" » •-•• .- \- <J L< v_ 'J ±

1989

.c We ;er Treat merit Rule)

Part II

EnvironmentalProtection Agency40 CFR Parts 141 and 142Drinking Water; National Primary DrinkingWater Regulations; Filtration, Disinfection;Turbidity, Giardia lamblia, Viruses,Leglonclla, and Heterotrophic Bacteria;Final Rule X

EPA Region 5 RecwdsCtr.

•IIIIIH254609

27486 Federal Register / Vol. 54, No. 124 / Thursday. |une 29.1989 / Rules and Regulationa

ENVIRONMENTAL PROTECTIONAGENCV

40 CFR Parts 14 land 142 *

IWH-FRL-3607-71

Drinking Water; National PrimaryDrinking Water Regulationa; Filtration,Disinfection; Turbidity, Glardla lamblla,Viruses, Legionella, and HelerolrophlcBacteria

AGENCY: Environmental ProtectionAgency (EPA).

ACTION: Final rule.

SUMMARY: Thii notice, issued under theSafe Drinking Water Act, publishesmaximum contaminant level goali forCiurJia laniblia viruses, and Legionella;and promulgate! national primarydunking water regulations for publicwater systems using lurface watersources or ground water sources underthe direct influence of surface water thatinclude (1) criteria under which Filtration(including coagulation andsedimentation, as appropriate) arerequired and procedures by which theSi ales are to determine which systemsmust install filtration, and (2)disinfection requirements. The filtrationand disinfection requirements are •trujtincni technique requirements toprotect against the potential adversehealth effects of exposure to Ciardialumblia. viruses, Legionella, andheterotrophic bacteria, as well as manyoilier pathogenic organisms that anremoved by these treatment techniques.Tins notice ulno includes certain limitson turbidity us criteria for (1)determining whether H public watersystem is required to Tiller, and (2)determining whether filtration, ifreijuired, is adequate.

DATES: Tins regulation is effectiveDIM.miller Jl, HIM. The Incorporation byreference of certain publications listedin the rule is approved by the Director of(he Federal Kejjuler us of December 31,19UO.

ADDRESSES: A copy of the public recordfor this rulemaking. including publiccomments on the rule and supportingdocuments, is available for review at theEPA Drinking Water Docket. RoomELMS. 401 M Street. SW., Washington,DC 2WGO. l-'or access to the docketmaterials, tall (JU2) 3U2-3027 between 9a.m. and 3:30 p.m Major supportingdiH.iiments cited in the reference suctionof Iliis notice are available forinspection ul the Drinking Wulut Supplytranches in KPA's Kegional Offices,listtid below.

I. JFK Federal Bldg, Room 2203, Boston. MA02203. Phone: (617) 505-3610. (cromeMealey

II. 26 Federal Plszs, Room 821. New York. NY10278. Phone: (212) 264-1600. WallerAndrew!

III. 841 Cheitnut Street, Philadelphia, PA10107. Phone: (215) 597-4873, Jon Cspscsts

IV. MS Courlland Street, Atlanta. CA 30369.Phone: (404) 347-2913. Michssl Uonard

V. 230 S. Deirbom Street. Chicago. JL 60604,Phone: (312) 353-2650. Joieph Harrison

VI. 1445 Ron Avenue. Dullut. TX 75702.Phone: (214) 665-7165. Thomat Love

VII. 728 Minneiota Avenue. Kanaai City, KS66101. Phone: (913) 236-2815. RalphLangemeter :

VIII. One Denver Place. 99918th Street. Suit*1300, Denver, CO 80202-2413. Phone: (903)283-1424. Marc Alston

IX. 215 Fremont Street. San Francisco, CA94105, Phone: (41SJ 974-0763. WilliamThuraton

X. 1200 Sixth Avenue. Seattle, WA 90101,Phone: (206) 442-1225. Richard Thiel

Copies of the latest draft GuidanceManual for Compliance with the SurfaceWater Treatment Requirements forPublic Water Systems ("GuidanceManual"). Regulatory Impact Analysis:Benefit* and Costs of the Final SurfaceWater Treatment Rule. Health Advisoryfor Legionella, Technology and Costs forthe Treatment of MicrobialContaminants in Potable WaterSupplies, and health criteria documentsfor Ciardia lamblia, viruses, Legionella,and turbidity are available for a feefrom the National Technical InformationService, U.S. Department of Commerce,5285 Port Royal Road. Springfield,Virginia 22161. The toll-free number It(BOO) 336-4700; the local number Is (703)407-4650.FOR FURTHER INFORMATION CONTACT:The Safe Drinking Water Hotline.

. telephone (600) 426-4701 (exceptAlaska) or (202) 382-5533 in theWashington, DC metropolitan area orAlaska, or Stig Regli. EnvironmentalEngineer, Science and TechnologyBranch. Criteria and Standard* Division,Office of Drinking Water (WU-S50D).Environmental Protection Agency, 401 MStreet. SW., Washington. DC 20460.telephone (202} 362-7379.

SUPF1CMENTARV INFORMATION:Table of Coolants

I. Lcsal AuthorityII. Background

A. Statutory Requirement!B. Regulatory History -~C. Regulatory Framework

III. Re*pon*e to Major laiuuaA. Determination of Source Wale* TypeB W.8 Percent Removal and/or

Iiiuctivatlon ef Ciardia CystsC. Conimuoui Disinfection vl the Entry

Point to iht DlHribuUon SystemO. Diiinfuclanl Roiduul in the Distribution

Syatcm

E Watershed Control and Oa-Sllaln»poctlon Requirements

F. Dciign and Operating Requirement*C. CT Values1. Unfiltered System*Z. Filtered SystemsH. Potential Conflict Between Today's Rule

and Future Rule* for Diilnfeclanti andDisinfection By-Product*

L Turbidity Monitoring and PerformanceCriteria

1. Urdlltared System*2. Filterud Synlemt

IV. Dcicripllon of the Final RuleA. Operator Personnel Requirement*D. Treatment Requirements1. Summary2. Criteria for Determining If Filtration is

Required(s) Source water quality criteria(1) Collform limits(2) Turbidity limits(b) Site-specific criteria(1) Disinfection requirement*(2) Watershed control requirements(3) On-»lle Inspection requirement*(4) Absence of woterboms disease

outbreaks(5) Compliance with the total collform

maximum contaminant level (MCL)(6) Compliance with the total

trlhalomethsnt MCL3. Criteria for Determining tf Treatment b

Adequate for Filtered Syetema(a) Ditinfection requirements(b) Turbidity monitoring requirements(c) Turbidity performsnca criteria(1) Conventional trtatment or direct

filtration(2) Slow sand filtration(3) Dlalomaceou* earth filtration(4) Other fillratlon technologiesC Reporting Requirements1. Unfiltored Sydsmsi Filtered SystemsD. Compliance1. Compliance Transition with Current

Turbidity Requirement*2. System* Uting a Surface Water Source •

(Not Including Syitema Utlng GroundWuler Source Under the Direct Influenceof Surf jet Wuter)

- 3. Syilcm* tiling « Ground Wulor SourceUnder the* Direct Influence of SurfaceWulur

4. Slruluylc* for ImplementationE. Public NotificationF. Variance*

"*- G. ExemptionsV. Stale Implementation of Surface Water

Treatment RequirementsA. Generalft Specific Primacy Requirement* for .

State* to Adopt 40 CFR Part 141. SubpartK—Filtration and Disinfection

1. Ccnerul Primacy Requirement*—StaleRequirement* Mud B* No LCI* StringentIhun Fuderul Requirement*

2. Special Primacy Requirement*—Slut*Requirement* Mutt Do Enforceable

3. Special Priinncy Requirement*—SidleMutt E*Ut>li»h Practice* 01 Pioccdurtt

C. Slule Reporting and RecordkcepingRequirement*

Federal Register / Vol. 54, No.1 T24 7 Thursday, Inne 29.1M9 / Rules and Regula t ions 27487

0. EPA Oertlght of Siole Decision*Regarding Filtration Requirements

E. Reiponie to Commend on PropowdRequirement! for Slate Implementationof the Surface Water TreatmentRequirement*

VI. Economic AnalyitiA. Total Coat of Final RuleB Concepta of Coil AnolyaliC Coiti of Compliance for Currently

Unflltered Surface Water Syitemi0. Cosli of Compliance for Currently

Filtered Surface Water Syvtem*E. Bcnefila

VII. Other RequirementsA. Regulatory Flexibility Ad0 fupcrwnrk Reduction ActC. National Drinking Water Advtiory

Council and Science Advlaory BoardVIIL References

Abbreviation! U$tdla Thit NoticeCFR-. Coda of Federal RegulationsCWS: Cpmmnnlty Waler SystemCT: Retidual DUtnfedant Concentration hi

mg/l ("C") X Disinfectant Contact Time In•mtn (T)

CTcalc Calculated CT ValueCTM«: CT Value Necessary to Achieve M.9

Percent Inactive lionEPA: Environmental Protection AgencyHPO Helerotrophic Plate ConntMCL Maximum Contaminant LevelMCLG: Minimum Contaminant Level GoalNfl-OWR: NaHonal Interim Primnry Drinking

Waler RefutationNPDWR: National Primary Drinking Waler

RegulaUonNTU Ncphelometrlc Turbidity UnitPWS: Public Water SyileraRIA: Regulatory Impact AnalysisRMCL Recommended Maxima

Contaminant Lire!SDWA or The Act": Safe Drfnldns, Watar

Act. aa amended hi 1986

L L0|tl Authority

EPA It promulgating this regulationunder (he authority of Sect. 1401.1412,1413,1414.1415.1410.144S. and 1450 ofthe Safe Drinking Water Act atamended. 42 U.S.C. 300f. MOg-1.900g-2.SOOg-3, 3008-4. 300g-6, 300J-4. and300|-fl. '

n. Background

A. Statutory Rtquinmtnlt .,The I960 amendments to the Safe

Drinking Water Act ("SDWA" or "theAct"). Pub. L 99-339, require EPA topromulgate a national primary drinkingwater regulation (NPDWR) specifyingcriteria under which "filtration" (definedin tectlon 14l2(b)(7)(C)(fl at Includingprelrestmenl measures such aacoagulation and sedimentation, asappropriate) la required as a treatmenttechnique for public water systemssupplied by surface water source*. Inestablishing ihese criteria, EPA mostconsider source water quality. ..protection afforded by watershedmanagement, treatment practices such

MI disinfection and length of waterstorage, and other factors relevant toprotection of health.

In lieu of provisions for obtaining avariance from the nitration requirementsunder section 1415 of the Act. EPA mustinstead specify procedures which theSlate Is to use to determine which publicsystems mast use filtration based on thecriteria that EPA establishes in thisregulation.

Notr Throughout chit preamble, the term"Stale" it died to mean a Stale with primaryenforcement reiponilUlity for public waterayitema or "primacy," and to mean EPA inthe case of a Slate (hat baa not obtainedprimacy.

Slates may require the publicwater system to provide studies or otherinformation io assist in thisdetermination. The procedures fordetermining whether filtration isrequired must provide notice andopportunity for public hearing.

ETA was to promulgate this NPDWRby December 19.1987. In March 1988.the Bull Run Coalition in Portland,Oregon sued the Agency for failure toIssue the rule by the statutory deadline.On January 17.1989, a consent decreecommitting EPA to promulgate this ruleby June 19.1989 was filed in the DistrictCourt of Oregon.

Within 18 months after EPApromulgates the NPDWR specifyingfiltration requirements, a Slate withprimary enforcement responsibility forpublic water systems must adopt anyregulations necessary to implement therequirement* of this NPDWR. Within 12months of the adoption of suchregulations, the State mutt makedeterminations regarding filtration forall public water systems supplied bysurface waters within its Jurisdiction. Ifthe State determines that filtration by apublic watet system It required, theState must prescribe a schedule for thatsystem that requires compliance within18 months of the determination.

The 1980 amendments to the SafeDrinking Water Act also required EPA.by June 19,1989. to: (1) Promulgate aNPDWR requiring disinfection an atreatment technique for all public watersystems (Including thcie served byturface water and these served byground water] and a rule specifyingcriteria by which variances to thisrequirement may be granted; and (2)publish maximum contaminant levelgoals and promulgate NPDWRs forJScontaminants listed In the AdvanceNotices of Proposed Rulemakhigpublished at 47 FR 9352 (March 4.1982)and 48 FR 45502 (October 5.1983). Thislist of contaminants Includes turbidityand five microbiological contaminants.Giardia lamblia ("Ciardia"). viruses.LegioneUa, Heterotrophlc Plate Count

bacteria ("heterotrophjc bacteria" or"HPC"). and total colt forms

B. Regulatory History

In the Advance Notice of ProposedRulemaking published on October 5.1983. EPA discussed issues pertaining toregulation of turbidity, Ciardia lamblia.viruses. LegioneUa. and HPC. as well asfiltration treatment for surface waterand disinfection requirements for nilsystems (40 FR 45502). On Novrmlirr 13.lOflS. F.PA proposed MC1.Cs forturbidity, Giardia lamblia, mid virusesand solicited comment on theappropriateness of establishing MCLCsand NPDWRs for LegioneUa and JtPC(50 FR 46936). (In this rule "viruses"means viruses of fecal origin which areInfectious to humans by wtterbometransmission. "Legionello" means agenus of bacteria, some species of whichhave caused a type of pneumonia callrdLegionnaires disease: the etiologic agentof most cases of Legionnaires diseaseexamined has been L pneumophila.)Public comments on these two FederalRegister notices and EPA's responses tothe comments are included in theResponse to Comments document in thepublic docket for this nilpmakinf(USEPA. MBftd).

On November 3.1R87. EPA: (1)Reproposed MCLCs for Giardia lambliaand viruses, and proposed an MCLG forLegioneUa: (2) proposed a nationalprimary drinking water regulationspecifying (a) criteria under whichfiltration (including coagulation andsedimentation, as appropriate) isrequired as a treatment technique forpublic water systems using surfacewater sources and procedures by whichthe State must determine which systemsmust install filtration and (b)disinfection treatment techniquerequirements for public water systemsusing surface water sources (52 FR42178). The proposed filtration anddisinfection requirements were Intendedto protect against the potential adversehealth effects of exposure to Giardialamblia, viruses. LegioneUa. andheterotrophic bacteria, as wrll as manyother pathogenic organisms that areremoved by these treatment techniques.The Novembers. 1907. notice alsowithdrew the November 13.19*5.proposed MCLG for turbidity andproposed certain limits on turbidity ascriteria for (1) Determining whether apublic water system Is required to filter;and (2) determining whether filtration, ifrequired. Is adequate.

On January 7.1908. EPA publ jhed cnotice extending the public commentperiod on Ihese proposed surface watertreatment requirements (53 FR 11192). On

27-180 Federal Register / Vol. 54. Nu. 124 / Thursday. June 29.1909 / R u l e s and Regulations

M.iy li. I'JllU. EPA published a Notice ofA v a i l a b i l i t y which solicited specificJ.jlu. diiuibscd alternatives to I lieproposed surface witter treatmentrequirements and solicited comment onihesc alternative options, anduYiigiul.:d July 5, 11MJ& as the end of thepublic ciiiuniunl period (53 FR 10346).('.. Flugtilulnry Framework

As explained in greater detail in thepro)Wb.il. this rule fulfill* the followingsi.ilulory requirements:

(1) The requirement that EPApromulgate a NPDWR specifying criteriaunder which filtration (includingcoagulation and sedimentation, ••appropriate) is required as a treatmenttechnique for public water systems usingsurface water sources, includingprocedures by which the State willdetermine which systems must installfiltration. Set section 1412(b)(7)(C).

(2) The requirement that EPApromulgate a NPOWR requiringdisinfection us a treatment technique forpublic water systems using surfacewater sources (EPA intends topromulgate additional regulationsspecifying disinfection requirements forsystems using ground water sources at aLiter date). See section 1412(b)(a).

(3) The requirement that EPA regulateCiurdia lamblia, viruses. Legiouella,hclerotrophic plate count bacteria, andturbidity. See section 1412(b)(l).(Colifornis are regulated in a separaterule published elsewhere in today'sFederal Register.)

(a) Ciardia lamblia cysts posesignificant risks to health for systemsusing surface waters, but usually not forsystems using ground water, becausethese protozoan cysts are removed fromwater by natural filtration processes inthe course of the water's passagethrough the ground. The turbidity level,which is u measure of particulale nutterin w.iier. is un indicator of therlfecliveiicss of treatment processesthat control pathogens, includingCiardia, in systems using surface water.Turbidity is not a useful indicator oftreatment effectiveness for mo*l groundwitter systems since most pwUcuialesure already being removed by Mturalfi l t rat ion processes In the course of thew.lid's pasijye through the ground.ll>.'c.iu*e lutural filtration processesremove turbidity and Cianlia fromground water. El'A believes thatpioniulyjl iun of this regulation, whichjpplius lo public water systems usingsurface vvaler sources (or, as explainedl.i lur. y iuund water sources under thuJuecl inilucnce of surface water) undincludes lurl i idi ty requirements, isii(!u(|u.ilu lo control lliesu contaminants.»u .iddition.il NI'UWRs to.ru)}til.ili!

Ciardia and turbidity in ground waterare unnecessary. Thus, it is EPA's

'position that today's regulation fulfillsthe SDWA requirement lo regulateCiardia lamblia and turbidity.

(b) This rule also provides protectionfrom viruses. LeyioneUa, and 11PC insurface water and thereby complieswith the SDWA requirement to regulatethese contaminants in surface watersystems. EPA intends lo promulgateNPDVVRs to control the levels of viruses.Legionella, and HPC in drinking waterderived from ground water sources.These regulations will be Included in thedisinfection requirements for ground .water sources. .

The criteria In this final rule aredesigned to control microbiologicalcontamination in general, not justCiardia lamblia. viruses, Legionella.and HPC. Since no waterborne diseaseoutbreaks have been Identified in ,properly designed, well-operatedsystems, U.. systems that meet thesecriteria, EPA believes that compliancewith this rule will provide significantprotection from most waterbornepathogens, including those notspecifically covered by this rule. Forinstance, EPA believes that filtered 'systems which comply with therequirements of this rule for suchsystems will provide significant . •protection from Cryptosporidium. aprotozoan recently implicated inwaterborne disease outbreaks.However, because of the currentuncertainty of the effectiveness ofdisinfection for InactivatingCryptosporidium. the degree ofprotection from this protozoan forsystems which choose to comply withthe requirements of this rule forunfillered systems may be more limited.EPA Is currently conducting studies todetermine whether additionalregulations may be necessary lo controlfor Cryptosporidium.

HI. Response lo Major IssuesIn this section. EPA describes the

major comments it received on theproposed criteria, which provisions ofthe /inol ruie have been changed Inresponse lo those comments, and therationale for those changes. EPA's moredetailed responses to the publiccomments appear in the Response toComments document in the publicdocket. (USEPA. I909b.) This section i«presented prior to the description of thufinal rule (Section IV) und assumes Ihcreader is farfiiliur wilh the proposedrule. Therefore, depending on interestund background, the reader may preferto either skip this section or ruudSection IV first.

A. Determination of Source Water T

Under the proposed rule, "surfacewater" was defined as

All wiler (1) open lo the ilmoiphere andsubject lo surface runoff, or (2) which Itdirectly Influenced by iurfoc* wsier. isdefined In (1). which may Include springs,infiltration galleries, or wells. Whether thereI* direct Influence by surface water must bedulcrminud on u cute-by-cuse boats. OiruulInfluunco muy be indicated by: (i) aignlficuniund relatively rapid shifts In watercharacteristics such as turbidity, larapaniiuru.conductivity, or pH (which may also changein ground water but at a much slower rate)which closely correlate to climalologic orsurface water conditions, or (ii) Un presenceof insects or olhtr macroorgaoisns. algae. . ;.organic debris, pr large-diameter pathogenssuch as Ciardia lamblia. ' . « • • • • • '

. i . , . . . • • • : - . - }••• •Some coramentecs supported the. :

definition because U would allow Stalesto require treatment to control forCiardia cysts, if such contaminationwere apparent, in systems using sourcestraditionally classified as ground water.Other commenters objected to thedefinition because II included aquifers,depending upon how the term "directinfluence by surface water" wasInterpreted. Aquifers, for the most part.are protected from contaminants, suchus Ciardia cysts, which are •characteristic of surface water supplies:thus, they argue, It is not necessary losubject these systems to this rule. Munycommenlurs were concerned that theproposed definition would require Slateslo evaluate all ground water systems lo ,determine whether they were under thedirect influence of surface water within30 months following the promulgation ofthe rule. Common(ers considered thisimpractical because of the limitedresources available to States.

EPA agrees thai most systems usingsources traditionally defined as groundwater are not al risk from contaminationby Ciardia cysts or other contaminantslypicully found in surface water. Theralu of reported wutcrborne outbrouksofgiardiasls in systems using groundwuter (as traditionally defined, i.e.,water not open to the atmosphere) Isabout 1/43 of (hot In filtered anddisinfected surface water supplies andubout 1/326'of that In unfillered surfuccwuter supplies (Craun, 1989). However,Ciurdia cysts do occur in some groundwiiler supplies due lo contamination bysurf/ice water (e.g., springs, infiltrationl-alluries, and wells; Iliblcr, 1987u).Therefore, EPA believes II Is appropriatell iul all ground water systems beevaluated, on a cuso-by-c.ise basis, forthe potential of contamination byCiunliu cysts. El'A believes that asystem nt significant risk from

Federal Register / Vol. 54. No. 124 /.Thursday. June 2U.1909 / Rulc« and Regulations 2740*)

conlamasation of Giardia cysls. i.e., aground water system unde^Jhe directInfluence ef surface water where the •structure oJ the lyttem cannot be•llered to reduce this risk, should berequired to comply with .the treatmentrequirements of this ruk to ensureadequate projection of public health.

Bused on information provided Inpublic comment* and furtherconsideration. EPA agrees that theitntutory tlmeframe for Stales to mnVefiltration dccUloni (I.e., 30 months frompiMndtatfon of this rule) does notprofide adequate time for States toeYalaata which ground wetersystemson tinder the direct Influence of surfacewater. IB addition. EPA believes themasl practical approach for Stales is tomake these determlnalions,whnn•antterjr sonreys are conducted pursuantto Ihe NPOWR for total coliforms(pubuabed elsewhere In lodny's FederalRegister] and/or when ground watersystems are evaluated for adequacy oftreatment aoder the forthcomingdisinfection requirements for groundwater systems,

EPA to also concerned that If a systemusing a craond water source werereclasaified ts a "surface water source"because the State determines II Is underIhe direct Influence of surface water, usdescribed ID Ihe proposal, such a systemalso would be required to comply withother regulations pertaining to surface-water supplies (e.g.. nnder otherNPDWRa. surface water supplies havedifferent monitoring requirements thanground water supplies). This may ormay not be appropriate, depending uponthe characteristics of the system,

EPA has addressed the aboveconcenu by nuking the followingchanges in the Gnafrule: .

a. The definition of surface water hasbeen shortened to "all water open to theatmosphere and subject to surfacerunoff."

b. The final rule defines a new term,"ground water under direct influence ofsurface water," as:

Any wHler beneath the surface of Ihe•round with (I) ilfntflcanl occurrence of(meets or other mtcroorsuiMms. algnc. orlarge-diameter palhofena Mch as Giordiatomblie. or (ii) significant and relatively rapidihifu In water characteristics such asturbidity, temperature, conductivity, or pi Iwhich ciotcly correlate to cllmalologlcnl orsurface water conditions. Direct Influencemuni be determined for Individual nources Inaccordance with criteria eilablished by theSlate. The State determination of directInfluence may be based on sn evaluation of•ilo-ipeclHc measurement* of wotcr qualityand/or well construction characteristics sndgeology with field •valuation.

c. When Ihe Slate revises Jts drinkingwater regulations lo adopt today's rule.

Ihe revisions must include a program furdetermining which systems using groundwater us a source are under the directinfluence of surface water (I) within Syears following the promulgation date ofthis rule for community water system*,and (ii) within 10 years following thepromulgation dale of this rule for non-community water systems. Theselimeframes are consistent with theschedule for conducting sanitarysurvey* under Ihe total collform rule,promulgated elsewhere In today'sFederal Register. EPA believes thesetime frames are reasonable because thesanitary surveys will provide much ofthe information necessary to make thedetermination.

d. All unfiltered ground wnter systemsthnt the State determines are under Ihedirect influence of surface wntcr must (i)begin monitoring 6 months following thedetermination lo demonstrate they aremeeting the criteria to avoid filtrationand comply with the requirements foravoiding filtration beginning 18 monthsfollowing the determination, unless theState determines that filtration isrequired, or (ii) install filtration andcomply with the monitoring andtreatment requirements for filteredsystems beginning 18 months followingthe determination that filtration larequired. This schedule Is explained Inmore detail In Ihe section entitled"Compliance." below.

Guidance for evaluating whetherground water systems are under thedirect influence of surface water will beavailable in Ihe final Guidance Manual.EPA recommends that infiltrationgalleries, springs, and shallow wells beevaluated first, then, depending uponaquifer characteristics, wells inincreasing depth. EPA believes that, formost ground water systems, onlyminimal analysis will be necessary lomake this determination. Simply put. if aground water system is subject toGiardia contamination (unless Ihecontamination originates within thedistribution system), Slatea shouldclassify it aa a source under the directinfluence of surface water and thussubject lo the treatment requirements ofthis rule. It is Important lo note that theintent of this rule Is not to regulate viraland bacterial contamination In systemsusing ground water, unless Giardia cjcstsare also associated with suchoccurrence. Thus, if there Is littlelikelihood for Giardia cysts to occur in asystem using ground water, but (here Ispotential for bacterial and viralcontamination. EPA does not expect theStale lo classify this source as a groundwater source under the direct influenceof surface water. Compliance with theNPDVVR for total coliforms (published

elsewhere in today's Federal Register)nnd/or the forthcoming disinfectionrequirements for disinfection of aroundwater systems will require adequatetreatment to address these otherconcerns.

EPA anticipates that while some •ground water system*, such MRinfiltration galleries, springs, and•hallow wells, may be under directinfluence of surface water In theircurrent configuration, in mnny cases, itmay be possible to mnke slruclurnlmodifications lo prevent the directInfluence of surface water and eliminatethe potenlial for Giardia cystcontamination, thereby avoiding therequirements of this rule.

Note: Thnmshmtt Ihe rnnnlndcr ot tM*prenmlilo, unle*s othrrwlno noted, we IK Iheterm "utirfncr wnlrr lyitrm*" *nri relatedterms to include both public wnier rntctnsufllng • surface water source anil publicwater systems using a ground WHIM sourceunder tbt direct Influence of snrfaos water.

B. 99.9 Percent Removal and/orInocUvalion of Giardia Cyst* .

EPA proposed to require alt systemsusing surface water to achieve at least a09.9 percent (3-tog) removal and (orinactlvatlon of Giardia lamblia cysts.Many commenlers thought itinappropriate lo require the sameminimum percent removal requirementfor all systems, regardless of differencesin source water quality and potentialrisk. Several commcnten suggested thatEPA allow exceptions to this minimumtreatment performance requirementbased on source water quality (e.g.. towoccurrence of Giardia cysts) and/orepldemlolofjeal widnntx of Irw risk.Some commenlers thought thai EPAshould base the treatment requirementupon some level of acceptable risk In thefinished water.

EPA continues to support therationale presented in the preamble lothe proposed rule for setting theminimum performance criteria of 99.9percent rcmovnl and/or Innctivntion ofGiardia cysts (52 FR 42194-42195).Furthermore, additional Information hnsbecome available to support thesecriteria.

Table 111 1 Indicate* pmtk nnd nvernenGiardia cyst concentrations in polluter!and pristine source waters of publicdrinking waler supplies (Rose, 1988).where waters contaminated withsewage and agricultural wastes werechnniclcriKCcl as "polluted" and watersoriginating from protected watershedswith no significant sources ofmicrobiological contamination fromhuman activities were classified as"pristine." The indicated concentration

27490 Federal Register / Vol. 54. No. 124 / Thursday. June 29,1989 / Rule* and Regulationi

level* reflect actual counts of cystsdetected without adjustment forinefficiencies in recovery (recoveryefficiencies were unknown for mostsamples). These data Indicate that, eventhough average cyst concentrations canbe significantly higher in polluted thanin pristine source waters, at least part of

the year peak cyst concentration levelsIn pristine waters can be the same orderof magnitude as the levels in pollutedsupplies. Occasional highconcentration* of Giardia cysts insource waters with protectedwatersheds may occur due tocontamination from animal populations.

Thus, during the part of the year whenthe water is most contaminated, i.e., theconcentrations of Giordia are thehighest, approximately the same level oftreatment performance is necessary fora pristine water source as Is necessaryfor a polluted source to provide thesame level of protection.

TABU lil.l—GIAPDIA CYST DENSITIES m SOURCES OF DRINKING WATER »

Typeotwaisr

w»iff| po%M4 ** tww «ntf sgrictAural wtnn , ,Pi.chn* Ml f , . ~

*>t <««i M«*P<W"« qu»jMy

Numtosrol

MmpM

139263

1,226

Numb*OlHtM

•71«

PtfGvnt 'petti*

tor .Olarda

4310

ae.4

Cvws/tooim

PMk

•39114100

Rang* ofIMWI

ttnctntra-tons*

OJ3-1040.6-6

0406-2.99

MMAOI•1

ooncwv•Mo***

> a: 04061

| ROM. 19881 P«c*n( ol it* Simpni* GMOMUC IMWI.

To date, in each reported walerbornedisease outbreak of giardiasis. at least0.5 percent or greater of the population(50 or more per 10,000 people or Sx10-*) were infected (Rose. 1B88). EPAbelieves that public water suppliesf hould provide much greater protection<han simply that necessary to avoid thisk'vel of risk from waterborae disease.I1PA believes that providing treatment tounsure less than one case ofmicrobiologically caused illness per yearper 10,000 people is a reasonable goal.This Is comparable to other acceptablemicrobiological risk levels (Rcgli el al.,liJOil).

Based on a recent rink analysis, whichiiisumc* nil cysts found arc viable andinfeciious lo humans, the incidence ofinaction from Giardia was predicted asd function of exposure to cystconcentrations in drinking wutcr (Rose,MMH). Tabled 111 2 unit 111.3 indiuilc thei l . n ly and annual risk from CiurJiuinaction fur people consuming finished

water with different Giardia cystconcentrations. The table* also specifythe level of treatment (I.e., 9-, 4- or 5-logremoval and/or inactivation of Giardiacysts) needed for source water withdifferent cyst concentration* to ensurethat the indicated daily and annual riskper person are not exceeded.

Comparing Table IIU with Table m.l,It appear* that water treatment plant*which provide 3-log removal and/orinactivation of Giardia cysts wouldgenerally ensure exposure to risk ofgiardiasis of less than 10"* (I.e., less thanone in 10.000 people infected) duringdays of worst case Giardia cystoccurrence (defined a* 250 cysts/100liters]. Comparing Table IJ1.3 with TableJH.l, It appears that water treatmentplants which provide 3- to S-log removaland/or inactivation of Giardia cyst*,depending on source water quality (e.g..for wulers with less Ihun 0.7 cysi*-/innliters and 3-log removal and/orInactivation, or water with less than 70

cysts/100 liter* and 5-log removal and/or inactivation), would generally ensurethat the risk of giardiasis I* lei* than10*' per year. Although EPA recognisesthat the above analysi* may beconservative. It 1* not unreasonablesince the cyst occurrence levels, asindicated in Table 111.1. may actually b#much higher due lo poor efficiencies ofrecovery. EPA believe* that 9- lo 5-logremoval and/or inactivation of Ciordmcyili represents a reasonable level ofprotection for the range of source we leicontamination expected to occur In theUnited States. Therefore, the final rulerequires that ell systems achieve al l«o*ia 3-log removal and/or Inacltvatlon i>fCiarJia cysts. In (he final GuidanceManual. EPA will recommend specificminimum performance levels In (he 3 iuS-log range, depending upon thevxpccfi'd degree of cyst conunilrmilniiin the source water

TABLE UI.2—ESTIMATED DAH.Y RISK Of GIARDIA INFECTIONS FROM VARIOUS LEVELS OF CYST CONTAMINATION IN DRINKING WAICHUSING AN EXPONENTIAL RISK ASSESSMENT MODEL '

Oafy rtsk p«r pwsofl •

10-»i .io-< . . -_10" »•i(f» «. , - - -

Cv»ieonc«nvs-inn <t 100

kMT»0«toMhMtwtMr

•07*0.25

00760.026

ABowtbM Cr»l conc*nv«uon « 100 kw*lOl *Ou>c« w*t«( 10 Krtf,» gw«o

KMtnwni fMuCMDS

• a-bfl

7.6x10*2.6x10*

7625

•4-tog

7*»IO«t»«IO«7.6k 10*28>IO*

6.100

JS.IO*a».io«76&IO*»i.»0§

> ROM. 1986• Astumua 2 W«r« ol w«Mr ooniunwd pur dey.• Uvol ol cyst* (Muctod dulng «*l«(boin« oulUMU ol oi*

in•

n

D)O

(M . .

•f*10

in

10

>

*>Uid

Figure III. 1INHCTIVRTION OF GIRRDIR CYSTS

BY DISINFECTION INFILTERED SYSTEMS IN WINTER

H H

03 Log)

* 4 I • • •< • <

10 50 90

Percent Systems <•» Log Inactfvation

99

<eto

H

i(9

2o

B

I

It

10<D

5"

3-.

§14

Federal Register / Vol. .54.: No. ie4, / Thursday. ) tmn 29.1909 / R u l e s nnd Rcguinlions 27491

TABLE 111.3—ESTIMATED ANNUAL RISK OF GIAROIA INACTIONS FROM VARIOUS LEVELS OF CYST CONTAMINATION IN DRINKING WATERf" USING AN EXPONENTIAL RISK ASSESSMENT MODEL '

Annul! ntk p«r perjon »

10-"10-< - ..10" *'10*'

Gtomelricm*«n ey»lconcenir*.l«nm 100

on* r**'

7x10"2x10-'

Allowtblc C^Ol MurC* wit

3. tog

200702007

II eoncemral'on in 10? Inn's

reoXictions

4 --log

JO702007

5 KX)

JOO70

7(

' ROM. 1988' AstumM 2 W«t Of otter COntumt l ptr (toy.

.The treatment performance levelscited above are consistent with what iscurrently being achieved by well-operated systems in the U.S. Figures 111.1Hnd II1.2 illustrate levels of Ciordia cystinactivatlon achieved by disinfectionalone during winter and summer

months, respectively, by typical filteredwater supplies in the U.S. (based ondata from AWWA (1987)). Assuming a2- to 3-log removal of Ciartlin cysts l>yconventional (rcntmnnt (which is usedby most of tho utilities represented inFigures II1.1 and III.2) without

disinfection, a total of at Innsi n- to A-logremoval and/or inacllvotion of Gmniiacysts from nitration and disinfectioncombined is generally nchievrd in writ-operated water trcalmrnl plants in IhcU.S.aiumo coot «ti« 10 m

in•ro

*-\ enO)O

(VI .O4*id

CO in

4* •"*O10

£ «"-L

Figure III.2INRCTIVRTION OF GIRRDIR CYSTS

BY DISINFECTION INFILTERED SYSTEMS IN SUMMER

1 1 »—i—i—i—i i i

<.5 Log

»»»»»»»»»»»»»-»>3 Log

<?5.

00

o

z

a.»

CDa><o

JO

a.»

OQ

+ + +

1 10 50 90

Percent Systems <* Log Inactivation

99

•auna COM *M*-M-c

M

to

274M Federal Register / Vol. 54. No. 124 / TburaJay, |. .ie 29,1989 / Rufes and

RPA believes it a inappropriate for(lie rule lo specify different levels oftreatment fa:different source waterqualities because it is generally notfeasible to confidently quantify Ciardta< yst concentrations. As explained in (heproposal, there is DO analytical methodfur measuring Giurdia lainblia cysts furwhich the preuaicn. efficiency, undsciuJtivity luve Lccn adequatelydefined; no reliable validationprocedures or laboratory certificationprocedure* «re available; and very largenumbers of samples would be needed toaccurately quantify Icveli of cystoccurrence.

Although some systems might notactually need • 3-log removal and/oriiiactivaiion of Giardia cysts to provideadequately safe water to theircustomers. EPA believes it is notfeasible fo» a system to demonstratewith assurance, e.g., with water qualitymonitoring results, that lower removulsand/or inaclivations would beadequately pn>Uctive of public health.Nor is Ihe historical absence of awaferborne disease outbreak asufficiently sensitive indicator thatadequate treatment is in place. Forexample, assuming that at least 0.5percent of Ihe population must becomeill within lets than one month to detectan outbreak, the ongoing absence of anoutbreak simply indicates that fewerllun 5 people per thousand become illduring any month. EPA also believesthat generally it cannot be demonstratedwith confidence that low levels ofwuterborne illness (e.g.. less than one in10,000 people per year) arc beingavoided bused on epidemiologicalanalysis of reported ilbiesacs to themedical community, since only illnesseswiih a si^nifican: adverse symptomaticresponse (end to be reported and suchreport* only represent levels of illnessamong mm-trunsienl populations. Also,levels of illness may vary significantlyfrom yeur lo year depending on the levelof conlanTinaiion und variations inpathogen strains which might occur inthe source water, and the level oftreatment provided. Therefore, to assurethat adequate protection will beprovided, the final rule does not allowsystem* lo achieve less than a 3-losjremoval and/or in.iclivatlon o! Giardiacysts.

C. Continuous Disinfection at the EntryPoint to the Distribution Syttem

EPA proposed to require that allsystems using surface water (bothuufilteieil und filtered) disinff't theirwater und continuously nioni r Ihedisinfectant residual entering Ihedistribution system. Under the proposal,each system would record the lowest

disinfectant residual coBcentratienentering the system each day. Any timethe residual was less than 07 rag/1, thesystem would be in violation of atreatment technique requirement. Thisviolation would be consider. >i "acute."thus requiring the system, ui..ier thepublic notification requirements in 40CFR 141.32, lo notify the public of theviolation within 72 hours via electronicmedia, as well as provide subsequentwritten notice, if it were a communitywaler system; non-community watersystems could substitute posting or handdelivery of notices. In response to thisproposed requirement, EPA received thefollowing comments:

• The short-term absence of adisinfectant residual at the entry point

. lo the distribution system should notautomatically trigger Immediate publicnotification since the actual health risks,depending upon site-specificcircumstances, may not be significant

• Continuous monitoring equipment Issubject to failure; such failures aregenerally beyond the control of theoperator. Thus, such failure should notbe classified as either • monitoringviolation or a treatment techniqueviolation.

• Continuous monitoring isunnecessary to demonstrate effectiveongoing disinfection and it will notresult in any increased health benefit.Crab sample monitoring every fourhours is sufficient for large systems; onesample per day is adequate endreasonable for snull systems.

• The cost for very small systems toinstall continuous monitoring equipmentis excessive (cited us about $5,000 forone analyzer and continuous recorder or$10,000 with another uni t us a backup)und muintcnance would be difficult.

In response to Ihe comments on Iheproposal, in Ihe May 6,1008, notice ofavailability. EPA solicited comments onvurious options for revising thecontinuous disinfection requirement.Most commenters addressing theseoptions supported the changes. Based onthese comments, and the reasonsexplained below, EPA lias modified theproposed disinfection requirements inIhe final rule as follows:

• If the residual is b»s than 0.2 mg/lfor any period of time, the system mustnotify the Stale es soon as possible tyilno later than by the end of the next"business day after It is first delected.

• If the residual measured is less than0.2 mg/l und it has nol been restored lo02 nig/I or higher within four hours ofthe first measurement, then the systemis in violation of a treatment techniquerequirement. Under the final rule, thisviolation is a Tier 1 violation (see the

public notification rules at 40 CFR141.32) but is nol defined as posing an"acute" heallb risk, so immediate publicnotification by electronic media, posting,or hand delivery (depending on systemtype) it not required unless the Statedetermines it Is appropriate.

