Federal Register / Vol. 51, No. 163 / Friday, August 22, 1986 / Proposed Rules

ENVIRONMENTAL PROTECTIONENVIRONMENTAL PROTECTIONAGENCY

40 CFR Ch. I

LEN FRL-3046-71

Preliminary Approaches toImplementing the Recommendationsof the Domestic Sewage Study;Advance Notice of ProposedRulemaking

AGENCY: Environmental ProtectionAgency (EPA).ACTION: Advance notice of proposedrulemaking.

SUMMARY: In 1984, Congress enacted theHazardous and Solid WasteAmendments (HSWA) to the ResourceConservation and Recovery Act(RCRA). Section 3018(a) of RCRA, asamended, directed EPA to submit areport to Congress concerning wastesdischarged through sewer systems topublicly owned treatment works(POTWs) that are exempt from RCRAregulation as a result of the DomesticSewage Exclusion of RCRA. This report(the Domestic Sewage Study, hereinafterreferred to as "the Study") was preparedby EPA's Office of Water and submittedto Congress on February 7, 1986. TheStudy examined the nature and sourcesof hazardous wastes discharged toPOTWs, measured the effectiveness ofAgency programs in dealing with suchdischarges, and recommended ways toimprove the programs to achieve bettercontrol of hazardous wastes enteringPOTWs.

As a follow-up to the Study, section3018(b) of RCRA directs theAdministrator to revise existingregulations and promulgate suchregulations as are necessary to assurethat hazardous wastes discharged toPOTWs are adequately controlled toprotect human health and theenvironment. The regulations must bepromulgated within eighteen monthsafter submission of the Study toCongress (August 1987).

The Agency is today publishing anAdvance Notice of ProposedRulemaking (ANPR) which will be thefirst step towards promulgating theregulations required by section 3018(b).EPA wishes to use today's noticeprimarily to obtain public comments andsuggestions on possible ways toimplement or address therecommendations of the Study. TheAgency will then evaluate the commentsand suggestions and use them to helpprepare specific proposed rules forpublication. Today's notice contains noformal proposals for regulatoryamendments. Instead, EPA suggests a

range of preliminary approaches toimproving the control of hazardouswastes discharged to the nation'sPOTWs. The Agency solicits commentson these approaches and invitessuggestions on any other approaches thepublic believes appropriate.DATES: Comments must be received onor before October 21, 1986.ADDRESS: Comments should beaddressed to Ms. Marilyn Goode,Permits Division (EN-336), U.S.Environmental Protection Agency, 401 MStreet SW., Washington, D.C. 20460,(202) 475-9534.FOR FURTHER INFORMATION CONTACT:Ms. Marilyn Goode, Permits Division,(EN-336), U.S. Environmental ProtectionAgency, 401 M Street SW., Washington,D.C. 20460, (202) 475-9534.

For copies of the Domestic SewageStudy, contact Ms. Carol Swann,Industrial Technology Division (WH-552), U.S. Environmental ProtectionAgency, 401 M St. S.W., Washington,D.C. 20460, (202) 382-7137.SUPPLEMENTARY INFORMATION:

I. Statutory Background

The origins of the Study lie in theDomestic Sewage Exclusion of RCRA.The exclusion, established by Congressin section 1004(27) of RCRA, providesthat solid or dissolved material indomestic sewage is not solid waste asdefined in RCRA. A corollary is thatsuch material also cannot be considereda hazardous waste for purposes ofRCRA.

The regulatory exclusion applies todomestic sewage as well as mixtures ofdomestic sewage and other wastes thatpass through the sewer system to aPOTW (see 40 CFR 261.4(a)(1)). Theexclusion thus covers industrial wastesdischarged to POTW sewers whichcontain domestic sewage, even if theindustrial wastes would otherwise beconsidered hazardous wastes.

Under the exclusion, industrialfacilities which discharge such wastesto sewers containing domestic sewageare not subject to RCRA generator andtransporter requirements, such asmanifesting and reporting. In addition,POTWs receiving such wastes mixedwith domestic sewage are not therebydeemed to have received hazardouswastes and therefore need not complywith certain RCRA hazardous wastetreatment, storage, and disposalrequirements with respect to thesewastes. However, the Domestic SewageExclusion does not apply to sludgeproduced by a POTW as a result ofwastewater treatment if such sludge isfound to be a RCRA characteristicwaste under 40 CFR 261 Subpart C. In

addition, hazardous wastes delivered toa POTW by truck, rail, or dedicated pipeare not covered by the Domestic SewageExclusion, and are subject to regulationunder the RCRA permit-by-rule (see 40CFR Part 270.60(c)).

The legislative history of RCRAindicates that the Domestic SewageExclusion stems from the assumptionthat the pretreatment program of theClean Water Act (CWA) can ensureadequate control of industrialdischarges to sewers. This program,mandated by section 307(b) of the CWAand implemented in 40 CFR Part 403,provides for pretreatment by industrialfacilities of pollutants discharged toPOTWs, to the extent that suchpollutants would interfere with, passthrough, or otherwise be incompatiblewith the operations of POTWs. TheExclusion avoids the potentialregulatory redundancy of subjectinghazardous wastes mixed with domesticsewage to RCRA managementrequirements if these wastes are alreadysubject to appropriate pretreatmentrequirements under the CWA.

In 1984, Congress enacted theHazardous and Solid WasteAmendments to RCRA. The legislativehistory of these amendments revealsthat Congress wanted EPA to evaluatethe effects of the Domestic SewageExclusion. Congressman Molinari(R.N.Y.), one of the sponsors of theamendment, expressed concern aboutpossible gaps in RCRA which couldthreaten public health and theenvironment. He stated that EPA should:... quantify, as accurately as possible, thenature and scope of hazardous wastedisposal into domestic sewers . . . theextent to which the exclusion isjustified . . . and the adequacy ofpretreatment as a means of dealing with theproblem. [CONG. REC. H9150 (daily ed.November 3, 1983), emphasis added]

To this end, section 3018(a) of theHazardous and Solid WasteAmendments to RCRA required EPA toprepare:... a report to Congress concerning those

substances identified or listed under section3001 which are not regulated under thissubtitle by reason of the exclusion formixtures of domestic sewage and other,wastes that pass through a sewer system to apublicly owned treatment works. Such reportshall include the types, size, and number ofgenerators which dispose of substances inthis manner, and the identification ofsignificant generators, wastes, and wasteconstituents not regulated under existingFederal law or regulated in a mannersufficient to protect human health and theenvironment.

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Section 3018(b) then requires theAdministrator to revise existingregulations and to promulgate suchadditional regulations as are necessaryto ensure that hazardous wastesdischarged to POTWs are adequatelycontrolled to protect human health andthe environment. These regulations areto be promulgated pursuant to RCRA,section 307 of the CWA, or any otherappropriate authority possessed by EPA.The regulations must be promulgatedwithin eighteen months after submissionof the Study to Congress (August 1987).

