environmental protection agency€¦ · proposal, major supporting documents, and a copy of the...

WednesdayJuly 8, 1987

Part II

EnvironmentalProtection Agency40 CFR Parts 141 and 142National Primary Drinking WaterRegulations-Synthetic OrganicChemicals; Monitoring for UnregulatedContaminants; Final Rule

25690 Federal Register / Vol. 52, No. 130 / Wednesday, July 8, 1987 / Rules and Regulations

ENVIRONMENTAL PROTECTIONAGENCY

40 CFR Parts 141 and 142

[WH-FRL-3213-8]

National Primary Drinking WaterRegulations; Synthetic OrganicChemicals; Monitoring for UnregulatedContaminants

AGENCY: Environmental ProtectionAgency (EPA).ACTION: Final Rule.

SUMMARY: In this notice, EPA ispromulgating National Primary DrinkingWater Regulations (NPDWRs) forcertain volatile synthetic organicchemicals (VOCs). Specifically, thisnotice promulgates maximumcontaminant levels (MCLs) for:Trichloroethylene, carbon tetrachloride,1,1,1-trichloroethane, vinyl chloride, 1,2-dichloroethane, benzene, 1.1-dichloroethylene, and para-dichlorobenzene. The NPDWRs alsoinclude monitoring, reporting and publicnotification requirements for these eightVOCs. EPA is also publishing themaximum contaminant level goal(MCLG) for para-dichlorobenzene. Thisnotice specifies the best availabletechnology (BAT) upon which the MCLsare based and BAT for the purpose ofissuing variances. In this notice, theAgency is also promulgating proceduresby which systems may obtain variancesand exemptions from these NPDWRs. Inaddition to the NPDWRs for the eightVOCs, the Agency is also promulgatingmonitoring requirements for 51 othersynthetic organic chemicals which arenot regulated by NPDWRs.

EPA proposed NPDWRs, includingMCLs, for the eight VOCs listed aboveon November 13, 1985 (50 FR 46902).New data on the toxicology of para-dichlorobenzene became available afterthe November 13 notice which changedits health effects classification. EPAproposed to amend the MCLG andreproposed the MCL for thiscontaminant on April 17, 1987 (52 FR12876), based on this new information.EFFECTIVE DATES: This regulation iseffective January 9, 1989, except for§ § 141.24(g), 141.35, and 141.40. Theinformation collection requirements in40 CFR 141.24(g), 141.35, and 141.40 areeffective January 1, 1988, if theinformation collection request is clearby the Office of Management andBudget (OMB) and an OMB clearancenumber is assigned prior to that date. Ifnot, the requirements will be effectivewhen OMB clears the request and anotice is published. In accordance with

40 CFR 23.7, this regulation shall beconsidered final agency action for thepurposes of judicial review at 1:00 pmeastern daylight savings time on July 22,1987.ADDRESSES: Public comments on theproposal, major supporting documents,and a copy of the index to the publicdocket for this rulemaking are availablefor review during normal business hoursat the EPA, Room 2904 (rear) in thePublic Information Reference Unit, 401M Street, SW., Washington, DC 20460. Acomplete copy of the public docket isavailable for inspection at EPA inWashington, DC by appointment bycontacting Ms. Colleen Campbell 202/382-3027.FOR FURTHER INFORMATION CONTACT:Joseph A. Cotruvo, Ph.D., Director,Criteria and Standards Division, Officeof Drinking Water (WH-550), U.S.Environmental Protection Agency, 401 MStreet, SW., Washington, DC 20460, 202/382-7575, or one of the EPA RegionalOffice contacts listed in "SupplementryInformation". Information may also beobtained from the EPA Drinking WaterHotline. The toll-free number is 800/426-4791 and the Washington, DC number is382-5533.SUPPLEMENTARY INFORMATION:

EPA Regional OfficesI. JFK Federal Bldg., Room 2203, Boston,

MA 02203, Phone: (617) 565-3610,Jerome Healey

II. 26 Federal Plaza, Room 824, NewYork, NY 10278, Phone: (212) 264-1800,Walter Andrews

I1. 841 Chestnut Street, Philadelphia, PA19107, Phone: (215) 597-9873, JonCapacasa

IV. 345 Courtland Street, Atlanta, GA30365, Phone: (404) 347-2913, WilliamPatton

V. 230 S. Dearborn Street, Chicago, IL60604, Phone: (312) 353-2650, JosephHarrison

VI. 1445 Ross Avenue, Dallas, TX 75202,Phone: (214) 655-7155, Thomas Love

VII. 726 Minnesota Ave., Kansas City,KS 66101, Phone: (913) 236-2815,Gerald R. Foree

VIII. One Denver Place, 999 18th Street,Suite 300, Denver, CO 80202-2413,Phone: (303) 293-1424, Marc Alston

IX. 215 Fremont Street, San Francisco,CA 94105, Phone: (415) 974-0763,William Thurston

X. 1200 Sixth Avenue, Seattle, WA98101, Phone: (206) 442-4092, RichardThiel

Abbreviations Used in This Notice

BAT: Best Available TechnologyBTGA: Best Technology Generally

Available

CWS: Community Water SystemEMSL: EPA Environmental Monitoring

and Support Laboratory (Cincinnati)GAC: Granular Activated CarbonLOQ: Limit of QuantitationMCL: Maximum Contaminant Level

(expressed as mg/l)*MCLG: Maximum Contaminant Level

GoalMDL: Method Detection Limitmgd: Million Gallons per DayNIPDWR: National Interim Primary

Drinking Water RegulationNPDWR: National Primary Drinking

Water RegulationNTNCWS: Non-transient Non-

community Water Systemp-dcb: para-DichlorobenzenePOE: Point-of-Entry TechnologiesPOU: Point-of-Use TechnologiesPQL: Practical Quantitation LevelPTA: Packed Tower AerationPWS: Public Water SystemPWSS: Public Water System SupervisionRMCL: Recommended Maximum

Contaminant LevelSDWA: Safe Drinking Water Act, or the

"Act," as amended in 1986THMs: TrihalomethanesURTH: Unreasonable Risk to HealthVOC: Volatile Synthetic Organic

Chemical"1.000 micrograms (ug) = 1 milligram (mg)

Table of Contents1. Summary of Today's ActionsII. Background

A. Statutory AuthorityB. Regulatory BackgroundC. Public Comments on the Proposal

III. Explanation of Today's ActionsA. Non-transient Non-community Water

SystemB. MCLG for para-dichlorobenzeneC. MCLs for VOCs1. Treatment Technologies2. Costs3. Other Factors4. Summary of MCL Determinations

D. Other Treatment TechnologiesE. Analytical Methods and Compliance

Monitoring Requirements1. Analytical methods2. Compliance Monitoring Requirements

F. Laboratory ApprovalG. Variances and Exemptions1. Variances2. Exemptions3. Central Treatment vs. POU/BottledWater

H. Public NotificationI. Reporting RequirementsJ. Total Volatile Synthetic Organic

Chemicals (TVOC)K. Monitoring for Unregulated

ContaminantsIV. Effective DatesV. Impact AnalysesVI. References and Public Docket

:Federal :Register ;/'V61. 52. No. 1-30 ,/ Wednesday, Jtily 8, .1987 / Rules 'and AReguilations

List of TablesTable 1-Final MCLGs and Proposed-and

Final MCLs for the VOCsTable 2-An Example of.Lipper Bound

Lifetime Cancer;Risk (10-!) Estimates forVOCs Categorized as.Known or ProbableHuman Carcinogens

Table 3-Schedule 6 Repeat MoiitoringRequirements

Table 4-Analyses within- the AcceptanceLimits of Eleven VOC Samples

Table 5-EstimatedCosts-of Removing -VOCsfrom Drinking Water Using PackedTower Aeration or Granular ActivatedCarbon for the Smallest System Size

Table 6-Unregulated ConlaminantsTable 7-Costs ($ million/year%) for

'Monitoring for Compliance.with'MCLsfor VOCs and for Unregulated'VOCs.

I. Summary of Today's Action

Applicability

The requirements of this notice applyto all community water systems. [CWS)and non-transient non-community watersystems (NTNCWS).

Non-transient non-community watersystems are those which regulaly servethe same 25 ormore,persons at least*6months per year.

Final MCLG:

para-dichlorobenzene---&.075 mg/I

Final MCLs:

1. benzene-0.005 mg/l2. carbon tetrachloride---0.005 mg/I3.1, 2-dichloroethane--O.005 mg/l4. trichloroethylene--.0.005 mg/l5. para-dichlorobenzene--o,075 mg/l6. 1,1-dichloroethylene--0.007 mg/l7. r,1-,1trichloroethane--020 mg/l8. vinyl chloride-0.002 mg/l

BAT under Section 1412-of the SDWA(MCLs):

Packed tower aeration (PTA) orgranular activated carbon (GAC) for- allregulated VOCs, except vinyl chloride.

PTA for vinyl chloride.Other effective removal technologies

that treat all of the drinking water:in apublic supply although not designatedBAT may also be applied toachievecompliance.

BAT under Section 1415 (Variances):

Same technologies are BAT as thoseunder Section 1412.

Monitoring Requirements andCompliance Determination

The basic monitoring requirementsare as follows:

Quarterly samples Tor each.groundand surface water source.

Composite samples of up to fivesources are allowed.

Monitoring requirements are phasedin by system size (i.e.,populationserved)

Popuaimseved -Monftoring awst. begat by

> 0.0 00 ................. -- Jan.1 88.3,300-10 ,000 ........................ I Jan. 1,1989.< 3.300 ....................................... 'Jan. 1, 991

Determination. 6f compliance isestablishedas~follows: Both-ground andsurface.water~systems must calculate, arunning average of the concentration..ofeach VOC,:over one year, taking at leastone sample,per. quarter, for each source.

All samples~must be used.For, groundwaters,. the Stateas

primacy.agent may reducethe.samplingfreguency if-regulated VOCs-are.notdetected-in the first -sample. Theminimum possible-monitoringrequirement, for compliance is onesample. per-source.

Repeat, monitoring -varies Lfromquarterlylto once per fiveyears.Statesdeterminei repeat, monitoringrequirements,based on::(1) Whether ornot VOCshavebeen detected, in theinitial sampling,, and (.2) .the vulnerabilityof. the system, to: contamination(determinediby the State).

Analyticdl.Methods:

1. EPA Method 502.1-VolatileHalogenatedlOrganic CompoundsiinWaterbyPurge' and Trap GasChromatography.

.2. EPAMethod. 502.2-VolatileOrganic'Compounds-in Water by Purgeand Trap Gas ChromatographytwithPhotoionization and'ElectrolyticConductors in Series.

3. EPA Method 503.1-VolatileAromatic and Unsaturated-OrganicCompounds in Water by Purge and TrapGas Chromatography.

4. EPAMethod 504--14,2-Dibromoethane and 1;2-Dibromo-3-chloropropane in WaterbyMicroextraction. and Gas'Chromatography.

5. EPA Method 524.1-VolatileOrganic'Compounds in-Water by Purgeand Trap Gas'Chromatography/MassSpectrometry.

6. EPA'Method 524;2-VolatileOrganic Compounds in'Water by Purgeand Trap Capillary Column GasChromatogrEphy/Mass-Spectrometry.

Laboratory' Gertification:CrtteriaVinyl Chloride:

±-'40 percent at any concentrationAll others:

± 20 percent. 0.010 mg/l- 40,percent <0.010.mg/l

Point-of'EntryDevices'(POE}, -Point-of-Use Devices (POU), and Bottled Water

POE may be used to achievecompliance with MCLs;'however, POE isnot BAT.

POU and bottled -water cannot-beusedtoachieveconpliance with theMCLs;.-however,-either may,.at Statediscretion, be-acondition.ofgranting-avariance or.exemption.

Variances. and Exemptions

Prior'toissuing~a,-variance.orexemption, the:State has the authoritytorequire, the-publicwater. syrtemtoimplement additional interim controlmeasures.if.an-unreasonableirisk~tohealth exists;. amongother mitigation

- techniques, States may.require-installdtiono6f:point-of-use -devices ordistribution:of:bottled:waterto-eachcustomer as-measuresto reduce thehealth-riskbefore grantinga varianceorexemption.

Monitoring for. UnregulatedContaminants

One sam ple-per: sourceis-requiredevery-five:years.

SyStems samlole according to theprocedures and schedules establishedfor VOC compliance monitoring.

,Monitoringlorthe-50,unregtilatedcontaminants'is as specifiedlbelow:

List 1:.monitoring xequiredfor allsystems (34 contaminants).

List 2: monitoring required forvulnerable systems(2, contaminanits).

List 3: monitoring required at Statediscretion'(15 contaminants).

Repeat monitoring frequency: Everyfive years.

EPA will specify a new list beforerepeat monitoring is required: (withinfive years).

II. Background

A.-Statutory Authority

.Section 1412 of the. Safe-DrinkingWaterAct, as amended in 1986("SDWA" or'"the Act"), requires EPA topublish Maximum Contaminant LevelGoals (MCLG9) and promulgateNational Primary Drinking WaterRegulations [NPDWRs) forcontaminanits'in drinking water whichmay cause any adverse effect on thehealth df persons and which areknown,or anticipatedto.occur~in public watersystems. Under'Section 1401, theNPDWRs are to include MaximumContaminantLevels [MCLs) and"criteria and procedures to assure asupply of drinking water whichdependably complies" with such MCLs.Under Section 1412(b)(7)(A), if'it is noteconomically or technically feagible toascertain the lev6l-of a contaminant indrinking water, EPA may reqtiire'the useof a treatment technique'instead of anMCL.

:25691

25692 Federal Register / Vol. 52, No. 130. / Wednesday, July 8, 1987 / Rules and Regulations

1. MCLs, MCLGs, and BAT

EPA is to establish MCLGs at thelevel at which no known or anticipatedadverse effects on the'health of personsoccur and which allow an adequatemargin of safety. MCLGs arenonenforceable health goals. EPApublished MCLGs, previously calledRecommended Maximum ContaminantLevels (RMCLs), for trichloroethylene,carbon tetrachloride, 1,1,1-trichloroethane, vinyl chloride, 1,2-dichloroethane, benzene, 1,1-dichloroethylene, and para-dichlorobenzene on November 13, 1985.The Agency reproposed the MCLG for p-DCB on April 17, 1987 (52 FR 12876),based on new health assessment data.

MCLs are enforceable standardswhich the Act directs EPA to set asclose to the MCLGs as feasible."Feasible" means feasible with the useof the best technology, treatmenttechniques, or other means which theAdministrator finds available (takingcost into consideration) afterexamination for efficacy under fieldconditions and not solely underlaboratory conditions. Also, the SDWArequires the Agency to identify the bestavailable techn6logy (BAT] which is'feasible for meeting the MCL for each.contaminant. NPDWRs are to beamended whenever changes intechnology or other means permitgreater protection of the health ofpersons, and the regulations are to bereviewed no.less frequently than every,three years.

2. Variances and Exemptions.Section 1415 authorizes the State (the

term "State" is used in this Preamble tomean the State. agency with primaryenforcement responsibility for the publicwater supply system program, or"primacy," or EPA if the State does nothave primacy) to issue variances fromNPDWRs. The State may issue avariance if it determines that a systemcannot comply with an MCL despiteapplication of the'best availabletechnology (BAT), Under Section 141.5,EPA must propose and promulgate itsfinding of the best technology,. treatmenttechniques, or other means available foreach contaminant (BAT), for purposes ofSection'1415 variances, at the same timethat it proposes and promulgates amaximum contaminant level for eachsuch contaminant. EPA's finding of besttechnology, treatment techniques, orother means available for purposes ofissuing. variances may vary amongsystems, depending upon the number ofpersons served by the system or forother physical conditions related toengineering feasibility and .csts of

complying with MCLs, as consideredappropriate by EPA. The State may notissue a variance where an unreasonablerisk to health exists. When a Stategrants a variance, it must at the sametime prescribe a schedule for (1)compliance with the NPDWR and (2)implementation of such additional-control measures as the State mayrequire.

. Under section 1416(a), the State mayexempt a public water system from anyMCL or treatment techniquerequirement if it finds that (1) due tocompelling factors (which may includeeconomic factors), the system is unableto comply, (2) the system was inoperation on the effective date of theMCL or treatment technique, or, for anewer system, that no reasonablealternative source of drinking water isavailable to that system, and (3) theexemption will not result in anunreasonable risk to health, Undersection 1416(b), at the same time itgrants an exemption, the State is toprescribe a compliance schedule and aschedule for implementation of anyrequired interim control measures. Forexemptions from a NPDWR promulgatedafter enactment of the SDWAamendments, such as the NPDWRs forthe VOCs promulgated in this notice, thecompliance date must be no later than12 months, after the date of issuance ofthe exemption. However, the State mayextend the final compliance date for aperiod not to exceed three years afterthe date of issuance of the exemption ifthe public water system establishes thatit is taking all reasonable steps to meetthe standard once: (1) the system cannotmeet the standard without capitalimprovements which cannot becompleted Within the period of suchexemptions; (2) in the case of a systemwhich ,needs financial assistance for thenecessary improvements, the system hasentered into an agreement to obtainsuch financial assistance; or (3) the •system has entered into an enforceableagreement to become part of a regional.public water system. For systems.thatserve 500 or fewer service connectionsand which need financial assistance tocome into compliance, the State mayrenew the exemption for additional two-year periods if the system is taking allpracticable steps to meet therequirements in the previous sentence.

3. Primacy.

Today's regulation is one of manywhich EPA will promulgate during thenext few years, as required by the 1986Amendments. To retain primaryenforcement responsibility ("primacy")for the public water system supervisionprogram, States must revise their

programs to include regulations that areno less stringent than the FederalNPDWRs, as required by Section 1413 ofthe Act: EPA plans to amend the PublicWater System Supervision (PWSS)Program Implementation regulations, 40CFR Part 142, to set out the requirementsfor these program revisions. Theamendments will be based on therecommendations of an EPA workgroupwhich is currently reviewing the issues,associated with such requirements.However, since these VOC regulations,promulgated under the authority ofSection 1412, go into effect 18 monthsfrom the date of this notice, States mustbegin to modify their programsimmediately without waiting for theamendments to 40 CFR Part 142.

The 18-month interval derives fromSection 1412(b)(10) of the SDWA whichrequires that all NPDWRs be in effect nolater than 18 months after thepromulgation date. EPA takes theposition, therefore, that the FederalNPDWRs directly apply to public watersystems regardless of whether a Statewith primacy has adopted therequirements. As such, EPA has somediscretion in establishing when Statesadopt the NPDWRs promulgated intoday's notice since the Federalregulations will apply to all systems,even in States with primacy that havenot adopted equivalent requirements.

EPA wishes, however, to avoid Stateshaving "split" or "partial" primacy, i.e.,authority to implement and enforce onlypart of the, PWSS program, for morethan a short time. As such, EPA expectsprimacy States, to the maximum extentpossible, to adopt State requirements asstringent as those contained in thisFederal regulation within 18 months.Splitting oversight responsibilities,however briefly, will confuse publicwater system owners and operators asthey try to determine which State andFederal regulations apply to them. Inaddition, EPA implementation andenforcement of regulations that Stateswith primacy have not yet adopted willbe limited since the EPA RegionalOffices are not currently set up, orfunded, to implement a day-to-dayoperational program. EPA believes thatStates should operate the total PWSSprogram, including the changescontained in any new regulations, fromthe effective date onward.

As the monitoring requirements of thisregulation go into effect sooner thaneighteen months after publication i.e.,January 1, 1988, States with primacyshould inform systems under their.

* jurisdiction of their responsibilitiesunder Federal law and ensure that theyare monitoring even though the State

rFederal Register /'Vol. 52, No. 130 j/ Wednesday, July 8, 11987 / Rules iand Regulations

may not yet have:its requirements inplace. Further,. States. should colleatandmanage the analyticahresults during.thisinterim period as:though they;hadincorporated the:program revisions.States should forward information onviolations of theFederal requirementstothe applicable EPA Regional Office.

As mentioned in the first paragraph ofthis section,;EPAplans to specify,.-aspart of the.revisions to 40CFRLPart 142,the materials States are'to submit toEPA so the Agency can determinewhether a State-has adoptedrequirements that are no less stringentthan'the FederalNPDWRs. Stateprogram revisions that occurlbeforechanges to 40,CFRPart 142 arepromulgated must,. however, bereviewed by.EPA as well. States mustdemonstrate to EPAthat their programrevisions allow-them to continue totneetthe requirements ofsection 1413(a).ofthe SDWA and 40 CFR 142.10 of theImplementation-regulations. For.example, EPA must review the State'simplementing statutory andregulatorychanges. It may, beinecessary imsomeinstances for States toprovide a StateAttorney General's opinion specificallyexplaining how the State's statutes andregulations give it the authority toimplement and enforce;the newrequirements. Specific to theprogramrevisions contained in today's Federalnotice, States must also-provide theirmethodology for determiningthevulnerability of a public water system asthis is an integral part of determining thepublic water system monitoringrequirements. States should-provide thisinformation to EPA through theapplicable EPA Regional Office. Toensure consistency with Federalrequirements, EPA encourages States toinvolve the Regional- Officesduring thedevelopmental stages of anyinewstatutes or regulations rather thanwaiting until after.final adoption.