• If tbcre is a failure in continuausmonitoiing equipment, grab samplingevery four hoars may be conducted forup to five wotking diiys following thefailure of the equipment. Failure k» usecontinuous monitoring equipment after(he five days lave passed is emonitoring violation.

• Systems serving 3.300 people orfewer may tale grab samples, at thefrequencies described below, la lieu ofperforming continuous moniloring'.

Syoaxn tfM by poputottm

I 10 1,000..1,001 to 1500.-

1 Pw dby't unpiM cannot »• Mcnar Irw MMr The umpwa rtmwt aw subject lo Stjw

approMSi

Note. If tb« residual Is leu t&an Olmt/tfcsny simple, thssystonmual taks aMthetgrab sample within four hoius,sf i*j*frsttumplt. If the residual hss nol beas> MStortdto 0.2 mg/l or higher, tfca syslasi mustcontinus to sample •> least svery (bur hoursuntil the ro»iuu«l ts mtortd to OJ mj/1 orhigher.

EPA believes the revised criteria willprevent unnecessary public notification.The Agency recognizes that somevysicms may save vary clean aouicewater and/or achieve excellentmicrobiological removal by filtrationand other treatment processes, wflhoulalways maintaining a disinfectantrekiduul of 0.2: rug/I or higher. Somesystems ilmt experience a briefreduction in their disinfection process.depending on source water quality andwhether other treatment processes arein place, may expose Ihe population losignificant health risk while others m«ynot. Thus. EPA agrees that it isinappropriate to categorically define •short-term reduction in the disinfectionresidual as a violation which poses an"acute" health risk, thus requiringImmediate public notification vieelectronic media, posting, or handdelivery (depending on system type).Instead. EPA believes that Slates shouldniuke these determinations asappropriule. Similarly, since all systemsure prone to operational failure at sometime, but not all such situations pose asignificant health risk. EPA believes thatsome lime interval should be allowed

Federal Register / Vol.' 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations 27495

for systems to restore (he disinfectantresidual rather then categoricallydefining this absence as a treatmenttechnique violation. EPA believes thatonce the system becomes aware (hot thedisinfectant concentration lerel Is lowor absent, four hours Is a renannablemaximum time intern) for operators toadjust and/or repair the disinfection ormonitoring equipment or to bring backupdisinfection or monitoring units on-line.

EPA agrees with the comtnenlcre thatfor some small systems, it may not btpractical to keep monitoring units Incontinuous operation. Therefore, In thefinal rule. EPA la allowing grab amnplingfor small systems. EPA believea Uralrequiring a minimum of one grab sampledaily will en tore that the operatorchecks on the disinfection procaM atleast once a day.

In the May 6»'l96&, nolle*. KPAsuggested thai grab sample monitoringonce per day be allowed for systemsserving 500 people or fewer. EPA alsosolicited comment on whether grabsampling should be allowed for somelarger system* aa walk Severalcommuters suggested that the. nil*allow grab sampling for systems servingfewer than 1300 people, but at higherfrequencies than required for systemsserving fewer than 500 people. EPAconsiders this suggestion reasonableand has modified the criteria in the finalrule accordingly.D. Ditinfeeteml Residua} fn theDistribution System

EPA proposed to require all systemsusing surface water Cboth Filtered andunfiltered] to maintain at leant a 0.2 rag/1disinfection residual In greater then orequal to 95 percent of the distributionsystem samples taken each month. If asystem Tailed to comply with thisrequirement for any two consecutivemonths, it would be In violation of atreatment technique requirement. Also.unfiltered systems falling to meet thiscriterion would be required to fitter. Thepurpose of this criterion was to:

• Ensure that Ihtr distribution systemIs properly maintained and Identity andllmft contamination from outside thedistribution system when It snlfhf ocean

• Limit growth of heterotroyhicbacteria and Ltgtonella wflUa thedistribution system: and

• Provide a quantitative limit which,if exceeded, would trigger remedialaction.

EPA proposed a minimum disinfectantresidual of 0.2 mg/l because It believedthat maintenance of nch levels aregenerally feasible for most weft-operated systems. However, publiccomments Indicate that, for manysystems which are v^ll-operated fas

evidenced by lovr levels of HPC Inro'.itine monitoring). It is not feasible tomaintain the proposed minimumdisinfectant residual withoutsignificantly changing existingdisinfection practice (e.g.. Increasingexfsting chlorine dosages or switching tochloramine disinfection for thedistribution system).

Based on these comments andadditional Information about currentdisinfection practice, EPA has revisedthe proposal. The final rule requires"detectable" residuals In lieu ofresiduals of at least 0.2 mg/L Inaddition, sites that do not have"delectable" residuals, but have HPCmeasurements of 500/ml or less, areconsidered equivalent to sites with"delectable" residuals forpurpoaes ofdetermining compliance. Thus, under thefinal rule, a system mny measure foreither disinfectant residual or HPC atany sampling location. EPA solicitedcomments on these options. In the May ft,1988, notice of availability (53 FR16352).and most commentera responding to thisIssue supported these alternatives.

EPA believes the absence of •disinfectant residual, rather than thepresence of a disinfectant residualbelow tome specific level is a moreaccurate indicator of potentialcontamination at a alia. The absence ofa residual at a site within thedistribution system Indicates that thedisinfectant level has been reduced.possibly as a result of localizedcontamination from outside thedistribution system (e.g., via cross-connections or back siphonage) or fromorganic or inorganic materials within thedistribution system (such materials,especially In the absence of a residualmay be of concern because they canoerve as nutrient* that enhancemicrobial growth). However, EPArecognizes that the abaence of adisinfectant residual at a distribution

' system site does not necessarilyIndicate microbiological contamination:such contaminants simply may not btpresent, even In the absence of*disinfectant residual. In other words. Ifmicrobial populations are low, the leekof a disinfectant residual Is not aconcern. Therefore, in the final rate,site* with HPC populations of 500/ml orless are considered equivalent to siteswith delectable disinfectant residualsfoi purposes of determining compliance.EPA believes the 500/ml HPC limit isgenerally feasible for most well-operated systems with well-maintaineddistribution systems and that waterbelow this limit Is unlikely to be subjectto localized contamination or significantmicrobial growth.

In addition to the changes describedabove. EPA has added several otherprovisions to the final rule. Somecommenters thought the proposedrequirement WAS Inappropriate forsystems which Introduce bothundisinfeclcd ground water anddisinfected surface water into the samedistribution system becsuse dilution bythe ground water (which Is presumablyclean and lhu»need not be disinfected)might lower the residual concentrationbelow 0.2 mg/l. In this case, they argued,the requirement was both Inappropriateand very difficult to meet. Therefore, foraystems which have both ground andsurface waters entering the distributionsystem, the State may allow monitoringfor disinfectant residuals at points otherthan the sampling locations for totalcol I forms if such points are morerepresentative of the treated(disinfected) surface water within thedistribution system.

For systems which cannot maintain adisinfectant residual In the distributionsystem, if the Stale determines, basedon site-specific considerations, thai •system hes no meana for having •aample transported and enalyzed forHPC by a certified laboratory under therequisite conditions (U., if analysiscannot begin within 8 hours on samplesmaintained at temperatures below 4* C.with the maximum elapsed timebetween collection and analysis undnr30 hours: API!A. 1985), and adequatedisinfection Is provided by that system,this disinfection requirement does apply.The State's judgment might be basedupon knowledge of the public watersystem's distribution system,maintenance of a cross-connectioncontrol program, source water quality,and/or past coHform monitoring results.

EPA added this provision for systemswhich cannot monitor for HPC for thefollowing reasons:

• The option of measuring HPCusually Is not available to small systemsbecause they generally do not have In-house laboratory capability to performthe analysis themselves and it Isgenerally not feasible to take samplesand send them to a private laboratorywithin the specified time limit, under theprescribed conditions.

• The integrity of the distributionsystem Is much easier to assess in asmall system than in larger systems.Also, the residence time in thedistribution system of a small system isexpected to be much lower than Inlarger systems, thereby minimizing thelime for bacterial populations to grow Inthe water.

Under (he proposed rule, a systemwould be required to Tiller if It felled to

27496 Federal Register / Vol. 54, No. 124 / Thursday. June 29.1989 / Rules and Regulation

11u.-t:l the criteria for maintaining adi»infeUjnt residual in the distributionsyiifffl. Cwmjiieiilurs objected to thisi niL-riun us n condition for avoidingf:/(raliou because the failure Co nic-cl thisui tenon might be caused bycontamination entering the pipingnetwork within the distribution systemrather than by source walercontamination and fdilure (o providefiltration. ERA has modified theproposed rule to address this concern.Under the final rule, systems are onlyrequired to filter if the fdilure lo meet(In: disinfection requirements for thedistribution system is caused by adeficiency in treatment of the sourcewater. However, any failure lo meet thedisinfection requirements for thedistribution system, regardless of cause,is still considered a violation of atreatment technique requirement.

EPA believes that the revised criteriafulfill the same objectives of theproposed criteria, but are more sensitivelo site-specific considerations.Compared to the proposed rule, therequirements in the final rule allowsystems (o use less disinfectant in thedistribution system, thus minimizingAdverse effects from disinfectants anddisinfection by-products. ID addition,total costs will be lower because fewersystem* will need lo institute majorchanges in current treatment to meet therequirement! of the final rule.

£". Watershed Control and On-SitcInspection Requirements

Under the proposed rule, to avoidMiration. systems would be required tomaintain « watershed control programwhich minimized the potential forcontamination by Ciardia lanibfia cystsand viruses in the source water thut wassatisfactory to the State. To avoidfiltration, systems also were required tohave un on-site sanitary surveypei formeJ each year that indicated tothe Stale's satisfaction that thedisinfection treatment process andwatershed control program wereadequately designed and maintained.

Some commenlers thought that theserequirements should be more detailed so.is to be mure easily enforceable. EPA.itfreen. Thus the finul nil* includes•idditiaitdl criteria which were lukenfrom EPA's October 8,1987 draft(Aiidance Manual ("draft GuidanceManual"), a a suggested by publici iiiimii iili.'is. Kl'A believes thul lliesM.1

revisions to l'ie proposal make thei r i l i M u more objective and thereforeinure enforceable.

KI'A has aUo changed the term"sanitary survey" lo "oil-situ inspection"in the final rule. Under the existingN.ilioii.il Primary Urinkmg Wali jr

Rugula lions, i.e., 40 CFK 141.2(0. *sanitary survey is defined as "an onsilereview of the water source, facilities,equipment, operation and maintenanceof a public water system for the purposeof evaluating the adequacy of suchsources, facilities, equipment, operationand maintenance for prod jcing anddistributing safe drinking water." EPAbelieves thai for the purpose ofavoiding filtration, it is not necessary forsystems to address concerns whichrelate to the distribution system; it issufficient that they consider criteriawhich relate to the effectiveness of thewatershed control program andreliability of the disinfection treatmentprocesses. Accordingly, the term "on-site inspection" in the final rule refers tothe evaluation of the watershed controlprogram and disinfection treatmentprocess.

Although this rule only requires in on-site inspection rather than a sanitarysurvey to avoid filtration. EPA believesthat all public water systems, Includingthe systems covered by today's rule,should periodically undergo the morecomprehensive sanitary survey, asdefined in 1141.2(0. to ensure regularevaluations of the distribution system as

* well as watershed and treatmentcharacteristics. Many Stales alreadyhave programs In place for conductingsanitary surveys, but at less frequentintervals than are required for on-siteinspections In this rule. Under the totalcoliform rule, published elsewhere intoday's Federal Register. EPA isrequiring small systems, I.e., thosecollecting fewer than five total coliformsamples/month, lo have periodicsanitary surveys. Therefore, forunfiltered small systems, during theyears when the sanitary survey Isconducted, the sanitary survey willfulfill both the sanitary surveyrequirement of the coliform rule and theon-site Inspection requirement of thisrule. In the final Guidance Manual, EPAwill provide guidelines for conductingboth on-site inspeclions and sanitarysurveys.

In an effort to streamline theregulatory implementation process forall the naw NPDWRs promulgated underthe SOWA amendments, EPA Isdeveloping guidelines for Stales to useIn making comprehensive vulnerabilityassessments of all public water supplies.The purpose of such un assessmentwould be lo evaluate Ihu vulnerability ofu system for all potential contamination(i.e.. microbiological, inorganic, andorganic contamination in the sourcewater, contamination within thetreatment train Itself because ofchemical addition, and contaminationwilhin the distribution system) and to

obtain information for determining themoil efficient strategy for bringing thesystem into compliance with allpertinent drinking water regulations.The on-sile inspections required underthis rule for unfiltered supplies wouldconstitute one aspect of thecomprehensive vulnerabilityassessment. . ;

F. Design and Operating Requirements

Under the proposed rule, all systemswould have been required to meetdesign and operating requirementsspecified by the State. Failure to meetany such requirement would b«considered a violation of • treotmenttechnique or monitoring requirement.Under i 141.32. all treatment techniqueand monitoring violations require publicnotification.

Most commenters thought It wasunnecessary to classify design operatingrequirements as Federal treatmenttechnique requirements since Slates 'already have such requirements (in fact,most States have permit systems Inplace), and if the system does not meetthe Stale-specified design and operating 'requirements, the system Is not allowedto operate. Many people commenting onthis issue thought that EPA should allowStales broad discretion to determinewhen public notification would beappropriate if a system failed to meetdesign and operating criteria imposedby the State. As an example, one •commenter pointed out that, under the .proposal, If a State required • publicwater system to monitor and meetturbidity performance criteria at aachindividual filter (rather than requiringthat the system only monitor thecombined affluent of all filtered water),and one filter of many within the systemfailed lo meet the criteria, or theturbidity monitoring equipment for on*filter failed, this would be a violation.The commcnler argued that It would notbe appropriate to require publicnotification In such situations.

EPA agrees with commenlers thatthere are likely to be many design andoperating criteria specified by the Slut*which, if not met, would not warrantpublic notification. Therefore, EPA hasdeleted from the final rule therequirement that systems comply withdesign and operating conditionsspecified by the State. However, El'Aliiis retained the proponed revision loPurl 142 requiring Status lo specifyenforceable design and operatingcriteria on a Statewide or lyslem-by-lyslein basis. Thus, while failure locomply with State-specified design andoperating criteria docs not constitute utreatment technique violation, «nd

Federal Register / Vol. 54. No. 124 ./ Thursday. June 29.19S9 / Ru'-« end Regulation* 271f>:

public notification is not required, suchH failure i* • violation oft Nile law.

C. CT Values

EPA received exlcruivc publiccomments regarding the basis for theproposed CT values, the method of theircalculation, and whether they should beinrlu-Jed In the rules or just published asguidance. Major issues that were raisedand how they have been addressed inthe final rule are discussed in thissection.

1. Unftllered Systems

(n) Calculation of CT voluex.- Under(he proposal, a system would berequired to calculate CT. where T* Isdisinfectant contact rime, the time Inminutes It takes the water to movebetween the point of disinfectantapplication and a point before or at thefirst customer during peak hourly flow,and ~C~ ii the residunl disinfectantconcentration in mg/l before or at thefirst customer but at or after the pointcontact time is measured. Manycommenlers thought this method ofcalculation was overly conservativebecause (a) significantly greiilerdisinfectant residuals might be presentat previous points in the treatment train,(bj most customers will receive waterthat has a much greater disinfectantcontact time than does waterat or priorto the Tint customer, and (c) applyingcriteria In the draft Guidance Manual,which states that contact time should hedetermined based on the rime It takeswater with 10 percent of the tracerconcentration to appear at the samplingsite, will result In much shorter contacttimes than under less conservativeguideline* (e.g.. contact time defined a*the lime it takes 50 percent of the tracerconcentration to appear at .the samplingsite), and thai such criteria areunnecessarily stringent

In the May 6, I960, notict ofavailability. EPA solicited comments ona different methodology to determine CTvalues for system* using ozone AU thecommenters who addressed this issuesupported the adoption Of thJs provisionin the final rule. In addition, manycommenters suggested applying thisprovision to all disinfectants. EPAagrees that this methodology, whichallows systems to determineincremental contributions to the totalpercent inactivalion based on a series ofCT measurements prior to the firstcustomer, results in a more accuratert prefer ation c-f actual disinfectionCd'rdiliC'.s, especially in systems havingsource waters with a high oxidantdemand, and those systems using ozone(because il dissipates very rapidly).Accordingly. EPA has adopted this

molhodologj^for all disinfectants in thefinal rule.

Thus, the revised methodology forciilriil.-iting CT in the final rule is asfollows: Systems may measure "C" atdifferent points along the treatment trainand use this value, with thecorresponding "T", to calculate the totalpercent inactivation. In determining thetotal percent inadlvation. the systemmay calculate the CT at each pointwhere "C" was measured and comparethis with the CTtt t value (the CT valuenecessary to achieve 99.9 percentinactivation) in the rule for specifiedconditions (pH. temperature, andresidual disinfectant concentration).Each calculated CT value (CTcalc) mustbe divided by the appropriate CTtt jvalue found in Tables 1.1-3.1 in the ruleto determine the Inactivatlon ratio. If thesum of the fnaclivation ratios, or

CTcalc

*• CT...

at each point prior to the first customerwhere CT was calculated is equal to orgreater than 1.0, i.e., there was a total ofat least P9.0 percent inactivation ofCiardto lamblia, the system is incompliance with the performancerequirement.

EPA expects the final GuidanceManual to retain (he recommendationthat systems determine contact timebased on the time it takes water with 10percent of the tracer concentration (Tn)lo appear at the sampling site at peakhourly (low. This approach is supportedby EPA's Science Advisory Board (1988).EPA does not believe that using • TUvalue, which was recommended bymany commenters, rather than a TMvalue, would provide an adequatemargin of safely since only 50 percent ofthe water, rather than 90 percent wouldreceive the contact lime necessary toachieve the percent Inactivalion the CTvalue represent*.

(b) CT values for chlorine. The CTvalues in the proposed rule were basedon animal infectivity data (Hibler et al..1987b) and application of a regressionmodel to these data (Clark et aL 1967:Regli. 1987). To provide a margin ofsafety, the CT vnlues to achieve 98.9percent inactlvatfon In the proposed rulewere set equal lo the CT values neededto achieve 99.99 percent inuclivalionunder experimental conditions.

Many commenters recommended thatEPA consider data obtained fromdisinfection studies using in vitrocxcyststion of Giarrfia lomblia(specifically, data developed by jHirollet al (1981)) lo develop the CT values In

the :"nal rule. Comrrirnlrr* indicatedIhni CT values bused on Ihc |;irrnll rl ;ilchit a would be significantly lower lh:mIhro" in the prnpmed r\ilr.

T';e CT vnlues in the finul rule .-in-based on a statistical analysis (Chirk rial.. 19I1B). whii:h considered bold amm-ilinfectivity studies (Ilililr-r et «L. inerli)and excystelinn studies (]<irroll rl ;il.1901: Rice et al.. 1902: Rubin. 19flnc| Amultiplicative model [the one previouslydeveloped for the anim.il infectivily diit.-ialone, which formed the basis for CTvalues in the proposed rule. Clark rl «L.10B?) was selected lo best rrprrsrnl Ihrchemical reactions during theInactivalion process. This modrl WHSapplied lo each of the data setsdescribed above, and in variouscombinations (Clark fit nl.. 1980). Thranimal Infectivily duta (Iliblrr ct o4..1907b) were included in each of thecombinations studied. The Hnimalinfcclivily data were consideredessential for inclusion in all thecombined data sets because, unlike theother data sets, these datn representedInaclivalioB levels grenler than 99.9percent Because of limitations with threxrystalinn methodology, only data onconditions necesnary for achieving lessthan 99.9 percent inactivalion wereavailable from these studies. Data atthese lower inactivation levels wereincluded in the analysis since the CTvalues in the rule may be used forcalculating partial inactiviilion levels(i.e.. less than 99.9 percent) which, intotal, are considered in determiningwhether the overall minimum level ofinaclivation of 99.9 percent is met.

Statistical analysis indicated thntcombining the Hibler et nl. |1907b) andJarroll et al. (1901) data ( and excludingthe Rice et al. (1982) and Rubin el al.(190Bc) data formed the best fit modelfor predicting CT values for differentlevels of inactivation. As a r.onsrrvnlivrregulatory strategy. Clark et nl. (1088)recommended that CT vnlues fordifferent levels of Inactivation bedetermined by applying first orrlerkinetics to the 99 percent upperconfidence Interval of the CT<n.tt vnlurspredicted by the model. For f'I' vnlursabove 5 *C. where dnta wrre limiled. llvauthors recommended that for rveryincrease of 10 'C. ih* CT viiluc brlowered by on* half. This rnnrrpt.which w.-is applied for clrtontiining thrCT values in the proposal nil«r. is alsosupported by lloff (19JW)

Accordingly, the bust fit model (bnsc<lon the Hibler et al (198~b) nnd |nrmll nal (1981) data) was applied, using thrabove two*concepts, to tlrtrrmine theCTt» t values in the finnl rule. The CIV «vnlues In the finnl rule are between ?.pro

27490 Federal Register / Vol. 54. No. 124 /, Thursday, June .29.19B9 / Rules and Regulations

.Hid ID percent lower than wh;il wiiaproposed. '

|t) CT values fur ozone. The CTv .ilues fur ozone in (he proposed rulewere baaed on disinfection studies usingin vitro cxcyslution of Giardia luinbliaI Wickramanayake ct at., 19115). CTMvalues ut 5 *C add pi t 7 fur ozone rungcdfiom 0.4U lu O.W. No data on Cl' valueswore avai lable for other pi Is at 5 *C.Therefore, lo obtain these data, thuhighest (Tin value. O.W. wasrUiapol.ili.'d using first order kinetics.nid mul t ip l ied by a sufcty factor of 3 toobtain the other CTȤj values in theproposed rule, as follows:

CT values at temperatures above 5 *Cwere estimated using (he tamemultiplier assumed for free chlorine, asdiscussed above. CT values at 1 *C orlower, for which no data were available,were estimated by multiplying Ihe CTNjv;i!ueat5'Cby1.5.

A much larger safety factor wasapplied lo Ihe CT values for ozone thanwas used to determine the proposed CTvalue* for chlorine because:

'• Fewer data were available forozont than for chlorine.

• The data available for ozone,because of the (imitations of thecxcyslation procedure, only reflect up loor slightly more than 99 percent .inactivotion. while the data for chlorinewas bated on animal infecllvily studiesindicating inoctivation at 99.99 percent(I libler et al., 1987b: Clark at al., 19W).Thus, extrapolation of data lo determineCl' values for 99.9 percent inactivutionusing ozone involved greater uncertaintythan the determination of CT values for99 <J percent inuclivation using chlorine.

• The determination of CT ul thuwater treatment plant also involvesyrealcr uncertainty for ozone than forchlorine because contact lime andresidual concentration cannot bemonitored us precisely for ozone.

• EPA believed that the proposed CTvalues, even with a large safety factor,would be practical to achieve.

Kl'A applied a safely factor of twoinstead of three to the laboratory data loubiain the CT values in Inn final rule.i.e., tliu Cl' values fur otune in the finalnile are two-third* of Incite in thuprupu*ed rule, because:

• The laboratory data which formedthe basis for the CT values used theludomeinc method for measuring ozone.Thu I'tdomclric method measures totaloxidanls present, not just ozone alone((-• g., tin* method measures ozonaiionl>y-producli such as hydrogen peroxide,which is a much weaker disinfectant•'.i in ozone). 'I lie final rulu)ru<|iiires..yii-nis to measure ozont:

Indigo method; this method measuresozone but nut other oxidants. Al thetime of these experiments, Ihelodometric method was Ihe onlyprescribed method for measuring ozonein Standard Methods (18th edition.1965). In the forthcoming 17th edition ofStandard Methods, however, Ihe Indigomethod, rather than the lodometricmethod, will be the recommendedmethod for measuring ozone. Since theoriginal Cl' values were bused on a "C"which may have included themeasurement of other oxidants inaddition to ozone, the CT values fromthese experiments are conservative. I.e..they are probably somewhat higher thanif ozone had been measured using theIndigo method.

. • According to public commentsreceived and further analysis by theAgency, the proposed CT values forozone in the proposed rule could only beachieved at very high costs.

Depending upon source watercharacteristic*. EPA believes that it willbe feasible for many systems to useozone lo meet Ihe revised CT values,and that these values provide anadequate margin of safety.

(d j CT values for chlorine dioxide.The CT values for chlorine dioxide inIhe proposed rule were based ondisinfection studies using in vitroexcyslation of Giardia murit cysts(Leahy, 1985). CT«* values at 5 *C andpH 7 ranged from 7 (o 18. The highestCTM value. 18, was used as the basis forextrapolation, using the same principlesas discussed for ozone, lo obtain theCTMJ values in Ihe proposed rule.

Limited data (i.e.. at 25 Tonly)Indicate that chlorine dioxide is moreeffective for inactivating Giardio niuriscysts at pH 9 than at pH 7 (Leahy, 1985).Because the data aro limited however,EPA proposed the same CT values forall other pHs.

Since the proposal, more data on (heconditions necessary for achieving 99percent Inactivation of Giardia muritcysls. using in vitro excyslation, hasbecome available al 1 *C. 5 'C, and 15 *C(Rubin, 1988b). These new data, plus Ihedata used lo develop the CT values inIhe proposal, were used to develop theCT values In Ihe final rule. The averageCT»t value at each temperature (27 .U ut 1*C. 11.U at 5 'C, B.S ut 15 *C and 4.7m 25*C) was extrapolated using first orderkinetics and multiplied by a safelyfactor of 1.5 lo obtain Ihe CT»»* values.Thus CU.. at 1 *C« 27.9X1.5 XI.5-63.Because of the limited data available atdifferent pi Is, the same CT values arcspecified for all pi is. Although most ofthe CTW data were determined al pit 7,it is known that chlorine dioxide is moreeffective ut pi I V. Tliu*. the Cl' values in

Ihe rule are more conservative for higherpi I* than for lower phis.

The CT values for chlorine dioxide inthe final rule are about one-third lessthan those In the proposed rule. EPAbelieves the revised CT values in therule provide an adequate margin ofsafety because of Ihe additional datathat was used, and because Giardiotnuris cysts, rather than Giordia lontbliiicysts (which Is the organism of concernin public water systems), were used inthe laboratory experiments. SinceGiordia niuris appears lo be moreresistant than Giardia lamblia lo •chlorine (Leahy et al., 1987) and ozone(Wickramanayake el al., 1985). ll i*reasonable to assume it is moreresistant to chlorine dioxidt as well.

(e) CT values for chloraminet—{\)Inactivation of Giardia cysts. The CTvalues for chloramines. based ondisinfection studies using preformedchloramines and in vitro excyslation ofGiardia murit cyst* (Rubin, 1988a; Regli.1987), are the same in the proposed andfinal rules. No safety factor was appliedto the laboratory data on which the CTvalues were based since EPA believe*that chloramination, conducted In theHeld, is more effective than usingpreformed chloramines.

In the draft Guidance Manual, EPAstaled that animal infectivity studiescould be used to determine the CTvalues necessary lo achieve 99.9 percentinactivalion of Giardia cysls. EPAbelieve* that other methodologies alsomay be appropriate. Therefore, in the .final Guidance Manual, EPA willrecommend that States also allow •systems lo use the methodology basedon //i vitro cxcyslation discussed byI (off et al., 1905. and more specifically,lo determine CT values for achievinggreater than or equal lo 99.9 percentinudivuliun of Giordia cysls usingchloramines. In addition, EPA willrecommend in the final GuidanceManual that Giardia murit cysls beused us a model for Giardia lambliacysls when conducting excystalionstudies because, as noted curlier,disinfection studies using excyslation lomeasure viability indicate thai Gianlitiniuris cysls are more resistant toinaciiviiiiun lliun Giordia lamblia cyituand thus provide a conservativeestimate of disinfection effectiveness(I (off. 1UU5): also. Giurdia niuris cyslsme apparently not pathogenic 10humans, and are thus safer lo workwith.

(2) Inactivation -of virttscs. Under theproposed rule. If a system used chlorine,ozone, or chlorine dioxide and achievedihl.9 percent inacllvatiun of dunlinr.ysts (i.i).. they ucliievud tlie Cl'

Federal Register / Vol. 54. No. 124 / Thursday. June 29,1989 / Rules, and Regulations 27499

In the rale). H was Assumed that itwould also nchieve grenler (nun 9BJ)Bprrccnl Imctivstion of vin»r»i.I lowover. the proposal explained that Ifa system used chloramiaes and wasable to achieve tht CT value* for 99£percent inacttvation of Ciordia cysts. Itcould not be assumed that 9&99 percentor greater Inacllvatton of rtrusca wasalso achieved

No minimum CT values, for achieving99.99 percent hiactivatlon of viruseswere included la the proposed rule.Instead, under the proposal system*using cnloramlnes for primary ; 'disinfection would be required roconduct on-site challenge srud:w rodemonstrate that they achieved at least99199 peiteul maentatlon of virtue*.

Since the proposal, new da ta h«v»become available which Indlr-** thaiI lepatitla A viras Is more sensitive thanCfardle cysts to Inactivatlon bypreformed chkramtnea (Sobscy. 1988).Thus, the CT values reqvired to achieve99.99 percent hiacUvarlon of Hepetflfe Awith preforTDcd chloramfnes are lowerthan Ihosa needed to achieve RR.9 •percent Inactlvation of Gfarriio cysts.These data contrast with other darawhich Indicate that rotavirus Is moreresistant than Giardio cysts topreformed chloramlnes (Hoff. 1969).However, rolavlrus Is very sensllive toinaclivatlon by free chlorine, much moreso than Hepatitis A (Hoff. 19M: Sobsey?1968). If chlorine is applied prior toammonia, the short-term presence offree chlorine would be expected toprovide at least 99.99 percentinacllvatton of rots virus prior to In*addition oTammorria and subsequentformation of chlotamlnes. Thus. EPAbelieves II Is appropriate to use theHepatitis A data, in lieu of the rotavirusdata, as a surrogate for determiningminimum CT vetoes for fnactlvntfon ofviruses by chloramlnes. provided thaichlorine is added to the water prior tothe addition of ammonia.

Thus, under the final role, a systemwhich achieves a 99.9 percent or greaterInactlvation of Giardio cysts withchloramlnes Is considered t* be>achieving at least 99.99 percentInacttvatton of vinsses, provided thatchlorine Is added to the water prior tothe addition of ammonia. If ammonia Isadded first, the CT value* hi the rule Torachieving 99.9 percent inactHrallon ofGiardio cysts cannot be considered1

adequate tor achieving 99.99 percentInactivatlon of viruses. Thus, under thefinal role. Ilka the proposal nthsystems must demon; '-ate, • seed on on-'site challenge studies, that the system fsa:hlevtnf al tost a 99.99 percent 'h activation of viruses. ColdjMieefor

conducting such studies will he providedIn thermal Guidance Manunl.

The proposed rule Included aprovision that excluded systems with nosources of human viruses within thewatershed from the 99.99 percent virusInHctivatlon requirement. This provisionwas based oo the fact that there were nodata available to Indicate that virusesexcreted by enfrrmls are pathogenic tohumnns. However, one commenter citeda «•-:!}• by Markwelt and Shortridge(19r •! indicating that a cycle ofwn' -• Some transmission andr? - *nance of influenza virus may< ;hfn duck communities mc- :n China, and that Hisc vable that virus transmissioncov. : occur in this manner to othertu«c»ptlble animals, including humans.Bused on the results of this study, theexclusion In the proposal has beenremoved. Thus, the final rule requires(hot all systems, even If there is nohuman activity within the watershed,achieve the mmlmum inecrhratlonrequirements Tor viruses.

(f) A tlematirv meant forrlenxmfratfng adequate disinfection. Inthe May 6.1988. notice of availability.EPA explained why CT values wereincluded In the proposed rule forunfiltered supplies but not Tor filteredsupplies (52 FR10357). EPA solicitedcomments on whether this rationale wasreasonable. Specifically, EPA askedwhether CT values for tmfilteredsystems should be placed In guidancerather than fn the rufa.

Moat comtnenters thought that all CTvalues shouM be placed In guidancerather than in the rule to more easilyallow for changes In CT values basedupon new data, and to allow Statesflexibility In their application.

EPA has retained the CT values forunfiltered systems in the final rulebecause (a) the Inclusion of CT valuesfor unfiltered systems makes the rule"self-Implementing'' and directlyenforceable, i.e.. a system that does notmeet the CT values must Installfiltration, regardless of whether theState has determined whether filtratloais required for a given system (see thesection entitled "Compliance.* below];(b) hi genera], unfitlered supplies are atmuch greater risk to water borne diseasethnn are filtered supplies (from 1971__through 1985. reported watcrbome "disease outbreaks and Illnesses were 8and 15 limes higher, respectively, fnunfrltered supplies with disinfectionthan in filtered supplies withdisinfection), so M Is important to haveself-hnprementmg. directly enforceablerequirements fet the rule for tech .systems: (c) without CT values fn the

ntlc for unfillrred supplirs, ihrre wouldbe no self-Implementing, directlyenforrenble provision lo ensure nnadequate level of disinfection isprovided (In contrast filtered system!*have self-implementing, directlyenforceable turbidity performancecriteria that indicate, at least in part, theefficiency of Giardio cyst and virusremoval): and (d) for free chlorine,which is by tar the most widely useddisinfectant, especially for unfiltaredsupplies. EPA does not believe new dntawill soon become available to provide abasis for concluding that tower CTvalues that will achieve the required••• vels of Giordia cyst and virus.^activation.

However. EPA agrees with•nmenters that the CT values for

. iorlna dioxide, oxone. and *••'"loramincs In the final rule are basedon limited dnla compared to the moreextensive data that provkte the basis forthe chlorine CT values and. that, foethese disinfectants, new data are morelikely to become available in the nearfuture that mny support different CTvalues or other means for determiningwhat percent inacttvation of GioroYocyst* and viruses a disinfectantachieves. For example, pilot plantstudies may show that the disinfectionefficiency of ozone, because of Ks rapidrate of dissipation, may be bettercharacterized by operational parametersother than CT. Also, a combination ofozone with ultraviolet light may beshown to be more effective than oxonealone In achieving the requiredinactivation efficiencies. As anotherexample. rbrcnJoramines. use of on-siteformation rather than preformedchloramlnes may prove to besignificantly more efficient than thelaboratory conditions In place during thestudies that are the basis for the CTvalues In this rule, In which case, lowerCT values may be appropriate (Hoff.1986).

Recognizing that research in this fieldIs ongoing, EPA has Included a provisionIn the final rule which allows anunfiltered system using a disinfectantother than chlorine (i.e.. chloramlnes,ozone, or chlorine dioxide) todemonstrate, by whatever meansallowed by the Slate, that II isconsistently meeting the 995 and 9H.09percent removal and/or Inoctlvotlonrequirements on a dully basis. Instead ofmeeting the CT values in the rule. Thismethod need not include use of CTvalues. For example, the efficiency ofozonatlon. under which disinfectionoccurs very rapidly, may best beIndicated by different operationalconditions (c.g.. applied dosage and

27500 Federal Register / Vol. 54. No. 124 / Thursday, |une 29.1989 / Rules and Regulations

mixing efficiencies) in place of.ur in addition to. CT values. Thisprovision is not provided fur systemsusing only chlorine because: (1) A largedjtj base was used for deriving the CTvalues in the rule and EPA believes thatnew daU are unlikely to becomeavailable soon to support the basis forothor CT values: and (2) the laboratoryexperiments on which the CT values arebused more closely simulate fieldconditions for chlorine than they do fordiloraoiincs. ozone, or chlorine dioxide.2. Filtered Systems

EPA proposed ihut filtered systemsdisinfect Ihcir water, und that theoverall treatment (i.e.. filtraliun anddisinfection) achieve at least 89.0percent removal and/or inactivation andU9.99 percent removal and/orinactivalion of Ciardia lamblia cystsand viruses, respectively. The Statewould determine whether the systemcomplied with this treatmentperformance requirement. In the draftGuidance Manual. EPA recommendedthat in general, filtration (with any „pfc treatment appropriate for the specifictechnology used) should be assumed tojchieve 99 percent (2-log) to 90.9 (3-log)removal of Ciardia lamblia-cytl* and 90percent (1-log) to 90.9 percent (3-log)romoviil uf viruses. Using thisassumption, EPA recommended that, to.ichieve at leusl 90.9 percent and 99.99IH.TCCIII removal and/or inuclivaiion ofLiardia lamblia cysts and viruses,respectively, with considerable marginof safely, a system that filters shouldprovide dikinfection which achieves atIr.isi a 90 percent (1-log) inactivation ofC.i-.inint lumblia cysts und a 94.9 percentO-!«K) imictivulion of viruses (higherli-vflsi of iiKii.iivjtion woreirMJiniinni(lei) fur tyalems with kourceiv tilery having vi.Ljmliuiiil lui.nl< iMiluiujiuiiun). r'ur must nyklcins, i.e.,iluiiit! which use chlunue, Cl' valueswhich achieve greater than a 90 percentin.iclivution of Ciurtliu lamblia cysts<:. in be expected to achieve greater than•i 09.99 percent inactivalion of viruses.Thus, a system which uses chlorine andiu.liieves greater thiin 90 percentiiMctivjliun of Ciardia lamblia cystswould be Hssunied ID satisfy the overallminimum performance requirement forviruses.

Most of the comments on CT values.mil the int'tliod of their calculationpertaining lo unfillercd supplies alsopertain lo filtered supplies. Thus, mostcummenlcri thought that EPA'siciuinmondod procedures for calculatingCT und (he actual CT values in the draftGuidance Manual were overlyt:onsm jiive. According to a surveyconducted by the American Walcr

Works Association (AWWA, 1987), only16 percent of the filtered systemsparticipating in the survey would beable to comply year-round with (he CTvalues recommended in the draftGuidance Manual, when calculated asrecommended. Many commentersthought that systems should gel creditfor inactivation of Ciordia and viruseswith disinfection prior to filtration,regardless of the level of turbidity(rather than limiting such credit tosystems with low turbidity), becausethese organisms are contained withinpaniculate matter, and therefore arcsubsequently removed by eithersedimentation or filtration. Somecommenters thought that Stales shouldhave broad discretion in how they applythe CT values in the Guidance Manualfor evaluating percent inactivations forfiltered supplies until the numbers arefield tested and evaluated on the basisof actual experience. In contrast,however, other commenters Hated that,for filtered systems, EPA shouldestablish minimum disinfectionperformance standards, in the form ofminimum CT values, in the rule (ratherthan simply making recommendations inthe Guidance Manual) in order lo assureuniform nationwide standards.

From 1971 through 1985, there werethree reported wuterborne diseaseoutbreaks in filtered systems attributedto inadequate or interrupted disinfectionversus 10 outbreaks duo lo inudequtafiltration or pretrcalmcnt (in contrast lounfilicred supplies where there were 42reported outbreaks due to inadequate orinterrupted diiinfeclion) (Craun. 1UHO).Although EPA strongly believes thesestatistics reflect only a imull proportionof the disease outbreaks and illnessesticlually occurring. EPA also believesIhut these data iiulicjlii. in geuunjl, llnilmost filleted nyntuiiiii. ivheu well-operated, are providing adequate levelsof disinfection lo protect fromwulerborne disease. Dated on a reviewof these data and public comments, EPAbus concluded that the many safetyfactors that it recommended in the draftGuidance Manual for estimating thetotal removal und/ur inactivation ofCiardia cysts and viruses in filteredsystems, like the sufety factors built intothe requirements for unfillerud systemswere, in total, overly conscrvalivu.

