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Title 40Chapter ISubchapter DPart 141 → Subpart C


Title 40: Protection of Environment
PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS


Subpart C—Monitoring and Analytical Requirements


Contents
§141.21   Coliform sampling.
§141.22   Turbidity sampling and analytical requirements.
§141.23   Inorganic chemical sampling and analytical requirements.
§141.24   Organic chemicals, sampling and analytical requirements.
§141.25   Analytical methods for radioactivity.
§141.26   Monitoring frequency and compliance requirements for radionuclides in community water systems.
§141.27   Alternate analytical techniques.
§141.28   Certified laboratories.
§141.29   Monitoring of consecutive public water systems.
Appendix A to Subpart C of Part 141—Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act

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§141.21   Coliform sampling.

(a) Routine monitoring. (1) Public water systems must collect total coliform samples at sites which are representative of water throughout the distribution system according to a written sample siting plan. These plans are subject to State review and revision.

(2) The monitoring frequency for total coliforms for community water systems is based on the population served by the system, as follows:

Total Coliform Monitoring Frequency for Community Water Systems

Population servedMinimum number of samples per month
25 to 1,00011
1,001 to 2,5002
2,501 to 3,3003
3,301 to 4,1004
4,101 to 4,9005
4,901 to 5,8006
5,801 to 6,7007
6,701 to 7,6008
7,601 to 8,5009
8,501 to 12,90010
12,901 to 17,20015
17,201 to 21,50020
21,501 to 25,00025
25,001 to 33,00030
33,001 to 41,00040
41,001 to 50,00050
50,001 to 59,00060
59,001 to 70,00070
70,001 to 83,00080
83,001 to 96,00090
96,001 to 130,000100
130,001 to 220,000120
220,001 to 320,000150
320,001 to 450,000180
450,001 to 600,000210
600,001 to 780,000240
780,001 to 970,000270
970,001 to 1,230,000300
1,230,001 to 1,520,000330
1,520,001 to 1,850,000360
1,850,001 to 2,270,000390
2,270,001 to 3,020,000420
3,020,001 to 3,960,000450
3,960,001 or more480

1Includes public water systems which have at least 15 service connections, but serve fewer than 25 persons.

If a community water system serving 25 to 1,000 persons has no history of total coliform contamination in its current configuration and a sanitary survey conducted in the past five years shows that the system is supplied solely by a protected groundwater source and is free of sanitary defects, the State may reduce the monitoring frequency specified above, except that in no case may the State reduce the monitoring frequency to less than one sample per quarter. The State must approve the reduced monitoring frequency in writing.

(3) The monitoring frequency for total coliforms for non-community water systems is as follows:

(i) A non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in §141.2) and serving 1,000 persons or fewer must monitor each calendar quarter that the system provides water to the public, except that the State may reduce this monitoring frequency, in writing, if a sanitary survey shows that the system is free of sanitary defects. Beginning June 29, 1994, the State cannot reduce the monitoring frequency for a non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in §141.2) and serving 1,000 persons or fewer to less than once/year.

(ii) A non-community water system using only ground water (except ground water under the direct influence of surface water, as defined in §141.2) and serving more than 1,000 persons during any month must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section, except the State may reduce this monitoring frequency, in writing, for any month the system serves 1,000 persons or fewer. The State cannot reduce the monitoring frequency to less than once/year. For systems using ground water under the direct influence of surface water, paragraph (a)(3)(iv) of this section applies.

(iii) A non-community water system using surface water, in total or in part, must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section, regardless of the number of persons it serves.

(iv) A non-community water system using ground water under the direct influence of surface water, as defined in §141.2, must monitor at the same frequency as a like-sized community water system, as specified in paragraph (a)(2) of this section. The system must begin monitoring at this frequency beginning six months after the State determines that the ground water is under the direct influence of surface water.

(4) The public water system must collect samples at regular time intervals throughout the month, except that a system which uses only ground water (except ground water under the direct influence of surface water, as defined in §141.2), and serves 4,900 persons or fewer, may collect all required samples on a single day if they are taken from different sites.

(5) A public water system that uses surface water or ground water under the direct influence of surface water, as defined in §141.2, and does not practice filtration in compliance with Subpart H must collect at least one sample near the first service connection each day the turbidity level of the source water, measured as specified in §141.74(b)(2), exceeds 1 NTU. This sample must be analyzed for the presence of total coliforms. When one or more turbidity measurements in any day exceed 1 NTU, the system must collect this coliform sample within 24 hours of the first exceedance, unless the State determines that the system, for logistical reasons outside the system's control, cannot have the sample analyzed within 30 hours of collection. Sample results from this coliform monitoring must be included in determining compliance with the MCL for total coliforms in §141.63.

(6) Special purpose samples, such as those taken to determine whether disinfection practices are sufficient following pipe placement, replacement, or repair, shall not be used to determine compliance with the MCL for total coliforms in §141.63. Repeat samples taken pursuant to paragraph (b) of this section are not considered special purpose samples, and must be used to determine compliance with the MCL for total coliforms in §141.63.

(b) Repeat monitoring. (1) If a routine sample is total coliform-positive, the public water system must collect a set of repeat samples within 24 hours of being notified of the positive result. A system which collects more than one routine sample/month must collect no fewer than three repeat samples for each total coliform-positive sample found. A system which collects one routine sample/month or fewer must collect no fewer than four repeat samples for each total coliform-positive sample found. The State may extend the 24-hour limit on a case-by-case basis if the system has a logistical problem in collecting the repeat samples within 24 hours that is beyond its control. In the case of an extension, the State must specify how much time the system has to collect the repeat samples.

(2) The system must collect at least one repeat sample from the sampling tap where the original total coliform-positive sample was taken, and at least one repeat sample at a tap within five service connections upstream and at least one repeat sample at a tap within five service connections downstream of the original sampling site. If a total coliform-positive sample is at the end of the distribution system, or one away from the end of the distribution system, the State may waive the requirement to collect at least one repeat sample upstream or downstream of the original sampling site.

(3) The system must collect all repeat samples on the same day, except that the State may allow a system with a single service connection to collect the required set of repeat samples over a four-day period or to collect a larger volume repeat sample(s) in one or more sample containers of any size, as long as the total volume collected is at least 400 ml (300 ml for systems which collect more than one routine sample/month).

(4) If one or more repeat samples in the set is total coliform-positive, the public water system must collect an additional set of repeat samples in the manner specified in paragraphs (b) (1)-(3) of this section. The additional samples must be collected within 24 hours of being notified of the positive result, unless the State extends the limit as provided in paragraph (b)(1) of this section. The system must repeat this process until either total coliforms are not detected in one complete set of repeat samples or the system determines that the MCL for total coliforms in §141.63 has been exceeded and notifies the State.

(5) If a system collecting fewer than five routine samples/month has one or more total coliform-positive samples and the State does not invalidate the sample(s) under paragraph (c) of this section, it must collect at least five routine samples during the next month the system provides water to the public, except that the State may waive this requirement if the conditions of paragraph (b)(5) (i) or (ii) of this section are met. The State cannot waive the requirement for a system to collect repeat samples in paragraphs (b) (1)-(4) of this section.

(i) The State may waive the requirement to collect five routine samples the next month the system provides water to the public if the State, or an agent approved by the State, performs a site visit before the end of the next month the system provides water to the public. Although a sanitary survey need not be performed, the site visit must be sufficiently detailed to allow the State to determine whether additional monitoring and/or any corrective action is needed. The State cannot approve an employee of the system to perform this site visit, even if the employee is an agent approved by the State to perform sanitary surveys.

(ii) The State may waive the requirement to collect five routine samples the next month the system provides water to the public if the State has determined why the sample was total coliform-positive and establishes that the system has corrected the problem or will correct the problem before the end of the next month the system serves water to the public. In this case, the State must document this decision to waive the following month's additional monitoring requirement in writing, have it approved and signed by the supervisor of the State official who recommends such a decision, and make this document available to the EPA and public. The written documentation must describe the specific cause of the total coliform-positive sample and what action the system has taken and/or will take to correct this problem. The State cannot waive the requirement to collect five routine samples the next month the system provides water to the public solely on the grounds that all repeat samples are total coliform-negative. Under this paragraph, a system must still take at least one routine sample before the end of the next month it serves water to the public and use it to determine compliance with the MCL for total coliforms in §141.63, unless the State has determined that the system has corrected the contamination problem before the system took the set of repeat samples required in paragraphs (b) (1)-(4) of this section, and all repeat samples were total coliform-negative.

(6) After a system collects a routine sample and before it learns the results of the analysis of that sample, if it collects another routine sample(s) from within five adjacent service connections of the initial sample, and the initial sample, after analysis, is found to contain total coliforms, then the system may count the subsequent sample(s) as a repeat sample instead of as a routine sample.

(7) Results of all routine and repeat samples not invalidated by the State must be included in determining compliance with the MCL for total coliforms in §141.63.

(c) Invalidation of total coliform samples. A total coliform-positive sample invalidated under this paragraph (c) does not count towards meeting the minimum monitoring requirements of this section.

(1) The State may invalidate a total coliform-positive sample only if the conditions of paragraph (c)(1) (i), (ii), or (iii) of this section are met.

(i) The laboratory establishes that improper sample analysis caused the total coliform-positive result.

(ii) The State, on the basis of the results of repeat samples collected as required by paragraphs (b) (1) through (4) of this section, determines that the total coliform-positive sample resulted from a domestic or other non-distribution system plumbing problem. The State cannot invalidate a sample on the basis of repeat sample results unless all repeat sample(s) collected at the same tap as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected within five service connections of the original tap are total coliform-negative (e.g., a State cannot invalidate a total coliform-positive sample on the basis of repeat samples if all the repeat samples are total coliform-negative, or if the public water system has only one service connection).

(iii) The State has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition which does not reflect water quality in the distribution system. In this case, the system must still collect all repeat samples required under paragraphs (b) (1)-(4) of this section, and use them to determine compliance with the MCL for total coliforms in §141.63. To invalidate a total coliform-positive sample under this paragraph, the decision with the rationale for the decision must be documented in writing, and approved and signed by the supervisor of the State official who recommended the decision. The State must make this document available to EPA and the public. The written documentation must state the specific cause of the total coliform-positive sample, and what action the system has taken, or will take, to correct this problem. The State may not invalidate a total coliform-positive sample solely on the grounds that all repeat samples are total coliform-negative.

(2) A laboratory must invalidate a total coliform sample (unless total coliforms are detected) if the sample produces a turbid culture in the absence of gas production using an analytical method where gas formation is examined (e.g., the Multiple-Tube Fermentation Technique), produces a turbid culture in the absence of an acid reaction in the Presence-Absence (P-A) Coliform Test, or exhibits confluent growth or produces colonies too numerous to count with an analytical method using a membrane filter (e.g., Membrane Filter Technique). If a laboratory invalidates a sample because of such interference, the system must collect another sample from the same location as the original sample within 24 hours of being notified of the interference problem, and have it analyzed for the presence of total coliforms. The system must continue to re-sample within 24 hours and have the samples analyzed until it obtains a valid result. The State may waive the 24-hour time limit on a case-by-case basis.

(d) Sanitary surveys. (1)(i) Public water systems which do not collect five or more routine samples/month must undergo an initial sanitary survey by June 29, 1994, for community public water systems and June 29, 1999, for non-community water systems. Thereafter, systems must undergo another sanitary survey every five years, except that non-community water systems using only protected and disinfected ground water, as defined by the State, must undergo subsequent sanitary surveys at least every ten years after the initial sanitary survey. The State must review the results of each sanitary survey to determine whether the existing monitoring frequency is adequate and what additional measures, if any, the system needs to undertake to improve drinking water quality.

(ii) In conducting a sanitary survey of a system using ground water in a State having an EPA-approved wellhead protection program under section 1428 of the Safe Drinking Water Act, information on sources of contamination within the delineated wellhead protection area that was collected in the course of developing and implementing the program should be considered instead of collecting new information, if the information was collected since the last time the system was subject to a sanitary survey.

(2) Sanitary surveys must be performed by the State or an agent approved by the State. The system is responsible for ensuring the survey takes place.

(3) Sanitary surveys conducted by the State under the provisions of §142.16(o)(2) of this chapter may be used to meet the sanitary survey requirements of this section.

(e) Fecal coliforms/Escherichia coli (E. coli) testing. (1) If any routine or repeat sample is total coliform-positive, the system must analyze that total coliform-positive culture medium to determine if fecal coliforms are present, except that the system may test for E. coli in lieu of fecal coliforms. If fecal coliforms or E. coli are present, the system must notify the State by the end of the day when the system is notified of the test result, unless the system is notified of the result after the State office is closed, in which case the system must notify the State before the end of the next business day.

(2) The State has the discretion to allow a public water system, on a case-by-case basis, to forgo fecal coliform or E. coli testing on a total coliform-positive sample if that system assumes that the total coliform-positive sample is fecal coliform-positive or E. coli-positive. Accordingly, the system must notify the State as specified in paragraph (e)(1) of this section and the provisions of §141.63(b) apply.

(f) Analytical methodology. (1) The standard sample volume required for total coliform analysis, regardless of analytical method used, is 100 ml.

(2) Public water systems need only determine the presence or absence of total coliforms; a determination of total coliform density is not required.

(3) Public water systems must conduct total coliform analyses in accordance with one of the analytical methods in the following table or one of the alternative methods listed in appendix A to subpart C of this part.

OrganismMethodology12Citation1
Total Coliforms2Total Coliform Fermentation Technique3 4 59221A, B.
   Total Coliform Membrane Filter Technique69222A, B, C.
   Presence-Absence (P-A) Coliform Test5 79221D.
   ONPG-MUG Test89223.
   Colisure Test.9
   E*Colite® Test.10
   m-ColiBlue24® Test.11
   Readycult® Coliforms 100 Presence/Absence Test.13
   Membrane Filter Technique using Chromocult® Coliform Agar.14
   Colitag® Test.15

The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents listed in footnotes 1, 6, 8, 9, 10 , 11, 13, 14 and 15 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html.

1Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), or 20th edition (1998). American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005. The cited methods published in any of these three editions may be used. In addition, the following online versions may also be used: 9221 A, B, D-99, 9222 A, B, C-97, and 9223 B-97. Standard Methods Online are available at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only Online versions that may be used.

2The time from sample collection to initiation of analysis may not exceed 30 hours. Systems are encouraged but not required to hold samples below 10 deg. C during transit.

3Lactose 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 and false-negative rate for total coliform, using lactose broth, is less than 10 percent.

4If 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.

5No requirement exists to run the completed phase on 10 percent of all total coliform-positive confirmed tubes.

6MI agar also may be used. Preparation and use of MI agar is set forth in the article, “New medium for the simultaneous detection of total coliform and Escherichia coli in water” by Brenner, K.P., et. al., 1993, Appl. Environ. Microbiol. 59:3534-3544. Also available from the Office of Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460, EPA/600/J-99/225. Verification of colonies is not required.

7Six-times formulation strength may be used if the medium is filter-sterilized rather than autoclaved.

8The ONPG-MUG Test is also known as the Autoanalysis Collect System.

9A description of the Colisure Test, Feb 28, 1994, may be obtained from IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092. The Colisure Test may be read after an incubation time of 24 hours.

10A description of the E*Colite® Test, “Presence/Absence for Coliforms and E. Coli in Water,” Dec 21, 1997, is available from Charm Sciences, Inc., 36 Franklin Street, Malden, MA 02148-4120.

11A description of the m-ColiBlue24® Test, Aug 17, 1999, is available from the Hach Company, 100 Dayton Avenue, Ames, IA 50010.

12EPA strongly recommends that laboratories evaluate the false-positive and negative rates for the method(s) they use for monitoring total coliforms. EPA also encourages laboratories to establish false-positive and false-negative rates within their own laboratory and sample matrix (drinking water or source water) with the intent that if the method they choose has an unacceptable false-positive or negative rate, another method can be used. The Agency suggests that laboratories perform these studies on a minimum of 5% of all total coliform-positive samples, except for those methods where verification/confirmation is already required, e.g., the M-Endo and LES Endo Membrane Filter Tests, Standard Total Coliform Fermentation Technique, and Presence-Absence Coliform Test. Methods for establishing false-positive and negative-rates may be based on lactose fermentation, the rapid test for β-galactosidase and cytochrome oxidase, multi-test identification systems, or equivalent confirmation tests. False-positive and false-negative information is often available in published studies and/or from the manufacturer(s).

13The Readycult® Coliforms 100 Presence/Absence Test is described in the document, “Readycult® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichla coli in Finished Waters”, November 2000, Version 1.0, available from EM Science (an affiliate of Merck KGgA, Darmstadt Germany), 480 S. Democrat Road, Gibbstown, NJ 08027-1297. Telephone number is (800) 222-0342, e-mail address is: adellenbusch@emscience.com.

14Membrane Filter Technique using Chromocult® Coliform Agar is described in the document, “Chromocult® Coliform Agar Presence/Absence Membrane Filter Test Method for Detection and Identification of Coliform Bacteria and Escherichla coli in Finished Waters”, November 2000, Version 1.0, available from EM Science (an affiliate of Merck KGgA, Darmstadt Germany), 480 S. Democrat Road, Gibbstown, NJ 08027-1297. Telephone number is (800) 222-0342, e-mail address is: adellenbusch@emscience.com.

15Colitag® product for the determination of the presence/absence of total coliforms and E. coli is described in “Colitag® Product as a Test for Detection and Identification of Coliforms and E. coli Bacteria in Drinking Water and Source Water as Required in National Primary Drinking Water Regulations,” August 2001, available from CPI International, Inc., 5580 Skylane Blvd., Santa Rosa, CA, 95403, telephone (800) 878-7654, Fax (707) 545-7901, Internet address http://www.cpiinternational.com.

(4) [Reserved]

(5) Public water systems must conduct fecal coliform analysis in accordance with the following procedure. When the MTF Technique or Presence-Absence (PA) Coliform Test is used to test for total coliforms, shake the lactose-positive presumptive tube or P-A vigorously and transfer the growth with a sterile 3-mm loop or sterile applicator stick into brilliant green lactose bile broth and EC medium to determine the presence of total and fecal coliforms, respectively. For EPA-approved analytical methods which use a membrane filter, transfer the total coliform-positive culture by one of the following methods: remove the membrane containing the total coliform colonies from the substrate with a sterile forceps and carefully curl and insert the membrane into a tube of EC medium (the laboratory may first remove a small portion of selected colonies for verification), swab the entire membrane filter surface with a sterile cotton swab and transfer the inoculum to EC medium (do not leave the cotton swab in the EC medium), or inoculate individual total coliform-positive colonies into EC Medium. Gently shake the inoculated tubes of EC medium to insure adequate mixing and incubate in a waterbath at 44.5 ±0.2 °C for 24 ±2 hours. Gas production of any amount in the inner fermentation tube of the EC medium indicates a positive fecal coliform test. The preparation of EC medium is described in Method 9221E (paragraph 1a) in Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), and 20th edition (1998); the cited method in any one of these three editions may be used. Public water systems need only determine the presence or absence of fecal coliforms; a determination of fecal coliform density is not required.

(6) Public water systems must conduct analysis of Escherichia coli in accordance with one of the following analytical methods or one of the alternative methods listed in appendix A to subpart C of this part.

(i) EC medium supplemented with 50 µg/mL of 4-methylumbelliferyl-beta-D-glucuronide (MUG) (final concentration), as described in Method 9222G in Standard Methods for the Examination of Water and Wastewater, 19th edition (1995) and 20th edition (1998). Either edition may be used. Alternatively, the 18th edition (1992) may be used if at least 10 mL of EC medium, as described in paragraph (f)(5) of this section, is supplemented with 50 µg/mL of MUG before autoclaving. The inner inverted fermentation tube may be omitted. If the 18th edition is used, apply the procedure in paragraph (f)(5) of this section for transferring a total coliform-positive culture to EC medium supplemented with MUG, incubate the tube at 44.5 ±0.2 °C for 24 ±2 hours, and then observe fluorescence with an ultraviolet light (366 nm) in the dark. If fluorescence is visible, E. coli are present.

(ii) Nutrient agar supplemented with 100 µg/mL of 4-methylumbelliferyl-beta-D-glucuronide (MUG) (final concentration), as described in Method 9222G in Standard Methods for the Examination of Water and Wastewater, 19th edition (1995) and 20th edition (1998). Either edition may be used for determining if a total coliform-positive sample, as determined by a membrane filter technique, contains E. coli. Alternatively, the 18th edition (1992) may be used if the membrane filter containing a total coliform-positive colony(ies) is transferred to nutrient agar, as described in Method 9221B (paragraph 3) of Standard Methods (18th edition), supplemented with 100 µg/mL of MUG. If the 18th edition is used, incubate the agar plate at 35 °C for 4 hours and then observe the colony(ies) under ultraviolet light (366 nm) in the dark for fluorescence. If fluorescence is visible, E. coli are present.

(iii) Minimal Medium ONPG-MUG (MMO-MUG) Test, as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Detection of Total Coliforms and Escherichia coli from Drinking Water: Comparison with Presence-Absence Techniques” (Edberg et al.), Applied and Environmental Microbiology, Volume 55, pp. 1003-1008, April 1989. (Note: The Autoanalysis Colilert System is an MMO-MUG test). If the MMO-MUG test is total coliform-positive after a 24-hour incubation, test the medium for fluorescence with a 366-nm ultraviolet light (preferably with a 6-watt lamp) in the dark. If fluorescence is observed, the sample is E. coli-positive. If fluorescence is questionable (cannot be definitively read) after 24 hours incubation, incubate the culture for an additional four hours (but not to exceed 28 hours total), and again test the medium for fluorescence. The MMO-MUG Test with hepes buffer in lieu of phosphate buffer is the only approved formulation for the detection of E. coli.

(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.

(v) The membrane filter method with MI agar, a description of which is cited in footnote 6 to the table in paragraph (f)(3) of this section.

(vi) E*Colite® Test, a description of which is cited in footnote 10 to the table at paragraph (f)(3) of this section.

(vii) m-ColiBlue24® Test, a description of which is cited in footnote 11 to the table in paragraph (f)(3) of this section.

(viii) Readycult® Coliforms 100 Presence/Absence Test, a description of which is cited in footnote 13 to the table at paragraph (f)(3) of this section.

(ix) Membrane Filter Technique using Chromocult® Coliform Agar, a description of which is cited in footnote 14 to the table at paragraph (f)(3) of this section.

(x) Colitag®, a description of which is cited in footnote 15 to the table at paragraph (f)(3) of this section.

(7) As an option to paragraph (f)(6)(iii) of this section, a system with a total coliform-positive, MUG-negative, MMO-MUG test may further analyze the culture for the presence of E. coli by transferring a 0.1 ml, 28-hour MMO-MUG culture to EC Medium + MUG with a pipet. The formulation and incubation conditions of EC Medium + MUG, and observation of the results are described in paragraph (f)(6)(i) of this section.

(8) The following materials are incorporated by reference in this section with the approval of the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the analytical methods cited in Standard Methods for the Examination of Water and Wastewater (18th, 19th, and 20th editions) may be obtained from the American Public Health Association et al.; 1015 Fifteenth Street, NW., Washington, DC 20005-2605. Copies of the MMO-MUG Test, as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Escherichia coli from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method” (Edberg et al.) may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, CO 80235. Copies of the MMO-MUG Test as set forth in the article “National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Escherichia coli from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method” (Edberg et al.) may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, CO 80235. A description of the Colisure Test may be obtained from the Millipore Corp., Technical Services Department, 80 Ashby Road, Bedford, MA 01730. Copies may be inspected at EPA's Drinking Water Docket; 401 M St., SW.; Washington, DC 20460, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html.

(g) Response to violation. (1) A public water system which has exceeded the MCL for total coliforms in §141.63 must report the violation to the State no later than the end of the next business day after it learns of the violation, and notify the public in accordance with subpart Q.

(2) A public water system which has failed to comply with a coliform monitoring requirement, including the sanitary survey requirement, must report the monitoring violation to the State within ten days after the system discovers the violation, and notify the public in accordance with subpart Q.

(h) The provisions of paragraphs (a) and (d) of this section are applicable until March 31, 2016. The provisions of paragraphs (b), (c), (e), (f), and (g) of this section are applicable until all required repeat monitoring under paragraph (b) of this section and fecal coliform or E. coli testing under paragraph (e) of this section that was initiated by a total coliform-positive sample taken before April 1, 2016 is completed, as well as analytical method, reporting, recordkeeping, public notification, and consumer confidence report requirements associated with that monitoring and testing. Beginning April 1, 2016, the provisions of subpart Y of this part are applicable, with systems required to begin regular monitoring at the same frequency as the system-specific frequency required on March 31, 2016.

[54 FR 27562, June 29, 1989]

Editorial Note: For Federal Register citations affecting §141.21, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

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§141.22   Turbidity sampling and analytical requirements.

The requirements in this section apply to unfiltered systems until December 30, 1991, unless the State has determined prior to that date, in writing pursuant to section 1412(b)(7)(iii), that filtration is required. The requirements in this section apply to filtered systems until June 29, 1993. The requirements in this section apply to unfiltered systems that the State has determined, in writing pursuant to section 1412(b)(7)(C)(iii), must install filtration, until June 29, 1993, or until filtration is installed, whichever is later.

(a) Samples shall be taken by suppliers of water for both community and non-community water systems at a representative entry point(s) to the water distribution system at least once per day, for the purposes of making turbidity measurements to determine compliance with §141.13. If the State determines that a reduced sampling frequency in a non-community will not pose a risk to public health, it can reduce the required sampling frequency. The option of reducing the turbidity frequency shall be permitted only in those public water systems that practice disinfection and which maintain an active residual disinfectant in the distribution system, and in those cases where the State has indicated in writing that no unreasonable risk to health existed under the circumstances of this option. Turbidity measurements shall be made as directed in §141.74(a)(1).

(b) If the result of a turbidity analysis indicates that the maximum allowable limit has been exceeded, the sampling and measurement shall be confirmed by resampling as soon as practicable and preferably within one hour. If the repeat sample confirms that the maximum allowable limit has been exceeded, the supplier of water shall report to the State within 48 hours. The repeat sample shall be the sample used for the purpose of calculating the monthly average. If the monthly average of the daily samples exceeds the maximum allowable limit, or if the average of two samples taken on consecutive days exceeds 5 TU, the supplier of water shall report to the State and notify the public as directed in §141.31 and subpart Q.

(c) Sampling for non-community water systems shall begin within two years after the effective date of this part.

(d) The requirements of this §141.22 shall apply only to public water systems which use water obtained in whole or in part from surface sources.

(e) The State has the authority to determine compliance or initiate enforcement action based upon analytical results or other information compiled by their sanctioned representatives and agencies.

[40 FR 59570, Dec. 24, 1975, as amended at 45 FR 57344, Aug. 27, 1980; 47 FR 8998, Mar. 3, 1982; 47 FR 10998, Mar. 12, 1982; 54 FR 27527, June 29, 1989; 59 FR 62466, Dec. 5, 1994; 65 FR 26022, May 4, 2000]

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§141.23   Inorganic chemical sampling and analytical requirements.

Community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in §141.62 in accordance with this section. Non-transient, non-community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in §141.62 in accordance with this section. Transient, non-community water systems shall conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in §§141.11 and 141.62 (as appropriate) in accordance with this section.