!I. Summary of the Domestic SewageStudy

EPA submitted the Study to Congresson February 7, 1986. In performing theStudy, the Agency reviewed informationon 160,000 waste dischargers from 47industrial categories and the residentialsector. Because of the nature of theavailable data sources, the Studyprovided estimates for the discharge of165 specific constituents of hazardouswaste (e.g., benzene, acetone, etc.)rather than estimates for hazardouswastes as they are more generallydefined under section 3001 of RCRA(i.e., characteristic wastes such asignitable or reactive materials, or listedwastes such as spent solvents,electroplating baths, etc.).

Data limitations also led the Study toprovide more extensive estimates forthose hazardous constituents which arealso CWA priority pollutants. The CWApriority pollutant list was originallydeveloped as part of a settlementagreement between the NaturalResources Defense Council (NRDC) andEPA (NRDG v. Train, 8 ERC 2120 (D.D.C.1976)). This agreement required theAgency to promulgate technology-basedstandards for 65 compounds or classesof compounds. Congress thenincorporated this list of toxic pollutantsas part of the 1977 amendments to theCWA. From the list of compounds orclasses of compounds, EPA laterdeveloped a list of 126 individualpriority pollutants.

A more thorough assessment ofhazardous waste discharges depends oncollecting additional data on dischargesof non-priority hazardous wastes toPOTWs. Furthermore, the Agencypossesses little knowledge about thebehavior and effects of many hazardousconstituents in aqueous solutions. Inparticular, the Study determined thatlittle is known about groundwatercontamination as a result of exfiltration(leakage) from POTW systems or airemissions due to the volatilization ofindustrial wastes discharged to sewers.

In spite of these limitations, EPA was

able to give estimates in the Study onthe types, sources, and quantities ofmany hazardous constituents dischargedto POTWs. The Study providesinformation on industrial categoriesranging from the largest hazardouswaste generators (such as the organicchemicals and petroleum refiningindustries) to small quantity generators(such as laundries and motor vehicleservices). In selecting hazardousconstituents to be included in the Study,EPA took care to choose those whichseemed representative of actualindustrial discharges. For example, theStudy emphasized hazardousconstituents for which nationalproduction rates are high (as opposed tospecialty chemicals), as well asconstituents found in the wastestreamsof industries known to be significantgenerators of hazardous wastes.

The Study also examines the fate ofhazardous constituents once they aredischarged to POTW collection andtreatment systems and discusses thepotential for environmental effectsresulting from the discharge of theseconstituents after treatment by POTWs.The Study then measures theeffectiveness of government controls indealing with these discharges, payingparticular attention to federal and localpretreatment programs and categoricalpretreatment standards applicable toindustrial users of POTWs.

After considering all the pertinentdata, EPA concluded that the DomesticSewage Exclusion should be retained atthe present time. The Study found thatCWA authorities are generally the bestmethod of controlling hazardous wastedischarges to POTWs. However, theStudy also found that these authoritiesshould be more broadly and effectivelyemployed to regulate these discharges.The Study therefore recommended waysto improve various EPA programs underthe CWA to obtain better control ofhazardous wastes entering POTWs. Inaddition, the Study recommendedresearch efforts to fill certaininformation gaps, and indicated thatother statutes (such as RCRA and theClean Air Act) should be consideredalong with the CWA to controlhazardous waste dischargers and/orreceiving POTWs if the recommendedresearch indicates the presence ofproblems not adequately addressed bythe CWA. These recommendations arediscussed in Part IV below.111. Public Participation

As stated earlier, EPA wishes toobtain through this notice suggestionsand comments from the public about thebest ways to deal with the problem of

hazardous wastes discharged into thenation's municipal treatment plants. Forthis reason, the Agency is not proposingany specific regulatory amendments atthis time. Some of the regulatory effortsin which EPA has been and continues tobe engaged under the CWA are relateddirectly to the recommendations of theStudy. Where relevant, these efforts aredescribed below. Generally, however,EPA is today presenting a range of newideas that could be starting points forspecific future regulatory proposals that,when implemented, would improvecontrol of hazardous wastes dischargedto POTWs. EPA invites comment onthese ideas and actively solicitscomments and suggestions on any otheralternative methods of dealing with theproblems discussed by the Study.

Besides inviting comments on themerits of all approaches, the Agencyalso requests comments on the resourceimplications of all alternativesuggestions, since such implicationsmust be taken into account when EPAselects options for formal proposals andfinal rulemakings.

The Agency believes that wide publicparticipation is essential to help EPAselect, the best choices among allavailable options. To this end, theAgency has announced in a separateFederal Register notice three publicmeetings to be held after today's ANPRis published (51 FR 29499, August 18,1986). The meetings will take place asfollows:

Hall of States, Skyline Inn, 101 St. SW,Washington, D.C. 20024--9:30 a.m.,September 11, 1986

Grand Ballroom North, SheratonInternational at O'Hare, 6810 NorthMannheim Road, Rosemont, Illinois60018-9:30 a.m., September 17, 1986

Continental Parlor, San Francisco Hiltonand Tower, 333 O'Farrell Street, SanFrancisco, California 94102-10:00a.m., September 18, 1986

Each meeting will last forapproximately four hours. All interestedpersons are invited to attend.

In addition to holding public meetingsand evaluating comments received inresponse to today's notice, the Agencyplans to consult interested groups andorganizations (including environmentalgroups, industry trade associations, andState and local pollution controlauthorities) to obtain the benefit of theiradvice and expertise. EPA will thenpublish formal proposals, followed bypromulgation of final rules.

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IV. Recommendations of the DomesticSewage Study and PreliminaryApproaches Toward TheirImplementation

The Study summarizes itsrecommendations for improvement ofEPA programs as follows:

. Improvements can be made tofederal categorical standards and localpretreatment controls to enhance controlof hazardous wastes discharged tosewers;

e EPA should emphasizeimprovement of controls on hazardouswastes through ongoing implementationof water programs, includingenforcement, sludge management, andwater quality programs;

* Additional research is necessary onthe sources and quantities of hazardouswastes, their fate and effects in POTWsystems and the environment, and thedesign of any additional regulatorycontrols that might be necessary;

9 RCRA, CERCLA, and the CAAshould be considered along with theCWA to control hazardous wastedischarges and/or receiving POTWs ifthe recommended research indicates thepresence of problems.

The specific recommendations of theStudy are discussed in more detailbelow. The Agency's plannedapproaches to implementing theserecommendations are also described. Ineach case, comments are invited andany other new ideas are requested andwelcomed.

A. General Pretreatment Program

1. General and Specific ProhibitedDischarge Standards

As part of its evaluation of thenational pretreatment program, theStudy recommended modifying theprohibited discharge standards of thegeneral pretreatment regulations toimprove control of characteristichazardous wastes and solvents.

The prohibited discharge standardsforbid certain types of discharges toPOTWs from all industrial users(including those not regulated bycategorical pretreatment standards). Thegeneral prohibitions, (40 CFR 403.5(a))forbid discharges which pass throughthe POTW or interfere with its operationor performance. The specificprohibitions (40 CFR 403.5(b)) currentlyforbid the discharge of specific types ofmaterials which can harm POTWcollection and treatment systems. Theseare:

- Pollutants which create a fire orexplosion hazard;

- Pollutants which cause corrosivedamage;

e Pollutants which cause obstructionto flow within a POTW;

* Any pollutants discharged inconcentrations or flow rates whichcause interference with a POTW;

• Heat which inhibits POTWbiological activity.

