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# Envir

# anmental 

# Protection Agency

@ Printedon RecycledPaper

### 3B2sa” Federal Register 

## / Vol. 56, 

## No. 126 

## / Monday, 

### July 1, 

### 1991

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141,142 and 143



### RIM 2040-AA55

IFRL-3960-1 

### I
Drinking Water; National Primary Drinking Water Regulations; Monitoring for Volatile Organic Chemicals; MCLGs and MCLs for Aldicarb, Aldicarb Sulfoxide, Aldicarb Sulfone, Pentachlorophenol, and Barium

AGENCY: EnvironmentalProtection Agency (EPA).

ACTION: Final rule.

SUMMARY: In this notice, EPA is revising monitoring requirementsfor eight volatile organiccontaminants (VOCs) originally promulgatedJuly 8,1987. This change synchronizesrequirements for these eight VOCs with monitoring raquirements for VOCs promulgated on January 30,1991 (56 FR 3526). EPA is 

### also promulgating the MCLGs and MCLs for aldicarb, aldicarb sulfoxide, aldicarb sulfone,pentachlorophenol, and barium. This Notice also corrects errors and clarifies certain issues in the final rule promulgating 33 National Primary Drinking Water Regulations promulgatedJanuary30,1991 (56 

### EX 3526).

EFFECTIVE DATE: The amendments to 

### Q 141.6, paragraph (c) of the table in 

### fi 141.12. and 

### Q 141.62(b)(l)are effective July 1,1991. The amendments to 

### fi0 141.11(b), 141.23,141.24,142.57, 143.4(b)(12) and (b)(13),are effective July 30,1992. The revisions to 

### Q 141.32[e)f16), (25) through (27) and (46); 

### fi 141.50(a1(15),(b)(4),(bI(5) and (bl(6); 

### fi 141.51(b)!3); 

### Q 141.61(~)(2), (c)3, (c)(4) and (cI(26); 

### 8 141.62(b)(3)are effective January 1,1993.

The barium information collection requirements of 

### 0 141.23 are effective January 1,1993, if the information CollectionRequest is cleared by the Office of Management and Budget (OMB). If not, EPA will publish a document delayingthe effective date of the barium informationcollection requirements.Otherwise,the requirements will be effective when 

### OMB clears the request atwhich time a documentwill be published in the Federal Register establishing the effective date.

In accordance with 40 CFR 23.7, this regulation shall be considered final Agency action for the purposes of judicial review at 1p.m., Eastern time on July 15,1991. ADDRESSES: A copy 

### of the public
comments received, EPA responses, and all other supportingdocuments (including references included in this notice) are available for review at 

### the 

### U.S.EnvirenmentalProtectionAgency (EPA),Drinking Water Docket, 401 M Street, 

### SW., Washington,DC 20460. 

### For

access to the docket materials, call 202­ 382-3027 between 9 a.m. and 3:30 p.m. Any documentreferenced by an

### MRID number is available by contactingSusan Laurence, Freedom of Information Office, Office of Pesticide Programs, at 703-557-4454.

Copies of health criteria, analytical methods, and regulatoryimpact analysis documents are available for a feefrom the National TechnicalInformation Service (NTIS),

### U.S.Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll-free number is 8RO-336-470,local: 703-487­ 4650.
FOR FURTHER INFORMATION, CONTACT: A1 Havinga, Standards Division, Office of Ground Water and DrinkingWater (WH-550), 

### US.Environmental ProtectionAgency, 401M Street, SW., Washington,DC 20460,202/382-5555. General informationmay also be obtained from the EPA Drinking Water Hotline. 

### The toll-free number is 800/426­ 4791, Alaska and local: 202/382-5533.
SUPPLEMENTARY 1WFORMATION:

Table of Contents
I. StatutoryAuthority 11. RegulatoryBackground 111. Explanationof Today’s Action

A. VOC MonitoringRequirements
1.StandardizedMonitoringFramework 2. SamplingPoints 3. Initial and Repeat Base Monitoring

Requirements 4. Increased Monitoring 5. Vulnerability Assessments and Waivers B. Aldicarb, Aldicarb Sulfoxide, and

Aldicarb Sulfone 1.Aldicarb,Aldicarb Sulfoxide, and

Aldicarb Sulfone MCLGs 2. Aldicarb,Aldicarb Sulfoxide, and

Aldicarb Sulfone MCLs C. Pentachlorophenol 1.Pentachlorophenal MCLG 2. Pentachlorophenol MCL D. Barium 1. Barium MCLG 2. Barium MCL E. 1415Variance Option F. Analytical Methods G. Corrections to the January30,1991

Notice IV. Economic Analysis

A. RegulatoryImpact B. RegulatoryFlexibilityAnalysis C. Paper Work ReductionAct

1. StatutoryAuthority

The SafeDrinking Water Act (“SDWA’ 

### or “the Act”), as amended in 1986 (Pub. L. 99439,100 Stat. @2), 

### Rules and 

### Regulatidns

requires EPA to publish “maximum contaminant level goals” (MCLGs) 

### for contaminants which, in the judgment 

### of the Administrator, “mayhave any adverse effect on the health of persons and which [are] 

### known 

### or anticipated to

occur in public water systems” (section 1412(b)(3)(A)). MCLGs are to be set at a level atwhich “noknown 

### or anticipated adverse effects on the health of persons

occur and which [allow] an adequate margin of safety” (see section 1412(b)(4)).

At the same time EPA publishes an MCLG, which is a non-enforceable health goal, it must also promulgatea National Primary Drinking Water Regulation (NPDWR) which includes either (1) a maxim- contaminant level (MCL), or (2) a required treatment technique (section 1401(1), 1412[a)(3), and 1412(b)(7)(A)). A treatment technique may be set only if it is not “economically 

### or technologically feasible” to ascertain the level of a contaminant (sections 1401[1)and 1412(b)(7)(A)). An MCL must be set as close to the MCLG as feasible (section 1412(b)(4)). Under the Act, “feasible”

means “feasible with the use of the best technology, treatment techniques and other means which the Administrator finds are available, after examination for efficacy under field conditions and
not solely under laboratory conditions (taking cost into consideration)” [section 1412[b)(5)).NPDWRs also include monitoring, analytical and quality

assurance requirements,specifically, “criteria and procedures 

### to assure 

### a supply of drinking water which dependably complies with such 

### * *” maximum contaminantlevels 

### * (section 1401(1)(D]). Section 1445 of SDWA also authorizes EPA to promulgatemonitoring requirements.

11. Regulatory Background

On July 8,1987EPA promulgated NPDWRs for eight volatile organic contaminants (VOC rule, 52 FR 25690). On May 22,1989 EPA proposed VOC monitoring requirementsfor 10 contaminants and MCLGs and MCLs for 38 contaminants including aldicarb. aldicarb sulfoxide, aldicarb sulfone. pentachlorophenol, and barium. The MCLGs and MCLs for these five chemicalswere reproposed on January 30,1991 (56 FR. 3600) at different levels due to informationwhich was received and/or analyzed by the Agency subsequent to the May 22,1969 proposal.

The monitoring requirements outlined in today’s rule for the most part mirror (with several exceptions, asnoted below) the VOC requirementspublished



# 3

# 31987VOC 

### rule. This requirement serves to give early Indication that contaminationhas occurred before 

### a violation occurs. EPA acknowledges that false positives might rarely occur (Le., less than one percent of the time] with a detection limit of 0.0005 mg/l. However, we note that requirements in 

### 8 141.24 (fl(13) also allow the State to require confirmation samples for positive 

### or negative results. 

### In addition, the State has the option to delete results of obvious sampling errors. EPA believes that States have sufficient discretion 

### to address the issue of false positives through these provisions.

Another commenter argues that waivers will be difficultto obtain because of unreasonably low detection limits. EPA regulations do not allow systems which have detected 

### VOCs to receive waivers because even detecting contamination

### is evidence that the system 

### is vulnerable. 

### This contamination should be further examined by additional monitoring.

Several commenters objected to the provision which allows States to reduce the sampling frequency of systems which detect contamination. One
commenter believed that this determination should not be made for ground water systems until four quarters of monitoring have elapsed. EPA believes that the proposed requirement that the State determine the system is “reliably and dependably” below 

### the MCE is protective of health. The two quarter requirement is sufficient as a minimum standard but we note that there may be situations where additional monitoring (beyond the two quarter/four quarter minimum) will be
necessary to establish a baseline. In these cases, if the State does not make the “reliably and dependably” determination, systems 

### will be required
to continue to monitor quarterly.

5. Vulnerability Assessments and Waivers



### Most commenters agreed with the concept of vulnerability assessments and waivers particularly the provision 

### for a separate vulnerability decision by consideration of use and sus9ptibility. Several commenters noted aatthe shift of responsibility from States to water systems to conduct vulnerability
assessments could result in waivers being unavailable for small systems. Several commenters stated that additional guidance was necessary to ensufe systems know how to conduct vulnerability assessments.

As stated in the proposal, EPA shifted the responsibility to conduct vulnerability assessqents from States to water systemsbecause we believe that these assessments

### are part of the systems’ monitoring responsibilities. 

### In addition, previous comments indicated that State resource constraints precluded the conduct of vulnerability
assessments. Consequently, EPA shifted the responsibility to conduct vulnerability assessments to water systems. EPA agrees with the
commenters that additional guidance on how to conduct vulnerability
assessments is needed and is currently developing such guidance. This guidance will be completed and mode available to water systems and States prior to the compliance period which begins January 1,1993.



### Our goals are to efficientlyutilize State and PWS resources and to be consistent with Phase I1 monitoring requirements. EPA believes that today’s rule furthers these goals.



