94-29692. National Primary and Secondary Drinking Water Regulations: Analytical Methods for Regulated Drinking Water Contaminants.  

  • [Federal Register Volume 59, Number 232 (Monday, December 5, 1994)]
    [Unknown Section]
    [Page 0]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 94-29692]
    
    
    [[Page Unknown]]
    
    [Federal Register: December 5, 1994]
    
    
         
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    Part II
    
    
    
    
    
    Environmental Protection Agency
    
    
    
    
    
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    40 CFR Parts 141 and 143
    
    
    
    Analytical Methods for Regulated Drinking Water Contaminants; Final 
    Rule
    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Parts 141 and 143
    
    [WH-FRL-5116-4]
    RIN 2040-AC12
    
     
    
    National Primary and Secondary Drinking Water Regulations: 
    Analytical Methods for Regulated Drinking Water Contaminants.
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Final rule.
    
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    SUMMARY: EPA is promulgating the use of several new analytical methods 
    and updated versions of previously approved methods for a number of 
    regulated contaminants in drinking water. At the same time, the Agency 
    is withdrawing approval of outdated methods or outdated versions of the 
    same methods. The purpose of the rule is to approve new methods, 
    withdraw outdated methods, and update older methods for analysis of 
    regulated contaminants in drinking water. The rule is expected to 
    eliminate unnecessary duplication by withdrawing older versions of the 
    same method, and satisfy public requests for approval of new 
    technologies in drinking water analyses.
    
    DATES: This final rule is effective on January 4, 1995. The 
    incorporation of the publications listed in this document are approved 
    by the Director of the Federal Register as of January 4, 1995.
    
    ADDRESSES: Copies of the public comments received on the proposal, 
    EPA's responses, and all other supporting documents are available for 
    review at the U.S. Environmental Protection Agency (EPA), Drinking 
    Water Docket, 401 M Street, S.W., Washington, D.C. 20460. For access to 
    the docket material, call (202) 260-3027 on Monday through Friday, 
    excluding Federal holidays, between 9:00 am and 3:30 pm Eastern Time 
    for an appointment.
    
    FOR FURTHER INFORMATION CONTACT: Dr. Jitendra Saxena, Drinking Water 
    Standards Division, Office of Ground Water and Drinking Water (4603), 
    U.S. Environmental Protection Agency, 401 M Street, S.W., Washington, 
    D.C. 20460, (202) 260-9579. General information may also be obtained 
    from the EPA Safe Drinking Water Hotline. Callers within the United 
    States may reach the Hotline at (800) 426-4791. The Hotline is open 
    Monday through Friday, excluding Federal holidays, from 9:00 am to 5:30 
    pm Eastern Time.
        For technical information regarding chemistry methods, contact 
    Richard Reding, Ph.D., Office of Ground Water and Drinking Water (TSD), 
    U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, telephone 
    (513) 569-7946, or Baldev Bathija, Ph.D., Office of Ground Water and 
    Drinking Water (MC-4603), U.S. Environmental Protection Agency, 
    Washington, D.C. 20460, telephone (202) 260-3040. For technical 
    questions regarding microbiology methods, contact Paul S. Berger, 
    Ph.D., Office of Ground Water and Drinking Water (MC-4603), U.S. 
    Environmental Protection Agency, Washington, D.C. 20460, telephone, 
    (202) 260-3039.
    
    SUPPLEMENTARY INFORMATION:
    
        EPA Regional Offices:
    
    I JFK Federal Bldg., One Congress Street, 11th floor, Boston, MA 
    02203, Phone: (617)565-3610, Jerry Healey
    II 26 Federal Plaza, Room 824, New York, NY 10278, Phone: (212) 264-
    1800, Walter Andrews
    III 841 Chestnut Building, Philadelphia, PA 19107, Phone: (215) 597-
    9873, Stuart Kerzner
    IV 345 Courtland Street, N.E., Atlanta, GA 30365, Phone: (404) 347-
    3633, Wayne Aronson
    V 77 West Jackson Boulevard, Chicago, IL 60604, Phone: (312) 353-
    2151, Ed Watters
    VI 1445 Ross Avenue, Dallas, TX 75202, Phone: (214) 655-7150, Thomas 
    Love
    VII 726 Minnesota Avenue,Kansas City, KS 66101,Phone: (913) 276-
    7032, Ralph Langemeir
    VIII One Denver Place, 999 18th Street, Suite 500, Denver, CO 80202-
    2466, Phone: (303) 293-1652, Patrick Crotty
    IX 75 Hawthorne Street, San Francisco, CA 94105, Phone: (415) 744-
    1817, William Thurston
    X 1200 Sixth Avenue, Seattle, WA 98101, Phone: (206) 553-4092, 
    Kenneth Feigner
    
    Table of Contents
    
    I. Statutory Authority
    II. Regulatory Background
    III. Explanation of Today's Action
    IV. Response to Comments Received on the Proposed Rule and Notice of 
    Availability
    V. Availability and Sources for Methods Information
    VI. Regulation Assessment Requirements
    VII. References
    
    I. Statutory Authority
    
        The Safe Drinking Water Act (SDWA), as amended in 1986, requires 
    EPA to promulgate national primary drinking water regulations (NPDWRs) 
    which specify maximum contaminant levels (MCLs) or treatment techniques 
    for drinking water contaminants (42 U.S.C. 300g-1). NPDWRs apply to 
    public water systems (42 U.S.C. 300f(1)(A)). According to section 
    1401(1)(D) of the Act, NPDWRs include ``criteria and procedures to 
    assure a supply of drinking water which dependably complies with such 
    maximum contaminant levels; including quality control and testing 
    procedures. * * *'' In addition, Section 1445(a) of the Act authorizes 
    the Administrator to establish regulations for monitoring to assist in 
    determining whether persons are acting in compliance with the 
    requirements of the SDWA. EPA's promulgation of analytical methods is 
    authorized under these sections of the SDWA as well as the general 
    rulemaking authority in SDWA Section 1450(a) (42 U.S.C. 300j-9(a)).
    
    II. Regulatory Background
    
        EPA has promulgated analytical methods for all currently regulated 
    drinking water contaminants for which MCLs or monitoring requirements 
    have been promulgated. In most cases, the Agency has promulgated 
    regulations specifying (i.e., approving) use of more than one 
    analytical method for a contaminant, and laboratories may use any one 
    of them for determining compliance with an MCL or monitoring 
    requirement. After any regulation is published, EPA may amend the 
    regulations to approve additional methods, or modifications to approved 
    methods, or withdraw methods that become obsolete.
        On December 15, 1993, EPA proposed to approve the use of several 
    new methods and modifications of existing methods that EPA believed 
    were as good as, or better than, current methods and procedures (58 FR 
    65622). The Agency also proposed to withdraw approval for outdated 
    methods or outdated versions of the same methods. In addition, EPA 
    published a Notice of Availability (NOA) (59 FR 35891) on July 14, 
    1994, to make available data from EPA's evaluation of several new 
    analytical methods, and to propose withdrawal of approval for several 
    outdated EPA methods. EPA requested public comments on the proposal and 
    on the NOA. Today's notice takes final action on the methods covered by 
    the proposal and the NOA.
    
    III. Explanation of Today's Action
    
        With a few minor exceptions, which are described below, the actions 
    described in the 1993 proposed rule and the 1994 NOA are approved in 
    today's rule. The coliform transit time will remain at 30 hours, and 
    the Agency will not require systems to hold samples at 10  deg.C during 
    transit. EPA will approve the Colisure test for simultaneously 
    determining the presence of total coliforms and E. coli.
        In the July 1994 NOA, EPA described the new versions of EPA Methods 
    200.7, 200.8, 200.9, 245.1 (EPA, 1994a) and 504.1 (EPA, 1993d) that are 
    approved in today's rule. Mercury and sodium have been added to the 
    analytical scope of Methods 200.8 and 200.7, respectively. EPA is 
    approving EPA Method 508.1 (EPA, 1994c), which allows liquid-solid 
    extraction (LSE) procedures to be used under Method 508 conditions for 
    analysis of many analytes contained in EPA Methods 507 and 508. A minor 
    revision to dioxin method 1613 that allows use of LSE is approved. 
    Hexachlorocyclo-pentadiene has been added to the analytical scope of 
    EPA Method 508.
        Trimethylsilyldiazomethane may be used as an alternative 
    derivatizing reagent in Methods 515.1 and 515.2. EPA Methods 150.1, 
    150.2 and 515.1 are not withdrawn. Turbidity measurements of samples 
    need not be made immediately before beginning an analysis for metals; 
    it is only necessary that the sample be acidified and held for sixteen 
    hours. For EPA Method 531.1 (carbamates), samples no longer need to be 
    frozen, thereby eliminating the possibility of frozen samples breaking 
    the sample vial. Standard Method 6610 is approved as an alternative to 
    Method 531.1. Analysis for 2,3,7,8-TCDD (dioxin) with Method 1613, or 
    for asbestos with Method 100.1 or 100.2 can be simplified by using the 
    guidance contained in the EPA document, Technical Notes on Drinking 
    Water Methods (EPA, 1994d).
        Technical Notes contains mandatory and optional procedures that 
    will be cited in the drinking water regulations.
        EPA is also correcting minor errors in the 1993 proposal. An 
    erroneous listing of USGS methods I-2822-85 and I-2823-85 for sulfate, 
    and ASTM D2036-91A for cyanide are removed in today's rule. The ASTM 
    method had been listed twice in the table of approved methods. A 
    typographical error occurred in listing the USGS method for silver and 
    the ASTM method for chloride. The correct listings are USGS I-3720-85 
    (silver) and ASTM D4327-91 (chloride).
        The effective date for all actions in this rule, except withdrawal 
    of obsolete methods, is January 4, 1995. The withdrawal date for 
    obsolete methods is July 1, 1996 (or 18 months from publication, 
    whichever is later), which is a year later than proposed. After this 
    date, EPA's manual ``Methods for Chemical Analysis of Water and 
    Wastes'' (EPA, 1983a) will contain only three approved drinking water 
    methods--Methods 150.1, 150.2, and 245.2. To spare new laboratories the 
    expense of purchasing this manual, EPA will provide single copies of 
    these methods to users who do not have a copy of the 1983 manual. For 
    the convenience of readers and for clarity of the rules, methods that 
    are withdrawn will be specified only by tabulating them in the 
    document, Technical Notes on Drinking Water Methods (EPA, 1994d), and 
    in the next revision of the Manual for the Certification of 
    Laboratories Analyzing Drinking Water (EPA, 1990b).
    
    IV. Response to Comments Received on the Proposed Rule and Notice 
    of Availability
    
        EPA received 136 comments on the December 15, 1993, proposal; 92 
    comments were related to chemical-analytical methods and 79 comments 
    were related to the methods associated with the coliform and surface 
    water treatment rules. The Agency received twenty comments on the July 
    14, 1994, Notice of Availability. The commenters included analytical 
    laboratories, water utilities, analytical instrument manufacturers, 
    State and local regulators, and trade associations.
        A summary of major comments and the Agency's response to the issues 
    raised are presented in this section. The Agency's detailed response to 
    the comments received on the 1993 proposed rule and the 1994 NOA is 
    available in the public docket for this rule (EPA, 1994e).
    