In response, the following changeswill be made in the final GuidanceManual to address these concerns:

• In (he draft Guidance Manual, EPAhad recommended that credit towardCiardia and virus inactivalion In thewater prior to filtration be allowed onlyIf the turbidity of that water is less than5 and 1 NTU. respectively. The final

Guidance Manual will recommend ihutcredit be given for disinfection ofCiurdia cysts and viruses prior lofiltration regardless of the turbiditylevel. This recommendation Is based onthe assumption that sny pathogenspresent in the source water will beeither removed by filtration or directlyexposed to disinfection.

• The final Guidance Manual will"recommend that. In general, systemsusing conventional treatment which areable to achieve turbidity levels of lessIhun O.S NTU in the filtered water in 05percent of the samples be assumed toachieve 2.5-log removal of Ciordia cystsund 2-log inuclivaiion of viruses,provided that coagulation andflocculalion conditions are optimized forturbidity removal by filtration. Thesesystems would thus only need toachieve • 05-log Inactivation of Giardialamblia cysts and a 2-log inactivalion ofviruses with disinfection to satisfy theoverall 3-log and 4-log minimumperformance requirements. EPA believeslhat these revisions are approprial*since sedimentation and filtration(preceded by coagulation) provide moreremoval of Ciardia cysts and virusesthan does filtration (preceded bycoagulation) alone. This conclusion Isbused on two recent studies. In pilot •plant studies using Ohio River water,Logsdon (1985) has shown thatsedimentation achieves 0.5- lo 1-logremoval of Ciurdio cysts. Since filtrationprovides 2-log removal, it is appropriateto assume that sedimentation andfiltration together provide al least U-logremoval. In addition, in pilot plantstudies using Lake Houston water, Raoet al. (IQUtt) have shown thatsedimentation (preceded byuiujjiilulion) achieves generally greaterlinn) !X) percent removal of viruses andlhii! nediiiiciilution mid filtrationloyellier generally achieve greater than•M percent removal of virukcs.

• The CT vulues for free chlorinehave been lowered up lo 10 percent, forthe same reasons discussed above forunfiltured supplies.

• The CT values for ozone andchlorine dioxide have been lowered byubout one-third, fur the tame reasonsdiscussed above for iinfiltered supplies.

» Kegurding the use uf chloraminct,(he final Cuiduncu Manual willrecommend thai, in general, for thereasons discussed above for unfiheredsystems, filtered systems which addchlorine to the water prior to ammoniaaddition be assumed lo be achieving09.99 percent removal and/orinuctivation of viruses if they oreachieving 09.9 percent removal and/orInactivolion of Ciardia lamblio cysts.

Federal Register / Vol. 54. No: 124 /'Thursday. June 29.1909 / Rules and Regulations 27501

This is a change from the dmft GuidanceManual which recommended thai allsyslrms using chlorfimhies (or primary «disinfection demonstrate the adequocyof virus Inactivation baaed on on-iilechallenge studies. For systems whichadd ammonia to Ihc water prior tochlorine, the final Guidance Manual willcontinue to recommend on-iilechallenge studies to determine theadequacy of disinfection for virusInactivation.

Figures III.l and IH.2 indicate thelevels of Giordio lamblia cystInactivation thnt filtered systems In theU.S. are currently achieving fromdisinfection alone, assuming the criteriain the final rule and final GuidanceManual for calculating percentinactivation were implemented. EPAestimates that 10 to 20 percent of filteredsystems will need to augment existingdisinfection in order to comply with thiifinal rule and to meet the criteriarecommended In the final GuidanceManual. This Is a large reduction fromAVVWA's estimates that 82 percent offiltered systems would need to enhancetheir current disinfection practice tomeet the criteria In the proposed ruleand the draft Guidance Manual(AWWA. 1987).

H. Potential Conflict Between Today'*Rule and Future Rule* for Disinfectantsand Disinfection By-Productt

EPA Intends to promulgate nationalprimary drinking water regulations toregulate levels of disinfectants anddisinfectant by-products for all systemswhen It promulgates disinfectionrequirements for groundwaler systems.Many commenlers expressed concernthat changes that systems might need tomake in their disinfection practice inorder to comply with today's final rulemight be inconsistent with the treatmentchanges necessary to comply with theseforthcoming regulations for disinfectantsand disinfection by-products. '

EPA believes that many of the specificconcerns expressed by commentcrshave been substantially mitigated by thechanges in the final rule and plannedchanges in the final Guidance Manualdiscussed previously. Aa a mu)t ofthese changes, EPA believes that manysystems already are in compliance withtoday's rule, so changes In disinfectionpractice will not be necessary. Inaddition, under the final rule, the Statehas discretion to determine whatdisinfection conditions are needed forfiltered systems to meet the 3- and I logremoval and/or Inar.tlvatlonrequirements for Ciardia lamblia cystsand viruses (or any hlghenfevel ofperformance thai might be specified bythe Slate, depending upon source water

quality condil«#is). In exercising this 'discretion, the Slate could take intoaccount any potential conflict withforthcoming regulations for disinfcctHnlsand disinfection by-products. Forexample, if a system using conventionaltreatment is well-designed and isoptimizing its clarification processes forturbidity removal, and is achieving verylow filtered water turbidities, It may beappropriate for the Slate to give thatsystem 3 logs of credit for Ciardia cystremoval (in lieu of the generallyrecommended 2.5-log credit); In thisway. the system can avoid substantial(if any) upgrades in disinfection practiceand. in turn, potential increases Inhealth risks from higher levels ofdisinfection by-products. In the finalGuidance Manual. EPA expects torecommend that States give credit for 3logs of Ciardia cyst removal byconventional treatment only If: (a) Thetotal treatment train achieves at least 09percent turbidity removal, or filteredwater turbidities are consiatently lessthan 0.5 NTU, whichever results inlower levels: and (b) the level of HPC inthe finished (disinfected) water enteringthe distribution system it consistentlyless than 10/ml.

In general. EPA believes that filteredsystems need to achieve O.S- to 1-loginactivation of Ciardia lamblia cysts(depending on the type of filtrationused) to achieve an overall 3-logremoval and/or inactivation. However.it may be appropriate to allow morecredit for filtration and thus require lessdisinfection, e.g., less than 0.5 logs forconventional treatment, until regulationsfor disinfectants and disinfection by-products are promulgated and theoptimum treatment for achievingcompliance with both regulations can bedetermined. However, EPA recommendsthat these lower levels of disinfectiononly be allowed if the source water itexpected to have concentrations of lestthnn one Ciardia cyst/1001. Likewise,for systems using slow snnd filtrationand diatomaceous earth filtration. EPAbelieves it would nol be unreasonablefor Stales to allow U or 3 logs of creditfor Ciardia cyst removal in lieu of thegenerally recommended guideline of 2togs of credit, depending upon sourcewater quality and concerns about ~~disinfection by-products. Pilot plantstudies have demonstrated (USEPA.1988b) that these technologies, whenwell-i peraled, generally achieve theseremovals or better. Assuming thesetechnologies achieve only a 2-logremoval, at generally recommended byEPA for the purpose of determining the. . oropriate level of disinfectionnecessary for the system to meet the

overall treatment performance standard,provides a very conservative margin ofsafety to control for microbiolosicalconcerns. However. EPA rrcognirrs tinsassumption may nol nlw.-iys boappropriate depending upon sourcewater quality, reliability of systemoperation, and potential increasedhealth risks from disinfection by-products. Thus, the final rule does notdictate how the Stale must calculatetreatment efficiencies for filteredsystems; it is left to Stale discretion.

In the final Guidance Manual EPAplans to recommend that States allow,for the interim (i.e.. between now andthe time EPA promulgates regulationsfor disinfectants and disinfection by-products), more credit for Ciardia cystremoval (and. in turn, virus removal)only if it determines that a system In nolcurrently at aignlficnnl rink frommicrobiological concerns at the existinglevel of disinfection, and that a deferralIs necessary for the system to upgradeIts disinfection process Jo achievecompliance with this rule as well as theforthcoming regulations for disinfectantsand disinfection by-products. Since EPAintends to regulate disinfeclantt anddisinfection by-products by 1991 (see S3FR1899). and compliance with today'sfinal rule for filtered systems Is notrequired until June 1993, it is anticipatedthat most of such systems will havesufficient time to optimally address therequirements of both rules.

EPA does not believe (hat the samediscretion discussed above for filteredsystems is appropriate for unfiltercdsystems tince (a) they arc at muchgreater risk from walcrbomc diseasethan are filtered systems, (b) SOW Arequires that the Slate determinewhether filtration is required within 30months following the promulgation ofthis rule, and the Slate cannot make thedecision whether filtration is necessarywithout knowing what disinfection willbe in plnce. Also, the Institution nffiltration by an unfillercrl supply allowsa syslem to use much lower levels ofdisinfection Irian is necessary in asystem without filtration: as a result. .levels of disinfectants and disinfectantby-products are lower in filteredsystems, assuming the some sourcewater quality conditions.

/. Turbidity Monitoring andPerformance Criteria

1. Unflllered Systems

EPA proposed that, to avoid filtration,a system demonstrate on an ongoingbasis that the turbidity of the wnlerprior to disinfection does nol exceed 5NTU, based on measurement* at least

27502 Fed*ral Register / Vol. 64. No. 124 /' Thursday! June ^'J,l!ir,U"/ Kuli:s and Regulation*

I ' v i T y four liujn. Uiidi:i (he pn)|(osdl. ao}ni.:in wuulj nui be required lo filler ifii ou-afciotuiJly exceeded the 5 NTU limit|.ilthuin;h such an exceedunce would bei imsuWfd * v.ulaa'on uf the Inulmcnt

- ret^itrtinu.'nts which posed in.risk ii» human health). Specifically,

.1 syiiuiu could excet.-d the 5 NTU limitno inure lluin two jwnotls during hvi:lve• iiiiitcutive month* or five periodsduring \2(i consecutive month*, providedih. i i (a) the system informed its(.i^lomefi and the Still; of the violution,•is soon a* possible but in no cane lateri):.m 72 b';w* after the violationuccurre*!. arid customers ware intrudedtu bi.il tlM:i.- v*»itit before consumptioniinii i it \v.is determined that th« waterwas »ufi'. and (Ii) die Stale determinedthat the exceedjixe occurred became ofunusual w unpredictable circumstances.A "period" would be defined as a tenetof consecutive day* in which at leastone turbidity measurement each dayexceeded 5 NTU.

Sonic cummenurs wert opposed toalluwmg any period* when turbiditiesrxceeded 5 NTU tii>i;e systems are raoitvulnerable to microbiological rink at.•-wli times. Others thought thai thuperiods in which turbidity could exceedS NTU ihould be limited in duration,Snme comifli.-nieni ttuted that anabsolute limit LJI turbidity waninappropriate since the significance ofturbidity level* as no. indicutof ofpossible interference with disinfection

on (he size and. chemicalof the paniculate mailer

t. Other rommenlers supportedi i i u proposed Uiihidily limit*. Somei miimenlers opposed the propos.il lo< l.ubli'y un exrecdiince of 5 NTU at an.M:U:O hc..!lh risk kiiii.e high lutbi'lily> ! . > < 9 not nuucssarily iajiculc a healthli.r^.ird. di:peiuliny on the nature! uf thu(Liiliculalt; tu.iHci uiioenl. Similarly.i'..-y obJLM.lud In the propotal ibuls> steins issue j boil water nolit^- lo theimli l ic whenever the turbidity exceeded5 NTU; muny lhuu>jhl that such Miri|uin.'in<:nl kltoulil l>«t Uft tu Stall)ill i,:rt:(ion L.isi:d uyuiii itu uvuluitliuil of ..11 l i idl hujllh rijk.

In the linul rule. EPA has retained theI-lovii i ion th.il allows lUsfillereJ nyslemjin exceed thu lui l j i i l i ty limit of 5 NTU aSmiled nuMi'ni.-r of liini.'t. i.e.. no moreIti,in Iwj ij'.xsili Jtiriug 12 L0i)aei:ulivui i i < i i : l h < (>r fix ir evoiiln during 120LOiiser i i l ivc ii i . i i i l i isi , ;is long as Ihu Sluti;is ir.fjrnicJ ul u.it-h cxctedance and(L'lurniir iL'b tli . i l ii wus causud byiniukkial or unpredictable circumstances.(la Iliu final rule. EPA u»e» the term"event" ruiher than "period.'T EPAlii.'liuves lh.il (hv other requirements for,n.unlmjj f i l l r i i l ion in Ihe rule unmirt! n

i probability trjut adequate Iruaimentis s t i l l being provided if the turbiditywere lo exceed 5 NTU for short periodsof time. These include the requirementsto (a) comply with fecal or total coliformsource water quality limits; (b) maintaindisinfection condition* sufficient loachieve at least 9».9 and 99 9» percentinuclrvation of GiunJiu tamblia cystsmid viruses, respectively, as indicatedby meeting the CT requirements: (c)comply with the total conform MCI. (thecoliform rule, published elsewhere intoday's Federal Register requiresunfiltered surface-wu(era ID rakecoliform- measurements at or near thefirst customer on-days when theturbidi ty exceeds I NTU and lo includethese measurements in the MCLcompliance determination): and fd)maintain a watershed control programto restrict human-activities. Therequirement to hove a watershed control'program reduces the probability thaihuman- viruses wilt be present in largenumbers, so there is less concern aboutturbidity interfering with disinfection ofviruses. In addition, there is much lestconcern about turbidity interferiug withinactivarion otdardia cysts bydisinfection than viruses or bacteriasince Ciordia cysts are much larger thanviruses and bacteria and are lets likelylo be occluded or protected byparticulate natter:

The final rule does nor specify «maximum duration for »turbidity event;as a condition for avoiding filtration,since olher requirements (discussedabove} muni also be met taavoidfiltration; EPA expects that, if theduration of an event is long, and* thesystem is at risk (which will depend onthe mi i ure of the ponicuhile muttercausing the high turbidity level, and thesource witter quality), one of the oiherrequirements for avoiding filtration islikely Ic be exceeded, thereby requiring(he system to install filtration.

KPA agrees with public communismwho staled that interference withdisinfection by turbidity will drpcnd on(he nature of lite paniculate matter thatis present. However, es discussed in theproposal, EPA believes nn upper limit of5 Nil) is appropriate. Increases inturbidity occurrence levels hum lessthan 1 NTU lo greater thun 5-10 NTl l»-hiivc been shown to correlate withdecreases in disinfection cffixlivcn.riisin uufi l lered source waters (Le Chi:\alit.-rel ul.. J'jei). Irrmldition. high turbiditywaters may be'unaesthotic inappearance and cnu»n consvimers loavoid use of the public wulcr supply andpossibly choose less safe waieiv

The requirement that systems ii.f.irnillii.-ir customers to hoi I (heir tv.ili-r

bcfocc consumption wliun $oun:i; w.il.irturbidities exceed 5 NTU has bcrodeleted from (he HniJ rule. EPA agreeswith the commenters ihaJ States shoulddclerrr.ine if such an order khouulbeissued, sfnce certain site-speciHc factorsmight nol warrant ruch actioa. Also, inI hi; final rule, an excecdauc* oflbelurb id i ty limit of 5 NTU u considurcd aviul.ilion of a treatment techniquerequirement, but not. as proposed.OHMwhich poses an acute- risk u> humanhealth. Therefore., violution of. the5 NTUlimit does nol rebuke a sysutm to notify(lie public via electronic.madia, polling.01 blind delivery .depending ou kytUtnitype, within 72 bouts. (Only writtennotice i* required, at specified Cor T.MI 1violations. See tlia, public notificationregulations at-U CFR 141J2.1

2. Filtered Systems

KPA proposed to require- syslam* thatRlter to measure-the lurbidily lex-el of ariipreMBUlive lavnpla of filliictd'woufrrvcry fuur houc» whni» water tabuingJcuveied lo<lhedjtf(ribulioatystuisu tor<i system u*ing eonuentioiuiLlrearmoiUor direct nlualioo, EPA peopoaed u>rui|uirc that the turbidity UtvcIoCtkcsystem's Hilt-red walcr be Ihsa trunari.-qual to 0.5 NTU in at least U&purcanl.ofthe measurement* taken each month.Fur a system using slow sand ordiatomaccous earth filtration. EPAproposed lo require lh.it (he turbiditylifve* be less-than! NTU fn »llu*»t» >ptTcenl of the measurements taken enrJimonth. Under the proposal, for systems-n»ing conventional rrcdtmanfor dlreeffillranon, if lh« StiUt detunixineJ Ihuroil-site studies demonstrated at leirtr9U.9 percent uveraH removal and/orin.iutivation of Cfnnliii oysti. (he Stnrrcould specify a highiir li.Hiidiry limit, opti> > NTlf in t>6 |>ert:rnt <)f thu siimpli>» ina month-.

Muny coinmenreni. especialbj-1 howretire-seining small syilmns. f.ivormlretaining lhi> current turbiditymoil i toting requirements iu the inli:riniicKulalions, I.e., one sample per iLiy (40CI'U ur.22t Comincnturs JaiuicJ lluilmnii i loi i i ig of turbidity every four hours,ur by continuous monitoring anilri!i:ui'ding uqiiipnient. it not feasible furNII I . i l l syslt-nu. fn addition, oumy<:ommi:nti:cu ubjiiclud lo Uu: 0.5 NTUUntil for syslt'ins nsip.K cimventioiulIrcalmenl or direct fillraliou: tliuyfiivored retaining the exjsling sUiuLit-dof I NTU. Some commence* slaluilthere is no evidence thai tlui raorcNtringniit lurbulily criteria El1 A uioponudwould result in iucixuscd. bualthprotiiclion. i.e.. feu-cr waterbuutuilixiMUiu oulbrcalui. compared, la lh«ir\i.-,linn lurbidily MCI, Coninii-nh'i*

Federal Register / Vol. 54, No. 124 / Thursday. June 29.1909 / Rules and Regulations 27503

stated that many systems, especiallysmaller systems, would Incur.significantcosts to make treatment changes tocomply with the proposed turbiditycriteria. In a survey by AWWA (1087).which sampled mostly large systems. 24percent of the filtered systems whichresponded did not have filtered waterwith tu rb id i ty less than 0.5 NTU 95percent of the lime.

Some commcnters supported the 0.5NTU limit, claiming II wouldsignificantly improve the quality ofdrinking water nationwide. Othercommcnters supported the O.S NTU limitbut only for large systems: they<suggested EPA promulgate a separatelimit of 1 NTU for small systems. Stillother commenlers favored the 0.5 NTUlimit but thought the rule should allowthe Slate to increase the limit if therewas evidence of effective removal ofCiardia cysts or Ciardia cyst-sizedparticles at higher turbidities.

In response to these comments. EPArequested comment on alternatives tothe proposed turbidity provisions In theMay 6,1988, notice of availability (53 FR16354)tMost commenlers responding tothis issue aupported these changes. As aresult, many have been included In thefinal rule. These changes are describedbelow.

The final rule allows the State to .reduce the monitoring frequency for „turbidity to one grab sample per day to/systems serving 500 or fewer people if •the Stale finds that the historicalperformance and operation of thesystem Indicates effective particulateremoval under the variety of conditionsexpected to occur in that system. EPAbelieves this provision for reducedmonitoring is appropriate because, forvery small systems, grab samplemonitoring every four hours of operationmay not be feasible (I.e., It laeconomically Infeasible to provide thedegree of operator attention necessaryto conduct such monitoring: likewise. Itis costly to Install and Impractical to .maintain automated turbiditymonitoring equipment). Al the reducedmonitoring frequency, the Mintperformance criteria would apply. Thus,for Instance. If two or more of Ihe 30samples taken In one moathexceed theturbidity limit, then less than 05 percentof Ihe samples would meet the turbidityperformance criterion, and the systemwould be In violation of a treatment 'technique requirement.

EPA believes thai II Is feasible formost systems using convenlionaltreatment or direct nitration to achievethe turbidity performance criterion ol 0.5NTU (see 52 FR 42200. 42205-42206).EPA believes It'is generally^necessaryfor systems using conventional

treatment or direct filtration to meet thisturbidity limit to. achieve at least 99.9percent removal and/or inactlvation ofCiardia cysts with filtration anddisinfection. EPA recognizes that manyexisting Filtered systems currently maynot be meeting the proposed turbiditylimit; however. EPA believes that mostof these systems can meet these limitsw i t h treatment modifications thatinvolve very low costs (see Table Vl-3).

EPA recognizes that it may bepossible for some systems that currently«re not meeting Ihe turbidityperformance criterion, depending uponraw water quality and other treatmentcharacteristics, to still achieve theoverall minimum (or better] removaland/or inactive lion of Ciardia cysta.Therefore. Ihe final rule allows a systemto operate at higher filtered turbidities,up to 1 NTU In at least 05 percent of themeasurements, If the Slate determine*that the system la achieving theminimum performance requirement of99.9 percent removal and/or inactive lionof Ciardia cysts at the higher turbiditylevel. Unlike the proposal the final ruledoes not require the system to actuallydemonstrate (e.g.. with pilot plant studyresults) it Is achieving the minimumperformance requirements at the higherturbidity level to be allowed to operateat this level. Instead, the Slate'sdetermination may be based upon ananalysis of existing design and operatingconditions (e.g., adequacy of treatmentprior to filtration, percent turbidityremoval across Ihe entire treatmenttrain, stringency of disinfection) and/orperformance relative to certain waterquality characteristics (e.g..microbiological analysis of the filteredwater, particle size counts in waterbefore and after filtration). The Slatemay wish to consider such factors assource water quality and system size indetermining the extent of analysisnecessary. The final Guidance Manualwill provide additional guidance to theStates for determining when a higherturbidity limit might be appropriate.

For any filtration technology, EPAbelieves thai filtered water turbiditiesshould generally be less than 1 NTU inorder to prevent Interference withdisinfection of viruses. Allowing anaverage turbidity of less lhan 1 NTU. assome commenters suggested, wouldallow systems to exceed 1 NTU a highpercentage of the time, during whichtime there might be interference withdisinfection. Therefore. EPA has set anupper limit for 'urbidi'y of 1 NTU in 05percent of Ihe teasurements, ratherlhan specifying an average. As in theproposal, exceptions to this limit areallowed for slow sand filtration, up to 5NTU. but at no time exceeding 5 NTU. if

the system demonstrates to the Slatethat there is no interference withdisinfection, because studiesdemonstrate that slow sand fillers canachieve greater lhan 99.9 percentremoval of Ciardia cysts by filtrationalone at turbidities exceeding 1 NTU(Bellamy et at.. 1905a. b).

The additional flexibility in Ihe finalrule will allow States to applyengineering judgment, as appropriate, todetermine what Information isnecessary for demonstrating adequateIrcnlment performance. EPA anticipate*that this added flexibil i ty will reducecosts, especially for small systems,while still ensuring that adequatetreatment Is in place.

IV. Description of the Final Rule

EPA believes that all surface watersand ground water under the directinfluence of surface water are at risk, ntleast to some degree, fromcontamination by Ciardia lamblia andother protozoa, viruses, and pathogenicbacteria and that public water systemsusing such source waters should provideminimum levels of treatment to ensureprotection from Illness caused by thesecontaminants. Therefore, this ruleapplies to all public water systems (bothcommunity and non-community) whichuse a surface water source or a groundwater source under the direct Influenceof surface water.

This rule defines "surface water" asall water open to the atmosphere andsubject lo surface runoff (e.g.. riven,lakes, streams, reservoirs,impoundments). This rule defines"ground water under the direct influenceof surface water" as:any waler beneath Iht surface of the aroundwllh (I) ilfnlflcint occurrence of ln»i>ct» orother microerfinlimi. algne. or Itrjr-dismeter pslhof em luch as Giardin lamblia.or (ii) significant and relatively rapid shifts Inwaler chiracterlstlcs such as turbidity,temperature, conductivity, or pH whichclosely correlate to climatologleal or surfacewater conditions. Direct influence must bedetermined for each Individual source Inaccordance wllh criteria eitabliihed by IheSlate. The Stale determination of directInfluence may be bvied on ilte-ipecificmeiiunmenli of water quality and/ordocumentation of well constructioncharaelerittlc* and geology wllh fieldevaluation.

The Slate is responsible fordetermining whether a system usesground water under the direct influenceof surface water and is. therefore,subject lo Ihe requirements of this rule.Determinations of whether a groundwater system Is under the directInfluence of surface water must be madewithin 5 years following the

27504 Fedaral togbter / Vol. 54. No. 124 / Thursday. June 29.1989 / Rales and Regulations

promulgation date of tits ruLt torcommunity water supptiea and wimtn 10years fullowiasj the nroae]§atioa date ofthis rule for non-camaaail)r watersystems. Procedures Ifaacsuy be needbr determining wbetherlhare is directinfluence by surface watex wilt beincluded in the final Guidance Manual.Sidles way choose to apply generalguidelines bused on sourcechamctvmiics to expedite thedeiermimdion far easily dbaeacteriiadsources, nod to apply more specificcriteria, including microbiologicalanalysis, for SAUTES more difficult tocharacterize, For systems which usemixed source water supplies (Laxground water not under the directinfluence of surface water end surfacewater), this rule applies only to thewater originating from the surface watersource.

A. Operator PentamelRequireatenttUnder ibe final rule, efl systems using

surface water or ground water under thedirect influence of eurfece water mustbe operated by personnel that meetqualifications specified by Ibe State. Asdescribed later. States must developoperator qualifications IT they do notalready have them and require thatsystems ba operated by p*i^mn^t whomeet these qualifications. Theappropriate criteria for determining if anoperator is quelifitid depend upon thetype and size of tha system. EPAencourages States which do not yethave operator license certificationprograms in effect to develop suchprograms.

D Treatment Requirement*

\. SummaryUnder this rule, nil community end

nun-cummunity public water systemsusing any surface water somes musttreat their surface water source(s] te>achieve at least 99.9 percent removalnnd/or inacttvation of Giardio iambtiacysts, and at least 99.99 percent removaland/or Inacti vation of viruses. A systemis deemed to be in compliance with this

requirement if it complies with th»treatment technique requirementsspecified in this rule; At a minimum, thetreatment required for any surface watermust include disinfection.

Thus, systems with verjrdean endprotected source waters that meet thesource wetsr quality criteria- (includinglow total colifonn 01 feuat coliformlevels and low turbidity levels, asspecified in the rule) and certain site-specific criteria (Including an affectivewatershed control ptegrem). arerequired to use only disinfection toachieve 90.9 percent and198.99 percentinacti vation of Giardia. Iambi fa cystsand viruses, respectively. If suchsystems can continually meet theapplicable CT values specified in therule (or. if a disinfectant other thanchlorine is used, other criteria specifiedby the State], the system fs consideredto be in compliance with the requiredremoval and/or inactivatfon-requirements for Giardia famblia endviruses without monitoring for theseorganisms. Systems which cannot meetthe source water quality criteria endsite-specific criteria of this rule arerequired to filter their water.

Systems required to fitter can use-avariety of treatment technologies tomeet the minimum 99.9 and 99.99percent performance levete. A systemwith filtration that achieves certainturbidity levels and1 meets specifieddisinfection requirements Is deemed tobe In compliance with theseperformance requirements.

For most source waters hi the United1

States, EPA considers conventionaltreatment (whten mcrades coagulation,flocculetion, sedimentation, rapidgranular filtration-, and disinfection) tobe the best technology for controllingmicrobiological contaminants becauseof the multiple barriers of protectionthat it provides. Conventional treatmenthas been demonstrated to achieve at.least 99.9 percent removal and/orinacri vation of Giardia lamblia cystsand 99.99 percent removal and/orinactivatiort of viruses under

appropriate design and operatingconditions (USEPA. 19B8bJ; H is thebenchmark against which watertreatment decisions, should be fudged-.Direct filtration (.which Includescoagulation}, slow sand filtration, and1

diatomaceous earth filtration, each withdisinfection, also have beendemonstrated to achieve at least99.9percent removal and/or inacti vation ofGiardia lambJia cysts and 99.99 percentremoval and/or iuactivstlon of viruses,under appropriate design and opetaJlngconditions (USEPA. IMObJ,

Under the final rule, a public wateasystem also may use. & CItralioatechnology other than lha four specifiedabove if it damanstcatus u> to*. State,using pilot plant challenge studies* atolhet appropriate, means, thai lh»fihrntioa technology, in combinationwith disinfection, achieves el least 99*9percent and>9ftJ9 percent removal awUor inactivation of Giardia lemblim eyetsand viruses, respectively. la addition*the State-may approve • larhnsjlnpdemonstrated to ba efiactiM al one sferfor use at another she if the sourcewafer quality conditions* CD the tMoastae»re similar.

hi determihmg the apprepriot*technology to be used, source waterquality, site-specific rectors (e.g;.available land location of the treatmentplant relative to the water source,wa.ite-dijpoiaf concerns), andreosreffectiveness need to be considered-Bigeneral, the level of treetment provided'should be commensurate with thepotential for pathogen contamination lathe source water. Table IV-1 providesguidelines for selecting filtrationtechnologyfles] to be used based onsource waJer quality. EPA recommendsconducting pilot plant ttudlat te hetpdulczmine the most appropriatenitration technology uad the optimumdesign conditions. More detailed"guidelines for determining theappropriate technology and designconditions will be included in. the DaalGuidance Manual

TABLE IV-1.—GENCAAUZIO CAPABILITY OF FILTRATION SYSTEMS TO ACCOMMODATE VARIOUS RAW WATER QuAtrrt COMomoNft

TrMtmcrt Mchngtogy

Ac. MOMS'OOuUfe*

TeliicoMcn*(H/100M) |OU)*

ConvoniioMi TIMMMM. <200M

(wiifinoi <n

<soo

Federal Register / Vol. 54. No. 124 /Thursday. |unc 20.1909 / Rules and Regulations 27505

TABLE rv-1.—GENERALIZED CAPABILITY OF FILTRATION SYSTEMS TO ACCOMMODATE VARIOUS RAW WATER QUALITY CONDITIONS—"•• ContJnuod

Treatment tochni

Stow Ssnd FMrtHon.

Mric art** I* ynirs.J trtis.

G«oerol conmtnts (1 «..vniuvt occasor.*!iy couW Iw

Tol*l colitcrmt<»MOOml]

<SOO<so

Ttrtx*-

(NTU|«

Coir.ICU|«

'5<S

2. Criteria for Determining If Filtration IsRequired

Under the final rule. H public watersystem using lurface water mn>t usefiltration unlcft it meets the followingcriteria:

Source Water Quality Criteria• CoHforma• TurbiditySite-specific Criteria• Disinfection• Watershed control• Oil-site Inspection• Absence of waterbome discuse

outbreaks• Total coliform maximum

contaminant level (MCL)• Total trihalomelhanes (TTHMs)

MCLThese criteria arc described in detail

below.(a) Sou/re Water Quality Criteria—

(1) Coliform limit*. To avoid filtration, asystem must meet one of the followingcriteria: (1) The fecal coliformconcentration In water prior todisinfection Is equal to or less than 20/100 ml In at least 90 percent of thesamples; or (2) the total coliformconcentration In water prior lodisinfection Is equal to or less than 100/100 ml in at least 80 percent of the•ampler If a system monitors for bothparameters, it may exceed the total •coliform limit, but not the fecal coliformlimit, and still avoid miration, while asystem that meals the total coliformlimit, but not the fecal coliform limitmust install nitration. Minimumsampling frequencies for differentsystem sizes are as follows:

Poputatkxi «*d

. SM>SOI W 3 3003.301 to 10.00010.001 IOZ5.000

8»mpKn/

1 Miitl b* ukin en Mptrit* d«r»

This sampling must include onemeasurement on every day during which

I lie turbidity exceeds 1 NTU (unless theStale determines that the system, forlogistical reasons outside the system'scontrol, cannot have the sampleanalyzed within 30 hours of collection).This sample counts towards the totalnumber that must be taken each week.

The coliform limits are an ongoingrequirement; at the end of each month,the system must evaluate the datacollected for the preceding six months(he system served water to-the publicimd determine If this source waterquality condition Is still bring met. If thecriterion has not been met, the systemmust install filtration.

(2) Turbidity limit*. To avoidfiltration, the turbidity of the water priorto disinfection cannot exceed 5 NTU. onnn ongoing bnsls. based on grab samplescollected every four hours (or morefrequently) that the system Is inoperation. A system may substitutecontinuous turbidity monitoring for grabsample monitoring if it validates suchmeasurements for accuracy with grabsample measurements on • regularbasis, as specified by the State. If apublic water system uses continuousmonitoring, it must use turbidity valuesrecorded every four hours (or someshorter regular time Interval) todetermine whether it meets the turbiditylimit for raw water. A systemoccasionally may exceed the S NTUlimit and still avoid filtration as long as(a) the Stale determines that each eventoccurred because of unusual orunpredictable circumstances and (b) asa result of this event, there have notbeen more than two such events in Ikepast twelve months the system servedwater to the public or more than fivesuch events in the past 120 months Itiesystem served water to the public. An"event" is defined as a series ofconsecutive days in which at least oneturbidity measurement each c*->yexceeds 5 NTU.

It is important to nole that everyevent, i.e.. rxceedanw of the S NTUlimit, regardless of whether the systemmust filler as a consequence, constitutesa violnlion of a treatment technique

requirement. For cxjmple. If theturbidity exceeded 5 NTU in ut lo.-isf im;measurement eiicli tiny for lliri.Tconfteinitive duys. this would miis'Siu!"one event nnd one treatment iRchniqui:violation. If (his was the third event inthe past 12 months the system srrrviKlwater lo the public, or the sixth nvnnt inthe past 120 months tho system h.idserved wnter to the public, the systemalso would be required to instnllfiltration. In all cases, the system mustinform thn State when the turbidityexceeds 5WTU as soon ns poitsiblft. lintno later than the end of the nextbusiness day.

(b) Site-Specific Criteria—-(1)Disinfection requirement?. To iivuidfiltrsllon, this rule requires that a *y*irmpractice disinfection nnd hnvo eilht-r (>•)redundant disinfection capability,including an auxiliary power supplywith automatic start-up and aliirm. Inensure that continuous disinfection <sprovided; or (b) automatic shut-oft nfdelivery of water to the distributionsys'em whenever the disinfectantresidual Is less than 0.2 mg/l in Ihnwater. A system that fails to meet eitherof these requirements must installfiltration. The option of automatic shut-off is not permitted If the Slatedetermines that this action could CJIIISPan unrcasonnble risk to hrulth (e.g..automatic shut-off is not appropriate if itresults in negative pressures within thedistribution system or inadequate WHtrrsupplies for fire protection).

(i) Maintenance of a Hisinfcclnnlmsidual at the point of entry. To avoid

' filtration, the disinfectant residual inwater entering the distribution systemcannot be IMS than 0.2 mg/l for morethan four hour*, with one exceptionnoti'd below. Systems serving morw ihiin3,300 personri muM monitorcontinuously. If there is a failure in ihrcontinuous monitoring equipment. Ihrsystem muy substitute grnb snmplingevery four hours for up lo live workingdays following the failure of theequipment. Systems serving 3..100 orfeivrr people in;iy monitor conlinuniiNly

27506 Federal Register / Vol. 54. No. 124 / Thursday. June 29,1989 / Rules and Regulations

or lake grab samples at the^ frequencies(iicsciibrd below:

S/iicm «z« by population

'•00*>t) in 1 OOO

1 001 10 2 500 -2 SOt to 3300

SwnplM/<Uy '

1234

cannot M Uken at m« Mm* hnw. Th»umplmg rvltrv*!* «• *ut<(UC1 to SUM l*vt«w andapproval

If at any time the residual disinfectantconcentration fu l l s below 02 mg/1 in •system using grab sample monitoring,ihc system must continue to take a grabsample every four hourv until theri-iiiluiil clisinfectunl concentration isrqu;il to or greater than 0.2 mg/1. Fur all.systems, if the residual conccntrulion isoot restored to ul least 0.2 mg/1 withinfour hours after • value of less than 0.2(ng/1 is observed, the system is inviolation of a treatment techniquerequirement, and must install filtration.However, if the Stale finds that thenxcccdance was caused by an unusualiiml unpredictable circumstance, theShite nuy choose not to requirefiltration. EPA expects the Stales to useth is provision sparingly: it is intended toencompass catastrophic events, notinfrequent hirgc storm events. In•ulilition. any lime the residualconcentration fulls below 02 mg/1, thesystem must notify the Slate.Notification must occur as soon aspossible, but no later than by the end ofIhc next business day. The system alsomusl notify the State by the end of thenext business day whether or not (heresidual was reslorsd within four hours.

(ii) Minimum percent iiiactivolionrequirements. To avoid filtration, asystem must maintain disinfectionopi.Tulionjl conditions which inactivateii'i.'J percent of Giardiu lamblia cysts;md 99.99 percent of viruses. To makeiliis demonstration, the system mustdetermine disinfectant resldual(s),disinfectant contact time(s), pH. andwutcr temperature, and use these duUIn calculate whether it Is sneellng theminimum lota) percent inactivationre(|iiiremcnti in the rule. (The CT value*necessary to achieve 99.9 percentiuiiciivalion of Giardiu lamblia cystsmid 9U.99 percent inaclivalion of virusesliy various disinfectants and underv.irious conditions are specified in therule.) A system Is deemed in compliancewild the inaclivution requirements if the( V I ' vuhtu(s) calculated for itsdisinfection conditiuns meet (or exceed)tin.- icleviint CT vulue specified in Iho •rule. Tlic system must muke thistlcliTininiilion each day Ihul It is

'il. l ivcr i i iR waier to its customers. For

disinfectants other than chlorine, nsystem muy demonstrate, through use ofa Stale-approved protocol foron-silodisinfection challenge studies or otherinformation satisfactory to the Slate,that disinfection conditions other thanthose specified in the rule are adequatefur meeting the minimum levels ofinaclivulion.

For the purpose of calculating CTvalues, disinfection contact time (inminutes) is the lime it takes the water,during peak hourly flow, to movebetween the point of disinfectantapplication (or the previous point ofmeasurement) to a point before or at thepoint where the residual disinfectantconccntrulion (in mg/1) is measured(which in turn must be before or at thofirst customer). The point of disinfectantapplication is defined as the point wherethe disinfectant Is applied and waterdownstream of that point I* not subjectto recontamination by surface waterrunoff. Contact time In pipelines musl becalculated based on "plug flow" (i.e.,where all water moves homogeneouslyin time between two points) by dividingthe internal volume of the pipeline bythe peak hourly flow rate through thatpipeline. Contact time within mixingbasins and storage reservoirs musl bodetermined by tracer studies or anequivalent demonstration.

Under this rule, systems with only onepoint of disinfectant application maymeasure "C" at any number of pointswithin the treatment train, determineeach corresponding "T" and therebycalculate the CTs for each sequence todetermine the percent InacUrationachieved. The total InacUvation ratioAchieved is the sum of ell the fractionalinactivations calculated for each pointwhere disinfectant residual wasmeasured. To determine the totalInaclivatlon ratio achieved using thismethod, the system must calculate theCT for each point where "C" was 'measured (CTcalc) and compare thiswith the CT.*.* value (the CT valuerequired to achieve 99.9 percentinacJJvation of Giardia cysts) given inthe rule for the particular conditions(pM, temperature, and residualdisinfectant concentration) at that point.Specifically, the system musl divide—-each calculated CT value by Itacorresponding CTW.t value in the rule todetermine the inaclivation ratio for eachpoint where "C" was measured. If thesum of the inficlivnlion rulios, or

CTculcT^ .. CIV..

is equal to or greater than 1.0 (I.e.. thosum of all the sequences for which CTwns calculated I to fore or at the firstcustomer provides 99.9 percent or moreinactivalion of Giardia lamblia cysts),the system is meeting the disinfectionperformance requirement. In otherwords. If: C.T./CTV • + C,Tt/CT*.. +CaTi/CTM* + . . . + C.T./CT.... >1.0(where CT.,.. Is specified In the rule foreach combination of C«. d, C>.. . . C.;temperature; and pH), the system Ismeeting the disinfection performancerequirement.