### B.Aldicarb,Aldicarb Sulfoxideand Aldicarb Sulfone

1.Aldiicarb, Aldicarb Sulfoxide and Aldicarb Sulfone MCLGs

On January 30,1991 EPA reproposed MCLGs for aldicarb, aldicarb sulfoxide, and aldicarb sulfone at O.o01,G.o01, and 0.002 mg/kg/day. The MCLG for each of the three chemicals wasbased 

### an a revised 

### RfD adopted in August 1990that reflected non-cancer endpoints of toxicity, cholinesterase inhibition (ChEI), and, for the parent compound (aldicarb),clinical signs in animals (soft mucoid stool and diarrhea) and humans (nausea, vomiting and diarrhea in some sensitive individualswere noted in epidemiological data). Cancer classification is Group 

### D (inadequate human evidence of carcinogenicity).

Public Comments

EPA has previously addressed the public comments received in response to the proposals of November 13,1985 and May 22,1989 in the Federal Register notice of January 30,1991 (56

### FR 3600). Four commenters responded to the January 1991proposal. One commenter argued that 

### EPA’s Rfe) of 0.0002 mg/kg/ day used in developing the proposed aldicarb MCLG is legally and scientifically unsupportable. In support 

### of this position, the commenter cited the May 23,1990 recommendation of the joint study group of the Agency’s Science Advisory Board and Scientific Advisory Panel 

### (SAB/SAP) that ChEI is
not an adverse effect and therefore should not be the basis of EPA regulation for aldicarb. One commenter advised that the Agency establish the MCLG and MCL for aldicarb and the sulfoxide metabolite based on the Haines (1971) human study. This cormnenter suggested 

### wing the

### NOAEL for clinical signs in this study, 0.05

### mg/ kg, and a 10-foolduncertainty factor
to establish the MCLG. 

### For aldicarb sulfone, this commenter indic<ated that the lowest dose tested 

### in the one-year dog feeding study (Hazleton Labs, 1987). 0.11 mg/kg/day. is the 

### NOAEL and should be used with a 10-fold

### UF to establish the MCLG for aldicarb sulfone.

Two additional commenters agreed with the position expressed by the first
commenter relative to the 

### SAB/SAP recommendation on ChEI 

### as only 

### a marker of exposure, and that the Agency should not lower the 

### RfD for aldicarb. However, one of these two commenters noted that the MCLG should be based

on child exposure.

A fourth commenter indicated that the reproposed MCLGs for aldicarb, aldicarb sulfoxide, and aldicarb sulfone, based on the revised 

### RfD of O.OOO2 

### mg/ kg/day, may not provide a sufficient margin of safety against acute toxic symptoms in the general population at levels aslow as 0.0011mg/kg/day.

The first commgnter also noted that establishing an MCLG based on ChEI is inconsistent with the Agency regulation for fluoride and silver. Response to PuSlic Comments

Aldicarb and aldicarb sulfoxide. The Agency reproposed an MCLG of 0.001 mg/l for ddicarb and aldicarb sulfoxide based on a revised 

### RD of 0.0002 

### mg/kg/ day (July, 1990], as described in the January 30,1991Notice (56

### FR 3604). This RfD was based on clinical effects and cholinesteraseinhibition 

### (ChEI) in animals and humans following exposure to aldicarb. The Agency sought public
comment on considering both clinical signs and ChEI in setting the 

### RfD and, in turn, the MCLG.

Many of the studies considered in the risk assessment for both aldicarb and aldicarb sulfoxidereported ChEI in exposed humans or animals. Consideration of blood ChEI as an adverse effect has been and remains controversial among the scientific community. ChE may be significantly inhibited in the blood without apparent signs of impaired function,histological damage 

### or other clinical effects in exposed individuals. Thefe are instances, though, where low levels of ChJ3 are observed along with clinical manifestations. A more detailed discussion of the levels of ChEI for the studies considered in the risk
assessment of aldicarb and its sulfoxide is given in the January 30,1991 Notice.

The Agency agrees with the public
comments in that blood ChEI can be considered as a biomarker of exposure.



# YHowever, 

### to be protective of public health, the Agency considers that ChEI

can

### not be totally discounted 

### in the risk
assessment 

### for aldicarb, aldicarb sulfoxide, and aldicarb sulfone. The Agency is currentiy evaluating the correlation between ChEI and clinical signs 

### of toxicity. If the conclusions of this evaluation alter the basis presented for t!ne MCLG in this notice, then the Agency will initiate 

### a process for determining whether the MCLG should be revised. Thus, after consideration of public comments, the Agency has decided to base the final MCLG for aldicarb, aldicarb sulfoxide, and aldicarb sulfone, on clinical signs. EPip 

### will continue to examine the relevance of using C&I in establishing anMCLG. Over a period of time this effort is expected 

### to resolve the questions related to the significance of ChEjl.

Because the controversy 

### has not yet been fully resolved, EPA developed an alternative approach for setting the MCLG, using clinical signs.

Since both the Agency-verified RfLl and the alternative derivation of the 'MCLGresult in an MCLG value of 0.001 

### mg/l, the Agency 

### is promulgating the MCLG atthis level. An MCLG of 0.001 mgll will be sufficiently protective of public health.

"he final MCLG of 0.001 mg/l is based



### on signs of clinical toxicity in dogs and humans exposed to aldicarb. The quantitative assessment stems from a no-effect level for clinical effects of 0.02 mg/kg/day as determined in 

### a 1-year dog study (Hazelton Labs. lac., 1988). At higher doses, effects such as diarrhea and soft stools were observed. The Agency has determined that these signs

are representative of clinical signs of toxicity, 

### In keeping with general Agency practice (56

### FR 35321, anuncertainty factor of 100was used to account for 

### a no-effect level from an animal study that considers intra- and interspecies differences in response to toxicity. 

### The resulting value, 0.0002 rnglkglday, is numerically the same as the Rfb) which considers both clinical effects and ChEI. This was adjusted by the assumption of



### a 70

### kg adult drinking an average of 2 liters water per day and a relative

source contribution of 20% to yield an MCLG of 0.001 mg/l.

The no-effect level of 0.02 mglkglday and resulting MCLG of 0.001 mg/l is supported qualitatively by 

### a controlled human study (Haines, 19711 and takes into consideration the observation reported in the Goldman study (1990). In the Haines study, no significant clinical effectswere observed in four healthy males given doses of 0.025 or 0.05 mgl kglday. A higher dose of 0.1 mglkglday resulted ilt neurological effects. The noeffect level of 0.05 mgfkglday wasnot used 

### as the sole basis for the MCLG because 

### of the limited scope of the study such that 

### a sensitive population may not have been studied, and the narrow range between the no-effect level and the effect level. Moreover, Goldman et 

### al. reported clinical effects at estimated doses lower than those reporkd by Haines.

Goldman el al. reported clinical ef'fects in humans (including women and children) following three separate incidents involving aldicarblaldicarb sul�oxidein California. Exposure to aldicarb sulfoxide from the contaminated watermelons and cucumbers were estimated to range from 0.002 to 0.08 mglkg body weight. A OW effect level for clinical effects was estimated at 0.082mg/kg. This study is
not used asthe sole basis for the MCLG, however, since the authors noted that the dosage calculations were uncertain and because of the wide range of human sensitivity demonstrated by these individuals. The authors relied on selfreports of food consumption, estimates of weight consumed and estimates of body weight.

Although each of the studies has limitations, as described above, the Agency has determined that &e dog and human studies taken together support the calculation of an MCEG of 0.001 ng/ 1.

In summary, the Agency is promulgating an

### MCLG of 0.001mgll 

### for aldicarb and aldicarb sulfoxide based

on a weight of evidence of clinical signs of toxicity observed in humans and animals.



### Aldicurbsulfone.

The Agency reproposed an MCLG of 0,002mg/L for aldicarb sulfone in the January 30,1991notice. This level was based on 

### a no-observed-adverse-effect level for ChEI in blood of 0.1 mg/kg/day snd an uncertainty factor of 300. Information on clinical effects in the study was not reported.

Aldicarb sulfone is considered less toxic than the parent based on 

### a 25-fold difference in acute toxicity; the 

### LD~o 

### for the sulfone 

### is 25 mglkglday compared
to the 

### LDSO for aldicarb of 1 mg/kg/day No data are available to determine clinical effects 

### or chronic toxicity associated with exposure to aldicarb sulfone. As stated above, the Agency is currently evaluating the correlation between ChEI and clinical signs of toxicity. Thus, the Agency will not use the MCLG of 0.002 mg/L proposed for the sulfone in the reproposal. Rather, to be protective of public health, the Agency is promulgating the MCLG of
0.001mg/L established for aldicarb and aldicarb sulfoxide,based on clinical signs 

### of toxicity as a surrogate for the sulfone. If the conclusions of the Agency evaluation of ChEI alter the basis for the MCLG, than the Agency will initiate a process for determining whether the 

### MCLG for aldicarb sulfone should be revised.

In summary, the Agency is promulgating an MCLG of 0.001mgll for aldicarb sulfone.

2. Aldicarb, Afdicarb Sulfoxide, and Aldicarb Sulfone 

### MCLs

The proposed MCLs for aldicarb, aldicarb sulfoxide, and aldicarb sulfone

were based upon an analysis of several factors including: (I]The effectiveness of the best available technology [BATgranular activated carbon) in removing aldicarb, ddicarb sulfoxide, and aldicarb sulfone 

### to levels at 

### or below the proposed MCLs of 0.003 mg/k (2) the feasibility [including costs) of applying 

### BAT 

### for large systems. EPA estimated that 

### hecost io remove aldicarb, al2icarb sulfoxide and aldicarb sulfone using GAC to be $10-14 per household and thus feasible; and (31 the performance of analytical methods as reflected iri the practical quantification level (PQL] fer each contaminant. In the proposed notice EPA stated that data from Water Saipply Studies showed that the PQLs 

### for aldicarb, aPdicarPJ sulfoxide. and aldicarb sul�onecould be
set at 0.803 ng/lby broadening the acceptance limits to 

### A%%.

The pivotal comments concerned establishing the PQL for aldicarb, aldicarb sulfexide, and aldicarb 

### sulfone. One conmenier noted that Water Suppay Studies *22-25 which were used to calculate the PQL did not "bracket" the proposed levels. This comrnenter noted that the lowest levels in Water Supply Studies *22-25 were 0.00947 mg/ 

### B for aldicarb, 0.00867 mg/l for aldicarb sulfoxide, and 0.00833 mg/i for aldicarb sulfone. Several commenters objected to 

## mil's adjustment of PQL acceptance limits to achieve lower MCLs. These
commenters noted that the usual Agency practice is to use % 20% or ri: 40% of the
true value. These comrnenters objected


### to the Agency's broadenh3 the acceptance limits to 

### +. 55% arguing instead that EPA should use a single Fixed acceptance limit.

After considering the comments, EPA Jecided to revisit the rationale on which the PQLs were based. As 

### a result, the Agency concluded that the elements of the rationale that involved extrapolating data were inappropriate for this compound.