    A. New Methods
    
        Comment on the ten new methods was favorable. These methods, EPA 
    methods 100.2, 551, 552.1, 555, Standard Methods 4500-Cl-E, 4500-Cl-H, 
    4500-Cl-I, 4500-O3-B, 4500-ClO2-E and Great Lakes Instruments 
    Method 2 were described in the 1993 proposal. Specific public comments 
    on some of the methods are answered below.
        EPA Method 100.2 (asbestos)  Four comments contained several 
    suggestions and criticisms. Method 100.2 has been editorially revised 
    to reflect the comments. These changes, however, do not affect the 
    performance, cost or applicability of the method. One commenter asked 
    EPA to approve SM 2570 for asbestos, which was published in a 1994 
    supplement to the eighteenth edition of Standard Methods (APHA, 1994). 
    EPA does not approve SM 2570 for asbestos in today's rule, because this 
    method differs in significant ways from Method 100.2. For example, SM 
    2570 uses a larger pore filter (0.45 micron) to trap asbestos fibers, 
    while EPA method 100.2 uses a 0.22 micron filter. The commenter did not 
    provide any data comparing asbestos trapping efficiency of these two 
    filters, whereas EPA has data (EPA, 1994e) to show that larger pore-
    size filters trap fewer asbestos fibers in drinking water samples.
        Method 552.1  A commenter asked that the sodium hydroxide rinse in 
    Method 552.1 be optional, because the rinse is not compatible with 
    their LSE product. Method 552.1 was developed and validated with ion 
    exchange cartridges to take advantage of the special chemical 
    properties of dalapon and the other acids covered by the method. To 
    efficiently extract the acids the ion exchange resin must be activated 
    with a sodium hydroxide rinse. Sorbent conditioning and elution steps, 
    which are specified in Method 552.1 or any LSE method, cannot be 
    modified or eliminated to accommodate the support material. Thus, EPA 
    will not allow the sodium hydroxide rinse in Method 552.1 to be 
    optional, because EPA has received no data to support the commenter's 
    request to make the rinse optional.
        The same commenter asked for a more generic definition of LSE media 
    in Method 552.1 and in other LSE methods. The commenter believes EPA is 
    unnecessarily narrowing the choice of LSE disks and cartridges. EPA 
    does not believe LSE methods are overly restrictive in allowing use of 
    alternative LSE disks or cartridges. However, EPA believes that 
    additional guidance to help users correctly choose alternative LSE 
    media without compromising the reliability of the analysis would be 
    useful. The guidance is summarized below and will be published in 
    Technical Notes on Drinking Water Methods (EPA, 1994d). The guidance is 
    applicable to all LSE methods and supersedes the phrase ``or 
    equivalent'' that is used in some methods to describe selection of 
    alternative LSE cartridges or disks.
        Liquid-solid extraction is performed using various sorbents that 
    are either packed into a cartridge or enmeshed in a disk of inert 
    support material. EPA methods describe the cartridge or disk that was 
    used to develop the LSE procedure, and to produce the data which is 
    published in the method. If a product is mentioned in the methods, it 
    is for information purposes only. EPA believes various LSE cartridges 
    and disks may be used, provided they meet all quality control 
    requirements of the method, and provided they contain a sorbent that 
    uses the same physicochemical principles as the cartridge or disk that 
    is described in the approved LSE method. To demonstrate that 
    alternative LSE cartridges and disks meet all quality control criteria, 
    the analyst must be aware of the chemistry of the method. For example, 
    in evaluating Method 552.1 the recovery of the free acid (not a 
    chemical derivative) from the water sample must be tested with the 
    alternative LSE cartridge or disk.
        In judging LSE disk media, both the sorbent and the support must be 
    evaluated. In the case of sorbents, similarities in polarity are not 
    sufficient. For example, a C18-Silica sorbent may not perform the 
    same as a styrene divinylbenzene copolymer sorbent. Thus, these 
    sorbents would not be considered to be equivalent. In judging supports, 
    any physical support used to hold the sorbent is acceptable provided 
    the support is inert and compatible with the solutions or solvents 
    required in the conditioning and elution steps of the method. However, 
    any sorbent conditioning or elution steps, which are specified in the 
    method must not be modified or eliminated to accommodate the support 
    material.
        EPA Method 555  Several commenters noted that the method detection 
    limits (MDLs) for some analytes were greater than MDLs in the 
    alternative method (EPA Method 515.1), or were too high to meet 
    monitoring triggers, which are specified at 40 CFR 141.24(h)(18). Thus, 
    they questioned whether Method 555 was a suitable alternative to Method 
    515.2. EPA believes commenters mistakenly looked at MDLs in Table 2 of 
    Method 555, which shows the results of spikes at 10 ppb. However, 
    spikes at 0.5 ppb (Table 5 in the method) resulted in MDLs that are 
    equivalent to Method 515.1 MDLs, and these MDLs have been validated in 
    a second laboratory (EPA, 1992a). EPA also notes that monitoring 
    triggers for several organic contaminants, including Method 555 
    analytes, may be amended in a future rulemaking (EPA, 1993b, 1994f).
        Great Lakes Instruments (GLI) Method 2 (turbidity)  Some commenters 
    objected to the method because it is vendor and instrument-specific. 
    EPA generally develops and approves methods that are not vendor-
    specific. Users are not limited to the GLI method; generic methods SM 
    2130B and EPA 180.1 are approved for turbidity. However, under the 
    Alternative Test Procedures (ATP) program EPA has approved vendor-
    specific methods or products as alternatives to approved methods (53 FR 
    5142, February 19, 1988). GLI Method 2 was evaluated under EPA's ATP 
    program and recommended for approval as an alternative method. EPA 
    realizes GLI is the source of copies of GLI Method 2, which is a factor 
    a laboratory choosing to adopt this method must consider.
        Some commenters believed the GLI method should be approved as a 
    version of an international procedure, ISO 7027. The ISO procedure 
    measures turbidity via either 90 deg. scattered or transmitted light 
    depending on concentration. Although instruments conforming to ISO 7027 
    specifications are similar to the GLI instrument, only the GLI 
    instrument uses pulsed, multiple detectors to simultaneously read both 
    90 deg. scattered and transmitted light. EPA has received no data on 
    the ISO 7027 use of separate 90 deg. scattered or transmitted light 
    measurements to judge equivalency to other approved turbidity methods.
        SM 4500-Cl-E, Low Level Amperometric Titration  A commenter noted a 
    typographical error in a calculation in SM 4500-Cl-E, which the 
    Standard Methods Committee has agreed to correct. In approving SM 4500-
    Cl-E, EPA will print the correct formula for SM 4500-Cl-E in Technical 
    Notes on Drinking Water Methods (EPA, 1994d). The Standard Methods 
    Committee will publish a correction to this method in the next (19th) 
    edition of Standard Methods (Eaton, 1993a).
        SM 6610 (APHA, 1994)  A commenter asked to approve this method as 
    an alternative to EPA Method 531.1. EPA aided the development of this 
    method, which was published in 1994 in a supplement to the eighteenth 
    edition of Standard Methods. EPA agrees with the commenter, and will 
    approve SM6610 for analysis of aldicarb, aldicarb sulfone, aldicarb 
    sulfoxide, carbaryl, carbofuran, 3-hydroxycarbofuran, methomyl, and 
    oxamyl.
        EPA Method 1613, Revision B, dioxin (EPA, 1994i)  EPA was asked to 
    replace the approved Revision A of Method 1613 with Revision B. EPA 
    agrees with the suggestion. As with Revision A, users can greatly 
    simplify use of Revision B of Method 1613 when only 2,3,7,8-
    tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is to be determined in 
    drinking water samples by using procedures described in Technical Notes 
    on Drinking Water Methods (EPA, 1994d).
        EPA proposed Revision A of Method 1613 for the monitoring of 
    several chlorinated dioxins and furans under the Clean Water Act on 
    February 7, 1991 (56 FR 5090), and approved it only for measurement of 
    2,3,7,8-TCDD under the Safe Drinking Water Act on July 17, 1992 (57 FR 
    31803). In response to comments on the 1991 proposal, EPA developed 
    Revision B. The only technical changes made in Revision B that affect 
    determination of 2,3,7,8-TCDD in drinking water matrices are (1) slight 
    changes in performance specifications based on the compilation of data 
    from interlaboratory and other studies, (2) additional language 
    intended to provide analysts with increased flexibility to use liquid 
    solid extraction procedures, and (3) further clarification of the 
    documentation required when analysts employ the flexibility provided in 
    the method to use alternate techniques not explicitly described in the 
    method.
    
    B. Expanded Scope for Already Approved Methods
    
        Comments on expanding the analytical scope of these five methods 
    were favorable. These methods, EPA Methods 200.8, 200.9, 300.0, SM 
    4110B, and American Society for Testing and Materials (ASTM) method 
    D4327-91, were discussed in the 1993 proposal or the 1994 NOA. Specific 
    comments requesting that approved methods cover additional analytes are 
    described and answered below.
        A commenter asked EPA to expand the scope of Method 200.8 to 
    include additional metals that are not currently regulated by EPA. 
    While EPA encourages laboratories to use any approved method for all 
    contaminants that are within the analytical scope of the method, EPA 
    can only approve a method for contaminants that are regulated. One 
    commenter asked why Method 200.9 did not include the secondary drinking 
    water contaminant, zinc. EPA believes analysis of zinc with Method 
    200.9 is impractical, because the instrument and procedure used are 
    very sensitive to small amounts of lead. The analysis is subject to 
    random contamination, and the concentration range of zinc that can be 
    reliably measured is too narrow to be of use with typical drinking 
    water samples. EPA recommends more suitable methods (EPA 200.7, 200.9, 
    SM 3120B and SM 3111B) for measurement of zinc in drinking water 
    samples.
        Commenters were concerned about expanding the scope of the ion 
    chromatography methods to include fluoride. They believed that EPA did 
    not have data to show that interference problems would not preclude use 
    of ion chromatography for the analysis of fluoride in drinking water 
    samples. EPA's 1990 study (Bionetics) which involved participation of 
    seventeen laboratories demonstrated that fluoride can be reliably 
    measured in drinking water samples with ion chromatography. Thus, EPA 
    has no hesitation in approving the three proposed ion chromatography 
    methods for the analysis of fluoride in drinking water.
    
    C. Updated Methods
    
        Comment on updating earlier versions of six methods to the current 
    versions was favorable. These methods, EPA Methods 504.1, 515.2, 524.2, 
    525.2, 548.1 and 549.1, were discussed in the 1993 proposal or the 1994 
    NOA. Problems were reported by a commenter with the use of 
    trimethylsilyldiazomethane (TMSD) for derivatization of the analytes in 
    Methods 515.1 and 515.2. The commenter suggested that EPA also allow 
    the use of diazomethane for this purpose. EPA agrees with the commenter 
    and, as discussed in the 1993 proposal, EPA allows use of either 
    derivatizing reagent. However, because dalapon is not adequately 
    derivatized by TMSD, the use of TMSD in Method 515.1 is not approved 
    for analysis of dalapon. Procedures for using TMSD with Methods 515.1 
    and 515.2 are described in the document Technical Notes on Drinking 
    Water Methods (EPA, 1994d).
    