(a) Monitoring shall be conducted as follows:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point) beginning in the initial compliance period. The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

(2) Surface water systems shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point which is representative of each source after treatment (hereafter called a sampling point) beginning in the initial compliance period. The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

Note: For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.

(3) If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

(4) The State may reduce the total number of samples which must be analyzed by allowing the use of compositing. Composite samples from a maximum of five samples are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory.

(i) If the concentration in the composite sample is greater than or equal to one-fifth of the MCL of any inorganic chemical, then a follow-up sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants which exceeded one-fifth of the MCL in the composite sample. Detection limits for each analytical method and MCLs for each inorganic contaminant are the following:

Detection Limits for Inorganic Contaminants

ContaminantMCL (mg/l)MethodologyDetection limit (mg/l)
Antimony0.006Atomic Absorption; Furnace0.003
   Atomic Absorption; Platform0.00085
   ICP-Mass Spectrometry0.0004
   Hydride-Atomic Absorption0.001
Arsenic0.0106Atomic Absorption; Furnace0.001
   Atomic Absorption; Platform—Stabilized Temperature0.00057
   Atomic Absorption; Gaseous Hydride0.001
   ICP-Mass Spectrometry0.00148
Asbestos7 MFL1Transmission Electron Microscopy0.01 MFL
Barium2Atomic Absorption; furnace technique0.002
   Atomic Absorption; direct aspiration0.1
   Inductively Coupled Plasma0.002 (0.001)
Beryllium0.004Atomic Absorption; Furnace0.0002
   Atomic Absorption; Platform0.000025
   Inductively Coupled Plasma20.0003
   ICP-Mass Spectrometry0.0003
Cadmium0.005Atomic Absorption; furnace technique0.0001
   Inductively Coupled Plasma0.001
Chromium0.1Atomic Absorption; furnace technique0.001
   Inductively Coupled Plasma0.007 (0.001)
Cyanide0.2Distillation, Spectrophotometric30.02
   Distillation, Automated, Spectrophotometric30.005
   Distillation, Amenable, Spectrophotometric40.02
   Distillation, Selective Electrode3 40.05
   UV, Distillation, Spectrophotometric90.0005
   Micro Distillation, Flow Injection, Spectrophotometric30.0006
   Ligand Exchange with Amperometry40.0005
Mercury0.002Manual Cold Vapor Technique0.0002
   Automated Cold Vapor Technique0.0002
NickelxlAtomic Absorption; Furnace0.001
   Atomic Absorption; Platform0.00065
   Inductively Coupled Plasma20.005
   ICP-Mass Spectrometry0.0005
Nitrate10 (as N)Manual Cadmium Reduction0.01
   Automated Hydrazine Reduction0.01
   Automated Cadmium Reduction0.05
   Ion Selective Electrode1
   Ion Chromatography0.01
   Capillary Ion Electrophoresis0.076
Nitrite1 (as N)Spectrophotometric0.01
   Automated Cadmium Reduction0.05
   Manual Cadmium Reduction0.01
   Ion Chromatography0.004
   Capillary Ion Electrophoresis0.103
Selenium0.05Atomic Absorption; furnace0.002
   Atomic Absorption; gaseous hydride0.002
Thallium0.002Atomic Absorption; Furnace0.001
   Atomic Absorption; Platform0.00075
   ICP-Mass Spectrometry0.0003

1MFL = million fibers per liter >10 µm.

2Using a 2X preconcentration step as noted in Method 200.7. Lower MDLs may be achieved when using a 4X preconcentration.

3Screening method for total cyanides.

4 Measures “free” cyanides when distillation, digestion, or ligand exchange is omitted.

5Lower MDLs are reported using stabilized temperature graphite furnace atomic absorption.

6The value for arsenic is effective January 23, 2006. Unit then, the MCL is 0.05 mg/L.

7The MDL reported for EPA method 200.9 (Atomic Absorption; Platform—Stablized Temperature) was determined using a 2x concentration step during sample digestion. The MDL determined for samples analyzed using direct analyses (i.e., no sample digestion) will be higher. Using multiple depositions, EPA 200.9 is capable of obtaining MDL of 0.0001 mg/L.

8Using selective ion monitoring, EPA Method 200.8 (ICP-MS) is capable of obtaining a MDL of 0.0001 mg/L.

9Measures total cyanides when UV-digestor is used, and “free” cyanides when UV-digestor is bypassed.

(ii) If the population served by the system is >3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.

(iii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.

(5) The frequency of monitoring for asbestos shall be in accordance with paragraph (b) of this section: the frequency of monitoring for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be in accordance with paragraph (c) of this section; the frequency of monitoring for nitrate shall be in accordance with paragraph (d) of this section; and the frequency of monitoring for nitrite shall be in accordance with paragraph (e) of this section.

(b) The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in §141.62(b) shall be conducted as follows:

(1) Each community and non-transient, non-community water system is required to monitor for asbestos during the first three-year compliance period of each nine-year compliance cycle beginning in the compliance period starting January 1, 1993.

(2) If the system believes it is not vulnerable to either asbestos contamination in its source water or due to corrosion of asbestos-cement pipe, or both, it may apply to the State for a waiver of the monitoring requirement in paragraph (b)(1) of this section. If the State grants the waiver, the system is not required to monitor.

(3) The State may grant a waiver based on a consideration of the following factors:

(i) Potential asbestos contamination of the water source, and

(ii) The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.

(4) A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver must monitor in accordance with the provisions of paragraph (b)(1) of this section.

(5) A system vulnerable to asbestos contamination due solely to corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

(6) A system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of paragraph (a) of this section.

(7) A system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

(8) A system which exceeds the maximum contaminant levels as determined in §141.23(i) of this section shall monitor quarterly beginning in the next quarter after the violation occurred.

(9) The State may decrease the quarterly monitoring requirement to the frequency specified in paragraph (b)(1) of this section provided the State has determined that the system is reliably and consistently below the maximum contaminant level. In no case can a State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface (or combined surface/ground) water system takes a minimum of four quarterly samples.

(10) If monitoring data collected after January 1, 1990 are generally consistent with the requirements of §141.23(b), then the State may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.

(c) The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in §141.62 for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be as follows:

(1) Groundwater systems shall take one sample at each sampling point during each compliance period. Surface water systems (or combined surface/ground) shall take one sample annually at each sampling point.

(2) The system may apply to the State for a waiver from the monitoring frequencies specified in paragraph (c)(1) of this section. States may grant a public water system a waiver for monitoring of cyanide, provided that the State determines that the system is not vulnerable due to lack of any industrial source of cyanide.

(3) A condition of the waiver shall require that a system shall take a minimum of one sample while the waiver is effective. The term during which the waiver is effective shall not exceed one compliance cycle (i.e., nine years).

(4) The State may grant a waiver provided surface water systems have monitored annually for at least three years and groundwater systems have conducted a minimum of three rounds of monitoring. (At least one sample shall have been taken since January 1, 1990). Both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Systems that use a new water source are not eligible for a waiver until three rounds of monitoring from the new source have been completed.

(5) In determining the appropriate reduced monitoring frequency, the State shall consider:

(i) Reported concentrations from all previous monitoring;

(ii) The degree of variation in reported concentrations; and

(iii) Other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system's configuration, changes in the system's operating procedures, or changes in stream flows or characteristics.

(6) A decision by the State to grant a waiver shall be made in writing and shall set forth the basis for the determination. The determination may be initiated by the State or upon an application by the public water system. The public water system shall specify the basis for its request. The State shall review and, where appropriate, revise its determination of the appropriate monitoring frequency when the system submits new monitoring data or when other data relevant to the system's appropriate monitoring frequency become available.

(7) Systems which exceed the maximum contaminant levels as calculated in §141.23(i) of this section shall monitor quarterly beginning in the next quarter after the violation occurred.

(8) The State may decrease the quarterly monitoring requirement to the frequencies specified in paragraphs (c)(1) and (c)(2) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case can a State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.

(9) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.

(d) All public water systems (community; non-transient, non-community; and transient, non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrate in §141.62.

(1) Community and non-transient, non-community water systems served by groundwater systems shall monitor annually beginning January 1, 1993; systems served by surface water shall monitor quarterly beginning January 1, 1993.

(2) For community and non-transient, non-community water systems, the repeat monitoring frequency for groundwater systems shall be quarterly for at least one year following any one sample in which the concentration is ≥50 percent of the MCL. The State may allow a groundwater system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than the MCL.

(3) For community and non-transient, non-community water systems, the State may allow a surface water system to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are <50 percent of the MCL. A surface water system shall return to quarterly monitoring if any one sample is ≥50 percent of the MCL.

(4) Each transient non-community water system shall monitor annually beginning January 1, 1993.

(5) After the initial round of quarterly sampling is completed, each community and non-transient non-community system which is monitoring annually shall take subsequent samples during the quarter(s) which previously resulted in the highest analytical result.

(e) All public water systems (community; non-transient, non-community; and transient, non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrite in §141.62(b).

(1) All public water systems shall take one sample at each sampling point in the compliance period beginning January 1, 1993 and ending December 31, 1995.

(2) After the initial sample, systems where an analytical result for nitrite is <50 percent of the MCL shall monitor at the frequency specified by the State.

(3) For community, non-transient, non-community, and transient non-community water systems, the repeat monitoring frequency for any water system shall be quarterly for at least one year following any one sample in which the concentration is ≥50 percent of the MCL. The State may allow a system to reduce the sampling frequency to annually after determining the system is reliably and consistently less than the MCL.

(4) Systems which are monitoring annually shall take each subsequent sample during the quarter(s) which previously resulted in the highest analytical result.

(f) Confirmation samples:

(1) Where the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium indicate an exceedance of the maximum contaminant level, the State may require that one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point.

(2) Where nitrate or nitrite sampling results indicate an exceedance of the maximum contaminant level, the system shall take a confirmation sample within 24 hours of the system's receipt of notification of the analytical results of the first sample. Systems unable to comply with the 24-hour sampling requirement must immediately notify persons served by the public water system in accordance with §141.202 and meet other Tier 1 public notification requirements under subpart Q of this part. Systems exercising this option must take and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample.

(3) If a State-required confirmation sample is taken for any contaminant, then the results of the initial and confirmation sample shall be averaged. The resulting average shall be used to determine the system's compliance in accordance with paragraph (i) of this section. States have the discretion to delete results of obvious sampling errors.

(g) The State may require more frequent monitoring than specified in paragraphs (b), (c), (d) and (e) of this section or may require confirmation samples for positive and negative results at its discretion.

(h) Systems may apply to the State to conduct more frequent monitoring than the minimum monitoring frequencies specified in this section.

(i) Compliance with §141.11 or §141.62(b) (as appropriate) shall be determined based on the analytical result(s) obtained at each sampling point.

(1) For systems which are conducting monitoring at a frequency greater than annual, compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium is determined by a running annual average at any sampling point. If the average at any sampling point is greater than the MCL, then the system is out of compliance. If any one sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.

(2) For systems which are monitoring annually, or less frequently, the system is out of compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium if the level of a contaminant is greater than the MCL. If confirmation samples are required by the State, the determination of compliance will be based on the annual average of the initial MCL exceedance and any State-required confirmation samples. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.

(3) Compliance with the maximum contaminant levels for nitrate and nitrate is determined based on one sample if the levels of these contaminants are below the MCLs. If the levels of nitrate and/or nitrite exceed the MCLs in the initial sample, a confirmation sample is required in accordance with paragraph (f)(2) of this section, and compliance shall be determined based on the average of the initial and confirmation samples.

(4) Arsenic sampling results will be reported to the nearest 0.001 mg/L.

(j) Each public water system shall monitor at the time designated by the State during each compliance period.

(k) Inorganic analysis:

(1) Analysis for the following contaminants shall be conducted in accordance with the methods in the following table, or the alternative methods listed in appendix A to subpart C of this part, 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 is available from the National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242-0419 or http://www.epa.gov/nscep/.