Systems need only calculate one CT(CTcalc) each day for a point before orat the first customer. Alternatively,systems have the option of calculatingmultiple CTs aflor the point ofdisinfectant application but before or atthe first customer to determine theinactivation ratio. If one CT iscalculated (CTcalc) and this exceeds theapplicable CTttj. the system is meetingthe disinfection performancerequirement; this may be all that Isnecessary for systems with very lowoxidant demand In the water or systemswhere it is obvious they will achieve atleast 99.9 percent inactivation.

For systems with multiple points ofdisinfectant application (e.g., ozonefollowed by chlorine, or chlorine appliedat two different points in the treatmenttrain), the inactivation ratio of eachdisinfectant sequence before or at thefirst customer must be used to determinethe total inoctivallon ratio. Thedisinfectant residual of each disinfectionsequence and the corresponding contacttime must be determined at some pointprior to the subsequent disinfectionapplication point(s) to determine theinuctivalion ratio for that sequence, andwhether the total Inactivation ratio of1.0 or greater Is achieved. For example,if the first disinfection sequenceprovided un inactivation ratio of % (or99 percent inactivation) end the seconddisinfection sequence provided aninuciivalion ratio of Vi (or 90 percentinuctivalion), the total inactlvallon ratiowould equal 1.0 (fc + Vfc - 1). The totalpercent Inactivation could also bedetermined as follows:

100lnuclivulion«100- —

whury !__:: XJy-X (CIV.)

If (he system fails to achieve ut Ion*)99.H pnrcitnl inactivution (i.e., Ihc

Federal Register / Vol. M. No. 1Z4 / Thursday. )uno 29.1909 / Rules nnd Regulations 27.107

Inaclivatton ratio It less than 1.0) anytwo or more days in one moritti. thesystem It in violation of • treatmenttechnique requirement for that month. Ifthis violation occurs during • secondmonth In any 12 consecutive months thesystem serves water (o the public, thesystem must install nitration, unless theSinle determines that at least one ofthese violations was en used bycircumstances that were unusual andunpredictable. A third violation In 12months, regardless of the CMUSC. triggersnitration.

Guidance for determining the percentinsr.ttvstion of Ciardia cysts and virusesunder different conditions will beprovided in the final Guidance Manual.

(iii) Maintcxnncf of a disinfmiuntmitlaal in the distribution tystcm. Toavoid filtration, the disinfectant residualIn the distribution system cannot beundnlectiible in more than five percentof the samples in a month, for any twoconscr.utive months that the systemserves water to the public. Systems maymeasure HPC instead of disinfectantresiduaj. Sites with UPC concentrationsof lens lhan or equal to 500/ml areconsidered equivalent to sites withdetectable residuals for the purpose otdetermining compliance. Public watersystems must monitor for the presenceof • disinfectant residual (or JfPC levels)at the same frequency and locations astolnl coliform measurements takenpursuant to the total coliform refutationpublished elsewhere in today's FederalRegister. However, if the Stoledetermines, based on site-specificconsiderations, that a system hns nomr.ins for having a sample transportednnd analyzed for HPC by a certifiedlaboratory within the requisite lime andtemperature conditions (Method 907.APHA. 1985). but that the system I*providing adequnle disinfection In thedistribution system, this requirementdors not apply to that system.

For systems which use both surfaceand ground ws'er source*, the Stnfi?mny allow the system to Ifiktdisinfectant reslclunl or HPC samples «tpoint* other Hum the tnl.tl coliformsampling locutions If the Mutedetermine* thai surh points am momrepresentative of treated (dl»lnfer.l««l)water quality within the distributionsystem.

If» syslnm fiiils In maintain ndetectable disinfectant residual or imI (PC In vel of less lhan or eqtml to MO/ml in more than 5 percent of the samplesduring a month, for any two consecutivemonths the system serves wnlcr In thnpuhlic. the synlcm is in violation of Atreatment technique requirement. InHddiiioo. thin system must Installfi l trat ion unless thr Sl.ilir dn

Ihnt the violation was not due to adeficiency In treatment of the sourcewater (e.g., the violation was duff to adeficiency in the distribution system,such as cross-connection contaminationor failure in the pipeline).

(2) Watershed control requirements.To avoid filtration, systems mustestablish and maintain an effectivewatershed contrv program to minimizethe potential contamination by Ciardialamblia cysts am! viruses In the sourcewHier.

The State must determine whether thewatershed control program is adequateto limit potential contamination byGiardia lambl'a cysts and viruses. Inmaking this determination, the Staltmust consider the comprehensiveness ofthe watershed review; the effectivenessof the system's program to monitor andcontrol activities occuiriiiK in thewHleishud that could have an adverseeffect on water quality, and the extent towhich the system has maximized tandownership and/or control of land usewithin the watershed. At a minimum,the watershed control program must (1)Characterize the watershed hydrologyand (and ownership; (2) identifywntcrshed characteristics and activitieswhich may have an adverse effect onsource water quality; and (3) monitor theoccurrence of activities which may havean adverse effect on source waterquality. The public water system mustdemonstrate through ownership orwrit ten agreements with landowners inthe watershed, or a combination of both.that it controls all human activitieswhich may have an adverse effect onthe microbiological quality of the sourcewater. The system must submit anannual report to the Slate that identifiesany special concerns about thewatershed and how they aio beinghandled: describes activities in thewatershed that affect water quality; andprojects what adverse activities oreexpected to occur in the future anddescribes how the public water systemintends to address them. For sy stemsusing a ground witter source under I hodirect influence of surface water, anapproved wellhend prnlccH'Hi prngrintdeveloped under section 1< *8 of the SafeDrinking Water Act mny be used, if theSlHte deems it appropriate, to mrclIhiise requirements. Guidance fordeveloping and maintaining an effectivewatershed control program will beincluded in the final Guidance Miinunl.

(3] On-fit* inspn-timi n»i/iiim»n'nfs.To avoid filtration, a system must havean annual on-sile inspection conductedhy the State, or hy n party approved Uythe Stale, which dcmonslin'es Ilia! thesvslcm is m;iintiiintng an adequatewatershed roiifrul program and n-liaMe

disinfection treatment. The purpn«e ofthe on-silb Inspection is to identify allmicrobiological health hazards nndassess their present and futureimportance. The on-sile inspection mnoinclude;

(a) A review of the effectiveness ofthe watershed control program:

(b) A review of the physical conditionof the source intake and how well it isprotected;

(rl A review of ihc system's 'equipment m 'inlcnance progrom toensure th.v :*pr» Is low probability forfailure of th> d infection process;

(d) An ins^c'.ion of the disinfectionequipment f • physical deterioration;

(c) A reM'-w of operating procedures;(OArevir" of data records to insure

that all required tests are bringconducted and results recorded, andthai disinfection is effectively pi.ii.lii.nl.and

Ig] Identification of any improvr-noni*which arc needed In the equipment,system maintenance and operation, ordata collection.

The on-site inspection must beconducted by a competent i iiudii.il(s)such as a sanitary or civil r-pjnror.sanitarian, or technician who hasexperience in and knowledge about theoperation and maintcnaiK e of a wadrrsystem, and who has a soundunderstanding of public healthprinciples and walerlximc diseases. Areport of the on-sile inspectionsummarizing all findings must be-prepared every year. The Slate willreview the report and dr.lermincwhether the system is maintaining noadequate watershed control programand reliable disinfection treatment. K.l'.Awill include detailed siigRcstions foiconducting an on-site inspection umlinterpreting the results in the finalGuidance Manual.

(4) Ahsemn of \\-ntnrh<:riic ilimiispfliithrttikx. To avoid filtnttion. a sj xti-inrantiot hnvn Ivren identified as it *niin:i«of walerhnrnr disease nulltrrnk. or ff Ithu* l>Rcn %n iilonlified. the system musthave been modi find sufficiently toprevent another Mich occurrence, uslieterminrd hy the Slate. An unMt-ntnlsystem riiAt h.is a waterlxirne disruseoutbreak is in violation of a treatmenttechnique reqiiiremenl which poses anacute risk lo health. A "w;il«rbonw«disease outbreak" is defined as nsignificant <n:nirrenre of acuteinfectious illncrs that the Stale or l«x .dher'th flgenry him dnlermlneH l-i hoepi.lemiologiailly associalwl wi th Ihi-irprslion of water from a publir watersystem that if. deficient in treatment.

|5) Cuniiilirint •• with ltn> luli-.l<-^ii- '"innitt\intnnt i-<>n!,in>itinnt /:•> »•/ fMCI I To

275M Federal Register / Vol. 54. No. 124 / Thursday^ |une 29.1989 / Rulm and Regulations

avoid filtration. a system must complyiviih the MCI. for total culifumu.published elsewhere in today's FederalRegister, al It-us 1 11 out of the previousU months the system served water tothe public on un ongoing basis. unlessthe Slute determines that failure to meetthis requirement wds not caused by adeficiency in treatment of the sourcewitter. If the Stale nuikus such adetermination, the system is notrequired to install nitration. The totalcol i form rule requires systems usingsurface water or ground water under theinfluence of surface water which do notfiller to collect a sample at or near thefirst customer each day that theturbidity level exceeds I NTU within 24hours of learning of the result and toanalyze the sample for the presence oftotal coliforms. (If the State determinesthat it is not possible for the system toluu-c such a sample analyzed within 24hours, this time limit may be extendedon a case-by-case basis.) This samplemay be used to fulfill the routinecompliance monitoring requirements ofthe totul coliform rule. The results of theAdditional sample must be included indetermining whether the system is incompliance with the monthly MCL fortotal coliforms.

(6) Compliance with the totaltrihah)inelhone MCL To ovoidfiltration, a system must comply with(he total trihulomcthane (TTMM)regulation (40 CFR 141.12 and 141.30).An unfil It-red system that violates theTTIIM regulation must install filtration.Currently, this requirement only appliestu systems serving more than 10,000people. When new regulations fordisinfection by-products arepromulgated, EPA expects they will.ipply to smaller systems as well nsiliusc larger systems. At thut lime, thoseMii.illcr systems would be required lot. <>mply with Iliusc it?qiiin:mi!filii lo avoidfil irution.

3 Criteria for Determining iis Adequate for Filtered Systems

Systems which fail lo meet one ormore of the above criteria for avoidingduration must install nitration. Thissection describes the performancecriteria for these systems which mustinstall fi l tration, as well as systems thaialready are filtering thutr water

(a) Disinfection requirements. Underthis fin.il rule, the requirements fori iu i in ia in ing a disinfvctiinf residual althe entry point to the distribution systemund in the distribution system describediibove fur unfilicred systems also applyIn filtered systems. The Slate musttli.-li.-rmine (lie level of disinfectionriniuired for each system to ensure (huttin; tolul treatment |iiocei>s'(i *

filtration and disinfection) achieves atleast a 99.9 percent (3-log) and OU.UUpercent (4-log) removal and/orinactive lion of Ciardia lamblia cystsand viruses, respectively. The finalGuidance Manual will recommenddifferent levels of disinfection as afunction of different treatmenttechnologies and source water qualities.

(b) Turbidity monitoringrequirements. Under this rule, systemsserving more than 500 people which useconventional treatment, direct filtration,or diutomaceous earth filtration mustmonitor the turbidity of representativefiltered water by grab sample every fourhours (or more frequently) that (hesystem is in operation. A system maysubstitute continuous turbiditymonitoring for grab sampling if itvalidates such measurements foraccuracy with grab samplemeasurements on a regular basis, asspecified by the Slate. If a syslem usescontinuous monitoring, it must use theturbidity value for every four-hourinterval (or some shorter regular timeinterval] lo determine compliance withthe turbidity performance criterion.

For systems using slow sand filtrationor technologies other than conventionaltreatment, direct nitration, ordiatomaceous earth filtration (such ascartridge filtration), the State mayreduce the sampling frequency forturbidlly to one sample per day if theSlate determines that less frequentmonitoring is sufficient to Indicateeffective filtration performance.

For systems serving 500 or fewerpeople, (he Slate may reduce thesampling frequency to ones per day.regurdtess of the type of nitrationtreatment used if the State determinesthai less frequent monitoring issufficionl to indicate effective filtrationperformance.

(t) Turbidity (iitrfunnance criteria—(l) Conventional treatmtnt or directfiltration. For systems usingconventional treatment or directfiltration, the final rule requires that thefiltered water turbidity level be lessthan or equal to 0.5 NTU in-05 percent ofthe measurements taken every month.anJ at no lime exceed 5 NTU. Thesystem must inform the Slate when theturbidit} exceeds S NTU as soon aspossible, but not later than the cnd-ofthe next business day.

The Stale may allow any system analternate turbidity limit, up to 1 NTU in95 percent of the meassuremenls. if theSlate determines thai (he system isuchieving the minimum overallpurformiiiice requirement of W.9 percentremovMt und/or inactivation of Ciurdiu

liti cysts al the higher tu rb id i ty •-

level. Such a determination may bubased upon an analysis of existingdesign and operating conditions (e.g..adequacy of treatment prior to filtration,percent turbidity removal across theentire treatment train, and level ofdisinfection), and/or filtrationeffectiveness relative to certain waterquality measurements (e.g.,microbiological analysis of the Tilleredwater, particle size counting before andafter the filter). Under (his provision, theSlate may consider such factors assource water quality, extent oftreatment, and system size to determinethe analysis necessary to justify thehigher turbidity limit. In the finalGuidance Manual. EPA will provideadditional information for determiningwhen it may be appropriate to allowhigher turbidity performance criteria.

All systems are expected to optimizetheir treatment so as to achievi thelowest turbidities feasible at all times.This will promote optimal removal ofCiardio lomblia cysts and otherpathogens, and provide optimalconditions for disinfection.

(2) Slow tandfiltration. For sysltmsusing slow sand filtration, the final rulerequires lhat the Tillered water turbiditybe 1 NTU or less in 95 percent of themeasurements token each month and atno time exceed 5 NTU. However, theSlate may allow a turbidity valuegreater than 1 NTU. but below 5 NTU. lit95 percent of the measurements If theState determines there is no significant .interference with disinfection at thehigher turbidity level. The system mustinform the Stale when the turbidityexceeds 5 NTU as soon as possible, butnot later than the end of the nextbusiness day.

(3) Diatomoceout earth filtration. Forsystems using diatomaceous earthfiltration, the filtered water turbiditymust be loss than or equal lo 1 NTU Innl least 95 percent of the measurementstaken each month. At no time may the •turbidity exceed 5 NTU. The syslemmust inform the Stale when the turbidityexceeds 5 NTU as soon as possible, butout later than the end of the nextbusiness day.

(4) Other filtration technologic*. Apublic water system may use • filtrationtechnology other than one describedabove if it demonstrates to the State,using pilot planl studies, conducted on-site or at another site with similarsource conditions, that the alternativefiltration technology, together withdisinfection, consistently achieves 99.9percent removal and/oi inactivation ofCitirdio lawbliu cysts and 99.66 percentremoval und/or inuctivation of viruses.The system must meet (he same

Federal Register / Vol. 54, No. 124 / Thursday. June 29,1989 / Rules and Regulations 27'509

turbidity limlti prescribed for slow und •nitration. . .C. Reporting Requirement*

Reporting requirements for all publicwater systems which UK • surfacewater source or a ground water source 'under the Influence of surface water arespecified In 1141.75 of the final rule.Theiic reports are designed to documentcompliance with the treatment andmonitoring requirements In || 141.71,1*1.72.141.73. and 141.74 (describedabove). Separate requirement* arespecified for systems which do not usefiltration and systems which do usefiltration.

IJUnfillcrcd SystemsSystems which do not UM filtration

are required to report to the Stale on amonthly basis whether they are meetingthe treatment and monitoringrequirements for avoiding filtration, foreach month they serve water to thepublic. The report must include asummary of the results of source watermonitoring for tola] or fecal coliforms (ifthe system monitors for both, only fecalcollforms must be reported) andturbidity, to demonstrate compliancewith 1141.71(a). The specific Items to bereported are listed in | I41.75(a)(l).

Each system that does not use •filtration must report disinfection v

conditions monthly to demonstrate that:(1) It met the 99.9 percent Giardialomblia cyst and 99.99 percent virusInaclivatlon performance criteria; (2)(here was not less then 0.2 mg/ldisinfectant residual in the watersupplied to the distribution system formore (han four hours; (3) II met therequirement to have a detectabledisinfectant residual or an HPC levelless than or equal to 500/ml. The .specific Information about disinfectionto be reported is listed in 1141.7S(a)(2).After ajystem reports this Informationfor one year, the Slate may waive moatof the disinfection reportingrequirements.

Other reporting rcqutreanonla for .systems which do not provide filtrationInclude;

• An annual report which summarizesthe system's compliance with allwatershed control program requirementsspecified In 11<; 71(bj(2).

• An nnnuul IT port summarizingresults of the on-»lte Inspection whichevaluated the effectiveness of thewatershed control program and thereliability of the disinfection process,unless the on-site inspection wasconducted by the Stale. If the InspectionIs conducted by the Slale.lhe State mustprovide a copy of its report to the publicwater system.

• Reports of waterborne diseaseoutbreaks, turbidity measurements over5 Nil), and failure to maintain adisinfectant residual of 0.2 mg/l at thepoint of entry to the distribution systemfor more than 4 hours.

2. Filtered SystemsPublic water systems which use

filtration must report to the Slate on amonthly bnsis information regardingfiltered water turbidity, disinfectantresidual concentration in the watercoloring the distribution system, anddisinfectant residual concentrationsand/or HPC measurements In thedistribution system. Turbidity reportingrequirements vary depending upon thefiltration technology used. Reportingrequirements pertaining to disinfectionrequirements at the point of entry to thedistribution system and within thedistribution system are the same forfiltered and unfillcred systems. Thespecific requirements are sot out In114l.75(b).

Systems must also report waterbornedisease outbreaks, turbiditymeasurements over S MTU, and failureto mainlain a disinfectant residual of 0.2mg/l At the point of entry to thedistribution system for more than 4hours.

D. Compliance

1. Compliance Transition with CurrentTurbidity Requirements

The existing (interim) NPDWR forturbidity, including the MCL in 1141.13and the monitoring requirement* in .i 141.22 will continue in effect forunfilterod systems using a surface watersource until 90 months afterpromulgation of this rule. However,there Is an exception to (hisrequirement. If the Slate determines thata system must filter (in writing. Inoccordance with sectionl41J(b)(7)(Cpl)) earlier than 30 monthsfrom the promulgation date, that systemrmtet continue to comply with theinterim turbidity rule until 4fl monthsfrom promulgation or until filtration Isinstalled, whichever is later. Thus, If thetyslcm Installs filtration before 48months from promulgation, it wouldcomply with the Interim turbidityrequirements until 40 months from,-promu1|{ulion. and the turbidityrequirements for filtered systemsprumulgnled today in 1141.73 andf 14l.74(c) would apply after that dale.

It Is Important to note that, for awhile,unfiltered systems will be subject toboth the interim turbidity MCL andmonitoring requirements, and theturbidity monitoring requirements forunfiltered systems promulgated in

| 141.74(l»)l2). at the same time. This i*appropriate because the monitoringrequired under 1141.22 is different frontthat required under 1141.74(b)(2):1141.22. requires that samples be l/<Vi-ndally at a representative entry point tothe distribution system, while114l.74(b)(2) requires that sample* betaken every four hours prior to the pointof disinfectant application. Thus. Ihrformer Is a mrnsure of finished wntrr.while the Inttcr is s measure of sourcewnlcr quality.

The interim requirements for turbidityunder IS 141.13 and 141.22 will apply tofiltered systems using a surface watrrsource until 46 months after thepromulgation of this rule. Beginning 4ilmonths after the promulgntinn of thinrule, the turbidity performance criteriafor filtered systems In 1141.73 nnd Ihi;monitoring requirements undrrI I41.74(c), both promulgated todny. willapply.

2. Systems Using a Surface WntnrSource (Not Including Systems Using nGround Water Source Under the DirectInfluence of Surface Water)

As required by SDWA. within 18months following the promulgation ofthis rule. Slates must promulgate anyregulations necessary to Implement thisrule. Under section 1413. these rulesmust be at least as stringent as thoserequired by EPA. Within 30 monthsfollowing promulgation of this rule, euchSlate must determine which systems nrnrequired to Install filtration. If filtrationit required, it must be Installed within 4I»months following the promulgation ofthis ruin. If it is not feasible for a systemto instiill filtration within this lime, thr>State mny allow for a longer periodunder the exemption provisions ofsection 1418. as discussed in SectionIV.G. below. Procedures for StateImplementation of today's rule appear inSection V, below.

As described above, today's rulespecifies (a) conditions systems mustmcfit to avoid filtration (nnd othercriteria for unfiltered systems), and (l>)requirements that apply to filteredsystems. Rcgurdless of whether the

> State complies with the statutoryschedule for adapting the criteria andapplying Ihnm to determine whichsystems must Inslnll filtration, enchsystem using a surface wolcr sourcemust comply with one or the other, i.e.,either the criteria 'or avo'ding filtrationand other icquire tents for unfilteredsystems or the requirements for. filteredsystems, by the relevant statutorydeadline. Thus, beginning 30 monthsafter promulgation of this rule, therequirements for avoiding filtration

Federal Register / Vol. 54. No. 1^4 / Thursday, June 29,1989 / Rules and Regulations

.SJIC..-I.L-J in { ui.71 ja| and (b) end (hen (jiii/pinLr.u of f H1.?l|c) and$ 141.7^a) go into effect unless the SlMleuuT.iJy )u. determined that filtration isif. j lircd; d system thai fail* lo meet anyoni: uf iln* ir: i i ru fur avoiding filtrationin $ 141.71 )d) and (l)| must installf i l i iai ioi i <ui<i comply with all theic<|.iirtrmfn!s for filicrvd systems ( theyi.-neral requirements in § 141.73 and thedisinfection requirements in i 141.72(b)]within 40 months of prutnulpHlion.Likewise, beginning 30 monihs lifterpromulgation, if • system fail* lo meetany one of the criteria for avoidingfiltration, even if Ihe system wasmeeting nil the criteria up to that point,it niust install filtration and comply withthe requirements for filtered systemswithin 16 months of the failure. In eitherca;.e. whenever a Stale determines thatfiltration is required, it may specifyinterim requirements fur the period priorin msiiilldtion of filtration treatment.

To obtain the information necessaryto determine whether an unfillercdsystem is meeting the criteria furin Aiding filtration in f 141.71 (u) and (b).the rule includes monitoring andreporting requirements for unfilieredsystems (see If 141.74(b) and 141.7S(a).respectively). These requirements go Vinto effect IB monihs after promulgationof this rule, unless the State has alreadydetermined that filtration is required.

In reviewing these data, it Is up to theSuite lo determine how it will weigh thedatd gulhered during the first 30 monthsfollowing promulgation in decidingwliulher filtruliun is required. Thus, forniit.incL', a system niuy nut meet thespecified CT requirements for the firstfuur monihs of monitoring (i.e., months10-23). upgrade its disinfection practiceund then begin meeting the CT values insubsequent monihs. In this case, theSidle could conclude that the systemwould be nble lo meet this criterion foravoiding filtration, even though thesystem did not meet thr criterion 11 outuf Ihe 12 previous months, as specifiedin i 141.7i(b)f I). In other words, the timeperiods specified In the criteria forj i v u i J i n g filtration (e.g., six months fortoi.il coliforms, one year and ten yearsfur lurbidily. one year fur CTrequirements) do not begin unti l 30months from the dale of uromulgulion(unless the Siiite specifies un earliertli.ic).

All systems with fil lrutioti In pl.icemust meet llit treatment techniquerequirements specified in 1141.73( f i i i i u t i o n criteria) and { 141.72(b)(dlsirifectiui criteria), and themonitoring und reporting requirements

e.lied in Si l«1.7-l[t) und H1.75|b).

respectively, beginning 48 months aflnrpromulgation.

The above compliance dutes arediflercnt from what were proposed.Under Ihe proposed rule, all monitoring,reporting, and treatment techniquerequirements for unfiltored and filteredsystems would have gone into effectbeginning 48 months after promulgationof this rule. EPA believes that thisschedule would not have beenconsistent with the intent of the SOW A.First, El'A believes that the statutoryschedule (i.e., Stales make filtrationdecisions within 30 months and systemsinstall filtration IB monihs later)contemplates thai systems which meetthe crileria for avoiding filtration willmeet them beginning no later than 30months from promulgation, sine* this Uthe date by which aII filtration decisionsare to be made. Accordingly, EPAchanged the compliance dale in the rule.Second. It is clear that Stales will needmonitoring information to determinewhether systems are meeting the crileriafor avoiding filtration. Therefore, thefinal rule requires unfiltered systems lobegin monitoring 18 months frompromulgation (unless the State hasalready determined that filtration isrequired).

3. Systems Using a Ground WaterSource Under the Direct Influence ofSurface Water

As explained in the section on SlatoImplementation, below, (he State'sprogram revisions to adopt this final rulemust include procedures fordetermining, for each system In the Stoleserved by a ground water source,whether (hat source Is under Ihe directinfluence of surface water. Within fiveand ten years following thepromulgation of (hit rule (I.e.. byjune 29.1994 and June 29.1999 sacb Stats mu»tdetermine which community and non-community public water sy»tems, : ,respectively, use ground water which isunder the direct influence of surfacewater. EPA recommends that thesedeterminations b* made in conjunctionwith related activities required by otherregulations (e.g., sanitary surveyspursuant lo Ihe final coliform rule,vulnerability assessments pursuant lo(lie volatile orgunic chemicals rule, •assessment requirements in Iheforthcoming disinfection rule for groundwulcr systems). In addition, section 1428of the Safe Drinking Water Act requiredStales lo develop wellhead protectionprograms for ground-water supply wells.EPA-approved wellhead protectionprograms may contain methods andcriteria for determining zones ofcontribution, assessments of potentialcontHmination. and management of

sources of contamination. Theseprogrumi may be used as a partial basisfor determining (a) whether a system isunder the direct influence of surfacewater and (b) if direct influence exists,whether current watershed controls areadequate lo meet Ihe watershed controlrequirement for avoiding filtration({ 141.71(b)(2)). Guidelines fordeveloping and implementing a Slatewellhead protection program an foundin "Guidelines for Applicants for SlateWellhead Protection ProgramAssistance Funds under the SafeDrinking Water Act" (U.S. EPA, 1987d).

A system using a ground water sourceunder the influence of surface water thatdoes not have filtration lo place mustbegin monitoring and reporting inaccordance with II 141.74(b) and141.75(8), respectively, to determinewhether it meets Ihe crileria foravoiding filtration in 1141.71 (a) and (b)beginning 18 months after promulgationor six monihs after the Slate determinesthat the ground water source ia underthe influence of surface water,whichever is later. Within 18 monthsfollowing the determination thai •system ia under the direct influence ofsurface water, the State must determine,using the same criteria that apply tosystems using a surface water source, .whether Ihe system mual providefiltration treatment. (The 18-monthperiod was derived by adding the aixmonths until monitoring begins to the 12months SDWA provides States to makethe filtration decision for systems usinga surface water source.) Beginning 30monihs after promulgation of this rule,or IB monihs after the determinationthui a system is under lha directinfluence of surface water, whichever Ulater, the crileria for avoiding filtrationin 1141.71 (a) and (b) and therequirements for unfiltered systems ini 141.7l(c) and 1141.72(a) go into effectunless the Slate has determined thatfiltration is required. Thus, a systemusing a ground water source under theinfluence of surface water that fails tomeet any one of the crileria for avoidingfiltration after the relevant date mustinstall filtration and comply with all ofthe requirements for filtered systems(the general requirements in f 141.73und Ihe disinfection requirements ini 141.72(b)) 48 monihs afterpromulgation of this rule, or wilhin IBmonths of Ihe failure lo meet the crileriafor iM'olJir, fillruiion, whichever islate.. As v..ih systems using a surfncewulcr source, subsequent lailure tocomply with any one of Iho criteria foravoiding f i l iat ion also requires theinstallation of filtration treatment. Thus,beginning 30 r.ionlhs af ter promulgation

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1969 / Rules ond Regulations 27511

or 18 months jiflcr the Slol«,d«tcrmine*that a system is using a ground watersource under the direct Influence ofsurface water, whichever Is later. If thatsystem falls lo meet any one of thosecriteria (even If the system was meetingthe criteria for avoiding filtration up to(hot point). It must Install filtration andcomply with the requirements forfiltered systems within 18 months of thefailure. As with systems using a surfacewater source, in reviewing the datacollected by an unfillcred system usingground water under the influence ofsurface water, for the first 18 month*following the determination. It is up tothe State to determine how it will weighthe,data In deciding whether nitration isrequired.

Any system using a ground watersource that the Stale determines I*under the direct influence of *urfacewater that already ha* nitration In placeat the time of the State determinationmust meet the treatment techniquerequirements specified In 1141.73(nitration criteria) and 1141.72(b) •(disinfection criteria) and the monitoringand reporting requirements specified InII 141.74(c) and 141.75(h). respectively,beginning 48 months after promulgationor 18 months after the Slatedetermination, whichever <s later. *\

4. Strategies forimplemenlo-lion

To comply with this final rule, •system that uses surface water and doesnot currently disinfect Its water mustbegin disinfection, and possiblyfillrntlon. Whiln the system Is beingevaluated lo determine what treatmentneeds to be Installed (e.g., disinfectionwithout filtration: disinfection first andfiltration later because of timedifferences needed for construction: orfiltration and disinfection at the sametime), the Stale may determine thatinterim measures lo reduce risk tohealth (e.g., notice to consumers thatwater should be boiled before use ordistribution of bottled water) might beappropriate.

Similarly, for systems which arealready disinfecting, but do not meetone or more of the requirements foravoiding nitration, the State maydetermine that Interim measure* arenecessary to reduce risk to health (e.g,maintaining more stringent disinfectionconditions until filtration Is Installed).

Some systems already have filtrationand disinfection in place. While manysuch systems are already in compliancewith all the requirement* of the rule,other systems will require slgnificnntupgrodcs In treatment to meet all theperformance cnicria. As discussedearlier, filtration without disinfection.

with proper pretrcstmcnt whereappropriate, can be expected lo achieve09 to 99.9 percent (2- to 3-log) removal ofGiardia cysts and 90 lo 99.9 percent (1-to 3-log) removal of vlruSRft (Location,1907). Some disinfection will benecessary lo supplement filtration sothat the overall treatment achieves theminimum treatment requirements of therule. I.e.. 99.9 percent removal and/orInaclivation of Giardia cysts and 99.99percent removal and/or inoctivation ofviruses. To achieve these performancecriteria with a substantial margin ofsafety. EPA recommend* differentminimum levels of disinfection,depending upon the filtration technologyIn place. Table IV-2 summarizes thelevel of Giardia cyst and virus removalthat EPA recommends generally beassumed for different filtrationtechnologies (assuming they ere well-operated), and the correspondingrecommended minimum levels ofdisinfection needed for such systems tomeet the overall minimum performancerequirement*. CT value* for achieving 1-log inactivfttion of Gmrrf/o cysts arcIndicated in Table IV-3. CT value* loachieve O.S-log Inacllvatinn are one-halfthose Indicated In Table IV.3.Recommended CT values for achievingdifferent levels of virus Inncllvntion errindicated in Table IV-4.

TABLE IV-2. RECOMMENDED MINIMUM LEVEL OF DISINFECTION AND ASSUMED Loo REMOVALS BY FILTRATION METHOD

• . • • • . ' . • T —

r

Amn»d IOQ '•flitWHi

GUfOi

2.52.02.02.0

VhlMM

2.01.0201.0

ton* Oldi

64M*

O.S

101.0

•M^Atf Mk••iivunn

Vtruat*

20- JO

209.0

TABLE IV-3.—CT VALUES FOR ACHIEVING 1-Loo INACTIVATON OF GIAROIA LAMBUA '

CVff CM tf *,, ,. ,,.,.,..,. ' , „ -

QfOAt , ,. , . ,. , ,.

C^ptaf CV>**rff n

C*i*Q'i"lf"«t (ptflqffMt ) ' .._ - .... , , , ,,^

PH

e7I0

0.5 "C

4*TO

101146

OS721

1.270

Tempi

S-C

MSO72

14*0.03S.4

730

MM**

10 'C

2637547804*7.4

am

15 'C

1*28385*032S3

500..

i From 9/31 /M *«ll Outdanc* Manual. Vtlun to acn*va 0 S-tog «ae»vet*n art on* MM toot* tnown m ttw lab*• CT «*tum will vary depending en ih« eoncanaawxi o* KM ehtorina. InOcaltd CT vatoM an «o» 2.0 mg'l fcM cNonne (For ethot «i«e <**»**> ceocenirMian*.

(**' Gwd«ne* Manual.)

27512 Federal RegUter / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations

TABU iy-4.—CT VALUES FOR ACHIEVING INACTIVATION OF VIRUSES AT PHS 6 THROUGH 9 *

•

FrM smnmm

Oiooe ..,,,,.. - -- , ...

CrricNMie DKMtft *

rhi~»— >

I3f32323

O.S'C

a•0914| 4

25 •1.1432.063

Tempi

S*C

4

•Of09S6in

•471.423

tf(tt»t

:0'C

3404014 }lit

•431.067

15 'C

230.3O.Su• •

42t712

' CT ntfuei to *ee cNome. ozone, and chtonne dttude Include sately factor*. CT vejuoe tot chlocarnmee are baaed on laboratory data uwno pietermeacrtoiainne to nectweie Hepatoa A and do not Mode « safely lector (Sooaey. 18U).

' CT value* lor cruome aoada ware baaed on laboratory Hud»« at pH 6 (SobMy. 1966) Based on ftnled data, chtorlne dioxide appear* much more etlectiv* alhigner pHt. ProcediMe lor deinonairaH'ig * tower CT value* mar be appropriate w* be included in in* Anal Gurtance Manuel.

• CT value* lor enter an»ie« are oMy anphfaMe t eniorma » added pnor 10 ammoraa. Procedures toi demonavatng thai tower CT value* we appropriate wfl beincluded in me anal Guttnce Manual

Syitem* using chlorine with CTvalues that achieve die recommendedminimum level of inactivation forCtardia cysts will also achieve therecommended •"•'"im level ofinactivation for viruses. However, forother disinfectants. depending upon thenitration technology in place, the CTvalues for achieving the recommendedminimum level of virus inactive lion mayin some cases be higher than thosenecessary to achieve the minimumrecommended level of Ctardia cystinaclivation. Guidance for making thesedeterminations will be included in thefinul Guidance Manual

The degree of disinfection should becommensurate with the degree ofpotential pathogen contamination in thesource water and the type ofclarification and filtration. For example.the system should provide higher levelsof disinfection (e.g.. 99 or 96.9 percentinactivation of Ciardia cysts] whenthere is evidence of significant Ciardiacyst con trfmina (ion in the source water.Guidelines for providing an appropriatelevel of disinfection as a function ofsource water quality conditions and theextent of treatment processes will be

in the final Guidance Manual.

E. PuMit: NotificationOn October 29. 1987. EPA

promulgated regulations to revise) theexisting public notification requirementsin 40 CFK 141.32 to implement the 19Mamendments lo the public notificationprovisions in section 1414fcJ of the SafeDrinking Water Act. These regulationsspecify general notificationrequirements, including the frequency,manner, and content of notices, andrequire the inclusion of EPA-specifledhealth effects information in each publicnotice. The public notificationregulations divide violations Into twotiers bused on the seriousness of theviolation, with ouch tier huving differentpi.Uit nut i f ic i i l iun requirement:!. Tier 1

violations include violations of an MCL.a treatment technique requirement, or avariance or exemption schedule. SomeTier 1 violations are designated asviolations posing an "acute" risk tohealth. Tier 2 violations Includeviolation of a monitoring requirement,failure to comply with a testingprocedure prescribed by a NPDYVR. andoperating under a variance orexemption. Under this rule. || 141.70,141.71(c), 141.72, and 141.73 prescribetreatment technique requirements. Thus,violation of these requirements areclassified as Tier 1 violetlons. Violationsof 1141.74. which prescribes testingprocedures and monitoringrequirements, are classified as Tier 2violations. Violations of i 141.75(reporting requirements) do not requirepublic notification.

All of the requirements of 1141.32, thegeneral public notification requirements,including the manner and frequency ofnotification, apply to violations of thisFinal rule. The mandatory language to beincluded in public notices for violationsof the filtration and disinfectionrequirement* of this rule (i.e.. if 141.70.141.71(c). 141.72, and 141.73). includingan acute violation (i.e.. a waterbornedisease outbreak in an unfiltcredsupply), is specified below:

Microbiological contaminants (for usewhen lhe.-e is a violation of thetreatment technique requirements forfiltration and disinfection in Subparl Hof this pert). The United StalesEnvironmental Protection Agency (E£A)sets drinking water standards and hasdetermined that the presence ofmicrobiological contaminants are ahealth concern el certain levels ofexposure. If water is inadequatelytreated, microbiological contamir.ants inthat water may cause disease. Diseasesymptoms may Include diarrhea,cramps, nausea, and possibly jaundice,and uny associated hcudiic.hcs andfatigue. These symptom*, however, arc

not just associated with disease-causingorganisms in drinking water, but alsomay be caused by a number of factorsother than your drinking water. EPA baaset enforceable requirements for treatingdrinking water to reduce the risk ofthese adverse health effects. Treatmentsuch as filtering and disinfecting thewater removes or destroysmicrobiological contaminants. Drinkingwater which Is treated to meet EPArequirements is associated with little to.none of this risk and should beconsidered safe.

The above mandatory publicnotification language was changed fromwhat was proposed. Types of disease,namely hepatitis, giardiasis. andgastroenteritis, which might be causedby consumption of inadequately treatedwater, have been deleted. Also, wordinghas been added which indicates thatsymptoms which may be associatedwith consumption of inadequatelytreated water may be caused by otherfactors not associated with drinkingwater. These changes were made inresponse lo public comments whichexpressed concern (hut the geimntlpublic would not be familiar wilhdisease names such us giardiasis andgastroenteritis, and that most of thesymptoms mentioned in the notice areso common that the water treatmentplant might be considered responsiblewithout justification.

F. Variancu

Suction 1415 allows Slates to grantvariances from national primarydrinking water regulations under certainconditions. However, section141,:(b)(7)(C)(il) of the Safe DrinkingWater Act stales that, in lieu of thevariance provisions of section 1415, EPAis to specify criteria by which Stales willdelcrn.ine which public wuler systemswill be required to filler. This noticepromulgates Iliebu f i l l ru l ion criteria.

Federal Register / Vol. 54. No. 124 / Thursday. June 2fl.l9«9 / Rules nnd Regulotions 27_5jj

Accordingly, the rule does not permitvarinncea from the filtrationrequirements. At for the disinfectionrequirements in this rule. Uui to the•cute nature nnd high rUk associatedwith poor disinfection of surface water*,no variances ore allowed.

C. Exemption*Section 1-119 of (he Safe Drinking

Water Act allows a Stale to exempt anypublic water system within Hijurisdiction from any treatmenttechnique requirement imposed by anational primary drinking watefregulation upon a finding thofc

1. Due to compelling factor* (whichmay include economic factors), thopublic water system is unable lo complywith the treatment techniquerequirement:

2. The- public water nynlrm wn* inoperation on Ihe effective (lute of thetreatment technique requirement or. fora system that was nut in operation bythat dote, only if no reasonablealternative source of drinking walor itavailable to the new system: and

3. The granting of the exemption willnot reaull in an unreasonable risk tohealth.

If a Stale grants a public water systeman exemption, the Slate must prescribe,at the lime the exemption is granted, aschedule for \

1. Compliance (including uic.rumrnliof progress) by the public wnlcr systemwith each treatment techniquerequirement with respect to which theexemption was granted; and

2. Implementation by the system ofsuch control measures as the Stale mayrequire during the period the exemptionIs In effect.