    D. Updates to Methods by Reference to Most Recent Manual
    
        Comments were favorable on approving versions of previously 
    approved methods that are now contained in the eighteenth edition of 
    Standard Methods (APHA, 1992) and in five new EPA manuals (EPA, 1994a, 
    1991, 1990a, 1992b and 1993a). These publications were described and 
    discussed in the 1993 proposal or the 1994 NOA. Questions or requests 
    from commenters about some of the methods contained in these 
    publications are described and answered below.
        1994 EPA Metals Manual (EPA, 1994a)  Three commenters asked to add 
    other regulated metals to the scope of Method 200.7, because use of a 
    new axial configured inductively coupled plasma (ICP) atomic emission 
    spectroscopy (AES) instrument improves the sensitivity of the method to 
    the required regulatory limits. EPA will not approve this request in 
    today's rule, because Method 200.7 as written allows use of other types 
    of ICP/AES instruments that cannot meet the regulatory limits for the 
    additional metals. To extend the scope of Method 200.7 as suggested by 
    the commenters would require either a formal ATP approval (EPA, 1993c), 
    or publication of a new AES method that allowed only instruments with 
    an axial configuration.
        1991 Organic Methods Manual (EPA, 1991)  One commenter requested a 
    change in the scope of EPA Method 505 because of the detection limits 
    for some method analytes. These changes included withdrawal of 
    alachlor, atrazine and simazine, and addition of toxaphene. EPA is 
    evaluating the detection limits in several methods. When this 
    evaluation is complete, EPA may propose to withdraw approval of methods 
    or modify the scope of methods, such as Method 505. In the interim, EPA 
    does not agree that the scope of Method 505 should be changed to 
    withdraw alachlor, atrazine and simazine. However, EPA agrees that 
    analysis for these nitrogen-containing compounds may require use of a 
    nitrogen-phosphorous detector (NPD) rather than the electron capture 
    detector (ECD). Today's rule specifies that an NPD should be 
    substituted for the ECD in Method 505 (or another approved method 
    should be used) to determine alachlor, atrazine and simazine, if lower 
    detection limits are required.
        EPA agrees with the comment about toxaphene. In today's rule EPA is 
    correcting an omission in the 1993 proposal by continuing to approve 
    Method 505 for toxaphene. However, EPA notes that the Method 505 MDL 
    for toxaphene is very close to the MCL. To improve the sensitivity of 
    the analysis analysts may wish to use Method 508 for toxaphene and 
    other Method 505 analytes for which use of an NPD will not improve the 
    sensitivity. Method 508 is very similar to Method 505 except that the 
    MDLs are lower, because a larger sample volume is extracted.
        MCL compliance determination for PCBs requires that EPA method 505 
    or 508 be used as a screen for PCBs as Aroclors prior to quantitation 
    as decachlorobiphenyl by EPA Method 508A. Three commenters requested 
    that EPA switch the sequence of compliance methods for PCBs, i.e., use 
    Method 508A to screen and Method 505 or 508 to quantify PCBs. The 
    suggested change in the sequence of compliance methods is beyond the 
    scope of this rule since it would require amending the MCL compliance 
    determination sequence in 40 CFR 141.24(h)(13)(i)-(iii). Only Method 
    508A can measure decachlorobiphenyl, and Sec. 141.24(h)(13)(ii) 
    specifically requires ``using Method 508A to quantify PCBs as 
    decachlorobiphenyl''.
        It was suggested by a commenter that EPA include hexachloro- 
    cyclopentadiene (HCP) in the scope of EPA Method 508. EPA agrees with 
    the commenter, and will allow measurement of HCP with EPA Method 508. 
    However, the analyst must show that the analyte recoveries and other 
    criteria, which are specified for HCP in Section 9 of Method 508.1 are 
    achieved using Method 508 procedures. This option will be described in 
    the document, Technical Notes on Drinking Water Methods (EPA, 1994d).
        1993 EPA Inorganic Methods Manual (EPA, 1993a)  A commenter asked 
    what the differences were between Method 335.3 and the updated version, 
    Method 335.4, since both versions require manual distillation of the 
    sample to prepare it for measurement of cyanide. The technical 
    differences between these methods are minor. EPA improved the 
    automation of procedures in Method 335.4, and added the option to use a 
    labor-saving distillation procedure. The distillation option is 
    described in Method 335.4, and it is approved and described for other 
    spectrophotometric methods in Technical Notes on Drinking Water Methods 
    (EPA, 1994d).
        Two commenters objected to replacement of Method 335.3 with 335.4. 
    The objection appeared to be based on the mistaken belief that Method 
    335.4 requires a manual distillation of the sample to prepare it for 
    measurement of cyanide and that the earlier version, Method 335.3, did 
    not. EPA has never allowed spectrophotometric measurements of cyanide 
    in water samples without manual distillation of the sample using SM 
    4500-CN-C (cf. 40 CFR 136.3, Table 1B; 59 FR 4507, January 31, 1994; 
    and 57 FR 31839, July 17, 1992). Commenters may have been misled by a 
    discussion in Method 335.3 of an alternate ultraviolet (UV) digestion 
    procedure that does not require manual distillation. EPA has never 
    approved this optional UV procedure for compliance measurements of 
    cyanide, because EPA has no data to show that UV digestion would not 
    provide inaccurate results that underestimate the level of 
    contamination. To avoid manual distillation of the sample, laboratories 
    may use a selective electrode method for cyanide.
        EPA notes that the ``amenable'' spectrophotometric methods, ASTM 
    D2036-91B and SM 4500-CN-G, also require distillation prior to either 
    free or total cyanide measurements. To further clarify EPA's intent to 
    require manual distillation for all spectrophotometric determinations 
    of cyanide, these methods will be listed at 40 CFR 141.23(k) in today's 
    rule under the phrase ``Manual distillation followed by''. Immediately 
    following this phrase, the rules specify use of SM 4500-CN-C to conduct 
    this distillation.
    Microbiological Methods
        The vast majority of comments on the eighteenth edition version of 
    microbiology methods concerned the maximum time between sample 
    collection and analysis (transit time) of drinking water samples. 
    Commenters opposed reducing this time from 30 hours (16th edition of 
    Standard Methods) to 24 hours (18th edition of Standard Methods). The 
    Standard Methods committee reduced the transit time because of its 
    concern about coliform die-off in the sample over time. Commenters 
    opposed reducing the time because it would (1) be logistically 
    impractical if not impossible to do, (2) increase costs for sample 
    transport and resampling, (3) cause hardships in sample collection, and 
    (4) complicate and decrease laboratory flexibility. A few commenters 
    claimed that the reduced transit time is not supported by data.
        Coliforms usually die off over time, especially when water 
    temperatures are warm, but EPA recognizes that there is debate among 
    investigators over the rate of that decline. EPA is currently 
    conducting additional studies on this question, using fecal coliforms 
    and E. coli, and results are anticipated by the end of 1994. Given the 
    logistical and other problems that might result by decreasing the 
    transit time to 24 hours, EPA is deferring a decision on whether to 
    reduce the transit time until more data become available. For the time 
    being, the Agency has added a footnote to the Table in 
    Sec. 141.21(f)(3), allowing a maximum transit time of 30 hours. If EPA 
    decides that a reduction from 30 hours is warranted, the Agency will 
    work with the States to minimize the hardships identified in the public 
    comments. Meanwhile, EPA strongly encourages States and systems to 
    review their procedures and identify practical alternatives for 
    providing samples to laboratories more quickly.
        Other commenters objected to the requirement in the 18th edition of 
    Standard Methods to hold samples at less than 10  deg.C during transit. 
    The Standard Methods committee specified this value because of its 
    concern about coliform die-off in the sample at higher temperatures, 
    where the bacterial metabolism of coliforms and non-coliforms alike is 
    normally greater.
        Commenters objected to any EPA requirement that would require them 
    to keep samples cool during sample transit. They asserted that this 
    requirement would (1) be unnecessary and would complicate sample 
    transport logistics, (2) increase sampling costs and shipping costs for 
    both systems and laboratories, because coolers and ice packs cost money 
    and samples are heavier and thus more expensive to ship, and (3) lead 
    to problems with frozen samples or a significantly increased number of 
    invalid samples. Commenters also stated that under the presence-absence 
    concept, sample cooling was less important than under the earlier rule 
    based on coliform density.
        EPA is deferring a decision on sample transit temperature until the 
    Agency initiates a review, and possible revision, of the Total Coliform 
    Rule. For the time being, the Agency has added a footnote to the Table 
    in Sec. 141.21(f)(3) encouraging, but not requiring, systems to hold 
    samples at less than 10  deg.C during transit. Nevertheless, the Agency 
    strongly encourages systems to cool their samples during transit, 
    especially during warm summer months, to minimize coliform die-off. The 
    Agency is currently conducting additional studies on this question, 
    using fecal coliforms and E. coli, and results are anticipated by the 
    end of 1994. If EPA decides that a reduction is warranted, the Agency 
    will work with the States to minimize the hardships identified in the 
    public comments.
        EPA is also approving a new method, the Colisure test, for 
    simultaneously determining the presence of total coliforms and E. coli, 
    both of which must be monitored under the Total Coliform Rule (40 CFR 
    141.21). Data supporting the use of this method was presented in the 
    notice of July 14, 1994 (NOA).
        Most commenters supported approval of the Colisure test, but 
    several raised questions about the test, primarily concerning the 
    incubation time. They cited the Broadway et al. (1992) data that 
    indicated that only 64% and 69% of the bottles were total coliform-
    positive and E. coli-positive, respectively, after 24 hours compared to 
    the 48-hour results. According to the Broadway et al. data, 85% and 88% 
    of the bottles were total coliform-positive and E. coli-positive, 
    respectively, after 28 hours compared to the 48-hour results.
        EPA agrees with the commenters who contended that 24 hours of 
    incubation was insufficient for the Colisure test. The Agency, however, 
    believes that the recovery rate after 28 hours is reasonable, and will 
    approve the Colisure test as a 28-hour test. Moreover, based on 
    additional data from the product manufacturer showing that the false-
    positive rate after 48 hours is small, EPA will allow laboratories to 
    hold the test up to 48 hours before observing results.
    Chemical Methods
        There were only minor comments on the proposal to update chemistry 
    methods to the versions contained in the 18th edition of Standard 
    Methods. The 18th edition versions contain no or minor changes to 
    earlier versions, and EPA received no comments to document specific 
    hardships in converting to 18th edition chemical methods. Several 
    commenters noted that, although thallium is not in the scope of SM 
    3113B, EPA erroneously approved SM 3113B for thallium (57 FR 31840, 
    July 17, 1992). EPA agrees and will delete this approval in today's 
    rule.
        A commenter noted that the 18th edition version of SM 4500-Cl-G 
    omits instructions that would allow measurement of total residual 
    chlorine in drinking water samples using a colorimetric method. The 
    Standard Methods Committee has written (Eaton, 1993b) that an editorial 
    omission, not a technical change, occurred in recent versions of SM 
    4500-Cl-G. The error will be corrected in the next (19th) edition of 
    Standard Methods. EPA corrects the error today by describing the 
    omitted instructions in Technical Notes on Drinking Water Methods (EPA, 
    1994d).
    
    E. Methods To Be Withdrawn and Replaced
    
    General Comments Received on Withdrawal of Methods
        One commenter suggested that all methods carry a ``draft'' status 
    for three years after publication; other commenters asked EPA to 
    approve new methods more quickly. It would defeat EPA's intent to 
    provide modern technology quickly, if a method had to be published, 
    proposed, and then kept in draft status for three years. EPA balances 
    this problem by allowing optional use of old or new methods during a 
    transitional period, which in the case of this rule extends to July 1, 
    1996 (or 18 months after publication, whichever is later).
        Several commenters believed EPA was eliminating, or intended to 
    eliminate, all autoanalyzer or colorimetric methods. This is incorrect; 
    EPA is replacing only obsolete methods with equivalent ASTM, EPA and 
    Standard Methods. EPA is not eliminating colorimetric or autoanalyzer 
    technology for any regulated contaminant, except arsenic. Evidence of 
    EPA's intent is in the 1993 methods manual (EPA, 1993a), which updated 
    colorimetric methods for cyanide (335.4), nitrite and nitrate (353.2), 
    and sulfate (375.2). EPA has and continues to approve autoanalyzer and 
    colorimetric ASTM and Standard Methods for cyanide, fluoride, nitrite, 
    nitrate and sulfate.
        Some commenters stated that changing from EPA methods to equivalent 
    Standard Methods and ASTM methods would be very time-consuming and 
    expensive, but provided no specific information to support this 
    statement. EPA is withdrawing methods that are incomplete and often 
    require users to rely on the equivalent ASTM or Standard Methods. Thus 
    the change, in many cases, has already taken place. In other cases, 
    there are very minor differences between the withdrawn and the 
    replacement methods. EPA notes that laboratories may continue to use a 
    withdrawn method for other than compliance monitoring samples. EPA's 
    actions in today's rule save laboratories money, because they need only 
    support one version of an ASTM, EPA, or Standard Method. Prior to this 
    rule, laboratories were required to use methods in the 14th, 16th, 
    17th, and 18th editions of Standard Methods, and at least two different 
    versions of EPA Methods 200.7 and 524.2.
        EPA received numerous comments requesting an extension of the 
    withdrawal date for analytical methods. The suggested dates ranged from 
    July 1, 1995, to July 1, 2000. Based on these comments, EPA will extend 
    the methods withdrawal date from July 1, 1995, to July 1, 1996 (or 18 
    months from publication, whichever is later), which is beyond the 
    withdrawal date suggested by most commenters. New methods or new 
    versions of current methods will be approved within 30 days of 
    publication of the rule. This overlap in approval dates for new methods 
    and withdrawal of obsolete methods will give laboratories sufficient 
    time to become certified with the new methods.
    Comments on Withdrawal of Specific Methods
        Packed-Column EPA Methods Commenters generally favored withdrawal 
    of packed column methods for volatile organic compounds (VOCs) and 
    trihalomethanes (THMs), and replacing them with technologically 
    advanced capillary column methods. Additional costs incurred in 
    supporting older, obsolete methods until EPA withdraws these methods, 
    and the suitability of capillary columns to handle the increasing 
    number of regulated contaminants were cited as reasons for supporting 
    withdrawal. The July 1, 1995, withdrawal date may be too early, as 
    pointed out by some commenters. EPA will extend the date to July 1, 
    1996 (or 18 months from publication, whichever is later), to give 
    laboratories more time to plan an orderly transition to capillary 
    column methods.
        Some commenters asked EPA for continuation of the use of packed-
    column methods, if they meet current regulatory requirements. EPA feels 
    that packed-column methods have many drawbacks. For example, the cis 
    and trans dichloroethene isomers cannot be separated with the packed-
    columns specified for VOC analysis (Lyter, 1994). Such separation 
    problems with packed-column methods have limited EPA's ability to 
    prepare samples for EPA's laboratory performance evaluation (PE) 
    program. To accommodate packed-column methods, separate PE samples are 
    prepared for THMs and VOCs to minimize THM and VOC interferences that 
    users of packed column EPA methods will experience. If only capillary 
    columns are approved, EPA will have more latitude to mix VOCs and THMs 
    in PE samples to better test laboratories with concentrations and 
    mixtures of THMs and VOCs, as might realistically occur in drinking 
    waters. EPA notes that laboratories may continue to use packed column 
    methods for other than compliance monitoring analyses, such as routine 
    plant operation or source evaluation samples.
        A commenter asked why EPA proposed to withdraw THM Methods 501.1 
    and 501.2 in the 1993 proposal, but subsequently proposed to continue 
    approval of these packed column methods in the Information Collection 
    Rule (ICR) (59 FR 6354 and 6413-6414, February 10, 1994). In today's 
    rule, EPA is clarifying why and how Methods 501.1 and 501.2 can and 
    should be withdrawn without affecting analytical needs that were 
    described in the ICR proposal. In the ICR, EPA proposed Methods 501.1 
    and 501.2 only because ICR data must be gathered quickly to support 
    pending disinfectant byproduct control regulations. To support these 
    regulations, EPA proposed to conduct THM monitoring at a limited number 
    of PWS for eighteen months beginning in 1995. Since this data must be 
    collected by laboratories certified to conduct THM analyses, it could 
    be a hardship to revoke the certification of laboratories now using 
    Methods 501.1 and 501.2. EPA notes that EPA also proposed and 
    encouraged laboratories to use one of the capillary column methods (EPA 
    Methods 502.2, 524.2 and 551) to conduct THM monitoring for the ICR. 
    And in a subsequent disinfection byproduct rule (59 FR 38668, July 29, 
    1994) EPA proposed only capillary methods for THM compliance monitoring 
    (59 FR 38821).
        As explained in the 1993 proposal and in the 1992 THM methods rule 
    (58 FR 41344, August 3, 1993), EPA intends to and will withdraw packed 
    column methods for THM and VOC compliance analysis. To accommodate the 
    special and immediate information collection needs of the ICR, EPA is 
    deferring withdrawal of packed column Methods 501.1 and 501.2 until 
    July 1, 1996 (or 18 months after publication, whichever is later). This 
    date is expected to be after the beginning of the proposed ICR 
    monitoring period. When the ICR rule is promulgated, certification 
    under Methods 501.1 and 501.2 will be granted such that the withdrawal 
    date will not impede collection of THM data for the ICR.
        Colorimetric Methods for Arsenic--A commenter requested that EPA 
    not withdraw colorimetric methods for arsenic. Because the detection 
    limits of these methods are very near the MCL for arsenic, colorimetric 
    measurements do not provide a reliable indication of variability of, or 
    trends in, ambient concentrations of arsenic in the water supply when 
    these concentrations are less than the MCL. EPA believes the detection 
    limit deficiency warrants withdrawal of colorimetric methods for 
    arsenic.
        In addition, since EPA approves other methods that measure all 
    twelve regulated metals, including arsenic, it is not cost-effective to 
    measure arsenic separately with a colorimetric method. The cost of a 
    complete, broad-spectrum metals analysis by atomic absorption or ICP is 
    not reduced if arsenic is not included. And EPA knows of no situation 
    where arsenic is the only metal to be determined in a compliance 
    sample. EPA believes that there is no scientific reason or economic 
    need for a colorimetric method that only measures arsenic. However, EPA 
    notes that withdrawal of these methods does not preclude their use for 
    other than compliance monitoring samples.
        EPA Methods 208.2 and 354.1--A commenter asked EPA to replace EPA 
    Methods 208.2 (barium) and 354.1 (nitrite) with the equivalent methods 
    SM 3113B and SM 4500-NO2-B, which are published in the 18th 
    edition of Standard Methods (APHA, 1992). EPA agrees and will withdraw 
    Methods 208.2 and 354.1, since equivalent methods using the same 
    equipment and procedures are approved.
        EPA Method 340.2 (fluoride)--Commenters expressed concern that 
    withdrawal of this ion-selective electrode method will require use of 
    EPA Method 300.0, which requires purchase of an ion chromatograph. This 
    is incorrect; only the EPA ion-selective electrode method will be 
    withdrawn. The ASTM and SM methods, which use the same equipment as the 
    EPA method, are approved for fluoride compliance determinations.
        Hydrazine Methods for Nitrate and Nitrite--A commenter agreed with 
    EPA's withdrawal of hydrazine method 353.1, stating that the method is 
    obsolete. The commenter, however, wanted EPA to make available at least 
    one hydrazine method for nitrite and nitrate by approving SM 4500-
    NO3-H. EPA is withdrawing Method 353.1 because hydrazine is 
    carcinogenic and toxic, and creates a significant hazardous waste 
    disposal problem. SM 4500-NO3-H has the same problems and, 
    therefore, cannot be approved. EPA believes users of hydrazine methods 
    will be able to convert easily to the approved cadmium reduction 
    methods for nitrate and nitrite by changing their reagent from 
    hydrazine to cadmium when their supply of hydrazine is depleted. The 
    cadmium methods, which have been approved for nitrate and nitrite since 
    1991, use the same equipment as the hydrazine methods.
        Flame AA for metals--Three commenters requested that flame atomic 
    absorption (AA) and graphite furnace methods not be withdrawn. EPA has 
    not withdrawn flame AA and graphite furnace methods published by ASTM 
    or Standard Methods; only the obsolete EPA versions of these methods 
    are withdrawn.
        Direct Aspiration Flame AA Methods--Some commenters wanted EPA to 
    expand the scope of these methods to include metals other than barium 
    and nickel. EPA cannot expand the scope, because the methods are not 
    sensitive enough to measure metals other than barium and nickel.
        Method 515.1--EPA received many comments requesting that this 
    method not be withdrawn, primarily for two reasons. First, neither 
    proposed replacement method, 552.1 or 515.2, covers all of the 
    regulated chemicals that are in Method 515.1. Secondly, the new dalapon 
    method (552.1) requires significantly different equipment, procedures 
    and skills than Method 515.1. Four commenters agreed with EPA's 
    proposal to withdraw Method 515.1, because a combination of Methods 
    515.2 and 552.1 meets their regulatory needs. EPA agrees with the 
    majority of commenters and will not withdraw Method 515.1.
        Methods for Secondary Contaminants--Some commenters believed that 
    delisting a secondary contaminant method precludes its use for other 
    than compliance monitoring samples. This is not correct; EPA does not 
    certify laboratories for secondary monitoring, and EPA only recommends 
    methods for secondary contaminants. Unless State requirements provide 
    otherwise, laboratories may use methods other than those cited at 40 
    CFR 143.4(b) for measurement of secondary contaminants.
        EPA Method 245.2 (mercury)--EPA was asked to withdraw this method, 
    which is an automated, cold vapor method for mercury. EPA cannot 
    withdraw this method because there is no other equivalent version of 
    the method. Because EPA does not have enough information to assess the 
    effect that withdrawal of Method 245.2 would have, it is deferring a 
    decision on withdrawal.
        EPA Methods 150.1, 150.2 (pH)--In the 1994 NOA, EPA proposed to 
    replace these methods with equivalent ASTM and Standard Methods for pH. 
    A commenter noted that the EPA methods are easier to use under field 
    conditions. The commenter indicated that since many pH measurements are 
    made in the field at the point of sample collection, withdrawal of the 
    EPA methods would pose a significant hardship. EPA agrees with the 
    commenter, and will not withdraw these methods until ASTM or Standard 
    Methods pH methods are simplified for field use.
    