With respect to the specific dischargeprohibitions, the Study suggested waysthat EPA might amend theseprohibitions to improve the control ofhazardous wastes. In particular, theStudy discussed expanding the list ofspecific prohibitions to include certaincharacteristics of hazardous wastesunder RCRA (i.e., wastes that aredeemed hazardous if they possesscertain characteristics). Thesecharacteristics of hazardous wastes areignitability, corrosivity, reactivity, andExtraction Procedure (EP) toxicity.

The existing specific prohibitionagainst pollutunts which create a dangerof fires and explosions could possibly beused to control discharges of certainRCRA characteristic wastes,particularly ignitable and reactivewastes. However, the current wording ofthe pretreatment prohibitions is generalin nature and may not be fully effectivein preventing the discharge of wastesexhibiting these characteristics.

With respect to the EP toxicitycharacteristic, the Agency will soonpropose a rule to expand thischaracteristic under RCRA to include 38additional organic chemicals and animproved leaching test (the ToxicityCharacteristic' Leaching Procedure, orTCLP). The new test method allowsbetter evaluation of organic pollutants(including volatiles), provides enhancedprecision and accuracy, solves severaloperational problems associated withthe EP protocol, and models effects ofleaching the constituents into theenvironment. However, there is somequestion about whether these testprocedures are appropriate fordetermining whether particularpollutants are likely to cause passthrough and interference. Materials maybe subsequently diluted when mixedwith large amounts of domestic sewage,and POTWs are capable of removingmany such materials even in smallamounts.

EPA believes that the current specificdischarge prohibitions for characteristicwastes are probably adequate to controlhazardous wastes which exhibit thecorrosion characteristic as definedunder RCRA. Further, as describedabove, a specific discharge prohibitionagainst wastes exhibiting the EP toxicitycharacteristic may be neitherappropriate nor necessary. Thereactivity and ignitability characteristicsmay be appropriate additions to the

specific discharge prohibitions under theCWA pretreatment program, and EPAcurrently plans to propose to add thesecharacteristics to 40 CFR 403.5(b). EPAsolicits comments on whether to modifythe specific prohibitions to include someor all characteristics of hazardouswastes under RCRA. (Comments on theTCLP procedure not related to thespecific prohibitions should besubmitted in the context of thatrulemaking.)

Alternatively, or perhaps inconjunction with this approach, theAgency could prohibit (absolutely orconditionally) the discharge to POTWsof some or all constituents of hazardouswaste identified in Appendix VIII of 40CFR Part 261. Some or all listedhazardous wastes (see 40 CFR 261.31-33)could be prohibited as well. The Agencycurrently believes that listed hazardouswastes and constituents of hazardouswastes may often be appropriatelyaddressed through local limits. Whilegenerally applicable dischargeprohibitions may be appropriate forsome wastes, constituents or classes ofconstituents found to cause pass throughor interference, EPA does not now planto develop general or specific dischargeprohibitions for all hazardous wastes.Nevertheless, the Agency would like toreceive comments on this method ofimplementing the recommendations ofthe Study.

With respect to the generalprohibitions against pass through andinterference (40 CFR 403.5(a)), theAgency solicits comments on whether orhow to reconsider the notion of whichactivities should constitute violations ofthese prohibitions. The definitions ofpass through and interference (40 CFR403.3 (i) and (n), currently suspended)were proposed on June 19, 1985 at 50 FR25526. Under these proposed definitions,interference occurs when an industrialuser's discharge (alone or in conjunctionwith other sources) causes a violation ofthe POTW's NPDES permit or preventssewage sludge use or disposal by thePOTW in accordance with applicablelaws. Similarly, pass through occurswhen pollutants discharged by anindustrial user (alone or in conjunctionwith other sources) pass through thePOTW into navigable waters inquantities or concentrations that, aloneor in conjunction with other sources,cause a violation of the POTW's NPDESpermit. POTWs are required to establishneeded local limits to prevent passthrough and interference.

The Study suggested that thesedefinitions are not fully effective incases where hazardous wastes, thoughpotentially harmful do not actually

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cause a violation of the POTW's NPDESpermit or applicable sludgerequirements. For example, it is possiblefor hazardous wastes discharged by anindustrial user to impair plant efficiency(producing toxicity or sludge problems)without actually causing the POTW toviolate its permit or applicable sludgerequirements. The addition of thehazardous waste may also producetoxicity without impairing the plant'streatment efficiency for the pollutantslimited in the permit. Likewise, the 'prohibition against pass through maynot be effective in regulating hazardouswastes if water quality-based effluentlimitations for toxic pollutants or totaltoxicity have not been specificallyincorporated in the POTW's permit. Inthat case a permit violation would notoccur regardless of the rate of discharge.

The Agency has encounteredconsiderable difficulty in promulgatingdefinitions of pass through andinterference that are acceptable tomembers of the regulated communityand that can withstand legal challenge(for a history of the relevent rulemakingsand a discussion of the issues raised inlitigation, see the preamble of the above-referenced Federal Register noticepublished on June 19, 1985).Nevertheless, EPA solicits usefulcomments on how these definitionsmight be amended in a way thatstrengthens control of hazardous wastedischarges while at the same time givingadequate notice to industrial users oftheir potential responsibilities. Onepossible approach that the Agency isactively considering is to retain thecurrent definitions of pass through andinterference for enforcement purposes,but to require local limits developmentfor pollutants of concern even if noPOTW permit violation occurs or isthreatened.

A second way to implement theprohibitions against pass through andinterference is to move aggressively toset toxicity-based limits in NPDESpermits issued to POTWs. Since findingsof pass through and interferencedepend, by EPA's regulatory definition,on a violation of the POTW's NPDESpermit, permit limits developed toprotect against toxicity or based ontoxicity testing would help POTWsdevelop local limits designed to avoidsuch violations. EPA has found that theeffluents from many POTWs exhibittoxicity, so testing for compliance withtoxicity-based limits should often serveas a reliable measure of whether passthrough or interference has occurred.Expanding the use of toxicity-basedpermit limits is one of the Agency'sprincipal goals, and EPA is currently

emphasizing this concern in its qualityreviews of NPDES State permitprograms (for a more detailed discussionof this issue, see Part IV-C-1 below).

A related way to implement theseprohibitions is to require that water-'quality based permit limits for POTWsbe established for additionalconstituents of hazardous waste likelyto cause pass through or interference.These limits, when violated, wouldserve as a basis for determininginstances of pass through or interferenceand for developing local limits designedto avoid such pass through andinterference. Although EPA believes thatthis method would be more difficult toimplement and would prefer toimplement the prohibitions by amendingthe definitions of pass through andinterference and by generally expandingthe use of toxicity-based permit limits,the Agency nevertheless solicitscomments on which constituents (if any)would be appropriate for additionalpermit limits.