It is important that public watersystems be aware of theirresponsibilities under the Federalregulations. Systems in States-witholtprimacy are subject to the Federalrequirements on-the effective date of.theNPDWRs, i.e., 18 months frompublicationin the FederalRegister(except for monitoring requirementswhich are effective Januaryl, 1-988).Public water systems, located, in Stateswhich do not haveprimacy shallforward all analytical results andlotherinformation required by~thisW'regulationto EPA directly.

Systems located in States whichhaveprimacy,.but. havei not. adopted'therequirements, contained in-thisregulation,.must comply -with.Federal

requiremerits.:Failure.by, a State withprimacy to establish its-wnrequirements doesmotexemptra systemfrom ' the .Federal requirements. andsystemsvwhich violate aFederalrequirementcontained in;this regulationwillbe sdbject:to Federail eiforcement.Public walter sygtems located in'Stateswith-primacy should,'however, reportanalytical results'and all otherinformation required by this regulationto the Stateevenif the State'has not yetadopted the requirements oftheregulation.-Itwillbe theresponsibility ofthe State,'in such cases,'to'forwardinformationtotEPA.

4. Monitoiing, Quality ControluandRecords

Under section 1401(i)(D).of the Act,NPDWRs are to contain "criteria.andprocedures to assure.a..supply of

drinking water which, dependablycomplies with such- maximumcontaminant levels; including' quality.control and testing procedures-to insure'compliance with such levels ... "ln.addition, Section 1445.states that, "everyperson who isa-supplier-of water .shall establish and maintain suchrecords, make. suchreports,, conductsuch monitoring and provide, suchinformation as the Admiiistrator mayreasonably-require by regulation'toassist him in establishing.regulations,...in evaluating thehedlth risks-dfunregulated.contaminants or in advisingthe public, of such:risks."'Section 1445also-requires EPAIto promulgateregulations.requiring every public watersystem-to Conduct a moniitoring-programfor unregulated contaminants.

5. Non-transient Nontcommunity WaterSystems

Public water systems are defined inthe Act at section 1401()(D)(4) as thosesystems which provide piped water forhuman consumption and'have at leastl5connections or regularly-serve-at least25 people. 'Thecategory "public watersystem" is composed, df community andnon-community water systems. Thecommunity water system is one whichserves atleast 15 connectionsusedbyyear-round residents or regularly.servesat.least 25-year-round. residents (40 CFR141.2). Non-community systems,. bydefinition, are all-other water systems.Non-community systems includetransient systems (e.g., campgrounds,gas stations) and non-transient systems(e.g.,sdhools, woikplaces,'hospitalswhich 'have their, own watersupplyi andserve the sameppulationover sixmonths of-a year), asenolhined in moredtail~later.

6. PubllcNotification

Section'1414(d) ofthe Act-requirestheowner or-operator.df a~publicwatersystem whidh'fiils to-comply with anapplicable-maximum contaminantilevdlor treatmeilt'tedhnique:requirement,testing procedure,,or'setion'145(a)monitoring reqdirement to give notice-tothe-persons served bythe-water system.Owners and8operators of public watersystemsafor Whidh variancesorexemptions'are'ineffect,'orwhich fail tocomply With the requirement of anyscheddle imposed pursuantlto avariance, orexemption, must also givendtice.'Sectionl'445(a)(5) also-Tequirespublic water systemsto-ndtifylthepersons servedby the,water-system andthe Administrator, f EPA of theavailability dfrthe results of monitoringfor unregulated. contaminants.

B. Regulatory'Background

On June 12,1984{49FR 24330), EPAproposed MCLGs for'the eight VOCscovered in'today's notice: Benzene,caibontetrahlorie, 1,2-dichloroethane,trichloroethylene, 1,1-dichloroethylene,1;,1-trichloroethane, para-idichlorobenzene,;and vinyl chloride. On'November 13,'1985, EPA-publishedthe'final MCLGs andproposed MCLsforIthese eight VOCs;(50 FR 46880and s0FR 46902). Detailed discussions.dfthehistory,of the regulation.of VOCe indrinking-water-together withinformation on occurrence in drinkingwater and any, adverseeffedts'of humanexposure wererpresented in thesenotices.This background is summarized;below. EPA-prqposed to amend-theMCLG for para~dichlorobenzene (p--DCB),and reproposed the:MCL forp-DCB on !April17, 1987,(52:FR -12876).

1. MCLGsMCLs, -and Monitoring

fIn the November',13, 1985,-notice forsubstances considered'to beknown:orprdbable human.carcinogensEPA setthe MCLGsat.zero.,For sdbstances-it.didnot consider-Inown or probable humancarcinogens, ,EPA:set the MCLGs basedupon chronic-toxicity -data. Table 1summarizesthe final-MCLGs for-theseVOCs. TherChemicaluManufacturersAssociation,-the:Halogenated, SolventsIndustryAlliance, and-the NaturalResources Defense Council -each filedpetitions forreviewof-one.ormore ofthese MCLGs.'rrhesepetitions arependingbeforethe- U.S.-Court of.Appeals:for theDistrict-ofCdlumbiaCircuit.

The.establishmentoftan,MCLG.atzero doesnotimply,that-actual harmwould.necessaBily occur:toihumans, at. alevel somewhat-above -zero, rbut,ratherthat:zero is-an aipirationalgoal, -which

IT.A93


includes a margin of safety, within thecontext of the Safe Drinking Water Act;MCLs, even though set at levels aboveaspirational MCLGs, based onfeasibility considerations, are alsoconsidered safe levels that areprotective of public health.

EPA proposed the MCLs for the eightVOCs based upon an evaluation of (1)the availability and performance oftreatment technologies [Best TechnologyGenerally Available (BTGA), underSections 1412 and 1415, was identifiedas PTA or GAC], (2) the availability,performance, and cost of analyticalmethods, and (3) an assessment of thecosts of application of varioustechnologies to remove VOCs fromdrinking water to variousconcentrations. Table ,1 summarizes thefinal MCLGs and the proposed and finalMCLs that EPA is promulgating in thisrule.

TABLE 1.-FINAL MCLGs AND PROPOSED ANDFINAL MCLs FOR'THE VOCS

Final Proposed FinalCompound MCLG MCL (mg/ MCL

(mg/I) I) (tg/I)

Benzene .................................... Zero 0.005 0.005Vinyl chloride ............................ Zero .001 .002Carbon tetrachloride ................ Zero .005 .0051,2-Oichloroethane.................. Zero .005 .005Trichloroethylene ........... Zero .005 ;.005p-Dichlorobenzene °.

................ 0.075 .005 .0751,1 -Dichloroethylene ................ .007 .007 .0071,1,1-Tichloroothane .............. .20 .20 .20

*Reproposed on April 17, 1987, at zero and 0.005.

As described above, the Agencyproposed to amend the MCLG andreproposed the MCL at 52 FR 12876(April 17, 1987) for para-dichlorobenzene(which is the common name for 1,4-dichlorobenzene). These proposals werebased upon results of a newNationalToxicology (NTP) study. Based on apreliminary assessment of the totalweight of evidence of the toxicologicalstudies, EPA proposed to reclassify p-dcb as a Group B2 substance under theAgency's Guidelines for CarcinogenRisk Assessment at 51 FR 33992(September 24, 1986). This notice on p-dcb also indicated that EPA wasconsidering classification of p-dcb inGroup C instead of B2. The Agencyasked for public comment on theappropriate classification based on theweight of evidence.

In the November 1985 notice, EPAproposed to require'non-transient non-community water systems to meet thesame requirements as community watersystems by broadening the definition of"community water systems." Thiscategory of public water systemsincludes such systems as schools and-factories where the saime consumersmay be exposed not only for part of the

day but throughout much of the year,and often for many years. " -..

At the same time that EPA proposedthe MCLs, it also proposed minimumcompliance monitoring requirementsconsisting of one initial round ofmonitoring to determine the extent ofcontamination and certain follow-upmonitoring requirements if the initialround of. monitoring. indicated VOCcontamination. The November 1985notice also proposed monitoringrequirements for 51 additionalunregulated contaminants (all VOCs)under Section 1445. These requirementswere very similar to the compliancemonitoring requirements proposed forthe eight MCLs. The major differencewas that for the unregulatedcontaminants only one round ofmonitoring was proposed (thecompliance monitoring requirementscalled for repeat sampling ranging infrequency from quarterly to every 5years, depending on the prior monitoringresults and a determination of asystem's vulnerability tocontamination).2. Reporting and Public Notice

EPA also proposed reporting andpublic notice requirements for VOCs inthe November 1985 notice. The proposedrequirements were identical to thosecurrently in place under the NationalInterim Primary Drinking WaterRegulations (now simply "NationalPrimary Drinking Water Regulations").No change in the public noticerequirements was proposed at that time.

For unregulated contaminants, theproposed regulations would haverequired the PWS to notify itsconsumers of the availability of theanalytical results of the unregulatedcontaminant monitoring and to submit arepresentative copy of each publicnotice to the State. In addition, theresults of the monitoring were to besubmitted to the State.

In response to the SDWAamendments of 1986, which revised thepublic notification requirements inSection 1414(c), EPA recently proposedchanges to public notificationrequirements in 52 FR 10972 (April 6,1987). That proposal includes specificexplanations of the potential healthrisks of exposure to the eight VOCs intoday's final rule. Those explanationswere proposed to be required in eachpublic notice for failure to comply withany MCL

C. Public Comments on the'ProposalEPA requested comments on all

aspects of the November 13, 1985,proposal and.the April17, 1987,reproposal. A detailed summary of the

comments received and the Agency'sresponses are presented in thedocument "Summary of Comments andEPA responses on the Proposed MCLsfor the VOCs, Reproposed MCLG/MCLfor para-Dichlorobenzene, andRequirements for MonitoringUnregulated Contaminants," availablein the public docket. General Summariesof comments, with responses, pertainingto specific MCL issues are presented inthe relevant sections of this notice.

EPA received over 250 writtencomments on the November 1985proposed rule, including 39 fromindividuals, 20 from companies, 45 fromwater utilities or water utilityassociations, 10 from trade associations,101 from Federal agencies,-States, andlocal governments, and 44 from othergroups (primarily mobile home parkoperators). EPA held a public hearing inWashington, D.C., on January 13, 1986,and received an additional 10 commentsat that time. Additional comments werereceived at the May 4, 1987, public.hearing as well as in writing during thepublic comment period on the April 1987reproposed MCLG and MCL for para-dichlorobenzene.

III. Explanation of Today's Actions

A. Non-Transient Non-CommunityWater Systems

In the November 1985 notice, EPAproposed to redefine the term"community water system" to includecertain non-community water systemsas follows:

Community Water System means a publicwater system which serves at least 15 serviceconnections used by year-round residents orregularly serves at least 25 of the samepersons over 6 months per year. " "

The purpose of the change was to.protect nonresidential populations ofmore than 25 people who, because ofregular long-term exposure, might incurlong-term risks of adverse health effectssimilar to those incurred by residentialpopulations. The change was designedto include systems serving more than 25persons in such places as workplaces,offices, and schools, that have their ownwater supplies.

EPA requested comment on thisproposal. About half the commenterswho addressed this issue supported thechange, citing the potential health risksfrom exposure in these non-transientsituations. The other commenters statedthat the resource burden to the Statesand the regulated community would beexcessive and felt that the potentialbenefits would not outweigh the costs.I EPA believes applying NPDWRs to

such systems is protective of public

Federal Register / Vol. 52, No. 130 / Wednesday, July 8, 1987 / Rules and Regulations

health and should be implemented. EPAbelieves the risks to consumerscommonly associated with long-termexposures to contaminated drinkingwater in many cases could also apply toNTNCWS drinking water consumers,such as factory employees and schoolchildren exposed to the same drinkingwater source over a number of years.The chronic health risks to consumers innon-transient water systems would besimilar to residential populations servedby community water systems, since onecan estimate that one-third to one-halfor more of the normal daily waterconsumption would occur at the schoolor workplace, and the rest at home.Therefore, EPA believes it is appropriateto apply NPDWRs to both communityand non-transient non-community watersystems. However, water from' systemsserving populations for only a brief time(e.g., campgrounds, parks, gas stations)does not pose long-term health risk suchas those associated with the VOCs.Therefore, EPA believes that it is notnecessary to regulate water systems thatonly serve transient population foragents of chronic exposure but thesewater systems should be regulated foracute risks (e.g., nitrates).

Instead of amending the definition ofcommunity water systems, as proposedin the November 1985 notice, EPA ispromulgating a definition of "non-transient, non-community watersystems" and applying the NPDWRs forthe eight VOCs to those systems (aswell as community water systems, ascurrently defined in EPA's regulations).This term includes the universe of non-transient systems that EPA included inthe revised definition of communitywater systems it proposed. Thisapproach is preferable to the proposedapproach because if EPA amended thedefinition of "community water system"to include non-transient non-communitysystems, then all of the existingNPDWRs would apply to those systemsby definition. This is not EPA's intent.However, EPA does intend to applyfuture NPDWRs to non-transient non-community water systems as itevaluates and revises the existingregulations, as required by the 1986amendments to the SDWA. Inconclusion, EPA is amending 40 CFR141.2 to add a new definition as follows:

A "non-transient non-community watersystem" means a public water system that isnot a community water system and thatregularly serves at least 25 of the samepersons over six months per year.

B. MCLG for Para-dichlorobenzeneIn this notice, EPA has placed p-dcb in

the Group C category (limited evidenceof carcinogenicity in animals). (See 51

FR 33992, September 24, 1986, for a fulldiscussion on EPA's Guidelines forCarcinogenic Risk Assessment.) OnNovember 13, 1985, the Agencypromulgated an RMCL for p-dcb as aGroup D substance, based on chronictoxicity data from the studies availableat that time.

After that notice was published, theAgency received the results of a long-term study on p-dcb conducted by theNational Toxicology Program (NTP)(Ref. 6). The NTP study was a chronicbioassay which used F344 rats andB6C3F1 mice. Tumors were found inboth species of animals at incidenceswhich were statistically significant.Therefore on April 17, 1987 EPAreproposed the MCLG for p-dcb. TheEPA proposed the MCLG considering aclassification of B2 for p-dcb butacknowledged the controversysurrounding this classification andpresented an alternative Group Cclassification. Public comments weresolicited on whether p-dcb should beclassified as a B2 or C substance. Theconclusions of these comments receivedon this proposal differed even thoughthey were using the same criteria in theguidelines; eight commenters wouldplace p-dcb in group C, two in Group B2.

The Agency recognizes that as withmost chemicals, the evaluation of thecarcinogenicity potential of p-dcb inhumans is a difficult and somewhatcontroversial activity, in light ofdivergent interpretations made by thescientific community. Because it isnecessary for the Agency to make ajudgment based on a reasonableweighing of the evidence from the dataat hand, at this time p-dcb is beingclassified in category C (possible humancarcinogen).

At issue in the controversy of theclassification is whether there exists"sufficient" evidence of carcinogenicity(i.e., B2 classification) or whether thereis only "limited" evidence ofcarcinogenicity (i.e. Group C).

A Group B2 substance is defined bythe following factors:

An increased incidence of malignanttumors or combined benign andmalignant tumors in:

(a) Multiple species or strains,(b) In multiple experiments (e.g., with

different dose levels and routes ofexposure) or

(c) To an unusual degree in a single.experiment with regards to a highincidence; unusual site or.type of tumor.or early age at onset.

A Group C is defined by the followingfactors:

Having limited animal evidence ofcarcinogenicity in the absence of humandata in which:

(a) The studies involve a single animalspecies, strain or experiment and do notmeet criteria for sufficient evidence.

(b) The experiments are restricted byinadequate dosage levels, inadequateduration of exposure,'or inadequatereporting, or

(c) The studies show an increase inthe incidence of benign tumors only.

As pointed out in these Guidelines,this classification is not meant to beapplied rigidly or mechanically, but abalanced judgment of the totality of theavailable evidence needs to beconsidered. This Weight of the evidenceapproach can increase the number ofreasonable interpretations to the samedata base.

Decision Process

Evaluating the increased male ratkidney tumors and liver tumors in maleand female mice of the NTP 1986bidassay, p-dcb might be tentativelyclassified in Group B2: probable humancarcinogen. However, when reviewingthe total weight of evidence at thisjuncture, p-dcb could also be classifiedin Group C: possible human carcinogen.Factors relevant to determining weightof evidence include: 1) evidence ofcarcinogenicity, 2) structure/activityrelationships, 3) genotoxicity testfindings, and 4) results of appropriatepharmacokinetic and toxicologicalobservations.

Because the carcinogenicity bioassays(discussed under Evidence ofCarcinogenicity) do not provideunequivocal evidence of carcinogenicpotential for humans, it is necessary toconsider all factors in determining theweight of evidence for p-dcbcarcinogenicity.

(1) Evidence for Carcinogenicity.Evidence for the carcinogenicity ofp-dcb is primarily limited to the NTPstudy of F344 rats and B6C3F1 mice. Inthis study, rats and mice were exposedto two doses of p-dcb in corn oiladministered via gavage. The NTPconcluded that there was clear evidenceof carcinogenicity both for male rats asshown by an increased incidence ofrenal tubular cell adenocarcinomas andfor mice of both sexes as shown byincreased incidences of hepatocellularcarcinomas and hepatocellularadenomas. No evidence ofcarcinogenicity was seen in female rats.

The issue in interpreting theguidelines is to determine the relevanceof both the male rat kidney and mouseliver tumors to human carcinogenesis.

25695


Induction of male rat kidney tumorsby several nongenotoxoc organicchemicals has been linked to thepresence of hyaline droplets composedof alpha-2u-globulin, a protein whichhhs not been detected in female rats,mice or humans. There is evidence forthe formation of hyaline droplets inmale rats given p-dcb orally. It has beenasserted by several investigators andcommenters, and supported bysubstantial data, that alpha-2u-globulinis essential for hyaline droplets in themale rat kidney. Presence of hyalinedroplets seen only in the male ratkidney, which was the target organ inthe NTP bioassay, and lack of hyalinedroplets in the female rat kidney, whichwas not a target organ, supports thehypothesis that hyaline dropletsformation may have limited significancefor human exposure to p-dcb. Themechanism of carcinogenesis is notabsolutely certain but the involvementof alpha-2u-globulin is a probable andsound scientific explanation that hasbeen developed from a large body ofmechanistic and pharmacokineticstudies on this chemical.

The significant increase in mortalityindicated that the MTD was exceededfor the high dose male rats.

Diminished toxicological significancemight be ascribed to mouse liver tumors,which are induced by a number ofchlorinated hydrocarbons. As withtumors of the male rat kidney, theorieshave been proposed which argue thatthe mouse liver response is not relevantto humans. Explanations are stilltentative and the possible relevance tohuman carcinogenicity is a current topicof debate.

Other bioassays have been performedwhich although having someshortcomings confirm the negativeresults in the low dose NTP bioassayresults. Alderly Part Wistar rats wereexposed to multiple doses of p-dcb viainhalation for 76 weeks, followed by anadditional 36 weeks of observation(Riley et al., 1980, described in Ref. 8).No increases in tumor incidence or typewere observed. Comparisons of thisstudy with the NTP bioassay are madedifficult because of the differences in theroute and duration of exposure.However, if 0.1 liter/minute wasassumed as the breathing rate for 500gram rats exposed to p-dcb for fivehours/day, five days/week for seventy-six weeks, the estimated daily oral dosewould be 178 mg/kg. This estimateddose is slightly higher than the low doseof 150 mg/kg in male rats, which did notproduce a significant increase in kidneytumors, as reported from the NTP study.While the shorter duration of exposure

may be responsible for diminishedtumorigenic response, the variety oftoxic effects (increase in liver, kidney,heart and lung weights, increase inurinary protein and coproporphyrinoutput) in the high dose group (500 ppm)indicate that the MTD was approached.

Subchronic studies havedemonstrated evidence of liver andkidney toxicity and a variety of othertoxic effects from p-dcb exposure toanimals either via gavage or inhalation(Hollingsworth, 1956, 1958; described inRef. 8). No evidence of carcinogenicitywas found, but the short duration ofthese studies (6-month duration)precludes detecting carcinogenic effectsunless the latency would be unusuallyshort and the compound were a potentcarcinogen.

No evidence of carcinogenicity inhumans has been reported, which is notunusual. Therefore, inadequate data areavailable to assess the weight ofevidence for carcinogenicity fromepidemiological/case studies in humans.