    F. Miscellaneous
    
        Reformat Listing of Methods in 40 CFR Parts 141 and 143--Commenters 
    have asked EPA to improve the organization and clarity of the drinking 
    water regulations. Commenters have criticized the organization of the 
    rules, and noted difficulty in obtaining copies of drinking water 
    regulations. They need the regulations, because they contain tables and 
    lists of approved methods, and because mandatory method instructions 
    are included in the text of the rules and in footnotes to the tables of 
    methods. These instructions are not contained in the approved methods, 
    because they were developed after the method was published. In today's 
    rule, EPA is minimizing the use of footnotes and lengthy technical 
    instructions in drinking water rules. EPA is accomplishing this by 
    including these instructions in the document Technical Notes on 
    Drinking Water Methods (EPA, 1994d). This EPA publication contains 
    mandatory procedures, clarifications and helpful options, such as 
    guidance on more efficient ways to conduct asbestos and dioxin 
    compliance measurements. EPA will place these instructions in the 
    affected method when the method is revised and published. EPA intends 
    to use this document to publish future method corrections or 
    modifications (after notice and comment in the Federal Register as 
    necessary). EPA believes Technical Notes will be easier for users to 
    obtain, read and photocopy than the tables of approved methods in the 
    drinking water rules. Incorporating Technical Notes on Drinking Water 
    Methods by reference in the rule has the effect of making its 
    provisions as mandatory as those in the approved drinking water 
    methods.
        EPA is improving the clarity of the rules by consolidating listings 
    of analytical methods. Analytical methods for THMs have been moved from 
    Sec. 141.30 to Sec. 141.24(e). Appendix C of Sec. 141.30, which 
    contained THM Methods 501.1 and 501.2, is withdrawn immediately, but 
    the methods may be used for compliance monitoring under Sec. 141.30 
    until July 1, 1996 (or 18 months from publication, whichever is later). 
    And analytical methods formerly specified for lead, copper, and 
    corrosivity at 40 CFR 141.89(a) and sodium at Sec. 141.41(d) are now 
    listed with other inorganic methods at Sec. 141.23(k)(1). EPA notes 
    that although sodium was removed from the list of 83 contaminants 
    included in the 1986 amendments to the SDWA (53 FR 26487), the 
    provisions at Sec. 141.41 still obtain.
        Specifications for Continuous Chlorine Monitoring Methods--
    Commenters favored the proposed specification for continuous chlorine 
    monitoring measurements to be based on calibration with an approved 
    grab sample method. Two commenters asked EPA to extend the calibration 
    period to seven days. EPA has no data to support such an extension. 
    However, the EPA protocol for continuous chlorine monitoring allows a 
    laboratory to use an alternative protocol, if it is approved by the 
    State. EPA believes it is prudent for States to monitor and approve 
    changes to the EPA protocol, such as those suggested by commenters. The 
    protocol approved in today's rule is specified at 40 CFR 141.74(a)(2), 
    and allows States to grant variations, including certain changes in the 
    chemistry of the method.
        Allow Interchange of Detectors in EPA Methods 505, 507, 508--
    Commenters favored this proposal. Two commenters noted that data with 
    alternative detectors must be verified, and were concerned about poor 
    ECD response of some nitrogen-containing compounds. EPA agrees that 
    data must be verified when changing detectors, and that the results for 
    all chemicals in Methods 505, 507 or 508 may not meet quality control 
    requirements when an alternative detector is used. This is why Section 
    6.8.3 of Methods 507 and 508, and Section 10.4 of Methods 505, 507 and 
    508 allow alternative detectors only if the initial demonstration of 
    capability criteria in Section 10 of each method is met by the 
    alternative detector.
        One commenter wanted to allow use of other detectors with EPA 
    Method 504. EPA cannot approve this request, because EPA has no data to 
    justify use of alternative detectors in Methods 504 or 504.1, which use 
    an electron capture detector (ECD). The ECD has been the only detector 
    capable of routinely measuring EDB and DBCP at the required parts-per-
    trillion concentrations (56 FR 3550, January 30, 1991).
        Guidance on Preserving Samples--A commenter asked that biocide 
    procedures be dropped from the VOC methods, because EPA has dropped 
    mercuric chloride as a biocide in synthetic organic chemical (SOC) 
    methods. EPA dropped mercuric chloride from SOC methods, because EPA 
    has no data to show that biodegradation of a regulated SOC occurs in a 
    typical drinking water sample, and because mercuric chloride is toxic 
    and a hazardous waste. However, EPA has data to show degradation (EPA, 
    1994e) in samples collected for measurement of VOCs. The biocide 
    procedures required in the VOC methods require some combination of 
    chilling, rapid transit and analysis, or acidification. None of these 
    procedures pose health or waste disposal problems that compare with the 
    problems associated with preservation using mercuric chloride. 
    Therefore, EPA continues to require use of a biocide in VOC methods.
        Liquid-Solid Extraction (LSE) in EPA Methods 507 and 508--Some 
    commenters believed more data were needed before EPA allowed use of LSE 
    in Methods 507 and 508; EPA agrees. EPA stated in the December proposal 
    that ``the Agency regards this proposed modification as tentative and 
    will base a final decision on whether to approve on public comment and 
    additional EPA performance data.'' After studying this option and 
    developing additional data (EPA, 1994e), EPA has decided not to add LSE 
    as an option in Methods 507 and 508, because EPA does not have data to 
    support use of this technique for all of the chemicals in the methods. 
    As an alternative, EPA has developed and is approving Method 508.1 
    (EPA, 1994c). Method 508.1 uses the procedures and the electron capture 
    detector that are used in Method 508, and it allows use of LSE. The 
    scope of Method 508.1 covers many of the Method 507 and 508 analytes 
    that are subject to regulated or unregulated contaminant monitoring 
    requirements, but it does not include butachlor, PCBs or toxaphene. In 
    today's rule EPA will approve Method 508.1 for measurement of alachlor, 
    atrazine, chlordane, endrin, heptachlor, heptachlor epoxide, 
    hexachloro-benzene, hexachlorocyclopentadiene, lindane, methoxychlor, 
    and simazine, which are regulated SOCs. It is also approved for aldrin, 
    dieldrin, metolachlor, metribuzin, and propachlor, which are 
    unregulated SOCs.
        Methods for Other Contaminants--In the 1993 proposal EPA provided 
    guidance to systems that wish to measure chemicals that are not 
    regulated, and need advice on what method to use. The guidance stated 
    that ``although EPA approves methods only for contaminants regulated 
    under the Safe Drinking Water Act, the Agency encourages laboratories 
    to use these methods for other contaminants if the method description 
    specifically includes these contaminants.'' One commenter mistakenly 
    believed that this eliminates the use of other methods or techniques, 
    such as test kits. Although EPA encourages laboratories to save money 
    by using a compliance method to measure all chemicals of interest that 
    are in the analytical scope of the method, this does not preclude 
    systems from using other methods, including test kits, for samples 
    other than compliance monitoring samples.
        EPA cautions users to carefully evaluate the performance of a 
    method when using it for samples other than compliance monitoring 
    samples or for contaminants not regulated under the SDWA. For example, 
    EDB and DBCP appear in the scope of EPA Methods 504.1, 502.2, 524.2 and 
    551. However, Methods 502.2 and 524.2 are not approved for compliance 
    analyses, because they do not have the sensitivity to measure 
    compliance with the EDB and DBCP MCLs.
        Methods Approval Process--Several commenters believe that the 
    process of proposing and approving methods or method modifications will 
    always be too slow to accommodate the technical and certification needs 
    of the laboratory community. To solve this problem, commenters asked 
    EPA to specify performance criteria in drinking water rules, or in the 
    approved methods. The purpose of this would be to allow laboratories to 
    use any analytical method, provided it met the mandatory criteria. EPA 
    agrees that the present methods approval system is slow. To solve this 
    problem, EPA and other organizations are seeking to consolidate methods 
    across regulatory programs and media, and to write generic method 
    performance criteria (EPA, 1994g). A performance-based method system, 
    as suggested by commenters, might be part of the final solution. There 
    are two groups working on this problem. The groups are the 
    Intergovernmental Task Force on Monitoring, and EPA's Environmental 
    Monitoring Management Council. A recommendation of these groups may be 
    for EPA to propose a new method approval and method-writing protocol. 
    The protocol would be designed to expedite approval of drinking water 
    method modifications while maintaining the degree of control needed to 
    ensure effective enforcement of drinking water regulations.
        Field and Test Kits--Two commenters noted an omission in the rule 
    text in the 1993 proposal that appears to eliminate an important 
    option. This option allows States to approve use of DPD colorimetric 
    test kits for measurement of chlorine residuals. EPA did not intend to 
    eliminate this option, and agrees the wording in the 1993 proposal (58 
    FR 65631) may be misleading. Today's rule clearly allows use of the DPD 
    kits, provided the State also approves use of the kits. This option is 
    specified at 40 CFR 141.74(a)(2).
        A commenter asked EPA to approve field kits for pH, and methods for 
    continuous monitoring of pH and residual chlorine. EPA does not need to 
    approve field methods for pH because currently, analysis with an 
    approved pH method may be conducted in the field or in the laboratory. 
    Regarding continuous monitoring methods, in today's rule, EPA provides 
    criteria for continuous monitoring of chlorine residuals (40 CFR 
    141.74(a)(2)). Since EPA does not require continuous pH monitoring, EPA 
    does not approve or disapprove methods for continuous measurement of 
    pH.
        Turbidity--A commenter asked that turbidity measurements, which are 
    specified in the drinking water regulations, be waived if no 
    particulate or cloudiness is visible to the analyst. The present 
    requirement is that turbidity be measured in all samples, and that 
    digestion be performed if the turbidity is one NTU or greater. EPA 
    cannot waive turbidity measurements on samples that appear to be clear, 
    because samples with turbidity of up to three NTU can appear clear to 
    the unaided eye.
        Corrosivity--One commenter noted the proposed rule made no 
    reference to updating the methods for corrosivity in 40 CFR 141.42(c). 
    These methods were published in 1980 and 1982 (45 FR 57346, August 27, 
    1980 and 47 FR 10999, March 12, 1982). In the Lead and Copper Rule (56 
    FR 26460, June 7, 1991), EPA agreed that corrosion control strategies 
    could be developed or evaluated by measuring alkalinity and other 
    parameters (56 FR 26489 and 26496). However, the Lead and Copper Rule 
    did not update or specify use of the methods in 40 CFR 141.42(c). 
    Instead, more current methods were specified in 40 CFR 141.89(a) (56 FR 
    26509-26510). In today's rule, EPA eliminates possible confusion 
    between the requirements in 40 CFR 141.89 and 141.42 by removing 
    subparagraphs 40 CFR 141.42(a)-(c).
        New Technologies--Comments were received asking the Agency to 
    evaluate and develop methods based on new technologies, such as 
    bioassay, ELISA, and capillary electrophoresis. The Agency continues to 
    incorporate new technologies in methods, and appreciates the many 
    articles that were sent to draw attention to new technologies. In the 
    last twenty years, the Agency has aided the development of the mass 
    spectrometer into a powerful and routine analytical instrument. With 
    suggestions from the laboratory community (56 FR 3550, January 30, 
    1991), the Agency moved from packed to capillary column gas 
    chromatographic technology, and expects to adopt innovative procedures 
    and instruments in future methods.
        In the 1993 proposal, EPA invited public suggestions that EPA might 
    consider approving in this rule or in a later rulemaking. This 
    invitation was not meant to imply that new methods or method 
    modifications submitted as suggestions would or could bypass 
    requirements that are specified at 40 CFR 141.27. Some commenters 
    expressed interest in having their method or instrumentation included 
    in EPA-approved methods. EPA suggests that these commenters submit 
    their data to EPA's Alternative Test Procedures (ATP) program for 
    evaluation. A method or instrument can be considered for approval by 
    EPA after it has received a favorable evaluation under the ATP program. 
    A protocol for submitting ATP data is available from EPA (EPA, 1993c).
    
