leastfour feet (4') above the groundwater table orthe water table as modified by subsurfacedrainage and at least two feet (2') abovebedrock.

(D) Outer berm slopes shall not be steeperthan three to one (3:1), horizontal to vertical,and inner slopes not be flatter than four toone (4:1) or steeper than three to one (3:1)for uncovered lagoons or two and one-half toone (2.5:1) for covered lagoons.

(E) Berm Construction and Width. Con-struction specifications shall include the fol-lowing:

1. Compact soil used in constructing thebasin floor (not including clay liner) andberm cores to between two percent (2%)below and four percent (4%) above the opti-mum water content and to at least ninety per-cent (90%) standard proctor density;

2. Use lifts for berm construction notexceeding twelve inches (12") with a maxi-mum rock size not exceeding one-half (1/2)the thickness of the compacted lift; and

3. Construct the top width of the berm aminimum of eight feet (8') for fill heightsfrom fifteen to twenty feet (15'–20'), useminimum top widths of ten feet (10') and forfill heights from twenty to twenty-five feet(20'–25'), use minimum top widths of twelvefeet (12').

(F) Emergency Spillway. To prevent over-topping and cutting of berms, an emergencyoverflow shall be provided that—

1. Has a minimum bottom width of tenfeet (10') and a minimum depth of one foot(1'); and

2. Is compacted and vegetated or other-wise constructed to prevent erosion due topossible flow.

(G) Compacted Clay Liner. 1. Liner construction. Compacted clay

liners shall be constructed to—



A. Be scarified and compacted tobetween two percent (2%) below and fourpercent (4%) above the optimum water con-tent and to at least ninety percent (90%) stan-dard proctor density.

B. Be raised in lifts not exceeding sixinches (6") with a maximum rock size notexceeding one-half (1/2) the thickness of thecompacted lift.

C. Be maintained at or above the opti-mum water content until the basin is prefilledwith water.

D. Have a minimum thickness oftwelve inches (12").

2. Permeability. All earthen basins shallbe sealed so that seepage loss through the sealis minimized and to meet the following spec-ifications:

A. Cover the floor and extend up theinner slope to where the side slope intersectswith the top of the berm.

B. Have a design permeability of thebasin seal not exceeding 1.0 x 10-7 centime-ter per second (cm/sec). For soils which havea coefficient of permeability greater than 1.0× 10-7 (cm/sec), unusual depth, or potableground water contamination potential, linerthickness of more than twelve inches (12")may be required. The following equationshall be used to determine minimum sealthickness:

t = (H×K)/ 5.4 × 10-7cm/sec

where K = permeability coefficient of the soil inquestion;H = head (maximum water level depth) ofwater in the basin; andt = thickness of the soil seal.

(H) Protection of Berms. Rip-rap or someother acceptable method of erosion control isrequired as a minimum around all pipingentrances and exits, for aerated cell(s), on theslopes and floor in the areas where turbu-lence will occur, and for protection fromwave action for basins with a surface areagreater than five (5) acres.

(I) If alternative liners are used, perme-ability, durability, and integrity of the pro-posed materials must be satisfactorily demon-strated for anticipated conditions.

(J) Depth Gauges. A permanent depthmeasurement gauge or marker shall beinstalled and maintained in the basin that iseasily readable at one-foot (1') or smallerincrements and clearly displayed lower,upper, and emergency spillway levels.

(K) Piping. Fill around pipes installedthrough embankments shall be compacted toprevent seepage and pressurized piping mustbe valved. Valves are not required on gravity

piping into the lagoon.(L) Safety. Consideration shall be given for

safety in using open storage structures includ-ing the use of prevention and recovery com-ponents.

(M) Operation and Maintenance. An oper-ation and maintenance plan is requiredaddressing the major components of the con-centrated animal feeding operation system.