2. Improvement of Controls on Spillsand Batch Discharges, IllegalDischarges, and Discharges by LiquidWaste Haulers

Spills and batch discharges, as well asillegal discharges and discharges byliquid waste haulers, present specialcontrol and operational challenges toPOTWs. Responses to an informal EPAquestionnaire submitted by members ofthe Association of MetropolitanSewerage Authorities (AMSA) indicatedthat spills and batch discharges tosewage treatment plants are frequentoccurrences. As documented by POTWincidents data, these discharges causemany problems at the treatment plant,including worker illness, actual orthreatened explosion, biological upset/inhibition, toxic fumes, corrosion, andcontamination of sludge and receivingwaters. Although some POTWs haveadopted spill control measures, othersare poorly prepared to cope with spillsand batch discharges of hazardouswastes from industries.

Likewise, many respondents in theAMSA survey indicated concern aboutdischarges from liquid waste haulers(legal and illegal) and "midnightdumpers" who utilize public sewers forillegal waste disposal. To address theseproblems, the Study recommendedstrengthening pretreatment regulatoryand program controls.

The current general pretreatmentregulations do not address theseproblems comprehensively, althoughpresent procedures may minimize someof the risks associated with thesesources. The principal pretreatmentregulation concerning spills is the

requirement that all industrial usersnotify POTWs of slug loads of pollutantdischarges that, because of volume orconcentration, will interfere with or passthrough the POTW (40 CFR 403.12). TheAgency recently proposed to expandthis requirement to include notificationof slug loads that.would violate any ofthe specific prohibitions of 40 CFR403.5(b) (see 51 FR 21454, June 12, 1986).

Several options are available tostrengthen the general pretreatmentregulations to deal with these problems.For example, the pretreatmentregulations might also be amended torequire all industrial users to undertakepreventive measures and institutefollow-up on spill incidents.Alternatively, or in addition, the Agencycould amend the regulations to requirethat POTWs develop their ownenforceable plans for accidental spillprevention and control. Many POTWsalready have such plans, and EPAbelieves that they hold promise in givingPOTWs better control of hazardouswastes entering their treatment andcollection systems. EPA's Region X hasadopted this approach, and reports thatit has been-successful.

With respect to discharges from liquidwaste haulers, these are subject to thesame categorical standards, general andspecific prohibitions, and local limitspresently in effect for any industrialuser. In addition, POTWs that receiveRCRA hazardous wastes by truck, rail,or dedicated pipe are not covered by theDomestic Sewage Exclusion of RCRA,and are therefore subject to regulationunder the RCRA permit-by-rule (40 CFR270.60(c)), which includes a requirementthat POTWs take corrective action forreleases at their own solid wastemanagement units.

One way to strengthen the presentcontrols on discharges from liquid wastehaulers would be to amend the generalpretreatment regulations to requirePOTWs to develop and obtain EPAapproval of procedures (in addition tothose presently required under RCRA)for dealing with trucked-in wastes(whether trucked to the POTWheadworks or to the sewer). Theseprocedures could include manifesting,monitoring, and sampling requirements.Another method would be to amend theregulations to ban the introduction ofhazardous wastes or constituents ofhazardous wastes to sewer systems bytruck except at specific pointsdesignated by the POTW (in addition tothe RCRA requirements alreadyapplicable to generators or transportersof hazardous wastes).

EPA believes that each of theseoptions would help improve controls on

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spills and batch discharges anddischarges by liquid waste haulers, andnow plans to propose regulations alongthe lines described above. The Agencysolicits comments or information on thenumber and types of local programswhich already have measures in placeto deal with such problems, andrequests alternative suggestions onways to address these concerns.

A related recommendation of theStudy was that EPA assess theincidence and effects of "midnightdumping" into sewers. Part of theAgency's follow-up effort on the Studyconsists of consulting groups such asstate and local water pollution controlagencies and AMSA who will be able tohelp EPA review the incidence of illegaldischarges of hazardous wastes tosewers. In this way, the Agency hopes tolearn more about the number andsignificance of these discharges todetermine whether it needs to develop amore effective program for their control.At present, it is unclear whether moreregulatory requirements would beuseful, or whether an aggressive policyof monitoring and enforcement is theonly-effective way to deal with theseillegal actions. The Agency invitescomment on this question. -

In the meantime, EPA is continuing itscriminal enforcement effort againstthese and other violators of the CleanWater Act. Investigators from the EPANational Enforcement InvestigationsCenter's Office of Criminal Investigationcontinue to follow leads and gatherevidence against illegal dischargers. Ifevidence exists that a crime has beencommitted, the case is referred first toEPA's Office of Criminal Enforcementand then, if warranted, to theDepartment of Justice or the appropriateU.S. Attorney's Office. Since 1983,several prosecutions have been initiatedfor willful illegal discharges into sewersor POTWs, all of which have resulted inconvictions and substantial fines. TheAgency will vigorously continue thiseffort to deter similar potential violators.

3. Notification Requirements

Proper notification to POTWs ofhazardous waste discharges is essentialto the control of such wastes. Withoutworkable notification requirements, anyfurther attempt to regulate hazardousconstituents discharged to POTWs isdifficult if not impossible.

Section 3010(a) of RCRA requires thatany person who generates or transportsa RCRA hazardous waste, or who ownsor operates a facility for the treatment,storage, or disposal of such waste, mustfile a notification with EPA or with aState with an authorized hazardouswaste permit program. Section 3018(d)

of RCRA (enacted as part of the HSWAin 1984) clarifies that wastes mixed withdomestic sewage are also subject to thisnotification requirement.. The Agency has not yet promulgatedregulations to implement the Section3018(d) notification requirements. TheStudy recommended that theserequirements be implemented to ensurethat regulatory authorities were awareof discharges of hazardous wastes toPOTWs. EPA presently plans to amendthe general pretreatment regulations torequire that industrial users notify theirPOTW (rather than EPA or the State) ofany constituents of hazardous wastesdischarged. In addition, EPA hasrecently proposed to require industrialusers to notify the POTW of certainchanges in their discharges (see 51 FR21454, June 12, 1986). The Agencysolicits comments on these and otherways to improve notificationrequirements (including amendments tothe RCRA regulations) to give POTWsgreater control of hazardousconstituents entering their treatment andcollection systems.

4. Enforcement of Categorical Standards

The Study recommended that-EPAimplement stringent enforcement ofcategorical pretreatment standards.Such enforcement would cause asignificant reduction of pollutantloadings to POTWs, particularly ofheavy metals. More stringentenforcement of the standards was also -

recommended recently by thePretreatment Implementation ReviewTask Force (PIRT) which last year gavethe Agency recommendations forimproving the national pretreatmentprogram.

A series of audits performed by EPAof pretreatment programs at manymunicipalities has revealed that there isconsiderable room for improvement incompliance by industry with thecategorical standards. One way toaddress the problem is through therelevant PIRT recommendations. Inaccordance with thoserecommendations, EPA has preparedguidance on compliance monitoring andenforcement for POTWs. This guidancewill help POTWs set priorities for theirlocal enforcement programs byproviding 'definitions of "significant"industrial users and "significant"noncompliance. The guidance will alsorecommend monitoring frequencies forindustrial users and provide guidance onthe semi-annual reports required ofindustrial users.