    V. Availability and Sources for Methods Information
    
        Commenters requested help in obtaining copies of analytical methods 
    cited in drinking water rules. Sources of all approved methods are 
    contained in the References section of this rule. These methods are 
    available for review but not distribution at the EPA Drinking Water 
    Docket (MC 4101), 401 M Street SW., Washington, DC 20460. For access to 
    the docket material, please call (202) 260-3027 between 9 am and 3:30 
    pm, EST, Monday through Friday, excluding federal holidays. EPA only 
    stocks or distributes copies of methods published by EPA. All other 
    methods must be obtained from the publisher. Sources (with addresses) 
    for all approved methods are cited at 40 CFR Parts 141 and 143, and in 
    the References section of today's rule. Most EPA methods and the 
    document, Technical Notes on Drinking Water Methods, may be purchased 
    from the National Technical Information Service (NTIS), U.S. Department 
    of Commerce, 5285 Port Royal Road, Springfield, VA 22161. The toll-free 
    number is: (800) 553-6847, local: (703) 487-4650. Refer to the drinking 
    water rules or the References section of this rule to obtain the NTIS 
    order number and purchase information, or contact the Safe Drinking 
    Water hotline. The hotline operates from 9 a.m. and 5:30 p.m. EST, 
    Monday through Friday, excluding federal holidays. The toll-free number 
    is (800) 426-4791. EPA Methods 504.1, 508.1 and 525.2 are not published 
    in an NTIS manual. These methods may be obtained directly from EPA, 
    Environmental Monitoring Systems Laboratory, Cincinnati, OH 45268; the 
    phone number is (513) 569-7586. Since Methods 150.1 (pH), 150.2 (pH) 
    and 245.2 (mercury) are published in ``Methods for Chemical Analysis of 
    Water and Wastes'' (EPA, 1983a), owners of this EPA manual do not need 
    to reorder these methods.
        EPA believes most laboratories will need only the more recently 
    published or approved methods that are listed in today's rule. These 
    methods (or manuals) are as follows. Technical Notes on Drinking Water 
    Methods, October 1994, NTIS PB95-104766; EPA Method 508.1, 
    ``Determination of Chlorinated Pesticides, Herbicides, and 
    Organohalides in Water Using Liquid-Solid Extraction and Electron 
    Capture Gas Chromatography'', October 1994; EPA Method 100.2, 
    ``Determination of Asbestos Structures over 10m in Length in 
    Drinking Water'', June 1994, NTIS PB94- 201902; ``Methods for the 
    Determination of Metals in Environmental Samples--Supplement I'', May 
    1994, NTIS PB94-184942; EPA Method 525.2, ``Determination of Organic 
    Compounds in Drinking Water by Liquid-Solid Extraction in Capillary 
    Column Gas Chromatography/Mass Spectrometry'', March 1994; EPA Method 
    504.1, ``1,2-Dibromoethane (EDB), 1,2-Dibromo-3-chloropropane (DBCP), 
    and 1,2,3-Trichloropropane (123TCP) in Water by Microextraction and Gas 
    Chromatography'', 1993; ``Methods for the Determination of Inorganic 
    Substances in Environmental Samples'', August 1993, NTIS PB91-231498; 
    ``Methods for the Determination of Organic Compounds in Drinking 
    Water--Supplement II,'' August 1992, NTIS PB92- 207703; Standard 
    Methods for the Examination of Water and Wastewater 18th Edition 
    Supplement, 1994; Colisure, Millipore Corp., 1994; and GLI Method 2, 
    ``Turbidity'', Great Lakes Instruments, Inc., November 2, 1992.
        The American Society for Testing and Materials (ASTM) annually 
    reprints all of the methods contained in the Annual Book of ASTM 
    Methods, even methods that have not been editorially or technically 
    revised. Thus, it is permissible to use any edition that contains the 
    EPA-approved version of the compliance method. EPA notes that Orion 
    Method 601 ``Standard Method of Test for Nitrate in Drinking Water'', 
    which is equivalent to SM 4500-NO3-D (APHA, 1992), is 
    identical to Orion Method WeWWG/5880. Method WeWWG/5880 is approved for 
    nitrate analysis. ATI Orion republished the method in 1994 and 
    renumbered it as 601, because the 1985 manual ``Orion Guide to Water 
    and Wastewater Analysis'', which contained WeWWG/5880, is no longer 
    available. In today's rule EPA cites WeWWG/5880 as 601 at 40 CFR 
    141.23(k)(1).
    
    VI. Regulation Assessment Requirements
    
    A. Executive Order 12866
    
        Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
    Agency must determine whether the regulatory action is ``significant'' 
    and therefore subject to OMB review and the requirements of the 
    Executive Order. The Order defines ``significant regulatory action'' as 
    one that is likely to result in a rule that may:
        (1) Have an annual effect on the economy of $100 million or more, 
    or adversely affect in a material way the economy, a sector of the 
    economy, productivity, competition, jobs, the environment, public 
    health or safety, or State, local, or tribal governments or 
    communities;
        (2) Create a serious inconsistency or otherwise interfere with an 
    action taken or planned by another agency;
        (3) Materially alter the budgetary impact of entitlements, grants, 
    user fees, or loan programs or the rights and obligations of recipients 
    thereof; or
        (4) Raise novel legal or policy issues arising out of legal 
    mandates, the President's priorities, or the principles set forth in 
    the Executive Order.
        It has been determined that this rule is not a ``significant 
    regulatory action'' under the terms of Executive Order 12866 and is 
    therefore not subject to OMB review.
    
    B. Regulatory Flexibility Act
    
        The Regulatory Flexibility Act requires EPA to explicitly consider 
    the effect of these regulations on small entities. By policy, EPA has 
    decided to consider regulatory alternatives if there is any economic 
    impact on any number of small entities.
        This rule is consistent with the objectives of the Regulatory 
    Flexibility Act because it will not have any economic impact on any 
    small entities. This rule specifies analytical methods that 
    laboratories must use for testing regulated drinking water 
    contaminants. Monitoring requirements were promulgated in earlier 
    notices. The rule would require laboratories to use the most recent 
    version of a method and imposes no additional requirements. It is 
    actually expected to reduce cost of analysis by eliminating current 
    requirements to use different versions of the same method, and by 
    allowing more contaminants to be analyzed simultaneously by using a 
    single method. Therefore, the Agency believes that this notice would 
    have no adverse effect on any number of small entities.
    
    C. Paperwork Reduction Act
    
        The rule contains no requests for information and consequently is 
    not subject to the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
    
    D. Science Advisory Board, National Drinking Water Advisory Council, 
    and Secretary of Health and Human Services
    
        In accordance with section 1412(d) and (e) of the SDWA, the Agency 
    consulted with the Science Advisory Board, the National Drinking Water 
    Advisory Council, and the Secretary of Health and Human Services on 
    this action and took their comments into account.
    
    VII. References
    
    APHA. 1992. Eighteenth edition of Standard Methods for the 
    Examination of Water and Wastewater, 1992, American Public Health 
    Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.
    APHA. 1994. Method 6610 ``Carbamate Pesticides'' in Standard Methods 
    for the Examination of Water and Wastewater, 18th Edition 
    Supplement, 1994, American Public Health Association, 1015 Fifteenth 
    Street NW, Washington, D.C. 20005. APHA.
    ASTM. 1994. Annual Book of ASTM Methods, 1994, Vol. 11.01 and 11.02, 
    American Society for Testing and Materials, 1916 Race Street, 
    Philadelphia, PA 19103.
    Bionetics. Report from Kenneth W. Edgell, et al., ``Determination of 
    Inorganic Anions in Water by Ion Chromatography: Collaborative 
    Study'', Bionetics Corp., 16 Triangle Park Drive, Cincinnati, Ohio 
    45246, 1991.
    Broadway, S., B. Pyle, G. McFeters. 1992. Final report of 
    equivalency testing for Colisure. Montana State University, Bozeman, 
    MT.
    Eaton. 1993a. Letter from Andrew D. Eaton, Standard Methods 
    Committee, ``Error in 4500-Cl E'', American Public Health 
    Association, 1015 Fifteenth Street NW, Washington, D.C. 20005, June 
    4, 1993.
    Eaton. 1993b. Letter from Andrew D. Eaton, Standard Methods 
    Committee, ``Inquiry on Chlorine Residual 4500-Cl (18th Edition)'', 
    American Public Health Association, 1015 Fifteenth Street NW, 
    Washington, D.C. 20005, October 26, 1993.
    EPA. 1974. Method 245.2, ``Mercury, Automated Cold Vapor 
    Technique'', EPA, Environmental Monitoring Systems Laboratory, 
    Cincinnati, OH 45268, 1974. Also contained in reference EPA, 1983a.
    EPA. 1978. Method 150.1, ``pH, Electrometric'', EPA, Environmental 
    Monitoring Systems Laboratory, Cincinnati, OH 45268, 1978. Also 
    contained in reference EPA, 1983a.
    EPA. 1982. Method 150.2, ``pH Continuous Monitoring, Electro-
    metric'', EPA, Environmental Monitoring Systems Laboratory, 
    Cincinnati, OH 45268, December 1982. Also contained in reference 
    EPA, 1983a.
    EPA. 1983a. ``Methods for Chemical Analysis of Water and Wastes'', 
    EPA, March 1983, NTIS PB84-128677.
    EPA. 1983b. Method 100.1, ``Analytical Method for the Determination 
    of Asbestos Fibers in Water'', September 1983, NTIS PB83-260471.
    EPA. 1990a. ``Methods for the Determination of Organic Compounds in 
    Drinking Water--Supplement I'', July 1990, NTIS PB91-146027.
    EPA. 1990b. Manual for the Certification of Laboratories Analyzing 
    Drinking Water, Third Edition, Office of Water Resource Center (RC-
    4100), 401 M. Street S.W., Washington, D.C. 20460, EPA 570-9-90-008, 
    April 1990.
    EPA. 1991. ``Methods for the Determination of Organic Compounds in 
    Drinking Water'', December 1988, revised July 1991, NTIS PB91-
    231480.
    EPA. 1992a. Memorandum from Richard L. Carr, ``Second Laboratory 
    Validation of Method 555'', December 10, 1992, U.S. Environmental 
    Protection Agency.
    EPA. 1992b. ``Methods for the Determination of Organic Compounds in 
    Drinking Water--Supplement II,'' August 1992, NTIS PB92-207703.
    EPA. 1993a. ``Methods for the Determination of Inorganic Substances 
    in Environmental Samples'', August 1993, NTIS PB94-121811.
    EPA. 1993b. Memorandum from James R. Elder, ``Detection Limits in 
    Compliance Monitoring'', December 16, 1993, U.S. Environmental 
    Protection Agency.
    EPA. 1993c. ``Protocol for Nationwide Approval of New or Revised 
    Methods'', Rev. 1.4, EPA, Environmental Monitoring Systems 
    Laboratory, Cincinnati, OH 45268, July 14, 1993.
    EPA. 1993d. Method 504.1, ``1,2-Dibromoethane (EDB), 1,2-Dibromo-3-
    chloropropane (DBCP), and 1,2,3-Trichloropropane (123TCP) in Water 
    by Microextraction and Gas Chromatography'', EPA, Environmental 
    Monitoring Systems Laboratory, Cincinnati, OH 45268, 1993.
    EPA. 1994a. ``Methods for the Determination of Metals in 
    Environmental Samples--Supplement I'', May 1994, NTIS PB94-184942.
    EPA. 1994b. Method 525.2, Rev. 1.0, ``Determination of Organic 
    Compounds in Drinking Water by Liquid-Solid Extraction in Capillary 
    Column Gas Chromatography/Mass Spectrometry'', EPA, Environmental 
    Monitoring Systems Laboratory, Cincinnati, OH 45268, March 1994.
    EPA. 1994c. Method 508.1, Rev. 1.0, ``Determination of Chlorinated 
    Pesticides, Herbicides, and Organohalides by Liquid-Solid Extraction 
    and Electron Capture Gas Chromatography'', EPA, Environmental 
    Monitoring Systems Laboratory, Cincinnati, OH 45268, 1994.
    EPA. 1994d. Technical Notes on Drinking Water Methods, EPA-600/R-94-
    173, October 1994, NTIS PB95-104766.
    EPA. 1994e. ``Response to Comments on December 15, 1993, Analytical 
    Methods Proposal, 58 FR 65622'', Office of Water Docket (MC 4601), 
    401 M. St. S.W., Washington, D.C. 20460, October 1994.
    EPA. 1994f. Memorandum from Mary Ann Feige, et al., ``Detection 
    Limits in the Regulations'', March 11, 1994, U.S. Environmental 
    Protection Agency.
    EPA. 1994g. Memorandum from Robert M. Sussman, ``EMMC Activities'', 
    May 13, 1994, U.S. Environmental Protection Agency.
    EPA. 1994h. Method 100.2, ``Determination of Asbestos Structures 
    over 10m in Length in Drinking Water'', June 1994, NTIS 
    PB94-201902.
    EPA. 1994i. Method 1613: ``Tetra-through Octa-Chlorinated Dioxins 
    and Furans by Isotope-Dilution HRGC/HRMS'', October 1994, NTIS PB95-
    104774.
    Great Lakes. GLI Method 2, ``Turbidity'', Great Lakes Instruments, 
    Inc., 8855 North 55th Street, Milwaukee, WI 53223, November 2, 1992.
    Lyter. Letter from P. Ted Lyter, Dept. of Environmental Resources, 
    Commonwealth of Pennsylvania, P.O. Box 1467, Harrisburg, PA 17105-
    1467, January 12, 1994.
    Millipore. ``Waters Test Method for Determination of Nitrite/Nitrate 
    in Water Using Single Column Ion Chromatography'', Method B-1011, 
    Millipore Corporation, Waters Chromatography Division, 34 Maple 
    Street, Milford, MA 01757.
    Millipore. 1994. Colisure Presence/Absence Test for Detection and 
    Identification of Coliform Bacteria and Escherichia coli in Drinking 
    Water. February 28, 1994. Millipore Corp., Technical Services 
    Department, 80 Ashby Road, Bedford, MA 01730.
    Orion. Technical Bulletin 601, ``Standard Method of Test for Nitrate 
    in Drinking Water'', PN 221890-001, ATI Orion, 529 Main Street, 
    Boston, MA 02129, July 1994.
    Technicon. 1972. Industrial Method No. 129-71W, ``Fluoride in Water 
    and Wastewater'', Technicon Industrial Systems, Tarrytown, NY 10591, 
    December 1972.
    Technicon. 1989. Method No. 380-75WE, ``Fluoride in Water and 
    Wastewater'', Technicon Industrial Systems, Tarrytown, NY 10591, 
    February 1976.
    USGS. 1989. Methods I-3720-85, I-3300-85, I-1030-85, I-1601-85, I-
    2598-85, I-1700-85 and I-2700-85 in Techniques of Water Resources 
    Investigations of the U.S. Geological Survey, Book 5, Chapter A-1, 
    3rd ed., U.S. Geological Survey, Books and Open File Reports 
    Section, Box 25425, Federal Center, Denver, CO 80225-0425, 1989.
    USGS. 1993. Method I-2601-90 in Methods of Analysis by the U.S. 
    Geological Survey National Water Quality Laboratory--Determination 
    of Inorganic and Organic Constituents in Water and Fluvial 
    Sediments, Open File Report 93-125, U.S. Geological Survey, Books 
    and Open File Reports Section, Box 25425, Federal Center, Denver, CO 
    80225-0425, 1993.
    