ContaminantMethodology13EPAASTM3SM4 (18th, 19th ed.)SM4 (20th ed.)SM Online22Other
1. AlkalinityTitrimetricD1067-92, 02 B2320 B2320 B2320 B-97
   Electrometric titrationI-1030-85 5
2. AntimonyInductively Coupled Plasma (ICP)—Mass Spectrometry200.82
   Hydride-Atomic AbsorptionD3697-92, 02
   Atomic Absorption; Platform200.92
   Atomic Absorption; Furnace3113 B3113 B-99
3. Arsenic14ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; FurnaceD2972-97, 03 C3113 B3113 B-99
   Hydride Atomic AbsorptionD1972-97, 03 B3114 B3114 B-97
4. AsbestosTransmission Electron Microscopy100.19
   Transmission Electron Microscopy100.210
5. BariumInductively Coupled Plasma200.723120 B3120 B3120 B-99
   ICP-Mass Spectrometry200.82
   Atomic Absorption; Direct3111D3111 D-99
   Atomic Absorption; Furnace3113 B3113 B-99
6. BerylliumInductively Coupled Plasma200.723120 B3120 B3120 B-99
   ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; FurnaceD3645-97, 03 B3113 B3113 B-99
7. CadmiumInductively Coupled Plasma200.72
   ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; Furnace3113 B3113 B-99
8. CalciumEDTA titrimetricD511-93, 03 A3500-Ca D3500-Ca B3500-Ca B-97
   Atomic Absorption; Direct AspirationD511-93, 03 B3111 B3111 B-99
   Inductively Coupled Plasma200.723120 B3120 B3120 B-99
   Ion ChromatographyD6919-03
9. ChromiumInductively Coupled Plasma200.723120 B3120 B3120 B-99
   ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; Furnace3113 B3113 B-99
10. CopperAtomic Absorption; FurnaceD1688-95, 02 C3113 B3113 B-99
   Atomic Absorption; Direct AspirationD1688-95, 02 A3111 B3111 B-99
   Inductively Coupled Plasma200.723120 B3120 B3120 B-99
   ICP-Mass spectrometry200.82
   Atomic Absorption; Platform200.92
11. ConductivityConductanceD1125-95 (Reapproved 1999) A2510 B2510 B2510 B-97
12. CyanideManual Distillation followed byD2036-98 A4500-CN C4500-CN C
   Spectrophotometric, AmenableD2036-98 B4500-CN G4500-CN G4500-CN G-99
   Spectro-photometric ManualD2036-98 A4500-CN E4500-CN E4500-CN E-99I-3300-855
   Spectro-photometric Semi-automated335.46
   Selective Electrode4500-CN F4500-CN F4500-CN F-99
   UV, Distillation, SpectrophotometricKelada-0117
   Micro Distillation, Flow Injection, SpectrophotometricQuikChem 10-204-00-1-X18
   Ligand Exchange and Amperometry21D6888-04OIA-1677, DW20
13. FluorideIon Chromatography300.06, 300.119D4327-97, 034110 B4110 B4110 B-00
   Manual Distill.; Color. SPADNS4500-F B, D4500-F B, D4500-F B, D-97
   Manual ElectrodeD1179-93, 99 B4500-F C4500-F C4500-F C-97
   Automated Electrode380-75WE11
   Automated Alizarin4500-F E4500-F E4500-F E-97129-71W11
   Capillary Ion ElectrophoresisD6508, Rev. 223
14. LeadAtomic Absorption; FurnaceD3559-96, 03 D3113 B3113 B-99
   ICP-Mass spectrometry200.82
   Atomic Absorption; Platform200.92
   Differential Pulse Anodic Stripping VoltametryMethod 100116
15. MagnesiumAtomic AbsorptionD511-93, 03 B3111 B3111 B-99
   ICP200.723120 B3120 B3120 B-99
   Complexation Titrimetric MethodsD511-93, 03 A3500-Mg E3500-Mg B3500-Mg B-97
   Ion ChromatographyD6919-03
16. MercuryManual, Cold Vapor245.12D3223-97, 023112 B3112 B-99
   Automated, Cold Vapor245.21
   ICP-Mass Spectrometry200.82
17. NickelInductively Coupled Plasma200.723120 B3120 B3120 B-99
   ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; Direct3111 B3111 B-99
   Atomic Absorption; Furnace3113 B3113 B-99
18. NitrateIon Chromatography300.06, 300.119D4327-97, 034110 B4110 B4110 B-00B-10118
   Automated Cadmium Reduction353.26D3867-90 A4500-NO3 F4500-NO3 F4500-NO3 F-00
Ion Selective Electrode4500-NO3 D4500-NO3 D4500-NO3 D-006017
   Manual Cadmium ReductionD3867-90 B4500-NO3 E4500-NO3 E4500-NO3 E-00
   Capillary Ion ElectrophoresisD6508-00.
19. NitriteIon Chromatography300.06, 300.119D4327-97, 034110 B4110 B4110 B-00B-10118
   Automated Cadmium Reduction353.26D3867-90 A4500-NO3 F4500-NO3 F4500-NO3 F-00
   Manual Cadmium ReductionD3867-90 B4500-NO3 E4500-NO3 E4500-NO3 E-00
   Spectrophotometric4500-NO2 B4500-NO2 B4500-NO2 B-00
Capillary Ion ElectrophoresisD6508-00
20. Ortho-phosphateColorimetric, Automated, Ascorbic Acid365.164500-P F4500-P F
Colorimetric, ascorbic acid, single reagentD515-88 A4500-P E4500-P E
   Colorimetric Phosphomolybdate; Automated-segmented flow; Automated DiscreteI-1601-855
I-2601-905
I-2598-855
   Ion Chromatography300.06, 300.119D4327-97, 034110 B4110 B4110 B-00
   Capillary Ion ElectrophoresisD6508-00
21. pHElectrometric150.1, 150.21D1293-95, 994500-H+ B4500-H+ B4500-H+ B-00
22. SeleniumHydride-Atomic AbsorptionD3859-98, 03 A3114 B3114 B-97
ICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92
   Atomic Absorption; FurnaceD3859-98, 03 B3113 B3113 B-99
23. SilicaColorimetric, Molybdate BlueI-1700-855
   Automated-segmented FlowI-2700-855
   ColorimetricD859-94, 00
   Molybdosilicate4500-Si D4500-SiO2 C4500-SiO2 C-97
   Heteropoly blue4500-Si E4500-SiO2 D4500-SiO2 D-97
   Automated for Molybdate-reactive Silica4500-Si F4500-SiO2 E4500-SiO2 E-97
   Inductively Coupled Plasma200.723120 B3120 B3120 B-99
24. SodiumInductively Coupled Plasma200.72
   Atomic Absorption; Direct Aspiration3111 B3111 B-99
   Ion ChromatographyD6919-03
25. TemperatureThermometric255025502550-00
26. ThalliumICP-Mass Spectrometry200.82
   Atomic Absorption; Platform200.92

The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents listed in footnotes 1-11, 16-20, and 22-23 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., Room 3334, Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html.

1“Methods for Chemical Analysis of Water and Wastes,” EPA/600/4-79/020, March 1983. 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, PB95-125472.

3Annual Book of ASTM Standards, ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, http://www.astm.org.; Annual Book of ASTM Standards 1994, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 1996, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 1999, Vols. 11.01 and 11.02; Annual Book of ASTM Standards 2003, Vols. 11.01 and 11.02.

4Standard Methods for the Examination of Water and Wastewater, American Public Health Association, 800 I Street NW., Washington, DC 20001-3710; Standard Methods for the Examination of Water and Wastewater, 18th edition (1992); Standard Methods for the Examination of Water and Wastewater, 19th edition (1995); Standard Methods for the Examination of Water and Wastewater, 20th edition (1998).The following methods from this edition cannot be used: 3111 B, 3111 D, 3113 B, and 3114 B.

5U.S. Geological Survey, Federal Center, Box 25286, Denver, CO 80225-0425; Methods for Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Inorganic and Organic Constituents in Water and Fluvial Sediment, Open File Report 93-125, 1993; Techniques of Water Resources Investigation of the U.S. Geological Survey, Book 5, Chapter A-1, 3rd edition, 1989.

6“Methods for the Determination of Inorganic Substances in Environmental Samples,” EPA/600/R-93/100, August 1993. Available as Technical Report PB94-120821 at National Technical Information Service (NTIS), 5301 Shawnee Road, Alexandria, VA 22312. http://www.ntis.gov.

7The 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. Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA 02129.

8Method B-1011. “Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion Chromatography,” August, 1987. Copies may be obtained from Waters Corporation, Technical Services Division, 34 Maple Street, Milford, MA 01757, Telephone: 508/482-2963, Fax: 508/482-4056.

9Method 100.1, “Analytical Method For Determination of Asbestos Fibers in Water,” EPA/600/4-83/043, EPA, September 1983. Available at NTIS, PB83-260471.

10Method 100.2, “Determination of Asbestos Structure Over 10-μm In Length In Drinking Water,” EPA/600/R-94/134, June 1994. Available at NTIS, PB94-201902.

11Industrial 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. Copies may be obtained from Bran & Luebbe, 1025 Busch Parkway, Buffalo Grove, IL 60089.

12Unfiltered, no digestion or hydrolysis.

13Because MDLs reported in EPA Methods 200.7 and 200.9 were determined using a 2x preconcentration step during sample digestion, MDLs determined when samples are analyzed by direct analysis (i.e., no sample digestion) will be higher. For direct analysis of cadmium and arsenic by Method 200.7, and arsenic by Method 3120 B, sample preconcentration using pneumatic nebulization may be required to achieve lower detection limits. Preconcentration may also be required for direct analysis of antimony, lead, and thallium by Method 200.9; antimony and lead by Method 3113 B; and lead by Method D3559-90D, unless multiple in-furnace depositions are made.

14If ultrasonic nebulization is used in the determination of arsenic by Method 200.8, the arsenic must be in the pentavalent state to provide uniform signal response. For direct analysis of arsenic with Method 200.8 using ultrasonic nebulization, samples and standards must contain 1 mg/L of sodium hypochlorite.

15[Reserved]

16The description for Method Number 1001 for lead is available from Palintest, LTD, 21 Kenton Lands Road, P.O. Box 18395, Erlanger, KY 41018. Or from the Hach Company, P.O. Box 389, Loveland, CO 80539.

17The description for the Kelada-01 Method, “Kelada Automated Test Methods for Total Cyanide, Acid Dissociable Cyanide, And Thiocyanate,” Revision 1.2, August 2001, EPA # 821-B-01-009 for cyanide is available from the National Technical Information Service (NTIS), PB 2001-108275, 5285 Port Royal Road, Springfield, VA 22161. The toll free telephone number is 800-553-6847. Note: A 450-W UV lamp may be used in this method instead of the 550-W lamp specified if it provides performance within the quality control (QC) acceptance criteria of the method in a given instrument. Similarly, modified flow cell configurations and flow conditions may be used in the method, provided that the QC acceptance criteria are met.

18The description for the QuikChem Method 10-204-00-1-X, “Digestion and distillation of total cyanide in drinking and wastewaters using MICRO DIST and determination of cyanide by flow injection analysis,” Revision 2.1, November 30, 2000, for cyanide is available from Lachat Instruments, 6645 W. Mill Rd., Milwaukee, WI 53218. Telephone: 414-358-4200.

19“Methods for the Determination of Organic and Inorganic Compounds in Drinking Water,” Vol. 1, EPA 815-R-00-014, August 2000. Available as Technical Report PB2000-106981 at National Technical Information Service (NTIS), 5301 Shawnee Road, Alexandria, VA 22312. http://www.ntis.gov.

20Method OIA-1677, DW “Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry,” January 2004. EPA-821-R-04-001, Available from ALPKEM, A Division of OI Analytical, P.O. Box 9010, College Station, TX 77842-9010.

21Sulfide levels below those detected using lead acetate paper may produce positive method interferences. Test samples using a more sensitive sulfide method to determine if a sulfide interference is present, and treat samples accordingly.

22Standard Methods Online, American Public Health Association, 800 I Street NW., Washington, DC 20001, available at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.

(2) Sample collection for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite, selenium, and thallium under this section shall be conducted using the sample preservation, container, and maximum holding time procedures specified in the table below:

ContaminantPreservative1Container2Time3
AntimonyHNO3P or G6 months
ArsenicConc HNO3 to pH <2P or G6 months
Asbestos4 °CP or G48 hours4
BariumHNO3P or G6 months
BerylliumHNO3P or G6 months
CadmiumHNO3P or G6 months
ChromiumHNO3P or G6 months
Cyanide4 °C, NaOHP or G14 days
FluorideNoneP or G1 month
MercuryHNO3P or G28 days
NickelHNO3P or G6 months
Nitrate4 °CP or G48 hours5
Nitrate-Nitrite6H2SO4P or G28 days
Nitrite4 °CP or G48 hours
SeleniumHNO3P or G6 months
ThalliumHNO3P or G6 months

1For cyanide determinations samples must be adjusted with sodium hydroxide to pH 12 at the time off collection. When chilling is indicated the sample must be shipped and stored at 4 °C or less. Acidification of nitrate or metals samples may be with a concentrated acid or a dilute (50% by volume) solution of the applicable concentrated acid. Acidification of samples for metals analysis is encouraged and allowed at the laboratory rather than at the time of sampling provided the shipping time and other instructions in Section 8.3 of EPA Methods 200.7 or 200.8 or 200.9 are followed.

2P = plastic, hard or soft; G = glass, hard or soft.

3In all cases samples should be analyzed as soon after collection as possible. Follow additional (if any) information on preservation, containers or holding times that is specified in method.

4Instructions for containers, preservation procedures and holding times as specified in Method 100.2 must be adhered to for all compliance analyses including those conducted with Method 100.1.

5If the sample is chlorinated, the holding time for an unacidified sample kept at 4 °C is extended to 14 days.

6Nitrate-Nitrite refers to a measurement of total nitrate.

(3) Analysis under this section shall only be conducted by laboratories that have been certified by EPA or the State. Laboratories may conduct sample analysis under provisional certification until January 1, 1996. To receive certification to conduct analyses for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite and selenium and thallium, the laboratory must:

(i) Analyze Performance Evaluation (PE) samples provided by EPA, the State or by a third party (with the approval of the State or EPA) at least once a year.

(ii) For each contaminant that has been included in the PE sample and for each method for which the laboratory desires certification achieve quantitative results on the analyses that are within the following acceptance limits:

Contaminant Acceptance limit
Antimony±30 at ≥0.006 mg/1
Arsenic±30 at ≥0.003 mg/L
Asbestos2 standard deviations based on study statistics.
Barium±15% at ≥0.15 mg/1
Beryllium±15% at ≥0.001 mg/1
Cadmium±20% at ≥0.002 mg/1
Chromium±15% at ≥0.01 mg/1
Cyanide±25% at ≥0.1 mg/1
Fluoride±10% at ≥1 to 10 mg/1
Mercury±30% at ≥0.0005 mg/1
Nickel±15% at ≥0.01 mg/1
Nitrate±10% at ≥0.4 mg/1
Nitrite±15% at ≥0.4 mg/1
Selenium±20% at ≥0.01 mg/1
Thallium±30% at ≥0.002 mg/1

(l) Analyses for the purpose of determining compliance with §141.11 shall be conducted using the requirements specified in paragraphs (l) through (q) of this section.

(1) Analyses for all community water systems utilizing surface water sources shall be completed by June 24, 1978. These analyses shall be repeated at yearly intervals.