The Agency is also conducting auditsof all approved local pretreatmentprograms over a five-year period, aswell as conducting pretreatment

compliance inspections at POTWs oncea year. EPA Regions and States willensure that compliance is achieved byreviewing annual reports, conductingaudits and inspections, ensuring publicnotice of violations, and, whereappropriate, enforcing against industrialusers. EPA has already filed manyenforcement actions against violationsof the pretreatment standards. However,the Agency's enforcement efforts areonly one portion of the total effortenvisioned by Congress. ImprovedPOTW pretreatment programs areessential to the implementation andenforcement of pretreatmentrequirements.

The Agency will provide assistanceand advice to POTWs experiencingdifficulty in the early stages of localpretreatment program implementation.To this end, EPA plans to developguidance on what constitutes properimplementation of a local program. Theguidance would indicate thecircumstances under which EPA wouldtake action against a POTW forunacceptable performance. In addition,EPA Regions and States will establishan inventory of industrial users in areaswhere there is no local program and willestablish control mechanisms for theseusers, as well as initiating enforcementactions where necessary.

EPA also intends to complete existingenforcement cases against any POTWswith unapproved local programs andwill initiate new enforcement actionsagainst POTWs that fail to implementapproved programs.

The Agency has also recentlyproposed amendments to the generalpretreatment regulations which wouldclarify and expand the requirementsapplicable to industrial users for self-monitoring (see 51 FR 21454, June 12,1986). These amendments will help bothPOTWs and industrial users to becomeaware if categorical standards havebeen violated and to take theappropriate remedial or enforcementmeasures.

Industrial users must currently submitto the Control Authority (i.e., the POTW,the State, or EPA) a baseline monitoringreport containing basic information onthe user's discharge and compliancestatus (this report must be submittedwithin 180 days after the effective dateof the applicable categorical standard).Industrial users must also submit apreliminary report on compliance withcategorical pretreatment standards (tobe submitted within 90 days of thedeadline for compliance with theapplicable standard) and subsequentperiodic reports on compliance with thestandards (to be submitted twice

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yearly). The proposed amendmentswould clarify that the periodiccompliance reports must be based on anappropriate amount of sampling andanalysis (to be determined by thePOTW) performed during the reportingperiod. The amendments also propose torequire that industrial users report theresults of sampling and analysis iftheseresults indicate that a violation hasoccurred (this report must be submittedwithin three weeks of the apparentviolation). The proposed amendmentswould further require industrial users toinform the Control Authority of anysubstantial changes in the volume orcharacter of.pollutants in the user'sdischarge. However, they would clarifythat the Control Authority may elect toconduct its own monitoring program inlieu of relying solely on self-monitoringby its industrial users. Finally, theproposed amendments require theControl Authority to impose appropriatereporting requirements for pollutants notregulated by categorical standards.

EPA believes that these proposedchanges, when promulgated, willsubstantially improve POTWs' ability toenforce compliance with categoricalpretreatment standards. The Agencysolicits comments on any additionalways to ensure that these standards areenforced to the fullest extent possible.

5. Local LimitsThe Study recommended that local

limits be improved and fullyimplemented at POTWs to controldischarges of organic pollutants andother hazardous wastes.

Under the general pretreatmentregulations (40 CFR 403.5(c)), POTWsadministering local pretreatmentprograms must develop and enforcelocal limits to implement the general andspecific prohibitions discussed above.All other POTWs must develop specificeffluent limits if pollutants contributedby industrial users have resulted ininstances of pass through or interferencethat are likely to recur.

Local limit-setting offers highpotential for improved control ofhazardous waste discharges. Efforts byPOTWs to establish local limits havebeen successful in the case of toxicmetals (cadmium, chromium, copper,lead, nickel, and zinc) which arefrequently found in the sludges, theeffluent, and the influent at POTWs. InAugust 1985, EPA Headquarters issuedinterpretive guidance to EPA Regionsand States that clarified EPA's minimumlocal limits requirements for POTWs,especially the requirements for locallimits on the metals mentioned above.Additional technical guidance isavailable in EPA's Guidance Manualfor

Pretreatment Program Development(October 1983).

Nevertheless, much work remains tobe done to develop local limits for otherhazardous constituents, especiallyorganic solvents and other organicconstituents. It is particularly importantthat these limits be derived from asound technical analysis of interferenceand pass through concerns, so that therequirements of the CWA prohibitinginterference and pass through will bemore readily enforceable throughspecific, verifiable numeric effluentlimits.

Issuing guidance in certain areasmight be useful in helping POTWs todevelop effective and enforceable locallimits. For example, the Agency couldissue guidance on limit-settingmethodologies that emphasize passthrough or interference concerns,although this is a technically difficultproblem which may be best approachedby issuing guidance in several steps,beginning with those constituents thatare best understood. Likewise, theAgency could provide guidance andinformation on available technologiesfor use by POTWs in setting limitsbased on best professional judgment.EPA is now preparing such guidance,which will include advice on the use oftoxicity testing to help POTWs setpriorities for local limits by identifyingdischarges of particular concern.

In addition, the Agency mightconsider amending the generalpretreatment regulations to requirePOTWs to use a permit system as thebasis of their pretreatment programs,unless the POTW could demonstrate anadequate alternative approach. Such asystem would involve a writtendocument such as a permit that wouldreflect a binding agreement between thePOTW and the industrial userconcerning effluent limitations andmonitoring frequency. Such a document,besides being a useful enforcement tool,could serve as a convenient mechanismfor POTWs to develop local limitsapplicable to all industrial users.Although the Agency has not heretoforerequired POTWs to adopt such anapproach, it is possible that manypretreatment programs would benefitfrom it.

As mentioned above, EPA alsointends to propose modifying theregulations relating to pass through andinterference to require that local limitsbe established for hazardousconstituents in the absence of NPDESpermit limits for these pollutants (for afurther discussion of this issue, see PartIV.A.1 above).

EPA solicits comments on these andother ways to help POTWs set specificlimits to control hazardous constituents.

B. Categorical Pretreatment Standards

One of the main recommendations ofthe Study was that EPA review andamend categorical pretreatmentstandards to achieve better control ofthe constituents of hazardous wastes.The Study recommended that theAgency modify existing standards toimprove control of organic prioritypollutants and non-priority pollutants,and that EPA promulgate categoricalstandards for industrial categories notincluded in the Natural ResourcesDefense Council consent decree (NRDCv. Train, 8 ERC 2120, D.C.C. 1976). Aspart of the effort of developing newcategorical standards and amendingexisting standards, the Study alsorecommended that the Agency evaluatesources of solvents listed as hazardouswastes under RCRA that are dischargedto POTWs and develop sampling andanalytical protocols for nonpriority,pollutants. In addition, the Studyrecommended that EPA considerincluding selected RCRA constituents onthe CWA priority pollutant list, oradopting an equivalent approach forregulating these constituents.