Before prescribing a schedule, theState must provide notice andopportunity for a public hearing on theschedule. TTic schedule prescribed mustrequire compliance by the public watersystem with the treatment techniquerequirement as expeditiously uspracticable, but In no cast later thanone year after the exemption la issued(except thai, if Ihe system metis cei tainrequirements, the final date forcompliance may be extended for aperiod not lo exceed three years fromthe dftie Ihe exemption ia granted). Forsystems serving fewer than 500 serviceconnections, and meeting certainadditional requirements, the Slate mayrenew Ihe exemption for one or moreadditional two-year periods.

Under this rule, no exemptions areallowed from the requirement lo providedisinfection fur surface water systems,for the same reason variances art notallowed. However, exemptions areavailable to reduce the degree of

disinfection required. Exemption* fromthe filiation requirements are availableas well. For example, under certainconditions. It might be appropriate foran unfillercd system to receive anexemption, for a limited time. If itachieves only 09 perr.nnt Inactivation ofCiardm laniblia cysts (I.e.. it did notnecl the 99.9 percent inactivalionrequirement). Guidance fur determiningconditions under which an exemptionmight be appropriate is provided In thefinal Guidance Manual

V. Stale Implementation of Ihe SurfaceWater Treatment Requirements

A. GeneralSection 1-113 of Ihe Safe Drinking

Water Art establishes requirement* aPlnle must meet lo have primaryrnforremenl responsibility for publicwilr.r systems ("primncy"). Theseinclude: (1) Adopting drinking waterregulations no less stringent than theNPUWRa in effect under sections14l2(a) and H12(b) of the Act: (2)adopting and fmplemofttfng adequateprocedures for enforcement; (3) keepingrecords and making such reports withrespect to its activities as EPA mayrequire by regulation; (4) issuingvnrianr.es and exemptions (if allowed atoil by the Stale) under conditions nolex* stringent than allowed by sections1415 and 1410: and (5) adopting andbeing able to Implement an adequatepi.in for the provision of safe drinkingw.iler under emergency situations.

40 CFR Part 142 sols out the specificprogram implementation requirementsfor Stales to obtain primacy for Ihepublic water system supervision (PWSS)program as authorized under Section1413 of SDWA. EPA first promulgatedthese regulations on January 20.1976.Since 1976. however, much hashappened in Ihe PWSS program, andportions of the implementationregulations at 40 CFR Port 142 havebecome outdated. In response, onAugust 2.1083. the Agency propobeu*revisions lo 40 CFR Part 142. Subpart Bwhich lake Into account the program'sevolution since 1078. as well as Ihe newlegislative mandate* (63 FR 29194).These regulations, when promulgated,will specify the procedures and limingfor Slnles to follow In obtain approval ofprogram r.h.inget to adopt new orrevised regulations that EPApromulgates.

When today's regulations for surfacewater treatment were proposed onNovember 3.1987 (52 FR 42178). Iheschedule for revising Ihe implementationregulations (40 CFR Part 142) was nolknown. Consequently, theimplementation portion af the proposed

surf.ice water treatment rcqulrcrrnnisincluded a complete list of requircmrnlsfor States lo meet to obtain «pprovnl oftheir program revisions. Including bothgeneral requirements applicuble to allprogram revisions (e.g., regulations thaiare no less stringent than the NPUWR*Ihnt EPA promulgates In Part 141). n*well as specific requirements applicableonly lo the surface water treatmentprovisions. However. EPA experts topromulgate the revised implementationregulations shortly. TheseImplementation regulations will sponifyprocedures, timing, and other gcnemlrequirements a State musl meet to retainprimary enforcement responsibility. Forinstance, these final rules will make itclear that each time F.PA adopts (orrevises) nn NPDWR under section 1413.primncy S'nles must adopt drinkingwninr n:giilitll'tns Ihul are no Ins*stringent ihun (he new regulations.Therefore, today's amendments to Purl142 only address "special primaryrequirements," i.e., requirements tlmlare unique lo the surface walcrtreatment requirements promulgated inPart 141; general primacy requirementsapplicable to all NPDWRs are notaddressed In today's amendment of 40CFR P»rt 142.

In some respects, the Staleimplementation of Ihe regulations in 40CFR Putt 141. Suljpurt 11—Filtration nndDisinfection, is different fromimplementation of other NPDWRs. Thesurface wrier treatment requirementspromulgated today consist of bo!hobjective, uniform criteria and criteriathat provide Ihe primacy Stale branddiscretion lo decide whether toimplement them (and if ao, how),considering Ihe objectives of Iheregulation^ and the variabilityencountered in surface water troiHmrntthroughout the diverse geographicalareas of the United States

As a condition of primacy. Slatesmust promulgate regulations Ihntincorpomie requirements thai are noless Btriraent than these objectivecriteria in Ihe surface water trcMtmrnirequirement*. Since Ihe general primaryrule will require all Stale programrevisions to include requirements thntare nn less stringent than Federalrequirements, ludny's amendments *oPurl 142 do not list each provision of thesurface water treatment requirementsfor which the Stule musl adopt acorresponding revision which is no lessstringent (However, lo assist Slatesdeveloping program revisions to adopttoday's regulations. Section V.B.I. MowIdentifies such previsions)

Where it was nol possible to developuniform national criteria or where Sliilc*

27514 Federal Register / Vol. 54. No. 124 / Thursday. }unu 29,1989 / Rules and Regulation^

•re provided flexibility to modify thenational criteria to account for •Ite-•pecific circumstances, tlie surfacewnlcr treatment requirements give theStates discretion to adopt appropriaterequirements. For purpose* ofimplementation. EPA has divided theseiireui of State discretion into twocategories. For items in the firstaitegory, the State must demonstratethat it has adopted enforceablerequirements in the form of Slat* rules,regulations, and/or permit requirement*.For items In the second category, theState need only describe the practice* orprocedure* It will use to implementthose part* of it* program. The specificHem* in these two categories are listedin Sections V&2 and 3 btilow.

Where the State must haveenforceable rule*, regulations, and/orpermit requirements. I.e.. elements In thafirst category. EPA review of thisportion of the State program revisionwill generally be limited to adetermination that the Staterequirements are enforceable, ratherthan a detailed evaluation of the contentof the requirements per se. For item* inthe second category, where tha Stoleonly is required to describe the practice*or procedures It will use in exercisingthe discretion provided in the surfacewater treatment requirements. EPAreview of the Stale program revisionwill generally be even more limited. Itwill consider whether the Statepractices or procedures are clear andunambiguous. In both cases, however.EPA will consider whether the State'sprovisions can be reasonably expectedto accomplish the objective* of thesurface water treatment requirement*.

B. Specific Primacy Requirement forStates to Adopt 40 CFR Part 141 SubpartII—Filtration and Diiinfoction

The three types of provisions Stale*must adopt are described In greaterdetail below.

I. General Primacy Requirements—StateRequirements Must Be No Leaa Stringentthan Federal Requirements

As explained above, for thoevportions of the surface water treatmentrequirements promulgated today whichestablish objective criteria, primacyStales must adopt equivalent. I.e., noless stringent, requirements. Althoughthese objective criteria are not listed inthe revisions to Part 142 for the reason*described in the previous section. EPAhus, for convenience, summarized thesecriteria below. (Some of these criteriaullow exceptions on a case-by-casebdkis. as described in Purl 141. SubpartI1. These exceptions are listed inJ 142.1G(b)(2) (iii) and (iv) of the rule and

Section V.B.3 of this preamble. For eachprovision that allows exceptions, State*may choose to simply adopt therequirement a* lilted here (allowing forexception*), or permit the exception*described in the later section.) At a laterdate, specific guidance will bedeveloped and provided to States toassist them In preparing their programrevision*.

(a) Section 141.2—New definitions.(b) Section 141.32(a)(l)(iii)(D}—

Walerbome disease public notificationrequirement*.

(c) Section 141.32(e)(10)—Mandatoryhealth effect* language formicrobiological contaminant*.

(d) Section 141.70(a)(l)—Requirementfor 99.0 percent removal and/orinaclivation of Ciardia lamblia cyst*.

(e) Section 141.70(a)(2)—Requirementfor 89.99 percent removal and/orinaclivation of viruses.

(f) Section 141.70(b)—Compliancerequirements for public waler systemsthat filler and systems that do not filter.

(g) Section 141.70(c)—Requirementthat public water systems be operatedby qualified personnel

(h) Section 141.71—Deadline* forInstallation of filiation and compliancewith flllration requirement* for systemsusing a surface water source or groundwater under the direct Influence ofsurface water which do not meel all therequirements for avoiding filtration;deadlines for meeting criteria foravoiding filtration for systems whichchoose not to Tiller.

(i) Section 141.71(a)—Source waterquality conditions for public watersystems thai choose to avoid filtration,including:

(1) Section 141.71(a)(l}—CoNformlimit*.

(2) Section 141.71(a)(2)—Turbiditylimit*.

(j) Section 141.71(b}—Site-specificconditions for public waler syslems thatwish to avoid filtration, including:

(1) Section 141.71(b)(l)—Disinfectioncompliance requirement*.

(2) Section 141.71(b)(2}—Requirementto have, and mandatory element* of. awatershed control program.

(3) Section 141.71(b)(3>—Requirementthat system have an annual on-siteInspection that Includes the elements .specified.

(4) Section 141.71(b)(4)—Requirementthat system ha j not b en Identified a* asource of a waierbonn disease outbreak(or. if it was. that the system has beensufficiently modified to preventrecurrence).

(5) Section 141.71(b)(3J—Requirementthat system be In compliance with the

total collform MCI for 11 of the last 12consecutive months.

(0) Section 141.71 (b)(8)—Requirementthat system comply with totaltrihulomethane monitoring and MCLrequirements.

(k) Section 141.7l(c)—Treatmenttechnique requirements whose failuredocs not trigger filtration for publicwaler systems which do not filler.

(1) Section 141.72—Deadlines forcompliance wilh disinfectionrequirements for system* thai filter andthoie thai do not

(m) Seclion 141.72(a>—Disinfectionrequirements for systems which do notfiller, Including:

(1) Section 141.72(a)(l>—Requirementfor 99.9 and 99.99 percent removal ofCiardia lamblia cysts and viruses. •respectively, as determined by CTcalculation*;

(2) Section 141.72(a)(2)—Requirementfor either redundant component* orautomatic ihutoff;

(3) Section 141.72(a)(3)—Requirementthat water entering the distributionsystem have at least a <X2 mg/ldisinfectant residual concenlrullon; and

(4) Section 141.72(a)(4)(i)—Requirement for a detectable residual orcurtain HPC levels in (he distributionsystem.

(n) Seclion 141.72(bJ—Disinfectionrequirements for systems which filter,including:

(1) Section 141.72(b)(l}—Requirementfor 99.9 and 99.99 percent removal ofCiardia lamblia cysts and viruses,respectively, by the combined treatmentprocesses of the system;

(2) Section 141.72(b](2)—Requirement(hat water entering the distributionsystem have at least 0.2 mg/l .disinfectant residual concentration; and

(3) Section 141.72(b)(3)(l)—Requirement for a detectable re*ldual orcertain I1PC level* in the distributionsystem.

(0) Section 141.73—Requirements(including deadlines for compliance) forsystem* that provide filtration treatmentincluding:

(1) Section 141.73—Deadline* furinstallation of filtration equipment:

(2) Section 141.73(aJ—Turbidity limit*for systems using conventional or directfiltration;

(3) Section 141.73(bJ—Turbidity limitsfor system* uiing slow sand filtration;

(4) Section 141.73 (c)—Turbidity limitsfor syslems using diatomoceous earthfiltration; and

(5) Section 141.73(d)—If the Slateallows alternative filtrationtechnologies, the requirement that suchtechnologies, at a minimum, meo1 the

Federal Regular / Vol. 54. No. 124 / Thursday, fune 29.1989 / Rules and Regulations 27515

turbidity limits for systems using slow•and nitration. r

(p) Section 141.74(«H-Requlrom»-nfthe I only F,PA-approved analyticalmethod* be used to demonstratecompliance: requirement thnt inolyiesfor total colirormi. fecal colfforms. andhelerotrophic bacteria be conducted bycertified laboratories, and thatremaining measurements (pH.temperature, turbidity, residualdisinfectant concentration) be made bya party approved by the State.

(q) Section I41.74(b)—Monitoringrequirements for systems that do notprovide filtration treatment, Including:

(1) Section I41.74(b}—Deadlines forcompliance with monitoringrequirements:

(2) Section 141 (bM!)—Coliformmonitoring requirements:

(3) Section 14174(b)(2>—Turbiditymonitoring requirements;

(4) Section 141.74|b)(3}—Monitoringrequirements and methods forcalculating CT values:

(5] Section 141 74(h)(4}—Method forcalculating Inactive tion ratios:

(9) Section 141 "4—Tables 1.1-1.6. t\.and 3.1 (CT values1

(7) Section 141 ~< b)(5}-D!sfn/ecUntresidual monitoring requirements forwater entering the distribution system:and „

(8) Section H1.?4(b)(»))(l}— vDisinfectant residual monitoringrequirements for water In thedistribution system.

(r) Section 141.74(c)—Monitoringrequirements for systems that providenitration treatment, including:

(1) Section 141.74(Cr-Deadllnes forcompliance with monitoring,requirements:

(2) Section 141.74|c)(l)—Turbiditymonitoring requirements:

(3) Section 141.74(c)(2>—Disinfectantresidual monitoring requirements forwater entering the distribution system:and

(4) Section 141.74(cH3)(ir—Disinfectant residual monitoringrequirements for water la thedistribution system.

fi) Section 141.75<aMbportiBfrequirement for syslaof which do notfilter, Including:

(1) Section 141.75(a}—Deadlines forcompliance with reporting requirements;

(2) Section I4l.75(a)(1}—Source waterquality reporting requirements:

(3) Section l41.7S(a)(2)—Disinfectionreporting requirements:

(4) Section 141.75(a}(3)—Watershedcontrol program reporting requirements:

(5) Section 141.75(aJ(4)—On-slleInspection reporting requirements; and

(6) Section 141.7S(a)(5)—Reportingrequirements when there Is awalerbome disease outbreak, certain

turbidity violations, and failure tomaintain a disinfectant residual enteringthe distribution system.

(I) Section 1-tl.75|b]—Reportingrequirements for public water system*that filter, including:

(1) Section 141.75(b)—Deadlines forcompliance with reporting requirements;

(2) Section I4l.75(b)(l)—Turbidityreporting requirements:

(3) Section 141.75(b){2}—Disinfectionreporting requirements: and

(4) Section 141.75(b)(3)—Reportingrequirements when there Is awaierborne disease outbreak, certainturbidity violations, and failure tomaintain a disinfectant residual enteringthe distribution system.

(ti) Section 142.64— Limits on Staleissuance of variances and exemptions.

(v) SOW A section l412(b)(7)[C)fii>—Requirement for procedures to providenotice and opportunity for publichearing for determination of whether apublic water system shall adoptfiltration.2. Special Primacy Requirements—SlateRequirements Musi Be Enforceable

State program revisions to adopt (hesurface water treatment requirementspromulgated today In Part 141. SubpartH must include enforceablerequirements that specify design and •opnrating conditions for all disinfectionand filtration treatment processes and/or equipment used by public watersystems to comply with 40 CFR 141.70.141.71.141.72 and 141.73. Alternatively(or in combination with enforceable •design and operating conditions), theState may establish a procedure forsetting enforceable design and operatingrequirements on o system-by-systnmbasis (e.g., a permit system).3. Special Primacy Requirements—StateMust Establish Practices or Procedure*

An application for approval of a Slateprogram revision must describe thepractice* or procedures thai the Stalewill use to Implement provision* of thesurface water treatment requirementsthai provide the Slate flexibility withrespect to how the objectives of theregulation are to be achieved. ExamplesInclude the authority to modify certainmonitoring, analytical, performance, andreporting requirements; approve —-alternate disinfection processes ortechnologies: determine whether thecombination of treatments providedachieve the required level of removaland/or disinfection: establishqualifications for public water systemoperators and parties conducting on-slteinspections; and determine whichsystems supplied by ground water areunder the direct Influence of surfacewater.

It Is important to note that theseprovisions take (wo forms: Provisions InPart 141. Subpnrt H. that give the Stainsfull implementation discretion andprovisions that allow the Slate In modifythe stated requirements under certaincircumstances If the State so chooses.The corresponding primacyrequirements depend on the category ofthe provision.

For each of the provisions in '| I42,15(b)(2)(l). which fall in the firstcategory, Stale program revisions muslInclude a description of the practicesand procedures (or regulations, if theycover these items) that explain how theState will exercise Its discretion.Likewise. Slates which allow publicwater systems to avoid filtration bymeeting the requirements of 1141.71musl also submit the practices andprocedures (or regulations) describinghow they will exercise their discretionfor each of the provisions listed In1142.1B(b)(2)(ll).

Provisions In the second cu letory elitelisted in 1142.16(b)(2)|lli) (which are"options available to all Slates) and In1142.16{b)(2)(lv) (which are optionsavailable to Slates that allow systems toavoid filtration by meeting the -requirements of 1141.71). For each ofthe provisions In this second category,the Slate needs to submit proceduresand practices (or regulations) thatexplain how It will exercise thediscretion allowed only for thoseoptions II plans to exercise. Forinstance. If the State does not plan to setalternative turbidity limits underi 141.73 (a)(l) or (b)(l). Its programrevision need not address Ibis provision.I.e.. it need not submit anything under1142.16(b)(2)(lil)(C).C. State Reporting and RecontKfvniiixRequinmtntt

Today's notice amends 40 CFR Part142 lo require Slates with primaryenforcement responsibility to retainrecords and report Information lo EPAsufficient to ensure adequate oversightof the States' activities to implement thesurface water treatment requirement*.Specifically, States must • .

(1) Retain for not less than one yearrecords of microbiological analyses. I.e..analyses for total conforms, fecalcollforms. and heterotrophlc plate count(in both finished water and sourcewater], in a form which makes possiblecomparison with the total coliform, fecalcoliform. and helerotrophic plate countlimits specified In 40 CFR 141.83,141.71.and 141.71

(2) Retain fur not less than one year .records of disinfectant residualmonitoring and other parametersnecessary to document disinfection

27516 Federal Register / Vol. 54t No. 124 / Thursday. June 29.1989 / Ru^es ar.a Regulations

effectiveness in accordance; withI 141.72. Reports submitted by publicwater systems must comply withi 141.75.

(3) Retain for not less than one yearrecords of turbidity monitoringnecessary to document nitrationeffectiveness in accordance with1141.73. Reports submitted by publicwater systems must comply withi 141.75.

(4] Retain, for specified periods,records of determinations made by theState where the State has exerciseddiscretionary authority allowed byi 142.10(b). This discretionary authorityincludes modified monitoring,analytical, performance, and reportingrequirements, as wall as authority toqualify operators or approve on-siteinspectors. Where such decisions aremade on a system-by-system or case-by-case basis, the State must keep a recordin its files which documents thatdecision. A State is required to providea formal, written notice of certaindeterminations to the system (e.g..reduced monitoring and substituteturbidity limits), and It may want to doso in other instances to preventconfusion on the part of the system orother purty. Appropriate cases couldinclude notification of qualifiedoperators and approved on-slleinspectors. A list of determinations, forwhich these records must be kept isincluded in the rule promulgated todayin 1142.14(a)(41(ii).

(5] Retain indefinitely records of anydetermination under 1141.71 that apublic water system using a surfacewater source or a ground water sourceunder the direct influence of surfacewater is not required to providefiltration treatment.

(0) Report annually (he name andPWS identification number of eachpublic water system using a surfacewater source or a ground water sourceunder the direct influence of surfacewater (hut the Suit lias determinedneed not provide nitration treatment,und thu date thai the State made thedetermination for each such system.

(7) Report annually the name andPWS identification number and date ofeach determination of each public watersystem supplied by a surface watersource or a ground water source underthe direct influence of surface water thatthe Stale determined is providingadequate disinfection even if the systemis not meeting the criteria for residualdisinfectant concentration specified byi 141.72(a)(4)(i) or 141.72(b)(3)(i).

(8) No:ify EPA within 60 days of theend of each calendar quurtor of anydetermination that a public watersystem using a surface water source or a

ground water source under the directinfluence of surface water is notrequired to provide filtration treatment.

D. EPA Oversight of State Decision*Regarding Filtration Requirement!

EPA intends to periodically reviewSlates' decisions as to whether publicwaier systems supplied by e surfacewater source or e ground water sourceunder the direct Influence of surfacewater are required to provide filtration.EPA will use procedures similar to thosespelled out in Section 141S(a)(l)(F) of theAct for EPA oversight of variancesissued by Stales. EPA considers this tobe an appropriate procedure for reviewof filtration decisions since (1) the Actlinks filtration determinations anddecisions on variances by requiring EPAto specify "in lieu of the variancerequirements of Section 1415"procedures by which States are todetermine which public water systemsmust adopt filtration, and (2) thefiltration and variance decisions aresimilar in nature. Essential elements ofthis procedure which appears at 40 CFRPart 142, Subpart I include: (1) Reportingby Slates of filtration decisions; (2)periodic review, preceded by FederalRegister notice, of State filtrationdecisions by EPA; (3) notice to the Stateif the Administrator finds the State hasabused its discretion in making nitrationdecisions: (4) an opportunity for theSlut* to taka corrective action: (5) apublic hearing conducted by a hearingofficer to review testimony; and (6) afinal decision by the Administrator thatupholds or rescinds the finding that theState has abused its discretion. In theevent the Administrator finds that theState hes abused its discretion, (s)hewould revoke decisions with regard tofiltration made by the Slate and/orrevoke any compliance scheduleapproved by the Slate.

It is important to note that EPA neednot undergo these procedures prior totaking an enforcement action against aspecific public water system for failureto comply with loday's rule. if. forinstance, the State has determined thatthe system (s not required to filter, butthe system Is not complying with iherequirements for avoiding filtration.Likewise, promulgation of theprocedures in Part 142, Subpart I doesnot preclude EPA from using otherappropriate means to ensure that the.Stale exercises its discretion properly.Such measures may Include grantconditions or Initiation of primacyrevocation procedures when there isevidence that a State is not makingappropriate filtration decisions.

£ Response to Comment* on ProposedRequirements for State Implementationof the Surface Water TreatmentRequirements

Commenters on the proposed surfacewater treatment requirements and theassociated proposed implementationregulations at 40 CFR 142.16 (52 FR42178. November 3. J987) generallyfocused on the requirements addressedto public water systems in the primaryregulation (i.e.. the Part 141 provisions)rather than the proposed Slateimplementation requirements. However,some commenters did express concernthat the proposed SWTRimplementation regulations wouldrequire them to adopt enforceableregulations, which EPA coulddisapprove, without EPA having topropose and receive comment on theappropriate criteria for approving suchrevisions. Some commenters alsoexpressed concern that EPA. through theprimacy review process, would attemptto establish uniform national criteria fortreatment requirements that would notaccount for local variability. Finally,some commenters were concerned thatthe proposed amendments to i 142.17(special primacy requirements,promulgated today in 1142.16) Impliedthat States must adopt provisions toexempt some systems using surfacewater sources from the filtrationrequirements. Other commenterssuggested that EPA was asking for toomuch Information from both systemsand Stales.

In the final rule, EPA has revised theState implementation requirements inresponse to commenters' concerns. First,EPA expects to promulgate revisedgeneral Implementation regulationsshortly; these revised provisions willestablish standard procedures, timing,and other requirements States mustmeet to revise their programs followingpromulgation by EPA of new or revisednational primary drinking waterregulations. Accordingly, the generalStale program revision requirements inthe November 3,1987, notice are notincluded In today's final rule. Since theforthcoming amendments of the primacyrule will require thrfl. whenever EPAadopts new or revised NPOWRs. Stalesadopl requirements no less stringentthan these NPOWRs. it is not necessaryto list each new requirementpromulgated in Part 141 In Part 142 uswell. As a result. Ihe list of specialprimacy requirements to adopt thisregulation has been significantlyreduced. Special primacy requirementsare limited to those Included in 40 CFR

Federal Register / Vol. 54. No. 124 / Thursday. )une 29.1989 / Rules and Regulations 27S17

142.16{b). promulgated today (anddescribed earlier).

Today '• Implementation provisions (inboth the regulation and preamble) makeII clear that EPA it not establishinguniform national treatment requirement!through the program revision process.States are given a great deal ofdiscretion in Implementation; manyprovisions In the final rule may bemodified by the Stale* In npproprintccircumstances. Also, (he languagepromulgated in { 142.t6(b)(2) clearlyIndicates that Slates have the c-riion torequire that all public water sys 'emsusing surface water sources or ruundwater dlrtci'y influenced by sur, -jtwater provlu~ filtration trealmcr.

Finally, th* •mount of public wetcrsystem repon ng to States has brenreduced tc 'he lowest level practicable.Tills redact* the State recordkcrpingrequirements aa well. In addition, thenumber and frequency of reports Stalesare required to provide EPA has beenreduced. Those that remain nreconsidered essential for EPA to performIt* oversight function.VL Economic Analysis

Under Executive Order 12291. EPA 'must Judge whether a regulation is"mojor" and therefore subject to therequirements of a Regulatory ImpactAnalysis. This action constitutes a"major" regulatory action because Ifjvillhave a major financial or adverse :

impact on the regulated community ofover $100 million per year. Therefore.EPA prepared a Regulatory EconomicImpact Analysis for both the proposedand final rules and submitted them tothe Office of Management and Budgetfor review. In the draft RIA (USEPA,1087c), the capital cost was estimated tobe $2.0 billion, and the annuallzed cost$338 million.

In response to public comments on theestimated coal of complying with therule as proposed. EPA made severalchanges In Its estimating methodologywhich resulted In a significant Increasein the projected compliance cost. Thenature of these changes, and theircorresponding effect* on the originalcost estimates, are described below.

1. Land, piping, and pumping costs innewly installed filtration plonlt. ThoseItems were not Included in the earlieranalysis because they are highly site-specific. Including these costs IncreasesEPA's previous estimate by $685 millionfoi capital, or $121 million/year on anennualized basis. It should be borne Inmind, however, that the costs used areextremely rough estimates. •

2. Disinfection for filtered tyitamt. Atthe time of proposal. EPA did notinclude any costs for upgrading

disinfection practices because the ' 'Agency believed that most systemswere already complying withdisinfection standards similar to thosein the proposed rule (e.g.. the 'Ten-StateStandards"). Subsequently. EPA learnedthct. In fact, many systems will need toupgrade their disinfection practice tocomply with the disinfectionrequirements of this rule, and hasadjured Its cost estimate accordingly.F.PA expects systems to expend anestimated $258 million In capital cost*for improved disinfection. On anenrua l ized basis, this amounts to anadiii:ional $27 million/year.

C..ier costs which commenlerssuggested EPA should Include In theestimate have not been estimated, asexplained below:

1. Covering open Hittributionreservoir*. Apparently, somecnmmrnlcrs thought this was arequirement of the proposed rule. This IsIncorrect. Such a requirement was notport of the proposed rule and Is notrequired In the final rule, either.Therefore, the cost of coveringreservoirs Is not considered to be acompliance cost Imposed by this rule.

2. Preparation of environmentalimpact ttatementt and mitigation ofenvironmental impact*. Costs for these-*Items are highly site-specific. To projectthem with any degree of accuracy wouldrequire an engineering cost study ofeach system in the U.S. Clearly, this isnot possible. Also, relative to othercosts, these costs are not expected to besignificant. Therefore, the final RIA(USEPA. 1889a) does not assess thesecosts.

3. Installation of meters andcorrection of leaks in the distributionsystem. EPA agrees that. In systemsexperiencing high rales of leakage. Itmay well make good economic sense to'correct excessive leaks In view of thehigher cost of produced water resultingfrom compliance with this rule. •Likewise, unmetered systems lend to •encourage extravagant use and theadditional costs Impoaed by this rulemight cause operators to fenl that theprovision of unmetered water can nolonger be justified. Nevertheless, thecorrection of leaks and installation ofmeters are economy measures and arenot required to achieve compliance withthe rule. Therefore, their cost Is not—properly attributable to theserequirements. (Even If such costs wereattributable to the rule, they should beoffset by the savings from the reductionIn leakage and wasteful use. In fact II laconceivable that, over the long run. suchsavings could largely offset the cost of -compliance with this rule.) Flnnlly. the •cost of correcting leaks Is highly site-

specific and EPA knows of no way tomake a reasonably accurate estimate ofsuch costs other than performingengineering studies at each affectedlocation, which clearly is not feasible.Baaed upon these considerations. EPAhas not Included any costs for leakcorrection and meter Installation.

The following sections summarizeEPA's detailed cost analysis providcilelsewhere (USEPA. 1907c. 1989a).

A. Total Cost of the Final RuleThe filtration and disinfection

requirements of this rule will Imposecosts on four groups of public watersystems using surface water sources:

1. An estimated 1.346 communitywater systems that ace currentlyunfiltered

2. An estimated 1.536 non-communitywater systems (hot are currentlyunfillnrcd (non-community watersystems Include systems servingtransient end non-transientpopulations).

3. An estimated 4.611 communitywater systems that are currently filtered.

4. An estimated 2.308 non-communitywater systems that are .currently filtered.

There are, there/ore, an estimatedtotal of 2.882 water systems that arecurrently uriflltered and &919 systems(hat are currently filtered which will beaffected by this rule. All 2,862 unfiltercdsurface water systems will incur somecosts under this rule. However, systemsthat meet the specified requirements foravoiding filtration will not incur thecosts associated with installingfiltration.

Of the estimated 0.910 filtered surfacewoler systems. EPA estimstes thatabout 5.128 will Incur total snnualizcdcosts of $113 million per year to upgradetheir systems from their current level ofperformance to meet the hew turbidityrequirements. Were all of them incompliance with the existing (interim)national primary drinking waterregulation* at this lime. Inejinnualizeticost to the nation would be only $95million per year. However. EPAestimates that 1.409 systems are not.Thus, these systems will have lo domore than those In compliance with theInterim rule to meet the newrequirements. For those deficientsystems, the additions! cost of meetingthe new regulations Is $10 million peryear. The annualized cost of $05 millionIs considered lo be the "Incremental"cost of this rule because it is based on acomparison between the cost ofcomplying with the new requirement*and the cost of complying with lh«interim regulations (assuming 100percent compliance). The

2751B Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations

cusi of $113 million it considered lo beth« -«ot«J~ con of today'* nil* becauitit (nfes into account the additionalexptnae to be incurred, by system* notpresently complying with the interimregulation*.

The tame 8.919 filtered water systemswill also be subject to the disinfectionimrforaunce requirement*. As discussedearlier, at the time of proposal, thesecusU were not believed to be significant;uid thus were nol included in theestimates. It is now estimated thatapproximately 1,200 of these system*

will have to upgrade their disinfectionpractices. el e cost of S27 million/year.EPA also has estimated compliancecosts for systems using a ground watersource under the direct influence ofsurface water. These systems will incurcapital costs of $164 million andannualized costs of $11 million per year.

All systems subject to this rule, exceptthosa'which ere able to evoid filtration,will Incur incremental annuitizedmonitoring costs of $17 million. The totalannualized monitoring cost of $18million lakes Into account the additional

expense lo be incurred by systems notcurrently complying with the Interimmonitoring regulations. Monitoring costsfor systems that meet the criteria foravoiding filtration were counted us costsof treatment for unfillered systems.States'wil) Incur annualizedimplementation costs of $12 million.

The estimated costs of the proposedand final surface water treatmentrequirements are presented in Table VI-1.

TABLE Vl-1.—PROJECTED COST OF THE PROPOSED AND FINAL SURFACE WATER TREATMENT REQUIREMENTS

COM category

TrMttMnr Aaouranwntf""Mil 111 Syttami (frUtaSog or availing lUfateon) . .FriMrad Syrtaffla

Twfadtty RefectionIncr+ffupuil ,.,„_. ,.r, . . . . . . , . .

TOWOlfMtC**! , .., . . , .. .

5i*ftri 'n'm-na Ground Wily Syttama ...... ,.

AJ Striae* Systamt Ewapt ThoM AMe to AvoW FAratton '

ToialStaff fregem Cottt

Cotton**hvianmnalTffH*

Costs upropM

CapaatCOM#m>

1613

333NA

00

saMA

0

2004HA

ndvf *ia

Amu*bedooat

On*/*•)

ait

MNA

00

20NAr

33*NA

CapitalCOM(Hwfl

230*

3334032sa1*4

30300

309331*3

Annual-aadcoal<*ni/Pi

337

M1132T11

17ItIS

4*eSI*

NA»nol appfccatt*1 Fix ttw pioiactad 1* paroani el systems abi* lo avoid ftftaton. «* motoring costs

costs of Mstmant lor unMtarad tyttamt.auotiatad with maaiing lha criteria te» avoidtag Mraton an Indudad as

0. Concspts of Cott Anafy»is

Capital, operating, and annualizedcosts for individual nitration anddisinfection technologies appear In"Technologies and Costs for theRemoval of MicrobiologicalContaminants from Potable .WaterSupplies" (USEPA, 1988b).Th*unnualizing procedure uaed io thatdocument is Intended lo reflect theactual financing cost that a typicalwater system might face In capitalmarkets, i.e, it is an estimate of the"market" cost. However, the totalannual cost estimate of $fll3 milliondiscussed above (see Table VH) Isintended to represent the total "social"cost to the nation for purpose* ofmaking benefit/coal comparisons. It I*computed using a different discountrule. The discount rate used lu assess"market" cost is ten percent. This ismade up of three components: (1) A riskpremium (reflecting the market's.issestmcnl of the risk of dcfuull); (Z) an

inflation premium (reflecting themarket'* expectations about theeconomy); and. (3) the true carrying costof capital (the time value of money). Thefirst two component* ere financialconcept* while the third Is both afinancial and an economic concept The"social" discount rate consists only ofthe third of these three componentsbecaui* the benefits to which costs arebeing compared are a risk-free,inflation-free economic concept. Threepercent was selected for use in theseanalyse*.

An analysis of costs based on thefinancing options a typical system mightface in capital markets appears in FigureVM.C. Cotti of Compliance for CurrentlyUnfiltend Surfoct Wat«rSyst*m$

EPA based its *stimates of the numberof community and non-community watersyslems that are currently unfiltered ona survey conducted by the Associationof State Drinking Water Administrators

(ASDWA. 1968). EPA estimated the totalnational cost of compliance for the 2.882currently unfiltered system* using astraightforward procedure forforecasting likely compliance choice*.Predicted compliance choices for the2.887 system* which each serves fewerthan 100.000 people, appear in Table VI-2.

TABLE V1-2.—PREDICTED COMPLIANCICHOICES FOR UNFILTERED SVSUMS

NumbefOlsytiame

4S7

*M

221it•9

115990

M

Proiactad action

Maal (•quvamantt tor avoidington.

Smtch to an atamaia vaiar teuot(ground or purcnatad).

mtialf a pacug* uaaimant plantkimaV conventional VMimantinata* dfcact inviuon.Install ditiomacacu* •amInstaH now sand uuioortInstall unttliivahon.

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations 27519

EPA based the forecasts of..compliance choices largely on thecomparative costs of the differentoptions. The Agency predicted that slowsand filtration, switching to ah alternatesource, and package treatment plantswould be popular solutions due to therelatively low costs of thesetechnologies compared to othertechnologies and the preponderance ofsmall water systems among thoseaffected (over 90 percent of currentlyunfiltered water systems serve fewerthan 10.000 people).

It is important toiiote that a urgeproportion of total costs for currentlyunfiltcred systems Is attributable to asmall group of fifteen unfiltered systemswhich each serves more than 100.000people. These fifteen systems accountfor approximately 40 percent of the $510million total annualized cost However,

these fifteen systems also serveapproximately 16 million of theestimated 21.4 million people exposed tounfiltered surface water (75 percent).

As discussed above, the costestimates presented with the proposedrule did not include certain site-specificcost elements, such as land costs andcosts of additional piping and pumping,due to 'he difficulty of assessing thesesite-specific factors. EPA believes thesecosts could increase the total cost ofinstalling filtration on the order of $695million, or $121 million per year on anannualized basis, over the originalestimate.

Figure VM illustrates the systemlevel market costs of complying with the'filtration requirement for system sizecategories serving fewer than 100.000persons. The costs shown represent theapproximate high and low extremes of

Ihc cost of installing filtration. Forsystems serving fewer than 10.000people. EPA used slow sand nitration asthe basis for the low-cost estimate andpackage treatment as the basis for thehigh-cost estimate. For systems servingbetween 10.000 and 100.000 people. EPAused direct filtration to represent thelow-cost case and conventionaltreatment for the high-cost estimate.System level costs for installingfiltration in the 15 large systems, i.e.. thesystems which serve more than 100,000persons and not represented in FigureVH. were based on a case-by-cascassessment of the actual types and sizesof filter plants that might be built inthose cities. These costs ranged from$0.37 to $072 per thousand gallons ofwater produced.aujMO coot uta-w-M

FIGURE VI-1

Cost of Installing Filtrationin Systems Serving < 100,000

1200$'• Per Household Per Year

1000 -

800

600

400

200

25-100 101-500 501-1K 1K-3.3K 3.3K-10K 10K-25K 25K-50K 50K-76K75K-100K

Population Size Categories

High Low

w-c

Below I OK PoimUtlonltl(h » pack«f« pUnl*low « «low Mi»4 pUnU

fbo»t IOK PopuUUonhtfh « con«cnllon«llow • Jlrccl (IUr*lt«n

ro

i

Ii.90

o

M

D.W

Inw

I(•

IC.

Federal Register / Vol 54. No. 124 / Thursday, )une 29.1989 / Rules and Regulations 27521

D. Costs of Compliance for CurrentlyFiltered Surface Water System*

EPA estimated the total national costof the turbidity performancerequirement* for filtered systems using •methodology which ufffized survey datafrom a random sample of over 500 watersystems, vtraftfied by system size. Thesurvey data provide a profile Of the typeof nitration technologies currently inplace and their turbidity performance. Asummary of the survey data is presentedelsewhere (ASDWA, 1986J. , ;

EPA estimates that the averagemonthly turbidity in the water Industryis currently 0.7 NTU. For the purposes ofthe Regulatory Impact Analysis, EPAassumed that the turbidity performancerequirement in this final rule (less than0.5 NTU. 65 percent of the time) forsystems using rapid granular mediafiltration. Le, direct filtration orconventional treatment (systems using -dialomaceous earth or slow saad haveless stringent turbidity performancerequirements), is equivalent to amonthly average of about 03 NTU. Fromthe survey data, EPA estimated thatapproximately 5.128 systems exceed thisaverage. Of these. 1.409 are estimated tobe in violation of the interim turbidityrequirement which is a monthly averageof 1 NTU.

EPA further subdivided the systemswhich currently do not meet theturbidity performance requirements inthe final rale by size and type offiltration process currently in place. Aforecast of the likely compliance choicesof systems In each nbcategory wasdeveloped. The compliance choicesevaluated Include various combinationsof the following: . .

• Hiring a consulting engineer to do adiagnostic analysis;

• Improving operation andmaintenance practices;

• Adding rapid mix:• Adding pH adjostaaal capability:• Replacing filter madias

• « Adding polymer. • ' . ' • •• Adding alum or FeCk• Adding ftocculation or contact

chambers.The system-level cost of each of the

above compliance options Is estimatedelsewhere (USEPA, 1987& IfiMa).Average system-level costs based onvarious combinations of these options.are thown in Table Vl-3. The totalnational capital cost, based on predictedcompliance choices, fa $403 million. Thetotal anrnjalized cost (s $113 million.