(2) Analyses for all community water systems utilizing only ground water sources shall be completed by June 24, 1979. These analyses shall be repeated at three-year intervals.

(3) For non-community water systems, whether supplied by surface or ground sources, analyses for nitrate shall be completed by December 24, 1980. These analyses shall be repeated at intervals determined by the State.

(4) The State has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.

(m) If the result of an analysis made under paragraph (l) of this section indicates that the level of any contaminant listed in §141.11 exceeds the maximum contaminant level, the supplier of the water shall report to the State within 7 days and initiate three additional analyses at the same sampling point within one month.

(n) When the average of four analyses made pursuant to paragraph (m) of this section, rounded to the same number of significant figures as the maximum contaminant level for the substance in question, exceeds the maximum contaminant level, the supplier of water shall notify the State pursuant to §141.31 and give notice to the public pursuant to subpart Q. Monitoring after public notification shall be at a frequency designated by the State and shall continue until the maximum contaminant level has not been exceeded in two successive samples or until a monitoring schedule as a condition to a variance, exemption or enforcement action shall become effective.

(o) The provisions of paragraphs (m) and (n) of this section notwithstanding, compliance with the maximum contaminant level for nitrate shall be determined on the basis of the mean of two analyses. When a level exceeding the maximum contaminant level for nitrate is found, a second analysis shall be initiated within 24 hours, and if the mean of the two analyses exceeds the maximum contaminant level, the supplier of water shall report his findings to the State pursuant to §141.31 and shall notify the public pursuant to subpart Q.

(p) For the initial analyses required by paragraph (l) (1), (2) or (3) of this section, data for surface waters acquired within one year prior to the effective date and data for ground waters acquired within 3 years prior to the effective date of this part may be substituted at the discretion of the State.

(q) [Reserved]

[56 FR 3579, Jan. 30, 1991]

Editorial Note: For Federal Register citations affecting §141.23, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

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§141.24   Organic chemicals, sampling and analytical requirements.

(a)-(d) [Reserved]

(e) Analyses for the contaminants in this section shall be conducted using the methods listed in the following table, or the alternative methods listed in appendix A to subpart C of this part, or their equivalent as determined by EPA.

(1) The following documents are incorporated by reference. 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 inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue, NW., EPA West, Room 3334, Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html. Method 508A and 515.1 are in Methods for the Determination of Organic Compounds in Drinking Water, EPA/600/4-88-039, December 1988, Revised, July 1991. Methods 547, 550 and 550.1 are in Methods for the Determination of Organic Compounds in Drinking Water—Supplement I, EPA/600-4-90-020, July 1990. Methods 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. Methods 502.2, 504.1, 505, 506, 507, 508, 508.1, 515.2, 524.2 525.2, 531.1, 551.1 and 552.2 are in Methods for the Determination of Organic Compounds in Drinking Water--Supplement III, EPA/600/R-95-131, August 1995. 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, PB95-261616 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 Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), or 20th edition (1998), American Public Health Association (APHA); any of these three editions may be used. Method 6610 shall be followed in accordance with Standard Methods for the Examination of Water and Wastewater, (18th Edition Supplement) (1994), or with the 19th edition (1995) or 20th edition (1998) of Standard Methods for the Examination of Water and Wastewater; any of these publications may be used. The APHA documents are available from APHA, 1015 Fifteenth Street NW., Washington, DC 20005. Other required analytical test procedures germane to the conduct of these analyses are contained in Technical Notes on Drinking Water Methods, EPA/600/R-94-173, October 1994, NTIS PB95-104766. EPA Methods 515.3 and 549.2 are available from U.S. Environmental Protection Agency, National Exposure Research Laboratory (NERL)-Cincinnati, 26 West Martin Luther King Drive, Cincinnati, OH 45268. ASTM Method D 5317-93, 98 (Reapproved 2003) is available in the Annual Book of ASTM Standards, (1999), Vol. 11.02, ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, any edition containing the cited version of the method may be used. EPA Method 515.4, “Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Microextraction, Derivatization and Fast Gas Chromatography with Electron Capture Detection,” Revision 1.0, April 2000, EPA/815/B-00/001 and EPA Method 552.3, “Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Microextraction, Derivatization, and Gas Chromatography with Electron Capture Detection,” Revision 1.0, July 2003, EPA 815-B-03-002, can be accessed and downloaded directly online at http://www.epa.gov/safewater/methods/sourcalt.html. Syngenta Method AG-625, “Atrazine in Drinking Water by Immunoassay,” February 2001, is available from Syngenta Crop Protection, Inc., 410 Swing Road, P.O. Box 18300, Greensboro, NC 27419. Telephone: 336-632-6000. Method 531.2 “Measurement of N-methylcarbamoyloximes and N-methylcarbamates in Water by Direct Aqueous Injection HPLC with Postcolumn Derivatization,” Revision 1.0, September 2001, EPA 815-B-01-002, can be accessed and downloaded directly online at http://www.epa.gov/safewater/methods/sourcalt.html.

ContaminantEPA method Standard methods ASTM Other
1. Benzene502.2, 524.2
2. Carbon tetrachloride502.2, 524.2, 551.1
3. Chlorobenzene502.2, 524.2
4. 1,2-Dichlorobenzene502.2, 524.2
5. 1,4-Dichlorobenzene502.2, 524.2
6. 1,2-Dichloroethane502.2, 524.2
7. cis-Dichloroethylene502.2, 524.2
8. trans-Dichloroethylene502.2, 524.2
9. Dichloromethane502.2, 524.2
10. 1,2-Dichloropropane502.2, 524.2
11. Ethylbenzene502.2, 524.2
12. Styrene502.2, 524.2
13. Tetrachloroethylene502.2, 524.2, 551.1
14. 1,1,1-Trichloroethane502.2, 524.2, 551.1
15. Trichloroethylene502.2, 524.2, 551.1
16. Toluene502.2, 524.2
17. 1,2,4-Trichlorobenzene502.2, 524.2
18. 1,1-Dichloroethylene502.2, 524.2
19. 1,1,2-Trichloroethane502.2, 524.2, 551.1
20. Vinyl chloride502.2, 524.2
21. Xylenes (total)502.2, 524.2
22. 2,3,7,8-TCDD (dioxin)1613
23. 2,4-D4 (as acids, salts, and esters)515.2, 555, 515.1, 515.3, 515.4D5317-93, 98 (Reapproved 2003)
24. 2,4,5-TP4 (Silvex)515.2, 555, 515.1, 515.3, 515.4D5317-93, 98 (Reapproved 2003)
25. Alachlor2507, 525.2, 508.1, 505, 551.1
26. Atrazine2507, 525.2, 508.1, 505, 551.1Syngenta5 AG-625
27. Benzo(a)pyrene525.2, 550, 550.1
28. Carbofuran531.1, 531.26610
29. Chlordane508, 525.2, 508.1, 505
30. Dalapon552.1 515.1, 552.2, 515.3, 515.4, 552.3
31. Di(2-ethylhexyl)adipate506, 525.2
32. Di(2-ethylhexyl)phthalate506, 525.2
33. Dibromochloropropane (DBCP)504.1, 551.1
34. Dinoseb4515.2, 555, 515.1, 515.3, 515.4
35. Diquat549.2
36. Endothall548.1
37. Endrin508, 525.2, 508.1, 505, 551.1
38. Ethylene dibromide (EDB)504.1, 551.1
39. Glyphosate5476651
40. Heptachlor508, 525.2, 508.1, 505, 551.1
41. Heptachlor Epoxide508, 525.2, 508.1, 505, 551.1
42. Hexachlorobenzene508, 525.2, 508.1, 505, 551.1
43. Hexachlorocyclopentadiene508, 525.2, 508.1, 505, 551.1
44. Lindane508, 525.2, 508.1, 505, 551.1
45. Methoxychlor508, 525.2, 508.1, 505, 551.1
46. Oxamyl531.1, 531.26610
47. PCBs3 (as decachlorobiphenyl)508A
48. PCBs3 (as Aroclors)508.1, 508, 525.2, 505
49. Pentachlorophenol515.2, 525.2, 555, 515.1, 515.3, 515.4D5317-93, 98 (Reapproved 2003)
50. Picloram4515.2, 555, 515.1, 515.3, 515.4D5317-93, 98 (Reapproved 2003)
51. Simazine2507, 525.2, 508.1, 505, 551.1
52. Toxaphene508, 508.1, 525.2, 505
53. Total Trihalomethanes502.2, 524.2, 551.1

1[Reserved]

2Substitution of the detector specified in Method 505, 507, 508 or 508.1 for the purpose of achieving lower detection limits is allowed as follows. Either an electron capture or nitrogen phosphorous detector may be used provided all regulatory requirements and quality control criteria are met.

3PCBs are qualitatively identified as Aroclors and measured for compliance purposes as decachlorobiphenyl. Users of Method 505 may have more difficulty in achieving the required detection limits than users of Methods 508.1, 525.2 or 508.

4Accurate determination of the chlorinated esters requires hydrolysis of the sample as described in EPA Methods 515.1, 515.2, 515.3, 515.4 and 555 and ASTM Method D5317-93.

5This method may not be used for the analysis of atrazine in any system where chlorine dioxide is used for drinking water treatment. In samples from all other systems, any result for atrazine generated by Method AG-625 that is greater than one-half the maximum contaminant level (MCL) (in other words, greater than 0.0015mg/L or 1.5 μg/L) must be confirmed using another approved method for this contaminant and should use additional volume of the original sample collected for compliance monitoring. In instances where a result from Method AG-625 triggers such confirmatory testing, the confirmatory result is to be used to determine compliance.

(2) [Reserved]

(f) Beginning with the initial compliance period, analysis of the contaminants listed in §141.61(a) (1) through (21) for the purpose of determining compliance with the maximum contaminant level shall be conducted as follows:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.

(2) Surface water systems (or combined surface/ground) shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.

(3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water representative of all sources is being used).

(4) Each community and non-transient non-community water system shall take four consecutive quarterly samples for each contaminant listed in §141.61(a) (2) through (21) during each compliance period, beginning in the initial compliance period.

(5) If the initial monitoring for contaminants listed in §141.61(a) (1) through (8) and the monitoring for the contaminants listed in §141.61(a) (9) through (21) as allowed in paragraph (f)(18) has been completed by December 31, 1992, and the system did not detect any contaminant listed in §141.61(a) (1) through (21), then each ground and surface water system shall take one sample annually beginning with the initial compliance period.

(6) After a minimum of three years of annual sampling, the State may allow groundwater systems with no previous detection of any contaiminant listed in §141.61(a) to take one sample during each compliance period.

(7) Each community and non-transient non-community ground water system which does not detect a contaminant listed in §141.61(a) (1) through (21) may apply to the State for a waiver from the requirements of paragraphs (f)(5) and (f)(6) of this section after completing the initial monitoring. (For purposes of this section, detection is defined as ≥0.0005 mg/l.) A waiver shall be effective for no more than six years (two compliance periods). States may also issue waivers to small systems for the initial round of monitoring for 1,2,4-trichlorobenzene.

(8) A State may grant a waiver after evaluating the following factor(s):

(i) Knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the system. If a determination by the State reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted.

(ii) If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.

(A) Previous analytical results.

(B) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities.

(C) The environmental persistence and transport of the contaminants.

(D) The number of persons served by the public water system and the proximity of a smaller system to a larger system.

(E) How well the water source is protected against contamination, such as whether it is a surface or groundwater system. Groundwater systems must consider factors such as depth of the well, the type of soil, and wellhead protection. Surface water systems must consider watershed protection.

(9) As a condition of the waiver a groundwater system must take one sample at each sampling point during the time the waiver is effective (i.e., one sample during two compliance periods or six years) and update its vulnerability assessment considering the factors listed in paragraph (f)(8) of this section. Based on this vulnerability assessment the State must reconfirm that the system is non-vulnerable. If the State does not make this reconfirmation within three years of the initial determination, then the waiver is invalidated and the system is required to sample annually as specified in paragraph (5) of this section.

(10) Each community and non-transient non-community surface water system which does not detect a contaminant listed in §141.61(a) (1) through (21) may apply to the State for a waiver from the requirements of (f)(5) of this section after completing the initial monitoring. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Systems meeting this criterion must be determined by the State to be non-vulnerable based on a vulnerability assessment during each compliance period. Each system receiving a waiver shall sample at the frequency specified by the State (if any).

(11) If a contaminant listed in §141.61(a) (2) through (21) is detected at a level exceeding 0.0005 mg/l in any sample, then:

(i) The system must monitor quarterly at each sampling point which resulted in a detection.

(ii) The State may decrease the quarterly monitoring requirement speci fied in paragraph (f)(11)(i) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.

(iii) If the State determines that the system is reliably and consistently below the MCL, the State may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter(s) which previously yielded the highest analytical result.

(iv) Systems which have three consecutive annual samples with no detection of a contaminant may apply to the State for a waiver as specified in paragraph (f)(7) of this section.

(v) Groundwater systems which have detected one or more of the following two-carbon organic compounds: trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1-dichloroethylene shall monitor quarterly for vinyl chloride. A vinyl chloride sample shall be taken at each sampling point at which one or more of the two-carbon organic compounds was detected. If the results of the first analysis do not detect vinyl chloride, the State may reduce the quarterly monitoring frequency of vinyl chloride monitoring to one sample during each compliance period. Surface water systems are required to monitor for vinyl chloride as specified by the State.

(12) Systems which violate the requirements of §141.61(a) (1) through (21), as determined by paragraph (f)(15) of this section, must monitor quarterly. After a minimum of four consecutive quarterly samples which show the system is in compliance as specified in paragraph (f)(15) of this section the system and the State determines that the system is reliably and consistently below the maximum contaminant level, the system may monitor at the frequency and times specified in paragraph (f)(11)(iii) of this section.