    List of Subjects
    
    40 CFR Part 141
    
        Environmental Protection, Chemicals, Incorporation by reference, 
    Intergovernmental relations, Water supply.
    
    40 CFR Part 143
    
        Chemicals, Incorporation by reference, Intergovernmental relations, 
    Water supply.
    
        Dated: November 25, 1994.
    Carol M. Browner,
    Administrator.
        For the reasons set out in the preamble, parts 141 and 143 of title 
    40, Code of Federal Regulations, are amended as follows:
    
    PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS
    
        1. The authority citation for part 141 continues to read as 
    follows:
    
        Authority: 42 U.S.C. 300f, 300g-1, 300g-2 300g-3, 300g-4, 300g-
    5, 300g-6, 300j-4, 300j-9.
    
        2. Section 141.21 is amended by revising paragraph (f)(3), removing 
    and reserving (f)(4), revising the next to last sentence of (f)(5), 
    revising the second sentence of (f)(6)(i), revising the second sentence 
    of (f)(6)(ii), Adding (F)(6)(iv), and adding a new sentence as the next 
    to last sentence in (f)(8) to read as follows:
    
    
    Sec. 141.21  Coliform sampling.
    
    * * * * *
        (f) * * *
        (3) Public water systems must conduct total coliform analyses in 
    accordance with one of the analytical methods in the following table. 
    These methods are contained in the 18th edition of Standard Methods for 
    the Examination of Water and Wastewater, 1992, American Public Health 
    Association, 1015 Fifteenth Street NW., Washington, DC 20005. A 
    description of the Colisure Test may be obtained from the Millipore 
    Corporation, Technical Services Department, 80 Ashby Road, Bedford, MA 
    01730. The toll-free phone number is (800) 645-5476.
    
    ------------------------------------------------------------------------
             Organism                   Methodology             Citation    
    ------------------------------------------------------------------------
    Total Coliforms1..........  Total Coliform              9221A, B.       
                                 Fermentation                               
                                 Technique2,3,4.                            
                                Total Coliform Membrane     9222A, B, C.    
                                 Filter Technique.                          
                                Presence-Absence (P-A)      9221D.          
                                 Coliform Test4,5.                          
                                ONPG-MUG Test6............  9223.           
                                Colisure Test7............                  
    ------------------------------------------------------------------------
    \1\The time from sample collection to initiation of analysis may not    
      exceed 30 hours.                                                      
    \2\Lactose broth, as commercially available, may be used in lieu of     
      lauryl tryptose broth, if the system conducts at least 25 parallel    
      tests between this medium and lauryl tryptose broth using the water   
      normally tested, and this comparison demonstrates that the false-     
      positive rate for total coliforms, using lactose broth, is less than  
      10 percent.                                                           
    \3\If inverted tubes are used to detect gas production, the media should
      cover these tubes at least one-half to two-thirds after the sample is 
      added.                                                                
    \4\No requirement exists to run the completed phase on 10 percent of all
      total coliform-positive confirmed tubes.                              
    \5\Six-times formulation strength may be used if the medium is filter-  
      sterilized rather than autoclaved.                                    
    \6\The ONPG-MUG Test is also known as the Autoanalysis Colilert System. 
    \7\The Colisure Test must be incubated for 28 hours before examining the
      results. If an examination of the results at 28 hours is not          
      convenient, then results may be examined at any time between 28 hours 
      and 48 hours.                                                         
    
        (4) [Reserved]
        (5) * * * The preparation of EC medium is described in the 18th 
    edition of Standard Methods for the Examination of Water and 
    Wastewater, 1992, Method 9221E--p. 9-52, paragraph 1a. * * *
        (6) * * *
        (i) * * * EC medium is described in the 18th edition of Standard 
    Methods for the Examination of Water and Wastewater, 1992, Method 
    9221E--p. 9-52, paragraph 1a. * * *
        (ii) * * * Nutrient Agar is described in the 18th edition of 
    Standard Methods for the Examination of Water and Wastewater, 1992, p. 
    9-47 to 9-48.
        (iii) * * *
        (iv) The Colisure Test. A description of the Colisure Test may be 
    obtained from the Millipore Corporation, Technical Services Department, 
    80 Ashby Road, Bedford, MA 01730.
    * * * * *
        (8) * * * A description of the Colisure Test may be obtained from 
    the Millipore Corp., Technical Services Department, 80 Ashby Road, 
    Bedford, MA 01730. * * *
    * * * * *
        3. Section 141.22(a) is amended by removing the next to last 
    sentence and revising the last sentence to read as follows:
    
    
    Sec. 141.22  Turbidity sampling and analytical requirements.
    
    * * * * *
        (a) * * * Turbidity measurements shall be made as directed in 
    Sec. 141.74(a)(1).
    * * * * *
        4. Section 141.23 is amended by removing paragraph (k)(2) and 
    redesignating paragraph (k)(4) as (k)(2), by removing paragraph (k)(3) 
    and redesignating paragraph (k)(5) as (k)(3), by removing and reserving 
    paragraph (q), and revising paragraph (k)(1) to read as follows:
    
    
    Sec. 141.23  Inorganic chemical sampling and analytical requirements.
    
    * * * * *
        (k) * * *
        (1) Analysis for the following contaminants shall be conducted in 
    accordance with the methods in the following Table, or their equivalent 
    as determined by EPA. Criteria for analyzing arsenic, barium, 
    beryllium, cadmium, calcium, chromium, copper, lead, nickel, selenium, 
    sodium, and thallium with digestion or directly without digestion, and 
    other analytical test procedures are contained in Technical Notes on 
    Drinking Water Methods, EPA-600/R-94-173, October 1994. This document 
    also contains approved analytical test methods which remain available 
    for compliance monitoring until July 1, 1996. These methods will not be 
    available for use after July 1, 1996. This document is available from 
    the National Technical Information Service, NTIS PB95-104766, U.S. 
    Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 
    22161. The toll-free number is 800-553-6847.
    