Categorical pretreatment standardsare an important means of reducingtoxic loadings to the nation's sewers.EPA has made considerable progress inpromulgating these national standards.Currently, categorical pretreatmentstandards for existing sources whichinclude discharge limits for toxicpollutants apply to 23 specific industrialcategories.-The Study estimated thatroughly 14,000 indirect dischargers aresubject to categorical pretreatmentstandards, including such majorcontributors of industrial wastes asmetal finishers, manufacturers ofpesticides, and iron and steelmanufacturers. Full compliance with thestandards will result in a significantreduction in toxic loadings to POTWs.

The effluent guidelines rulemakingsfor these standards have concentratedon the control of the 126 compounds onthe CWA priority pollutant list. Becauseheavy metals (e.g., lead, cadmium,nickel) are well represented on this list,the Study found that full compliancewith existing categorical standardsshould significantly reduce loadings toPOTWs of metal constituents such asthose discharged by the metal finishing,battery manufacturing leather tanningand inorganic chemicals industries.

However, the Study predicted thatimplementing the standards would notreduce loadings of organic pollutants to

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the same extent. The Study found thatsignificant organics sources (e.g.,pharmaceutical manufacturers,laundries, equipment manufacturing,wood refinishing, petroleum refining) arelargely unregulated for these pollutantsunder existing categorical pretreatmentstandards.

Moreover, by authority of paragraph 8of the NRDC consent decree, EPAdetermined that national categoricalstandards for all or part of twelve otherindustrial categories (including paintformulation, printing and publishing,and auto and other industrial laundries)were not necessary. Sources in thesecategories are still subject to theprohibited discharge standards of thegeneral pretreatment regulations andmay also be specifically regulated bylocal POTW ordinances, including locallimits.

After considering the scope of theNRDC consent decree and the extent ofparagraph 8 exemptions, the Studyfound that potential industrial sources ofhazardous waste discharges to POTWsmay not be sufficiently regulated bycategorical standards. Theseunregulated sources include emergingindustries [e.g., hazardous wastetreatment and solvent and oil recovery)that are not addressed in the consentdecree, and service-oriented industries(such as industrial laundries andhospitals) that tend to discharge smallerquantities of toxic pollutants on afacility-specific basis.

In addition, EPA has identified threeother unregulated industrial categoriesas potential candidates for regulatoryaction to control discharges of toxic andhazardous pollutants. These areferroalloy manufacturing, hot dipcoating, and textiles.

In response to the recommendationsof the Study, EPA has begun to collectadditional data from twelve regulatedand unregulated industries to determinewhich warrant national regulation. Theunregulated industries are hazardouswaste treaters (including centralizedwaste treaters), solvent reclaimers,barrel reclaimers, waste oil reclaimers,equipment manufacturers andrebuilders, paint manufacturers,transportation, industrial laundries, andhospitals. The regulated industries aretextiles, timber, and pharmaceuticals.The data collection efforts consist ofworkplan development, characterizationof the industry, sampling and analysis,wastestream characterization,determination of wastewatertreatability, and environmental impactanalyses. Wastestream sampling andanalysis will be initiated for most of thetwelve industries in FY 1986.Wastewater and sludges from five

municipal wastewater treatmentfacilities will also be collected andanalyzed.

The Agency will use the informationcollected through these efforts todevelop decision documents, which willeventually be published for all theindustries discussed above (beginningwith hazardous waste treaters, solventreclaimers, and pharmaceuticals in FY1987). These decision documents willprovide a technical basis to determinewhether a regulation should bedeveloped for a particular industry, andwill also serve as a summary ofinformation to be used by permit writersand POTWs in controlling hazardouswastes until final rules are published.

In response to the Study'srecommendations concerning evaluationof solvents and development ofsampling and analytical protocols, EPAhas already begun to develop analyticaltechniques for the measurement ofhazardous waste constituents, using GasChromatography/Mass Spectroscopymethods with new extractionprocedures, standards for newcompounds, new response timeinformation, and spectra identificationinformation. The Agency will use thesetechniques to evaluate industrialwastewaters for the presence ofheretofore unmeasured pollutants inthese wastewaters, including hazardousconstituents which are also non-prioritypollutants under the CWA. As part ofthis effort, EPA will be analyzingindustrial and municipal wastewatersfor over 350 chemicals in 1986.

EPA solicits comments on these and'other ways to improve categoricalpretreatment standards to achievebetter control of hazardous constituentsdischarged to POTWs.

C. Water Quality Issues and SludgeControl

1. Issuance of Water Quality Criteria;Water Quality-Based Permitting

The Study recommended that EPAdevelop additional water quality criteriafor constituents of RCRA hazardouswaste, particularly pollutants that arenot listed as priority pollutants underthe CWA. The Study furtherrecommended that the Agency expandthe use of biomonitoring techniques andwater quality-based permitting toimprove protection of receiving waters.Expedited issuance of water qualitystandards was also recommended byPIRT.

Under section 303 of the CWA, waterquality standards are developed byStates, based either on federal waterquality criteria or site specifically-derived criteria. The standards are

meant to protect certain uses forreceiving waters, such as fishing,swimming, water supply, or industrialuse. Using wasteload allocationtechniques, these water quality-basedpollutant standards, in turn, aretranslated into effluent limits needed toprotect water quality and designateduses pursuant to sections 301 and 302 ofthe CWA. The standards are also usedby POTWs in developing local limits forindustrial users to prevent pass throughof pollutants which would cause aviolation of the water quality-basedlimits of the POTW's NPDES permit (see40 CFR 403.3(n), currently suspended).Guidance on the application of waterquality criteria and standards and ongeneral water quality-based toxicscontrol is available in the Agency'sTechnical Support Document for WaterQuality-Based Toxics Control(September, 1985).

The Agency has published waterquality criteria documents for manyorganic pollutants, including somehazardous constituents evaluated in theStudy. These pollutants includebenzene, chlorinated benzenes, phenols,and toluene (for copies of the completedocuments for individual pollutants,contact the National TechnicalInformation Service [NTIS], 5285 PortRoyal Road, Springfield, Virginia 22161).The Agency is presently developingcriteria for some additional RCRAconstituents (particularly organicpollutants, including solvents) whichwill help States to implement morewater quality standards.

In addition, the Agency is conductingother activities to improve receivingwater quality as part of its third roundpermits strategy. For example, everyState and territory now has a waterquality standard requiring thatdischarges must be free from toxicpollutants in toxic amounts. Using thechemical-specific and biologicalapproaches presented in the TechnicalSupport Document, EPA plans toencourage permitting authorities toimplement these "free from" waterquality standards more aggressively inpermits to help ensure that hazardousconstituents are not discharged fromPOTWs in toxic amounts. As part of thiseffort, EPA has begun working with theStates to develop a list of waters forwhich technology-based requirementsare not sufficient to protect waterquality standards. The Agency's targetis for States to develop needed waterquality-based controls for twentypercent or more of the waters on the listby September 1987.