EPA sei the proposed PQLs of 0.003 ,ng/l by extrapolating from the lowestIeveIs in Watm&pplg 

### Wes #22-%, to 

### tbe point &t Wh�B2% 

### pemenl!

### d the p&cipakhg 

### foborakwieswdd 

### be able



### to analyzewi&n; 

# +55 persen8 

### of 

### ths
true vakbe. 

### EPA USaQ

### tYs atmplation
twm 

### k.�wamse

### �he water %p& St& #&a5 &W�y 

### desigm

### did 

### not inelude the hvek

### of concern i.e, MCLGs of

## O.m% ad 

### OW qjl preposed 

### in the 

### bnwwy Nuhe

### f%FR 36~).

The existing Wster Supprsf SWies

were designedto provide data for
assessment 

### of laboratorypfomance
at levels of CORG- 

### whick were higher (Le., MCLGs 

### oEO M 

### mgli pmpsed in 

### NoverabeP I%& @Q

### FR 4fi986)and &ol and Q.W

## rngb ppsed 

### h May 1989 (54 FR ZZW]), 

### En thisease, the 

### levels

Fvaluated

### in 

### theWater 

### Supply Studies

1Jere above &e 

### tox.ied@ml levels 

### of ('omern &MKE E&) 

### braldiiarb,

a !dicarb 

### s&oxide 

### md 

### ddiearb rmlfoRe
3s propcrsedin 

### janmrjt 399%. 

### For this

reason we 

### dedded k~ use 

### an alternate procedure 

### for setting &e PQL 

### for :.Idicarb, which sets 

### the 

### PQL at five times the intedabmtory 

### methad detection 

### limit

# om, was first discussedin settingthe 

### MCL 

### for vinyl ChlQikhf52 25690,

## J& 1987). W S proeedure isused 

### ta 

### set thePQL when there is 

### not water supply study data at the level 

### of concern OHwhen the 

### usual praceedurewould 

### res& 

### in a 

### PQL which
poses a greater 

### tharr 1&4 

### cancer risk.

The ahficarb, aldkarb suhxide 

### and aldicarb 

### m&ne PQLs 

### were determined using the range of 5 to 10 times the IMDL. The PQb

### of O.W,0.004

### and 0.002 

### mg/l for aldicarb, 

### aldicarb sulfwide and aldicarb sulfone, respectively, ape based

on the lewer factor 

### af 5 

### times &e respeztive IM3X.s ti.e.,0.W.0- and 0.OOO3 

### q&. EPAhas previously stated (Le., 

### EDB (56

### FR 352611 that thause 

### of 5 times the 

### WDi. instead 

### of 1Qtimesthe MDL to set the 

### PQLmay.be appropriate when 

### ather emsiderations suggest the 

### PQL should be 

### lower [Le., 

### where there is

a lack 

### of performance evaluationdata at the level of concern 

### for a particular contaminant]. 

### In the 

### mse sf at$icarb and its metabolites, the Age~~y has decided to base the PQL ~15 times the 

### IMDL because 

### (a)it 

### is feasibleand @I) it is closer to the 

### MCLG 

### &.Ranthe 

### io multiplier,,



### The validatbstudy fopMethod 5a.z [the approved methad 

### for

### the ai&oarbs] providesevidencethat a 

### PQL of 3.Q

### -11
is 

### achievable f0r aldimrbi The design1 

### for 

### this study is cornpamble 

### Pa 

### that of tkeWater Sapply Studies

### &e.,wnknown concentcations, 

### magentpde water, colraborativet. 

### Tha lewd 

### of 0.W 

### mg/k (3.24 pg/1, was analyzedfor aldioarb 

### in the study and 

### dted in 

### gwd preoisisn 2nd acowacy with a mean lUtc0vex-y

### OE 3.26pgfl and a 

### standad deviatim 

### a� 0.33 pgP. Results

### d analy8esfix aldicarb sulfoxide 

### and 

### Ctfdia~h dine aIm 

### had good precision

### an& acewaw but 

### thft levels analyzed were at letrefs

### of 6.40

### and 8.44 pg/L respectively. EPA believes that these method 

### vafidation 

### resultsgive additional support�0~ he PQLs.

EPA recognizes that, at the PQL levels chosen, 

### s32ghdp less precision

### an$
accuracywill occnr. Huwwe~, EPA believes that it isappropriateto 

### aecept lessprecision 

### in order

### to 

### &ah mwe stringent levels 

### of con&& B-se 

### of the lack 

### of performance eva1b-n studies at the 

### MCLG, the acceptance 

### limits for aldicarb, aldicarlr sdfmide and aldicarb 

### sulf~ne wiu 

### he based on two standard deviations using

### Water Supply Study statistics. EFA 

### wili reevaluate this

### when it acquiresthe appmpriate data at levels 

### below or at the PQLs, frem ongoingWater Supply Study data 

### to assess "fixed tme.vaIue" acceptance

### limits. EPA afsobelieves &at the 

### precision and accuracy at these levels will improve after more use 

### of the relatively 

### new methodoIogy.

EPA has examined the health Fisk9 

### of setting �he MCLs above the 

### MCLGs 

### of
0.001mg/l. 

### Childrenare Bemost 

### sensitlvepopulation for these compounds. Howevers

### a child likely would not consume a 

### whole liter at one time. 

### More typically children consume water throughout the day and this would mjtigate against adverse 

### ef- at the 

### hfCLs and below. 

### The adverse effects of aldicarb 

### are thought to 

### be reversible within 4 to 6 hours at 

### higher levels 

### of
exposure. Therefore, EPA believes that the MCLs of 0+003 mg/l 

### for aldicarb,
0.004 

### mg/l 

### for aldicarb sulfoxide and 0.002 

### mgJl

### for aldicarb sulfone are protective 

### for chitdren. Until t�ie analytical chemistry and laboratory performance innprove, 

### EPA believes the 

### hfCLs 

### for aldicarb, aldicarb sukfaxide, and aldicarb sulfone are set at the lowest level feasible. Consequently. 

### for the reasons cited above the MU 

### fm aldicarb, aldicarb sulfoxide and a1dkarb sulfone are established atO.aF)3m&
0.004 mg/t and 0.002 

### w/I,resgectiveIy.


### C.

### Pentachlomphmoi

1. PentachtoropophenolMCLG

On lanu;try

### 3Di 199r. EPA pr0prtsed.m 

### MCLG 

### of zembased 

### on e 

### drinlting
water 

### contaminant

### dasclificatiand Category I 

### for pentacMomp8ed 

### (PCBf. This prepasa1 was based 

### on &e cladcaticrn 

### of 

### PCP as a 

### Class 

### ES: carckegen

### under EPA'w~ncm classification system 

### (Le.,

### probahta human 

### careinagenJ, WA, 

### inrea&hg the Bzclasaificatien. determined

### that there



# 6 is sufficieut

### evirhce

### of car&agenicitr for 

### pentaehbraphemlfnom animal: stdies.

### This deeisionw3s 

### qortedby the 

### ScienceAdwisoryi�har&im&ziL
1990. 

### TWB gcades 

### of peSge&omphtmtA (purified 

### mmdd 

### and technical grades)

### bo& inducedmultipk? tumm typm 

### at 

### differentdoseleveb 

### in malie andfemale mi-. Summary of Comments



### Three cwgaaizahns submitted
commentson the Asncy's ciarcinogen classification for PCP. 

### Alf 

### three
commentersbelieve that the carcinogenic evidence 

### from animal studies 

### is limited. These conrme&ers argued that 

### FCP should be CIassiSied in 

### Class C (with 

### an MCLG of 02mg/IJ: based 

### on a National Toxicology 

### bgmm bioassay which detected a 

### response

### im only one 

### species

### of 

### B6�3F1 mice.These
commenters cited other negativerodent studies. One comntercalcdeted the

cancer 

### risk and claimed that EPA overestimated 

### tHe came?

### risk by a factor 

### of 10.


### EPAs 

### Response to &e 

### Comments

After careful review of the CWUneRtS, EPA rea�firmed thatpentachhapheno1 should be classified as E2 carcinogen (probablehuman caxinogen]. The studies cited by the commenterswere previously considered by the Agency and no new infomation was-provided 

### by the commenter.

EPA's �32classification is based 

### on inadequatehuman data and snffacient evidence 

### of carcinogenicity in &malls: statisticaZIy signiEcant increases in &e incidencesof multipre blohgicdy significant tumor types @epatocelIular adenomas and carcinomas, adrenal medulla pheochromocytQmas 

### and' malignant pheochramocytomas, 

### and/or hemangiosarcomasand hemangiomas). in one 

### or 

### both sexes 

### of B6C3Fl mice using two diffkrent preparations

### Qf pentachlorophenol. 

### In additian, a 

### high incidence 

### crf two uncom0n 

### +.mors [kemangiomaslhemangi~~comas and adrenal medulla pheachrtlmocytomsl

was- observed with 

### bath preparationsB This classification

### is supported by mutagenicity data, 

### whieh pmvide some indication that PCP has ciastagelpie potential,

Sever& studies in 

### rodents cited

### by cclrnmenterswere 

### unable fe 

### dernonshte the caPeinoge&ity 

### of PCP. Howaver, these studies 

### wem 

### alljudged 

### hy EPAtb. be limited 

### and not 

### usefirl

### for drawing

CO~C~US~OFIS concerning

### the carcinogenicity

### d PCP. 

### "he sbdy repocted 

### by hea etiel. f3%?] 

### used 

### or&

onede withan insuffjcient

### nmbm

### d animals, 

### The study 

### by Catiilina 

## @m)

### ’Federal Register 

### Vo4. Si, 

## No. 126 

## 1 Monday, 

### July 1, 1991 

## / Rules 

### and Regulatsons 

# sizsa

__ used an inappropriate route of administration with only one dose, and there was excessive mortality. The study by Schwstz et al. (1978)used an inadequate nimber of animals, and it is


### not clear whether the maximum tolerated dose 

### (MTD) had been met. Finally, the dose level, frequency and duration of exposure were limited in the study by Bontwell and Boach I1959).