Thus, considering the totality ofevidence, the available bioassay dataare equivocal as a basis forextrapolating to humans and theepidemiological data are inadequate. Inthe judgment of the Agency, a Group Cclassification for p-dcb would be moreappropriate than a B2 classificationbased upon the information currentlyavailable.

(2) Structure-Activity. Compoundswith similar chemical structures havebeen tested in long-term carcinogenicitybioassays, but no clear evidence ofcarcinogenicity has been reported. Suchstructure-activity information can beuseful when evaluating closely relatedchemicals.

Two compounds with similarstructures to p-dcb(orthodichlorobenzene (o-dcb) andmonochlorobenzene (mcb)) have beentested in NTP bioassays. As with p-dcb,the compounds were administered incorn oil via gavage to F344 rats andB6C3F, mice. Under test conditions, o-dcb was not carcinogenic at doses of 60and 120 mg/kg administered for 103weeks. For mcb, an increase ofneoplastic nodules of questionablestatistical significance was found forhigh-dose male rats (120 mg/kg). Both o-dcb and mcb have been classified asGroup D: inadequate evidence forcarcinogenicity.

Metabolites of p-DCB (2,5-dichlorophenol and its hydroquinone)have not been tested for carcinogenicity.2,4-Dichlorophenol was administered indrinking water in a two-year bioassay inrats (Exon and Koller, 1985; described in

Ref. 8) and found to produce no increasein tumors, but was cocarcinogenic whenadministered with ethylnitroso urea*ENU). 2,4-Dichlorophenol has not beenformally classified, but could becategorized as Group D: inadequateevidence for carcinogenicity.

Structure activity relationships alonecannot be the sole Lasis for discountingpositive findings, but they do detractfrom the overall weight of evidence ofcarcinogenicity in this case.

(3) Genotoxicity Tests. p-Dcb wasdetermined not to be genotoxic from avariety of short-term genotoxicitybioassays. Therefore, it is less likelythat it could be carcinogenic by agenotoxic mechanism. Genotoxicity isoften associated mechanistically withcarcinogenicity. Some non-genotoxicsubstances are carcinogenic byunknown mechanisms.

p-Dcb is not mutagenic when tested inSalmonella typhimurium or in the E. coliWP2 system. Increased frequency ofback mutation was observed on themethionine requiring forms in the fungusAspergillus nidulans, however thisfinding is not considered significant.

p-Dcb was not found to induceforward mutations in mouse lymphomacells, sister chromatid exchange inChinese hamster ovary cells orunscheduled DNA synthesis in humanlymphocytes. Negative results were alsoobtained in cytogenicity studies with ratbone marrow cells and a dominantlethal study in CD-1 mice followingexposure to p-dcb.

(4) Pharmacokinetic andToxicological Observations.Commenters also raised questions onthe relevance of the results of the NTPbioassay to exposure of humans to p-DCB via drink water. Issues include thetoxicological significance of the mode ofadministration (gavage vs. drinkingwater) and the vehicle used (corn oil vs.drinking water).

With respect to both mode ofadministration and vehicle, no data areavailable specifically on p-dcb, butbioassays on other chlorinatedhydrocarbons have shown that thepharmacokinetics of absorption/distribution differ between compoundsadministered in corn oil via gavagecompared to drinking wateradministration. The issue thatthe cornoil vehicle itself may affect hepaticmetabolic capabilities and influence thesusceptibility of the mouse to hepatictumors has been a subject ofcontroversy. No. data are availablespecifically on p-dcb.

Federal Register / Vol. 52, No. 130 I Wednesday, July 8, 1987 I Rules and Regulations 25697Conclusion

Therefore, in considering the totalweight of evidence: One positive studyin two animal species, a partiallycorroberating study in one species, nohuman evidence, no replication of theresults in animals, negative evidence ofcarcinogenicity in structurally similarcompounds, negative mutagenicitystudies, uncertainties with mode ofadministration and controversysurrounding the significance of the ratkidney and mouse liver tumor results, atthis time the EPA establishing the

MCLG and MCL for p-DCB consideringp-dcb as a Group C carcinogen.

The classification of p-dcb as a GroupB2 or Group C substance is acontroversial one. EPA will reassess thisclassification as new informationbecomes available. This reclassificationresults in a reduction of the prior MCLG(RMCL) by a factor of 10 from 0.75 to0.075 mg/l.

An MCLG of 0.075 mg/l (75 Ag/l) hasbeen calculated based on chronictoxicity data. The MCLG was calculatedas follows:

reference dose (0.1 mg/kg/X body weight day)(70g)DWEL - - = 3.75 mg/I

daily water 21/dayconsumption

MCLG =

drinking water equivalent levelx relative source contribution

additional uncertainty factor

3.75 X

MCLG = 0.2 = 0.075 mg/l (75 pg/l)10

Where the reference dose is calculated as:

no observable effect levelRfD

uncertainty factor

150 mg/kg/day(5) 0.1 mg/kg/

1000 (7) day

The classification of Group C is alsoconsistent with the recommendations ofthe National Drinking Water AdvisoryCouncil, the transcript of a meeting heldby the Halogenated SolventsSubcommittee of the EPA ScienceAdvisory Board on p-dcb. Eight out ofthe ten commenters who responded tothe request for comment of the para-dichlorabenze classification supportedthe Class C decision.

Had p-dcb been assigned to Group B2,the 95% upper-limit carcinogenicpotency factor for humans, q,*, wouldbe the basis for the quantitation. A"what if' calculation for p-dcb, using thedraft qi* value is 2X10- (mg/kg/day)"' .by the multistage model and male mouseliver tumor data indicated an upper-limitindividual lifetime cancer risk of 4 X 10-5

for a 70 kg human drinking 2 L/water aday for a lifetime (assumed to be 70years) exposure to drinking watercontaining 75 gg/L.

C MCLs for VOCs

In this rule, EPA is promulgatingMCLs for the eight VOCs as follows:

Compound Final MCL(mold)

Benzene .................................................................. 0. 0 5Vinyl ct oride .......................................................... 0.002Carbon tetracNoride ............................................. 0.0051,2-Dchloroethane ........................ 0.005Tdichoroethytene .................................... .005para-Dichlorobenzene..... ................................. 0.0751 ,1-Dichloroethylone .............................................. 0.007.l,l-Tric toroehan ........................................... 0.2

As noted earlier, section 1412(b)(4) ofthe Act requires EPA to set MCLs asclose to the MCLGs as is feasible.

Section 1412(b)(5) of the Act defines"feasible" to mean "feasible with theuse of the best technology, treatmenttechniques and other means which theAdministrator finds, after examinationfor efficacy under field conditions andnot solely under laboratory conditions,are available (taking cost intoconsideration)," i.e., "BAT."

This provision represents a changefrom the provision prior to 1986, whichrequired EPA to judge feasibility on thebasis of "best technologies generallyavailable" ("BTGA"). The 1986amendments changed BTGA to BAT andadded section 1412(b)(5), whichspecifies that the technology selected asBAT must be tested for efficacy underfield conditions, not just underlaboratory conditions. The legislativehistory explains that Congress removedthe term "generally" to assure thatMCLs "reflect the full extent of currenttechnology capability." [S. Rep. No. 56,99th Cong., 1st Sess., at 6 (1985)]. Readtogether with the legislative history,EPA has concluded that the statutoryterm "best available technology" is abroader standard than "best technologygenerally available" and that thisstandard allows EPA to select atechnology that is not necessarily inwidespread use, as long as it has beenfield tested beyond the laboratory. Inaddition, EPA believes this change inthe statutory requirement means that thetechnology selected need notnecessarily have been field tested foreach specific contaminant. Rather, EPAmay project operating conditions for aspecific contaminant using a field testedtechnology from laboratory or pilotsystems data.

Based on the statutory directive forsetting MCLs, EPA derives the MCLsfrom an assessment of a range ofpertinent factors, including theavailability and performance of BAT,the costs of these technologies fordifferent size water systems, and thenumber of water systems that wouldhave to install technologies. EPA alsoevaluates the availability of analyticalmethods and the reliability of analyticalresults as well as the resulting health

Federal Register / Vol. 52, No. 130 /,Wednesday, July 8, 1987 / Rules and Re'gulations' ' , '25697


risks of various contaminantconcentration reduction levelsattainable by BAT. For drinking watercontaminants, the target reference riskrange for carcinogens is 10- 4 to 10-6 andmost regulatory actions in a variety ofEPA programs have generally fallen inthis range using conservative modelswhich are not likely to underestimatethe risk. Of course, MCLs could be setoutside the range depending upon thefeasibility of achieving.a specific level.1. Treatment Technologies

As explained in the November 1985proposal, EPA examined a number oftreatment processes for their potential toreduce the level of VOCs in drinkingwater. These technologies are discussedin the document "Technologies andCosts For The Removal of VolatileOrganic Chemicals From Potable WaterSupplies." (Reg. 2). (A draft of thisdocument was available at the time ofthe proposal. The final document isavailable from the National TechnicalInformation Service at the address listedin Section VI of this notice.)

In reviewing the different technologiesavailable, EPA looked at the followingfactors: Removal efficiency, degree ofcompatibility with the other watertreatment processes, service life, and theability to achieve compliance for all thewater in a public water system.

Based on these criteria, in theNovember 1985 notice, EPA proposedgranular activated carbon (GAC) andpacked tower aeration (PTA).as "best"technologies for removing VOCs fromdrinking water. As described in thatnotice (50 FR 46914), these technologieshave the following characteristics: goodremoval efficiencies (90 to 99 percent);compatibility with other types of watertreatment processes: reasonable servicelife; and ability to achieve compliancefor all the water in a public watersystem. In addition, these twotechnologies are commercially availableand have been used successfully toremove VOCs in ground water fromboth influents and effluents in manylocations across the United States.

In the 1986 amendments to the SafeDrinking Water Act, Congress specifiedin section 1412(b)(5) of the Act that:granular activated carbon is feasible for thecontrol of synthetic organic chemicals, andany technology, treatment technique, or othermeans found to be the best available for thecontrol of synthetic organic chemicals mustbe at least as effective in controllingsynthetic organic chemicals as granularactivated carbon.

For all the VOCs except vinylchloride, EPA has identified GAC astechnology that is effective for removingVOCs. PTA is equally effective.

Therefore, these two technologies are"best" for these seven VOCs. PTA ismore effective than GAC for vinylchloride, as noted below.

Vinyl chloride differs from the otherVOCs because it is a gas under typicaltemperature and pressure conditions.Therefore, vinyl chloride is most easilyremoved by PTA treatment. Becausevinyl chloride is a gas and a knownhuman carcinogen, no laboratoryisotherms have been developed by EPAor reported in the literature. However,one investigator reported sporadicremoval of vinyl chloride from groundwater in Florida using GAC (Symons,1978). This investigator also noted thatvinyl chloride was the only one of anumber of related, low molecular weightVOCs to show such an erratic pattern. Amore recent, unpublished study ofground water in Wisconsin (EPA, 1987)showed less erratic removals at a higherempty bed contact time and lower rawwater concentrations. It is difficult tointerpret either of these studies.Therefore, because PTA has beendemonstrated to be extremely effectiveand GAC may, under somecircumstances, exhibit poor or erraticremoval, EPA is not specifying GAC as"best" for the removal of vinyl chloride.PTA, however, is "best" for removal ofthis contaminant.

Also, it should be noted that the dataused to determine removal efficiencieswere based on performance for groundwater. EPA expects that GAC, appliedto surface water, would achieve lowerperformance efficiencies because of thehigher levels of organic carbon found insurface water which cause more rapiddepletion of the capacity of the GAC(ground waters typically have very lowlevels of background organic carbon)(See Reference 2).

In addition to GAC or PTA, there areother technologies which may removeVOCs from drinking water, e.g., resins,powdered activated carbon. However,EPA, has concluded that thesetechnologies are inferior to GAC andPTA for various reasons, e.g., thetechnology is not commerciallyavailable or the removals are lowerand/or less consistent. For a furtherdiscussion of other technologies EPAconsidered, and why they are notdesignated as "best," see EPA'stechnology and cost document(Reference 2).

2. Costs

As noted above, EPA isto set theMCL as close to the MCLG as"feasible," which is defined as "feasiblewith the use of the best technology...which the Administrator finds. . . isavailable (taking costs into

consideration)." Section 1412(b)(5). Inconsidering costs to determine whetherthe "best" technology is "available,"(i.e., BAT), the legislative history of boththe Safe Drinking Water Act of 1974 andthe 1986 amendments indicates that EPAis to consider whether the technology isreasonably affordable by regional andlarge metropolitan public water systems[see H.R. Rep. No. 93-1185, p. 18 (1974)and statement of Senator Durenberger,Vol. No. 132 Cong. Rec. S6287 (daily ed.,May 21, 1986)].

To determine BAT, EPA evaluated thecosts associated with the technologies itconsidered "best," i.e., GAC and PTA.EPA estimates the total costs ofremoving each of the eight VOCs (in1983 dollars) for both GAC and PTAbased on 90-99 percent removal (i.e.,form 0.5 mg/1 to 0.005 mg/1). EPAlooked at these costs for large systems(i.e., systems serving 100,000 to 500,000people], medium systems (i.e., systemsserving 3,300 to 10,000 people), andsmall systems (i.e., systems serving 100to 500 people).. Costs for large to medium systems

range from 10 to 85 cents/1,000 gallonsfor GAC and five to 30 cents /1,000gallons for PTA. Costs are higher forsmall systems; for instance, benzeneremoval using GAC would costapproximately $1.50/1,000 gallons, andremoval using PTA would cost 86 cents/gallon. For concentrations of VOCsexpected in ground waters, CAC canachieve a level of 0.005 /mg/l atreasonable empty bed contact times andcarbon usage rates. This is reflected inthe costs displayed in Table 5. The costsare based on carbon usage rates thatestimate breakthrough at three to sixmonths; however, in a number oflocations GAC has achieved VOC levelsbelow detection for 12 months or longer.The empty bed contact time is reflectedin the capital costs and carbon usagerates in the annual O&M costs. EPAbelieves that the costs incurred by eventhe smallest system size (25-100 people)are reasonable and affordable.(Reference 2).

While most commenters agreed withthe cost estimates presented in theproposal, several claimed that theAgency's treatment cost estimates weretoo low. EPA believes that the range oftreatment cost estimates arerepresentative. The differences betweenEPA's estimates and those presented bythe commenters are due to the uniquesite-specific factors considered'by thecommenters (e.g., variations in costs ofland, zoning requirements for towerheight, housing for columns, and laborand material costs).

Federal Register /'Vol.' 52, No. 130 /' Wednesday, July 8, 1987 /Rules and Regulations

Some commenters stated that theAgency should consider the cost of airpollution control for VOC emissionsfrom packed tower aeration. EPA doesnot believe that it is appropriate tofactor the cost of air pollution controlinto the treatment costs sinceassessments show air emissions to benegligible from aeration treatment ofdrinking water to remove VOCs (SeeRef. 5, Peters and Clark, 1985). Forfurther information on air emissions ofVOCs, see the November 1985 notice (50FR 46911, November 13, 1985).

For contaminants with MCLGs set ata non-zero level (substances incarcinogenicity Group C, D, or E), i.e.,1,1-dichloroethylene, 1,1,1-trichloroethane, and para-dichlorobenzene, EPA has concludedthat the removal costs cited above areaffordable. Therefore, because thesetechnologies meet the treatment criteriaand the costs are reasonable, GAC orPTA are BAT for these threecontaminants. Since these technologiescan easily remove these contaminants tolevels below their MCLGs, it is feasibleto set MCLs equal to the MCLGs. EPAhas set the MCLs accordingly.

For contaminants with MCLGs at zero(substances in either Group A or B], theanalysis is somewhat different becausedetection and achievement of zeroconcentration in principle cannot beachieved. In the MCL-setting process,therefore, EPA evaluates the feasibilityof achieving levels as close to zero asfeasible. Based on the costs and theavailability/performance of treatmentdescribed above, EPA has concludedthat GAC and PTA are BAT (except thatGAC is not BAT for vinyl chloride, sinceit is not the "best" technology).

To determine what level was feasibleas BAT, EPA examined the totalcompliance costs at various levels ofcontamination (as well as the individualcompliance costs summarized above).For all the contaminants with MCLGs atzero, except for vinyl chloride, if theMCLs were set at 0.005 mg/l, EPAestimates that 1300 CWS would need toinstall treatment at a total capital cost of$280 million to achieve compliance. IfEPA set the MCLs at 0.001 mg/l for thesecontaminants, EPA estimates that manymore systems, i.e., a total of 3800, wouldhave to install treatment at a totalcapital cost of $1,300 million to achievecompliance. EPA believes that,considering the efficacy and thenationwide costs associated with thesedifferent levels, as specified in the Act,the costs associated with the additionalremovals, i.e., from 0.005 mg/I to 0.001mg/I, are not warranted. Therefore, theAgency has established MCLs for

trichloroethylene, carbon tetrachloride,1,2-dichloroethane, and benzene at 0.005mg/l.

For vinyl chloride, EPA has set theMCL at 0.002 mg/l. This lower levelreflects the treatment capability of PTAthat would be used to remove vinylchloride, and it is not expected to resultin any increased cost over an MCL of0.005 mg/l. EPA believes that very few,if any, public water systems will need toinstall treatment solely to control vinylchloride. Because systems with vinylchloride present at any level virtuallyalways have one or more of the otherVOCs covered by this rule present atlevels higher than the promulgated MCLfor these VOCs, these systems will betreating their water to comply with theMCLs applicable to those other VOCsand the same treatment (PTA) will alsoremove the vinyl chloride to 0.002 mg/l.

EPA estimates the total compliancecosts to meet the eight MCLs at $300million (total present value costs) and$22.5 million (total annual costs) (SeeRef. 3, "Economic Impact Analysis ofProposed Regulations"). EPA estimatesthe annual cost per family to be $41 peryear for a small system, $12 per year fora medium system, and $3 per year for alarge system.

3. Other FactorsThe other factors EPA examined

support its MCL determinations. Theyare explained below.

Analytical Methods. The Agency alsoexamined the analytical methodsavailable for the measurement ofvolatile organic chemicals in drinkingwater and summarized its findings in theNovember 1985 notice, Based on thisreview, the Agency has determined thatanalytical methods currently existwhich can reliably measure VOCs indrinking water. In addition, EPA hasconcluded that the cost of sampleanalysis at intervals necessary to assuredetection of MCL violation iseconomically feasible for all publicwater systems. Costs are estimated tobe approximately $150 to $200 persample analysis. Further discussion ofavailable analytical methods is includedin the section on compliance monitoring.The MDL is the minimum concentrationof a substance that can be measuredand reported with 99 percent confidencethat the true value is greater than zero.These MDLs are the result ofmeasurements made by a few of themost experienced laboratories undernon-routine and controlled idealresearch-type conditions.

MDLs and PQLs. The MDL is used byindividual laboratories to determine thelaboratory-specific minimum detectioncapabilities. EPA has gathered

information indicating that laboratoriesin general are able to achieve MDLs of0.0005 mg/l or lower with the availableVOC methods (Ref. 1). Specifically,under single-laboratory, idealconditions, the method detection limits(MDLs) of the eight VOCs have beendetermined to range from 0.0002 to0.0005 mg/l.

In the November 1985 proposal, EPAdefined the "practical quantitationlevel" (PQL) as the lowest level that canbe reliably achieved within specifiedlimits of precision and accuracy duringroutine laboratory operating conditions.PQLs thus represent a level consideredto be achievable on a routine basis. Thebasis for setting PQLs is (1) quantitation,(2) precision and accuracy, (3) normaloperations of a laboratory, and (4) thefundamental need (in the compliancemonitoring program) to have a sufficientnumber of laboratories available toconduct the analyses.

The PQL is analogous to the limit ofquantitation {LOQ) as defined by theAmerican Chemical Society. Both theLOQ and the PQL define theconcentration of an analyte abovewhich is the region of quantitation andbelow which is the. region of less certainquantitation. The difference is thatwhere the PQL is an inter-laboratoryconcept while the LOQ is specific to anindividual laboratory. The Agencydeveloped the PQL concept to define ameasurement concentration that is timeand laboratory independent forregulatory purposes. The LOQ andMDLs, although useful to individuallaboratories, do not provide a uniformmeasurement concentration that couldbe used to set standards.

PQLs for the VOCs were determinedbased on the MDL and surrogate testdata. In the past, EPA has estimated thePQL at five to ten times the MDL and, inthe November 1985 notice, EPAsuggested setting PQLs at this generalrange. In the notice EPA used the resultsof inter-laboratory studies to confirmthis estimate. The PQLs based on theselaboratory data are considered a "two-step removed" surrogate for actuallaboratory performance, first becausethey are estimated from anothermeasurement (the MDL) and second,because they are derived fromlaboratory performance under idealcircumstances. Therefore, they do notactually represent the results of normallaboratory procedures, but are a modelof what normal procedures mightachieve. Specifically:

(1) Laboratories receive performanceevaluation samples in which a limitednumber of concentrations are analyzed

I2569925699


and the samples do not have matrixinterferences as might actual samples;

(2) PQLs are based on EPA and Statelaboratory data which are considered tobe representative of the bestlaboratories, but not all laboratories;and

(3) Samples are analyzed undercontrolled ideal testing conditions whichmay not be representative of routinepractice.