TABLE Vl-3.—COSTS OF UPGRADING ToMEET TURBIDITY PERFORMANCE RE-QUIREMENTS

TABLE vw.—COSTS OF UPGRADING ToMEET DISINFECTION PERFORMANCE RE-QUIREMENTS

Sfttun mx» (bf popdttton Mn*d)

MM ion101 to MO501 fc 1,000,. .,i/mft^MnJJOI-^OOOO10,001.9*,0009«fA1.«0000^«nnoo

Cora44/1.000otNon*)

n32•v15r32

<a

These national cost estimates forcompliance with the turbi: -requirements may be on th- nigh aidebecause the turbidity performanceprofile which underlies the analysis isbased on survey results which embody acertain amount of statistical error. Theforemost concern is that the surveysolicited data on monthly averageturbidity. Under the Interim turbidityrequirement. It is conceivable that thereare many water systems that aremonitoring well enough to documentthey are below a 1 NTU monthlyaverage, but not well enough todocument lower levels with precision.Measurement in the OJ NTU rangewould require greater care. Thus, someof the systems believed to be above amonthly average of OJ NTU may requireno more than better monitoring todemonstrate compliance.

On the basis of data developed in asurvey conducted by the AmericanWater Works Assoda lion (AWWA, •1987), EPA estimates that approximately1.183 filtered surface water systemscurrently do not meet the disinfectionperformance requirements of this finalrule and will have to undertakemodifications to upgrade theirdisinfection practices.

To meet the inactive lion levelsspecified in the final rule, systems areexpected lo choose from among severalcompliance options. Including:

• Increasing the chlorine or ozonedose;

• Baffling clearwen*;• Relocating the points] of

emmoniation/chlorinaUorc• Adding storage to Increase ,-

disinfectant contact time• Applying ozone or chlorine dioxide

as alternate disinfectants:• Combinations of the above.From this mix of compliance options,

assumptions were mads regarding theones which will be selected by systemsin different site categories, and theaverage cost of compliance estimated.The results are presented in Table VM.

tUn ipn ,_. - _. ,im MUMS01 10 1.0<X>1001 mj.TO" ,. „ •3901 to 10.00010 001 «B 94. 000 , „»I001 If, 40000

SQ001 HHOOOOB ,

>100,OOQ ,

Costs«/ 1.000«*nom)

61221064

3221

£ BenefitsIn the November 3.1987 proposal.

EPA estimated there are between212.000 and 470.000 cases of waterbornedisease annually in the United Statesamong persons served by surface watersystems, as described below.

• First EPA used data collected overa 15-year period by the Centers forDisease Control (CDC) on the number ofreported outbreaks (106) and the numberof cases of disease (34.436) to obtain anestimste of the average number ofillnesses per outbreak (325).

• Second, to compensate forwidespread underreporting in thenumber of outbreaks, the reportednumber above (106) was multiplied by afactor of four.

• Third, the adjusted number ofoutbreaks per year (424 divided by IS)was multiplied by the average numberof cases per outbreak (325) lo obtain anestimate of the number of cases ofdisease per year attributable towaterborne disease outbreaks. EPAconsidered this result (9.583 cases ofillness) the "lower bound" estimate.

• Next the "upper bound" estimate ofcases of illness was calculated. Tocompensate for underreporting in thenumber of casts of illness in *ytlemsserving 100.000 or fewer people, it wasassumed that half of the populationexposed during an outbreak episodebecame ill (This assumption replacedthe estimate of 375 cases of illness peroutbreak.) Using this approach, thenumber of cases of illness per year wasestimated to be 50.740.

• In addition, for systems servingmore than 100.000 people, it wasassumed that there would be twooutbreaks per year—one in a largefiltered system, and one in a largeunfillered system. Assuming an averageof 6.000 cases of illness per outbreak inlarge systems, based upon CDC data ofrecent record. EPA estimated that therewould be 12,000 cases of illness per year

27522 Federal Register./ Vol. M. No. 124 / Thursday, June 29.1989 / Rules and Regulations

attributable .to outbreaks in systems ., .serving more than 100.000 people.

• Finally, the 50.740 and 12.000 cases,calculated above, were added togetherto obtain a total of 62,740 cases ofillness, taking into accountunderreporting of the number of cases.

In addition to illnesses observedduring an outbreak, there arewulcrbome illnesses occurringthroughout the year, but not itsufficiently high rales to attract

attention as an outbreak. These endemicillnesses were estimated using adifferent methodology, as follows:

• First, it was assumed that the rateof giardiasis in unfiltered systems wassimilar, to that observed in townshipsadjacent to Luzeme County. .Pennsylvania, (i.e., one percent) at thetime a significant outbreak occurred in1983. For populations served byunfiltered systems, it was'assumed thatthe rate ranged from a maximum of one

percent to a minimum of one-quarter ofone percent. For filtered systems. »t w»«assumed that the rates were half (hoi*of unflltercd systems.

• Next, EPA applied ihese r«ies lo i>>opopulation served by filtered andunfiltcred systems to obtain an estimdieof the upper and lower bounds of ih«number of endemic cases of illness p«iyear (see Table VI-5).

TABLE Vl-5.—BASELINE NUMBER OF ENDEMIC CASES>EH YEAR AS ESTIMATED m THE DRAFT REGULATORY IMPACT ANALYSIS(USEPA. 1987C) • • • • • - . .

Endtmfc SMfy**

Unflttr«d lysMmt:(.»«0» fyiWfit (>1WOOO) .&n*f fyfumf {.{ '00 W)

Tot* unSJtmd .FilvMtrsurw1 yy tl-iltTf <»0"000) ,,

Tottt, aunri , ,

Assunwd•nMmc (•(•

Lo««bound

0.00250.006

1.00125ojooes

bound

00050.01

)00250.006

PopUikon

16MO.OOOS.646J63

21*ISJ53

34J16J6036.764.700

71053^60

•2.702.633

low*

•A-

CW4«/

*

40.00026JZ47

66J47

42.66161.611

134.779

Ktt.020

UPPI*bownt

CM««'f

60.000S6.4S4

136464

65721U3624

26*54}

40603*

• Finally, the lower bound estimates 'of cases of illness from outbreaks (9.183)and endemic illnesses (203.020) wereadded together lo obtain the lower endof the range of illnesses (212^03). Doingthe same for the upper bound estimates(82.740 + 400.039] resulted in anestimate of 468.779 total cases ofwaterborne illness.

Based on information submitted byseveral commentera. new data on theoccurrence of Giardia. and a revisedmethodology for the estimation of thenumber of endemic cases of illness,ihese estimates have been substantiallyrevised. EPA now estimates thaicurrently there are approximately 88.000cases of waterborne disease annually insystems using surface watar. This figurewas derived as follows:

• Using data on occurrence otCiardJain source water from Rose (1988) andestimates of treatment efficiences. EPAestimated the present exposure loCiardia of people served by filtered andunfilicred systems in different sizecategories.

• Next, these data were applied to adose-response model (Rose, 1988) todetermine the daily individual risk ofdisease'associated with the aboveexposure.

• The daily individual risk was (henconverted lo an annual risk and appliedlo the population served lo estimate the

number of cases of endemic illness peryear from giardiasis in the absence ofthe treatment requirements of this rule.

• Then, based on an analysis of the.relative rates of all waterborne disease,this value was adjusted upwards by 85percent to take into account diseasesother than giardiasis.

• Finally, the number of cases ofdisease which will be avoided bycompliance with the rule was estimatedbased on the increase in removal and/orinactivation of pathogenicmicroorganisms expected fromimplementation of today's requirements.

Using this methodology. EPAestimated that this final rule willprevent 79.854 endemic cases of diseaseper year. In addition. 9,294 outbreakcases will be avoided as a result ofcompliance with this rule. This numberwas estimated using the samtmethodology employed in the draftRegulatory Impact Analysis (USEPA.1907C) but is slightly higher (9.294 versus9.183 for the lower bound estimate)because of revisions to the data basesince the rule was proposed.

The total number of cases avoided peryear. 89.148. represents EPA's best pointestimate, or best single value, of thebenefits of the rule. The Agency alsocalculated an upper and lower bound,based on the 95 percent confidenceinterval around the dose-response curve.

By (his method, the number vf endemiccases could be as high as 149.181. or Mlow as 36,980. Thus, the total casesavoided per year could range from48.274 to 158.475. In addition. EPAbelieves that many more cases than tltenumber given may be avoided byimplementation of this rule because the 'number of cases per outbreak is.understated (it was not adjusted, as wasdone for underreporting in the number ofoutbreaks). Qy one account, theunderreporting in cases per outbreakcould be on the order of twenty-five .limes the actual levels reported(Hauschild, AJ. and Oryan. F~ 1980)

EPA also examined the net benefits ulInstalling filtration at the Individualwater system level Net benefits wereanalyzed for systems of various sizes byestimating the annual expected value ofeconomic damages resulting fromvarious levels of endemic and outbreakdisease incidence in communities ofvarious sizes and subtracting the annualcost of installing filtration.

It is important to nola that It Isdifficult to estimate (he value of (hebenefits associated with reducing theendemic and outbreak incidence ofwaterborne disc.tse. because (here a re-many benefits which cannot bequantified. As described at lengthpreviously (USEPA. 1987c). RI'A'sanalysis is structured upon hypothotic.it

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations 27523

assumptions which hive beendeveloped on th« basis of the insightsgained in two documented case studies:A1981 outbreak of viral gastroenteritisin Eagle-VaiL Colorado (Hopkins, 196C).«nd a 1983 outbreak of giardJasii inLuzerne County, Pennsylvania(Harrington. 1985). The damagefunctions derived from these studiesconsist primarily of two types of costs:(l) Direct costs of medical treatment andthe value of lost work, and (2) costsincurred due to "averting behavior" suchas boiling water or purchasing bottledwater undertaken in the event of tnoutbreak. While it hi difficult togeneralize from the results of casestudies. It ia currently the best means ofestimating damages.

Another shortcoming with the netbenefits analysis at the time of proposal,and perhaps the biggest one. Is thedegree of uncertainty in the assumptionsmade regarding both the endemic andoutbreak Incidence of waterbomedisease. It was estimated (Craun, 1987)that the annual probability of outbreakincidence to onfiltered surface watersyrtems—averaging all such systemstogether—Is roughly once fat every onehundred yean. Data with which toassess the endemic level of waterbomedisease (the sub-outbreak, baseline levelof disease) were not available at thelime of the November 1987 proposalTherefore, the net benefits analysis wasconducted in a manner Intended to showwhat assumptions regarding theendemic level of disease would have tohold true ia order to produce net.benefits near the margin (ia. the pointwhere net benefits approach zero),indicating that nitration is a breakevenor better proposition.

In the draft Regulatory ImpactAnalysis (USE? A, 1987c). an assumptionof an endemic level of disease of 04percent of the exposed population wasrequired to produce marginally positiveor marginally negative net benefits Inthe fifteen unfiltered systems servingmore than 100.000 persons, assuming aone percent annual probebtlity of anoutbreak (once every 100 years). Anendemic level assumption of 1.0 percentwas required to produce marginallypositive or marginally negative netbenefits tn systems serving between1.000 and 100.000 persons. It wes notpossible to produce positive net benefitestimates near tha margin for systemssen ig few*r than 1.000 persona.(En, .-mic level assumptions significantlyabove 1.0 percent were required; suchlevels would probably begin to becomeassociated with epidemic, rather thanendemic, incidence.)

The breakeven assumptions regardingthe probability of outbreak and theendemic level of walerbome diseasewere the subject of extensive commentson the proposed rule.

Several large systems stated that theprobability of outbreak, computed byaveraging all unfiltered systemstogether, yields an estimate whichoverstates the risk of outbreak in largesystems that have diligent watershedmanagement and disinfection programs.It has been contended that such systemscan reduce the risk of outbreak to alevel comparable to that achieved byfiltered systems (the reported outbreakrisk in filtered systems is 1/750 yearsAccording to Craun. 1987). Thisperception of outbreak risk in largesystems is consistent with the rationalefor providing criteria to avoid filtrationfor such systems in the proposed rule.On the other hand two systems amongthe fifteen unfiltered surface systemsserving more than 100.000 persons haveexperienced outbreaks since 1982,-suggesting there may be some largesystems for which the probability of anoutbreak ia greater than 1/750.

Many conunenters expressed the viewthat the endemic levels of waterbomedisease assumed In the net benefitsanalysts (5 X10"* for systems > 100,000;IxW'for systems OOaOOO) are muchhigher than the levels actually occurring.

As explained earlier, since publicationof the proposed rule, new informationhas become available which has made itpossible to assess the validity of theendemic level assumptions using *lexicological or dose/response,approach to estimation. The averageconcentration o{ Ciardia cysts in watersources with "pristine," or protected,watersheds has been estimated to be9xlO~'cysts per liter (Rose. 1986). AnEPA study (USEPA, 1988a) ofdisinfection practices at unfiltercdsystems shows that systems arecurrently achieving an average of 1.94 .logs of Inactivation. Thus, the impliedaverage dose to consumers is 4x10"'cysts/liter. A recently developed dose/response function (Rose. 1988) indicatesthai this exposure results in a daily riskof I.asxl0~'and is equivalent to anannual endemic rate of 3x10''. Thisestimated average endemic level ia"relatively cloae to the range of SxiO*' toix 10* * originally assumed to be theendemic level In the net benefitssnalysis at the time of proposal, lendingsupport to the validity of theassumption.

The above risk assessment indicatesthat unfiltered systems achievingaverage levels of innctivation may befacing greater risk of outbreak and

incurring higher levels of endemicdisease than may be evident from thenumber of cases reported. It should benoted however that since this estimateis based on average influent levels andaverage inactivation rotes, actual levelswill vary. Systems achieving higherinactivation rates are probably correctin their assessment that they are notexperiencing endemic levels on theorder of 10"'or 10'*. On the other hand,by definition, there also is variation onthe other side of the average estimate.Indicating that there may be systemswhich are experiencing endemic levelshigher than 3x10"'. In addition, it mustbe kept in mind that Ciardia is not theonly pathogen that contributes to theoverall endemic incidence ofwaterbome disease. Data reported tothe Centers for Disease Control indicatethere are 0.85 cases of other types ofwaterborne disease for every case ofgiardiasis. Thus, while it is true thatsome systems are not experiencing thelevels of outbreak risk and endemicincidence that are associated withbreakeven benefit/cost economics, it isalso clear that there are other water'systems which may fall within the rangeof the breakeven assumptions. Mostimportantly, then may be many watersystems in which it is not possible tomake a definitive assessment of the risk.

If the Ciardio occurrence datapresently available to EPA isrepresentative of unfiltered systems, thetreatment requirements will byrequiring a minimum of 3-log removaland/or inactivation of Ciardia. reducethe maximum daily risk—the risk ondays of peak occurrence—*o 4 J6xlO*fc.the average daily risk to 3.6X10*1; andthe average annual endemic level to8.57x10**. These levels providevirtually complete assurance againstoutbreaks caused by Ciardia cysts, aswell as most other pathogens, andassure negligible levels of endemicincidence. A significant additionalbenefit of the treatment requirements,therefore, is the confidence derived fromknowing they factor in an adequatemargin of safety.

As stated earlier, the estimated cost ofthis rule is approximately 50 percentgreater than that estimated «( the timeof proposal. When combined withsubstantially fewer cases of illnessavoided, the net benefits for systems indifferent size categories necessarilybecome less advantageous thanpreviously estimated. Bui the way lobest generalize about the effect onpublic water systems is not unequivocal.On the one hand, an analysis focusingon (he typical system in each sitecategory and using EPA'* best estimate

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations

of ihc benefits (Exhibit 5-10 of theRegulatory Impact Analysis) leads to theconclusion that household net benefitsmay be negative for currently unfilteredsystems required to install nitration,possibly as much at $262 per householdper year (in systems serving fewer than100 people). However, this interpretationis not entirely valid because this resultapplies to the typical system in each ofthese size categories, not to all systems.Moreover, the benefit analysis did notinclude ail business benefits; benefits,accruing from the avoidance of pain andsuffering: and benefits from reducedanxiety over the safety of the water.Since EPA's calculation is only a partialmeasure of benefits it is reasonable toconclude that actual net benefits in allsize categories may be greater. Inaddition, small systems unable to meetthe criteria to avoid filtration wouldprobably investigate less expensiveoptions than filtration, such asconversion to ground water orconnection to • larger regional watersystem, which will Increase the netbenefits. Under SDWA. exemptions arealso available. Under this provision, asystem might use interim alternativessuch as bottled water and point-of-usedevices, with State approval, therebyincurring lower compliance costs (atleast temporarily), and thus experienceconcomitant higher net benefits. In thecase of systems which do not servemore than 500 service connections andwhich need financial assistance for thenecessary improvements, the SOWApermits the exemption to be renewed forone or more additional two-year periodsif the system establishes that it is takingall practical steps and there is nounreasonable risk to health, therebyfurther reducing cost impacts.

Another way of evaluating thebenefit* of these requirements is toconsider the percent of the populationexperiencing positive and negative netbenefits. This is presented In Table VI-8. For the estimate of outbreakprobability most in keeping withavailable data (once in one hundredyears), systems serving approximately00 percent of the population will achievepositive net benefits, predominantlybecause currently filtered systems will .incur small costs to comply with therule. In most of the remaining systems,customers will generally pay only up toabout $20 more than the value of thetienefits quantified. Less than onepercent of ihe affected population isexpected to incur household net benefitsof minus S4Q or more, and these wouldonly occur in systems serving fewer •(tun 1.000 people. And thesepurceniMgcs would be even lowor if all

of the benefits had been captured in theanalysis, and alternatives to filtrationconsidered.

TABLE Vl-6.—PERCENT OF ' AFFECTEDPOPULATION INCURRING VARYING LEV-ELS OF POSITIVE AND NEGATIVE NETHOUSEHOLD BENEFITS WHERE THEPROBABILITY OF AN OUTBREAK is 1/100 YEARS

N« hOUMltoM bWMSU OVHH/Yl)

-20»0-40 to -20-Unttwn -«

Appro*IMti

t Of

SO

1

VTJ. Other Requirements

A. Regulatory Flexibility ActThe Regulatory Flexibility Act 5

U.S.C 802 et seq.. requires EPA toexplicitly consider the effect of proposedregulations on small entities. If there Is asignificant effect on a substantialnumber of small systems, the Agencymust seek means to minimize theeffects. EPA has concluded that thisfinal rule will not have a significanteffect on a substantial number of smallentities, for purposes of the RegulatoryFlexibility Act

The Small Business Administrationdefines si "small water utility" as onewhich serves fewer than 50.000 people.There an about 190.000 public watersystems using surface and ground watersupplies which are considered smallsystems under this definition. Of those,about 11,000 systems are expected toincur total annualized costs of $333 to$439 million per year to comply with therule. Compared to total operatingexpenses of $147 billion per year (orthis group, the cost of complianceamounts to an Increase of 24 percent to3.0 percent over current operating costs.EPA believes that an Increase of thismagnitude Is not • substantial economicimpact within the meaning of theRegulatory Flexibility Act However.EPA recognizes that today's actioncould have a substantial effect on somesmall systems. Therefore, the Agencyhas attempted to provide lessburdensome alternatives to achieve therule's goals for small systems whereverpossible. To Illustrate:

• With respect to monitoring of thedisinfectant residual at the entry pointto Ihe distribution system, systemsserving fewer than 3.300 people maylake grab samples in lieu of usingcontinuous-monitoring equipment:

• With respect to disinfectantresiduals in the distribution system,systems which are unable to maintainsuch residuals will still be considered incompliance if the Slate determines thatit is not feasible for that system tomonitor for HPC, and that disinfection isadequate, based on a review of site-specific considerations (e.g., sourcewater quality, past coliform monitoringresults);

• With respect to Ihe turbiditymonitoring, for filtered systems servingfewer than 500 people, the State mayreduce the number of samples to one perday if it finds that the historicalperformance and operation of thesystem indicates effective particleremoval under the conditions expectedto occur In that system.

In addition, many of the provisions ofthis rule allow the State to modify thestated requirements In appropriatecases, regardless of system size.Although not specifically aimed atreducing the burden on small systems,these systems may avail themselves ofsuch flexibility in the same manner aa

. their larger counterparts.

B. Paperwork Reduction Act

The information collectionrequirements contained in this rule havebeen submitted to the Office ofManagement and Budget (OMB) underthe provisions of the PaperworkReduction Act 44 U.S.C. 3501 et icq. TheInformation collection requirements arenot effective until OMB approves themand a technical amendment to thateffect Is published in the Federal 'Register:

The public reporting burden on publicwater systems for this collection ofinformation is estimated to average 0.1hours per response (i.e, sample taken,or report submitted to the Slate or EPA),including time for reviewingInstructions, searching existing datasources, gathering and maintaining thedata needed, and completing andreviewing the collection of information. .

Send comments regarding the burdenestimate or any other aspect of thiscollection of information, includingsuggestions for reducing this burden, toChief, Information Policy Branch. PM-223, US. Environmental ProtectionAgency. 401 M St. SW., Washington. DC20460; and to the Office of Informationand Regulatory Affairs. Office ofManagement and Budget, Washington,DC 20503, marked "Attention: DeskOfficer for EPA."

Federal Register / Vol. 54. No. 124 / Thursday. June 29,1909 / Rules and Regulations 27525

C National Drinking Water AdvisoryCouncil and Science Advisory Board

In accordance with »eclion 1412 (d)and (*) of (he Safe Drinking Water Act.EPA consulted with the Secretary andthe National Drinking Water AdvisoryCouncil and requested comments fromthe Science Advisory Board in thecourse of developing these MCI-Gs andNPDWRs.

VIII. References

Aim-Tic*n Public Health Association.Standard Melbodf for the Examination ofWtler end Wastewster (16th ed.J. APHA.Washington. DC 1085.

American Water Worki Association.Government Affairs Office Surface WaterTreatment Rule Evaluation Project FinalReport Dec. 1967.

Association of Slate Drinking WaterAdministrators. Survey to Support Analysisof the Impact* of Proposed RegulationsConcerning Filtration and Disinfection ofPublic Drinking Water Supplies. Report forU-S. EPA. September. 1986.

Eider. H, and Ifoigne. I. Determination ofOxone In Water by the Indigo Method ASubmitted Standard Method. OxoneScience and Engineering. 4:180-178.Pergsmon Press Ltd. 1982.

Bellamy. Wn Kendricks. D. and Logsdon. C.Stow Sand Filtration: Influences ofSelected Process Variables. JournalAmerican Water Works Association. Vol.77. p. 62, Dec, lOeSa.

Bellamy. W. Silvennan, C. Hendrleks. D.and Logsdon, C. Removing Ciardio Cystswith Slow Sand Filtration. JournalAmerican Water Works Association. VoL77. p. 52. Feb, 196Sb.

dark. R.M.. Read. E.J. and Hoff,J.CInactlvatlon of Ciardio lamblie byChlorine: A Mathematical and StatisticalAnalysis. Accepted for publication by theJournal of Environmental Engineering.EPA/OOO/X-67/149. Cincinnati OH. 1087.

Clark. R.M, Regli. S. and Black. DJV.fnaclivation of Giardio lomhlio by FreeChlorine: A Mathematiotl ModelPresented si AWWA Water QualityTechnology Conference. Si. I/ml*. Nov. 1$.1M6.

Craun. C.F. Health Aspects of Surface WaterSupplies. Presented at PreconfsrenceSeminar. Pacific Northwest Section.American Water Works Association.Bellevua. WA. May 6.10V.

Craun. Cf. Surface Water Supptlee andHealth. Journal of America* Water WorksAssociation. 803.40-62. February. 1066.

Craun. Cf. Memo to OfTice of DrinkingWater. USE?A. Feb. 6.106>.

Harrington. W.A, Krvpnick. A-|, andSpofford. W.O. Jr. The Benenta ofPreventing an Outbreak of Giordiosit Dueto Drinking Water Contamination. (DraftFinal Report.) Resour*s for the Future.1810 P Street NW,' ashlngton. DC.

. Scplembet. IMS,llauschlld. A-F. and Bryan, F. Estimate of

Cases of Food and Waterbome Illness InCanada and the United Stales. Journal ofFood Protection 43:435-440. 1980,

Hitiler. C P. Analysis of Municipal WaterSamples for Cysts of Giardio. Reportprepared f»r Office of Drinking Water. U.S.EPA. jHnuory. 1B87a.

Hiblcr. C P.. Mnncock. CM.. Pergcr. L.M..Wegnn. J.C.. and Swabby. K.DInaclivKtion of Giordia Cysts with Chlorine•1 O.S "C to 5.0 *C American Water WorksResearch Foundation. 19B7b.

I loff. |.C. Innctivation of Microblal Agents byChemical Disinfectants. Drinking WaterResearch Development. Office of Researchand Development. U.S. EPA. Cincinnati.OH. 1966.

Hoff. J.C. Rice. E.W. and Sehaeffer. 111. F.W.Comparison of Animal Infectivity andExcystHtion as Measures of Giordia muritCyst Inactivstion by Chlorine. Applied andEnvironmental Microbiology. VoL SO, pp.1115-1117.1965.

Hopkins. R S., Karlin. R.J.. Cespard. CJJ- andSprades. R. Gastroenteritis: Case Study ofa Colorado Outbreak. Journal AmericanWater Works Association. 78:1:40-44.[onuary. 19110.

Jsrroll. E.L.. Binghem. AJ). and Meyer. S-A.Effect of Chlorine on Giordio lamblio CyntViability- Applied and EnvironmentalMicrobiology. Vol. 41. pp. 483-487. Feb.1981.

Leahy. J.G. Inoctivation of Gtardia muritCysts by Chlorine and Chlorine Dioxide.MS Thesis. Ohio Stale University. Dept ofCivil Engineering. 1965.

Leahy. J.C. Rubin. I.], and SprouL O.T.Inaciivation of Giordio murit cysts by FreeChlorine. Applied and EnvironmentalMicrobiology. VoL 83. No. 7. pp. 1448-1453.July. 1967.

LeChcvalier. M.. Evans. T. and Seldler. R.Effect of Turbidity on ChlorinationEfficiency and Bacterial Persistence inDrinking Water. Journal Appl. Envir.Microbiology. 42:159-167. 1061.

Logsdon. OS.. Thurman. V.C. Frindt. E.S. andSioecker. |.C. Evaluating Sedimentationand Various Filter Media for Removal ofC/omVo Cysts and Cyst Models. Journal ofthe American Water Works Association.Vol. 77. pp. 61-«6. Feb.. 196S.

Logsdon. C £ Comparison of Some FiltrationProcesses Appropriate for Giordio CystRemoval. In: Wallace. P.M. and Hammond.B.R. (eds). Advances In Giardio Research.Calgary- Canada. University of Calgary

F .MarkwelL DJX. and Shortridge. ICF. Possible

Watcrhonw Transmission andMaintenance of Influenza Viruses inDomestic Ducks. Applied andEnvironmental Microbiology. Vol. 43. pp.110-116. Jan. 1081.

Rao V.C. Svmoas. J.M. Ung. A- Wang. P,Metcatl. T.C. Hoff. J.C. and Melnlck, J.URemoval of Hepatitis A Vires and ^Rota virus in Drinking Water TreatmentJournal of the American Water WorksAssociation. Vol. 60. pp. 59-67. Feb. 10*0.

Regli. S. US. EPA Disinfection Regulations.Presented at AWWA Seminar Proceedings:Assurance of Adequate Disinfection, or CTor Not CT. Kansas City. Missouri pp. 1-7.June 14. 1«6?.

Regli. &. A»irthara|ah. A. Borup. B_ Hlbler.C, Hoff. T and Tobln. R. Panel Discussionon lmplk*i«oni of Regulatory Changes for

Water Treatment in the United S(n<r« InWnllncc. P.M. and Hammond. n.H (nts)Advances in Giartiio Research. CiilicurCnniidi. University of Ca\gnry Prr**.

Rice. E.W, Hoff. J.C and Schatfcr III. f wInaciivation or Giardio Cysts by CltlormrApplied and Environmental Mirroliioln^vVol. 43. pp. 250-251. Jan.. 19B2.

Rose. J.B. Ctyptosperidium in Wwicr Ri<cl, ,,fProtozoan Watcrborne TransmissionReport prepared for the Officr of Nrinkmj:Water. U5. EPA. Summer. 1988.

Rubin. A.J. Factors Affecting the Inactivntiunof Giordio. Cysts by Monochlornmine m«fComparison with Other Disinfectants.EPA/600/9-68/004. Water EngineorincResearch Laboratory. Qnclnrwti. Oil.March. 1968a.

Rubin. A.J. CT Products for the tnnctiviumnof Giordia Cysts by Chlorine. Chlornminr.Iodine and Chlorine Dioxide. Submitted forpublication in Journal of American WntrrWorks Association, December. 196Mv

Rubin. A.J. (ntemat Report of Progress. KI'AProject CR612236. June. 1906c

Science Advisory Board. Report El IC-WMCtU.S. EPA. Mar. 9.1068.

Sobsey. M.D. Detection and ChlorineDisinfection of Hepatitis A in Water. CR-813-024. EPA Quarterly Report Dec. in*

U.S Environmental Protection Agency. OfTW*of Drinking Water. Criteria and StandardsDivision. Criteria Document forTurbuliu.1964.

US. Environmental Protection Agency. OfTircof Drinking Weter. Criteria and StnixUnJnDivision. Criteria Document forHeierotrophic Plate Count 1084.

U.S. Environmental Protection Agency. Officeof Drinking Water. Criteria and Standard*Division. Criteria Document for Ltyionel t.I985a.

U.S. Environmental Protection Ajtmcy. OfTtiYof Drinking Water. Criteria and SlandnrUsDivision. Criteria Document for Vlntses.108SD.

US- Envtronmenlal Protection Agency. OfTirrof Drinking Water. Criteria and SiandoMnDivision, Health Advisory for LtgioafHaI967a.

US. Environmental Protection Agency.of Drinking Water. CriteriaDivision. Draft Guidance Manual forCompliance With the Surface WaterTreatment Requirements for Public Wntt-rSystems. 1067b.

US. Environmental Protection Agency. OfTV»of Drinking Water. Regulator)- ImpactAnalysis: Benefits and Costs of (TttpueettSurface Water Treatment Requirementsand ToUl CoUform Rule. 1697c.

VS. Environmental Protection Agency, Oflurof Ground Water Protection. Cuidclinr* fvcApplicants for Slate Wellhead ProtectionProgram Assistance Funds Under the S«frDrinking Water Act 19674

VS. Environmental Protection Agency. Offlwof Drinking Water. Criteria and Siand«rdsDivision. Evaluation of Specific Criteria o.'the Surface Water Treatment Rule. 1068«

U.S. Environmental Protection Agency. OffW*of Drinking Water. Criteria and Standard*Division. Technologies and Costs for theRemoval of Microbiological Conl»mln«nt«from Potable Water Supplies. lOHBli.

27S26 Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations

U.S. £nTironmenul Protection Agency. Offic*of Drinking Water. Addendum 10Regulatory Impact Analysis: Benefit! andCo*u of Proposed Suffice WaterTreatment Rule and Total Coliform Rule.1889a.

U.S. Environmental Protection Agency. Officeof Drinking Water. Criteria and Standard*Division. Response to Public Comment* onProposed Surface Water TreatmentRequirement*. I969b.

XVickramanayake. CJL Rubin. A.L, andSprouL O.J. Effects of Ozone and StorageTemperature on Giardia Cysts. JournalAmerican Water Works Association. VoL77. pp. 74-77. Feb, 1985.

List of Subjects in 40 CFR Parts 141 and142

Chemicals. Incorporation byreference. Intergovernmental relations.Reporting and recordkeepingrequirements. Water supply.Administrative practice and procedure.

Dated: June 19,1988.

William K. Reilly.Admuuttntor.

For the reasons set forth in thepreamble. Tide 40 of the Code of FederalRegulations is amended as follows;

PART 141—NATIONAL PRIMARYDRINKING WATER REGULATIONS

1. The authority for Purl 141 is revisedto read as follows:

Authority: 42 U.S.C MOf. WJg-1. MQg-t300g-3.300t-i 9001-S. MQg-e. 300|-4. and300J-9.

2. In f 141.2, the following definitionsare added and arranged alphabeticallyto read a« follows:

$141.2 DefinKlona.• • • • •

"Coagulation" means a process usingcoagulant chemicals and mixing bywhich colloidal and suspendedmaterials are destabilized andagglomerated into floe*.

"Conventional filtration treatment"means a series of processes includingcoagulation, flocculstion, sedimentation,and filtration resulting in substantialpaniculate removal• • • • •

"CT" or "CTcalc" is the product of"residual disinfectant concentration" (C)in mg/1 determined before or at the firstcustomer, and the corresponding"disinfectant contact time" (TJ inminutes. La, "C" x "T". If t public watersystem applies disinfectants at morethan one point prior to the firstcustomer, it must determine the CT ofeach disinfectant sequence before or atthe first customer to determine the totalpercent inactivation or "totalinactivation ratio." In determining thetotal inactivation ratio, the public water

system must determine the residualdisinfectant concentration of eachdisinfection sequence andcorresponding contact time before anysubsequent disinfection applicationpoint(s). "CIW is the CT valuerequired for 99.9 percent (3-log)inactivation of Giardia lamblia cysts.CTw« for a variety of disinfectants andconditions appear in Tables 1.1-1.6, 2.1,and 3.1 of 1 141.74(b){3).

CTcalc

is the inactivation ratio. The sum of theinactivation ratios, or total Inactivationratio shown as

(CTcalc)

ICT.,)

is calculated by adding together theinactivation ratio for each disinfectionsequence. A total inactivation ratioequal to or greater than 1.0 is assumedto provide a 3-log inaclivation ofGiardia lamblia cysts.

"Oiatomaceous earth filtration"means a process resulting in substantialpaniculate removal in which (1) aprecoat cake of diatomaceous earthfilter media is deposited on a supportmembrane* (septum), and (2) while thewater is filtered by passing through thacake on tha septum, additional filtermedia known as body feed iscontinuously added to the feed water tomaintain the permeability of the filtercake.

"Direct filtration" means a series ofprocesses including coagulation andfiltration but excluding sedimentationresulting in substantial paniculateremoval.• • • • •

"Disinfectant contact time" (T" in CTcalculations) means the time In minutesthat it takes for water to move from thepoint of disinfectant application or theprevious point of disinfectant residualmeasurement to a point before or at thepoint where residual disinfectantconcentration ("C") Is measured. Whereonly on* "C" la measured. T' is thetime In minutes that it takes for water tomove from the point of disinfectantapplication to a point before or at whereresidual disinfectant concentration ("C")is measured. Where more than one "C'is measured T" la (a) for the firstmeasurement of "C', the time in minutesthat It takes for water to movt from thefirst or only point of disinfectantapplication to a point before or at the *point where the first "C" is measuredand (b) for subsequent measurements of"C". the time in minutes that it lakes forwater to move from the previous "C"

measurement point to the "C*measurement point for which theparticular "T" is being calculatedDisinfectant contact time in pipelinesmust be calculated based on "plug flow"by dividing the internal volume of thepipe by the maximum hourly flow ratethrough that pipe. Disinfectant contacttime within mixing basins and storagereservoirs must be determined by tracerstudies or an equivalent demonstration.

"Disinfection" means a process whichinactivates pathogenic organisms inwater by chemical oxldants orequivalent agents.• • • • •

"Filtration" means a process forremoving paniculate matter from waterby passage through porous media.

"Flocculation" means a process toenhance agglomeration or collection ofsmaller doc particles into larger, moweasily settleable particles through gentlestirring by hydraulic or mechanicalmeans.

"Ground water under the directinfluence of surface water" means anywater beneath the surface of the groundwith (1J significant occurrence of insectsor other macroorgaoiama, algae, orlarge-diameter pathogens such aaGiardia lamblia, or (2) significant andrelatively rapid shifts in watercharacteristic* such aa turbidity,tempera rare, conductivity, or pH whichclosely correlate to climatological orsurfsce water conditions. Directinfluence must be determined forindividual sources in accordance withcriteria established by the Slate. TheSlate determination of direct Influencemay be based on lite-specificmeasurements of water quality and/ordocumentation of well constructioncharacteristics and geology with fieldevaluation.• • • • •

"Legionetia" means a genus ofbacteria, some specie* of which havecaused • type of pneumonic called 'Legionnaires Disease.

"Point of disinfectant application" i*the point where the disinfectant isapplied and water downstream of thatpoint la not subject To recontamlnattonby surface water runoff.

"Residual disinfectant concentration"("C' in CT calculations) means theconcentration of disinfectant measuredIn mg/l in a representative sample ofwater.• • • • 4

"Sedimentation" means a process forremoval of solids before filtration bygravity or separation.

"Stow sand filtration" means aprocess involving passage of raw waler

Federal Register / Vol. 54. No. 124 / Thursday. June 29.19B9 / Rules and Regulations 27527

through a bed of *and at low velocity(generally lea* than 0.4 m/h) resulting inlubstantial paniculate removal byphysical and biological mechanisms.• • • • •

"Surface water** means all water .which is open to the atmosphere andsubject to surface runoff.• • • • •

"Watcrborne disease outbreak"means the significant occurrence ofacute Infectious illness.epldemiologically associated with theingcstlon of water 'from a public watersystem which Is deficient In treatment.as determined by the appropriate localor State agency.

"Virus" means a virus of fecal originwhich is Infectious to human* bywaterbome transmission.

3. Section 141.13 1* amended byadding introductory text to read atfollow*:f 141.13 Mailmum contaminant tevela forlurbMlty.

The requirements In this section applyto unfiltered systems until December 30,1991. unless the Slate ha* determinedprior to that date, in writing pursuant to1 14l2(b)(7)(C)(ill). that filtration larequired. The requirements in thissection apply to filtered systems untilJune 29. 1993. The requirement* in this•ection apply to unfiltered system* thatthe Slate ha* determined, in writingpursuant to 1 1412(b)(7)(Q(lll). mu«tinstall filtration, until June 29, 1993, oruntil filtration 1* installed, whichever islater.• • • # •

4. Section 141.22 it amended byadding Introductory text to read asfollow*:

1141.22 Turbidity aampflng and analytical

The requirement* in this section applyto unfiltered systems until December30.1991. unlet* the Sttta hat determinedprior to that date, (n writing pursuant to•ection 14l2(b)(7)(iil). (bat nitration larequired. The requirement* to thissection apply to fillrrad tyatent anttlJune 29, 1993. The requirements In thi*section apply to unfiltered *y*tem* thatthe State hat determined. In writingpursuant to section 1412(b)(7)(Q(iii),must install filtration, until June 29. 1993.or until filtration Is Installed. whicheverI* later.• « « • •

S. Section 141.32 1* amended byadding new paragraph* (a)(l)(Ui)(D) and(e)(10) to read a* follow*:

§14147 PuMIc notification.

(a) ' ' *( I ) ' * '(iii) ' * *(D) Occurrence of a waterbome

disease outbreak, as defined in 1 141.2,in an unfiilered system subject to therequirement* of Subpart H of thi* part.after December 30. 1991 (teef 1

(e) • • •(10) Microbiological contaminants

(for use when there i* a violation of thetreatment technique requirement* forfiltration and disinfection in Subpart H-of thi* part). The United State*Environmental Protection Agency (EPA)lets drinking water atandard* and ha*determined that the presence ofmicrobiological contaminant* are ahealth concern at certain level* ofexposure. If water 1* inadequatelytreated, microbiological contaminants inthat water may cause disease. Diseasesymptoms may Include diarrhea. .cramps, nausea, and poJtibly Jaundice.and any atsociated headaches andfatigue. These symptom*, however, arenot fuit associated with disease-causingorganism* in drinking water, but altomay be caused by a number of factor*other than your drinking water. EPA ha*set enforceable requirement* for treatingdrinking water to reduce the riak ofthese adverse health effect*. Treatmentsuch as filtering and disinfecting thewater remove* or destroytmicrobiological contaminant*. Drinkingwater which i* treated to meet EPArequirement* 1* associated with little tonone of this risk and thould beconsidered safe.