In quantifying the cancer risk, EPA used pooled tumor incidence 

### of hemangiosarcoma/ hemangioma, pheochromocytomas and liver neoplasm in the femalemice to obtain a slope factor 

### of 0.12 per [mglkg)/day. This slope factor results in a unit 

### risk of 3 

### x 

## lop6 per [pg/lf.This means an adult
person who 

### drinks 2 liters of contaminated water per day for life (70 years), is expected 

### to have an upper bound cancer risk of 3 in a million at a concentration of 1pg/ 1 water. Thus, at the proposed MCL of 1 pg/l, the upper bound risk of cancer is within the to HPrange. The statement in the January 30 Federal Register [page 3808) that “A

cancer unit risk estimate 

### of 4.76 EX8 caseslperson (pg/1] 

### jyr’” should be deleted.

EPA Conclusion

EPA reaffirms the Class B2 classificationfor pentachlorophenoland places pentachlorophenolin drinking
water contaminantCategory

### I. Consequently, the MCLG is set at zero,

2. PentachlorophenolMCL

The proposed MCL for pentachlorophenolwas based upon an analysis of several factors including: (1) The effectivenessof the best available technology, granular activated carbon, in reducing influent concentrations to the proposed MCL of O.@X mg/l 

### or less: [2) the feasibility {includingcosts) 

### of applyingBAT for large systems at approximately$10 per householdper year; (33the performance 

### of available analytical methods 

### as reflected in the PQL. Data from Water Supply Studies #22-25 indicated that the PQL could be established at 0.001 mg/l with an acceptance lit of 

### = 50%; and (4) caparison of the individuallifetime carcinogenicrisk of 3 

### x W-ofor the 

### MCL to EPA’s target risk 

### range of 10-4 to EPA requested comment 

### an whether the MCL should be established
at 

### a level below the risk Ileuel.

EPA received numerous comments on the PQL. Commentersnoted (1)that EPA failed to identifythe proceduresit used to derive fhe 

### .PQk (2) that EPA underestimated the analytical variability at the 

### MCL: and 

### [a) that the propwed 

### MCL will yjeld unacceptably large laboratory performance variability. Several organizations commented on the question 

### of whether the PQL should be established at a level below the 10/ -6/ 

### risk range. These
cornmenters stated that health risk should not be part of the PQL determination. Several commenters noted that EPA has yet to establish a consistent approach to establishing PQLs. These commenters stated that the PQL should be determined independently and not set to achieve an MCL that is within EPA’s acceptable risk range. Several commenters stated that they do not favor development of MCLs below the 10/ -61 risk range. One
commenter argued that EPA should establish the MCL at the 101-6l risk
range (Le., 0.0003 mg/l).

The procedures EPA used to establish the PQL 

### for pentachlorophenolare similar to those used in the PQL
assessments for prior regulated contaminants,i.e., the eight VOCs on July 8,1987 (52FR 25690) and 33 pesticides, VOCs and ZOCs on January 30,1991 (56 

### FR 35261. The procedures EPA uses to establish PQLs are described in the July 8,1987Notice on pp. 25699-25700. EPA believes that its establishment of the pentachlorophenol PQL is consistent with its policy as articulated in those prior Notices,

As stated in the January 1991 proposed rule, 

### EPA in May 1989 estimated the PQL to be 0.001 mg/t which was based on 10 times the 

### IMDL, because of the lack of Water Supply Study data. EPA haspreviously used this estimation technique for several Contaminants. This level is typically a higher level than the MDL and represents a practical and routinely achievable level with reasonable certainty that the reported value is reliable. EPA subsequentlyreceived and analyzed Water Supply Study data to determine the proposed PQL with accompanying acceptance limits.

Based on our reanalysis of the Water Supply Study data, the Agency concluded that the data did not support the proposed PQL of 0.0001mg/l. 

### This

was evident by the erratic laboratory performance for concentrations that

were less than O.o001mg/1. Consequently, a revised PQL was assessed 

### using the procedures described above. 

### ThepentachlorophenolPQL is based upon the results of EPA and State laboratory data 

### from Water Supply 

### Studies #22.25. EPA calculated the ‘50 percent acceptance limits (Le., true value of fiesample *50 percent) based upon these Water SupplyStudy statistics. The “plus 

### or minus percent .of the true valwe” acceptance limitswere derived taking 

### into considerationthe expected precision and accuracy.This range closely approximates 

### the 95 percent confidence limit estimated from the regression equation determined from the Water Supply Study data. EPA believes a PQL 

### is achievable if the Water Supply Studies show that more than 75 percent 

### of the lgboratories are within the target range. In the case of pentachlorophenol,the PQL was 

### set at a concentrationwhere at least 75 percent of the EPA and State laboratories were within the specifiedacceptance range. A plot 

### of the percent 

### of laboratories passing [within the ”50percent acceptance range) versus true concentration of the samples demonstrated that the PQL should be set at 0.001mg/l. EPA subsequently included data from Water Supply Studies e26 and #27 in its analysis. These data confirm that concentrations equal to 

### or greater than the PQL 

### of 0,001 mg/l with an acceptance limit of +50 percent provides a performance target for laboratories that is achievableby 75 percent of the 

### EPA and State laboratories.

Severalcommenters noted that a ‘58 percent acceptance limit will result in unacceptable analytical variability
among laboratories.These commenters argued that EPA must establish a lower fixed acceptance range (i.e., +20%

### or & 40%). Though EPA agrees with these
comrnentersthat a single fixed acceptance limit is desirable, EPA has 

### not established these limits because (1) many of the methods are relativelynew and require sophisticated equipment and highly trained analysts which still results in variable labaratory performance and (2) the analysis 

### of Water Supply Study data demonstrates that laboratory performance can-

### in fact
vary 

### for some of the contaminants.As laboratories gain experience with the instrumentationand methodology,EPA anticipates improvements in laboratory performance. EPA 

### is continually evaluatingongoingWater Supply Study data asit b-comes available. These evaluationshelp determine whether the acceptance limits 

### for regulated contaminants should 

### be amended as laboratory performance improves.

As indicated previously, several
commenters stated that they 

### do not favor establishing

### MCLs below l0/-6/ 

### Pisk 

### This view is consistentwith the Agency’s 

### policy of set#in;g 

### drinkhg
water standardswithin the 10/ -41 to 

## la/ -6/ lifetimerisk range. 

### In response to the commenterwho supported setting the MCL for PCP at O.OOO3 mg/l [i.e., 10/ 

### -a/ lifetimerisk), we note 

### this regulatoly level Is not feasible at this time because it 

### is 

### less than the 

### PQL of 

## n.ooi mg/l.



# 3

### D.Bariunr

### Federal Re@ster 

## 1 Vcrl. 56, 

## No. 126 

### J Monday, July 1, I991 

### J Rules 

### and fegulakions 

### 3M73



### -

In 

### 8 141.23[k][5)(ii], the second nitrate in the table 

### with an acceptance 

### Emif of percent, 2 0.4 mgliis changed to nitrite 

### kl5 percent 

### 2 6.4 mg/l.



### Revisions 

### to 

### 0 141.23 Inorganic Chemical Sampling and Ana1ytim.l 

### Requirements inadvertently eliminated inorganic sampling 

### ad analyticaj requirements

### �or

### the 9 inorganics listed in 

### 8 142.11. EPA is reinsertingthe previous inorganic monitoring and analytical requirementsby adding paragraphs 

### (1) through (9)to 

### 8 14'1.23 (previously 

### 8 181.23 (a) through [e)).This cometion has the effect 

### of retaining 

### the previous inorganic requirements

### for cadmium, chromium, mercury, nitrate, and selenium lentilJuly 30,1992; 

### for barium 

### untilJamary 1,1993; andbeyond July 3Q,l992 

### for arseak. Any alternate test procedures previously approved 

### *mder 

### 3 241.27 

### for 

### both inorganic and organic contaminants continue to be efhtive until July 30,1992 and January 1.1993, 

### for barium

in 

### 0 141.%(e], Method 505 can alsobe used to analyze 

### �orendrin and is added
to the Est 

### of ameptable methods.



### In 

### 3 P41.Z4(h)(B)?.he sentence "after a 

### muximum 

### dffow qcarterly samples show the system is in compliance * * *" is changed to read "After a 

### minimum -of fom qtlartedy samples &ow the system is in compliance * li *" (emphasis added). 

### The reference 

### to paragraph (h](12)is changed to 

### QW%l).

In 

### 5 141.24{h){11E)(iv)toxaphene is added to the list of'contaminants which

can be analyzed using EPA Method 508.