The Agency also plans to prepare amethodology for screening chemicals

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not specifically covered by regulationspromulgated by EPA to date under theClean Water Act. This methodologywould include scientific analysis of theparticular chemical, review of toxicityinformation and ambient levels,treatability analysis, determination ofwhether the chemical is likely to beremoved by technology-basedtreatment, and a decision about theneed for a water quality criterion.Completing and implementing thismethodology will continue over severalyears.

The Agency solicits suggestions onthese and other ways to improve thestate of water quality-based programs.

2. Sludge Criteria for RCRA HazardousWastes; Criteria for the Use andDisposal of Sewage Sludge

The Study recommended that EPAdevelop sewage sludge criteria forRCRA hazardous constituents, as wellas criteria for the use and disposal ofsewage sludge. These criteria will helpPOTWs set local limits to preventinterference with their sludge disposaloptions (see 40 CFR Part 403.3(i),currently suspended). PIRT alsorecommended that sludge managementand disposal requirements be developedas soon as possible.

Section 405 of the CWA requires EPAto develop regulations providingguidelines for the use and disposal ofmunicipal sludge. These regulationsmust identify sludge use and disposaloptions, specify factors to be consideredin determining the practices applicableto each option, and identifyconcentrations of pollutants thatinterfere with each option. To date,regulations defining acceptable landdisposal practices (40 CFR Part 257)have been promulgated under the jointauthority of section 405 of the CWA andSubtitle D of RCRA which establishgeneral requirements for the landfilling,and land application of sludge and setmaximum contaminant levels forcadmium and polychlorinated biphenyls(PCBs). Other laws, such as the CleanAir Act (CAA), RCRA Subtitle C, andthe Toxic Substances Control Act(TSCA) also govern municipal sludgeuse or disposal, depending on thedisposal option employed or theconstituents and their levels present inthe sludge.

EPA is currently preparingcomprehensive sludge managementregulations under the authority ofsection 405 of the CWA. This initiativehas two parts. The first is programmatic:regulations have been proposed(February 4, 1986; 51 FR 4458) whichdelineate the roles of Federal and Stategovernments in sludge management and

which set forth the minimum criteria forstate sludge management programs. Thesecond part is technical: the Agencyplans to propose and promulgate in twophases (the first phase is due to bepromulgated in 1987) technicalregulations addressing certainconstituents in sludges managed bydifferent practices (distribution andmarketing, ocean dumping, landfilling,land application, and incineration). As afirst step towards promulgating thetechnical sludge criteria, EPA hasalready developed a list ofapproximately 41 pollutants to beconsidered for regulation. many ofwhich are RCRA constituents. TheAgency plans to continue research onadditional constituents of hazardouswaste to be included in the secondphase criteria. Promulgating thesetechnical regulations for the use and

* disposal of sewage sludge shouldalleviate sludge management problemsoccasioned by the discharge ofhazardous constituents to POTWs.

The Agency solicits comments onthese and other ways to improve thequality and management of municipalsewage sludge. Comments concerningthe specific proposed rules on stateprogram requirements and technicalcriteria should be submitted in thecontext of those rulemakings.

D. Research and Data Collection

In addition to recommendingregulatory and program changes toimprove control of hazardousconstituents, the Study recommendedcertain research and data collectionefforts to fill information gaps on thesources and quantities of hazardouswastes and their fates and effects inPOTW systems and the environment.The results of these efforts can then beused to design any additional controlswhich might prove necessary. If therecommended research indicates thepresence of problems, RCRA, theComprehensive EnvironmentalResponse, Compensation, and LiabilityAct (CERCLA) and the Clean Air Act(CAA) may be considered along withthe CWA to control hazardousconstituents and/or receiving POTWs.

EPA has already begun two of theresearch efforts recommended by theStudy (development and refinement ofsampling and analytical protocols fornon-priority pollutants, and evaluationof RCRA solvents discharged toPOTWs) as part of the process ofmodifying the categorical pretreatmentstandards as discussed above. Anotherresearch effort (assessment of midnightdumping into sewers) is discussed inPart IV-A-2 above. The remainingrecommendations of the Study

concerning research and data collectionare discussed below.

1. General Pollutant Fate and Effects

The Study recommended that theAgency continue research on pollutantfate within POTW collection andtreatment systems, includingexamination of the effects of biologicalacclimation on POTW removalefficiencies and pollutant fate. TheStudy also recommended continuedresearch concerning the effects onhuman health and the environment ofthe discharge of hazardous wastes toPOTWs.

The Study identified four significantpollutant fates within POTW treatmentsystems: air stripping, adsorption tosludge, biodegradation, and passthrough to receiving waters. The firstthree of these constitute "removal" of.pollutants from wastewaters; however,air stripping and adsorption do notnecessarily destroy the pollutant andmay result in adverse environmentalimpacts. Based on laboratory studies,the Study estimated that 92 percent ofthe pollutants identified in the Study areremoved by a fully acclimatedbiological treatment system beforedischarge to surface waters. Assumingan unacclimated biological treatmentsystem at a POTW, an estimated 82percent of the pollutants identified in theStudy are removed before discharge tosurface waters. Of course, the actualremovals at any site will depend uponthe quality of the influent and can varyfrom little removal to substantialremoval. In addition, as indicated bythese projections, the degree ofbiological acclimation in POTWtreatment units may significantly affectPOTW.removal efficiencies. The Agencyneeds additional information onwastewater discharge patterns andbiological acclimation rates at POTWsbefore it can determine the importanceof the individual fate mechanisms andthe potential for adverse environmentalimpacts.

As an additional caveat, the Studyalso found that significant effects onwater quality and sludge are caused asmuch by toxicity and othercharacteristics of the pollutantsdischarged, as by the mere quantities ofthese pollutants entering theenvironment. Water quality analysesand bioassays conducted by EPA'sOffice of Research and Development,EPA Regions, and States indicate thatPOTW effluent discharges frequentlyexhibit adverse water quality impactswhen measured in terms of toxicity. Theresults of these studies depend on theparticular methodology used and the

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circumstances present at each site.There is no general study on the fateand effects of hazardous constituentsdischarged to POTWs. Therefore,research should be continued to learnmore about the causes of toxicity,including hazardous constituents andnon-priority pollutants.

EPA intends to continue its researchon the fates and effects of hazardouswastes discharged to POTWs. In themeantime, the Agency solicits commentson these and other ways to improve itsknowledge in this area.

2. Air EmissionsThe Study recommended collecting

data on emissions of volatile organiccompounds (VOCs) and otherpotentially toxic air pollutants fromPOTWs, as well as developing andrefining techniques for monitoring airreleases at POTWs.

Air emissions from POTWs mayemanate from collection and treatmentsystems in several ways. Organiccompounds contained in the dischargesfrom industrial users may volatilize bothen route to the POTW and at the POTWitself. These pollutants are emitted asgases to both the ambient air and theworkplace (POTW) environment. Inaddition, the incineration of sewagesludge may emit to the ambient airhazardous constituents (especiallyVOCs and metals) which have beenadsorbed to the sludge during treatment.Both volatilization and incineration mayaffect worker health and safety andambient air quality. Worker health andsafety might be affected by theincreased potential for explosions due tovolatile constituents in the wastestream,and by acute and chronic health effectsdue to contact with volatilizedpollutants.