6. In Part 141, a new 1 141 52 It addedto read a* follow*:

{141.S2 Maximum contaminant tovc4floaia for mlcrobtotofllcaJ contaminant*.

MCLG* for the followingcontaminant* are a* indicated:

WUB*

MOO

7. A new Subpart H i* added to reada* follows: "Subpart M—nitration and Dialnfectton

141.70 General requirement*.141.71 Criteria for avoiding; filtratloa.141.72 Oisinfecttoa.141.73 Filtration.141.74 Analytical and nonitorlna

requirements..-• i / j Reporting and recorfflcteping

requirement*.

Subpart H—Filtration and Disinfection

} 141.70 Central requirements.(a) The requirements of this Subparl H

constitute national primary drinkingwater regulations. These regulationsestablish criteria under which filtrationis required as a treatment technique forpublic water systems supplied by asurface water source and public watersystems supplied by a ground watersource under the direct influence ofsurface water. In addition, theseregulations establish treatmenttechnique requirement* in lieu ofmaximum contaminant level* for thefollowing contaminant*: Ciardialamblia, viruses, heterotrophic platecount bacteria, LegioneHa, and turbidity.Each public water system with a surfacewater source or a ground water sourceunder the direct Influence of surfacewater must provide treatment of thatsource water that complies with thesetreatment technique requirements. Thetreatment technique requirement*consist of installing and properlyoperating water treatment processeswhich reliably achieve:

(1) At least 99.9 percent (3-log)removal and/or inactivation of Ciardialamblia cysts between a point where theraw water is not subject torecontamination by surface water runoffand a point downstream before or at thefirst customer and

(2) At least 99.99 percent (4-log)removal and/or inactivation of virusesbetween a point where the raw water isnot subject to recontamination bysurface water runoff and a pointdownstream before or at the firstcustomer.

(b) A public water system using asurface water source or a ground watersource under the direct influence ofsurface water la considered to be incompliance with the requirement* ofparagraph [a] of thi* *ection If:

(1) It me«U the requirement* foravoiding filtration (n 1141.71 and thedisinfection requirement* in 1141J2(a);or

(2) It meets the filtration requirementsin 1141.73 and the disinfectionrequirements In 1141.72(b).

(c) Each public water system using asurface water source or a ground watersource under the direct influence ofsurface water must be operated byqualified personnel who meet therequirements specified by the State.

1141.71 Criteria for avoiding fRtratUxvA public water system that uses a

surface water source must meet all ofthe conditions of paragraphs (a) and (b)of this section, and is subject to

27528 Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulation!

paragraph (c] of (his section, beginningDecember 30.1991, unles* the State hasdetermine.', in w-iting pursuant to{ 1412(b)(rflC}fui). that filtration isrequired. A public water system thatuses a ground water source under thedirect influence of surface water mustmeet all of the conditions of paragraphs(a) and (b) of this section and is subjectto paragraph (c) of this section,beginning 18 months after the Statedetermines that it is under the directinfluence of surface water, or December30,1991, whichever is later, unless theState has determined, in writingpursuant to f 1412(b)(7)(C)(iii). thatfiltration is required, (f the Statedetermines in writing pursuant to{ 1412(b)(7MQ(iii) before December 30,1991, that filtration is required, thesystem must have installed filtrationand meet the criteria for filtered systemsspecified in if 14172(bJ and 141.73 byJune 29.1993. Within 18 months of thefailure of a system using surface wateror a ground water source under thedirect influence of surface water to meetany one of the requirements ofparagraphs (a) and (b] of this section orafter June 29,19S3. whichever is later,the system must have installed filtrationand meet the criteria for filtered systemsspecified in Ji 141J2(b) and 14173.

(a) Source water quality conditions.(I] The fecal coliform concentrationmust be equal to or less than 20/100 ml.or the total coliform concentration mustbe equal to or less than 100/100 ml(measured as specified in 1141.74 (a)(l)and (2] and (b)(l)), in representativesamples of the source waterimmediately prior to the first or onlypoint of disinfectant application in atleast 90 percent of the measurementsmade for the 6 previous months that thesystem served water to the public on anongoing basis. If a system measuresboth fecal and total coliforms. the fecalcoliform criterion, but not the totalcoliform criterion, in this paragraphmust be met.

(2) The turbidity level cannot exceed 9NTU (measured as specified In f 141.74(a)(4) and (b)(2)) in representativesamples of the source waterimmediately prior to the first or onlypoint of disinfectant application unless:(i) the State determines that any suchevent was caused by circumstances thatwere unusual and unpredictable; and (ii)as a result of any such event, there havenot been more than two events in thepast 12 months the system served waterto the public, or more than five events Inthe past 120 months the system servedwater to the public, in which theturbidity level exceeded 5 NTU. An"event" is a series of consecutive days

during which at Icjsl one turbidi tymeasurement each day exceeds 5 NTU.

(b) Site-specific conditions. (l)(i) Thepublic water system must meet therequirements of 1141.72(a)(l) at least 11of the 12 previous months that thesystem served water to the public, on anongoing basis, unless the system fails tomeet the requirements during 2 of the 12previous months that the system servedwater to the public, and the Staledetermines that at least one of thesefailures was caused by circumstancesthat were unusual and unpredictable.

(II) The public water system mostmeet the requirements of 1141.72(a)(2)at all times the system serves water tothe public

(iii) The public water system mustmeet the requirements of f141.72(a)(3)at all times the system serves water tothe public unless the State determinesthat any such failure was caused bycircumstances that were unusual andunpredictable.

(iv) The public water system mustmeet the requirements off 141.72(a)(4)on an ongoing basis unless the Statedetermines that failure to meet theserequirements was not caused by adeficiency In treatment of the sourcewater.

(2) The public water system mustmaintain a watershed control programwhich minimizes the potential forcontamination by Giardia lamblia cystsand viruses in the source water. TheState must determine whether thewatershed control program Is adequateto meet this goal. The adequacy of aprogram to limit potential contaminationby Giardia lamblia cysts and virusesmust be based on: thecomprehensiveness of the watershedreview, the effectiveness of the system'sprogram to monitor and controldetrimental activities occurring in thewatershed; and the ex lent to which thewater system has maximized landownership and/or controlled land usewithin the watershed At a minimum,(he watershed control program must:

(i) Characterize the watershedhydrology and land ownership;

(ii) Identify watershed characteristicsand activities which may have anadverse effect on source water quality:and

(iii) Monitor the occurrence ofactivities which may have an adverseeffect on source water quality.

The public water system mustdemonstrate through ownership and/orwritlen agreements with landownerswithin the watershed that It can controlall human activities which may have anadverse impact on the microbiologicalquality of the source water. The public

water system must submit an annualreport to the Slate that identifies anyspecial concerns about the watershedand how they are being handled;describes activities in the watershedthat affect water quality; and projectswhat adverse activities are expected tooccur in the future and describes howthe public water system expects toaddress them. For systems using aground water source under the directinfluence of surface water, an approvedwellhead protection program developedwider section 1428 of the Safe DrinkingWater Act may be used, if the Slatedeems it appropriate, to meet theserequirements.

(3) The public water system must besubject to an annual on-site inspectionto assess the watershed control programand disinfection treatment process.Either the State or a party approved bythe State must conduct the on-slteinspection. The inspection must beconducted by competent individual*such as sanitary and civil engineers,sanitarians, or technicians who haveexperience end knowledge about theoperation and maintenance of a publicwater system, and who have a soundunderstanding uf public healthprinciples and waterborne diseases. Areport of the on-site inspectionsummarizing all findings must beprepared every year. The on-slteinspection must indicate to the Stale'ssatisfaction diat (he watershed controlprogram and disinfection treatmentprocess are adequately designed andmaintained. The on-site inspection mustinclude:

(!) A review of the effectiveness of thewatershed control program;

(ii) A review of the physical conditionof the source intake and how well II isprotected;

(iii) A review of the system'sequipment maintenance program toensure there is low probability forfailure of the disinfection process;

(iv) Aa inspection of the disinfectionequipment for physical deterioration;

(v) A review of operating procedures;(vi) A review of data record* to

ensure that all required tests are beingconducted and recorded anddisinfection is effectively practiced: and

. (vii) Identification of anyimprovements which are needed in theequipment, system maintenance andoperation, or data collection.

(4) The public water system must nothave been identified as a source of awalerbome disease outbreak, or if it hasbeen so identified, the system must havebeen modified sufficiently to preventanother such occurrence, as determinedby the State.

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations 27529

(5) The public water system rr. 'comply with the maximum coma.-;, .antlevel (MCL) for total coliformt ir.{141.63 at least 11 months of (he .1previous months that (he system rfrvedwater to the public, on an ongc:-.,. -,asis,unless the State determines that fa lureto meet this requirement was not causedby a deficiency in treatment of thesource water.

(0) The public water system mintcomply with the requirements fortrihalomethanes In If 141.12 and 141.30.

(c) Treatment technique violation*. (1)A system that fi) fails to meet any one ofthe criteria In paragraphs (a) and (b) ofthis section and/or which the State hasdetermined that filtration Is required. Inwriting pursuant to f 1412(b)(7)(C)(iii).and (ii) fails to install filtration by thedate specified In the Introductoryparagraph of this section is In violationof a treatment technique requirement

(2) A system that has not installedfiltration (s In violation of t treatmenttechnique requirement If:

(1) The turbidity level (measured asspecified In 1141.74(a)(4) and (b)[2)) in arepresentative sample of the sourcewater immediately prior to the first oronly point of disinfection applicationexceeds 5 NTU: or

(il) The system Is Identified as •source of a waterbome diseaseoutbreak.

1141.72 Disinfection.A public water system that uses •

surface water source and does notprovide filtration treatment mustprovide the disinfection treatmentspecified in paragraph (a) of this sectionbeginning December 30.1991. unless theStale determines that filtration Isrequired in writing pursuant to 11412(b)(7)(CKtii). A public water system thatuses a ground water source under thedirect influence of surface water anddoes not provide filtration treatmentmust provide disinfection treatmentspecified in paragraph (•) of this sectionbeginning December 30,1991. or 18months after the Slat* tfttcrminM thatthe ground water souros b under thtInfluence of surfac* wctar. whichever islater, unless the Slates** determinedthat filtration Is required in writingpursuant to 11412{bK7HC)(iii). II "»e .Stale has determined that filtration isrequired, the system must comply withany Interim disinfection requirementsthe Slate deems necessary beforefiltration is installed. A system that usesa surface water source that providesfiltration treatment must provide thedisinfection treatment specified Inparagraph (b) of this section beginnngJune 29,1993. or beginning whenfiltration is installed, whichever Is later!

A system that uses a ground watersource under the direct influence ofsurface water and provides filtrationtreatment must provide disinfectiontreatment as specified in paragraph (b)of this section by June 29,1993. orbeginning when filtration is installed,whichever is later. Failure to meet anyrequirement of this section after theapplicable date specified in thisintroductory paragraph is a treatmenttechnique violation.

(a) Disinfection requirements forpublic water systemt that do notprovide filtration. Each public watersystem that does not provide filtrationtreatment must provide disinfectiontreatment as follows:

(1) The disinfection treatment must besufficient to ensure at least 99.9 percent(3-log) inactivation of Ciardia lambliacysts and 99.99 percent (4-log)inactivation of viruses, every day thesystem serves water to the public,except any one day each month. Eachday a system serves water to (he public,the public water system must calculatethe CT valuefs) from the system'streatment parameters, using theprocedure specified in 1141.74(b)(3). anddetermine whether this valuefs] issufficient to achieve the specifiedinactivation rates for Ciardia lambliacysU and viruses. If a system uses adisinfectant other than chlorine, thesystem may demonstrate to the State,through the use of a Stale-approvedprotocol for on-site disinfectionchallenge studies or other informationsatisfactory to the Slate, that CTM«values other than those specified inTables 2.1 and 3.1 In 1141.74(b)(3) orother operational parameters anadequate to demonstrate that the systemIs achieving minimum Inactivation ratesrequired by paragraph (a)(l) of thissection.

(2) The disinfection system must haveeither (i) redundant components,including an auxiliary power supplywith automatic start-up and alarm toensure that disinfectant application ismaintained continuously while water Isbeing delivered to the distributionsystem, or (ii] automatic shut-off ofdelivery of water to the distributionsystem whenever there is less than 0.2mg/l of residual disinfectant "concentration in the water. If the Statedetermines that automatic shut-offwould cause unreasonable risk to healthor int- rfcre vith fire protection, thesysie i must comply with paragraph(a)(2)(i) of this section.

(3) The residual disinfectantconcentration in the water entering thedistribution system, measured asspecified in il41.74(a)(S) and (b)(5).

cannot be less than 0-2 mg/l (or morethan 4 hours.

(4)(i) The residual disinfectantconcentration in the distribution system.measured as toul chlorine, combinedchlorine, or cnlorine dioxide, asspecified in f I41.74(a)(5) and (b)(6),cannot be undetectable in more than 5percent of the samples each month, forany two consecutive months that thesystem serves water to the public.Water in the distribution system with aheterotrophic bacteris concentrationless than or equal to SOO/ml. measuredas heterotrophic plate count (HPC) asspecified in | I41.74(a)(3). is deemed tohave a detectable disinfectant residualfor purposes of determining compliancewith this requirement Thus, the value"V" in the following formula cannotexceed 5 percent in one month, for anytwo consecutive months.

c+d+e

• +bXlOO

where-a - number of instance* where the residuul

disinfectant conceti(ration i* measured:b» number of instance* where the rcxidunl

disinfectant concentration t* notmeasured but helerotrophic bacteriaplate count (HPC) Is measured:

c-number of Instances where the rcslduuldisinfectant concentration is measuredbut not detected and no HPC I*measured:

d-number of instances where the residualdisinfectant concentration i* measuredbut not defected and where tht UPC Is> SOO/ml: and

e« number of Instances where the residualdisinfectant concentration I* notmeasured and HPC I* >SOO/ml.

(ii] If the Slate determines, based onsite-specific considerations, that asystem has no means for having asample transported and analyzed forHPC by a certified laboratory under the-requisite lime and temperatureconditions specified by i 141.74(a)(3)and that the system is providingsdequate disinfection in the distributionsystem, the requirements of paragraph(s](4)(i) of this section do not apply tothat system.

(b] Disinfection requirements forpublic water systems which providefiltration. Each public water system thiiiprovides filtration treatment mustprovide disinfection treatment usfollows.

(1) The disinfection treatment must In-sufficient lo ensure that the lolultreatment processes of that systemachieve at least 99.9 percent (3-lop)inaclivalion and/or removal of CiortfinIcniblia cysts and at least 99.99 percent

27530 Federal Register f Vol. 54. No: 124 / Thursday. June 29.1909 / Rules" and Regulations

(4-logj inactivaticn and/or removal ofviruses, as determined by the State.

(2) The rrsidual disinfectantconcentration in (he water entering thedistribution system, measured asspecified in f 141.74 (»)(5) and (c)(2),cjnnot be less than 0.2 mg/1 for morethan 4 hours.

(3](i) The residual disinfectantconcentration in the distribution system,measured as total chlorine, combinedchlorine, or chlorine dioxide, asspecified in 1141.74 U)(5) and (c)(3).cannot be undetectabss in more than 5percent of the samples each month, forany two consecutive months that the .system secves water to the public.Water in the distribution system with ahcterotrophic bacteria concentrationless than or equal to 500/mL measuredas hcterotrophic plate count (11PC) asspecified in 1141.74(8^3). is deemed tohave a detectable disinfectant residualfor purposes of determining compliancewith this requirement Thus, the value" V in the following formula cannotexceed S percent in one month, for anytwo consecutive months.

V-c+d+e

a+bxtoo

where• - number of instance* where lh« residue)

disinfectant concentration Is mo«*ured;b«number of instance! when lh« residual

disinfectant concentration is notmeasured but hcterotrophic bacteriapUlt count (HPC) is measured-

c m number of Instances where the rciidusldisinfectant concentration Is measuredbut not detected and no HPC Ismeasured;

d - number ef irsttnats where, no midualdisinfectant concentration is detectedand whers the HPC is >SOO/mt and

«» number ef instances where the residualdisinfectant concentration Is notmeasured and HFC Is >SOO/mL

(ii) If (he State determines, based onsite-specific considerations, that asystem has no means for having asample transported and analyzed forUPC by • certified laboratory under therequisite time and temperatureconditions specified in 1141.74(a)(3) andthat (he system is providing adequatedisinfection in the distribution system,(he requirements of paragraph (b](3)(i]of this section do not apply.

{141.73 nitration.A public water system that uses a

surface water source or a ground watersource under the direct influence ofsurface water, and does not meet all of(he criteria in 1141.71 (a) and (b) foravoiding nitration, must providetreatment consisting of both

disinfection, as specified in i 141.72(b), 'and filtration treatment which complieswith the requirements of paragraph (a),(b). (c). (d), or (e) of this section by June29,1993. or within 18 months of thefailure to meet any one of the criteria foravoiding filtration in J 141.71 (a) and {b).whichever is later. Failure to meet anyrequirement of this section after the datespecified in this introductory paragraphIs a'treatment technique violation.

(a) Conventional filtration treatmentor dinct filtration. (1) For systems usingconventional nitration or directfiltration, the turbidity level ofrepresentative samples of a system'sfiltered water must be less than or equalto 0.5 MTU in at least 95 percent of themeasurements taken each month,measured as specified in i 141.74 (a)(4)and (c)(l). except that if the Statedetermines that the system is capable ofachieving at least 99.9 percent removaland/or inactivation of Giardia lambliacysts at some turbidity, level higher than04 MTU in at least 95 percent of themeasurements taken each month, theState may substitute this higherturbidity limit for that system. However,in no case may the State approve aturbidity limit that allows more than 1NTU in more than S percent of thesamples taken each month, measured asspecified In 1141.74 (a)(4) and (c)(l).

(2) The turbidity level ofrepresentative samples of a system'sfiltered water must at no time exceed 5NTU, measured as specified hi f 141.74(a)(4J and (c)(l).

(b) Slow land filtration. (I) Forsystems using slow sand filtration, theturbidity level of representative sample*of a system's filtered water must be lessthan or equtl to 1 NTU in at least 85percent of the measurements taken eachmonth, measured as specified in 1141.74(a)(4) and (c)(l). except that if the Statedetermines there is no significantInterference with disinfection at a higherturbidity level the Slate may substitutethis higher turbidity limit for thatsystem.

(2) The turbidity level ofrepresentative samples of a system'sfiltered water must at no time exceed 5NTU, measured as specified In i 141.74(a)(4Jand(c)(l).

(c) Diatomoceotu earth filtration. (IjFor systems using diatomaceous earthfiltration, the turbidity level ofrepresentative samples of a system'sfiltered water must be less than or equalto 1 NTU In it least 95 percent of themeasurements taken each month,measured as specified in 1141.74 (a)(4)and (c)(l).

(2) The turbidity level ofrepresentative samples of a system'sfiltered water must at no time exceed 5

NTU. measured as specified in { 141.74(a)(4) and (c)(l).

(d) Other filtration technologies. Apublic water system may use a filtrationtechnology not listed in parugruphs («}-(c) of this section if it demonstrates tothe Slate, using pilot plant studies orolher means, that the alternativefiltration technology, in combinationwith disinfection treatment that meetsthe requirements of i 141 J2(b),consistently achieves 99.9 percentremoval and/or inactivaUon of Giardiotaatblia cysts and 09.99 percent removaland/or inactivation of viruses. For asystem that makes this demonstration,the requirements of paragraph (b) of thissection apply.

1141.74 Analytical and monitoringrequirements.

(a) Analytical nquirtmenla. Only theanalytical method(s) specified in thisparagraph, or otherwise approved byEPA. may bo used to demonstratecompliance with the requirements ofI i 14L7X14172. and 141.73.Measurements for pH. tempera ture.turbidity, and residual disinfectant • •

' concentrations must be conducted by aparty approved by the State.Measurements for total coliforms, fecalcoliforms, and HPC must be conductedby a laboratory certified by the State orEPA to do such analysis. Untillaboratory certification criteria aredeveloped for the analysis of HPC andfecal coliforms, any laboratory certifiedfor total coliform analysis by EPA isdeemed certified for HPC and fecalcoliform analysis. The followingprocedures shall bo performed inaccordance with the publications listedIn the follow/ng section. Thisincorporation by reference wasapproved by the Director of the FederalRegister in accordance with 5 U.S.C.K2(a) and 1CFR Part 51. Copies of themethods published In Standard Methodsfor th» Examination of WoUr aitdWostewofermay be obtained from theAmerican Public Health Association etat, 1015 Fifteenth Street. NW, ;Washington. DC 20005; copies of theMinimal Medium ONPG-MUC Methodas set forth in the article "National FieldEvaluation of a Defined SubstrateMethod for the SimultaneousEnumeration of Total Coliforms andEshtrichia cot/ from Drinking WaterComparison with the Standard MultipleTube Fermentation Method" (Edberg etal.). Applied and EnvironmentalMicrobiology. Volume 54. pp. 1595-1001.June 1988 (as amended under Erratum.Applied and EnvironmentalMicrobiology. Volume 54. p. 3197.December. 1988), may be obtained from

Federal Register / Vol. 54. No 124 / Thursday. June 29,1989 / Rules and Regulations 27531

the American Water Work* AssociationResearch Founds "on. 0086 West QulncyAvenue. Denver Colorado. 80235: andcopies of (he indigo Method as set forthin the article "Determination of Ozonein Water by the Indigo Method" (Baderand Hoigne). may be obtained fromOzone Science A Engineering. PergamonPress LlcL Fairview Park. Elms ford,New York 10523. Copies may beinspected at the U.S. EnvironmentalProtection Agency, Room EB1S, 401 MStreet. SW, Washington. DC 20460 or atthe Office of the Federal Register. 1100 LStreet NW, Room 8401. Washington.DC

(1) Feed coliform concentration—Method 908C (Fecal Coliform MPNProcedures), pp. 678-680. Method 908D(Estimation of Bacterial Density), pp.680-682. or Method 909C (Fecal ColiformMembrane Filter Procedure), pp. 896-898, as set forth ia Standard Methods forthe Examination of Water andWastewcter. 1985. American PublicHealth Association et ah. 16th edition.

(2) Total coliform concentration—Method 908A (Standard Total ColiformMultiple—Tnbe (MPN) Teats), pp. 872-87D, Method 908B (Application of Teststo Routine Examinations), pp. 876-878.Method 908D (Estimation of BacterialDensity), pp. 880-682. Method 909A(Standard Total Coliform MembraneFiller Procedure), pp. 887-694. or Method909B (Delayed—Incubation TotalColiform Procedure), pp. 894-696. as setforth In Standard Method* for theExamination of Water and Wastewater.198S. American Public HealthAssociation et aL. 16th edition: MinimalMedium ONPG-MUG Test, as vet forthIn the article "National Field Evaluationof a Defined Substrate Method for theSimultaneous Enumeration of TotalColiforms and Etcherichio colt fromDrinking Water Comparison with theStandard Multiple Tube FermentationMethod" (Edberg et al.). Applied andEnvironmental Microbiology. Volume 54.pp. 1595-1601. June 1S68 (as amendedunder Erratum. Volume H. p. 1107,December. 1988).' (NeU:Th« Minimal Medina ONVC-MUCTest Is sometimes referred lo as (haAutosntlyili Coliterl System). Systems mayu*« a Qvt-tub* leit or • ten-tab* last

(3) Heterotrophlc Plate Count-Method 907A (Pour Plate Method), pp.664-666. as set forth In StandardMethods for the Examination of Waterand Wottewater, 1985. American PublicHealth Association et aL. 16th edition.

(4) Turbidity—Method 214A(Ncphelometric Method—NephelometricTurbidity Units), pp. 134-136, as setforth In Standard Methods for theExamination of Water and Wastewater,

1985. American Public HealthAssociation et al.. 16th edition.

(5) Residual disinfectantconcentration—Residual disinfectantconcentrations for free chlorine andcombined chlorine (chloramines) mustbe measured by Method 408C(Amperometric Titralion Method), pp.305-306. Method 408D (DPD FerrousTitrimetric Method), pp. 306-309.Method 408E (DPD ColorimetricMethod), pp. 309-310. or Method 408F(Leuco Crystal Violet Method), pp. 310-313, as set forth in Standard Methods forthe Examination of Water andWastewater. 1985. American PublicHealth Association et al., 16th edition.Residual disinfectant concentrations forfree chlorine and combined chlorinemay also be measured by using DPDcolorimetric teat kits If approved by theState. Residual disinfectantconcentrations for ozone must bemeasured by the Indigo Method as setforth in Bader. H.. Hoigne. J-."Determination of Ozone in Water bythe Indigo Method; A SubmittedStandard Method"; Ozone Science andEngineering. Vol. 4, pp. 169-176,Pergamon Press Ltd., 1962. or automatedmethods which are calibrated Inreference to the results obtained by theIndigo Method on i regular basis, ifapproved by the State.

Nolr Thit method will be published In the17U» tdilioa of Standard Method* for theExamination of Water and Waitewoter,American Public Health Association et aUthe lodomelrlc Method in the 16th editionnay not b« used.

Residual disinfectant concentrationsfor chlorine dioxide must be measuredby Method 410B (Amperometric Method)or Method 410C (DPD Method), pp. 322-324, as set forth in Standard Method* forthe Examination of Water endWastewater. 1965, American PublicHealth Association at aL. 16th edition,

(6) Temperature—Method 212(Temperature), pp. 126-127. as set forthin Standard Methods for theExamination of Water and Wastewater.1965. American Public HealthAssociation it aU 16th edition.

(7) pH—Method 423 (pH Value), pp.429-437. as set forth in StandardMethods for the Examination of Waterand Wastewater. 1965. American PublicHealth Association. 16th edition.

(b) Monitoring requirements forsystems that do not provide filtration. Apublic water system that uses a surfacewater source and does n<A providefiltration trealmen. must beginmonitoring, as specified in thisparagraph (b). beginning December 31,1990. unless the Stale has determinedthat nitration is required in writing

pursuant to i 14l2(b)(7)(C)(iii), in whichcase the State may specify alternativemonitoring requirements, as appropriate.until filtration is in place. A public watersystem that uses * ground water sourceunder the direct influence of surfacewater and does not provide filtrationtreatment must begin monitoring asspecified in this paragraph (b) beginningDecember 31.1990. or 6 months after theState determines that the ground watersource is under the direct influence ofsurface water, whichever is later, unlessthe Stale has determined that filtrationIs required in writing pursuant to114l2(b)(7)(C)(iii). in which case theState may specify alternative monitoringrequirements, as appropriate, untilfiltration is in place.

(1) Fecal coliform or total coliformdensity measurements as required byf 141.7l(a)(l) must be performed onrepresentative source water samplesimmediately prior to the first or onlypoint of disinfectant application. Thesystem must sample for fecal or totalcoliforms at the following minimumfrequency each week the system serveswater to the public

<VH>801 *> *,9»JJ01 to 1000Q-...10001 ton on> IS 000

Samptti/«*•*'

1234S

' Must b« Ukan on MfwraM day*.

Also, one fecal or total coliformdensity measurement must be madeevery day the system serves water tothe public and the turbidity of the sourcewater exceeds 1NTU (these samplescount towards the weekly coliformsampling requirement) unless the Statedetermines that the system, for logisticalreasons outside the system's control,cannot have the sample analyzed within30 hours of collection.

(2) Turbidity measurements asrequired by f 141 Jl(a)(2) must beperformed on representative grabsamples of source water immediatelyprior to the first or only point ofdisinfectant application every four hours(or more frequently) that the systemserves water to the public. A publicwater system may substitute continuousturbidity monitoring for grab samplemonitoring if it validates the continuousmeasurement for accuracy on a regularbasis using a protocol approved by theState.

(3) The total inaclivalion ratio foreach day that the system is in operation

27532 Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rule0 and Regulations

must be determined based on the CT»»jvalues in Tables 1.1-1.6. 2.1. and 3.1 ofthis section, as appropriate. Theparameters necessary to delenr.ine thetola] inactivation ratio must bemonitored as follows:

(i) The temperature of the disinfectedwater must be measured at least one*per day at each residual disinfectantconcentration sampling point

(ii) If the system uses chlorine, the pHof the disinfected water must bo

measured at least once per day at eachchlorine residual disinfectantconcentration sampling point

(iii) The disinfectant contact time(s)("T"] must be determined for each dayduring peak hourly flow.

(iy) The residual disinfectantconcentration(s) ("C") of the waterbefore or at the first customer must b«measured each day daring peak hourlyflow.

(v) If a system uses a disinfectantother than chlorine, the system maydemonstrate to the State, through theuse of a State-approved protocol for on-site disinfection challenge studies orother information satisfactory to theState, that CTWj values other than thosespecified In Tables 2.1 and 3.1 in thissection other operational parameters areadequate lo demonstrate that the system10 achieving the minimum inactivationrates required by 1141 -TZ(a)(l).

TABLE 1.1—CT VALUES (CTWJ) FOR 99.9 PERCENT INACTIVATION OP GMROIA LAMBLM CYSTS BY FREE CHLORINE AT 0.5 *C ORLOWER1

Reaidual (mo/I)

^B Ana

in

«4IB.i*

y J9 j

>•

^ Ban

. . PH<&0

137141.145140152199197162169160172179170101

64

163160172176100104100103107201209200213217

7.0

109200209210210221220231236242247252257261

74

237230240253250296273270200207200304310310

0.0

277260209304313321320330340353301360375362

04

320342354309376307307407417420439444452460

<«JJ

390407422437491464477400900911922933543992

1 TheM CT vakiM KfMve grMMr then • M.n percent Inactivation ot vtrueea. CT whjM between the ndc*«ed pH »mK*» miy be oelermned by IMeipolMon. CT vttu** between the indicated temperiurM of different tables may be determmed by linear interpoUDon. N no interpoiaton la uMd, UM the CT««value at the tower lemperaure and at the hgner pM.

•• *- • •

TABLE 1^— CT VALUES (CT *») for 99.9 PERCENT INACTIVATION OF GIAROIA UMBUA CYSTS BY FREE CHLORINE AT 5.0 *C'

FrMMwJucKmo/9

SOJOR

n«10\9ni«i»»B99»»

»•9m40

PH

a s.0

97100103109107100111114110110120122124126

6J

117120122129127130132135130140143

.146140

•101

7.0

139143146146152199199102109100172179170102

7.9

190171179170103107192100200204200213217221

04

106204210210221227232236243240293290263290

04

230244252260207274201207204300309312310324

ft JO

270201301312320320337349393301390379302300

1 Th«M CT vvhiM *cN*v« grMMr tMn a 90.90 ptrMrt ln«ct»»9fln of «*MM. CT vtfuM bttwMn VM Mcstod pH vtluM nwy b* 1*wmit*4 by SHMTWwpoUtoa CT vtfuM b»N»*<n »• indeatad tormvtbfM of SH**t WMM mty bt dtttrmrwd ty IAMT Inurpolttion. R no InurpoUwn to UMd. UM 0* CT»«Mkj* mt ma to»» Unv nkM uv< x> H» feofur nH . ••

TABLE 14— CT VALUES (CT «•.•) for 99.9 PERCENT INACTIVATION OF GIAROIA LAMBLM CYSTS BY FREE CHLORINE AT 10.0 *C»

FCM (MttMl <mo/0

»°4D*0*

t o . . . . . . . . . ^ .*i1.4 - ,

«*l«

OH • '

a 0.0

7370707000020300

19

. '06000204090000

' 101

IB

104107110112114110110122

74

129120131134137140144147

0.0

140193159162166170' 174' 170

04

177103100100200200211219

10.0

200210229234240247253250

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules nnd Regulations 27533

TABLE 1.3— CT VALUES (CT «,*) for 99.9 PERCENT INACTIVATION Of GIAROIA LAMBLIA CYSTS BY FREE CHLORINE AT 100 *C'—Continued

frtt rMtiual (mg/l)

?n1 19A .....

? • _ - . . , . . .., ... ..

?• - - ,? 0 . . . r _ . . . , . _ - - .

"A eo

870990929395

65

1C*10510?110111113

70

124127129131134137

PH

7.5

150153157160163166

80

16216619019*197201

85

2212252302342392*3

-90

26527)276281287292

CT value* act«ev« graater than • 99 93 pcroant inactwaxon ol wuiet CT valc«l b»tw*«n tn» «xfceat*d pH v*lu*s m,y tM a»««nio«a by lmc»i. CT value* between the nXMtrt Mmpe iiw** of OiUerent tables miy tM tfetemmeO by knear inUrpOUlon H no mcrpoUlon a used. tiM the CT..

value at m« lower «emper«iura. and at Ihe higher pH.

TABLE 1.4— CT VALUES (CT,,*) for 99.9 PERCENT INACTIVATION OF GIAROIA LAMBUA CYSTS BY FREE CHLORINE AT 15.0 'C1

*0.4

°*01

101J , . . ..14 , , j , r

«• .. .

1« . -

m. . ... ...»}94»a*aan

S6.0

495052S35455M57saM60616263

6.5

5960616364656666697072737476

7.0

707J737576767961636566666991

PH

7.5

6366669092949696100102104107109111

60

99102105106111114116119122124127129132134

65

118122126130134137141144147ISO153156159162

£30

;«o146151156160165169173177161164166191195

1 Theae CT vtfuea ach»»« great* fwi • 99.99 p*ro*m lnart*»«on of wut**. CT v»luM b«tw4wn Vw MtealM pH valutt m«y 6* 4et«nmtm+ton. CT valun b»t*mn m« imfeatad lt«np«r«WM of drflor*m MM** may b« &\*mrt*l by anaar ntaipoKMa H no ntaipolaMn • u»«dvalu* at ffi* lovar tamparaur*. and at Via tagnar pH.

o*clo*fflM^ad by fcneaf

TABLE 1.5—CT Values (CTNJ) FOR 99.9 PERCSNT INACTTVATTON Of GIAROW UMBUA CYSTS BY FREE CHLORINE AT 20 'C1

Raa nMiduai (mo/P

» ft 4

o«0«-1 0 . . . - - -1J .. -. . .... . . . . . . . . •1 . 4 , , . . . . . . . . . . .1 A

H . . . . . . . f _ ,

*o» J . . . _ — ,*4 . . .. .. . r

» • . _ ' . . . . . . .»•

?0--,. ..

1 Thma CT vahM* «cMm« •aXai twn a MM parcani inaeti«ation el vinjta*. CT valuat bat»«»afi IN

*aiua at v* lo««. lanvartkva. •««••« Not«a> pH

PH

<6.0

3636393940414249444445464747

6.5

444546474649SOSt52S354K

S*57

7.0

5254SS56575659616263656667M

7.5

62646667697072747577766061•3

6.0

74777961636567M91939597M

101

6.5

M9295M

100103105106110113its117119122

< 90

1051091131171201S3126129132135139141143146

Mieaiad pH vaK»i may b» dti*nnn*d bv **•>•rpoUkon H no wt»rpoUUon « mad. UM tft* CT- .

TABU 1.6—CT V«)UM (CTM«) FOR 99.9 PERCENT INACTIVATION OF GIAROIA LAMSUA CYSTS BY FREE CHLORINE AT 25 *C' ANDHIGHER

Free nwduM (mo/I)

.•04 j

fl* . ' ' . . .^ _ . . . ... • .. ..aa , .. ..1.0 . ,. ,^_j1.4 .. .. . __ .. • - Ml 1 .- _ - I I - , , . - . . .

— eo"

«s26MVV

6.5

ttM31313233

7.0

IS3637373639

74

424344454647

6.0

SOStS354SS57

^5

M6163656769

< 9 0

707375786062

27S34 Federal Register / Vol. 54. No. 124 / Thursday. June 29.19B9 / Rules and Regulations

TABLE 1.6—CT Values (CTW.,) FOB 99.9 PERCENT INACTIVATION OF GIAROIA LAMBLIA CYSTS BY FSEE CHLORINE AT 25 *C' ANDHIGHER—Continued

1 11 »70 , , , . . - . . _ .??7* ... , .... ... , ., , _. _?*.

.10

< 6.0

26a29303031It32

6.5

33343JJS343T3731

7.0

404141424344

44

PH

7.S

4049MSiS3S3

M

60

S660616263•6

•7

65

707274767776

•1

*9.0

6466•aw9294

97

1 These CT vetoes achieve greater tfian • 99.99 percent Inactivelion of vivnm. CT value* between Vie Mealed1 pH vetoes may tM delermned By Inear•ncrpouten CT value* between trie indicated temperature* o» diMerem UCM* may be deiemwied by linear interpolation. V no inurpoUbon it u*ed. UM Vie CT*»•«*»• at tfw tower temperature, end at (Me higher pH.

TABLE 2.1—CT VALUES (CTMJ) FOR 99.9 PERCENT INACTTVATION OF GIAROIA LAMBUA CYSTS BY CHLORINE DIOXIDE AND OZONE*

O4Qn«t *» tt

Qiorm i . - . . . . i j - . .. .«-

' Temperature

1X

632.9

s-c

M1J

10 V

a1.4

15X

190-95

20 X

tsa72

> ^J

11O4«

1 Tnue CT vatuet «cniev« 7*it*r tttan 99.99 percent inacttalnn e(rotation. M no mterpolaton « uMd. uae the CT., value at Vie

. CT vahiea between Vie Irnicaled lamperawea may be deieifliined by anearlamperatwe lor determining CU, vaJuea between ndcated Mmpeiawea.

TABLE 3.1—CT VALUES (CT „,) FOR 99.9PERCENT INACTTVATION OF GIAROIALAMBUA CYSTS BY CHLOAAMINES*

Temperaure

< 1•c

3.800

sx

tMO

10 X

1450

1SX

1.500

20X

1.100

25X

750

' Three vakiet are tot pH vakiet ol 6 to 9. TheeeCT vtbe« may be wtumed w ecrnove greater ttianW 99 percent mactvaiion ol viruM* only t enlomeu ttdod and mined in tne wafer prior to Vie tddiaonol ammoraa U One eondibon • no* met, the systemmuei demorxtraie. ba«44 on on-v'.e studies or otfiermlormebon. ss approved by the State, thai tnesyttem « acnjevmg ti least 99.99 percent inackva-

•on of viruee*. CT vaiuet between me indicatedwmpenitiret may be determined by linear mierpoia-tton. H no inte>poia<on ki ueed. use the CT« valueat Vw lower lempomture tor deiemwir CT,.,value* between Micaied tempi

(4) The total inactivatioa ratio muat becalculated aa follow*:

(i) If the tyitem use* only one point ofdisinfectant application, the *ystem maydetermine the total Inactivation ratiobaied on either of the following twomethods:

(A) One motivation ratio (CTcalc/CTt»j) ia determined before or at theTint customer during peak hourly flowand If the CTcalc/CT»* > 1.0. the 094

percent Giardia lamblia (Motivationrequirement has been achieved; or

(B) Succeuive CTcalc/CTVe* valuea,repreaenting aequenUal inactivatioaratio*, are determined between the pointof disinfectant application and a pointbefore or at the first customer duringpeak hourly flow. Under this alternative,the following method muit be used tocalculate the total inactivalion ratio:

(1J Determine1CTcalc

for each sequel)'

(25CTcalcAlcaic /

Add th» value* together ICTM« * CT

13) U/ CTcalc \

^ 07.7 /

the90JPer-centOaf-dia

motivation requirement hasbeen acliievcd.

(ii) If the system uses more than onepoint of disinfectant application beforeor at the first customer, the system mustdetermine the CT value of eachdisinfection sequence immediately priorto the next point of disinfectant

application during peak hourly flow. TheCTcalc/CTwj value of each sequenceand

CTcalc

must be calculated using the methodin paragraph (b)(4)(i](B) of this sectionto determine if the system is Incompliance with 1 142.72(a).