In 

### 8 141.24(h)(lS)[i) the reference to paragraph @]{I31 is changed

### to paragraph 

### ihfllit),

The labratory certification sequireme& for the pesticides

### were not 

### ificluded in&e final 

### de. In 

### 0 14224{h)[19] EPA 

### is inchding laboratory

### certification requirements. The perfurmawe requirementswe discushied tisted 

### on paa- 3550 to 3552 

### of&e January %I, KWl Notice. In 

### 0 141.62[b) 

### the hrIct fer 

### fluorde is changed from 4 

### mgll to 4.0 mg/l.



### In 

### 8 141.57(b)the referenceto 

### 0 141.5qh) should be changed to 

### 8 241.62&].

In the footnotes

### to

### 9 143.4 ll2) and (13) 

### the updated versions 

### ofthe methods ~h~uid have been cited. 

### In footnote

### p,

cMltand.lsrpr 

### EPA Method 200.7,

### version 3.1,April 1990 

### is changed to version 3.2, August In footnote 5, 

### EPA Method 200.8, version 4.1,March 1990, is changed to version 4.3, August 1990;

### in footnote 6, 

### !&PAMethod 200.9, version 1.0,

### April 1990,is changed to version 1.1, August 199Q.

In 

### 8 143.4112)a later version of the method is dted. EPA changesMethod 

### I305i-84 

### to Method I-305i-85.

In 

### 8 143.4(13)a later version 

### of the method is cited.EPA changes Method 

### I372l3-84 tQ E3720-85.
IV. bdc Ady&s
Executive Order 12291requires 

### EPA and other regulatory agencies 

### to perform

a regu1atory impact analysis 

### (RIA] �or all ''major'' regulations,which are defined as those regulationswhich impose an annual cost to the economy 

### of$loo million 

### or more, 

### or meet other criteria. TheAgency has determined that the proposed rule is a minor rule �OF purposes 

### of the Executive Order.This regulation has been reviewed 

### by the Office 

### of Management and Budget as required 

### by the Executive Order and any wmments they make 

### will 

### be available in the publjc docket.

In accordance with the Executive Order, the Agency previously conducted

an assesslll(?llt of the benefits 

### andcasts 

### of regulatory alternatives aspart 

### of

### the Phase 

### II rule which 

### was promulgated

### in 

### the January30,2991

### FedadRegister. This assessment 

### in the Phase 

### II rule 

### determined the impacts

### of this regulation as part 

### of thePhase 

### I1 rule and consequentlythese impacts are uot separately reconsidered in 

### thisa~tice.



### A.

### Regziktmy

### �mpact
EPA's analysis conducted under the proposed 

### mie �or38 contaminants 154 FR 22062, May Z2,19�@ indicates that approximately 378systems 

### would violate the aidicarb 

### MCt,

### raf 0ioo9 mg/i based on 

### the uncertainty 

### in &e data base. 

### EPA does notbelieve 

### MCLs 

### of
0.004mg/l 

### for aldicarb sulfoxide and 0.002

### mg/l 

### for aldicarb sulfone will change 

### this -timate. An additional 8z systems

### would 

### vMab 

### M a fo? pentachforophend.

One corplmentm.@vidd%&ornatian disputhg

### EFWs estimate 

### of the 378 systems

### whkhmukd 

### violate the

### MCb for

### aiditarb,a4dkarb sulfoxideand

TA5LE 1 .--REGUMTORY $MfACT 

### -
aldicarb sulfone.This cornenter noted the relative 

### lack of o~currence data 

### to estimate regulatory impact. 

### This commenier assumed 1% 

### of the systems (654systems)would exceed the 

### MGL for aldicarb which isalmost double the 

### EPA estimate. EPA acknowledges the uncertainty in determiningthe regulatory 

### impact and stated in the Proposed Notim that %if&% of its estimate 

### of 378 

### systems 

### (I@ to

### 567) systems may violate the 

### MCL. Though it is conceivablethat 654 systems may violatethe aidicarb 

### 1Ww,-EpApoints
out 

### that 

### ihe regentlycompleiedNational Pesticide%mey did 

### not detect 

### ddicarb in any 

### -well at beis 

### exceeding-~.WO?l Wll.

Severalcornmienters stated that 

### EPA should consider 

### the impact 

### uf these regwiatosy requirements on the collateral effectswhich 

### trickle down 

### through other regulatory programs 

### such

as Superfund,

### the Clean Air Act 

### fCaA],
stream water quality standards under the Clean Water Act and requirements 

### under the Resource Conservationand Recovery Act IRy=RA3. WileEPA acknowledges that these secondary impactsmay occura the purpose 

### of today's action is solelyto establish drinkingwater standards that public
water systems mustcomply with. Conseguenily,

### EPA does not consider the cost 

### ofsecondary impacts

### wMch
may occur under the CAA, Super�und,

### or 

### RCM.One cornmenferalsosoted that these secondary impacts also affect the
water supply industryby increasingthe
waste and disposal mts 

### of treatment. EPA is aware 

### of this 

### issuea d 

### di$ include 

### &e cost 

### ofdagosa3.inthe RegulatoryImpact

### hlysis accompanying.&e 

### Jmaary3i&1991

### �hi rule.

As stated

### ~mlier, 

### EPA did not racon&& .themsts

### far the 

### pnyposed 

### VOG inanizoriagq&ernients because 

### thosecostsl#erewwinhEm3 Phase-I� 

### d egrPwnrlkgafed an &wmry 30, 1991.Tibe rostsa�bday!a

### VOC monitor@ reqakemmts

### have virtually

no impact on the total cost of 

### VOC mwitoring primarily bemuse 

### a single analytical method can analyze a m of contaminants. Samplingfor all VOC contaminants can

### be rondnd et &e

sametine.

Annual Typical tf@net'+wSystemsin

. treatment 3 cost 4 'UiotatiOa : (smiwion,yr) 'Small% ^Mediums ' ~p.4

.,
i' Aldi~&,&~k~~~~lb~id~~



### .................

# .....-....-.........-.. 

### _.... &&n!+.;-- 

### ........_..- ...A 37% i W) 

### ae. +*a. PentilcMM.ophenol



### ...................................................................................................... 625 $1 0 3s

I ..19

### 36274 

### Federal Register 

## / Vol. 56, 

### No. 126 

## / Monday, fuly 

### 1, 1991 

## / Rules 

### and Regulations

TABLE 1 .--REGULATORY lMPAGT-COntinUed

Annual Typical HH 1 treatment cost/system/year
Contaminant Systems in treatment cost violation ($mi,lioniyr) Small Medium Large

Barium



### ...................................................................................................................................................... 0 0 '$230460 '$54-160 '$26-110

I HH=houwhold.

Small system serving 25-100 people. Medium system serving 10,000-25,000 people. For Barium medium system serves 3,300-10.000 people. 

### * Large systems serving more than 1,000,400 people.

Cost dependent upon BAT chosen.

We estimate that approximately 280,000people will experiencereduced
exposure to aldicarb, aldicarb sulfoxide and aldicarb sulfone. Approximately 960,000people will have reduced
exposure to pentachlorophenol.



### E.RegulatoryFlexibility

### Analysis

The Regulatory Flexibility Act requires EPA to consider the effect of regulations on small entities. 5 U.S.C.
602 et seg. If there is a significant effect



### on a substantial number of small systems, the Agency must prepare 

### a Regulatory Flexibility Analysis which describes significant alternatives which would minimize the impact on small entities. An analysis of the impact 

### on small systems due to the MCL for aldicarb is includedin the RIA which supported the final Phase 

### XI rule promulgated January 30,1991. The Administrator has determined that the proposed rule, if promulgated, will not have a significant effect on a substantial number of small entities.



### C.PaperworkReduction

### Act

The information collection requirementsin this rule have been submitted for approval to the Office of Management and Budget (OMB) under the PaperworkReduction Act, 44 U.S.C. 3501 et seq aspart of the information collectionrequirements supportingthe final Phase 

### I1 rule on January30,1991. The information collection requirements

are not effectiveuntil 

### OMB approves them and a technical amendment to that effect is published in the Federal Register.



### List 

### of Subjectsin 40 

### CFR Pw-ts141,342, and 143

Chemicals, Reporting and recordkeepingrequirements,Water supply, Administrativepractice and procedure.

DatedJune 17,1991.
William K. Xeilly, Administrator,EnvironmentalProtection Agency. For the reasons set forth in the preamble, title 40 of the Code of Federal Regulations is amended as follows: PART 141-NATIONAL PRIMARY DRINKINGWATER REGULATIQNS

1.The authority citation for part 141 continues to read as follows:

Authority:42U.S.C. 3Wf, 300g-1,3oOg-Z, 300g-3,300g-4,300g-5,300g-6,30Oj-d and 300j-9.

2. 

### In 

## 4 141.6, paragraph (a)is revised and paragraph (8)is added to read as follows:


### 8 141.6 Effective dates.

(a) Except asprovided in paragraphs (b) through (8)of this section, the regulations set forth in this part shall take effect 

### on June.24,3977.



### * * * * *

(8) The regulations contained in Section 141.8,paragraph (c) of the table in 14.12,and 141.62@)(1)are effective July 1,1991. The regulations contained in 

### 04 141.11(b),141.23,141.24,142.57(b), 143.4(b)(12) and (b)(13),are effective July 30,1992. The regulations contained in the revisions to 

### 88 141.32(e)(16), (25) through (27) and (46); 141.50(a)(15), (b)(4),(bI(5) and (bl(6); 141.51(b)(3); 141.61(~)(2), (c1[3), (c)(4)and (c)(l6); 141.62@)(3)are effective January 1,1993.

3. Section 141.11is amended by revising the introductorytext of paragraph (b) to read as follows:



### 0 141.11 Maximum contaminant levels for inorganic chemicals.'

* * * * *

(b) The Maximum contaminant levels for cadmium, chromium, mercury, nitrate and selenium shall remain effectiveuntil July 30,1992; the maximum contaminantlevel for lead shall remain effective until December 7, 1992;the maximum contaminant level for barium shall remain effectiveuntil January 1,1993.



### * * * * *

4. In 

### 8 141.12, paragraph (c)in the table is revised to read as follows:

0 141.12 Maximum contaminant levels for organic chemicals.

* * * *

. milligrams 

# !

per liter

(c) Total hihalomethanes (the sum of the

concentrations of bromodichloromethme, dibrornochlorornethane, tribromomethane (bromoform) and trichloromethane (chloroform))



### .................................

* * * * *

5. Section 141.23 which was published January 30,1991. (56FR 3528) and which will become effective July 30,1992, is amended by revising paragraphs (a)(4)(i) (excluding the table) and (i)(l);revising the table in (k)(l);revising paragraph (k)(z); revising the table in (k)(4); revising the table in (k)(5)(ii); and adding paragraphs (11, (m),

### In], 

### (01, [PI, and (9)to read as follows:



### 0 141.23 Inorganic chemicalsampling and analytieal requirements.



### * * * * *

(a) * * * (4) 

### * * * (i) If the concentration in the composite sample is greater than or equal to the detection limit of any inorganicchemical, then a follow-up sample mmt be analyzed within 14day;s from each samplingpoint includedin the composite. These samples must be analyzed for the contaminants which

were detected in the composite sample. Detectionlimits for each analytical method are the following:



### * * * * *

(i) * 

### * * (1) 

### For systems which are conducting monitoring at a frequencygreater than annual, compliancewith the maximum contaminantlevels for asbestos, barium, cadmium, chromium, flouride, mercury, and selenium is determinedby a running annual average at each sampling point. If the average at any sampling point is greater than the MCL, then the system is
out of compliance. If any one sample would cause the annual average 

### to be exceeded, then the system is out of oompliance immediately. Any sample below the method detectionlimit shall 0.10Reference{Method No.) Contaminant Methodology �PA ASTMP SMa

i ufos 

## .--.._.-.._.. 

# I Bansmission Etecmnmoscopy~ ........_...._I__.-._.



## ...........

Chromium



### .............................



# . .......

1on chramatography



### ...................................................................................... 300.0 Nitrite

### ......._..._..._-....-.-.s$em@mmttiC"



## ...................................... 

## .l..-l--..l....--....--: 354.1 Autmm6d

# -

ieduction._....-.._._.._._l_l..__.I.I._._.... 359.2 D3867-SO

~ 418F Manual cadmirrrn reduction



### ................................................................... D3867-90 418C
: lon chromatography



### .................................................... 

# . .- 

### .......... Selenium



### ............................ : Atomic aboorption:gaseous hydride ._.__....l...l....-_..__I__._.....- Atoniic absorpaion; fwmete&iaique............_.l-....l.....Y-ll-.-..........-. D3859-m ' 304'

Metho& oi Chemical Analysis of Water and Wastes," �PA M i Witoring and Support laboratory. Cincinnati OH 45268 fEW4-%33~4-79432@, March 1983. Available from OFKlWcations, CEFN. EPA. Cinckwati, OH 452fXL 