(13) The State may require a confirmation sample for positive or negative results. If a confirmation sample is required by the State, the result must be averaged with the first sampling result and the average is used for the compliance determination as specified by paragraph (f)(15). States have discretion to delete results of obvious sampling errors from this calculation.

(14) The State may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

(i) If the concentration in the composite sample is greater than or equal to 0.0005 mg/l for any contaminant listed in §141.61(a), then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that contaminant.

(ii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.

(iii) If the population served by the system is >3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.

(iv) Compositing samples prior to GC analysis.

(A) Add 5 ml or equal larger amounts of each sample (up to 5 samples are allowed) to a 25 ml glass syringe. Special precautions must be made to maintain zero headspace in the syringe.

(B) The samples must be cooled at 4 °C during this step to minimize volatilization losses.

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

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

(E) If less than five samples are used for compositing, a proportionately small syringe may be used.

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

(A) Inject 5-ml or equal larger amounts of each aqueous sample (up to 5 samples are allowed) into a 25-ml purging device using the sample introduction technique described in the method.

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

(C) Purge and desorb as described in the method.

(15) Compliance with §141.61(a) (1) through (21) shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.

(ii) Systems monitoring annually or less frequently whose sample result exceeds the MCL must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.

(iii) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

(iv) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.

(v) If a sample result is less than the detection limit, zero will be used to calculate the annual average.

(16) [Reserved]

(17) Analysis under this section shall only be conducted by laboratories that are certified by EPA or the State according to the following conditions (laboratories may conduct sample analysis under provisional certification until January 1, 1996):

(i) To receive certification to conduct analyses for the contaminants in §141.61(a) (2) through (21) the laboratory must:

(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.

(B) Achieve the quantitative acceptance limits under paragraphs (f)(17)(i)(C) and (D) of this section for at least 80 percent of the regulated organic contaminants included in the PE sample.

(C) Achieve quantitative results on the analyses performed under paragraph (f)(17)(i)(A) of this section that are within ±20% of the actual amount of the substances in the Performance Evaluation sample when the actual amount is greater than or equal to 0.010 mg/l.

(D) Achieve quantitative results on the analyses performed under paragraph (f)(17)(i)(A) of this section that are within ±40 percent of the actual amount of the substances in the Performance Evaluation sample when the actual amount is less than 0.010 mg/l.

(E) Achieve a method detection limit of 0.0005 mg/l, according to the procedures in appendix B of part 136.

(ii) To receive certification to conduct analyses for vinyl chloride, the laboratory must:

(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.

(B) Achieve quantitative results on the analyses performed under paragraph (f)(17)(ii)(A) of this section that are within ±40 percent of the actual amount of vinyl chloride in the Performance Evaluation sample.

(C) Achieve a method detection limit of 0.0005 mg/l, according to the procedures in appendix B of part 136.

(D) Obtain certification for the contaminants listed in §141.61(a)(2) through (21).

(18) States may allow the use of monitoring data collected after January 1, 1988, required under section 1445 of the Act for purposes of initial monitoring compliance. If the data are generally consistent with the other requirements of this section, the State may use these data (i.e., a single sample rather than four quarterly samples) to satisfy the initial monitoring requirement of paragraph (f)(4) of this section. Systems which use grandfathered samples and did not detect any contaminant listed §141.61(a)(2) through (21) shall begin monitoring annually in accordance with paragraph (f)(5) of this section beginning with the initial compliance period.

(19) States may increase required monitoring where necessary to detect variations within the system.

(20) Each certified laboratory must determine the method detection limit (MDL), as defined in appendix B to part 136, at which it is capable of detecting VOCs. The acceptable MDL is 0.0005 mg/l. This concentration is the detection concentration for purposes of this section.

(21) Each public water system shall monitor at the time designated by the State within each compliance period.

(22) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.

(g) [Reserved]

(h) Analysis of the contaminants listed in §141.61(c) for the purposes of determining compliance with the maximum contaminant level shall be conducted as follows, with the exception that no monitoring is required for aldicarb, aldicarb sulfoxide or aldicarb sulfone:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

(2) Surface water systems shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

Note: For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.

(3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water representative of all sources is being used).

(4) Monitoring frequency: (i) Each community and non-transient non-community water system shall take four consecutive quarterly samples for each contaminant listed in §141.61(c) during each compliance period beginning with the initial compliance period.

(ii) Systems serving more than 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of two quarterly samples in one year during each repeat compliance period.

(iii) Systems serving less than or equal to 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

(5) Each community and non-transient water system may apply to the State for a waiver from the requirement of paragraph (h)(4) of this section. A system must reapply for a waiver for each compliance period.

(6) A State may grant a waiver after evaluating the following factor(s): Knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the system. If a determination by the State reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted. If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.

(i) Previous analytical results.

(ii) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities. Non-point sources include the use of pesticides to control insect and weed pests on agricultural areas, forest lands, home and gardens, and other land application uses.

(iii) The environmental persistence and transport of the pesticide or PCBs.

(iv) How well the water source is protected against contamination due to such factors as depth of the well and the type of soil and the integrity of the well casing.

(v) Elevated nitrate levels at the water supply source.

(vi) Use of PCBs in equipment used in the production, storage, or distribution of water (i.e., PCBs used in pumps, transformers, etc.).

(7) If an organic contaminant listed in §141.61(c) is detected (as defined by paragraph (h)(18) of this section) in any sample, then:

(i) Each system must monitor quarterly at each sampling point which resulted in a detection.

(ii) The State may decrease the quarterly monitoring requirement specified in paragraph (h)(7)(i) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the State make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.

(iii) After the State determines the system is reliably and consistently below the maximum contaminant level the State may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter that previously yielded the highest analytical result.

(iv) Systems which have 3 consecutive annual samples with no detection of a contaminant may apply to the State for a waiver as specified in paragraph (h)(6) of this section.

(v) If the monitoring results in detection of one or more of certain related contaminants (heptachlor and heptachlor epoxide), then subsequent monitoring shall analyze for all related contaminants.

(8) Systems which violate the requirements of §141.61(c) as determined by paragraph (h)(11) of this section must monitor quarterly. After a minimum of four quarterly samples show the system is in compliance and the State determines the system is reliably and consistently below the MCL, as specified in paragraph (h)(11) of this section, the system shall monitor at the frequency specified in paragraph (h)(7)(iii) of this section.

(9) The State may require a confirmation sample for positive or negative results. If a confirmation sample is required by the State, the result must be averaged with the first sampling result and the average used for the compliance determination as specified by paragraph (h)(11) of this section. States have discretion to delete results of obvious sampling errors from this calculation.

(10) The State may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

(i) If the concentration in the composite sample detects one or more contaminants listed in §141.61(c), then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that contaminant.

(ii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of resampling. The duplicates must be analyzed and the results reported to the State within 14 days after completion of the composite analysis or before the holding time for the initial sample is exceeded whichever is sooner.

(iii) If the population served by the system is >3,300 persons, then compositing may only be permitted by the State at sampling points within a single system. In systems serving ≤3,300 persons, the State may permit compositing among different systems provided the 5-sample limit is maintained.

(11) Compliance with §141.61(c) shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.

(ii) Systems monitoring annually or less frequently whose sample result exceeds the regulatory detection level as defined by paragraph (h)(18) of this section must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.

(iii) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

(iv) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.

(v) If a sample result is less than the detection limit, zero will be used to calculate the annual average.

(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 508.1, 525.2, 508 or 505. Users of Method 505 may have more difficulty in achieving the required Aroclor detection limits than users of Methods 508.1, 525.2 or 508.

(ii) If PCBs (as one of seven Aroclors) are detected (as designated in this paragraph) in any sample analyzed using Method 505 or 508, the system shall reanalyze the sample using Method 508A to quantitate PCBs (as decachlorobiphenyl).

Aroclor Detection limit (mg/l)
10160.00008
12210.02
12320.0005
12420.0003
12480.0001
12540.0001
12600.0002

(iii) Compliance with the PCB MCL shall be determined based upon the quantitative results of analyses using Method 508A.

(14) If monitoring data collected after January 1, 1990, are generally consistent with the requirements of §141.24(h), then the State may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.

(15) The State may increase the required monitoring frequency, where necessary, to detect variations within the system (e.g., fluctuations in concentration due to seasonal use, changes in water source).

(16) The State has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.

(17) Each public water system shall monitor at the time designated by the State within each compliance period.

(18) Detection as used in this paragraph shall be defined as greater than or equal to the following concentrations for each contaminant.

Contaminant Detection limit (mg/l)
Alachlor.0002
Aldicarb.0005
Aldicarb sulfoxide.0005
Aldicarb sulfone.0008
Atrazine.0001
Benzo[a]pyrene.00002
Carbofuran.0009
Chlordane.0002
Dalapon.001
1,2-Dibromo-3-chloropropane (DBCP).00002
Di (2-ethylhexyl) adipate.0006
Di (2-ethylhexyl) phthalate.0006
Dinoseb.0002
Diquat.0004
2,4-D.0001
Endothall.009
Endrin.00001
Ethylene dibromide (EDB).00001
Glyphosate.006
Heptachlor.00004
Heptachlor epoxide.00002
Hexachlorobenzene.0001
Hexachlorocyclopentadiene.0001
Lindane.00002
Methoxychlor.0001
Oxamyl.002
Picloram.0001
Polychlorinated biphenyls (PCBs) (as decachlorobiphenyl).0001
Pentachlorophenol.00004
Simazine.00007
Toxaphene.001
2,3,7,8-TCDD (Dioxin).000000005
2,4,5-TP (Silvex).0002

(19) Anaylsis under this section shall only be conducted by laboratories that have received certification by EPA or the State and have met the following conditions:

(i) To receive certification to conduct analyses for the contaminants in §141.61(c) the laboratory must:

(A) Analyze Performance Evaluation (PE) samples provided by EPA, the State, or by a third party (with the approval of the State or EPA) at least once a year by each method for which the laboratory desires certification.

(B) For each contaminant that has been included in the PE sample achieve quantitative results on the analyses that are within the following acceptance limits:

ContaminantAcceptance limits (percent)
DBCP±40
EDB±40.
Alachlor±45.
Atrazine±45.
Benzo[a]pyrene2 standard deviations.
Carbofuran±45.
Chlordane±45.
Dalapon2 standard deviations.
Di(2-ethylhexyl)adipate2 standard deviations.
Di(2-ethylhexyl)phthalate2 standard deviations.
Dinoseb2 standard deviations.
Diquat2 standard deviations.
Endothall2 standard deviations.
Endrin±30.
Glyphosate2 standard deviations.
Heptachlor±45.
Heptachlor epoxide±45.
Hexachlorobenzene2 standard deviations.
Hexachloro- cyclopentadiene2 standard deviations.
Lindane±45.
Methoxychlor±45.
Oxamyl2 standard deviations.
PCBs (as Decachlorobiphenyl)0-200.
Picloram2 standard deviations.
Simazine2 standard deviations.
Toxaphene±45.
Aldicarb2 standard deviations.
Aldicarb sulfoxide2 standard deviations.
Aldicarb sulfone2 standard deviations.
Pentachlorophenol±50.
2,3,7,8-TCDD (Dioxin)2 standard deviations.
2,4-D±50.
2,4,5-TP (Silvex)±50.

(ii) [Reserved]

(20) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the State. The system must also comply with the initial sampling frequencies specified by the State to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this section.

(Approved by the Office of Management and Budget under control number 2040-0090)

[40 FR 59570, Dec. 24, 1975]

Editorial Note: For Federal Register citations affecting §141.24, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

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§141.25   Analytical methods for radioactivity.

(a) Analysis for the following contaminants shall be conducted to determine compliance with §141.66 (radioactivity) in accordance with the methods in the following table, or the alternative methods listed in appendix A to subpart C this part, or their equivalent determined by EPA in accordance with §141.27.

Contaminant Methodology Reference (Method of Page Number)
EPA1 EPA2 EPA3 EPA4 SM5 ASTM6 USGS7 DOE8 Other
Naturally Occurring:
Gross alpha11 and betaEvaporation900.0p. 100-01p. 1302, 7110 B, 7110 B-00R-1120-76
Gross alpha11Coprecipitation00-027110 C, 7110 C-00
Radium 226Radon emanation903.1p. 16Ra-04p. 19305, 7500-Ra C, 7500-Ra C-01D3454-97R-1141-76Ra-04NY9,
   Radiochemical903.0p. 13Ra-03304, 7500-Ra B, 7500-Ra B-01D2460-97R-1140-76GA14
Radium 228Radiochemical904.0p. 24Ra-05p. 197500-Ra D, 7500-Ra D-01R-1142-76NY9,
NJ10,
GA14
Uranium12Radiochemical908.07500-U B, 7500-U B-00
   Fluorometric908.17500-U C (17th Ed.)D2907-97R-1180-76, R-1181-76U-04
   ICP-MS200.8133125D5673-03
   Alpha Spectrometry00-07p. 337500-U C (18th, 19th, or 20th Ed.), 7500-U C-00D3972-97, 02R-1182-76U-02
   Laser PhosphorimetryD5174-97, 02
Man-Made:
Radioactive CesiumRadiochemical901.0p. 47500-Cs B, 7500-Cs B-00D2459-72R-1111-76
   Gamma Ray Spectrometry901.1p. 927120, 7120-97D3649-91, 98aR-1110-764.5.2.3
Radioactive IodineRadiochemical902.0p. 67500-I B, 7500-I B-00
   p. 97500-I C, 7500-I C-00
   7500-I D, 7500-I D-00D3649-91, 98a
   Gamma Ray Spectrometry901.1p. 927120, 7120-97D4785-93, 00a4.5.2.3
Radioactive Strontium 89, 90Radiochemical905.0p. 29Sr-04p. 65303, 7500-Sr B, 7500-Sr B-01R-1160-76Sr-01, Sr-02
TritiumLiquid Scintillation906.0p. 34H-02p. 87306, 7500-3H B, 7500-3H B-00D4107-91, 98 (Reapproved 2002)R-1171-76
Gamma EmittersGamma Ray Spectrometry901.1p. 927120, 7120-97D3649-91, 98aR-1110-76Ga-01-R
   902.07500-Cs B, 7500-Cs B-00D4785-93, 00a
   901.07500-I B, 7500-I B-00

The procedures shall be done in accordance with the documents listed below. The incorporation by reference of documents 1 through 10 and 13 through 14 was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at 800-426-4791. Documents may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW., Room 3334 , Washington, DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html.