    ----------------------------------------------------------------------------------------------------------------
         Contaminant        Methodology        EPA             ASTM\3\                SM\4\               Other     
    ----------------------------------------------------------------------------------------------------------------
    Antimony............  ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Hydride-Atomic   ...........  D-3697-92                                                   
                           Absorption.                                                                              
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  ....................  3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Arsenic.............  Inductively         \2\200.7  ....................  3120B...............                  
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  D-2972-93C            3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
                          Hydride Atomic   ...........  D-2972-93B            3114B...............                  
                           Absorption.                                                                              
    Asbestos............  Transmission        \9\100.1                                                              
                           Electron                                                                                 
                           Microscopy.                                                                              
                          Transmission       \10\100.2                                                              
                           Electron                                                                                 
                           Microscopy.                                                                              
    Barium..............  Inductively         \2\200.7  ....................  3120B...............                  
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic           ...........  ....................  3111D...............                  
                           Absorption;                                                                              
                           Direct.                                                                                  
                          Atomic           ...........  ....................  3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Beryllium...........  Inductively         \2\200.7  ....................  3120B...............                  
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  D-3645-93B            3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Cadmium.............  Inductively         \2\200.7                                                              
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  ....................  3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Chromium............  Inductively         \2\200.7  ....................  3120B...............                  
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  ....................  3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Cyanide.............  Manual           ...........  ....................  4500-CN-C...........                  
                           Distillation                                                                             
                           followed by.                                                                             
                          Spectrophotomet  ...........  D2036-91B             4500CN-G............                  
                           ric, Amenable.                                                                           
                          Spectrophotomet  ...........  D2036-91A             4500-CN-E...........  \5\I-3300-85    
                           ric Manual.                                                                              
                          Semi-automated.     \6\335.4                                                              
                          Selective        ...........  ....................  4500CN-F............                  
                           Electrode.                                                                               
    Fluoride............  Ion                 \6\300.0  D4327-91              4110B...............                  
                           Chromatography.                                                                          
                          Manual           ...........  ....................  4500F-B,D...........                  
                           Distill.;                                                                                
                           Color. SPADNS.                                                                           
                          Manual           ...........  D1179-93B             4500F-C.............                  
                           Electrode.                                                                               
                          Automated        ...........  ....................  ....................  \11\380-75WE    
                           Electrode.                                                                               
                          Automated        ...........  ....................  4500F-E.............  \11\129-71W     
                           Alizarin.                                                                                
    Mercury.............  Manual, Cold        \2\245.1  D3223-91              3112B...............                  
                           Vapor.                                                                                   
                          Automated, Cold     \1\245.2                                                              
                           Vapor.                                                                                   
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
    Nickel..............  Inductively         \2\200.7  ....................  3120B...............                  
                           Coupled Plasma.                                                                          
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  ....................  3111B...............                  
                           Absorption;                                                                              
                           Direct.                                                                                  
                          Atomic           ...........  ....................  3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Nitrate.............  Ion                 \6\300.0  D4327-91              4110B...............  \8\B-1011       
                           Chromatography.                                                                          
                          Automated           \6\353.2  D3867-90A             4500-NO3-F..........                  
                           Cadmium                                                                                  
                           Reduction.                                                                               
                          Ion Selective    ...........  ....................  4500-NO3-D..........  \7\601          
                           Electrode.                                                                               
                          Manual Cadmium   ...........  D3867-90B             4500-NO3-E..........                  
                           Reduction.                                                                               
    Nitrite.............  Ion                 \6\300.0  D4327-91              4110B...............  \8\B-1011       
                           Chromatography.                                                                          
                          Automated           \6\353.2  D3867-90A             4500-NO3-F..........                  
                           Cadmium                                                                                  
                           Reduction.                                                                               
                          Manual Cadmium   ...........  D3867-90B             4500-NO3-E..........                  
                           Reduction.                                                                               
                          Spectrophotomet  ...........  ....................  4500-NO2-B..........                  
                           ric.                                                                                     
    Selenium............  Hydride-Atomic   ...........  D3859-93A             3114B...............                  
                           Absorption.                                                                              
                          ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
                          Atomic           ...........  D3859-93B             3113B...............                  
                           Absorption;                                                                              
                           Furnace.                                                                                 
    Thallium............  ICP-Mass            \2\200.8                                                              
                           Spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           Absorption;                                                                              
                           Platform.                                                                                
    Lead................  Atomic           ...........  D3559-90D             3113B...............                  
                           absorption;                                                                              
                           furnace.                                                                                 
                          ICP-Mass            \2\200.8                                                              
                           spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           absorption;                                                                              
                           platform.                                                                                
    Copper..............  Atomic           ...........  D1688-90C             3113B...............                  
                           absorption;                                                                              
                           furnace.                                                                                 
                          Atomic           ...........  D1688-90A             3111B...............                  
                           absorption;                                                                              
                           direct                                                                                   
                           aspiration.                                                                              
                          ICP............     \2\200.7  ....................  3120B...............                  
                          ICP-Mass            \2\200.8                                                              
                           spectrometry.                                                                            
                          Atomic              \2\200.9                                                              
                           absorption;                                                                              
                           platform.                                                                                
    pH..................  Electrometric..     \1\150.1  D1293-84              4500-H+-B...........                  
                          ...............     \1\150.2                                                              
    Conductivity........  Conductance....  ...........  D1125-91A             2510B...............                  
    Calcium.............  EDTA             ...........  D511-93A              3500-Ca-D...........                  
                           titrimetric.                                                                             
                          Atomic           ...........  D511-93B              3111B...............                  
                           absorption;                                                                              
                           direct                                                                                   
                           aspiration.                                                                              
                          Inductively-        \2\200.7  ....................  3120B...............                  
                           coupled plasma.                                                                          
    Alkalinity..........  Titrimetric....  ...........  D1067-92B             2320B...............                  
                          Electrometric    ...........  ....................  ....................  \5\I-1030-85    
                           titration.                                                                               
    Orthophosphate\12\..  Colorimetric,       \6\365.1  ....................  4500-P-F............                  
                           automated,                                                                               
                           ascorbic acid.                                                                           
                          Colorimetric,    ...........  D515-88A              4500-P-E............                  
                           ascorbic acid,                                                                           
                           single reagent.                                                                          
                          Colorimetric,    ...........  ....................  ....................  \5\I-1601-85    
                           phosphomolybda                                                                           
                           te;.                                                                                     
                          automated-       ...........  ....................  ....................  \5\I-2601-90    
                           segmented                                                                                
                           flow;.                                                                                   
                          automated        ...........  ....................  ....................  \5\I-2598-85    
                           discrete.                                                                                
                          Ion                 \6\300.0  D4327-91              4110................                  
                           Chromatography.                                                                          
    Silica..............  Colorimetric,    ...........  ....................  ....................  \5\I-1700-85    
                           molybdate                                                                                
                           blue;.                                                                                   
                          automated-       ...........  ....................  ....................  \5\I-2700-85    
                           segmented flow.                                                                          
                          Colorimetric...  ...........  D859-88                                                     
                          Molybdosilicate  ...........  ....................  4500-Si-D...........                  
                          Heteropoly blue  ...........  ....................  4500-Si-E...........                  
                          Automated        ...........  ....................  4500-Si-F...........                  
                           method for                                                                               
                           molybdate-                                                                               
                           reactive                                                                                 
                           silica.                                                                                  
                          Inductively-        \2\200.7  ....................  3120B...............                  
                           coupled plasma.                                                                          
    Temperature.........  Thermometric...  ...........  ....................  2550B...............                  
    Sodium..............  Inductively-        \2\200.7                                                              
                           coupled plasma.                                                                          
                          Atomic           ...........  ....................  3111B...............                  
                           Absorption;                                                                              
                           direct                                                                                   
                           aspiration.                                                                              
    ----------------------------------------------------------------------------------------------------------------
    Footnotes:                                                                                                      
    \1\Methods 150.1, 150.2 and 245.2 are available from US EPA, EMSL, Cincinnati, OH 45268. The identical methods  
      were formerly in ``Methods for Chemical Analysis of Water and Wastes'', EPA-600/4-79-020, March 1983, which is
      available at NTIS, PB84-128677.                                                                               
    \2\``Methods for the Determination of Metals in Environmental Samples--Supplement I'', EPA-600/R-94-111, May    
      1994. Available at NTIS, PB 94-184942.                                                                        
    \3\The procedures shall be done in accordance with the Annual Book of ASTM Standards, 1994, Vols. 11.01 and     
      11.02, American Society for Testing and Materials. This incorporation by reference was approved by the        
      Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained 
      from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. Copies may be  
      inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the    
      Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                   
    \4\The procedures shall be done in accordance with the 18th edition of Standard Methods for the Examination of  
      Water and Wastewater, 1992, American Public Health Association. This incorporation by reference was approved  
      by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be   
      obtained from the American Public Health Association, 1015 Fifteenth Street NW, Washington, DC 20005. Copies  
      may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
      the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                               
    \5\Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425,       
      Denver, CO 80225-0425.                                                                                        
    \6\``Methods for the Determination of Inorganic Substances in Environmental Samples'', EPA-600/R-93-100, August 
      1993. Available at NTIS, PB94-121811.                                                                         
    \7\The procedure shall be done in accordance with the Technical Bulletin 601 ``Standard Method of Test for      
      Nitrate in Drinking Water'', July 1994, PN 221890-001, Analytical Technology, Inc. This incorporation by      
      reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR   
      Part 51. Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA 02129. Copies may be inspected at 
      EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the Federal         
      Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                           
    \8\Method B-1011, ``Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion    
      Chromatography'', Millipore Corporation, Waters Chromatography Division, 34 Maple Street, Milford, MA 01757.  
    \9\Method 100.1, ``Analytical Method For Determination of Asbestos Fibers in Water'', EPA-600/4-83-043, EPA,    
      September 1983. Available at NTIS, PB83-260471.                                                               
    \10\Method 100.2, ``Determination Of Asbestos Structure Over 10-m In Length In Drinking Water'', EPA-  
      600/R-94-134, June 1994. Available at NTIS, PB94-201902.                                                      
    \11\The procedures shall be done in accordance with the Industrial Method No. 129-71W, ``Fluoride in Water and  
      Wastewater'', December 1972, and Method No. 380-75WE, ``Fluoride in Water and Wastewater'', February 1976,    
      Technicon Industrial Systems. This incorporation by reference was approved by the Director of the Federal     
      Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from the Technicon      
      Industrial Systems, Tarrytown, NY 10591. Copies may be inspected at EPA's Drinking Water Docket, 401 M Street,
      SW., Washington, DC 20460; or at the Office of Federal Register, 800 Capitol Street, NW., Suite 700,          
      Washington, DC.                                                                                               
    \12\Unfiltered, no digestion or hydrolysis.                                                                     
    
    * * * * *
        (q) [Reserved]
        5. Section 141.24 is amended by removing and reserving paragraphs 
    (f)(16), and (h)(12), adding paragraphs (e), reviewing paragraph 
    (h)(13), introductory text, and paragraph (h)(13)(i) to read as 
    follows:
    
    
    Sec. 141.24  Organic chemicals other than total trihalomethanes, 
    sampling and analytical requirements.
    
    * * * * *
        (e) Analyses for the contaminants in this section shall be 
    conducted using the following EPA methods or their equivalent as 
    approved by EPA. Methods 502.2, 505, 507, 508, 508A, 515.1 and 531.1 
    are in Methods for the Determination of Organic Compounds in Drinking 
    Water, EPA-600/4-88-039, December 1988, Revised, July 1991. Methods 
    506, 547, 550, 550.1 and 551 are in Methods for the Determination of 
    Organic Compounds in Drinking Water--Supplement I, EPA-600-4-90-020, 
    July 1990. Methods 515.2, 524.2, 548.1, 549.1, 552.1 and 555 are in 
    Methods for the Determination of Organic Compounds in Drinking Water--
    Supplement II, EPA-600/R-92-129, August 1992. Method 1613 is titled 
    ``Tetra-through Octa-Chlorinated Dioxins and Furans by Isotope-Dilution 
    HRGC/HRMS'', EPA-821-B-94-005, October 1994. These documents are 
    available from the National Technical Information Service, NTIS PB91-
    231480, PB91-146027, PB92-207703 and PB95-104774, U.S. Department of 
    Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll-
    free number is 800-553-6847. Method 6651 shall be followed in 
    accordance with the 18th edition of Standard Methods for the 
    Examination of Water and Wastewater, 1992, American Public Health 
    Association. This incorporation by reference was approved by the 
    Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 
    1 CFR Part 51. Copies may be obtained from the American Public Health 
    Association, 1015 Fifteenth Street NW., Washington, DC 20005. Copies 
    may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., 
    Washington, DC 20460; or at the Office of the Federal Register, 800 
    North Capitol Street, NW., Suite 700, Washington, DC. Method 6610 shall 
    be followed in accordance with the Supplement to the 18th edition of 
    Standard Methods for the Examination of Water and Wastewater, 1994, 
    American Public Health Association. This incorporation by reference was 
    approved by the Director of the Federal Register in accordance with 5 
    U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from the 
    American Public Health Association, 1015 Fifteenth Street NW., 
    Washington, DC 20005. Copies may be inspected at EPA's Drinking Water 
    Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
    the Federal Register, 800 North Capitol Street, NW., Suite 700, 
    Washington, DC. Other analytical test procedures are contained in 
    Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 
    1994, NTIS PB95-104766. This document also contains approved analytical 
    methods which remain available for compliance monitoring until July 1, 
    1996. These methods will not be available for use after July 1, 1996. 
    EPA Methods 504.1, 508.1 and 525.2 are available from US EPA EMSL, 
    Cincinnati, OH 45268. The phone number is 513-569-7586.
    
    ------------------------------------------------------------------------
                Contaminant                             Method              
    ------------------------------------------------------------------------
    Benzene............................  502.2, 524.2.                      
    Carbon tetrachloride...............  502.2, 524.2, 551.                 
    Chlorobenzene......................  502.2, 524.2.                      
    1,2-Dichlorobenzene................  502.2, 524.2.                      
    1,4-Dichlorobenzene................  502.2, 524.2.                      
    1,2-Dichloroethane.................  502.2, 524.2.                      
    cis-Dichloroethylene...............  502.2, 524.2.                      
    trans-Dichloroethylene.............  502.2, 524.2.                      
    Dichloromethane....................  502.2, 524.2.                      
    1,2-Dichloropropane................  502.2, 524.2.                      
    Ethylbenzene.......................  502.2, 524.2.                      
    Styrene............................  502.2, 524.2.                      
    Tetrachloroethylene................  502.2, 524.2, 551.                 
    1,1,1-Trichloroethane..............  502.2, 524.2, 551.                 
    Trichloroethylene..................  502.2, 524.2, 551.                 
    Toluene............................  502.2, 524.2.                      
    1,2,4-Trichlorobenzene.............  502.2, 524.2.                      
    1,1-Dichloroethylene...............  502.2, 524.2.                      
    1,1,2-Trichloroethane..............  502.2, 524.2.                      
    Vinyl chloride.....................  502.2, 524.2.                      
    Xylenes (total)....................  502.2, 524.2.                      
    2,3,7,8-TCDD (dioxin)..............  1613.                              
    2,4-D..............................  515.2, 555, 515.1.                 
    2,4,5-TP (Silvex)..................  515.2, 555, 515.1.                 
    Alachlor...........................  505\1\, 507, 525.2, 508.1.         
    Atrazine...........................  505\1\, 507, 525.2, 508.1.         
    Benzo(a)pyrene.....................  525.2, 550, 550.1.                 
    Carbofuran.........................  531.1, 6610.                       
    Chlordane..........................  505, 508, 525.2, 508.1.            
    Dalapon............................  552.1, 515.1.                      
    Di(2-ethylhexyl) adipate...........  506, 525.2.                        
    Di(2-ethylhexyl) phthalate.........  506, 525.2.                        
    Dibromochloropropane (DBCP)........  504.1, 551.                        
    Dinoseb............................  515.2, 555, 515.1.                 
    Diquat.............................  549.1.                             
    Endothall..........................  548.1.                             
    Endrin.............................  505, 508, 525.2, 508.1.            
    Ethylene dibromide (EDB)...........  504.1, 551.                        
    Glyphosate.........................  547, 6651.                         
    Heptachlor.........................  505, 508, 525.2, 508.1.            
    Heptachlor Epoxide.................  505, 508, 525.2, 508.1.            
    Hexachlorobenzene..................  505, 508, 525.2, 508.1.            
    Hexachlorocyclopentadiene..........  505, 525.2, 508, 508.1.            
    Lindane............................  505, 508, 525.2, 508.1.            
    Methoxychlor.......................  505, 508, 525.2, 508.1.            
    Oxamyl.............................  531.1, 6610.                       
    PCBs\2\ (as decachlorobiphenyl)....  508A.                              
      (as Aroclors)....................  505, 508.                          
    Pentachlorophenol..................  515.2, 525.2, 555, 515.1.          
    Picloram...........................  515.2, 555, 515.1.                 
    Simazine...........................  505\1\, 507, 525.2, 508.1.         
    Toxaphene..........................  505, 508, 525.2.                   
    Total Trihalomethanes..............  502.2, 524.2, 551.                 
    ------------------------------------------------------------------------
    \1\A nitrogen-phosphorous detector should be substituted for the        
      electron capture detector in Method 505 (or another approved method   
      should be used) to determine alachlor, atrazine and simazine, if lower
      detection limits are required.                                        
    \2\PCBs are qualitatively identified as Aroclors and measured for       
      compliance purposes as decachlorobiphenyl.                            
    