With respect to ambient air quality,EPA estimates that at least 12 millionkilograms per year of VOCs are emittedby POTWs to ambient air. POTWemission of VOCs is predicted bymathematical models and has beenconfirmed by EPA through ambientmonitoring at Philadelphia,Pennsylvania as well as in laboratorytests. However, a more thoroughevaluation of the health effects of theseand other volatile pollutants ishampered substantially by difficulties inmeasuring emissions from POTWs,limited understanding of pollutant fatein ambient air, lack of exposureassessments, and lack of hurflan healthcriteria for exposure to toxics in theambient air environment. In addition,more information is needed on the effectof incineration of contaminatedmunicipal sludges on air quality. To thisend, the Agency is preparing a risk

assessment methodology which willimprove its knowledge of the'environmental impacts of sludgeincineration.

The Study recommended that EPAconduct further study of air emissionsfrom POTWs before developingregulatory or other strategies to dealwith the problems. Strengthening thegeneral pretreatment program asdiscussed in Parts A and B below shouldresult in improvement of the quality ofsuch emissions. In addition (dependingon the results of the recommendedresearch), the Agency may considerexpanding the regulation of VOCs underthe CAA. For example, emission limitsmight be established for VOCs fromsewers and POTWs (on a State-by-Statebasis using State Implementation Plansor by means of permits for non-attainment areas) in order to meet theNational Ambient Air Quality Standardsestablished under section 109 of theCAA. In addition, the NationalEmissions Standards for Hazardous AirPollutants (NESHAPS) under section 112of the CAA might also be used to controlair releases of hazardous wastes.Section 112 of the CAA also provides forimposition of management practices thatcould be employed to keep volatilematerials out of the system before theycan pose a problem.

Alternatively, EPA might considerregulating air emissions from POTWsreceiving hazardous wastes undersection 3004(n) of RCRA, which requiresthe Agency to promulgate regulations forthe monitoring and control of airemissions at RCRA treatment, storage,and disposal facilities (TSDFs). Such anaction would require modifying theDomestic Sewage Exclusion. Otherpossible RCRA regulatory mechanismsfor the control of air emissions aresection 3004(m), which requires EPA topromulgate treatment standards forwastes subject to the land disposal ban,and section 3005(c), which enables theAgency to add site-specific conditions toRCRA permits as necessary to protecthuman health and the environment.

EPA solicits comments on these andother ways to improve control ofhazardous constituents discharged tothe ambient air from POTW treatmentand collection systems.3. Groundwater Contamination

The Study recommended that EPAassess possible sources of groundwatercontamination from POTWs, includingexfiltration (leakage) from sewers andcontamination due to leachates fromlandfills which handle sewage sludges.

At the present time, the Agency doesnot know whether leaks from POTWsewer systems have caused

groundwater contamination. There areseveral theoretically possible pathwaysfor the contamination of groundwater bythe discharge of hazardous wastes toPOTWs, including exfiltration fromsewers, leaks from wastewatertreatment units, land application ofmunicipal sludge (land filling and landspreading), wastewater treatmentlagoons, land treatment of municipalwastewater, and deep well injection.

Of these pathways, the Study singledout exfiltration from sewers as mostdeserving of further study (because ofcurrent lack of knowledge on the subjectrather than because contamination fromthis pathway seemed likely). Municipalsludge disposal and land treatment arealready regulated and underconsideration for further regulation.With respect to wastewater treatmentlagoons, the Agency is conducting astudy under the authority of section3018(c) of the HSWA of 1984 todetermine the impact of these lagoonson groundwater contamination. Thisstudy is due to be completed in thespring of 1987. Concerning deep wellinjection, the Study estimated that fewerthan 100 POTWs use this method ofwaste disposal. The Study assumed thatinjection would in any event produceminimal groundwater impacts becauseof its regulation under the Safe DrinkingWater Act. Therefore, compared toother pathways to contaminationdiscussed by the Study, exfiltration togroundwater from sewers seemed to bethe most likely candidate for futureresearch.

After study is completed on the effects(if any) of groundwater contaminationresulting from hazardous constituentsdischarged to POTWs, the Agency willconsider regulatory or programstrategies to control such contamination.In the meantime, EPA solicits commentson ways to improve its knowledge aboutgroundwater contamination caused bythe discharge of hazardous wastes toPOTWs.

V. Related Issues

Section 3018(a) and the Study are bothconcerned with the results of theDomestic Sewage Exclusion of RCRA.Since today's notice is intended by EPAto address the specific recommendationsof the Study, it does not discuss allrelated issues concerning hazardous andother wastes received by POTWs. Theseperipheral issues include theinterpretation of RCRA corrective actionrequirements, the RCRA mixture rule forthe definition of hazardous waste, andthe dimensions of the RCRA "permit byrule." Other issues include theapplication of RCRA financial

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responsibility requirements (includingthe closure and financial assuranceprovisions for hazardous wastemanagement), the disposal of wastes toPOTWs from CERCLA sites, the role ofquantitative risk assessment inprotecting human health and theenvironment, and the relation of futureregulatory actions to current RCRAdelegation to States. EPA is nowseparately examining these relatedconcerns, and plans to issue policiesand propose regulatory changes asappropriate in the future.

In addition, the Agency wishes topoint out that, according to the Study,approximately half of all hazardouswastes studied in four organic chemicalsindustries are treated and dischargeddirectly to surface waters underNational Pollutant DischargeElimination System [NPDES) permits.Such wastes are not deemed hazardousunder RCRA section 1004(27) (see 40CFR 261.4(a)(2)). Although this ANPR

addresses mainly hazardous wastedisposal to POTWs, the Agency is alsointerested in receiving comments aboutthe implications of this finding for theNPDES permit program.

VI. Regulatory Impact AnalysisExecutive Order 12291 requires that a

regulatory impact analysis (RIA) beconducted if certain criteria are met,such as an annual economic impact of aregulation totaling $100 million. Becauseno regulatory amendments are proposedin today's notice, EPA has not yetevaluated whether or not an RIA isnecessary. When formal proposals aredeveloped for publication, the Agencywill reconsider the question of thenecessity for an RIA.

VII. Regulatory Flexibility AnalysisThe Regulatory Flexibility Act of 1980

(RFAJ requires an analysis of anysignificant economic impact of proposedand final regulations on small entities.

Because the Agency is proposing noregulatory amendments in today'snotice, we have not developed an RFAanalysis. When EPA develops formalproposals for publication pursuant to,today's notice, we will reconsiderwhether or not to develop an RFAanalysis.

VIII. Paperwork Reduction Act

Today's notice contains no formalproposals for regulatory amendmentsand therefore contains no informationcollection requirements which must bereviewed by OMB under Section 3504(h)of the Paperwork Reduction Act of 1980.These requirements will be submittedfor review at the time the Agency makesa decision on proposals for publication.Lee M. Thomas,Administrator.August 14, 1986.[FR Doc. 86-18984 Filed 8-21-86; 8:45 am]BILLING CODE 6560-50-M

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