1“Prescribed Procedures for the Measurement of Radioactivity in Drinking Water,” EPA 600/4-80-032, August 1980. Available at the U.S. Department of Commerce, National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161 (Telephone 800-553-6847), PB 80-224744.

2“Interim Radiochemical Methodology for Drinking Water,” EPA 600/4-75-008 (revised), March 1976. Available NTIS, ibid.

3“Radiochemistry Procedures Manual,” EPA 520/5-84-006, December 1987. Available NTIS, ibid.

4“Radiochemical Analytical Procedures for Analysis of Environmental Samples,” March 1979. Available at NTIS, ibid. EMSL LV 053917.

5“Standard Methods for the Examination of Water and Wastewater,” 13th, 17th, 18th, 19th or 20th edition, 1971, 1989, 1992, 1995, 1998. Available at American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005. Methods 302, 303, 304, 305 and 306 are only in the 13th edition. Methods 7110B, 7500-Ra B, 7500-Ra C, 7500-Ra D, 7500-U B, 7500-Cs B, 7500-I B, 7500-I C, 7500-I D, 7500-Sr B, and 7500-3H B are in the 17th, 18th, 19th and 20th editions. Method 7110 C is in the 18th, 19th and 20th editions. Method 7500-U C Fluorometric Uranium is only in the 17th Edition, and 7500-U C Alpha spectrometry is only in the 18th, 19th and 20th editions. Method 7120 is only in the 19th and 20th editions. Method 3125 is only in the 20th edition. Methods 7110 B-00, 7110 C-00, 7500-Ra B-01, 7500-Ra C-01, 7500-Ra D-01, 7500-U B-00, 7500-U C-00, 7500-I B-00, 7500-I C-00, 7500-I D-00, 7120-97, 7500-Sr B-01, and 7500-3H B-00 are available online at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.

6Annual Book of ASTM Standards, Vol. 11.01 and 11.02, 2002; ASTM International; any year containing the cited version of the method may be used. Copies of these two volumes and the 2003 version of D 5673-03 may be obtained from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.

7“Methods for Determination of Radioactive Substances in Water and Fluvial Sediments,” Chapter A5 in Book 5 of Techniques of Water-Resources Investigations of the United States Geological Survey, 1977. Available at U.S. Geological Survey (USGS) Information Services, Box 25286, Federal Center, Denver, CO 80225-0425.

8“EML Procedures Manual,” 28th (1997) or 27th (1990) Editions, Volumes 1 and 2; either edition may be used. In the 27th Edition Method Ra-04 is listed as Ra-05 and Method Ga-01-R is listed as Sect. 4.5.2.3. Available at the Environmental Measurements Laboratory, U.S. Department of Energy (DOE), 376 Hudson Street, New York, NY 10014-3621.

9“Determination of Ra-226 and Ra-228 (Ra-02),” January 1980, Revised June 1982. Available at Radiological Sciences Institute for Laboratories and Research, New York State Department of Health, Empire State Plaza, Albany, NY 12201.

10“Determination of Radium 228 in Drinking Water,” August 1980. Available at State of New Jersey, Department of Environmental Protection, Division of Environmental Quality, Bureau of Radiation and Inorganic Analytical Services, 9 Ewing Street, Trenton, NJ 08625.

11Natural uranium and thorium-230 are approved as gross alpha calibration standards for gross alpha with co-precipitation and evaporation methods; americium-241 is approved with co-precipitation methods.

12If uranium (U) is determined by mass, a 0.67 pCi/μg of uranium conversion factor must be used. This conversion factor is based on the 1:1 activity ratio of U-234 and U-238 that is characteristic of naturally occurring uranium.

13“Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry,” Revision 5.4, which is published in “Methods for the Determination of Metals in Environmental Samples—Supplement I,”' EPA 600-R-94-111, May 1994. Available at NTIS, PB 95-125472.

14“The Determination of Radium-226 and Radium-228 in Drinking Water by Gamma-ray Spectrometry Using HPGE or Ge(Li) Detectors,” Revision 1.2, December 2004. Available from the Environmental Resources Center, Georgia Institute of Technology, 620 Cherry Street, Atlanta, GA 30332-0335, USA, Telephone: 404-894-3776. This method may be used to analyze for radium-226 and radium-228 in samples collected after January 1, 2005 to satisfy the radium-226 and radium-228 monitoring requirements specified at 40 CFR 141.26.

(b) When the identification and measurement of radionuclides other than those listed in paragraph (a) of this section is required, the following references are to be used, except in cases where alternative methods have been approved in accordance with §141.27.

(1) Procedures for Radiochemical Analysis of Nuclear Reactor Aqueous Solutions, H. L. Krieger and S. Gold, EPA-R4-73-014. USEPA, Cincinnati, Ohio, May 1973.

(2) HASL Procedure Manual, Edited by John H. Harley. HASL 300, ERDA Health and Safety Laboratory, New York, NY., 1973.

(c) For the purpose of monitoring radioactivity concentrations in drinking water, the required sensitivity of the radioanalysis is defined in terms of a detection limit. The detection limit shall be that concentration which can be counted with a precision of plus or minus 100 percent at the 95 percent confidence level (1.96σ where σ is the standard deviation of the net counting rate of the sample).

(1) To determine compliance with §141.66(b), (c), and (e) the detection limit shall not exceed the concentrations in Table B to this paragraph.

Table B—Detection Limits for Gross Alpha Particle Activity, Radium 226, Radium 228, and Uranium

Contaminant Detection
limit
Gross alpha particle activity3 pCi/L.
Radium 2261 pCi/L.
Radium 2281 pCi/L.
Uranium1 µg/L

(2) To determine compliance with §141.66(d) the detection limits shall not exceed the concentrations listed in Table C to this paragraph.

Table C—Detection Limits for Man-made Beta Particle and Photon Emitters

RadionuclideDetection limit
Tritium1,000 pCi/1.
Strontium-8910 pCi/1.
Strontium-902 pCi/1.
Iodine-1311 pCi/1.
Cesium-13410 pCi/1.
Gross beta4 pCi/1.
Other radionuclides 110 of the applicable limit.

(d) To judge compliance with the maximum contaminant levels listed in §141.66, averages of data shall be used and shall be rounded to the same number of significant figures as the maximum contaminant level for the substance in question.

(e) The State has the authority to determine compliance or initiate enforcement action based upon analytical results or other information compiled by their sanctioned representatives and agencies.

[41 FR 28404, July 9, 1976, as amended at 45 FR 57345, Aug. 27, 1980; 62 FR 10173, Mar. 5, 1997; 65 FR 76745, Dec. 7, 2000; 67 FR 65250, Oct. 23, 2002; 69 FR 38855, June 29, 2004; 69 FR 52180, Aug. 25, 2004; 72 FR 11245, Mar. 12, 2007; 74 FR 30958, June 29, 2009]

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§141.26   Monitoring frequency and compliance requirements for radionuclides in community water systems.

(a) Monitoring and compliance requirements for gross alpha particle activity, radium-226, radium-228, and uranium. (1) Community water systems (CWSs) must conduct initial monitoring to determine compliance with §141.66(b), (c), and (e) by December 31, 2007. For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, uranium, and beta particle and photon radioactivity in drinking water, “detection limit” is defined as in §141.25(c).

(i) Applicability and sampling location for existing community water systems or sources. All existing CWSs using ground water, surface water or systems using both ground and surface water (for the purpose of this section hereafter referred to as systems) must sample at every entry point to the distribution system that is representative of all sources being used (hereafter called a sampling point) under normal operating conditions. The system must take each sample at the same sampling point unless conditions make another sampling point more representative of each source or the State has designated a distribution system location, in accordance with paragraph (a)(2)(ii)(C) of this section.

(ii) Applicability and sampling location for new community water systems or sources. All new CWSs or CWSs that use a new source of water must begin to conduct initial monitoring for the new source within the first quarter after initiating use of the source. CWSs must conduct more frequent monitoring when ordered by the State in the event of possible contamination or when changes in the distribution system or treatment processes occur which may increase the concentration of radioactivity in finished water.

(2) Initial monitoring: Systems must conduct initial monitoring for gross alpha particle activity, radium-226, radium-228, and uranium as follows:

(i) Systems without acceptable historical data, as defined below, must collect four consecutive quarterly samples at all sampling points before December 31, 2007.

(ii) Grandfathering of data: States may allow historical monitoring data collected at a sampling point to satisfy the initial monitoring requirements for that sampling point, for the following situations.

(A) To satisfy initial monitoring requirements, a community water system having only one entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.

(B) To satisfy initial monitoring requirements, a community water system with multiple entry points and having appropriate historical monitoring data for each entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.

(C) To satisfy initial monitoring requirements, a community water system with appropriate historical data for a representative point in the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003, provided that the State finds that the historical data satisfactorily demonstrate that each entry point to the distribution system is expected to be in compliance based upon the historical data and reasonable assumptions about the variability of contaminant levels between entry points. The State must make a written finding indicating how the data conforms to the these requirements.

(iii) For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the State may waive the final two quarters of initial monitoring for a sampling point if the results of the samples from the previous two quarters are below the detection limit.

(iv) If the average of the initial monitoring results for a sampling point is above the MCL, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are at or below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the State.

(3) Reduced monitoring: States may allow community water systems to reduce the future frequency of monitoring from once every three years to once every six or nine years at each sampling point, based on the following criteria.

(i) If the average of the initial monitoring results for each contaminant (i.e., gross alpha particle activity, uranium, radium-226, or radium-228) is below the detection limit specified in Table B, in §141.25(c)(1), the system must collect and analyze for that contaminant using at least one sample at that sampling point every nine years.

(ii) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is at or above the detection limit but at or below 12 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years. For combined radium-226 and radium-228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is at or above the detection limit but at or below 12 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years.

(iii) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is above 12 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years. For combined radium-226 and radium-228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is above 12 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years.

(iv) Systems must use the samples collected during the reduced monitoring period to determine the monitoring frequency for subsequent monitoring periods (e.g., if a system's sampling point is on a nine year monitoring period, and the sample result is above 12 MCL, then the next monitoring period for that sampling point is three years).

(v) If a system has a monitoring result that exceeds the MCL while on reduced monitoring, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the State.

(4) Compositing: To fulfill quarterly monitoring requirements for gross alpha particle activity, radium-226, radium-228, or uranium, a system may composite up to four consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. States will treat analytical results from the composited as the average analytical result to determine compliance with the MCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than 12 MCL, the State may direct the system to take additional quarterly samples before allowing the system to sample under a reduced monitoring schedule.

(5) A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/l. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/l. The gross alpha measurement shall have a confidence interval of 95% (1.65σ, where σ is the standard deviation of the net counting rate of the sample) for radium-226 and uranium. When a system uses a gross alpha particle activity measurement in lieu of a radium-226 and/or uranium measurement, the gross alpha particle activity analytical result will be used to determine the future monitoring frequency for radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 12 the detection limit will be used to determine compliance and the future monitoring frequency.

(b) Monitoring and compliance requirements for beta particle and photon radioactivity. To determine compliance with the maximum contaminant levels in §141.66(d) for beta particle and photon radioactivity, a system must monitor at a frequency as follows:

(1) Community water systems (both surface and ground water) designated by the State as vulnerable must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the State. Systems already designated by the State must continue to sample until the State reviews and either reaffirms or removes the designation.

(i) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 50 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to once every 3 years. Systems must collect all samples required in paragraph (b)(1) of this section during the reduced monitoring period.

(ii) For systems in the vicinity of a nuclear facility, the State may allow the CWS to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the State determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems which are using surveillance data must begin monitoring at the community water system's entry point(s) in accordance with paragraph (b)(1) of this section.

(2) Community water systems (both surface and ground water) designated by the State as utilizing waters contaminated by effluents from nuclear facilities must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the State. Systems already designated by the State as systems using waters contaminated by effluents from nuclear facilities must continue to sample until the State reviews and either reaffirms or removes the designation.

(i) Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples. The former is recommended.

(ii) For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As ordered by the State, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.

(iii) Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples. The latter procedure is recommended.

(iv) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to every 3 years. Systems must collect the same type of samples required in paragraph (b)(2) of this section during the reduced monitoring period.

(v) For systems in the vicinity of a nuclear facility, the State may allow the CWS to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the State determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems which are using surveillance data must begin monitoring at the community water system's entry point(s) in accordance with paragraph (b)(2) of this section.

(3) Community water systems designated by the State to monitor for beta particle and photon radioactivity can not apply to the State for a waiver from the monitoring frequencies specified in paragraph (b)(1) or (b)(2) of this section.

(4) Community water systems may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. Systems are allowed to subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if the screening level is exceeded. The potassium-40 beta particle activity must be calculated by multiplying elemental potassium concentrations (in mg/L) by a factor of 0.82.