(6) Construction of Tanks and Pits. Construc-tion of tanks and pits shall meet the followingrequirements:

(A) Soils and Foundation. A thorough siteinvestigation shall be made to determine thephysical characteristics and suitability of thesoil and foundation for the fabricated storagestructure. Position the floor of the below-ground storage tanks two feet (2') above thegroundwater table;

(B) Allow one foot (1') of depth at the topof covered structures for agitation and/or ven-tilation;

(C) Include a permanent depth measure-ment gauge or marker that is easily readableat one-foot (1') or smaller increments foruncovered tanks and pits;

(D) Use perimeter tiling and granularbackfill for below-ground pits;

(E) Locate tank and pit footings at orbelow the maximum frost depth;

(F) Design concrete and steel featuresaccording to published guidelines; and

(G) Design and construct tanks and pits tobe watertight.

(7) Construction of Solid Manure Compo-nents. The following requirements shall bemet when constructing poultry buildings,open lots, stacking pads, stacksheds, andother similar structures:

(A) Divert surface water away from animalconfinement areas and buildings;

(B) Floors and Pads. Construct the base ofcovered and uncovered lots, poultry build-ings, and other solid manure storage areas ofconcrete or other rigid, essentially watertightmaterials or from a firm, compacted, earthenbase of Unified Soil Classification System(USCS) class CH, MH, CL, GC, or SC soilsa minimum of two feet (2') above the ground-water table and be at least two feet (2') abovebedrock;

(C) Uncovered solids storage areas mustalso meet the following:

1. Have an overall slope between twopercent (2%) and four percent (4%) forunpaved lots;

2. Be maintained in a way that preventsponding; and

3. Have a runoff collection structure thatmeets the requirements of this rule.

(8) Design and Construction of Pipelines,Pump Stations, and Land Application Sys-tems.

(A) General. Design of pipelines shall bebased on the following requirements:

1. Ensure the storage/treatment facilitiescan be emptied within the time limits statedin the nutrient management plan;

2. Convey the required flow withoutplugging, based on the type of material andtotal solids content;

3. Install at a depth sufficient to protectagainst freezing;

4. Install with appropriate connectiondevices to prevent contamination of private orpublic water supply distribution systems andgroundwater;

5. Size pumps to transfer material at therequired system head and volume;

6. Install a minimum of three feet (3')below the natural stream floor and as nearlyperpendicular to the stream flow as possible;

7. Encase when buried under publicroads; and

8. Separation from potable water lines.Pipelines shall be located at least ten feet(10') horizontally from and at least eighteeninches (18") below the base of any potablewater line.

9. Aerial pipeline crossings of streamsshall:

A. Provide support for all joints inpipes utilized in the crossing;

B. Protect from the impact of floodwaters and debris; and

C. Be constructed so that they willremain watertight and free from changes inalignment or grade.

(B) Gravity Pipelines. Design of pipelinesshall be based on the following requirements:

1. Use a minimum slope of one percent(1%) for four inch (4") pipe, six-tenths per-cent (0.6%) for six inch (6") pipe, and four-tenths percent (0.4%) for eight inch (8")pipe;

2. Design with clean-outs at a maximuminterval of three hundred feet (300') and withmaximum horizontal curves of ten (10)degrees at pipe joints; and

3. Design gravity discharge pipes usedfor emptying a storage/treatment structurewith a minimum of two (2) valves in series.

(C) Force Mains and Pressure Pipes.Design velocities shall be between three (3)and six (6) feet per second.

(D) Testing. Hydro-pressure tests shall bemade only after the completion of backfillingoperations and for a minimum of one (1) hourusing a minimum test pressure of the maxi-mum system operating pressure.

(E) Pump Stations.1. Water supply protection. Manure


Secretary of State


pump stations shall not be connected to apotable water supply and shall be located atleast three hundred feet (300') from anypotable water supply well.

2. Alarm systems. Alarm systems arerequired for pumping stations that are activat-ed in cases of power failure, pump failure, orany cause of high water in the wet well.