For these reasons, the PQL represen'tsa relatively stringent target for routineperformance. EPA expects that the PQLsin this rule will push laboratories toperform at a higher level than theywould otherwise. In the range betweenthe MDL and the PQL, quantitation ofcontaminants can still be achieved, butnot necessarily with the same precisionand accuracy possible at the PQL. Asmeasurements approach the MDL, thereis much less confidence in quantitation.Thus, PQLs set a target performancelevel for laboratories using a specifiedset of precision and accuracylimitations. In this manner, PQLsprovide consistency in implementing aregulatory program, in a practical way,where both quality control and qualityassurance is critical.

Most commenters agreed with thePQL concept; however, several statedthat the PQLs should be verified furtherthrough additional multi-laboratorystudies. For instance, severalcommenters were critical of the PQL forvinyl chloride, stating that the levelshould be based on multi-laboratorydata as opposed to simply being set at avalue of five times the MDL. EPA agreesthat the PQLs should be further verified;as explained in Reference 1, the Agencycollected additional multi-laboratorydata including data on vinyl chloride,and used these data to set the finalPQLs.

One commenter felt that PQLs shouldbe replaced with the LOQ concept asdescribed above. EPA does not agreethat the PQL should be set based uponthe LOQ because the LOQ is dependenton the precision attainable by a specificlaboratory, which can vary from day today-as well as among laboratories.Thus, the LOQ is not designed to assessthe performance of a large number ofgood laboratories; instead, it islaboratory-specific and therefore is notsuitable for setting criteria for nationalstandards.

Some commenters stated thatthe.PQLs were set at too high a level andsuggested 0.001 mg/I, while othersbelieved that:the PQLs were too low. APQL range from 0.02 to 0.04 mg/l forbenzene was suggested by onecommenter. .

EPA disagrees with the comments thatthe PQLs were set at the wrong level;the levels were selected based on multi-laboratory data which confirmed thegeneral rule of five to ten times theMDL. Setting the PQLs at higher orlower levels would not be consistentwith the data. EPA recognizes that manylaboratories have reported data at levelsless than the PQL; however, the Agencydoes not consider the data sufficientupon which to base national standardsconsidering the other data available.Again, PQLs provide for consistency indata quality from a diverse group oflaboratories across the country, andprovide routine performance goals thatmany laboratories must strive toachieve.

As explained in Reference 1, the PQLsare 0.005 mg/l for all the VOCs exceptvinyl chloride. EPA generally based thePQLs upon a laboratory performancecriterion of ±20 percent or 40 percent,depending on the concentration, foreach individual VOC except for vinylchloride which was ±40 percent. Thisprovides a relatively stringentperformance target for laboratories butone that has been demonstrated to beachievable by three-quarters of the"best" (EPA and State) laboratoriesunder evaluation conditions. It isexpected that the remaining laboratorieswill need to upgrade their performancein order to meet this criterion. For vinylchloride, the PQL is 0.002 mg/I (roundedfrom 0.0015 mg/l for the reasonsdiscussed in Reference 1). The PQL of0.002 mg/l recognizes that on the onehand the precision/ accuracy associatedwith measuring vinyl chloride isexpected to be less than for the otherVOCs; but that, on the other hand, vinylchloride is a known human carcinogenof high potency and the risk posed byeach unit of exposure could be higherthan for the other VOCs. Because of thislatter factor, EPA believes it isappropriate to accept slightly lessprecise data in order to seek to obtainmore stringent levels of control.Technical assistance to laboratories thatwish to be certified to analyze vinylchloride is available for EPA-EMSL inCincinnati.

For each VOC, the PQL is equal to orless than the MCL. Therefore,laboratories will be able to reliablydetermine whether systems are incompliance with the MCLs.

Health Risks. EPA examined thetheoretical maximum health risksexpected at various contaminant levels.These health risks include non-cancerrisks, as well as cancer risks. The upper-limit unit risk estimates from the animal,data are derived from a linearized multi-staged nonthreshold extrapolation

model that is currently programmed asGLOBAL 83. Justification for its use ispresented in EPA's Guidelines forCarcinogenic RISK Assessment. Whilerecognizing that alterna':ive statisticalmodeling approaches exist (e.g., one-hit,Weibull, log-probit and logit models,and maximum likelihood estimates), therange of risks described by using any ofthese modeling approaches has littlebiological significance unless data canbe used to support the selection of onemodel over another. In the interest ofconsistency of approach and ofproviding an upper bound estimate forthe potential cancer risk, the Agencyrecommends the use of the linearizedmultistage model. EPA considers thismodel and resulting risk estimates to bean upper-limit value in the sense thatthe true risk is unlikely to be higher andmay be lower. An established proceduredoes not yet exist for making "mostlikely" or "test" estimates of risk withinthe range of uncertainty derived by theupper and lower limit values.

Table 2 presents sample riskestimates calculated at the 95 percentconfidence limit using the multi-stagemodel for the five VOCs which areconsidered known or probable humancarcinogens. EPA's CarcinogenAssessment Group (CAG) calculatedthese numbers based on the assumptionof two liters of water ingested daily overa lifetime of 70 years for a personweighing 70 kilograms (kg). The Agencycalculates these risk estimates so thatthey are not likely to underestimate theactual risks, and are conservativelyused to evaluate "worse case" scenariosfor the purpose of regulatory impactanalysis.

TABLE 2-AN EXAMPLE OF UPPER BOUND LIFE-TIME CANCER RISK (10 -) ESTIMATES FORVOCS CATEGORIZED AS KNOWN OR PROBA-BLE HUMAN CARCINOGENS

Concentration inCompound drinking water (mg/I)

Estimate Rounded*

Tdchloroethylene .................................. 0.026 0.03Carbon tetrachloride ............................. .0027 .0031,2-Dichloroethane ............... .0038 .004Vinyl choide ....... ........... .00015 .0002Benzene .......................................... .012 .01

*Risk levels are best represented by one significant figurebecause ol the imprecise nature of the risk model extrapola-lions.

- calculation using preneoplastic nodules. It preneoplasticnodules were not factored into the risk assessment, theestimated risk at ,10 - is 0.02 mg/I.

As mentioned above, forcontaminants in drinking water, thetarget reference'risk range forcarcinogens is10-4 to 10 -6 and theMCLs EPAis 4romulgating in this noticegenerally fall in this range. EPAconsiders these to be'safe levels and


protective of public health.This issupported by the concept expressed bythe WHO 1984 Guidelines for DrinkingWater Quality, where it selected a 10 -5guideline value, and then explained thatthe application could vary by a factor often (i.e., 10- 4 to 10- .

4. Summary of MCL DeterminationsEPA considers the MCLs determined

by this process to be safe and protectiveof the public health. Even though theMCLGs and MCLs for certainsubstances such as 1,1,1-trichloroethaneand para-dichlorobenzene are relativelyhigher than those for the other VOCs,EPA does not mean to imply thatsystems should allow a drinking watersupply to be contaminated up to thoselevels. Public water supplies shouldalways strive to distribute drinkingwater of the highest quality feasible. Insome cases, other factors such as tasteand odor can be used to limitunnecessary contamination and toassure the overall safety of the water.Although they are not federallyenforceable, EPA intends to publishNational Secondary Regulations forthese and other substances in the futurebased upon aesthetic considerations.The threshold for p-DCB appears to bein the range of 0.01 mg/l. The taste andodor threshold of 1,1,1-trichloroethane isabout 1 mg/l.D. Other Treatment Technologies

As stated in Section 1412(b)(6) of theAct, this regulation does not require theuse of BAT (i.e., GAC or PTA), or anyother technology to meet the MCLs;public water systems may use anyappropriate technology acceptable tothe State that treats all of the water andthat results in compliance with the MCLFor example, there are many aerationtechnologies other than PTA (e.g.,multiple tray aeration, diffused aeration,spray aeration) that remove VOCs andwhich a public water system may wishto install instead of BAT.

In the November 1985 notice, EPAproposed that point-of-use (POU) andpoint-of-entry (POE) technologies not beconsidered BTGA but be consideredacceptable technology to meet MCLs,provided certain conditions were met(50 FR 46916, November 13, 1985). EPAdid not propose POU or POEtechnologies as BTGA because ofdifficulties associated with monitoringcompliance and assuring effectivetreatment performance in a mannercomparable to central treatment;furthermore, POU devices only treat thedrinking water at a single tap. Inaddition to potential exposure viaingestion at untreated taps, POU devicesdo not treat the exposure Introduced

through indoor air transport (e.g., fromshowers or dermal contact). In addition,these devices are generally notaffordable by large metropolitan watersystems, which is one of the criteria forsetting BAT.

In the November 1985 notice, theAgency discussed its proposal to notallow PWSs to use bottled water forcompliance or to meet conditions ofvariances and exemptions. Publiccomments pointed out that bottled watermay, in a few cases, be the onlyavailable "treatment technique" for thethe smallest systems. The Agencyrestated in its April 1987 notice thatbottled water was not an acceptablemeans of meeting the MCL requirementson a permanent basis since it does notprovide the same level of protection ascentral treatment (i.e., persons maychoose not to drink bottled water) andbottled water might allow significantexposure to water which does not meetthe drinking water standard duringshowering and other applications.However, in that notice, EPAproposed that bottled water be allowedas an interim measure to prevent anunreasonable risk to health during thetime between detection of an MCLviolation and achievement ofcompliance; it is emphasized thatprovision of bottled water during thisinterim period does not bring the PWSinto compliance with the MCL; bottledwater does, however, provide anacceptable source of water to drinkduring the interim period. In a futurenotice, EPA will further assess theadvisability of allowing some NTNCWSand very small systems to use bottledwater to meet the MCL requirements.

The majority of commenters agreedthat POU/POE devices and bottledwater should not be considered BAT,and that the NPDWR should not allowtheir use for compliance with MCLs, dueto difficulties in controlling installation,maintenance, operation, repair, andpotential human exposure via untreatedtaps. However, other commenters statedthat POU/POE devices and bottledwater should be considered BAT orallowed for compliance, as thesetechnologies were often more cost-effective for some small systems thancentral treatment.

In this final rule, POE and POUdevices are not designated as BATbecause: (1) It is significantly moredifficult to monitor the reliability oftreatment performance and to controlthe operation of POE and POU devicesin a manner comparable to centraltreatment; (2) these devices aregenerally not affordable by largemetropolitan water systems; and (3) in

the case of POU devices, not all water istreated. In addition, under this rule, POUand bottled water are not consideredacceptable means of compliance withMCLs. These devices do not treat all thewater in the home and could result inhealth risks due to exposure tountreated water. Consequently, POUdevices and bottled water are onlyconsidered acceptable for use as interimmeasures, e.g., as a condition ofobtaining a variance or exemption, toavoid unreasonable risks to healthbefore full compliance be be achieved.Under this rule, however, POE devicesare acceptable means of compliance,because POE provides drinking waterthat meets the standards throughout thehome. These devices may be cost-effective for small systems or non-transient non-community water systems(for which these devices would often beessentially the same as centraltreatment), although operationalproblems may be greater than forcentral treatment in a communitysystem.

The SDWA requires EPA to establishnecessary conditions for use oftreatment that will assure protection ofpublic health. Specifically, section1401(1) of the Act states that primarydrinking water regulations are tocontain "criteria and procedures toassure a supply of drinking water whichdependably complieswith . . . maximum contaminant levels,including quality control and testingprocedures to insure compliance withsuch levels and to insure properoperation and maintenance of thesystem." Accordingly, this rule imposesthe following conditions on thosesystems that use POE for compliance:

(1) Central Control. The public watersystem will be responsible for operatingand maintaining all parts of thetreatment system (i.e., the treatmentdevice). Central ownership is notnecessary, as long as the public watersystem maintains control of theoperation of the device. Central controlis appropriate and necessary to ensurethat the treatment device is kept inworking order.

(2) Effective Monitoring. Asmonitoring the quality of a PWS'drinking water is a central part ofensuring compliance with any NPDWR,the public water system must develop aplan and obtain State approval for amonitoring plan before it installs thePOE devices. Because POE devicespresent a fundamentally differentsituation than central treatment, aunique monitoring plan must bedeveloped. This monitoring plan mustensure that the POE devices provide

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health protection equivalent to centralwater treatment. Equivalent means thatthe water would meet all Primary andSecondary Drinking Water Standardsand would be of acceptable qualitysimilar to water distributed by'a welloperated central treatment plant. Inaddition to the VOCs, monitoring must'include physical measurements andobservations, such as total flow treatedand the mechanical condition of the:treatment equipment.

(3) Application of EffectiveTechnology. There are no generallyaccepted standards for the design andconstruction of POE devices, and thereare a variety of POE designs 'available.Therefore, the State must requireadequate certification of performance,field testing, and, if not included in thecertification process, a rigorousengineering design review of each typeof device. Certification can be! done bythe State or by a third party acceptableto the State.

(4) Maintenance of theMicrobiological Safety of the Water.The design and.application of POEdevices must consider the tendency forincreases in bacterial concentrations inwater treated with activated carbon andsome other technologies. It may benecessary to use frequent backwashing,post-contactor disinfection, andmonitoring to ensure that themicrobiological safety of the water isnotcompromised. EPA considers thiscondition necessary because *disinfection typically is not providedafter point-of-entry treatment as isnormal is used in a central treatmentplant.

(5) Protection of All Consumers. Everybuilding connected to a public watersystem must have a POE deviceinstalled, maintained, and adequatelymonitored. If the building is sold, therights and responsibilities of the utilitycustomer must be transferred to the newowner with the title.

E. Analytical Methods and ComplianceMonitoring Requirements

1. Analytical MethodsIn the November 1985 notice, the

Agency proposed the use of threeanalytical methods that it consideredeconomically and technologicallyfeasible for monitoring compliance withthe VOC MCLs. These methods were:

(1) EPA Method 502.1, "VolatileHalogenated Organic Compounds inWater by Purge and Trap Gas.Chromatography."

(2) EPA Method 503.1, "'VolatileAromatic and Unsaturated OrganicCompounds in Water by Purge and TrapGas Chromatography."

.(3) EPA Method 524.1, 'VolatileOrganic Compounds in Water by Purgeand Trap Gas Chromatography/MassSpectrometry."

Capillary Column Techniques. Somecommenters recommended the use ofcapillary column techniques for VOCanalyses. The Agency evaluatedcapillary column methodology andagreed that they are available. Somecommenters also recommended the useof detectors in series to analyzepurgeable halocarbons and aromaticssimultaneously. The Agency agrees andhas developed Method 502.2, whichprovides for the use of detectors inseries, and proposed capillary columnanalytical methods at 52'FR 12879 (April17, 1987). This final rule includes thecapillary column.methods as approvedanalytical methods:

(1) Method 524.2, "Volatile OrganicCompounds in Water by Purge and TrapCapillary Column Gas Chromatography/Mass Spectrometry."

(2) Method 502.2, "Volatile OrganicCompounds in.Water by Purge and TrapGas Chromatography withPhotoionization and ElectrolyticConductors in Series."'

Disapproval of the 600 SeriesMethods. In addition, on May 27, 1986(52 FR 19076), EPA requested commenton whether to approve the 600 seriesmethods (i.e., EPA's analytical methodsfor detecting volatile synthetic organiccompounds in wastewater, Methods 601,602, and 624 in 40 CFR Part 136) forcompliance monitoring since a numberof comments to the November 1985notice suggested they be approved aswell.

EPA has evaluated the comments anddetermined that the 600 series methodsare technically very similar to the 500series methods (e.g., the analytescovered, and the analytical columns,detectors, and chromatographicconditions are the same). However, EPAhas determined that the methods are notinterchangeable for various reasons.'First, their analytical objectives aredifferent. The 500 series methodsemphasize detectability at low levelswhile the 600 series methods do notfocus on measurements near the MCLs(the sample volume is 5 ml in Method624 versus 25 ml in Method 524.1).Second, the specific quality controlrequirements that must be met for the500 series and the 600 series methodsare different. The performance criteriaspecified in the 500 series methods are

* more stringent than those in the 600series methods. For example, the 500series methods include a requirementthat laboratories analyze quality control

- standards within 60 and 140 percent ofthe expected value, while the

established performance criteria of the:"600 series methods,, While they aredifferent for eaih 'analyte, are wider.Therefore,'EPA hasniot included the 600series methods in this regulation a'sacceptable"analytical methods forcompliance monitiing because thesemethods are not designed to maximizedetectability a.t low levels and do nothave as stringent performance criteria,as do the 500 se'ries methods.

2. Compliance-Monitoring RequirementsThis final. rlerequires compliance

monitoring, to determine' Whether publicwater systems are distributing drinkingwater that meets the MCLs. The Agencyhas determined that the VOCs are TierII contaminants in the three-tieredscheme presented in the Phase IIAdvance Notice of ProposedRulemaking, published on October 5,_1983 (48 FR 45502), and further discussedin the November 13, 1985, VOCs MCLproposal (50 FR 46902). Tier IIcontaminants are.those which are ofsufficient concern to warrant nationalregulation (i.e., MCLs or treatmenttechnique requirements) but whichoccur with limited frequency, thereforejustifying flexible national minimummonitoring requirements to be appliedby. the State..

EPA presented three options in theNovember 1985 notice for VOCcompliance monitoring requirements (50FR 46919). EPA proposed option 2 for thereasons stated in that proposal. Thisoption consisted of phasing in themonitoring requirements over a four-year period based on the size of the

* population-served by the public watersupply sys.tem..Specifically:(1) Ground-water systems would be.

required to take one sample per entrypoint to the distribution system. Surfacewater systems would sample at pointsrepresentative of each source in thedistribution system.

(2) The initial sampling to determinecompliance would consist of one sampleevery 3 months per source for a year forboth surface and ground-water systems;the State would have the discretion toreduce the number of initial samples forground-water systems if no VOCs weredetected in thatinitial sample. Follow-up actions when VOCs are detected,such as confirmation samples, would beleft to the discretion of the State.Monitoring would be phased in overfour years with large systems first.

(3) All systems would have to conductrepeat! monitoring. The repeatmonitoring frequency would be basedon the initial monitoring results (i.e.,whether VOCs were found) and on thevulnerability of the system to VOC


contamination. EPA proposed aminimum repeat monitoring frequency ofonce every five years for systems notconsidered vulnerable based on theprocedure established in the initialsample (i.e., each system samples onceevery 3 months for a year. If no VOCsare found and the system is notvulnerable to contamination, the Statemay reduce the sample to that taken inthe first quarter. EPA also proposed thatthe State be required to confirm thevulnerability status of systems once ayear).

(4) Monitoring for vinyl chloridewould only be required by ground-watersystems detecting one or morechlorinated two-carbon VOCs (e.g.,trichloroethylene, 1,2-dichloroethane,1,1,1-trichloroethane, and 1,1-dichloroethylene) for the reasonsdetailed in the proposal (50 FR 46919).

(5) "Grandfathering" of previouslycollected data, of acceptable analyticalquality (i.e., comparable to thoselaboratories that have interimcertification), including sample analysisduring Federal or State surveys, wouldbe allowed for compliance monitoringpurposes.

Appendix A to the November 1985notice contained guidance fordetermining the vulnerability of publicwater systems to contamination byVOCs. The general criteria suggestedwere: (1) Population; (2) nearby use,storage, or disposal of VOCs; (e.g.,proximity to landfills and RCRA sites);and (3) water source protection.

EPA encouraged the States and thePWSs to analyze their watersheds everythree years by conducting a sanitarysurvey, EPA also encouraged systems toperform a comprehensive analysis todetermine the presence of the eightVOCs proposed in the notice, theunregulated contaminants listed in thisnotice (in Section III.J), and as many aspossible of the seventy-five othercontaminants for which NPDWRs are tobe promulgated by June 1989 as requiredby the SDWA. The State could use theresults of this analysis, in part, todetermine requirements for monitoringfrequency for the eight VOCs.

EPA received a large number ofcomments on the proposed monitoringrequirements. Most commenterssupported the phase-in approach, asproposed. Other commenters stated thatthe costs of monitoring were too highand that the State should have evenmore discretion to determine whichsystems should monitor and how often.Some commenters recommended thatconsecutive water companies not berequired to sample, that a monitoringexemption be allowed for small systems,and that EPA reduce the required

sampling for systems with wells thatonly operate a few months a year.Othercommenters recommended that thevulnerability' assessment be included aspart of the sanitary survey which isconducted every three years under thecurrent NPDWR for coliforms, ratherthan annually. Commenters supported.the provisions for "grandfathering"previ'ous data in lieu of new data for theinitial round of monitoring.