    * * * * *
        (h) * * *
        (12) (Reserved)
        (13) Analysis for PCBs shall be conducted as follows using the 
    methods in paragraph (e) of this section:
        (i) Each system which monitors for PCBs shall analyze each sample 
    using either Method 505 or Method 508.
    * * * * *
        6. Section 141.30 is amended by revising paragraph (e) and by 
    removing removing Appendix A, Appendix B, and Appendix C to read as 
    follows:
    
    
    Sec. 141.30  Total trihalomethane sampling, analytical and other 
    requirements.
    
    * * * * *
        (e) Sampling and analyses made pursuant to this section shall be 
    conducted by the total trihalomethane methods as directed in 
    Sec. 141.24(e), and in Technical Notes on Drinking Water Methods, EPA-
    600/R-94-173, October 1994, which is available at NTIS, PB95-104766.
    * * * * *
        7. Section 141.40 is amended by revising paragraphs (g), (n)(11), 
    and (n)(12) to read as follows:
    
    
    Sec. 141.40  Special monitoring for inorganic and organic chemicals.
    
    * * * * *
        (g) Analysis for the unregulated contaminants listed under 
    paragraphs (e) and (j) of this section shall be conducted using EPA 
    Methods 502.2 or 524.2, or their equivalent as determined by EPA, 
    except analysis for bromodichloromethane, bromoform, 
    chlorodibromomethane and chloroform under paragraph (e) of this section 
    also may be conducted by EPA Method 551, and analysis for 1,2,3-
    trichloropropane also may be conducted by EPA Method 504.1. A source 
    for the EPA methods is referenced at Sec. 141.24(e).
    * * * * *
        (n) * * *
        (11) Systems shall monitor for the unregulated organic contaminants 
    listed below, using the method(s) identified below and using the 
    analytical test procedures contained in Technical Notes on Drinking 
    Water Methods, EPA-600/R-94-173, October 1994, which is available at 
    NTIS, PB95-104766. Method 6610 shall be followed in accordance with the 
    Standard Methods for the Examination of Water and Wastewater 18th 
    Edition Supplement, 1994, American Public Health Association. This 
    incorporation by reference was approved by the Director of the Federal 
    Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies 
    may be obtained from the American Public Health Association, 1015 
    Fifteenth Street NW, Washington, DC 20005. Copies may be inspected at 
    EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; 
    or at the Office of the Federal Register, 800 North Capitol Street, 
    NW., Suite 700, Washington, DC. A source for EPA methods 505, 507, 508, 
    508.1, 515.2, 525.2 and 531.1 is referenced at Sec. 141.24(e).
    
    ------------------------------------------------------------------------
                Contaminants                            Method              
    ------------------------------------------------------------------------
    aldicarb...........................  531.1, 6610.                       
    aldicarb sulfone...................  531.1, 6610.                       
    aldicarb sulfoxide.................  531.1, 6610.                       
    aldrin.............................  505, 508, 525.2, 508.1.            
    butachlor..........................  507, 525.2.                        
    carbaryl...........................  531.1, 6610.                       
    dicamba............................  515.2, 555, 515.1.                 
    dieldrin...........................  505, 508, 525.2, 508.1.            
    3-hydroxycarbofuran................  531.1, 6610.                       
    methomyl...........................  531.1, 6610.                       
    metolachlor........................  507, 525.2, 508.1.                 
    metribuzin.........................  507, 525.2, 508.1.                 
    propachlor.........................  508, 525.2, 508.1.                 
    ------------------------------------------------------------------------
    
        (12) Systems shall monitor for sulfate, an unregulated inorganic 
    contaminant, by using the methods listed at Sec. 143.4(b).
    * * * * *
        8. Section 141.41 is amended by revising paragraph (d) to read as 
    follows:
    
    
    Sec. 141.41  Special monitoring for sodium.
    
    * * * * *
        (d) Analyses for sodium shall be conducted as directed in 
    Sec. 141.23(k)(1).
        9. Section 141.42 is amended by removing and reserving paragraphs 
    (a) through (c).
        10. Section 141.74 is amended by revising paragraphs (a)(1) and 
    (a)(2), and removing paragraphs (a)(3) through (a)(7) to read as 
    follows:
    
    
    Sec. 141.74  Analytical and monitoring requirements.
    
        (a) * * *
        (1) Public water systems must conduct analysis of pH in accordance 
    with one of the methods listed at Sec. 141.23(k)(1). Public water 
    systems must conduct analyses of total coliforms, fecal coliforms, 
    heterotrophic bacteria, turbidity, and temperature in accordance with 
    one of the following analytical methods and by using analytical test 
    procedures contained in Technical Notes on Drinking Water Methods, EPA-
    600/R-94-173, October 1994, which is available at NTIS PB95-104766.
    
    ------------------------------------------------------------------------
            Organism                 Methodology             Citation\1\    
    ------------------------------------------------------------------------
    Total Coliforms.........  Total Coliform            9221A, B, C         
                               Fermentation Technique/                      
                               3,4,5/.                                      
                              Total Coliform Membrane   9222A, B, C         
                               Filter Technique.                            
                              ONPG-MUG Test\6\........  9223                
    Fecal Coliforms.........  Fecal Coliform MPN        9221E               
                               Procedure\7\.                                
                              Fecal Coliforms Membrane  9222D               
                               Filter Procedure.                            
    Heterotrophic             Pour Plate Method.......  9215B               
     bacteria\2\.                                                           
    Turbidity...............  Nephelometric Method....  2130B               
                              Nephelometric Method....  180.1\8\            
                              Great Lakes Instruments.  Method 2\9\         
    Temperature.............  ........................  2550                
    ------------------------------------------------------------------------
    Footnotes:                                                              
    \1\Except where noted, all methods refer to the 18th edition of Standard
      Methods for the Examination of Water and Wastewater, 1992, American   
      Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 
      20005.                                                                
    \2\The time from sample collection to initiation of analysis may not    
      exceed 8 hours.                                                       
    \3\Lactose broth, as commercially available, may be used in lieu of     
      lauryl tryptose broth, if the system conducts at least 25 parallel    
      tests between this medium and lauryl tryptose broth using the water   
      normally tested, and this comparison demonstrates that the false-     
      positive rate for total coliforms, using lactose broth, is less than  
      10 percent.                                                           
    \4\Media should cover inverted tubes at least one-half to two-thirds    
      after the sample is added.                                            
    \5\No requirement exists to run the completed phase on 10 percent of all
      total coliform-positive confirmed tubes.                              
    \6\The ONPG-MUG Test is also known as the Autoanalysis Colilert System. 
    \7\A-1 Broth may be held up to three months in a tightly closed screwcap
      tube at 4 deg.C.                                                      
    \8\``Methods for the Determination of Inorganic Substances in           
      Environmental Samples'', EPA-600/R-93-100, August 1993. Available at  
      NTIS, PB94-121811.                                                    
    \9\GLI Method 2, ``Turbidity'', November 2, 1992, Great Lakes           
      Instruments, Inc., 8855 North 55th Street, Milwaukee, Wisconsin 53223.
    
        (2) Public water systems must measure residual disinfectant 
    concentrations with one of the analytical methods in the following 
    table. The methods are contained in the 18th edition of Standard 
    Methods for the Examination of Water and Wastewater, 1992. Other 
    analytical test procedures are contained in Technical Notes on Drinking 
    Water Methods, EPA-600/R-94-173, October 1994, which is available at 
    NTIS PB95-104766. If approved by the State, residual disinfectant 
    concentrations for free chlorine and combined chlorine also may be 
    measured by using DPD colorimetric test kits. Free and total chlorine 
    residuals may be measured continuously by adapting a specified chlorine 
    residual method for use with a continuous monitoring instrument 
    provided the chemistry, accuracy, and precision remain same. 
    Instruments used for continuous monitoring must be calibrated with a 
    grab sample measurement at least every five days, or with a protocol 
    approved by the State.
    
    ------------------------------------------------------------------------
            Residual                 Methodology               Methods      
    ------------------------------------------------------------------------
    Free Chlorine...........  Amperometric Titration..  4500-Cl D           
                              DPD Ferrous Titrimetric.  4500-Cl F           
                              DPD Colorimetric........  4500-Cl G           
                              Syringaldazine (FACTS)..  4500-Cl H           
    Total Chlorine..........  Amperometric Titration..  4500-Cl D           
                              Amperometric Titration    4500-Cl E           
                               (low level measurement).                     
                              DPD Ferrous Titrimetric.  4500-Cl F           
                              DPD Colorimetric........  4500-Cl G           
                              Iodometric Electrode....  4500-Cl I           
    Chlorine Dioxide........  Amperometric Titration..  4500-ClO2 C         
                              DPD Method..............  4500-ClO2 D         
                              Amperometric Titration..  4500-ClO2 E         
    Ozone...................  Indigo Method...........  4500-O3 B           
    ------------------------------------------------------------------------
    
    * * * * *
        11. Section 141.89 is amended by revising paragraph (a) 
    introductory text; removing the table in paragraph (a); and by removing 
    and reserving paragraph (b) to read as follows:
    
    
    Sec. 141.89  Analytical methods.
    
        (a) Analyses for lead, copper, pH, conductivity, calcium, 
    alkalinity, orthophosphate, silica, and temperature shall be conducted 
    with the methods in Sec. 141.23(k)(1).
    * * * * *
    
    PART 143--NATIONAL SECONDARY DRINKING WATER REGULATIONS
    
        1. The authority citation for part 143 continues to read as 
    follows:
    
        Authority: 42 U.S.C. 300f, 300g-1, 300g-2 300g-3, 300g-4, 300g-
    5, 300g-6, 300j-4, 300j-9.
    
        2. Section 143.4 is amended by revising paragraph (b) to read as 
    follows:
    
    
    Sec. 143.4  Monitoring.
    
    * * * * *
        (b) Measurement of pH, copper and fluoride to determine compliance 
    under Sec. 143.3 may be conducted with one of the methods in 
    Sec. 141.23(k)(1). Analyses of aluminum, chloride, foaming agents, 
    iron, manganese, odor, silver, sulfate, total dissolved solids (TDS) 
    and zinc to determine compliance under Sec. 143.3 may be conducted with 
    the methods in the following Table. Criteria for analyzing aluminum, 
    copper, iron, manganese, silver and zinc samples with digestion or 
    directly without digestion, and other analytical test procedures are 
    contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-
    173, October 1994, which is available at NTIS PB95-104766.
    
    ----------------------------------------------------------------------------------------------------------------
                Contaminant                  EPA             ASTM\3\                  SM4                 Other     
    ----------------------------------------------------------------------------------------------------------------
    Aluminum...........................     \2\200.7  ....................  3120B.................                  
                                            \2\200.8  ....................  3113B.................                  
                                            \2\200.9  ....................  3111D.................                  
    Chloride...........................     \1\300.0  D4327-91............  4110..................                  
                                                                            4500-Cl--D............                  
    Color..............................  ...........  ....................  2120B.................                  
    Foaming Agents.....................  ...........  ....................  5540C.................                  
    Iron...............................     \2\200.7  ....................  3120B.................                  
                                            \2\200.9  ....................  3111B.................                  
                                                                            3113B.................                  
    Manganese..........................     \2\200.7  ....................  3120B.................                  
                                            \2\200.8  ....................  3111B.................                  
                                            \2\200.9  ....................  3113B.................                  
    Odor...............................  ...........  ....................  2150B.................                  
    Silver.............................     \2\200.7  ....................  3120B.................  I-3720-85\5\    
                                            \2\200.8  ....................  3111B.................                  
                                            \2\200.9  ....................  3113B.................                  
    Sulfate............................     \1\300.0  D4327-91............  4110..................                  
                                            \1\375.2  ....................  4500-SO4-F............                  
                                                                            4500-SO4-C,D..........                  
    TDS................................  ...........  ....................  2540C.................                  
    Zinc...............................     \2\200.7  ....................  3120B.................                  
                                            \2\200.8  ....................  3111B ................                  
    ----------------------------------------------------------------------------------------------------------------
    Footnotes:                                                                                                      
    \1\``Methods for the Determination of Inorganic Substances in Environmental Samples'', EPA-600/R-93-100, August 
      1993. Available at NTIS, PB94-121811.                                                                         
    \2\``Methods for the Determination of Metals in Environmental Samples--Supplement I'', EPA-600/R-94-111, May    
      1994. Available at NTIS, PB94-184942.                                                                         
    \3\The procedures shall be done in accordance with the Annual Book of ASTM Standards, 1994, Vols. 11.01 and     
      11.02, American Society for Testing and Materials. This incorporation by reference was approved by the        
      Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained 
      from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. Copies may be  
      inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of the    
      Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                                   
    \4\The procedures shall be done in accordance with the 18th edition of Standard Methods for the Examination of  
      Water and Wastewater, 1992, American Public Health Association. This incorporation by reference was approved  
      by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be   
      obtained from the American Public Health Association, 1015 Fifteenth Street NW., Washington, DC 20005. Copies 
      may be inspected at EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or at the Office of 
      the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.                               
    \5\Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425,       
      Denver, CO 80225-0425.                                                                                        
    
    [FR Doc. 94-29692 Filed 12-2-94; 8:45 am]
    BILLING CODE 6560-50-P
    
    
    

Document Information

Effective Date:
1/4/1995
Published:
12/05/1994
Department:
Environmental Protection Agency
Entry Type:
Uncategorized Document
Action:
Final rule.
Document Number:
94-29692
Dates:
This final rule is effective on January 4, 1995. The incorporation of the publications listed in this document are approved by the Director of the Federal Register as of January 4, 1995.
Pages:
0-0 (1 pages)
Docket Numbers:
Federal Register: December 5, 1994, WH-FRL-5116-4
RINs:
2040-AC12
CFR: (14)
40 CFR 141.74(a)(1)
1 CFR 141.24(e)
1 CFR 141.23(k)(1)
1 CFR 141.23(k)(1)
1 CFR 141.30
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