(F) Land Application Systems. Land appli-cation systems shall be designed with:

1. Spray application equipment specifiedthat minimizes the formation of aerosols;

2. The pumping system and distributionsystem sized for the flow and operating pres-sure requirements of the distribution equip-ment and the application restrictions of thesoils and topography;

3. Provisions for draining the pipes toprevent freezing, if pipes are located abovethe frost line;

4. A suitable structure provided foreither a portable pumping unit or a perma-nent pump installation, the intake to thepumping system providing the capability forvarying the withdrawal depth, the intake ele-vation maintained twelve to twenty-four inch-es (12"–24") below the liquid elevation, theintake screened so as to minimize clogging ofthe sprinkler nozzle or distribution systemorifices, and, for use of a portable pump, astable platform and flexible intake line withflotation device to control depth of intake;

5. Thrust blocking of pressure pipes;and

6. An automatic pump or engine shut-offs in case of pressure drop.

(9) General System Details.(A) Mechanical Equipment. Mechanical

equipment shall be used and installed inaccordance with manufacturers’ recommen-dations and specifications and major mechan-ical units installed under the supervision ofthe manufacturer’s representative.

(B) Potable Water Supply Protection. Nopiping or other connections shall exist in anypart of the concentrated animal feeding oper-ation system, which under any conditions,might cause the contamination of a potablewater supply.

(10) Mortality Management. Class I opera-tions shall not use burial as a permanent mor-tality management method to dispose of rou-tine mortalities.

AUTHORITY: sections 640.710 and 644.026,RSMo 2016.* Original rule filed July 14,2011, effective April 30, 2012. Amended:Filed Jan. 26, 2016, effective Oct. 30, 2016.Amended: Filed June 15, 2018, effective Feb.28, 2019.

*Original authority: 640.710, RSMo 1996 and 644.026,RSMo 1972, amended 1973, 1987, 1993, 1995, 2000,2012, 2014.

10 CSR 20-8.500 Design Requirements forAgrichemical Facilities

PURPOSE: This rule specifies the minimumstandards for the design of agrichemicalfacilities. It does not address all aspects ofdesign, and the design engineer may refer toother appropriate reference materials so longas these minimum standards set forth in thisrule are met.


(1) Applicability. This rule applies to all agri-chemical facilities and to the construction ofnew secondary and operational containmentof agrichemicals at existing facilities. Allfacilities to which this rule applies shall bedesigned as no-discharge systems.

(2) Exceptions.(A) The prohibition of storing bulk liquid

fertilizer in a mobile container for more thanthirty (30) days shall not apply to barges andrail cars used solely for transporting liquidfertilizer from chemical production facilitiesto retail or wholesale facilities.

(B) The prohibition of burying pipes usedfor transferring full strength agrichemicalsshall not apply to piping used solely for theloading and unloading of liquid fertilizerfrom barges and rail cars. These pipes shallbe pressure tested on a yearly basis to certifythe integrity of the pipes. Records of the pres-sure testing shall be kept on file at the facili-ty and made available to Missouri Depart-ment of Natural Resources (department)personnel upon request.

(C) Liquid fertilizer storage tanks that werein use prior to January 13, 1992, having astorage capacity greater than forty thousand(40,000) gallons are exempt from the require-ment of installing a liner underneath the tankitself. Spill containment diking is requiredaround these tanks.

(3) Engineering Report. An engineeringreport is required for all facilities required by10 CSR 20-6.010 to submit an application fora construction permit.