In this final regulation, EPA hasretained the majority of the monitoringrequirements described in the preferredoption (Option 2). In the final regulation,EPA is requiring that all communitywater systems and NTNCWs conduct aninitial round of monitoring to determinethe extent of contamination of watersupplies. All size systems must monitoras the occurrence data collected by EPAindicate that systems of all sizes havedetected VOCs at relatively highconcentrations, sometimes withoutapparent sources of contamination. Ingeneial, the likelihood of contaminationincreases with population, since areas oflarge commercial or industrial activityare often located in large populationcenters. The Ground Water SupplySurvey of 1982 (Ref. 7) found that 16percent of the smaller systems (<10,000people) and 28 percent of the largersystems (>10,000 people) haddetectable VOCs .EPA believes thatphasing in the monitoring requirementsby system size is reasonable because ofthe greater vulnerability of the largesystems and because these systems canmore easily handle the monitoring costsassociated with this regulation. Inaddition, phasing in the requirementsover a four-year period will allow theanalytical laboratories to develop thecapability to handle the additionalsamples. This is consistent withprevious regulatory actionsimplementing the Safe Drinking WaterAct (eg., trihalomethanes).

EPA has modified the samplinglocations for surface water systems suchthat samples can be taken aftertreatment from entry points to thedistribution system taps that arerepresentative of each source.

EPA investigated the feasibility ofcompositing samples for VOC analysesin an effort to reduce the monitoringcosts. Sample-compositing could then beused as a screening test to determinewhether samples from multiple samplingsites may be contaminated by VOCs.EPA investigated composites of 5different samples since a concentrationin the original sample above the PQL(and the MCL for some VOCs) shouldstill be detectable but not quantifiable ina composite sample resulting from suchdilution, for example, if one of the five

samples were contaminated at 0.005mg/I and the other four were zero. .Reanalysis of each sample would be.required if VOCs were detected in thecomposite sample. The experimentsconducted by EPA were done todetermine whether sample-compositingwould work for the VOCs (i.e., whetherVOC losses could be kept to aminimum), and to determine thetechnique most appropriate to minimizeVOC losses.

The experiments conducted involvedthe preparation of composite samplesfor GC and GC/MS analyses.Theprocedures investigated for each type ofanalysis were different because of thedifference in sample size (5-ml samplepurged for GC analyses; 25-mI samplefor GC-MS analyses). The compositingtechnique that worked best for GCanalyses involved the addition of five 5-ml samples to a 25-ml glass syringe and,after mixing, drawing out a 5-ml aliquotfor analysis. The mixing should be donewith the sample cooled at 4 C tominimize VOC losses. Data collected forfive replicate samples demonstratedexcellent recovery for all compounds(95-100 percent) with good precision,generally 3-5 percent relative standarddeviation. The recommendedcompositing technique for GC/MSanalyses involves the injection of 5 ml ofeach sample directly into the purgedevice. For most components, recoverieswere greater than 85 percent with goodprecision, generally between 3-5 percentrelative standard deviation (Reference1).

Based on this information, proceduresfor compositing samples are included inthe regulations. Several points arebriefly addressed below. Samples are tobe collected from each source andshipped to the laboratory where theywill be composited. Compositing is notdone in the field. Public water systemsand States that collect samples must beaware that there are some potentialproblems that should be kept in mindwhen they composite samples. It isdesirable that sampling schedules bearranged in a manner that provides forcollection of all samples to becomposited the same day. Samplepreparation and analysis must takeplace within the maximum holding timeof 14 days. The samples collected areshipped to the laboratory where theanalyst will prepare a composite samplefrom a series of discrete samples. Thisadditional sample preparation stepprovides more opportunity for theintroduction of recordkeeping errors soadditional care must be taken. EPArecommends that all samples becollected in duplicate to provide an

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additional sample in case VOCs aredetected in the composite sample. Thiswould avoid the need to resample ateach sample site to determine whichsite(s) may be contaminated. If VOCsare detected in the composite sample,the original samples cannot bereanalyzed because of head spaceproblems created when the first aliquotwas taken. Reanalysis must beconducted for each of the duplicatesamples, provided the maximum storagetime of 14 days has not been exceeded.Resampling must be done immediatelywhere one or more VOCs are detected ifno duplicates are available.

The greatest limitation of compositingsamples from different sources is thatthe analytical results will not actuallyprovide a measurement of what is in thewater if the composite sample turns outto be negative. It is possible that someVOCs may be present at trace levelsand will not be detected in a compositesample. Therefore, sample-compositingis not the preferred approach but onethat can be used when monitoring costsadd a significant economic burden, withrecognition of its limitations.

Confirmation samples of positiveresults can be required by the State:results of confirmation samples must beincluded in the quarterly average alongwith the initial sample. States, however,have discretion to delete obviousanalytical errors in the initial orconfirmation samples. In addition,States have discretion to requireadditional monitoring samples; results ofall samples must be included in eachrespective quarterly average (except asnoted above for obvious errors).

EPA modified some of the monitoringrequirements it proposed in theNovember 1985 notice to address theconcern of many commenters regardingmonitoring costs. These changes aresummarized below and furtherdiscussed in the Methods andMonitoring document (Ref. 1).

(1) The number of samples requiredfor ground and surface water systemshas been reduced from the numberproposed. The rule allows compositesamples of multiple sampling sites (up tofive samples), resulting in lower costs.When monitoring costs would create anunacceptable financial burden, Statesthat conduct the monitoring themselvescan composite samples from differentsystems. This may be particularlybeneficial for monitoring non-transientnon-community water systems. Asproposed, under the final rule, if VOCsare detected in a composite sample,follow-up analysis is required for eachsource (see discussion of compositesamples).

(2) The repeat compliance monitoringrequirements for those systems that theState determines are vulnerable but inwhich no VOCs were found in the initialsample, are based upon system size (seeTable 4).

(3) For systems finding two-carbonVOCs, vinyl chloride analysis isrequired. If vinyl chloride is not detectedin the initial sample States can reducemonitoring frequencies to once everythree years for vinyl chloride.

As for comments recommending thatEPA reduce sampling for systems withwells that only operate a few months ayear, the Agency believes that any suchreduction is appropriate. Under this finalrule monitoring is required for all wells,including backup wells, only when theyare being used. For example, fourquarterly samples would not be requiredfor wells that are only used for say twomonths per year; however, a sampleeach quarter that the wells operatewould be needed.

The Agency agrees with therecommendation that the State make avulnerability assessment once everythree years rather than every year asproposed. In addition, EPA believes thatthe State should make a vulnerabilityassessment (<500 connections) everyfive years only. These changes arereasonable because it is unlikely thatsignificant undetected changes wouldoccur in the vulnerability of a systemsufficient to result in sufficient VOCcontamination within a one- to two-yeartime period. The final rule reflects thesechanges.

EPA also proposed the followingmethod for determining compliance:

(1) All quarterly compliance sampleswould be collected on the same day andanalyzed according to procedurespromulgated in this rule.

(2) Compliance with the MCL wouldbe computed by running arithmeticalaverage of the past four quarterlysamples.

(3) Compliance would be determinedfor each sampling location; if water atthat location was above the MCL, theentire system would be deemed out ofcompliance and public notice would besent to all customers served by thesystem unless there was no inter-mixingof source waters in distribution.

EPA received a number of commentson the proposed method of determiningcompliance. Many commenterssupported the methods, while othercommenters believed that only thatportion of the system exceeding theMCL should be considered out ofcompliance and that public notificationshould be limited to the affectedconsumers. EPA believes that it is often

not possible to determine the specificsubpopulation of consumers receivingwater from a specific part of a watersystem, due to mixing of waters andchanges in water feed pattern. However,it is recognized that certain systems mayhave a clearly definable distributionsystem from a source with nointerconnections to any other source. Toaccommodate these different situations,EPA is promulgating the requirementsfor determining compliance and publicnotification as proposed, except that theState may determine that only onesegment, i.e., the affected part of apublic water system, is out ofcompliance and limit public notificationto that one segment.

EPA received a number of commentssuggesting that monitoring data fromfurther back than the proposed threeyears be allowed in the "grandfather"provision. Since the 1986 Amendmentsto the SDWA allow use of data forunregulated contaminants back toJanuary 1, 1983, EPA feels it appropriateto allow States discretion to also usemonitoring data for the 8 VOCs back tothat date. If a system is judged to be notvulnerable, the previous monitoring datacan be used to represent the first roundof monitoring. In addition, States canuse the results of EPA's Ground WaterSupply Survey for systems with singlesources in the same manner; only singlesources are appropriate because EPAsampled from points in the distributionsystem during the survey.

In conclusion, the final monitoringrequirements for determination ofcompliance with the VOC MCLs are asfollows:

(1) All CWS and NTNCW systemsmust monitor every three months for ayear. The running average willdetermine compliance. If a system is notclassified as "vulnerable" and the firstquarterly sample does not detect VOCs,the State may waive the requirement foradditional sampling.

The State may also reduce the totalnumber of samples by the use ofcomposite samples of multiple entrypoints (up to five entry points persample) if the composites reflectoperating characteristics. If VOCs aredetected in a composite, follow-upsampling is required at each entry pointincluded in the composite. Thisrequirement will be phased in based onthe size of the population served by thesystem as follows:

System size Begin no laterthan

> 10 ,000 ...................... : .....................................J an. 1, 1988.3,300 to 10.000 ................................................ Jan. 1, 1989.


System size Begin no later

< 3.3 , 0 .............................................................. Jan. I, 1991.

(2) Ground-water systems mustsample at each entry point which islocated after any treatment to thedistribution system every three months.

(3) Surface water systems may sampleat points in the distribution system thatare representative of each source or ateach entry.point to the distributionsystem which is located after anytreatment. The minimum number ofsamples is one sample per source, perquarter for one year. Composite samplesrepresentative of up to five sources areallowed. If VOCs are detected in thefirst or any subsequent sample, follow-up monitoring is required as specified bythe State.

(4) Additional samples, when requiredby the State, are to be taken at eachentry point that was included in thecomposite sample. If it is possible todetermine from the follow-up sampleswhich entry point(s) is out of

compliance, then only that entry point(s)need be sampled unless the Statedetermines that other entry points arevulnerable.

(5) Monitoring for vinyl chloride isrequired only for ground water systemswhich detect another chlorinated two-carbon VOC (trichloroethylene, 1,2-dichloroethane, 1,1,1,-trichloroethane,1,1-dischloroethylene,tetrachloroethylene, cis-1, 2-dichloroethylene, or trans-1, 2-dichloroethylene).

(6) All systems to which theregulations apply are required toconduct repeat monitoring except forsurface water systems that the State hasnot classified as vulnerable and did notdetect any VOCs in the first round ofsampling. The frequency of suchmonitoring will be based on priormonitoring results, the volunerability ofthe system, and for those cases whereVOCs have not been detected but thesystem is vulnerable, by system size.

(7) These requirements aresummarized in the table below:

TABLE 3.-SCHEDULE OF REPEAT MONITORING REQUIREMENTS

Status Ground water Surface water

VOCs are not detected * in the Repeat at least every 5 years ........... State discretion.first or any subsequent sampleand the system is not vulnera-ble.

VOCs are not detected andsystem is vulnerable:

Systems >500 connections... Repeat every 3 years ........... Repeat every 3 years.Systems <500 connections .... Repeat every 5 years ......................... Repeat every 5 years.

VOCs detected in any sample ........ Quarterly .............................................. Quarterly.

IMust sample for four consecutive quarters.*Detected is 0.0005 mg/I.

(8) States must certify thevulnerability status of systems at leastevery three years (five years for smallersystems (i.e., 4500 connections).

(9) States have the discretion to:Require confirmation samples forpositive results,

Reduce the repeat monitoringrequirements for systems detectingVOCs, but at levels consistently lessthan the MCL, from quarterly samplingto no less than annual sampling after abaseline of data is developed during atleast a three-year period,

Allow the use of monitoring datacollected after January 1, 1983, in lieu ofnew data for the first sample if the dataare of an acceptable quality and willprovide information equivalent to thatrequired in the rule.

(10) Compliance with the MCL will bebased upon a running annual average of

quarterly samples for each samplinglocation (i.e., the previous four quarterlysamples). If the annual average for anysampling location is above the MCL, thesystem is out of compliance, publicnotification of the system's customers isrequired.

If any one quarterly sample wouldcause the annual average to beexceeded, the system is out ofcompliance as of that quarter. Forexample, if the first quarterly sampleexceeded four times the MCL, thesystem would be out of compliance. Theintent of this provision is to provideearly notification of potential healthrisks.

If the State reduces the monitoring toone sample, the compliancedetermination is based upon that onesample.

F. Laboratory Approval

EPA's existing rules in 40 CFR 141.28require that analyses for compliancemonitoring purposes be conducted onlyby State-approved laboratories.Laboratories wishing to obtain approvalfor conducting VOC analyses mustsuccessfully analyze performanceevaluation samples within the limitsestablished by EPA and meet otherrequirements. The acceptance limits forlaboratory approval are derived fromthe performance evaluation study data,i.e., the Water Supply Study series.

EPA requested comment on the use ofa "plus or minus percent of true value"approach for setting performancecriteria (i.e., acceptance limits). Mostcommenters supported the use of a "plusor minus percent" approach to deriveacceptance limits over generating themfrom study statistics based upon 95percent confidence limits. Somecommenters believed, however, that thespecific acceptance limits proposedwere too strict and there would be aninsufficient number of laboratoriesavailable that could meet suchstandards. EPA disagrees with thiscomment because the most recent watersupply performance evaluation studyshowed that about 85 percent of all datasubmitted to EPA and State laboratoriesand about 70 percent of the otherparticipating laboratories were withinthe proposed acceptance limits. Theseresults compare favorably with otherregulated contaminants where, evenafter years of experience, only 80-85percent of all the data submitted arewithin the acceptance limits for eachstudy. A specific example is thetrihalomethanes, where about 85 percentof the data submitted by EPA and Statelaboratories and about 75 percent of thedata submitted by otherparticipatinglaboratories are within the establishedlimits. The actual percentage variessomewhat from study to study.

The acceptance limits were proposedto be ±40 percent of the true value forconcentrations less than 0.010 mg/l, and±20 percent of the true value forconcentrations of 0.010 mg/I or abovefor all of the VOCs except vinylchloride. More recently, data fromWater Supply Study No. 17, at 51 FR19077 (May 27, 1986) indicate that mostof the better laboratories tested cansuccessfully analyze performanceevaluation within the proposedacceptance limits. EPA consideredlowering the acceptance limits for theseven VOCs to ±20 percent (excludingvinyl chloride). However, very fewlaboratories would be able to performwithin these limits for all seven of the

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VOCs. Only three out of eighteenlaboratories were able to aralyze sixout of seven VOCs withip chese limits inWater Supply Study #17. Therefore, inthe final rule, the acceptance levels are±20 percent of the true value forconcentrations of 0.010 mg/l or above,and ±40 percent of the true value forconcentrations below 0.010 mg/l forseven VOCs (trichloroethylene, carbontetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethane, benzene, 1,1-dichloroethylene, and p-dichlorobenzene).

For vinyl chloride, the finalacceptance limits are based initially on±40 percent of the true value at alllevels. This is because the availabledata support acceptance limits of ±40percent and do not support acceptancelimits of ±20 percent for this compound.EPA may modify the laboratoryperformance requirements for all VOCsas new information becomes available.

Even the best laboratories may not beable to analyze all the VOCs within theacceptance limits 100 percent of thetime. Random errors are likely to occurin any large data generation activity.EPA has evaluated data from recentperformance evaluation studies todetermine how many analytes EPA andState laboratories were able to analyzewithin the acceptance limits. Thenumber of analytes within theacceptance limits varies from laboratoryto laboratory. EPA evaluated data fromWater Supply Study #17 for EPA andState laboratories that analyzed for alleight VOCs. The data indicate that 15out of 18 laboratories (or 83 percent ofthe laboratories) were able to analyze atleast 6 out of 7 VOCs (excluding vinylchloride) at concentrations of 0.004 mg/lor above within the acceptance limits,while only 7 of these laboratories (or 39percent of the laboratories) were able toanalyze all 7 VOCs. For very low levels(<0.004 mg/l) greater failure rateswould result. When the highestconcentration of p-dichlorobenzene(0.776 mg/i) was not considered, 15laboratories were still able to analyze atleast 6 out of 7 VOCs within theacceptance limits, while the number oflaboratories that were able to analyzeall 7 VOCs increased to 12 (or 67 percentof the laboratories). For vinyl chlorideonly 8 out of 18 laboratories (or 44percent of the laboratories) were able toanalyze all three levels within the ±40percent acceptance limits. When thelowest concentration (0.0015 mg/I) wasnot considered, the number oflaboratories within the acceptancelimits increased to 13 out of 18 (or 72percent of the laboratories).

EPA also evaluated preliminary datafrom Water Supply Study #20 todetermine whether this study supportsthe results from the Water Supply Study#17. Two samples were offered in thisstudy to those laboratories wishing toobtain conditional approval for VOCs.One sample contained the eight VOCsfor which MCLs are being set in thisnotice. The second sample contained 4of the 8 VOCs plus other Section 1445unregulated VOCs. Excluding vinylchloride, there were a total of 11responses for the 7 VOCs (7 from thefirst sample and 4 from the secondsample). The results are summarized inTable 4 for a total of 44 EPA and Statelaboratories.

TABLE 4.-ANALYSES WITHIN THE ACCEPTANCELIMITS OF ELEVEN VOC SAMPLES

Num- Per-Acceptable data be of cent oflabors- labora-tories tories

1l out of 11 ..................................................... a is10 out of 11 ............................. - 22 509 out of 11 ...................................................... 31 70a outof 11 ...................................................... 36 82<8 out of II ............................................... 8 18

Taking the data from the first samplefor the seven VOCs, 36 out of 44laboratories (or 82 percent of thelaboratories) were able to analyze atleast 6 out of 7 VOCs within theacceptance limits, while only 22 out of44 (or 50 percent of the laboratories)were able to analyze all seven VOCs.These results are similar to the resultsobtained in Water Supply Study #17 forthe 7 VOCs.

Twenty-nine out of the 44 laboratories(or 66 percent of the laboratories) wereable to analyze vinyl chloride within the±40 percent limits. These results aresimilar to the results obtained in WaterSupply Study #17 when the lowestconcentration (0.0015 mg/l) was notconsidered.

Based on the results obtained inWater Supply Study #17 (which aresupported by preliminary results fromWater Supply Study #20), EPAconcluded that it is reasonable to expectthat laboratories meet the acceptancelimits in § 141.24(g)(11) for at least 6 outof 7 of the VOCs to receive conditionalapproval. Therefore, the Agency willprovide conditional approval of VOCanalysis to laboratories that meet thefollowing requirements:

(1) Use approved analytical methodsas specified in §§ 141.24[g)(10) and141.40(g);

(2) Are approved for THMs analysis;and

(3) Perform within the acceptancelimits for at least 6 of the 7 VOCs(excluding vinyl chloride).

In addition, special conditionalapproval will be granted separately tolaboratories wishing to analyze for vinylchloride if they meet (1) and (2) above,and are able to perform within theacceptance limits for vinyl chloride atall levels.

The above performance criteria applyspecifically to laboratories thatparticipated in Water Supply Study #20.These requirements will apply toconditional approval until such a timewhen EPA evaluates additional WaterSupply Study data and develops finalcertification criteria. States that providetheir own performance evaluationsamples instead of EPA samples mustuse testing procedures equivalent toWater Supply Study #20 and must applythe same requirements, as describedabove, to grant conditional approval tolaboratories.

G. Variances and Exemptions

1. Variances

The conditions for granting a variancefrom an NPDWR are specified in Section1415(a)(1)(A) of the Safe Drinking WaterAct. According to this provision of theACT, EPA or a state which has primaryenforcement responsibility (i.e., theprimacy agent) may grant variancesfrom MCLs to those public watersystems that cannot comply with theMCLs because of characteristics of thewater sources that are reasonablyavailable. A variance may only begranted to those systems which haveinstalled best available technology,treatment techniques, or other meanswhich EPA finds are available (takingcost into consideration); in this noticethese treatment techniques will bereferred to collectively as BAT.Furthermore, before a State may grant avariance, it must find that the variancewill not result in an unreasonable risk tohealth. The level representingunreasonable risk to health for each ofthe VOCs will be addressed in theproposal addressing the next 40contaminants required to be regulatedunder the SDWA by June 1988. Theproposal is scheduled for the Fall of1987. In general, the unreasonable riskto health level would reflect acute andsubchronic toxicity for shorter-termexposures and high carcinogenic risks(as calculated using the linearized multi-stage model in accordance with theAgency's risk assessment guidelines) for.long-term exposures.

Under Section 1413(a)(4), States thatchoose to issue variances must do so


under conditions, and in a manner,which are no less stringent than EPAallows in Section 1415. Of course, aState may adopt standards which aremore stringent than the EPA standards.