### * Annual Rmk of ASWstandardg, Vd 11.01 Arnmban Societyfor Testing and Materials, 1916 Race Street, Phl@eiphia, P;P 19103. "Standard MethodsfDr the Emmination of Water and Wastewater: Wth edition. Amemin Pub!ic HealthAssoctahon. Amencan Water Wwks AssociatiDq Dlprrrer PoMitionControl Fsderatiwr, 1985. QWertmd§.(nrc?eter~ of Inorganic Subtances in Water and Fluvial t+diienF." Techniiues of Water-Resources Investigations of the US. Geological Survey Books. ChapW Al. 1989 Opeo-Ae Repwt 85-495. Wailable Wm OpeMile Smces section, Western LWriWbo n Brench,US. Geoloeicaf Survey,MS 306 Box 24525. Denver Federal 

### cent;v,Denver, CO 80225. "Orjon ChidetC W%ter and Was?6water Analysis" Form WeWwG/5880 p. 5 1985. Orion Research, Inc.. Cambridge, Mk 2Q0.7A ''~n~~Coy!d PLaSrnaAtornic E-ission Analysis of &g Wker," Appendm to Method 200.7, March, 1987, US. EPA, EnvironmentalMonitodng and Support Laboratory, Cinmnati, DH 45p68. The additicht of 1 mL af 30% KO, to each $00 mL of standards and samples CreqUkedMore analysis. Prior to dilution of the Se caiibratiq standard,add 2 mL of 

### 9% HIG for each 100 mL of standard. 

### * ''Adytical +.Whod Iw Determination of Asbestos Fibers in Water," EPA-600/4-83-043, september 1983, USEPA, Ein6ronmental Research Labwtw? Ath�?ns.GA 30813. ' 10"Waters13+f++hdforthe ion of NWe/FBltratein Water Using SingleColumn ton Chromatography. Method B-1011, Fjrmipore Corporafiorl, Watws ChrQmatography Owson, 34 Maple SzkI, MA 01757. fw app.cwed anatvticel pIocedurestor melab, the technique applicableto total metatsmast be used.

Public HeaZthAsaociatiow kmeri~an Water Works Asnociation.Water hWuiution Confro1Federation 1985. Techniquw cd Water-Resources hvevestipatian of
the United StatesGeological Survey, Chapter A-2 "MethodsforDetermiantionofhorganic Subdart- in Water ilnd Fiuvial Sediments," Beuk 5,1979. Stock #014Mll-03177-9. Available from dithiocarbamate;

### or Method 2oo.TA 

### Inductively Coupled 

### Plasma Technique 5.

* e * * *

[M41 

### * *

Superintendeatwf Docllmtnzs, US. Gove-n? printing Office,Wa&ngh3&3, DC 204G2 Annual EO& ofAWMStandards, part31 Water, American SocietyhrTeshgand&&id& 1918RaceStEeetPhiiadeiphia,Peansylwatpia39l@3. Appendix toMe&od 200-7,Mad 1987,US. EPA, Environmental MoaitoringSystems Laboratory, CincirmatbOH~%%ZI;

1 T,me Prerenrative

Apbestss



## ............................................. I..., 

## .........

## . 0301, 4°C

I

### ....... ^

### ................................. 

# -

'-......-..-.----..I....­ cadmium 

### '...-..-.-...-.-..-.--..-.....-.. ....

# - CWI HOs Ec pH <2



### .................................

Chromium 

### *..- 

### .....-.

## ---.--

................................ 

### ... Don WOS to pH <2



### ................................. rCon HOJ to pH <2



### .................................. Fluorii(e



### .......

## --...-

................ 

# -..-..-............-... : #one



### .. 

### ........................... . 

### ......................... 

### kw



### .................................................... 

# . W-tlcx to pW <2



### .................................. Myhate: CMOrit't@d 

### .-

.............................................. Cwf. 4%



### ............................................. Non-chlorinated



### ........................................... ConHpSOIto pH <2



### .............................. Nitrite



### .................................................................... Cool, 4°C



### ................................................... 

# t container

### *

P UG



### ............... i

### ..................................... 

### :
P DT G



### ......... 

### ......................................... Per G



### ................................................ P OT G



### ................................................ ,pw G



### ........................................... P or G



### .............................................

..

P or G



### ...................................................... 28 days. P or G



### ....................................................... i 14 days. P or G



### ........................................................ 48 hours.Contaminant 

## I Preservative 

## I Contahr 

## I Time'

Selenium 1

### ............................................................ Con HW to pH e2



### ............................... P or G



## ........................................................ 6 months.

(5) * 

### * 

### ' [i) 

### * * (ii) * *

Contaminant 

## 1 Acceptance limit

Asbestos



### ............................. 2 standard deviations based on study statistics Barium



### ................................. 3~15% at 20.15 mg/l Cadmium



### ............................. t20% at 20.002 mg/l Chromium



### ........................... *15% at 2 0.01 mgil Fluoride



### ............................... *IO% at 1 to 10 mg/l Mercxy;



### .............................. t30% at zO.0005 mg/l Nitrate



### ................................. *IO% at 20.4 mg/l Nitrite



### ................................... t15% at 2 0.4 mg/i Selenium



### ............................. f209b at 20.01 mgll question, exceeds the maxfmsm contaminantlevel, the supplier 

### of water shall notify the State pursuant to $ 141.31 and give notice to the public pursuant to $141.32.Monitoring after publicnotification shall be at 

### a frequency designated by the State and shall continueuntil the maximum contaminant levelhas not been exceeded in two successive samples 

### or until a monitoring schedule as 

### a condition to 

### a variance, exempticln 

### or enforcement action shall become effective.



### [o) The provisions of paragraphs (m) and 

### (n) of this section notwithstanding, compliancewith the maximum contaminantlevel 

### for nitrate shall be determined 

### on the basis 

### of the mean 

### of
two analyses. When 

### a Ievel exceeding the maximum contaminant level for nitrate is found, a second analysis shall be initiated within 24 hours, and if the

mean of the two analyses exceeds the maximum contaminant level, the supplier 

### of water shall report his findingsto the State pursuaxit 

### to 

### 3 141.31 and shall notify the public pursuant to 

### f 141.32.

(p)

### For the initial analyses required by paragraph 

### (1) 

### (I], (2)or (3) 

### of this section,data 

### for surface waters acquired within one year prior to the effective date and data 

### for ground
waters acquired within 3 years prior to the effective date of this part may be substituted at the discretion 

### of the State.

(q)Analyses conducted to determine compliance with 

### 5 141.11 shall be made in accordance with the following methods, 

### or their equivalent as determinedby the Administrator.
(1)Arsenic-Method 206.2, Atomic Absorption Furnace Technique; 

### or Method 1 206.3,

### or Method D2972-88B

1 "Methods of Chemical Analysis of Wa!er and Wastes," EPA EnvironmentalMonitoring and SupportIhboratory. Cincinnati,Ohio 45288 [EPA61N!&W20), March 1983. Available from ORD Publications. CHU.EPf\, Cincinnati, Ohio 45268,For approved analytical procedures for metals, the technique applicable to total metals must be used.

2 "Standard Methods for the Examinationof Water and Wastewater." 16thEdition. American Public Health Association,American Water Works Association,Water Pollution ControlFederation,
1985. 

### or Method 2 307A. 

### or Method 3 I-1062­ 85,Atomic Absorption-Gaseous Hydride: 

### or Method 1 206.4, 

### or Method P-2972-88A, 

### or Method 307B, Spectrophotometric,Silver Diethyldithiocarbamate;

### or Method 200.7, Inductively Coupled Plasma Technique.
(2)Barium-Method 208.1 

### or Method 308,Atomic Absorption-Direct Aspiration; 

### or Method 208.2, Atomic Absorption Furnace Technique; 

### or Method 8 200.7. Inductively Coupied Plasma Technique.
(3) Cadmium-Method 213.1 

### or Method 

### D 3557-78A 

### or B, 

### or Method 310A,Atomic Absorption-Direct Aspiration; 

### or Method 213.2 Atomic Absorption Furnace Technique; 

### or Method 8 200.7,Inductively Coupledd Plasma Technique.
(4) Chromium-Method 218.1 

### or Method 4 

### D 1687-77D3, 

### or Method 31&, Atomic Absorption-Direct Aspiration;



### or Chromium-Method 1 218.2 Atomic Absorption Furnace Technique;

### or Method 8 200.7,Inductively Couple Plasma Technique.
(5)Mercury-Method 1 245.1, 

### or Method 4 I)-322389,

### or Method 320A, Manual Cold Vapor Technique; 

### or Method 1 245.2, Automated Cold Vapor Technique.

(6) Nitrate-Method 352.1, 

### or Method 4 D-992-71, 

### or Method 353.3,



### or Method P-3867-79B, 

### or Method 4186, Spectrometric,Cadmium Reduction; Method 1 353.1, Automated Hydrazine Reduction;

### or Method 353.2,



### or Method 4 D-3867-79A, 

### or Method 41&F, Automated CadmiumReduction.

a Techniques of Water-ResourcesInvestigationof the United States Geological Survey, Chapter A-1, "Methods for DeterminationofInorganic Rdbstancesin Water and Fluvial Sediments," Book 5,1979, Stock #02pOo1-03177-9. Available from Superintendent of Documents, U.S. Government Printing OEice, Washington,DC 20402.

4 Annual Book of ASTM Standards. part 31 Water, American SocietyforTesting and Materials.
1976Race Street, Philadelphia. Pennsylvania 19103. '[Resewed&

8 "Inductively Coupled Plasma-Atomic Emission SpectrometricMethod for Trace Element Analysis of Water and Wastes-Method 200.7" with Appendixto Method 200.7 entitled, "Inductively Coupled Plasma-Atomic Emission Analysis of Drinking Water." March 1987. Available fromWA's EnvironmentalMonitoring and SupportLaboratory. Cincinnati,Ohio 45268.(7)Selenium-Method 270.2, Atomic Absorption Furnace Technique: 

### or Method 1 270.3; 

### or Method 1-1667-85,



### or Method 4 D-3859-79, 

### or Method 303F, Hydride Generation-Atomic Absorption Spectrophotometry.

(8)Lead-Method 239.1 

### or Method D3559-78A 

### or 

### B, or Method 301-A I1 

### or III, pp. 148-152, Atomic AbsorptionDirect Aspiration;

### or Method 239.2, Atomic AbsorptionFurnace Technique;



### or Method 

## * 200.7, Inductively Coupled Plasma Technique.

6. In 

### 5 141.24, which was published january 30,1991 (56

### FR 3526) and which 

### will become effectiveJuly 30,1992. paragraphs (e) and 

### (fl are revised paragraphs (h)(8),(h)(12) (iv), (vi), (r-Ti). and (h)(l3][i)are revised; and paragraph (h)[39) is added to read asset forth below. 