(4) Primary Containment for Bulk LiquidAgrichemicals for new construction. Con-tainers and appurtenances used as the prima-ry containment in the storage and handling ofbulk agrichemicals shall be constructed,installed, and maintained to prevent a dis-charge and shall be of materials and con-struction compatible with the specificationsof the product stored with:

(A) Tank anchors or raised stands;(B) For self-supporting tanks, the ability to

handle all operating stresses, hydrostatichead, pressure buildup from pumps and com-pressors, and any other mechanical stressesto which the containers and appurtenancesmay be subject to in the foreseeable course ofoperation;

(C) No external sight gauges used withbulk pesticide storage containers;

(D) Lockable valves for bulk liquid fertil-izer containers located between the sightgauge and the storage container;

(E) A lockable main discharge valve;(F) All appurtenances protected against

damage from operating personnel and movingvehicles and located within the secondarycontainment or operational containment area;

(G) All storage structures for bulk liquidpesticides or bulk liquid fertilizers locatedabove ground; and

(H) Secure transfer hose connections.

(5) Secondary Containment for Bulk LiquidAgrichemicals for new construction. Sec-ondary containment for nonmobile bulk liq-uid pesticides and nonmobile bulk liquid fer-tilizers shall be designed to contain anyspilled product to prevent a discharge with—

(A) Containment structures sized accord-ing to the Environmental Protection Agency’sCode of Federal Regulations, 40 CFR165.85, published July 1, 2014. This docu-ment shall hereby be incorporated by refer-ence without any later amendments or modi-fications. To obtain a copy, contact the U.S.Government Printing Office at 732 NorthCapitol Street NW, Washington, DC, 20401,toll free at (866) 512-1800 or by visitinghttps://bookstore.gpo.gov;

(B) No discharge outlet or gravity drainthrough the wall or floor of the containmentstructure;

(C) The walls and floors constructed ofmaterial that is compatible with the specifica-tions of the product being stored; resistant topenetration by moisture and agrichemicals;and designed to support the gravity load of



the storage containers and any hydrostaticloads that would result from a massive spillwithin the containment structure;

(D) Expansion joints spaced to preventcracks from forming; sealed with a materialresistant to agrichemicals; and with waterstops installed between the containment wallsand floor;

(E) A collection sump, if needed, shall notbe more than two feet (2') deep or larger thantwenty (20) cubic feet; constructed of materi-als that resist penetration by moisture andagrichemicals; with a sealed connection pointbetween the containment area floor; and at alow point in the containment area to allow forremoval of accumulated liquids;

(F) No piping installed through the wallsor floor except for through common, inter-connecting containment walls and all pipingentering and leaving the secondary contain-ment structure shall go up and over the con-tainment walls;

(G) No buried transfer piping;(H) Separation of bulk liquid pesticides

and bulk liquid fertilizers with a commonwall and with no interconnecting piping; and

(I) All tanks for storage of rinsate or pre-cipitation collected in the secondary or oper-ational containment area located within a sec-ondary containment structure.

(J) Earthen structures used for secondarycontainment shall be designed as follows:

1. Be constructed with a compacted soilliner or synthetic liner with a permeabilityrate of 1 × 10-7 cm/sec. or less.

2. Be protected against erosion with sideslopes no steeper than three to one (3:1) andwith a top width no less than two and one-half feet (2 1/2').

(6) Nonmobile bulk dry fertilizer storageshall be designed to—

(A) Be stored inside a sound structure toprevent contact with precipitation with allsurface water runoff diverted away from thestorage structure;

(B) Allow for all unloading, loading, mix-ing, and handling of dry bulk fertilizers to bedone on an operational containment area asrequired in section (9) of this rule;

(C) Have an adequately sized operationalcontainment area to hold the volume of pesti-cides used and impregnation equipment asrequired in section (9) of this rule;

(D) Allow for daily cleanup of the dry fer-tilizer loading, unloading, mixing, and han-dling areas;

(E) Prevent the downward movement offertilizer materials and moisture through thefloor with expansion joints spaced to preventcracks from forming and sealed with a mate-rial resistant to agrichemicals; and

(F) Have a mixing and loading pad con-structed under any exterior transfer area of aconveyance system.