Best Available Technologies forVariances. In the November 1985 notice,EPA proposed two technologies as thebest technologies generally available(BTGA) for the treatment of VOCs:packed tower aeration (PITA) andgranular activated carbon (GAC). Thepublic comments that EPA receivedsupported this finding. The 1986amendments to the SDWA changed thetechnology standard for drinking watertreatment from BTGA to best availabletechnology (BAT). After carefullyreexamining the proposed rule in light ofthe 1986 amendments, the Agency hasdecided that packed tower aeration orgranular activated carbon are also BATfor variance purposes (except for vinylchloride, for which BAT is only packedtower aeration); this decision is basedupon the factors discussed in Section IIof today's preamble.

Under Section 1415(a)(1](A), EPA'sdetermination of BAT for variances mayvary from BAT for setting MCLs underSection 1412 based on the number ofpersons served by a particular watersystem, the physical conditions relatedto engineering feasibility, and the costsof compliance. With respect to smallsystems, there are no engineeringaspects of these two technologies whichwould indicate that EPA should specifydifferent BATs for variances, since VOCremoval rates, operational feasibility,and equipment availability do notprevent application to even the smallestsystems. In fact, both technologies arecurrently commercially available insizes that can treat a single home, a few(e.g., 15) homes, or larger size systems.Therefore, EPA has determined that itsselection of packed tower aeration andgranular activated carbon as BAT neednot be varied due to system size, orphysical characteristics, and that thesetechnologies are BAT for all publicwater systems.

Costs Considerations in ApplyingBAT to Small Systems. The Agencybased its decision to designate packedtower aeration and granular activatedcarbon as BAT under Section 1415 forall size systems in part on the followinganalysis of small system costs. Table 3displays the costs of 99 percentremovals of the eight VOCs for thesmallest system size (25-100 persons or13,000 gallons per day) using PTA orGAC. (See Ref. 2 for a more detaileddiscussion.) The costs of treatment forthe very small size category (25-100persons or 13,000 gallons per day) range

from 70 cents per thousand gallons forremoval of trichloroethylene by GAC to204 cents per thousand gallons forremoval of para-dichlorobenzene byPTA. On an annual basis, this might

increase the average small systemresidential water bill by about $70 peryear to remove trichloroethylene and$200 per year to remove 1,2-dichloroethane.

TABLE 5.-ESTIMATED COSTS OF REMOVING VOCS FROM DRINKING WATER

USING PACKED TOWER AERATION OR GRANULAR ACTIVATED CARBON FOR

THE SMALLEST SYSTEM SIZE*

[Assuming 99 percent removal from 0.5 mg/1 to 0.005 mg/1]

PTA GAC

Chemical c/ c/Capital Annual 1,000 Capital Annual 1,000

0& M gallons 0& M gallons

TCE .......................................................... $58,000 $800 169 $13,000 $1,600 70C. Tet ...................................................... 52,000 700 162 13,000 2,000 791,2-DCA ................................................... 62,000 1,300 202 13,000 330 106V.C ........................................................... 48,000 600 148 NA NA NA1,1-DCE ................................................... 50,000 600 154 13,000 1,600 70Benzene .................................................. 56,000 1,000 180 13,000 5,500 1531,1,1-TCA ................................................ 50,000 700 156 13,000 3,500 110p-DCB ...................................................... 63,000 1,300 204 13,000 1,700 72

*Cost are in 1983 dollars. Smallest systempersons served.

Although current total water costs fortypical small system households rangefrom about $100 to $150 per year, thesecosts are quite low in comparison to thecosts of other utilities. In addition, assystem size increases, the costs of watertreatment per unit volume of waterrapidly decline. For example, using allthe same assumptions, the packed toweraeration costs decrease from 202 centsper thousand gallons for the 25 to 100person (0.013 mgd) system size categoryto 101 cents per thousand gallons for the101 to 500 person (0.037 mgd) systemsize category, and decrease further to 21cents per thousand gallons for the 50,001to 75,000 person (12 mgd) category.Thus, aeration treatment offerssignificant economies of scale, e.g., withrespect to 1,2-dichloroethane removal,as plant size increases by a factor ofthree (0.013 mgd to 0.037 mgd), the costdecreases by a factor of two (202 to101€/1,000 gallons). In addition, costswill be less when lower removalefficiencies are sufficient to achieve thestandard in those cases where the rawwater concentrations are less than 0.5mg/1, which is usually the case.

It should be noted that the costs inTable 3 are based on a variety of data(see Ref. 2). For all the VOCs, exceptvinyl chloride, benzene, and p-dichlorobenzene, carbon usage rates arebased on projection of pilot columndata. Neither adequate adsorptionisotherms nor column data wereavailable to project carbon usage ratesor empty bed contact times for vinyl

- 13,000 gallons/day average flow or 25-100

chloride. As indicated earlier, GACadsorption is not considered BAT for theremoval of vinyl chloride because of thisand other feasibility considerations. Forthe two aromatic compounds, benzeneand p-dichlorobenzene, only carbonadsorption isotherms were available.That is, no pilot column data wereavailable for these two compounds. Tocompensate for this lack of pilot columndata, the cost estimates in Table 3 forthese two compounds were adjusted tobe higher than if column data had beenavailable (see Ref. 2). These costs arebelieved to be adequate for purposes ofdetermining MCLs and estimatingnational economic impacts.

Both pilot- and full-scale datademonstrate that packed tower aerationand granular activated carbon arecapable of 90-99 percent or greaterremovals of the VOCs (except that GACis not as effective as PTA for vinylchloride). In light of this removalefficiency and the potential costimpacts, the Agency considers thetreatment costs to be justified andreasonable; under a worst case scenario,the water rate might double for thesmallest system consumers.Consequently, the Agency hasconcluded that there is no reason tovary the BAT standard for smallsystems.

Required Examination andInstallation of Alternate TreatmentTechnologies. Under section 1415 of theAct, a State may grant variances from a

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NPDWR if certain conditions are met.These conditions, described more fullybelow, include: (1) An inability to meetthe MCLs despite the installation of thebest available technology; (2) a findingthat the variance will not result in anunreasonable risk; (3) imposition of acompliance schedule; (4) implementationof such additional control measures asthe State may require; and, (5) publicnotice of the proposed variance andopportunity for a hearing.

To receive a variance, a PWS wouldbe required to install BAT first even ifthe BAT was not anticipated to achievethe MCL; the objective would be toreduce the level of contaminants asmuch as could be achieved by thosetechnologies. The only exception to thisrequirement is that if a system were todemonstrate that the best availabletechnology only achieved de minimisreduction of the contaminant(s) ofconcern, the system would not have toinstall that technology. However, as acondition of receiving a variancewithout installing BAT, the State couldrequire comprehensive engineeringstudies of other technologies and if anywere technically feasible, it couldrequire one of those technologies to beinstalled.

EPA has identified three additionaltreatment methods that the State mayrequire the PWS to investigate and, iffeasible, to install as a condition ofobtaining a variance. These are: (1)Removal using other aerationtechniques, such as multiple trayaeration, spray aeration, cascadeaeration, diffused aeration, or mechnicalaeration; (2) removal using powderedactivated carbon adsorption; and (3) useof an alternative source of water.

EPA discourages systems from usingan alternative source of water whichhas no VOC contamination but may becontaminated with other substances.Specifically, EPA discourages systemswhich find low levels of VOCs in theirground water source, which is otherwiseof good quality, from switching to asurface water source where the riskfrom disinfection by-products (e.g.,trihalomethanes) might be greater thanfrom the VOCs. In such a case, wherealternative sources pose a greater riskthan the VOC-contaminated supply, thewater supplier should treat the originalwater.

Subsections 1415(a}i1)(A) (i) and (ii) ofthe SDWA require the State to prescribea schedule for compliance at the sametime that it issues a variance, Theschedule must include: (1) Increments ofprogress toward compliance; and (2) animplementation plan of such controlmeasures and application of othertreatment techniques or technologies

that the State considers necessary.These provisions are aimed at bringingthe system into compliance with theMCL as soon as practicable. Thefollowing points need to be taken intoconsideration:

(1) The schedule of compliance whichaccompanies a variance may requirethat the system examine other treatmentmethods (e.g., various aerationtechnologies, powdered activatedcarbon, or alternate sources of water) todetermine their availability, feasibility,,costs, and effectiveness.

(2) Such an examination may includeengineering studies and pilot projects,for potentially applicable technologies,to determine what reduction in VOClevels could be achieved by thetreatment method. EPA will provideguidance on examining technologies forcompliance schedules.

(3) Systems or the State always havethe option of proposing studies of othermethods.

(4) The State can decide whether anyof the possible teatment methods wouldachieve reductions in VOC levelsjustifying use of that particular method.In such cases, the State may require, aspart of the compliance schedule,installation and use of such methods bythe system.

Use of POU Devices and BottledWater. As described above, undersection 1415(a)(1)(A)(ii), the State is toprescribe a schedule for implementationof any additional control measures itmay require. The State may require theuse of POU devices, bottled water, orother mitigating measures as an"additional control measure" during theperiod of a variance, as a condition ofreceiving the variance, if anunreasonable risk to health exists.

In prescribing the use of POU devices,the State would be required to imposethe same conditions as outlined insection III.A.1 for approval of POEdevices. If a PWS distributes bottledwater as a control measure, the PWSmust ensure that the followingconditions are satisfied:

(1)(a) The bottled water is subject to amonitoring program that providesadequate assurances that the watermeets all MCLs. The public watersystem must monitor the bottled waterfor VOCs the first quarter that itsupplies water to the public, andannually thereafter. Results of themonitoring program shall be provided tothe State annually, or

(b) The public water system mustreceive a certification from the bottledwater company that (i) the bottled watersupplied has been taken from an"approved source" as defined in 21 CFR129.3[a); (ii) the bottled water company

has conducted monitoring in accordancewith 21 CFR 129.80(g) (1)-(3); and (iii)the bottled water does not exceed theMCLs or quality limits set out in 21 CFR103.35. The public water system shallprovide the certification to the State thefirst quarter after it supplies bottledwater and annually thereafter; and

(2) The public water system is fullyresponsible for the provision ofsufficient quantities of bottled water toevery person supplied by the publicwater system including delivery via adoor-to-door bottled water deliverysystem.

These conditions constitute theminimum standards for protection ofpublic health.

2. Exemptions

Under section 1416(a), a State mayexempt public water systems from anyrequirements respecting an MCL ortreatment technique requirements of anNPDWR, if it finds that (1) due tocompelling factors (which may includeeconomic factors), the PWS is unable tocomply with the requirement; (2) theexemption will not result in anunreasonable risk to human health; and(3) the PWS was in operation on theeffective date of the NPDWR, or for asystem which was not in operation bythat date, only if no reasonablealternative source of drinking water isavailable to the new system. If a Stategrants an exemption to a public watersystem, it must at the same timeprescribe a schedule for compliance(including increments of progress) andimplementation of appropriate controlmeasures that the State requires thesystem to meet while the exemption is ineffect. Under section 1416(2)(A), theschedule must require compliancewithin one year after the date ofissuance of the exemption. However,section 1416(b)(2)(B) states that theState may extend the final date forcompliance provided in any schedule fora period not to exceed three years, if thepublic water system is taking allpracticable steps to meet the standardand one of the following conditionsapplies: (1) The system cannot meet thestandard without capital improvementswhich cannot be completed within theperiod of the exemption; (2) in the caseof a system which needs financialassistance for the necessaryimplementation, the system has enteredinto an agreement to obtain financialassistance; or (3) the system has enteredinto an enforceable agreement tobecome part of a regional public watersystem. For public water systems whichdo not serve more than 500 serviceconnections and which need financial


assistance for the necessaryimprovements, the State may renew anexemption for one or more additionaltwo-year periods if the systemestablishes that it is taking allpracticable steps to meet therequirements noted above. Section1416(b)(2)C).

Under section 1416(d), EPA is requiredto review State-issued exemptions at:least every three years and, if theAdministrator finds that a State has, ina substantial number of instances,abused its discretion in grantingexemptions or failed to prescribeschedules in accordance with the statuteafter following various procedures, theAdministrator may revoke or modifythose exemptions and schedules. EPAwill use these procedures to strictlyscrutinize exemptions from the MCLs forVOCs granted by states and, ifappropriate, will revoke or modifyexemptions granted.

Under this rule, as a condition ofreceiving an exemption, the State mayrequire the use of POU devices orbottled water for the duration of theexemption. The conditions for the use ofPOU devices or bottled water are thesame as those described for variances insection III.G.1.3. Central Treatment vs. POU/BottledWater

EPA believes that, when treatment isappropriate, central treatment should bethe primary means of attaining MCLs.However, although the long-term goalfor these systems is to meet MCLs withcentrally treated and distributed water,EPA is allowing the State to require theuse of POU devices or bottled water, forinstance, if there is an unreasonble riskto health, as a condition of receiving avariance or an exemption to ensure thatthe PWS provides an interim source ofdrinking water that meets the MCLswhile the system brings its water supplyinto compliance. This is especiallyvaluable in the case of exemptions forsmall systems, i.e., systems with lessthan 500 connections, because theirexemptions may be extended for one ormore two-year periods. The goal isapplication of non-central treatment orbottled water is to provide water ofequivalent quality to that which wouldbe provided by a traditional welloperated central treatment facility.Equivalent means water that meets allPrimary and Secondary Drinking WaterStandards and is not an acceptablequality.H. Public Notification

Under section 1414(c)(1) of the Act,each owner or operator of a publicwater system must give notice to

persons served by it of (1) any violationof any MCL, treatment techniquerequirement, or testing provisionprescribed by an NPDWR; (2) failure tocomply with any monitoring requirementunder section 1445(a) of the Act; (3)existence of a variance or exemption;and (4) failure to comply with therequirements of a schedule prescribedpursuant to a variance or exemption.The 1986 amendments require that,within 15 months of enactment, EPAamend its current public notification.regulations to provide for different typesand frequencies of notice based on thedifferences between violations whichare intermittent or infrequent andviolations which are continuous orfrequent, taking into account theseriousness of any potential adversehealth effects which may be involved.

EPA proposed regulations to revisethe public notification requirements onApril 6, 1987 (52 FR 10972). Theregulations proposed that public noticesfor MCL and treatment techniqueviolations ("Tier I violations") containmandatory health effects languagespecifying concisely and in non-technical terms what adverse healtheffects may occur as a result of theviolation. States and water utilitieswould remain free to add additionalinformation to each notice, as deemedappropriate for specific situations. TheApril 1987 notice proposed specifichealth effects language for the eightVOCs which are subject to today'srulemaking. The April 1987 notice alsoproposed that a CWS with Tier 1violations must notify the public bynewspaper, mail delivery of notice andpress release (for acute violations) isrequired. The proposal states that publicwater systems which fail to comply withany monitoring or testing requirements,which are granted variances orexemptions, or which fail to complywith the requirements of a variance orexemption schedule, would be requiredto give newspaper notice, withadditional notice at State discretion. ThePWS is allowed to post notice undercertain conditions for Tier 1 and Tier 2violations. The Agency expects topromulgate final public notificationregulations in September 1987.

L Reporting Requirements

The current regulations, 40 CFR141.31, require public water systems toreport monitoring data to States withinspecified time periods. EPA did notpropose any changes in theserequirements for the VOCs. Nocomments were received on this issue.Thus, EPA will require the samereporting requirements for the VOCs as

required under the current regulationsfor other contaminants.

The reporting requirements for resultsof the monitoring for unregulatedcontaminants (described below) applyto both the community water systems(CWS) and the NTNCWS. Each CWS orNTNCWS must submit the results of themonitoring within thirty days of receiptfrom the certified laboratory. Theseresults are to be submitted to the State.In addition, the State or public watersystem must submit the followinginformation to EPA for every sample: (1)Results of all the analytical methods,including negatives; (2) name andaddress of the system that supplied thesample; (3) contaminants for which theanalyses were performed; (4) analyticalmethod(s) used; (5) date of sample; and(6) date of analysis.

.Total Volatile Synthetic OrganicChemicals (TVOC)

In the June 12,1984, proposal forMCLGs for the VOCs, EPA requestedpublic comments on setting an MCLGand MCL for total volatile organicchemicals to provide additionalprotection from simultaneous exposureto multiple VOCs. Following analysis ofpublic comments and availablescientific information, EPA determinedthat an MCLG and MCL would not beappropriate at this time. This conclusionwas discussed in the November 1985notice.

K. Monitoring for UnregulatedContaminants

Section 1445(a)(1) of the Act requiresEPA to promulgate regulations byDecember 19, 1987, which require publicwater systems to conduct a monitoringprogram for unregulated contaminants.Each system must monitor at least onceevery five years for unregulatedcontaminants unless EPA requires morefrequent monitoring. This data willassist EPA in determining whetherregulations for these contaminants arenecessary, and if so, what levels mightbe appropriate.

EPA proposed monitoringrequirements for 51 unregulatedcontaminants in the November 1985notice. The Agency also requestedcomment on a method developed for theanalysis of 1,2-dibromoethane (EDB)and 1,2-dibromo-3-chloropropane(DBCP) at low levels. These twocompounds are included among thesubstances that PWSs must monitorunder Section 1445, as discussed below.This method is entitled "Method 504-1,2-Dibromoethane (EDB and 1,2-Dibromo-3-chloropropane in Water byMicroextraction and Gas

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25710 Federal Register / Vol. 52, No. 130 Wednesday, July 8, 1987 / Rules and Regulations

Chromatography." EPA received nocomments on Method 504. The Agencybelieves that this method is adequate todetermine concentrations of EDB andDBCP. Therefore, this method isincluded in this rule as the monitoringmethod for these two contaminants.Several commenters pointed out thatanalysis of 10 to 15 other compounds onthe list of 51 was more difficult thananalysis of the other compounds,resulting in higher costs. In addition,they observed that the likelihood ofthese substances being present is muchless than for other VOCs. EPA agreeswith these comments and thus ispromulgating monitoring regulationswhich separate the unregulatedcontaminants into three lists as follows:

List 1: Monitoring required for allCWS and NTNCWSs. Compounds canbe readily analyzed.

List 2: Monitoring required only forsystems vulnerable to contamination bythese compounds. Compounds havelimited localized occurrence potentialand require some specialized handling.

List 3: The State decides whichsystems would have to analyze for thesecontaminants, which includescompounds that do not elute withinreasonable retention time using packedcolumn methods or are difficult toanalyze because of high volatility orinstability, and are much less likely tobe present in drinking water. ,

EPA is deleting the monitoringrequirements for pentachloroethane andbis(2-chloroisopropyl) ether from the listof unregulated contaminants in the finalrule. Pentachloroethane has beendeleted because it is unstable in water.Bis(2-choroisopropyl) ether has beendeleted because it does not purge well,and there are very few occurrences indrinking water. Therefore, both of theseare low priority compounds forregulation. EPA is addingtetrachloroethylene to List 1 because therulemaking for this contaminant is nowincluded with the contaminantsscheduled for regulation in June 1988and the resulting monitoring data will beuseful (see the November 13, 1985,notice for discussion of thetetrachloroethylene regulation). Inaddition, 1,3-dichloropropene has beenadded to List I because it has beendetected in ground waters and ismeasured by these analytical methods.Data gathered under this Section 1445regulation can be used for compliance.purposes when EPA promulgatesregulations for tetrachloroethylene andany other of these VOCs for which EPAis developing MCLs.

-Table 6presents the three lists ofcompounds.

Table 6-Unregulated Contaminants

List 1: Monitoring Required for AllSystems

BromobenzeneBromodichloromethaneBromoformBromomethaneChlorobenzeneChlorodibromomethaneChloroethaneChloroformChloromethaneo-Chlorotoluenep-ChlorotolueneDibromomethanem-Dichlorobenzeneo-Dicblorobenzenetrans-1,2-Dichloroethylenecis-1,2-DichloroethyleneDichloromethane1,1-Dichloroethane1,1-Dichloropropene1,2-Dichloropropane1,3-Dichloropropane1,3-Dichloropropene2,2-DichloropropaneEthylbenzeneStyrene1,1,2-Trichloroethane1,1,1,2-Tetrachloroethane1,1,2,2-TetrachloroethaneTetrachloroethylene1,2,3-TrichloropropaneToluenep-Xyleneo-Xylenem-Xylene

List 2: Required for Vulnerable Systems

Ethylene dibromide (EDB)1,2-Dibromo-3-Chloropropane (DBCPJ

List 3: Monitoring Required as theState's Discretion

Bromochloromethanen-ButylbenzeneDichlorodifluoromethaneFluorotrichloromethaneHexachlorobutadieneIsopropylbenzenep-IsopropyltolueneNaphthalenen-Propylbenzenesec-Butylbenzenetert-Butylbenzene1,2,3-Trichlorobenzene1,2,4-Trichlorobenzene1,2,4-Trimethylbenzene1,3,5-Trimethylbenzene

The compounds in List 1 can beanalyzed easily with the analyticalmethods in this final rule (Methods502.1, 503.1, and 524.1). As previouslydiscussed, the Agency has alsodeveloped capillary column methods(Methods 502.2 and 524.2) that are alsoavailable for the monitoring of thesecompounds. Monitoring for the

compounds in List 2 (EDB and DBCP)requires much lower limits of detectionand quantitation because of healthconcerns at low levels; as stated above,EPA Method 504 is available for theanalysis of these two compounds atlower levels. Analysis of compounds inLists 2 and 3 is-best accomplished usingthe capillary column methods.