### In addition,paragraph (g), which

was not affected by the Jan. 30,1991 amendment, is amended by revising paragraph (g) introductorytext and adding [g)(8)to become effective July 30, 1992.


### 8 14’1.24 Organic chemicals other than total trihalomethanes, sampling and analyticall requirements.

e * * * *

(e)Analysis made to determine compliance with the maximum contaminant level for endrin in 

### 5 141.12(a) shall be made in accordance with EPA Methods 505, “Analysisof OrganohalidePestcides and Commercial Polychlorinated Biphenyl Products [Aroclors) in Water by Microextraction and Gas Chromatography”and 508. “Determination of Chlorinated Pesticides in Water by Gas ChromatographyWith an Electron Capture Detector.” The Methods are contained in “Methods for the Determination of Organic Compounds in Drinking Water,” 

### ORD Publications, CEEU, EPA/600/&88/039, December 1988. These methods are available from the National TechnicalInformation Service (NTIS),

### U.S.Department 

### of Commerce, 5285 Port Royal Road, Springfield,VA 22161. The toll-free number is 1-800-336-4700.



### (9 Beginning on January 1.1993, analysis of the contaminants listed in 

### 5 141.6l(a) (1) through (18)for the
purpose of determining compliance with the maximum contaminant level shall be conducted as follows:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distributionsystem which is representative of each well after
treatment [hereafter called a sampling point). Each sample must be taken at the

same samplingpoint unless conditions make another samplingpoint more representative 

### of each source, treatment plant, 

### or within the distributionsystem.

(21 Surface water systems 

### (or combined surface/ground) shal1 take a minimum of one sample at points in the distribution system that are representative of each source 

### or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same samplingpoint unless conditionsmake another samplingpoint

more representative of each source, treatment plant, 

### or within the distribution system.

(3) 

### If the system draws water from

more than one source and the sources

are combined before distribution,the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when
water representative of all sources is being used).

(4) Each community and non-transient non-community water system shall take four consecutivequarterly samples for each contaminant listed in 

### 5 141.61(a) (2) through (18) during each compliance period, beginning in the compliance period starting January 1,1993.

(5) 

### If the initial monitoringfor contaminants listed in 

### 5 141.61(a) (1) through (8) and the monitoring for the contaminants listed in 

### 5 141.61fa) (9) through (18)as allowed in paragraph (fl(l8)has been completed by December 31,1992, and the system did not detect
any contaminant listed in 

### 5 141.61(a) (1) through (la), then each ground and surface water system shalI take one sample annually beginning January 1. 1993.

(6) After a minimum of three years 

### of annual sampling,the State may allow groundwater systems with no previous detection 

### of any contaiminantlisted in $141.61(a)to take one sample during ea& complianceperiod.

(73Each community and non-transient groundwater system which does not detect a contaminant listed in 

### 8 141.61(a) (1) through (18) may apply to the State for a waiver from the requirements of paragraphs (f)(5) and (fl(6)

### of this section after completingthe initial monitoring. (Forthe purposes of this section, detection is defined as 

### 2 0.0005 

### mg/l.) A waiver shall be effective 

### for no more than six years (two complianceperiods).

(8) A State ma grant a waiver after evaluatingthe fo 

# T lowing factor(s): (i) Knowledge of previous use [includingtransport, storage, or disposal) of the contaminant within the watershed 

### or zqne of influence 

### of the system. If a determination by the State reveals no previous use of the contaminant within the watershed 

### or



# I3 zone of influence,a waiver may be granted.

(ii)If previous 

### use of the Contaminant 

### is unknown 

### or it has been used previously, then the followingfactors shall be used to determine whether 

### a waiver is granted.

(A)Previous analytical results. (B) The proximity of the system 

### to a potential point 

### or non-point source of contamination. Point sources include spills and leaks of chemicals at 

### or near a water treatment facility 

### or at manufacturing, distribution,

### or storage facilities,

### or from hazardous and municipalwaste landfills and other
waste handling or treatment facilities.

[C) The environmental persistence and transport 

### of the contaminants.



### (D] The number of persons sewed by the public water system and the proximity of a smaller system 

### to a larger system.

(E] 

### How well the water source 

### is protected against contamination. 

### such

as whether it is a surface 

### or groundwater system. Groundwater systems must consider factors such as depth 

### of the well, the type of soil, and wellhead protection. Surface water systems must consider watershed protection.

(9) As a condition of the waiver a groundwater system must take 

### one sample at each samplingpoint during the time the waiver is effective (Le., one sample during two complianceperiods



### or six years) and update its vulnerability
assessment consideringthe factors listed in paragraph (fl(8) of this section. Based on this vdnerability assessment the State must reconfirm that the system 

### is non-vulnerable.If the State does not make this reconfirmation within three
years 

### of the initial determination,then the waiver is invalidated and the system is required to sample annually as specifiedin paragraph 

## (51 of this section,

(10)Each community and nontransient surface water system which does not detect a contaminant listed in 

### 8 141.61[a) (1) through (18) may apply to the State for a waiver from the requirementsof (f)(5] 

### of this section after completing the initial monitoring. Systemsmeeting this criteria must be determinedby the State to be nonvulnerable based on avulnerability
assessment during each compliance period. Each system receiving a waiver shall sample at the frequency specified by the State 

### lif any).
(11)If a contaminantlisted in 

### 8 141.61(a] (2) 

### through (18) is detected at

a level exceeding 0.0005 

### mg/l in any sample,then:

# Yf 

### Federal Register 

## / Vot 66, 

### No. 126 

## 1 Monday, July 1, 1991 [ 

### Rules and 

### Regulations



### 8 141.C1[aj @)

### through [IS] 

### the laboratory 

### must:

[A)Analyze Performance Evaluation samples which include these substances provided by EPA Environmental Monitoring and SupportLaboratory 

### or equivalent samples provided by the State.

(B) Achieve the quantitative acceptance limits under paragraphs i[f)(l7(i)[C] and 

### [D) of this section for at 

### least 80percent of the regulated organic chemicalslisted in 

### 0 141.61[a] 

### (4 through (181.

[C] Achieve quantitative 

### results on the analyses performed under paragraph (flfl7)(i)(A] of this section that are within A20 percent of the actual amount of the substances in the Performance Evaluaiion sample when the actual
amount

### is greater than 

### or equal to 0.010 

### mgll.

(D) Achieve quantitative results on the analyses performed under paragraph (fj(l7)(i)(A) 

### of this section that are within t40percent of the actual amount of the substances in the Performance Evaluation sample when the actual
amount is less than 0.010 mg/l.

(E) Achieve a method detection limit of 0.0006 rngll, according

### to the procedures in appendix 

### B oEpart 138.

[ii).Toreceive certification 

### �orvinyl chloride, the laboratory 

### must:

(A) Analyze Performance Evaliiation samples providedby EPA EnvironmentalMonitoring and Support Laboratory 

### or equivalent samples providedby the State.



### [B) Achieve quantitative results on the analyses performedunder paragraph (f)(l7)[ii)(A) of this section that are within +40 percent of the actual amount of vinyl chloride in the Performance Evaluation sample.

(C) Achieve a method detection limit of 0.0005 

### mgll, according

### to the procedures in appendix 

### B of part 136.

(D) Obtain certification 

### for the contaminants listed in 

### 0 141.61(a) (2) through (18). (18)States may allow the use 

### of monitoring data collected after January 1,1988,required under section 1445 

### of the Act for purposes of initial monitoring compliance. If the data &re generally consistent with the other requirements in this section, the State may use these data (Le., a single sample rather than four quarterly samples) to satisfy the

i initial monitoring requirement

### of paragraph (f)(4)of this section. Systems which use grandfathered samples and did not detect any contaminant listed in 

### 0 141.61Ia) (1) through (181 shall begin monitoring annually in accordance with paragraph (f)(5) of this section beginning January 1,1993. (19) States may increase required monitoring where necessary to detect variations within the system. (201Each apprpved laboratory m~3t determinethe method detection limit 

### (WDL), as defined in appendix B to part 136,at which it is capable 

### of detecting VOCs. The acceptable 

### MDL is 0.0005 nag,& 

### This concentration isthe detection concentration for purposes 

### of this section. [21]Each publicwater system shall monitor at the time designatedby the State within each complianceperiod.

[g) 

### For systems in operation before January 1,1993,

### for purposes 

### ob initial monitoring, analysis of the contaminants listed in 

### 0 1;21.61(a](1) through (8)for
purposes of determiningcompliance with the maximum contaminant levels shall be conducted as follows:



### * * * * *

(8)Until January 1,1993,the State 

### may reduce the monitoring frequencyin paragraphs 

### (glil] and (g)[Z) of this section, as explained in this paragraph.

* * * * *



### (h] * * 

### * [8] Systemswhich violate the requirements of 

### 8 141.61(c)as determinedby paragraph (h)(ll) of this section must monitor quarterly. After a minimum of four quarterly samples show the system is in complianceand the State determines the systemis reliably and consistently below,the 

### MCL, as specified in paragraph (h)(ll)

### of this section, the system shall monitor at the frequency specified in paragraph [h][i’J[Mii) of this section,

* e * * *

(121 * 

# ­ [iv) Method 508, “Determination

### of ChlorinatedPesticides in Water by Gas Chromatographywith an Electron Capture Detector.” Method 508 can be used to measwe chlordane,heptachlor. heptachlor epoxide,lindane, methoxychlorand toxaphene. Method 508 can be used as 

### a screen for 

### PCBs.



### * * * * *

(vi) Method 515.1, Revision 5.0, “Determinationof ChlorinatedAcids in Water by Gas Chromatographywith an Electron Capture Detector”asrevised May 1991. Method 515.1 can be used to

measure 2,4-D, 2A5-W (Silvex) and pentachlorophenol.

(vii] Method 525.1, Revision 3.0 ‘’Determination

### of OrganicCompounds in DrinkingWater by Liquid-Solid Extraction and Capillary Column Gas Chromatography /Mass Spectrometry”

asrevised May 1991.Method 525.1 can 

### be used to measure alachlor, atrazine, chlordane,heptachlor, heptachlor epoxide,lindane, methoxychlor, and pentachlorophenol.