(7) Nonmobile bulk dry pesticide storageshall be designed to—

(A) Be stored inside a sound structure toprevent contact with precipitation and with allsurface water runoff diverted away from thestorage structure;

(B) Allow for all loading, mixing, and han-dling of bulk dry pesticides to be done on anoperational containment area;

(C) Allow for daily cleanup of the bulk drypesticide loading, unloading, mixing, andhandling areas;

(D) Prevent the downward movement ofpesticides and moisture through the floorwith expansion joints spaced to preventcracks from forming and sealed with a mate-rial resistant to agrichemicals; and

(E) Have a mixing and loading pad underany exterior transfer area of a conveyancesystem.

(8) Operational containment for bulk liquidpesticides and bulk liquid fertilizers for newconstruction shall be designed to:

(A) Divert runoff away from the opera-tional containment area;

(B) Contain any spilled product and anycollected precipitation that comes in contactwith spillage for the amount of time neededfor proper cleanup and recovery;

(C) Have a minimum volume in accor-dance with the Environmental ProtectionAgency’s Code of Federal Regulations, 40CFR 165.85, published July 1, 2014. Thisdocument shall hereby be incorporated byreference without any later amendments ormodifications. To obtain a copy, contact theU.S. Government Printing Office at 732North Capitol Street NW, Washington, DC,20401, toll free at (866)512-1800 or by visit-ing https://bookstore.gpo.gov;

(D) Have a sediment trap and sump, ifneeded, not more than two feet (2') deep orlarger than 20 cubic feet and constructed ofmaterials that resist penetration by moistureand agrichemicals with a sealed connectionpoint between the operational containmentarea floor and the sump to prevent leakage ofliquids from the containment area;

(E) Extend beneath any pump, appurte-nance, or plumbing connection not locatedwithin the secondary containment area andthat is used to transfer liquid fertilizer or pes-ticide; and

(F) Allow for bulk repackaging contain-ment of agrichemicals.

(9) Operational Containment Area for bulk

dry pesticides and bulk dry fertilizers for newconstruction shall be sized to—

(A) Divert runoff away from the opera-tional containment area;

(B) Contain any spillage of dry materialsthat occurs from loading, unloading, or haul-ing; from spreading equipment; and frommixing and blending equipment. Operationalcontainment areas must also contain precipi-tation that comes in contact with spillage forthe amount of time needed for proper cleanupand recovery;

(C) Individual catchment basins orportable pans/containers may be used to sat-isfy the requirement for operational contain-ment. The individual basins or portable con-tainers shall be placed to catch or recoverspillage and leakage from transfer connec-tions and conveyors; and

(D) For unloading dry pesticides and dryfertilizers from rail cars, a catchment basin orconcrete pad that can effectively contain thedry fertilizer or pesticide shall be used.

(10) Connection to Water Supplies. An air gapseparation or reduced pressure principle back-flow prevention assembly shall be installed inthe water supply line that serves an agrichem-ical facility. The air gap or backflow preven-tion assembly shall be constructed, installed,and inspected in accordance with 10 CSR 60-11.010 Prevention of Backflow.

(11) Protection from Flooding. All agrichem-ical facilities shall be located so that the agri-chemicals being stored are protected from aone hundred- (100-) year flood event.

(12) Operation and Management of Agri-chemical Facilities. Field application of rin-sate and collected precipitation is acceptableand recommended.

AUTHORITY: sections 644.026 and 644.036,RSMo 2016.* Original rule filed July 15,1991, effective Jan. 13, 1992. Amended:Filed Aug. 1, 2016, effective April 30, 2017.Amended: Filed June 15, 2018, effective Feb.28, 2019.

*Original authority: 644.026, RSMo 1972, amended1973, 1987, 1993, 1995, 2000, 2012, 2014 and 644.036,RSMo 1972, amended 1973, 2000, 2002, 2006, 2009,2011.


Secretary of State