Analysis for unregulatedcontaminants must be conducted inlaboratories approved for VOC analysisby the State. Because the monitoringrequirements for unregulatedcontaminants will go into effect beforefull certification programs can beimplemented, EPA will acceptmonitoring data analysis from thoselaboratories that analyze performanceevaluation samples for VOCs withinacceptable limits of the true value forthe VOCs and that have been approvedfor THM analysis. The acceptance limitsare -L20 percent for concentrations>0.010 mg/I and -40 percent forconcentrations <0.010 mg/1.Laboratories conducting EDB and DBCPanalysis should be approved separatelyby the State.

The monitoring requirements for theunregulated VOCs are similar to thoserequired for the regulated VOCs so thatpublic water systems are encouraged touse the same samples for all theanalyses and to have the analysis of theunregulated VOCs performed with theanalysis for the regulated VOCs, therebyreducing the costs of both sampling andanalysis. This approach was generallysupported by commenters.

The State would determine whether torequire consecutive systems to monitorfor VOCs and trihalomethanes underSection 1445 for systems with apopulation of less than 10,000. If theconsecutive system disinfects, then thesamples for trihalomethanes should betaken after disinfection, This is becausethese systems currently do not monitorfor trihalomethanes and trihalomethaneconcentrations usually increase afterdisinfection by the consecutive systems.

The November 1985 proposal did notinclude repeat monitoring forunregulated VOCs (unless imposed by,the State). In this final rule, however,EPA is requiring repeat monitoring forunregulated: contaminants every fiveyears, as specified in the SDWAAmendments.of 1986. However, EPAexpects to specify a new list forunregulated contaminant monitoringwithin five years. This means that PWSswill not actually have to conduct repeatmonitoring for the list of 50 specified inthis notice, but instead will monitor for anew list In five years; However, Statesare encouraged to require follow-up "


monitoring for these 50 contaminantsand mitigation procedures as needed ifcontamination is indicated.

States may delete contaminants fromthe list if EPA approves, and can addcontaminants to the list for individualpublic water systems without EPAapproval. The State may apply to EPAfor approval in order to delete asubstance for an individual watersystem by certifying to EPA that it hasused the vulnerability criteria inreaching that decision. EPA will retainoversight authority of this process.

Section 1445(a)(6) states that EPA maywaive the monitoring requirements forunregulated VOCs for systems that haveconducted monitoring programs sinceJanuary 1, 1983. EPA will waive thisrequirement only if the monitoringprogram was consistent with therequirements promulgated today."Consistent" means 'the samplinglocations, sampling techniques, andanalytical methods are the same, andthe analyses were performed byqualified laboratories (i.e., laboratoriesthat are THM-certified) with adequatequality control. While EPA would preferthat all of the 33 VOCs on List I wouldhave been included in the previousmonitoring program, the Agency intendsthe requirements to be flexible so thatsystems that have monitored for most ofthe 33 VOCs could qualify for a waiver.For example, if 30 of 33 VOCs wereincluded in a previous monitoringprogram by a particular system, thatsystem might qualify for a waiverdepending upon which three VOCs werenot included. If these were relativelyhigh occurrence VOCs, then a waiverwould be inappropriate. Other factorsthat EPA will consider are the results ofthe monitoring program for thecontaminants that were analyzed andthe system's vulnerability status.

Under section 1445(a)(7), systemsserving fewer than 150 connections aretreated as complying with theunregulated contaminant monitoringrequirements if the systems providewater samples or the opportunity forsampling. While EPA encourages thesesystems to request the additionalanalytical results for the unregulatedcontaminants from laboratoriesconducting their analysis for VOCcompliance monitoring since theadditional cost is relatively small(probably $50 or less), this is not arequirement of this rule. Under the finalrule, these systems are required to senda letter to the State specifying that theirsystem is available for sampling; nosamples are to be sent unless requestedby the State.

States or the water systems maycomposite up to 5 samples when

monitoring for unregulatedcontaminants. The compositingprocedure is described in the section onCompliance Monitoring.

IV. Effective Dates

These regulations have an effectivedate of January 1, 1988: the laboratoryperformance requirements andmonitoring for compliance requirements(§ 141.24(g)) and the unregulatedmonitoring and reporting requirements(§ 141.35 and 141.40) [Prior to theadoption of the compliance monitoringrequirements by the State, the authorityfor compliance monitoring is section1445 of the Act). All other provisionspromulgated in this final rulemaking(concerning MCLs, variance, andexemptions, provisions of reporting andrecordkeeping) are effective January 9,1989, as provided in section 1412(b)(10).

V. Impact Analyses

The economic impact analysissupporting this final rule is contained in"Economic Impact Analysis of ProposedRegulations to Control VolatileSynthetic Organic Chemicals in DrinkingWater," October 1985, as amended (Ref.3). The report presents estimates of thebenefits and costs of regulatoryalternatives. Also included are analysesrequired by the Regulatory FlexibilityAct and the Paperwork Reduction Act.The purpose of the assessment was todetermine overall economic impacts ofthe regulations. The addendum to theassessment responds to comments madeduring the public comment period. Therehas been no significant change in theinitial assessment, which showed thatapproximately 1300 community watersupplies would be expected to exceedthe final standards without additionalcontrols. If nearly all these systems tookactions to comply with the regulations,the total present value cost ofcompliance to the nation would beabout $280 million. On an annualizedbasis, the cost of compliance would be$21 million per year. Extending the VOCregulations to non-community non-transient water systems will requireapproximately 400 additional systems totreat their water, at a capital cost of $20million and approximately $1.5 millionper year.

The cost impacts on community watersystems and consumers affected byvolatile organic contamination vary,depending upon the size of the PWS.Very small systems which serve from 25to 500 people could be expected toincrease their water rates byapproximately 54 cents per 1000 gallonsof water. As a result of economies ofscale, large community systems servingmore than 50,000 people could be

expected to increase their rates onlyabout 5 cents per 1000 gallons. Theseincreases would only affect systemswith contaminant levels above thestandards.

Under Executive Order 12291, EPAmust judge whether a regulation is"major" and, therefore, subject to therequirements of a Regulatory ImpactAnalysis. This action does not constitutea " major" regulatory action because itwill not have a major financial oradverse impact on the country. Thisregulation has been reviewed by theOffice of Management and Budget asrequired by Executive Order 12291 andtheir comments are available in thepublic docket.

The costs of compliance monitoringand monitoring for the unregulatedcontaminants are presented in Table 7(see Ref. 3). As noted above, compositesof up to five sources are allowed and thecosts shown in Table 7 assume thatsystems composite a number of theirsources, In addition, certain Statesconduct monitoring for small systems.Compositing of different system sourcesby States is allowed in the regulations;savings are estimated to be $500,000 peryear for the initial compliancemonitoring, $200,000 per year for theinitial unregulated monitoring, and$400,000 per year for the repeatcompliance monitoring.

TABLE 7.-COSTS ($ MILLION/YEAR)FOR MONITORING FOR COMPLIANCEWITH MCLS FOR VOCS AND FORUNREGULATED VOCS

Initial Round:VOCs subject to MCLs ....... * ........Unregulated contaminants ................

Repeat Monitoring:VOCs subject to MCLs ......................Unregulated contaminants ................

$7.5$1.7

$19.21

I The cost for repeat monitoring of unregu-lated contaminants will vary because theAgency will specify a new list of contaminantsto be monitored in five years. Consequently,contaminants other than those specified inthis notice may be listed at that time.

The Regulatory Flexibility Actrequires EPA to explicitly consider theeffect of regulations on small entities. Ifthere is a significant effect on'asubstantial number of small systems, theAgency must seek means to minimizethe effects. With respect to therequirements of the RegulatoryFlexiblity Act, 5 U.S.C. 602 et seq.,today's action will not have a significanteffect on a substantial number of smallentities. Using the Small Business .

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25712 Federal Register / Vol. 52, No. 130 / Wednesday, July 8, 1987 / Rules and Regulations.

Administration's definitions, a "small".water utility is one that serves'fewer ,than 50,000 people. There are about78,500 such systems. Of these, fewer.than 1700 are likely to have.contamination levels greater than .th .MCLs.' Therefore, this rule will affectabout that 2 percent of the "small" ,systems, which does not constitute asubstantial number of small systems.However, it is possible that today's •action Will have a substantial impact ona few small systems if regulated VOCs'are found at levels higher than the MCL.Therefore, the Agency has attempted to.provide alternatives to the requirementswhenever possible. Specifically, EPAallows compositing of samples. Smallsystems may choose to composite theirsamples and to share the analyticalcosts. Also, the Agency has allowed.bottled water and point-of-use devicesas conditions of receiving a variance orexemption, even though decentralizedtreatment is less than the Agency's long-range goal of centralized treatment (dueto untreated taps-and possible . , •inhalation effects), to accommodate theneeds of the smaller systems withlimited resources. The Agency also hasgiven states the discretion to reducemonitoring frequency in accordancewith a system's findings of no VOCs andits vulnerability status. Consequently,small systems which do not have VOCcontamination in their water supply andare not located in a vulnerable area mayhave to monitor only infrequently. Inaddition, very small systems are notrequired to sample for unregulatedcontaminants; they are only required toprovide a sample or make theopportunity for sampling available tothe State.

The information collectionrequirements in this rule have beensubmitted for approval to the Office ofManagement and Budget (OMB) underthe paperwork Reducation Act, 44 U.S.C.3501 et seq. The information collectionrequirements are not effective untilOMB approves them and a technicalamendment to that effect is published inthe Federal Register.

VI. References and Public DocketThe following references are referred

to in this notice and are included in thePublic Docket together with othercorrespondence and information. ThePublic Docket is available for viewingby appointment in Washington,, D.C. bycalling the telephone number at thebeginning of this notice. All publiccomments received on the proposal areincluded in the Docket.

(1) * U.S. Environmental ProtectionAgency, Criteria'and StandardsDivision, Analytical Methods/

Monitoring'the VOCs in Drinking Water.June, 1987..(. 2) * U.S. Environmental ProtectionAgency; Criteria and StandardsDivision, Techologies and Costs for theRemoval of Volatile Organic Chemicalsfrom Potable Water Supplies. May, 1985.

(3)* U.S. Environmental ProtectionAgency, Office of Program Developmentand Evaluation, Economic ImpactAnalysis of Proposed Regulations to: Control Volatile Synthetic OrganicChemicals in Drinking Water. October,1985, as amended 1987..

-- (4) U.S. Environmental Protection'Agency, Criteria and StandardsDivision, Summary of Comments andEPA Responses on the Proposed MCLsfor the VOCs, Reproposed MCLG forpara-Dichlorobenzene, and"Requirements for UnregulatedContaminants." (June 1987)

(5) Peters, W., and Clark, S. Memo:Risks Associated With Air Emissionsfrom Aeration of Drinking Water. ToRobert G. Kellam, Program Analysis andTechnology Section and Arthur H.Perler, Science and Technology Branch,Criteria and Standards Division, Officeof Drinking Water. Nov. 13, 1985.

(6)* National Toxicology Program,Toxicology and Carcinogenesis Studiesof 1,4-Dichlorobenzene in F344 Rats andB6C3Fi Mice (Gavage Studies), finalreport, 1987 (Technical Report Series No.319).

(7) U.S. Environmental ProtectionAgency Ground Water Supply SurveyJanuary 1983.

(8) U.S. Environmental ProtectionAgency, Criteria and StandardsDivision. Criteria Document for ortho-Dichlorobenzene, meta-Dichlorobenzene, and parap-Dichlorobenzene. (June 1987)

The starred (*) documents are available fora fee from the National Technical InformationService, U.S. Department of Commerce, 5285Port Royal Road, Springfield, VA 22161. Thetoll-free number is 703/487-4650. Thesedocuments are also available for review atthe Drinking Water Supply Branch Office in.EPA's Regional Offices.

List of Subjects in 40 CFR Parts 141 and142

Chemicals, Reporting and record-keeping requirements, Water supply,Administrative practice and procedure.

Dated: June 19,1987.Lee M. Thomas,Administrator, Environmental ProtectionAgency.

Therefore, 40 CFR Parts 141 and 142are amended as follows:

-PART 141-[AMENDED]

1. In Part 141:

a. The authority citation for Part 141continues to read as follows:

Authority: 42 U.S.C. 300g-1, 300g-3, 300j-4,300g-6, and 300j-9. -

b. In § 141.2, the existing paragraphdesignations are removed, the existingparagraphs are arranged in alphabeticalorder, and the following new definitionsare added:

§ 141.2. Definitions.

"Best available technology" or .'BAT"means the best technology, treatmenttechniques, or other means which theAdministrator finds, after examinationfor efficacy under field conditions andnot solely under laboratory conditions,are available (taking cost intoconsideration). For the purposes ofsetting MCLs for synthetic organicchemicals, any BAT must be at least aseffective as granular activated carbon.

"Non-transient non-community watersystem or "NTNCWS" means a public.water system that is not a communitywater system and that regularly servesat least 25 of the same persons. over 6months per year.

"Point-of-entry treatment device" is atreatment device applied to the drinkingwater entering a house or building forthe purpose of reducing contaminants inthe drinking water distributedthroughout the house or building.

"Point-of-use treatment device" is atreatment device applied to a single tapused for the purpose of reducingcontaminants in drinking wafer at thatone tap.

c. A new paragraph (g) is added to§ 141.24 to read as follows:

§ 141.24 Organic chemicals other thantotal trihalomethanes, sampling andanalytical requirements.

(g) Analysis of the contaminants listedin § 141.61(a) for purposes ofdetermining compliance with themaximum contaminant levels shall beconducted as follows:

(1) Ground-water systems shallsample at points of entry to thedistribution system representative ofeach well. Sampling must be conductedat the same location or a morerepresentative location each quarter..Ground-water systems must sampleevery three months for each entry pointto the distribution system except asprovided in paragraph (g)(8)(i) of thissection.

Federal Register / Vol.,52, No." 130/ Wednesday, July 8, 19870 / tiles and Regulati.ons

(2) Surface water systems shallsample at points in the distributionsystem representative of each source orat entry points to the distribution systemafter any application of treatment.Surface water systems must sampleeach source every three months exceptas provided in paragraph (g)(8)(ii) of thissection. Sampling must be conducted atthe same location or a morerepresentative location each quarter.

(3) If the system draws water frommore than one source and sources arecombined before distribution, thesystem must sample at an entry point tothe distribution system during periods ofnormal operating conditions.

(4) All community water systems andnon-transient, non-community watersystems serving more than 10,000 peopleshall analyze all distribution or entry-point samples, as appropriate,representing all source waters beginningno later than January 1, 1988. Allcommunity water systems and non-transient non-community water systemsserving from 3,300 to 10,000 people shallanalyze all distribution or entry-pointsamples, as required in this paragraph(g), representing source waters no laterthan January 1, 1989. All othercommunity and non-transient, non-community water systems shall analyzedistribution or entry-point samples, asrequired in this paragraph (g),representing all source waters beginningno later than January 1, 1991.

(5) The State or EPA may requireconfirmation samples for positive ornegative results. If a confirmationsample(s) is required by EPA or theState, then the sample result(s) shouldbe averaged with the first samplingresult and used for compliancedetermination in accordance with (g)(9)of this section. States have discretion todelete results of obvious sampling errorsfrom this calculation.

(6) Analysis for vinyl chloride isrequired only for ground water systemsthat have detected one or more of thefollowing two-carbon organiccompounds: Trichloroethylene,tetrachloroethylene, 1,2-dichloroethane,1,1,1-trichloroethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1-dichloroethylene. The analysis for vinylchloride is required at each distributionor entry point at which one or more ofthe two-carbon organic compounds werefound. If the first analysis does notdetect vinyl chloride, the State mayreduce the frequency of vinyl chloridemonitoring to once every three years forthat sample location or other samplelocations which are more representativeof the same source. Surface watersystems may be required to analyze for

vinyl chloride at the discretion of theState.

(7) A State or individual public watersystems may choose to composite up tofive samples from one or more publicwater systems. Compositing of samplesis to be done in the laboratory by theprocedures listed below. Samples shouldbe analyzed within fourteen days ofcollection. If any organic contaminantlisted in § 141.61(a) VOC is detected inthe original composite sample, a samplefrom each source that made up thecomposite sample must be reanalyzedindividually within fourteen days fromsampling. The sample for reanalysiscannot be the original sample but can bea duplicate sample. If duplicates of theoriginal samples are not available, newsamples must be taken from each sourceused in the original composite andanalyzed for VOCs. Reanalysis must beaccomplished within fourteen days ofthe second sample. To compositesamples, the following procedure mustbe followed:

(i) Compositing samples prior to GCanalysis.

(A) Add 5 ml or equal larger amountsof each sample (up to 5 samples areallowed] to a 25 ml glass syringe.Special precautions must be made tomaintain zero headspace in the syringe.

(B) The samples must be cooled at 4°

C during this step to minimizevolatilization losses.

(C) Mix well and draw out a 5-mIaliquot for analysis.

(D) Follow sample introduction,purging, and desorption steps describedin the method.

(E) If less than five samples are usedfor compositing, a proportionatelysmaller syringe may be used.

(ii) Compositing samples prior to GC/MS analysis.

(A) Inject 5-ml or equal largeramounts of each aqueous sample (up to5 samples are allowed) into a 25-mlpurging device using the sampleintroduction technique described in themethod.

(B) The total volume of the sample inthe purging device must be 25 ml.

(C) Purge and desorb as described inthe method.

(8) The State may reduce themonitoring frequency specified inparagraphs (g) (1) and (2) of this section,as explained in this paragraph asfollows:

(i) The monitoring frequency forground-water systems is as follows:

(A) When VOCs are not detected inthe first sample (or any subsequentsamples that may be taken) and thesystem is not vulnerable as defined inparagraph (g)(8)(iv) of this section,

monitoring must be repeated every 5years.

(B) When VOCs are not detected inthe first sample (or any subsequentsample that may be taken) and thesystem is vulnerable as defined inparagraph (g)(8)[iv) of this section,

(1) Monitoring must be repeated every3 years for systems >500 connections.

(2) Monitoring must be repeated every5 years for system <500 connections.

(C) If VOCs are detected in the firstsample (or any subsequent sample thatmay be taken), regardless ofvulnerability, monitoring must berepeated every 3 months, as requiredunder paragraph (g)(1) of this section.

(ii) The repeat monitoring frequencyfor surface water systems is as follows:

(A) When VOCs are not detected inthe first year of quarterly sampling (orany other subsequent sample that maybe taken) and the system is notvulnerable as defined in paragraphg(8)(iv), monitoring is only required atstate discretion.

(B) When VOCs are not detected inthe first year of quarterly sampling (orany other subsequent sample that maybe taken) and the system is vulnerableas defined in paragraph (g)(8)(iv) of thissection,

(1) Monitoring must be repeated inthree years (for systems >500connections.)

(2) Monitoring must be repeated everyfive years (for systems <500connections.)

(C) When VOCs are detected in thefirst year of quarterly sampling (or anyother subsequent sample that may betaken), regardless of vulnerability,monitoring must be repeated every 3months, as required under paragraph(g)(2) of this section.

(iii) States may reduce the frequencyof monitoring to once per year for aground-water system or surface watersystem detecting VOCs at levelsconsistently less than the MCL for threeconsecutive years.

(iv) Vulnerability of each public watersystem shall be determined by the Statebased upon an assessment of thefollowing factors:

(A) Previous monitoring results.(B) Number of persons served by

public water system.(C) Proximity of a smaller system to a

larger system.(D) Proximity to commercial or

industrial use, disposal, or storage ofVolatile Synthetic Organic Chemicals.

(E) Protection of the water source.(v) A system is deemed to be

vulnerable for a period of three yearsafter any positive measurement of oneor more contaminants listed in either

25713my m ----


§ 141.61(a) or § 141.40(e) except fortrihalomethanes or other demonstrateddisinfection by-products.

(9) Compliance with § 141.61(a) shallbe determined based on the results ofrunning annual average of quarterlysampling for each sampling location. Ifone location's average is greater thanthe MCL, then the system shall bedeemed to be out of compliance. If apublic water system has a distributionsystem separable from other parts of thedistribution system with nointerconnections, only that part of thesystem that exceeds any MCL asspecified in Section 141.61(a) will bedeemed out of compliance. States mayreduce the public notice requirement tothat portion of the system which is outof compliance. If any one sample resultwould cause the annual average to beexceeded, then the system shall bedeemed to be out of complianceimmediately. For systems that only takeone sample per location because noVOCs were detected, compliance shallbe based on that one sample.