(iii) Although not required, the totalpercent inactivalion for a system withone or more points of residual

disinfectant concentration monitoringmay be calculated by solving thefollowing equation:

100Percent Inactivalion-100- —

! ' in-

wheres«3x

(9) The residual disinfectantconcentration of the water entering the

Federal Register / Vol. 54. No. 124 / Thursday, June 29.1989 / Rules and Regulations 27535

diitributlon system must be monitoredcontinuously, and the lowest value mustbe recorded each day. except that ifthere Is a failure In the continuousmonitoring equipment grab samplingevery 4 hours may be conducted in lieuof continuous monitoring, but for nomore than S working days following thefailure of the equipment, and systemsserving 3.300 or fewer persons may takegrab samples In lieu of providingcontlnous monitoring on an ongoingbasis at the frequencies prescribedbelow: . j

SOI to 1.000 —1.001 10 tSOO-

d*y».

1 Th» 6ff\ MmplMtm«. Th» '

w b* isk«n et 0* Mm*10 SUM

If at any time the residual disinfectantconcentration falls below 0.2 mg/1 in asystem using grab sampling in lieu ofcontinuous monitoring, the system musttake a grab sample every 4 hours untilthe residual concentration is equal to orgrea ter than 0-2 mg/1.

(6)(i) Th« residual disinfectantconcentration must be measured at leastat the same poir.ts in the distributionsystem and at the same time as totalcoliforms are sampled, as specified on1141.21. except that the State may allowa public water system which uses both asurface water source or a ground watersource under direct Influence of surfacewater, and a ground water source, tolake disinfectant residual samples atpoints other than the total cotifonnsampling points If the State determinesthat such points are more representativeof treated (disinfected) water qualitywithin the distribution system.Heterotrophic bacteria, measured ashe'terotraphlc plate count (HPC) asspecified In paragraph (a)(I) of tUasection, may be measured hi Vn etresidual disinfectant coactntration.' '

(II) If the State determines, based onalle-spedflc considerations, that tsystem has no means for having asample transported and analyzed forHPC by a certified laboratory under therequisite time and temperatureconditions specified by paragraph (a)(3)of this section and that the system Isproviding adequate disinfection in thedistribution system, the requirements ofparagraph (b)W(O of this section do notapply to that system.

(c) Monitoring nquirtmtnti fortyttemi uting filtration treatment. A

public water system that use* s surfacewater source or a ground water sourceunder the Influence of surface water andprovides filtration treatment mustmonitor in accordance with thisparagraph (c) beginning June 29.1993. orwhen filtration is installed whichever Islater.

(1) Turbidity measurements asrequired by 1141.73 must be performedon representative samples of thesystem's filtered water every four hours(or more frequently] that the systemserves water to the public. A publicwater system may substitute continuousturbidity monitoring for grab samplemonitoring if it validates the continuousmeasurement for accuracy on a regularbasis using a protocol approved by theState. For any systems using slow sandfiltration or filtration treatment otherthan conventional treatment directfiltration, or diatomaceous earthfiltration, the State may reduce thesampling frequency to once per day if itdetermines that less frequent monitoringis sufficient to indicate effectivefiltration performance. For systemsserving 500 or fewer persons, the Statemay reduce the turbidity samplingfrequency to. once per day. regardless ofthe type of filtration treatment used, ifthe State determines that less frequentmonitoring Is sufficient to'indicateeffective filtration performance.

(2) The residua] disinfectantconcentration of the water entering thedistribution system must be monitoredcontinuously, and the lowest value mustbe recorded each day. except that ifthere is a failure in the continuousmonitoring equipment, grab samplingevery 4 hours may be conducted in lieuof continuous monitoring, but for nomore than S working days following thefailure of the equipment and systemsserving 3.300 or fewer persons may taktgrab samples in lieu of providingcontinuous monitoring on an ongoingbasis at the frequencies each dayprescribed beta*:

Sydwn tfe* by popUMofl

U01103400-

1_ 2

34

1 Th* M/S MmplM etnnM M Uk«n «t tw Mm*Smt. Tn* Mrnpjjna kiMrvU) «r» *uti*ei to Sl«Mw*** and cppfovw.

If at any time the residual disinfectantconcentration falls below 0.2 mg/1 In asystem using grab sampling in lieu ofcontinuous monitoring, the system musttake a grab sample every 4 hours until

the residual disinfectant concentrationis equal to or greater than 0.2 mg/1.

(3)(i) The residual disinfectantconcentration must be measured al leastat the same points in the distributionsystem and at the same time as totalcoliforms are sampled, as specified ini 141.21. except that the State may allowa public water system which uses both asurface water source or a ground watersource under direct influence of surfacewater, and a ground water source totake disinfectant residual sampled atpoints other than the total coliformsampling points if the State determinesthat such points are more representativeof treated (disinfected) water qualitywithin the distribution system.Heterotrophic bacteria, measured asheterotrophic plate count (HPC) asspecified in paragraph (a)(3) of thissection, may be measured in lieu ofresidual disinfectant concentration.

(ii) If the State determines, based onsite-specific considerations, that asystem has no means for having asample transported and analyzed forHPC by a certified laboratory under therequisite time and temperatureconditions specified by paragraph (a)(3)of this section and that the system isproviding adequate disinfection in thedistribution system, the requirements ofparagraph (c)(3)(l) of this section do notapply to that system.

f 141.7S Reporting and recorakeepfciQrequirements*

(a] A public water system that uses asurface water source and does notprovide filtration treatment must reportmonthly to the State the informationspecified in this paragraph (a) beginningDecember 31.1990. unless the State hasdetermined that filtration is required inwriting pursuant to section1412(b)(7)(C)(iii). in which case the Statemay specify alternative reportingrequirements, as appropriate, untilfiltration Is in place. A public watersystem that uses a ground water sourceunder the direct influence of surfacewater and dots not provide filtrationtreatment must report monthly to the

• State the information specified in thisparagraph (a] beginning December 31.1990. or 6 months after the Statedetermines that the ground water sourceis under the direct influence of surfacewater, whichever Is later, unless theState has determined that filtration isrequired in writing pursuant to11412(b)(7: C)(ili). in which case theSlate may »pecify alternative reportingrequirements, as appropriate, untilfiltration Is in place.

(1) Source water quality informationmust be reported to the State within 10

27536 Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations

d.iys after the end of each month thesysica> serves water to the public.Information that must be reportedincludes:

(1) The cumulative number of monthsfur which results are reported.

(it) The number of fecal and/or totalcolifonn samples, whichever areanalyzed during the month (if a systemmonitors for both, only fecal coliformsmust be reported), the dates of samplecollection, and (he dates when theturbidity level exceeded \ NTU.

(iii) The number of samples during themonth that had equal to or less than 20/100 ml fecal coliforms and/or equal to orloss than 100/100 ml total coliforms,whichever are analyzed.

(iv) The cumulative number of fecal ortotal colifonn samples, whichever areanalyzed during the previous sixmonths the system served water to thepublic.

(v) The cumulative number of samplesthat had equal to or less than 20/100 mlfecal colifurms or equal to or less than100/100 ml total coliforms, whichever 'are analyzed during the previous sixmonths the system served water to thepublic.

(vi) The percentage of samples thathad equal to or less than 20/100 ml fecalculiforms or equal to or l«ss than 100/100 ml total coliforms, whichever areanalyzed during the previous sixmonths the system served water to thepublic

(vii) The maximum turbidity levelmeasured during the month, the date(s)of occurrence foe any measurements)which exceeded S NTU, and the date(s)the occurrence(s) was reported to theState.

(viii) For the first 12 months ofrecordkeeping. the dates and cumulativenumber of events during which theturbidity exceeded 5 NTU, and after oneyear of recordkeeping for turbiditymeasurements, the dales and cumulativenumber of events during which theturbidity exceeded 3 NTU in theprevious 12 months the system servedwater to the public

(ix) For the first 120 months ofrecordkeeping, the dates and cumulativenumber of events during which'theturbidity exceeded S NTU. and after 10years of recordkeeping fur turbiditymeasurements, the dates and cumulativenumber of events during which theturbidity exceeded S NTU in theprevious 120 months the system servedwater to the public

(2) Disinfection information specifiedin { 141.74(b) must be reported to theState within 10 days after the end ofisaeh month the system serves water tothe public. Information that must bereported includes:

(i) For each day. the lowestmeasurement of residual disinfectantconcentration in mg/1 in water enteringthe distribution system.

(ii) The dale snd duration of eachperiod when the residual disinfectantconcentration in water entering thedistribution system fell below 0.2 mg/1and-when the Stale was notified of theoccurrence.

(iii) The daily residual disinfectantconcentration(s) (in mg/1) anddisinfectant contact lime(s) (in minutes)used for calculating the CT vaiue(s).

(iv) If chlorine is used, the dailymeasurement(s) of pH of disinfectedwater following each point of chlorinedisinfection.

(v) The daily measurcment(s) of watertemperature in *C following each pointof disinfection.

(vi) The daily CTcalc and CTcalc/CT*.t values for each disinfectantmeasurement or sequence and the sumof all CTcalc/CT»« values ( (CTcalc/CTft j)) before or at the Tint customer.

(vii) The daily determination ofwhether disinfection achieves adequateCiardia cyst and virus inactivation, i.e,whether (CTcalc/CTw*) is at least 1.0or, where disinfectants other thanchlorine are used, other indicatorconditions that the State determines areappropriat*. are met

(viii) The following information on thesamples taken in the distribution systemin conjunction with total colifonnmonitoring pursuant to 1141.72:

(A) Number of instances where theresidual disinfectant concentration ismeasured:

(Bl Number of instances where theresidua] disinfectant concentration isnot measured but heterotrophic bacteriaplate count (HPC) Is measured;

(C) Number of instances where theresidual disinfectant concentration ismeasured but not detected and no HPCis measured:

(0) Number of instances where theresidual disinfectant concentration isdetected and where HPC is >500/ml:

(£) Number of instances where theresidual disinfectant concentration isnet measured and HPC is >500/ml;;

(F) For the current and previousmonth the system served water to thepublic, the value of "V" in th« followingformula:

xlOOa+b

where«-th« value In paragraph («X2)(viii)(A) of

Otit Motion.b-th» vttlua in p*rugr»ph (a)(2HviiiKD) of

ibis faction.

c«th« value In paragraph (a)(2)(viii)(C) ofthis section.

J»lhe value In paragraph (*)(2)(viii](D) ofthis section. «nd

e«the valut in paragraph (a)(2)(vlii)(E) ofthis section.

(G) If the State determines, based onsite-specific considerations, that asystem has no means for having asample transported and analyzed forHPC by a certified laboratory under therequisite time and temperatureconditions specified by {141.74(a)(3)and that the system is providingadequate disinfection in the distributionsystem, the requirements of paragraph(tJ(2)(viu)(AHF) of this section do notapply to that system.

(ix) A system need not report the datalisted in paragraphs (a](2)(i), and (iii)-(vi) of this section if all data listed inparagraphs (a)(2) fiHv"1) of Ihui sectionremain on file at the system, and theState determines that

'(A) The system has submitted to theState all the information required byparagraphs (a)(2) (IHviii) of this sectionfor at least 12 months: and

(B) The State has determined that thesystem is not required to providefiltration treatment

(3) No later than ten days after theend of each Federal fiscal year(September 30). each system mustprovide to the State a report whichsummarizes its compliance with allwatershed control program requirementsspecified m| 141.71 (b)(2).

(4) No later than ten days after theend of each Federal fiscal year(September 30). each system mustprovide ta the State a report on the on-site inspection conducted during thaiyear pursuant to i 141.71(b)(3). unlessthe on-site inspection was conducted bythe State. If the Inspection wasconducted by the State, the Slate must'provide a copy of its report to the publicwater system.

(5}(i) Each system, upon discoveringthat a waterbome disease outbreakpotentially attributable to that watersystem has occurred, must repot«that 'occurrence to the State as soon aspossible, but no later than by the end ofthe next business day.

(Ii) If at any time the turbidity exceedsS NTU. the system must inform the Staleas soon as possible, but no later than theend of the next business day.

(ill) If at any lime the residual fallsbelow 0X2 mg/1 in the water entering thedistribution system, the system mustnotify the Slate as soon as possible, butno later than by the end of the nextbusiness day. The system also mustnotify the Slate by the end of thu nuMbusiness day whelhar or not th« reaiJuul

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and Regulations 27337

was restored lo at least 0-2 mg/1 within 4hours.

(h] A public water system that uses asurface water source or a ground watersource under the direct mfluence ofsurface water and provides filtrationtreatment most report monthly to IheState the information specified in thisparagraph (b) beginning June 29.1993. orwhen nitration is installed, whichever is •later.

(1) Turbidity measurements asrequired by 114l.74(c)(1) mast bereported within 10" days after the end ofeach month the system serves water toIhe public. Information that must bereported includes:

(1) The total number of filtered waterturbidity measurem-r.is taken during themonth.

(ii) The number anr. percentage offiltered water turbidity measurementstaken during the month which ere lessthan or equal to the turbidity limitsspecified hi i 141.73 for the filtrationtechnology being used.

(iii) The date and value of anyturbidity measurements taken during themonth which exceed 5 NTU.

(2) Disinfection information specifiedin i I4!.74(c) must be reported to theState within 10 days after the end ofeach month the system serves wafer lothe public Information that must bereported includes:

(i) For each day. the lowestmeasurement of residual disinfectantconcentration in mgA in water enteringthe distribution system.

(ii) The date and duration of eachperiod when the residual disinfectantconcentration m water entering thedistribution system fell below 0-2 mg/land when the State was notified of theoccurrence.

(iii) The following information on thesamples taken in the distribution systemin conjunction with total coliformmonitoring pursuant lo 1141.72:

(A) Number of instance* where theresidual disinfectant concentration Itmeasured;

(B) Number of instance*-where theresidual disinfectant concentration Icnot measured but h*ter*4ropn4c bacteriaplate coont (HPQ (• meMfjrtd:

(C) Number of instance* where theresidual disinfectant concentration i*messured but no! detected1 and no HPCis measured;

(D) Number of instance* where noresidual disinfectant concentration 1*delected and where HPC la >SOO/m):

(E) Number of instances where theresidual disinfectant concentration isnot measured and HPC i* >500/mh

(F) For the current and previousmonth Ihe system serves water to Ihe

XNW

public, the value of "V" in the followingformula:

V»

wherea-the value In paragraph (b)(2)(iii)(A) of this

Motion,b-lhe value in paragraph (b)(2)(iii)(B) of this

section,c-lhe value in paragraph (b)(2)(iii)(C) of this

section,d-lhe value in paragraph (b)(2)(iii)(D) of this

section, ande-lhe value In paragraph (b)fZ)0n)fE] of this

section.(C) If the State determines, based on

site-specific considerations, that asystem has no means for having asample transported and analyzed forHPC by a certified laboratory within therequisite time and temperatureconditions specified by i 14174(a}(3)and that the system is providingadequate disinfection in the distributionsystem, the requirements of paragraph(b)(2)(iii)(AHF) of this section do notapply.

(iv) A, system need not report the datalisted in paragraph (b)(2)(i) of thiasect) an if all data listed in paragraphs(b)(2)(i)-(iii) of this section remain onfile at the system and the Statedetermines that the system hassubmitted all the information requiredby paragraphs fb)(2)(i)-(ii>) of thiasection for at least 12 months.

(3)(i) Each system, upon discoveringthat a waterborne disease outbreakpotentially attributable to that watersystem-has occurred, must report thaioccurrence to the State as soon as-possible, but no later than by the end ofthe next business day.

(Ii) If at any time the turbidity exceedsS NTU. the system must inform the Stateas soon as possible, but no later than theend of the next business day.

(iii) If at any time the residual fallsbeluw 0.2 mg/1 in the water entering thedistribution system, the system mostnotify the State as soon as possible, butno later than by the end of the nextbusiness day. The system also muttnotify the Stale by the end of the nextbusiness day whether or not the residualwas restored lo al least O2 mg/1 within 4hours.

PART 142—NATIONAL PRIMARYDRINKING WATER REGULATIONSIMPLEMENTATION

1. The authority citation for Purl 142 isrevised lo read as follows:

Authority: 42 U.S.C 300f. WOg-t. 300K-Z.JOOa-1. 300R-4. XK>t-S.300J-*

2. Section 142.14 i3 amended byrevising paragraph (a) introductory trxl.(a)fl)(iii). U)(3) introdudory text. (a)(4)anil rcdesignating it as paragraph (;i)[f>).and by adding new paragraphs (a)(4)and by ridding and reserving paragraph(a)(S) to rearl as follows:

{ 142.14 Records kept by States.

(a) Each State which has primaryenforcement responsibility shallmaintain records of tests,measurements, analyses, decisions, anddeterminations performed on eachpublrc water system to determinecompliance with applicable provisionsof Slate primary drinkfhg waterregulations.

(1J ' * *(iii) The analytical results, set forth in

a form which nukes possiblecomparison with the limits specified inil 141.63.141.71. and 141.72 of thinchapter.

(S\ Records of turbidity measurementsshall be kept for not less than one year.The information retained must be setforth in a form which makes possiblecomparison with the limits specified in|{ 141.71 and T41.73 of this chapter.Until June 29.1993. for any public tvatrrsystem which is providing filtrationtreatment and until December 30. iflffl.for any public water system notprovfding filtration treatment and notrequired by (he State to providefiltration treatment, records kept nmslbe set forth m a form which makespossible comparison with Ihe limitscontained in 1141.13.

(4)(i) Records of disinfectant residualmeasurements and other parametersnecessary lo document disinfectioneffectiveness in accordance with|| 141.72 nnd 141.74 of this chapter nn<lthe reporting requirements of i UI.7S ofthis chiipler shitll be kept for mil If**than one year.

(ii) Record* of decisions made on asysletn-by-sy«t«m and case-by-cus*basis under provisions of Part 141.Subpart H. ahull be made in writing amikept al the Star*.

(Al Record* of decisions matte umfcrthe following provision* shall be k*plfor 40 years (or until one year after thedecision is reversed or revised) and acopy of the decision must be provided lothe system:

(/) Section 141.73(aJ(lr—Any oVcininnto n'.low a public water system usingconventional fillirtlon rr Ml men ordirect filtration to siilwli' ite a tiTlitiliiylimit greater thnn 0.5 NTU:

(2\ Section T41.73(b)(D—Any dwninnlo Hllnw H public water xystem ti*ini>

27538 Federal Register / Vol. 54. No. 124 / Thursday. June ,.9.1989 / Rules and Regulations

slow sand filtration to substitute alurb id i ty limit greater than 1 NTU;

(J) Section 141.74(b)(Z)—Any decisionto allow an unfillered public watersystem to use continuous turbiditymonitoring:

(•!) Section 141.74(b)(6)(iJ—Anydecision to allow an unfiltered publicwater system to sample residualdisinfectant concentration at alternatelocations if it also has ground watersource(s):

(3) Section 141.74(c)(1)—Any decisionto :illuw a public water system usingfiltration treatment to use continuouslurbidity monitoring; or a public watersystem using slow sand filtration orfiltration treatment other thenconventional treatment, direct filtrationor dialomaceous earth filtration toreduce turbidity sampling to once perday, or for systems serving 500 people orfewer to reduce turbidity sampling toonce per day:

(61 Section 141.74(c)(3)(i)—Anydecision to allow a filtered public watersystem to sample disinfectant residualconcentration at alternate locations if italso has ground water source(*h

(/-) Section 141.75(a)(2)(ixJ—Anydecision to allow reduced reporting byan unfiltered public water system: and

(tf) Section 141.75(b)(2)(!v}—Anydecision to allow reduced reporting by afiltered public water system.

(D) Records of decisions made underthe following provisions shall be keptfor one year after the decision is made:

(/) Section 141.7l(b)(lJ(i>-Anydecision that a violation of monthly CTcompliance requirements was caused bycircumstances that were unusual and .unpredictable.

(*) Section 141.71(b)(lJ(iv}—Anydecision that a violation of thedisinfection effectiveness criteria wasnot caused by a deficiency in treatmentof the source water

(J) Section 141.n(b)(S}—Any decisionthai a violation of the total colifonnMCL was not caused by • deficiency intreatment of the source water:

U] Section I41.74(b)(l)—Any decisionthat total coliform monitoring otherwiserequired because the turbidity of thesource water exceeds 1 NTU is notfeasible, except that if such decision{•Hows a system to avoid monitoringwithout receiving Slate approval in eachinstance, records of the decision shall bekept until one year after the decision isrescinded or revised.

(C) Records of decisions made underthe following provisions shall be keptfur the specified period or 40 years,whichever is less.

(71 Section 141.71(a)(2)(i>—Anydecision that sn event in which thesource water turbidity which exceeded 9

NTU for an unfiltered public watersystem was unusual and unpredictableshall be kept for 10 years.

(2} Section 141.71(b)(l)(iii)—Anydecision by the Slate that failure to meetthe disinfectant residual concentrationrequirements of 1141.72(a)(3J(i) wascaused by circumstances that wereunusual and unpredictable, shall be keptunless filtration is installed. A copy ofthe decision must be provided to thesystem.

(J) Section 141.71(b)(2r—Any decisionthat a public water system's watershedcontrol program meets the requirementsof this section shall be kept until thenext decision is available and filed.

(4) Section I4l.70(c}—Any decisionthai an individual is a qualified operatorfor a public water system using asurface water source or a ground watersource under the direct influence ofsurface water shall be maintained untilthe qualification ls withdrawn. TheState may keep this information in theform of a list which is updatedperiodically. If such qualified operatorsare classified by category, the decisionshall Include that classification.

(5) Section 141.71(bJ(3>—Any decisionthat a party other than the State isapproved by the State to conduct on-siteinspections shall be maintained untilwithdrawn. The Slate may keep thisinformation in the form of a list which isupdated periodically.

(0) Section 141.71(b){4}—Any decisionthat an unfiltered public water systemhas been identified as the source of awaterbome disease outbreak, and. Ifapplicable, that it hit been modifiedsufficiently to prevent another suchoccurrence shall be kept until filtrationtreatment is installed. A copy of thedecision must be provided to the system.

(7) Section 141.72—Any decision thatcertain interim disinfection requirementsare necessary for an unfiltered publicwater system for which the State hasdetermined thai filtration is necessary,and a list of those requirements, shall bekept until filtration treatment isinstalled. A copy of the requirementsmust be provided to the system.

(8} Section 141.72(a)(21(ii}—Anydecision that automatic shut-off ofdelivery of water to the distributionsystem of an unfillered public watersystem would cause an unreasonablerisk to health or interfere with fireprotection shall be kept until rescinded.

(9} Section I41.72(t)(4)(ii)—Anydecision by (he State, based on site-specific considerations, that anunfillered system has no means forhaving a sample transported andanalyzed for UPC by a certifiedlaboratory under the requisite lime andtemperature conditions specified by

5 14V74(aj(3) and that the system isproviding adequate disinfection in thedistribution system, so that thedisinfection requirements contained in§ 141.72(a)(4)(i) do not apply, and thebasis for the decision, shall be kept untilthe decision Is reversed or revised. Acopy of the decision must be provided tothe system.

(10) Section 141.72(b)(3)(ii)—Anydecision by the State, based on site-specific conditions, that a filteredsystem has no means for having asample transported and analyzed for11PC by a certified laboratory under therequisite time and temperatureconditions specified by f 14l.74(a)(3)and that the system U providingadequate disinfection in the distributionsystem, so that the disinfectionrequirements contained ini I41.72(b)(3)(i) do not apply, and thebasis for the decision,'shall be kept untilthe decision Is reversed or revised Acopy of the decision must be provided tothe system. .

(11) Section 141.73(d)—Any decisionthat a public water system, havingdemonstrated to the Slate that analternative filtration technology, incombination with disinfection treatmentconsistently achieves 99.9 percentremoval and/or inactivation of Ciardiaiomblia cysts and 99.99 percent removaland/or inactivation of viruses, may usesuch alternative filtration technology,shall be kept until the decision isreversed or revised. A copy of thedecision must be provided to the system.

(12] Section 141.74(b), Table 3.1—Anydecision that a system using either .preformed chloramines or chloramines •formed by the addition of ammonia priorto the addition of chlorine hasdemonstrated that 99.99 percent removaland/or Inactivation of viruses has beenachieved at particular CT values, and alist of (hose values, shall be kept untilthe decision Is reversed or revised. Acopy of the list of required values mustbe provided to the system.

(13] Section 141.74(b)(3){v}—Anydecision that a system using •disinfectant other than chlorine may useCTwj values other than those in Tables2.1 or 3.1 fend/or other operationalparameters to determine if the minimumtotal inactivation rates required by1141.72(aHD ere being met. and what 'those values or parameters are. shall bekept until the decision is reversed orrevised. A copy of the list of requiredvalues or parameters must be providedto (he system.

(MJ Section 142.l6(b)(2)(t)(B|—Anydecision that a system using a groundwater source is under the directinfluence of surface water.

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rutes and Regulations 27539

(in] Record* of any determination that• public water system supplied by •surface water source or • ground watersource under the direct influence ofsurface water is not required to-providefiltration treatment shall be kept for 40yc.irs or until withdrawn, whichever isearlier. A copy of the determination •must be provided to (he system.

(5) (Reserved)(6) Records of analyses for

contaminants other than microbiologicalcontaminants (including total coliform.fecal coliform. and heierctrophac platecount), residua) disinfectantconcentration, other parametersnecessary to determine disinfectioneffectiveness (inchiding temperature andpH measurements), and turbidity, mustbe retained for not less than 40 yeanand shall include at least the followinginformation:

(i) Date and place of sampling,(if) Date and results of analyses.

• » • • «3. Section 142.15 Is amended by

adding paragraphs (b)(3) and (4) andparagraph («} to read M follows:

1142.15 Report* by Staff*.« * • « •

ft)***(3) A fist identifying the name. PWS

identification number and date of the 'determination for each public watersystem supplied by a surface watersource or a ground water source underthe direct influence of surface water.which the Slate has determined fa notrequired to provide filtration treatment.

(4) A list identifying the name andPWS identification number of eachpublic water system supplied by asurface water source or ground watersource under the direct influence ofsurface water, which the Suta hasdetermined, based on an evaluation ofsite-specific considerations, hat nomear.s of having a sample transportedand analyzed for HPC by a certifiedlaboratory under Che requisite time andtemperature conditions specified in1141.74(a)(3) and Is providing adequatedisinfection in the disl/ibultoc ayslam.regardless of whether the tyatem la incomplinncc with the criteria of1141.?2(a)(4](i) or (b)(3)(i) of thischapter, as allowed by 1141.72(a)(4)(ii)and (b)(3)(ii). The list must include theeffective date of each determination.• • • • •

(») Notification wilhin 60 days of theend of the calendar quarter of anydetermination that a public watersystem using a surface water source or aground water source under the directinfluence of surface water la aolrequired to provide nitration treatment

The notification must include astatement describing the system'scompliance with each requirement of theStale's regulations that implementi 141.71 and a summary of comments, ifany, received from the public on thedetermination. A single notification maybe used to report two or more suchdeterminations.

4. Section 142.18 is amended byadding paragrnph (b) to read as follows:

J 142.16 SpecUl primacy requirements.• • » • •

(b) Requirements for Stolen lo adopt40 CFR Port 141. Subpart H Filtrationand Disinfr ::icn. In addition to thegeneral primacy requirementsenumerated elsewhere in this part,including the requirement that Stateprovisions are no less stringent than thefederal req jiremerts. an application forapproval of a State program revisionHut adopts 40 CFR Part 141. Subpart HFiltration and Disinfection, must containthe information specified in Jhisparagraph (b). except (hat States whichrequire without exception all publicwater systems using a surface watersource or a ground water source underthe direct influence of surface water foprovide nitration need not demonstratethat the State program has provisions .that apply to systems which do notprovide filtration treatment However,such Statea must provide the text of theState statutes or regulations whichspecifies that all public water systemsusing a surface water source or a groundwater source under the direct Influenceof surface water must provide filtration.

(1) Enforceable requirements. Inaddition to adopting criteria no lessstringent than those specified in Part '141. Subpart H of this chapter, theState's application must Includeenforceable design and operatingcriteria for each nitration treatmenttechnology allowed or a procedure forestablishing design and operatingconditions on a system-by-systcm basis(e.g., a permit system).

(2) State prod ices or procedures, (i) AStale application for program revisionapproval must include a description ofhow the State wifl accomplish thefollowing:

(A) Section 141.70(c) (qualification ofoperators}—Qualify operators ofsystems using a surface water source ora ground water source under the directinfluence of surface water.

(D) Determine which systems using aground water source are under the directinfluence of surface water by June 29.1994 for community weter systems andby |ane 2% 1009 for non-communitywater system*.

(C| Section 141.72(b)(l) (achinvmj?required Ciardia lamblia and vimsremoval in filtered systems)—Det<*rmirvthat the combined treatment processincorporating disinfection treatment nn<!f i l t rat ion treatment will achieve therequired removal and/or in.icrivatfon ofCiordia lomblia anrl vinises.

(D) Section 14l.74fa) (Slate flpprov.ilof parties to conduct analyses)—approve parties to conduct pH.temperature, turbidity, and residualdisinfectant concentrationmejsuremcrij.

(F) Dcterrvnc approprimo filtnitiontreatment technology for source wnt«rsof various qunlilies.

(! For a Slate which docs not requireall public water systems using a surfacewater source or ground water sourceunder the direct influence of surfacewater to provide filtration treatment, aSlate application for program revisionapproval must include a description ofhow the StHte will accomplish thefollowing:

(A) Section 141.71 (bjf2) (watershedcontrol program}—Judge the adequacyof watershed control programs.

(B) Section 141.71(b)(3) (approval ofon-site inspectors]—Approve on-siteinspectors other than Stale personnelH-.d evaluate the results of on-site•; ipeclions,

Uii) For a Slate which adopts any off-u following discretionary element* ofFnrt 141 of this chapter, the applicationmust describe how the State will:

(A) Section 141.72 (interimdisinfection requirements)—Dcinrminointerim disinfection requirements forunfiltcred systems which the Sute hasdetermined must filter which will be ineffect until filtration is installed.

(D) Section 141.72(a)(4)(ii) and(b)(3)(ii) (determination of adequM**disinfection in system withoutdisinfectant residual}—Determine thai asystem is unable to measure HPC but iaslill providing adequate disinfection inthe distribution system, as allowed by| 141J2(«)(4)(ii) for systems which donot provide filtration treatment and1141.72(D)(3P) for system* which doprovide filtration treatment.

(C) Section 141.73|aKD and (b)|i)(alternative turbidity limit)—Determinewhether an alternative turbidity limit Inappropriate and whitt the lex-el nhouMbe as allowed by I I41.73(a)(l) for axyslom using conventional filtrationtreatment or direct filtration and byi 14l.73(b)(l] for a system using slowsand filtration,

(D) Section 141.73(d) (alternativefiltration technologies}—Determfne thata public water system has demonstrated(hat nn alternate filtration technology, in

27540 Federal Register / Vol. 54. No. 124 / Thursday, {une 29.19fc9 / Rules and Regulations

cumbinution wi th disinfection treatment,achieves adequate removal and/ordisinfection of Giardin hmblio andviruses.

(F) Section M1.74(a)(5) (alternatea.'icjlytical me'.hud for chlorine]—Approve DPD colorimetric test kits forfree and combined chlorinemeasurement or approve calibration ofautomated methods by the IndigoMethod for ozone determination.

(F) Section 141.74 (bj(2) and (c](l)(iipproval of continuous turbiditymonitoring)—Approve continuousturbidity monitoring, us allowed byi I41.74(bj(2) for a public water systemwhich does not provide nitrationtreatment and i 141.74(c)(l) for a systemwhich does provide nitration treatment

(C) Section 141.74 (b)(fl)(i) and (c)(3)(i)(approval of alternate disinfectantresidual concentration samplingplans)—Approve alternate disinfectantresidual concentration sampling plansfor system* which have a combinedground water and surface water orground water and ground water underthe direct influence of a surface waterdistribution system, as allowed by$ I41.74(b)(8)(i) for a public watersystem which does not provide filtrationtreatment and § 141.74(c)(3)(i) for apublic water system which docs providefiltration treatment.

(H) Section 141.74(c)(l) (reduction ofturbidity monitoring)—^Decide whetherto allow reduction of turbiditymonitoring for systems using slow sandfiltration, en approved alternatenitration technology or serving 500people or fewer.

(I) Section 141.75 (a)(2)(ix) and(bJ(Z)(iv) {reduced reporting)—Determine whether reduced reporting Unppropriate. as allowed byJ 14l.75(a)|2)(ix) for a public wittersystem which does not provide nitrationirciilment and 1141.73(b)(2)(tv) for •public water system which does providefiltration treatment

(iv) For a. Slate which doe* not requireall public water systems using a surfacewater source or ground water sourceunder the direct influence of surfacewuter to provide filtration treatment andwhich uses any of the followingdiscretionary provisions, the applicationmust describe how the State will:

(A) Section 141.71(a)(2)(i) (sourcewater turbidity requirements)— .Determine that an exceedance ofturbidity limits in source water wascaused by circumstances that wereunusual and unpredictable.

(B) Section 141.71(b)(l)(i) (monthly CTcompliance requirements}—-Determinewhether failure to meet the requirementsfor monthly CT compliance Inf 141.72(a)(l) was caused by

circumstances that were unusual andunpredictable.

(C) Section 141.7l(b)(l)(iii) (residualdisinfectant concentrationrequirements)—Determine whetherfailure to meet the requirements forresidual disinfectant concentrationenuring the distribution system in{ 14i.72(a)(3)(i) was caused bycircumstances that were unusual andunpredictable.

(DJ Section 141.71(b)(l)(iv)(distribution system disinfectantresidual concentration requirements)—Determine whether failure to meet therequirements for distribution systemresidual disinfectant concentration inJ I4l.72(a)(4) was related to a deficiencyin treatment

(E) Section. 141.71(b)(4) (systemmodification to prevent waterbomedisease outbreak)—Determine that •system, after having been identified asthe source of a waterbome diseaseoutbreak, has been modified sufficientlyto prevent another such occurrence.

(F) Section 141.7l(b)(5) (total coliformMCL)—Determine whether a totalcoliform MCL violation was caused by adeficiency in treatment.

(G) Section 141.72(a)(l) (disinfectionrequirements)—Determine that differentozone, chloramine. or chlorine dioxideCTt»» values or conditions are adequateto achieve required disinfection.

(H) Section 141.72(a;(2](ii) (shut-off ofwater to distribution system)-—Determine whether a shut-off of water tothe distribution system when thedisinfectant residual concentrationentering the distribution system is lessthan 0~2 ma/1 will cause anunreasonable risk to health or interferewith Tire protection.

(I) Section 141.74(b)(l) (coliformmonitoring)—Determine that coliforrnmonitoring which otherwise might berequired is not feasible for a system.

(J) Section 141.74(b). Table 3.1(disinfection with chloramines)—Determine the conditions to be met toinsure 90.09 percent removal and/orinactivation of viruses in systems whichuse either preformed chloramines orchloramiaes for which ammonia isadded to the water before chlorine, asallowed by Table 3.1.

S. New i 142.64 is added to read asfollows:

1142.S4 Variances and exemptions fromtne requirements of Part 141, Subpart H—nitration and Disinfection.

(a) No variances from therequirements in Part 141. Subpart H arepermitted.

(b) No exemptions from therequirements in 1141.72(a)(3) and (b)(2)to provide disinfection are permitted

6. Subpart I is added to read asfollows:

Subpart I—Administrator's Review of St»uDecisions that Implement Criteria UnderWhich Filtration Is Required

'See.142JO Review procedures.142.81 Notice lo th« Stile.

Subpart t—Administrator's Review ofSlate Decisions that ImplementCriteria Under Which Filtration IsRequired

I142.M Review procedures.(a) The Administrator may initiate a

comprehensive review of the decisionsmade by States .with primaryenforcement responsibility to determine,in accordance with 1141.71 of thischapter. If public water systems usingsurface water sources must providefiltration treatment. The Administratorshall complete this review within oneyear of its initiation and shall schedulesubsequent reviews as (s]he deemsnecessary.

(b) EPA shall publish notice of aproposed review in the Federal Register.Such notice must:

(1) Provide information regarding thelocation of data and other informationpertaining to the review to be conductedand other Information including newscientific matter bearing on theapplication of the criteria for avoidingfiltration: and .

(2) Advise the public of theopportunity to submit comments.

(c) Upon completion of any suchreview, the Administrator shall notifyeach Stale affected by the results of thereview and shall make the resultsavailable to the public.

I142J1 Notice to the State.(a) If the Administrator finds through

periodic review or other availableinformation that a State (1) has abusedits discretion In applying the criteria foravoiding filtration under 1141.71 of thischapter In determining that a systemdots not have to provide filtrationtreatment, or (2) has failed to prescribecompliance schedules for those systemswhich must provide filtration inaccordance with section 1412(b)(7)(C)(il)of the Act (s)he shall notify the State ofthese findings. Such notice shall:

(1) Identify each public water systemfor which the Administrator finds theState has abused Its discretion:

(2) Specify the reasons for the finding:(3) As appropriate, propose that the

criteria off 141.71 of this chapter beapplied property to determine the needfor a public water system to providefiltration treatment or propose a revised

Federal Register / Vol. 54. No. 124 / Thursday. June 29.1989 / Rules and R e g u l a t i o n s 275-11

tchcdulc ."or compliance by the publictvttlcr lyslcm with the filtrationfcaiment requirements:

(bl The Adminis t ra tor shall also notifythe State (hat a public hearing is to beheld on (he provisions of (he noticerequired by paragraph (a) of (his section.Scch notice shall specify the time andlocation of the hearing. If. uponnotification of a finding by theAdministrator that the State has abusedits discretion under f 141.71 of thischaplnr. the State lakes correctiveaction satisfactory to the Administrator,the Administrator may rescind thenotice to the State of a public hearing.

(c) The Administrator shall publishnotice of the public hearing in theFederal Register and in a newspaper ofgeneral circulation in the involved State,including a summary of the findingsmade pursuant to paragraph (a) of thissection, a statement of the time andlocation for the hearing, and the addressend telephone number of an office »twhich Interested pcrnont may obtain

further informntion concerning thehearing.

(d) Hearings convened pursuant toparagraphs (b) and (c) of this sectionthai! be conducted before a hearingofficer to be designated by theAdministrator. The hearing shall beconducted by the hearing officer in aninformal, orderly, and expeditiousmanner. The hearing officer shall havethe authority to call witnesses, receiveoral and written testimony, and takesuch other action as may be necessaryto ensure the fair and efficient conductof the hearing. Following the conclusionof the hearing, the hearing officer maymake a recommendation to theAdministrator based on the testimonypresented at the hearing and shallforward any such recommendation andthe record of the hearing to theAdministrator.

(e) Within 160 days after the datenotice is given pursuant to paragraph (b)of this section, the Administrator (hall:

(1) Rescind ihc not ice to ihe Stmo of Hpubl ic hearing i f the S t a t e takescorrective act ion satisf.ictorv 10 theAdministrator or

(2) Rescind the fmd:ng for which thenotice was given and promptly no t i fythe State of such rescission, or

(3) Uphold the f inding for whicli thenotire was given. In th i s event, theAdministrator shall revoke the StR' r ' sdecision that f i l t rat ion was not r cqu iu ' i lor revoke the compliance scheduleapproved by the State, and promulp.t ' r .as appropriate, with any appropriatemodifications, a revised f i l t ra t iondecision or compliance schedule andpromptly notify the Slate of such action.

(f) Revocation of a State's f i l t r a t i o ndecision or compliance schedule and/orpromulgation of a revised fi l t rat iondecision or compliance schedule shalltake effect 90 days after the Stale isnotified under paragraph (c)(3) of thissection.(FR Doc 89-15072 Filed 9-26-89: MS «m|•IUJMG coot