# E5 Contaminant Acceptance limits (percent)

DECP



## ......

## ............................ It 40. EDB



## ...................................... f 40. Alachlor



## ............................... f 45. Atrazine



## ............................... f 45. Cmbfuran



## .......................... f 45. Chlordane



## ............................ f 45. Heptachlor



## .................

~ 

## ........ f 45. Heptachlor Epoxide



## ........... f 45. Lindane



## ................................ If 45. Methoxyctdor



## ...................... -+ 45. PCBS (as

Decachlorobiphenyl). 0-200. Toxaphene



## ......................... f 45. Aldicarb



## ............................... 2 standard d8uiationh. Aldicarb sulfoxide



## ............... 2 standard Uevialitml Aldjcarb sulfone



## .................. 2 standard deviations. Pentachbrophenol



## ............. 50. 2,4-0



## .................................... 

# * 50. 2.4-TP



## .................................. -C 50.

(ii) [Reserved] 7. 

### IA 

### 8 141.32. paragraphs (e)ll6), (25) through (27), and (46) are added to reed



### as follows:

141.33 Public notification,



### * * * * *

(e] 

### * (16)

### Burium. The United States Environmental.Protection Agency 

### (BPAJ
sets 

### drinking water standards 

### @adhas determined

### that barium is

### a health iconcern at certain levels 

### of exposureb 

### rhis inorganicchemicaloccursnafutklly in some aquifers 

### that serve as sources 

### of ground water. It 

### is also used 

### h oil and
gas drilling muds, automotivepaints, bricks, tiles andjet fuels. It generally gets into drinkingwater after didsdving from naturally occurringminetala

### in 

### the ground. This chemicalmay danigge the heart and cardiovascular system, and is associated with high blood pressure 

### in laboratory animals such as

### rats exposedto high levels duriq their lifetimes. 

### In humam,

### W A h h &et 

### e�f& 

### hm barium 

### on 

### bkd pmsswze:

### should R&

occur 

### kl~w 

### aprs pea mi&m 

### [pp] 

### in drinking water. W A

### has set the drinking
water standard 

### for barium at 2 parts per million kppm] to 

### p~tect against the 

### risk of these adverse health effects, 

### Drinking
water that meets theEPA standard is assaciated with 

### little t~acme 

### of 

### thin

### risk and is considered safe with 

### respect ta barium,

* * * * e

(25)Al&&. 

### The ExRieed Stah
h\nfFQrrmf?Ilkdhd&hA@?aCy 

### @PA)
seta 

### d&king waba stmdards 

### a d has determined 

### that 

### al&cmh b a

### hedth

concern at

### mtah

### levels Q�

### expure* Aldicdk a 

### wic$elyas& pstici$e: Under certain soil and climatic conditions (e.&+ mdy

### mil and.

### hi& raidall), 

### aldimbmay 

### Lsb into~FQW~ water after normal agrkdtmrzlb applications to crops such aspotatoes 

### or peanuts or 

### may enter drinking water supplies as a result of 

### surfam remoff. nis

### chmiml h&S 

### ken shm trr damage the nervous system in laboratory animal 

### SA a8rats 

### and dogs exposed to high 

### levels. 

### EPA has set the drinking wztter standard 

### for al&&
at 0.003 parts 

### per million fspml ta protect against &e 

### risk af adverse health effects. 

### Drinking w&er that 

### meets the EPA standad is associated with little to none of this 

### risk and 

### is considered 

### safewith respect tu aMmb.

(26) 

### Aldiccarbt~uI$oxide. 

### TheUrnit& States Kvircmmentak 

### PratectianAgency (EPAJ

### sets &inking water staa&mb 

### ad has determined 

### that aldicadii&&de is B health conm&at mtak 

### levelsof exposure.Aldicarb is a widely used pesticide. AIdicarb suIfoxEde

### in ground
water is primarily a breekdwwn pdact of 

### aildicarb..Under 

### certabmil at& ckimaticeonditiam 

### [@.e.. sandy 

### so& 

### and high rainfall], aldicarb sulfoxidg

## mar leach into gsomd water after noma1 agricultural appEimHms tacmps web

as potatoes or peanuts 

### or may enter drinking water supplies as a pedr

### d surface 

### wff. This &emid

### has 

### heen Shorn aQ thTIZL@ WCEBS 

### Qm h lahat- 

### hala sa& as rats and dogs 

### exgoredte~ 

### high 

### h& EPA h a E& the 

### &inkkgwater 

### standardjar a&& SpllliO~ate atWm4 pa* perxdhiorr [p]
tap~&& against the&Jc 

### ofadverse health effeds. h);IinkjSllg,

### mtm hlBnEetS the EPA stmd;llb is 

### twmcha 116th little tamme 

### d 

### ahis risk &is l33msidd 

### safe withmg- 

# * &&c& 

### sulf&&

(n)iL&J&yrb~-atERitecil States Envmmm e;ntalprOWs~ 

### (EPA)s&Bs drimhg water tatadda

### aad has Clarter- tibt alakmb

### mHme is Contaminant WLa 

## w

la Section adding to the fc)(3),(c][4Jv and 

### (c)@@ to 

### maad as 

### fahs:



### 0 141.M brimw

### c-kuekorganic contmhan&



### * * * * *

*

CAS hloi cwi+amicaarb 

# (Z

* c t * I (2) 1 ?&OW?



## .............. Aldlcerb.

## .....-.........

## -... 0.0110 (3) 1-74



## ........... sylloxicl$-- @$md t* wIt?M%?-4 

## --..".* 

### ..-- am

6 * 6 I 

# . (16) 87-86-5



## .............. PentaMnmphd 

## .-. Qool

(1) Fluoride



## .................................................. 4.0 *

c * 

# ­

(3) WiiJRt



## ..................................................... 2

t 

# . t 0 *

* * * * *

### Federal Register 

## / Vol. 56, 

### No. 126 

## / Monday, July 

### 1, 1991 

## / Rules and 

### Regulations 

### 90281

PART 142-NATIONAL PRIMARY DRINKINGWATER REGULATION§ IMPLEMENTATION

12. The authority citation for part 142 continues to read asfollows:

Authority: 42 U.S.C. 3*, 3OOg-l.3OOg-2, 300g-3,300g-4,300g-5,300g-e. 3mj4 and 300j-9.

13. In 

### 0 142.57, which was published January 30,1991 (56

### FR 3526) and will become effective July 30,199~, paragraph (b)isrevised to read as 

### foIlows:



### 0 142.57 BottledWater, Point-of-Use.

e * * * *

(b) Public water systems using bottled
water as a condition of obtaining an exemption from the requirements 

### of 

### 88 141.61 (a] and (c) and 

### 0 141.62’(b] must meet the requirements in 

### 8 112.62(g).



### * * * * *

PART 143-NATIONAL SECONDARY DRINKINGWATER REGULATtONS

14, The authority citation 

### forpart M3 continues to read as follows:

Authoriw42 

### U.S.C.3oog-1(e),3ooj-4 and 

### 3ooi-9.

15. 

### In 0 f43.4, which was

### publ-i-shed January 3 a 1991 (58

### FR 3526) and

### which will become eE&ve Xuly 30,1992 paragraphs [b] (121and (13)are revised
to read asfollows:

$143.4 Monitoring.

* * * * *



### (h) * 

### * *
(12)Aluminum-Method 202.1 Atomic Absorption Technique-Direct Aspiration: 

### or Method 2 3064 

### or Method 9 I-305i-85, 

### or Method 1 202.2 Atomic Absorption-Graphite Furnace Technique; 

### or Method 304; 

### or Method 4

“Methodsof ChemicalAnalysis of Water end Wastes.” EPA, EnvimnmentalMonitoring and Systems Laboratory,Cincinnati, OH 45268, EPA 600/4-79420, March. 1983. Available fmm ORD Publication,CERI,EPA, Cincinnati, OH 45268

2 ”Standard Methods for the Examinationof Waler and Wastewater.” 16th Ed., American Public Health Association.American Waterworks Association,Water Pollution ControlFederation, 1985. “Methodsfor the Determinationufhrganic Substancesin Water and Fluviai Sediments,” Techniques of Water-Resources Investigationsof the United States Geological SurveyBooks, Chapter Al. 1985.Available !?om Opee File Services Section,Western DistributionBranch, U.S Geological Survey, DenverFederal Center, Denver, 

### co 80255. *%?termination of Metals andTraceElements .by

EnductivelyCoupled Piasma-AtomicEaission Spectrometry,”Method 200.7, version 3.2.Awst 1990, EF’A hvironmental Monitoringend Systems Labopatory, CincinRati. OH 200.7 Inductively-Coupled Plasma Technique: 

### or Method 200.8 Inductively Coupled Plasma-Mass Spectrometry 

### or Method 200.9 Platform Technique: 

### or Method 3120B Inductively-Coupled Plasma Technique.
(131 Silver-Method 272.1 Atomic Absorption Technique-Direct Aspiration; or Method 2 324A; 

### or Method 9 1-3720-85;

### or Method 2722 Atomic Absorption-Graphite Furnace Technique: 

### or Method 304;

### or Method
200.7 Inductively-Coupled PlasmaTechnique; or Method 6 200.8 Inductively-Coupled Plasma-Mass Spectrometry; 

### or Method 200.9 Platform Technique: 

### or Method 312OB Inductively-Coupled Plasma-Technique. [FR Doc. 91-15564 Filed 6-28-91;8&5 arnl

BILLtNO CODE 6580-504

6 “Determinationof and Trace Elements in Water ant! Wastesby InductivelyCouple13Plesma-dJlrrSs Spectrometry.”Method 200.8, version 4.3, &qp&, 1990,EPA. EnvironmentalModioringaad Sgetenrii Laboratory,Cincinnati, OH 4526&&&&iie fpanr ORD Publication,CERI, EPA. Cincinn&.WR&Z@3.

6 “Determinationof Metals and Trace Elements by Stabilized Temperature Graphite &mace Atomic Absorption Spectrometry,” Me&a&do0.3, version 1.1, August, 1990. @A, Envirenmentd Monitoring and SystemsLaboratory+Cincima%i.OH 45268.

7 “Standard Methods for the ExaRllnatien ol Water and Wastewater,” 16the&, Anxerican%krk Health Association,American W e d Association,Water Pollution canhofEedwatim,
1985.