(10) Analysis under this paragraphshall be conducted using the followingEPA methods or their equivalent asapproved by EPA. These methods arecontained in "Methods for theDetermination of Organic Compounds inFinished Drinking Water and RawSource Water," September 1986,available from Environmental andSupport Laboratory (EMSL), EPA,Cincinnati, OH 45268 or the State.

(i) Method 502.1, "VolatileHalogenated Organic Chemicals inWater by Purge and Trap GasChromatography."

(ii) Method 503.1, "Volatile Aromaticand Unsaturated Organic Compounds inWater by Purge and Trap GasChromatography."

(iii) Method 524.1, "Volatile OrganicCompounds in Water by Purge and TrapGas Chromatography/MassSpectrometry."

(iv) Method 524.2, "Volatile OrganicCompounds in Water by Purge and TrapCapillary Column Gas Chromatography/Mass Spectrometry."

(v) Method 502.2, "Volatile OrganicCompounds in Water by Purge and TrapCapillary Gas Chromatography withPhotoionization and ElectrolyticConductivity Detectors in Series."

(11) Analysis under this section shallonly be conducted by laboratories thathave received conditional approval byEPA or the State according to thefollowing conditions:

(i) To receive conditional approval toconduct analyses for benzene, vinylchloride, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane,

and paradichlorobenzene the laboratorymust:

(A) analyze Performance Evaluationsamples which include these substancesprovided by EPA EnvironmentalMonitoring and Support Laboratory orequivalent samples provided by theState.

(B) achieve the quantitativeacceptance limits under paragraphs(g)(11)(i)(C) and {g)(11J(llD) of thissection for at least six of the sevensubject organic chemicals. States mayallow fewer than six of the seven.

(C) achieve quantitative results on theanalyses performed under (g)[11)(i)(A)that are within ±20 percent of theactual amount of the substances in thePerformance Evaluation sample whenthe actual amount is greater than orequal to 0.010 mg/l.

(DJ achieve quantitative results on theanalyses performed under (g)((11)(i)(A)of this section that are within ±40percent of the actual amount of thesubstances in the PerformanceEvaluation sample when the activeamount is less than 0.010 mg/l.

(E) achieve a method detection limitof 0.0005 mg/l, according to theprocedures in Appendix B of Part 136.'

(F) be currently approved by EPA orthe State for the analyses oftrihalomethanes under § 141.30.

(ii) To receive conditional approvalfor vinyl chloride, the laboratory must:

(A) Analyze Performance Evaluationsamples provided by EPA EnvionmentalMonitoring and Support Laboratory orequivalent samples provided by theState.

(B) Achieve quantitative results on theanalyses performed under (g)(11)(ii)(A)of this section that are within _40percent of the actual amount of vinylchloride in the Performance Evaluationsample.

(C) Achieve a method detection limitof 0.0005 mg/l, according to theprocedures in Appendix B of Part 136.

(D) Receive approval or be currentlyapproved by EPA or the State under(g)(11)(i) of this section.

(12) States have the authority to allowthe use of monitoring data collectedafter January 1, 1983, for purposes ofmonitoring compliance. If the data isconsistent with the other requirementsin this paragraph, States may use thatdata to represent the initial monitoring ifthe system is determined by the Statenot to be vulnerable under therequirements of this section. In addition,the results of EPA's Ground WaterSupply Survey can be used in a similarmanner for systems supplied by a singlewell.

(13) States may increase requiredmonitoring where necessary to detectvariations within the system.

(14) The State has the authority todetermine compliance or initiateenforcement action based uponanalytical results and other informationcompiled by their sanctionedrepresentatives and agencies.

(15) A public water system supplyingfewer than 150 service connections shallbe treated as complying with themonitoring requirements if the owner oroperator sends a letter to the Statespecifying that their system is availablefor sampling. No samples may be sent tothe State unless so requested. This lettermust be sent to the State no later thanJanuary 1. 1991.

(16) States may exempt a public watersystem that obtains treated water fromanother public water system servingmore than 10,000 persons fromconducting compliance monitoring forthe organic chemicals under § 141.61(a),provided that the system from which thewater is obtained has conducted theanalyses required under § 141.61(a).

(17) Public water systems exemptedby the State under (g)(16) and whichdisinfect are required to monitor under§ 141.40.

(18) Each approved laboratory mustdetermine the method detection limit(MDL), as defined in Appendix B to Part136, at which it is capable of detectingVOCs. The acceptable MDL is 0.0005mg/l. This concentration is the detectionlevel for purposes of paragraphs (g) (5),(6), (7), and (8) of this section.

d. Section 141.32 is amended byrevising the first phrase of paragraph (a)to read as follows:

§ 141.32 Public notification.

(a) If a community water system ornon-transient non-community watersystems fails to comply with anapplicable maximum contaminant levelestablished in Subpart B or G, * *

e. A new § 141.35 is added to SubpartD to read as follows:§ 141.35 Reporting and public notificationfor certain unregulated contaminants.

(a) The requirements of this sectiononly apply to the contaminants listed in§ 141.40.

(b) The owner or operator of acommunity water system or non-transient, non-community water systemwho is required to monitor under§ 141.40 shall send a copy of the resultsof such monitoring within 30 days ofreceipt and any public notice underparagraph (d) of this section to the State.

Federal Register / Vol'. 52, No. 130 / Wednesday, July 8, 1987 / Rules and Regulations

(c) The State, or the community watersystem or non-transient, non-communitywater system if the State has notadopted regulations equivalent to§ 141.40, shall furnish the followinginformation to the Administrator foreach sample analyzed under § 141.40:

(1) Results of all analytical methods,including negatives;

(2) Name and address of the systemthat supplied the sample;

(3) Contaminant(s);(4) Analytical method(s) used;(5) Date of sample;(8) Date of analysis.(d) The owner or operator shall notify

persons served by the system of theavailability of the results of samplingconducted under § 141.40 by including anotice in the first set of water billsissued by the system after the receipt ofthe results or written notice within threemonths. The notice shall identify aperson and supply the telephone numberto contact for information on themonitoring results.

f. Section 141.40 is revised to read asfollows:

§ 141.40 Special monitoring for organicchemicals.

(a) All community and non-transient,non-community water systems shallmonitor for the contaminants listed inparagraph (e) in this section by datespecified in Table 1:TABLE 1.-MONITORING COMPLETION DATE BY

SYSTEM SIZE

Monitoring toNumber of persons served begin no later

than-

Over 10,000 ...................................................... Jan. 1, 19883,300 to 10,000 ................................................ Jan. 1, 1989.Less than 3,300 ............................................... Jan. 1, 1991.

(b) Surface water systems shallsample in the distribution systemrepresentative of each water source orat entry points to the distributionsystem. The minimum number ofsamples is one year of quarterly samplesper water source.

(c) Ground water systems shallsample at points of entry to thedistribution system representative ofeach well. The minimum number ofsamples is one sample per entry point tothe distribution system.

(d) The State may requireconfirmation samples for positive ornegative results.

(e) Community water systems andnon-transient, non-community watersystems shall monitor for the followingcontaminants except as provided inparagraph (f) of this section:

(1) Chloroform(2) Bromodichloromethane

(3) Chlorodibromomethane(4) Bromoform(5) trans-1,2-Dichloroethylene(6) Chlorobenzene(7) m-Dichlorobenzene(8) Dichloromethane(9) cis-1,2-Dichloroethylene(10) o-Dichlorobenzene(11) Dibromomethane(12) 1,1-Dichloropropene(13) Tetrachloroethylene(14) Toluene(15) p-Xylene(16) o-Xylene(17) m-Xylene(18) 1,1-Dichloroethane(19) 1,2-Dichloropropane(20) 1,1,2,2-Tetrachloroethane(21) Ethylbenzene(22) 1,3-Dichloropropane(23) Styrene(24) Chloromethane(25) Bromomethane(26) 1,2,3-Trichloropropane(27) 1,1,1,2-Tetrachloroethane(28) Chloroethane(29) 1,1,2-Trichloroethane(30) 2,2-Dichloropropane(31) o-Chlorotoluene(32) p-Chlorotoluene(33) Bromobenzene(34) 1,3-Dichloropropene(35) Ethylene dibromide (EDB)(36) 1,2-Dibromo-3-chloropropane

(DBCP)(f) Community water systems and

non-transient non-community watersystems must monitor for EDB andDBCP only if the State determines theyare vulnerable to contamination byeither or both of these substances. Forthe purpose of this paragraph, avulnerable system is defined as asystem which is potentiallycontaminated by EDB and DBCP,including surface water systems wherethese two compounds are applied,manufactured, stored, disposed of, orshipped upstream, and for ground-watersystems in areas where the compoundsare applied, manufactured, stored,disposed of, or shipped in the ground-water recharge basin, or for ground-water systems that are in proximity tounderground storage tanks that containleaded gasoline.

(g) Analysis under this section shallbe conducted using the recommendedEPA methods as follows, or theirequivalent as determined by EPA: 502.1,"Volatile Halogenated OrganicCompounds in Water by Purge and TrapGas Chromatography," 503.1, "VolatileAromatic and Unsaturated OrganicCompounds in Water by Purge and TrapGas Chromatography," 524.1, "VolatileOrganic Compounds in Water by Purgeand Trap Gas Chromatography/MassSpectrometry," 524.2, "Volatile Organic

Compounds in Water by Purge and TrapCapillary Column Gas Chromatography/Mass Spectrometry, or 502.2, "VolatileOrganic Compounds in Water by Purgeand Trap Gas Chromatography withPhotoionization and ElectrolyticConductivity Detectors in Series." Thesemethods are contained in "Methods forthe Determination of OrganicCompounds in Finished Drinking Waterand Raw Source Water," September1986, available from EnvironmentalMonitoring and Support Laboratory(EMSL), EPA, Cincinnati, Ohio 45268.Analysis of 1,2-dibromo-3-chioropropane (DBCP) and 1,2-dibromoethane (EDB) shall beconducted by Method 504,"Measurement of 1,2,-Dibromoethane(EDB) and 1,2-Dibromo-3-chloropropane(DBCP) in Drinking Water byMicroextraction and GasChromatography," September 1986,available from EMSL, Cincinnati, Ohio45268 or the State.

(h) Analysis under this section shallonly be conducted by laboratoriesapproved under § 141.24(g)(11). Inaddition to the requirements of§ 141.24(g)(11), each laboratoryanalyzing for EDB and DBCP mustachieve a method detection limit forEDB and DBCP of 0.00002 mg/l,according to the procedures in AppendixB of Part 136.

(i) Public water systems may usemonitoring data collected any time afterJanuary 1, 1983 to meet the requirementsfor unregulated monitoring, providedthat the monitoring program wasconsistent with the requirements of thissection.

(j) Monitoring for the followingcompounds is required at the discretionof the State:

(1) 1,2,4-Trimethylbenzene(2) 1,2,4-Trichlorobenzene(3) 1,2,3-Trichlorobenzene(4) n-Propylbenzene(5) n-Butylbenzene(6) Naphthalene(7) Hexachlorobutadiene(8) 1,3,5-Trimethylbenzene(9) p-Isopropyltoluene(10) Isopropylbenzene(11) Tert-butylbenzene(12) Sec-butylbenzene(13) Fluorotrichloromethane(14) Dichlorodifluoromethane(15) Bromochloromethane(k) Instead of performing the

monitoring required by this section, acommunity water system or non-transient, non-community water systemserving fewer than 150 serviceconnections may send a letter statingthat its system is available for sampling.

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25710 Federal Register / Vol. 52. No. 130 / Wednesday, July 8, 1987 / Rules and Regulations

(1) All community and non-transient,non-community water systems shallrepeat the monitoring required in§ 141.40 no less frequently than everyfive years from the dates specified in§ 141.40fa).

g. Section 141.50 is amended byrevising paragraph (b) to read asfollows:

§ 141.50 Maximum contaminant level goalsfor organic contaminants.

(b) MCLGs for the followingcontaminants are as indicated:

Contaminant MCLG

(1) 1.1-Dichloroethylene ................................... ..... 0.007(2) 1,1,1-Trichloroethane .......................................... 0.20(3) para-Dichlorobenzene . ... . ....... . 0.075

h. Section 141.60 is revised to read as

follows:

§ 141.60 Effective dates.(a) The effective date for § 141.61 is

January 9, 1989.(b) The effective date for

§ 141.62(b)(2) is October 2, 1987.i. Section 141.61 is added as follows:

§ 141.61 Maximum contaminant levels fororganic contaminants.

(a) The following maximumcontaminant levels for organiccontaminants apply to community watersystems and non-transient non-community water systems.

MaximumCAS No. Contaminant contaminant

level in mg/I

71-43-2 Benzene ............................................ 0.00575-01-4 Vinyl chlotide ............................... 0.00256-23-5 Carbon tetrachloride ................. 0.005

107-06-2 1,2-Dichloroethane.. 0.00579-01-6 Trichloroethylene... 0.00575-35-4 1,1 -Dichloroethylene ....................... 0.00771-55-6 1:1,1 -Trichloroetane ...................... 0.20

106-46-7 para-Dichlorobenzene .................... 0.075

(b) The Administrator, pursuant tosection 1412 of the Act, hereby identifiesthe following as the best technology,treatment techniques, or other meansgenerally available for achievingcompliance with the maximumcontaminant level for synthetic organicchemicals (§ 141.61(a)): Centraltreatment using packed tower aeration:central treatment using granularactivated carbon for all these chemicalsexcept vinyl chloride.

j. Part 141 is amended by adding anew Subpart 1, consisting of §141.100and § 141.101, to read as follows.Subparts H and I are reserved.

Subpart J--Use of Non-CentralizedTreatment Devices

Sec.141.100 Criteria and procedures for public

water systems using point-of-entrydevices.

141.101 Use of other non-centralizedtreatment devices.

Subpart J-Use of Non-CentralizedTreatment Devices

§ 141.100 Criteria and procedures forpublic water systems using point-of-entrydevices.

(a] Public water systems may usepoint-of-entry devices to comply withmaximum contaminant levels only ifthey meet the requirements of thissection.

(b) It is the responsibility of the publicwater system to operate and maintainthe point-of-entry treatment system.

(c) The public water system mustdevelop and obtain State approval for amonitoring plan before point-of-entrydevices are installed for compliance.Under the plan approved by the State,point-of-entry devices must providehealth protection equivalent to centralwater treatment. "Equivalent" meansthat the water would meet all Primaryand Secondary Drinking WaterStandards and would be of acceptablequality similar to water distributed by awell-operated central treatment plant. Inaddition to the VOCs. monitoring mustinclude physical measurements andobservations such as total flow treatedand mechanical condition of thetreatment equipment.

(d) Effective technology must beproperly applied under a plan approvedby the State and the microbiologicalsafety of the water must be maintained.

(1) The State must require adequatecertification of performance, fieldtesting, and, if not included in thecertification process, a rigorousengineering design review of the point-of-entry devices.

(2) The design and application of thepoint-of-entry devices must consider thetendency for increase in heterotrophicbacteria concentrations in water treatedwith activated carbon. It may benecessary to use frequent backwashing,post-contractor disinfection, andHeterotrophic Plate Count monitoring toensure that the microbiological safety ofthe water is not compromised.

(e] All consumers shall be protected.Every building connected to the systemmust have a point-of-entry deviceinstalled, maintained, and adequatelymonitored. The State must be assuredthat every building is subject totreatment and monitoring, and that therights and responsibilities of the public

water system customer convey with titleupon sale of property.

§ 141.101 Use of other non-centralizedtreatment devices.

Public water systems shall not usebottled water or point-of-use devices toachieve compliance with an MCL.Bottled water or point-of-use devicesmay be used on a temporary basis toavoid an unreasonable risk to health.

PART 142-[AMENDED]

2. In Part 142:

a. The authority citation for 40 CFRPart 142 continues to read as follows:

Authority: 42 U.S.C. 300g-2. 300g-3, 300g-4,300g-5, 300j-4, and 300j-9.

b. A new § 142.56 is added to SubpartF. to read as follows:

§ 142.56 Bottled water and point-of-usedevices.

(a) A State may require a public watersystem to use bottled water or point-of-use devices as a condition for grantingan exemption from the requirements of§ 141.61(a) of this part.

(b) Public water systems that usebottled water as a condition of obtainingan exemption from the requirements of§ 141.61(a) must meet the requirementsset out in § 142,62(f) of this part.

(c) Public water systems that usepoint-of-use devices as a condition forreceiving an exemption must meet therequirements set out in § 142.62(g) ofthis part.

c. Anew § 142.62 is added to SubpartG to read as follows:

§ 142.62 Variances from the maximumcontaminant levels for synthetic organicchemicals.

(a) The Administrator, pursuant tosection 1415(a)(1}(A) of the Act, herebyidentifies the following as the besttechnology, treatment techniques, orother means available for achievingcompliance with the maximumcontaminant levels for synthetic organicchemicals: Removal using packed toweraeration; removal using granularactivated carbon (except for vinylchloride.

(b) A State shall require communitywater systems and non-transient, non-community water systems to installand/or use any treatment methodidentified in § 141.62(a) as a conditionfor granting a variance except asprovided in paragraph (c). If, after thesystem's installation of the treatmentmethod, the system cannot meet theMCL, that system shall be eligible for avariance under the provisions of section1415(a)(1](A) of the Act.


(c) If a system can demonstratethrough comprehensive engineeringassessments, which may include pilotplant studies, that the treatmentmethods identified in § 141.62(a) wouldonly achieve a de minimis reduction incontaminants, the State may issue aschedule of compliance that requires thesystem being granted the variance toexamine other treatment methods as acondition of obtaining the variance.

(d) If the State determines that atreatment method identified inparagraph (c) of this section istechnically feasible, the Administratoror primacy State may require the systemto install and/or use that treatmentmethod in connection with a complianceschedule issued under the provisions ofsection 1415(a)(1)(A) of the Act. TheState's determination shall be basedupon studies by the system and otherrelevant information.

(e) The State may require a publicwater system to use bottled water orpoint-of-use devices or other means as acondition of granting a variance fromthe requirements of § 141.61(a), to avoidan unreasonable risk to health.

(f) Public water systems that usebottled water as a condition forreceiving a variance from therequirements of § 141.61(a) must meetthe following requirements in eitherparagraph (f)(1) of (If)(2) of this section inaddition to requirements in paragraph(f)(3) of this section:

(1) The Administrator or primacyState must require and approve amonitoring program for bottled water.The public water system must develop

and put in place a monitoring programthat provides reasonable assurancesthat the bottled water meets all MCLs.The public water system must monitor arepresentative sample of the bottledwater for all contaminants regulatedunder § 141.61(a) the first quarter that itsupplies the bottled water to the public,and annually thereafter. Results of themonitoring program shall be provided tothe State annually.

(2) The public water system mustreceive a certification from the bottledwater company that the bottled watersupplied has been taken from an"approved source" as defined in 21 CFR129.3(a); the bottled water company hasconducted monitoring in accordancewith 21 CFR 129.80(g) (1) through (3);and the bottled water does not exceedany MCLs or quality limits as set out in21 CFR 103.35, 110, and 129. The publicwater system shall provide thecertification to the State the first quarterafter it supplies bottled water andannually thereafter.

(3) The public water system is fullyresponsible for the provision ofsufficient quantities of bottled water toevery person supplied by the publicwater system, via door-to-door bottledwater delivery.

(g) Public water systems that usepoint-of-use devices as a condition forobtaining a variance from NPDWRs forvolatile organic compounds must meetthe following requirements;

(1) It is the responsibility of the publicwater system to operate and maintainthe point-of-use treatment system.

(2) The public water system mustdevelop a monitoring plan and obtainState approval for the plan before point-of-use devices are installed forcompliance. This monitoring plan mustprovide health protection equivalent to amonitoring plan for central watertreatment.

(3) Effective technology must beproperly applied under a plan approvedby the State and the microbiologicalsafety of the water must be maintained.

(4) The State must require adequatecertification of performance, fieldtesting, and, if not included in thecertification process, a rigorousengineering design review of the point-of-use devices.

(5) The design and application of thepoint-of-use devices must consider thetendency for increase in heterotrophicbacteria concentrations in water treatedwith activated carbon. It may benecessary to use frequent backwashing,post-contractor disinfection, andHeterotrophic Plate Count monitoring toensure that the microbiological safety ofthe water is not compromised.

(6) All consumers shall be protected.Every building connected to the systemmust have a point-of-use deviceinstalled, maintained, and adequatelymonitored. The State must be assuredthat every building is subject totreatment and monitoring, and that therights and responsibilities of the publicwater system customer convey with titleupon sale of property.JFR Doc 87-14945 Filed 7-7-67; 8:45 am]BILUNG CODE 650---

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