(5) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds the appropriate screening level, an analysis of the sample must be performed to identify the major radioactive constituents present in the sample and the appropriate doses must be calculated and summed to determine compliance with §141.66(d)(1), using the formula in §141.66(d)(2). Doses must also be calculated and combined for measured levels of tritium and strontium to determine compliance.

(6) Systems must monitor monthly at the sampling point(s) which exceed the maximum contaminant level in §141.66(d) beginning the month after the exceedance occurs. Systems must continue monthly monitoring until the system has established, by a rolling average of 3 monthly samples, that the MCL is being met. Systems who establish that the MCL is being met must return to quarterly monitoring until they meet the requirements set forth in paragraph (b)(1)(i) or (b)(2)(iv) of this section.

(c) General monitoring and compliance requirements for radionuclides. (1) The State may require more frequent monitoring than specified in paragraphs (a) and (b) of this section, or may require confirmation samples at its discretion. The results of the initial and confirmation samples will be averaged for use in compliance determinations.

(2) Each public water systems shall monitor at the time designated by the State during each compliance period.

(3) Compliance: Compliance with §141.66 (b) through (e) will be determined based on the analytical result(s) obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(i) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point. If the average of any sampling point is greater than the MCL, then the system is out of compliance with the MCL.

(ii) For systems monitoring more than once per year, if any sample result will cause the running average to exceed the MCL at any sample point, the system is out of compliance with the MCL immediately.

(iii) Systems must include all samples taken and analyzed under the provisions of this section in determining compliance, even if that number is greater than the minimum required.

(iv) If a system does not collect all required samples when compliance is based on a running annual average of quarterly samples, compliance will be based on the running average of the samples collected.

(v) If a sample result is less than the detection limit, zero will be used to calculate the annual average, unless a gross alpha particle activity is being used in lieu of radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 12 the detection limit will be used to calculate the annual average.

(4) States have the discretion to delete results of obvious sampling or analytic errors.

(5) If the MCL for radioactivity set forth in §141.66 (b) through (e) is exceeded, the operator of a community water system must give notice to the State pursuant to §141.31 and to the public as required by subpart Q of this part.

[65 FR 76745, Dec. 7, 2000, as amended at 69 FR 38855, June 29, 2004]

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§141.27   Alternate analytical techniques.

(a) With the written permission of the State, concurred in by the Administrator of the U.S. EPA, an alternate analytical technique may be employed. An alternate technique shall be accepted only if it is substantially equivalent to the prescribed test in both precision and accuracy as it relates to the determination of compliance with any MCL. The use of the alternate analytical technique shall not decrease the frequency of monitoring required by this part.

[45 FR 57345, Aug. 27, 1980]

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§141.28   Certified laboratories.

(a) For the purpose of determining compliance with §141.21 through 141.27, 141.30, 141.40, 141.74, 141.89 and 141.402, samples may be considered only if they have been analyzed by a laboratory certified by the State except that measurements of alkalinity, calcium, conductivity, disinfectant residual, orthophosphate, pH, silica, temperature and turbidity may be performed by any person acceptable to the State.

(b) Nothing in this part shall be construed to preclude the State or any duly designated representative of the State from taking samples or from using the results from such samples to determine compliance by a supplier of water with the applicable requirements of this part.

[45 FR 57345, Aug. 27, 1980; 47 FR 10999, Mar. 12, 1982, as amended at 59 FR 34323, July 1, 1994; 64 FR 67465, Dec. 1, 1999; 71 FR 65651, Nov. 8, 2006]

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§141.29   Monitoring of consecutive public water systems.

When a public water system supplies water to one or more other public water systems, the State may modify the monitoring requirements imposed by this part to the extent that the interconnection of the systems justifies treating them as a single system for monitoring purposes. Any modified monitoring shall be conducted pursuant to a schedule specified by the State and concurred in by the Administrator of the U.S. Environmental Protection Agency.

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Appendix A to Subpart C of Part 141—Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act

Only the editions stated in the following table are approved.

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(3)

OrganismMethodologySM 21st Edition1SM 22nd Edition28SM Online3Other
Total ColiformsTotal Coliform Fermentation Technique9221 A, B9221 A, B9221 A,B-06
   Total Coliform Membrane Filter Technique9222 A, B, C
   Presence-Absence (P-A) Coliform Test9221 D
   ONPG-MUG Test92239223 B9223 B-04
   ColitagTMModified ColitagTM13
   Tecta EC/TC33

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(5)

OrganismMethodologySM 22nd Edition28SM Online3
Fecal ColiformsFecal Coliform Procedure9221 E9221 E-06

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(6)

OrganismMethodologySM 20th
Edition6
SM 21st
Edition1
SM 22nd
Edition28
SM Online3Other
E.coliONPG-MUG Test9223 B9223 B9223 B9223 B-97, B-04
   ColitagTMModified ColitagTM13
   Tecta EC/TC33

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.23(k)(1)

ContaminantMethodologyEPA methodSM 21st
edition1
SM 22nd
edition28
SM 23rd
edition49
SM Online3ASTM4Other
AlkalinityTitrimetric2320 B2320 B2320 BD1067-06 B, 11 B, 16 B
AntimonyHydride—Atomic AbsorptionD 3697-07, -12
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
ArsenicAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 2972-08 C, -15 C
   Hydride Atomic Absorption3114 B3114 B3114 B3114 B-09D 2972-08 B, -15 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
BariumInductively Coupled Plasma3120 B3120 B3120 B
   Atomic Absorption; Direct3111 D3111 D3111 D
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
BerylliumInductively Coupled Plasma3120 B3120 B3120 B
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3645-08 B, -15 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CadmiumAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CalciumEDTA titrimetric3500-Ca B3500-Ca B3500-Ca BD 511-09, -14 A
   Atomic Absorption; Direct Aspiration3111 B3111 B3111 BD 511-09, -14 B
   Inductively Coupled Plasma3120 B3120 B3120 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
   Ion ChromatographyD 6919-09
ChromiumInductively Coupled Plasma3120 B3120 B3120 B
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CopperAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 1688-07, -12 C
   Atomic Absorption; Direct Aspiration3111 B3111 B3111 BD 1688-07, -12 A
   Inductively Coupled Plasma3120 B3120 B3120 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
   ColorimetryHach Method 8026;35 Hach Method 10272.36
ConductivityConductance2510 B2510 B2510 BD 1125-14 A
CyanideManual Distillation with MgCl2 followed by:4500-CN C4500-CN C4500-CN C4500-CN C-99D 2036-06 A
   Spectrophotometric, Amenable4500-CN G4500-CN G4500-CN GD 2036-06 B
   Spectrophotometric Manual4500-CN E4500-CN E4500-CN ED2036-06 A
   Selective Electrode4500-CN F4500-CN F4500-CN F
   Gas Chromatography/Mass Spectrometry HeadspaceME355.01.7
FluorideIon Chromatography4110 B4110 B4110 BD 4327-11
   Manual Distillation; Colorimetric SPADNS4500-F B, D4500-F B, D4500-F B, D
   Manual Electrode4500-F C4500-F C4500-F CD 1179-04, 10 B, 16 B
   Automated Alizarin4500-F E4500-F E4500-F E
   Arsenite-Free Colorimetric SPADNSHach SPADNS 2 Method 10225.22
LeadAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3559-08 D, 15 D
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
MagnesiumAtomic Absorption3111 B3111 B3111 BD 511-09, -14 B
   Inductively Coupled Plasma3120 B3120 B3120 B
   Complexation Titrimetric Methods3500-Mg B3500-Mg B3500-Mg BD 511-09, -14 A
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
   Ion ChromatographyD 6919-09
MercuryManual, Cold Vapor3112 B3112 B3112 B3112 B-09D 3223-12
NickelInductively Coupled Plasma3120 B3120 B3120 B
   Atomic Absorption; Direct3111 B3111 B3111 B
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
NitrateIon Chromatography4110 B4110 B4110 BD 4327-11
   Automated Cadmium Reduction4500-NO3 F4500-NO3 F4500-NO3 F
   Manual Cadmium Reduction4500-NO3 E4500-NO3 E4500-NO3 E
   Ion Selective Electrode4500-NO3 D4500-NO3 D4500-NO3 D
   Reduction/ColorimetricSystea Easy
(1-Reagent);8 NECi Nitrate-Reductase.40
   Colorimetric; DirectHach TNTplusTM 835/836 Method 10206.23
   Capillary Ion ElectrophoresisD 6508-15
NitriteIon Chromatography4110 B4110 B4110 BD 4327-11
   Automated Cadmium Reduction4500-NO3 F4500-NO3 F4500-NO3 F
   Manual Cadmium Reduction4500-NO3 E4500-NO3 E4500-NO3 E
   Spectrophotometric4500-NO2 B4500-NO2 B4500-NO2 B
   Reduction/ColorimetricSystea Easy (1-Reagent);8 NECi Nitrate-Reductase.40
   Capillary Ion ElectrophoresisD 6508-15
Ortho-phosphateIon Chromatography4110 B4110 B4110 BD 4327-11
   Colorimetric, ascorbic acid, single reagent4500-P E4500-P E4500-P E4500-P E-99
   Colorimetric, Automated, Ascorbic Acid4500-P F4500-P F4500-P F4500-P F-99Thermo Fisher Discrete Analyzer.41
   Capillary Ion ElectrophoresisD 6508-15
pHElectrometric150.3484500-H+ B4500-H+ B4500-H+ BD 1293-12
SeleniumHydride-Atomic Absorption3114 B3114 B3114 B3114 B-09D 3859-08 A, -15 A
   Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3859-08 B, -15 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
SilicaColorimetricD859-05, 10, 16
   Molybdosilicate4500-SiO2 C4500-SiO2 C4500-SiO2 C
   Heteropoly blue4500-SiO2 D4500-SiO2 D4500-SiO2 D
   Automated for Molybdate-reactive Silica4500-SiO2 E4500-SiO2 E4500-SiO2 E
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
   Inductively Coupled Plasma3120 B3120 B3120 B
SodiumAtomic Absorption; Direct Aspiration3111 B3111 B3111 B
   Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
   Ion ChromatographyD 6919-09
TemperatureThermometric2550255025502550-10

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.24(e)(1)

ContaminantMethodologyEPA methodSM 21st
edition1
SM 22nd
edition,28 SM 23rd
edition49
SM online3
BenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Carbon tetrachloridePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
ChlorobenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichlorobenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,4-DichlorobenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichloroethanePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
cis-DichloroethylenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
trans-DichloroethylenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
DichloromethanePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichloropropanePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
EthylbenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
StyrenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,;9 524.4.29
TetrachloroethylenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,1,1-TrichloroethanePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
TrichloroethylenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
ToluenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2,4-TrichlorobenzenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,1-DichloroethylenePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,1,2-TrichlorethanePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Vinyl chloridePurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Xylenes (total)Purge &Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
2,4-DGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
2,4,5-TP (Silvex)Gas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
AlachlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
AtrazineLiquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)536.25
   Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3,24523.26
Benzo(a)pyreneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
CarbofuranHigh-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection6610 B6610 B6610 B-04.
ChlordaneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
DalaponIon Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
   Gas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
Di(2-ethylhexyl)adipateSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Di(2-ethylhexyl)phthalateSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Dibromochloropropane (DBCP)Purge &Trap/Gas Chromatography/Mass Spectrometry524.3.9
DinosebGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
EndrinSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Ethyl dibromide (EDB)Purge &Trap/Gas Chromatography/Mass Spectrometry524.3.9
GlyphosateHigh-Performance Liquid Chromatography (HPLC) with Post-Column Derivatization and Fluorescence Detection6651 B6651 B6651 B-00, B-05.
HeptachlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Heptachlor EpoxideSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
HexachlorobenzeneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Hexachlorocyclo-pentadieneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
LindaneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
MethoxychlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
OxamylHigh-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection6610 B6610 B6610 B-04.
PCBs (as Aroclors)Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
PentachlorophenolGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
PicloramGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06.
SimazineLiquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)536.25
   Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3,24523.26
ToxapheneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Total TrihalomethanesPurge &Trap/Gas Chromatography/Mass Spectrometry524.3,9524.429

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.25(a)

ContaminantMethodologyEPA
method
SM 21st
edition1
SM 22nd
edition,28
SM 23rd
edition49
ASTM4SM Online3
Naturally Occurring:
Gross alpha and betaEvaporation900.0, Rev. 1.0507110 B7110 B
  Liquid ScintillationD 7283-177110 D-17.
Gross alphaCoprecipitation7110 C7110 C
Radium 226Radon emanation7500-Ra C7500-Ra CD 3454-05
   Radiochemical7500-Ra B7500-Ra BD 2460-07
   Gamma Spectrometry7500-Ra E7500-Ra E-07.
Radium 228Radiochemical7500-Ra D7500-Ra D
   Gamma Spectrometry7500Ra-E7500-Ra E-07.
UraniumRadiochemical7500-U B7500-U B
   ICP-MS3125D 5673-05, 10, 16
   Alpha spectrometry7500-U C7500-U CD 3972-09
   Laser PhosphorimetryD 5174-07
   Alpha Liquid Scintillation SpectrometryD 6239-09
Man-Made:
Radioactive CesiumRadiochemical7500-Cs B7500-Cs B
   Gamma Ray Spectrometry71207120D 3649-06
Radioactive IodineRadiochemical7500-I B7500-I BD 3649-06
         7500-I C7500-I C
         7500-I D7500-I D
   Gamma Ray Spectrometry71207120D 4785-08
Radioactive Strontium 89, 90Radiochemical7500-Sr B7500-Sr B
TritiumLiquid Scintillation7500-3H B7500-3H BD 4107-08
Gamma EmittersGamma Ray71207120D 3649-06
   Spectrometry7500-Cs B7500-Cs BD 4785-08
   7500-I B7500-I B

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.74(a)(1)

OrganismMethodologySM 21st
edition1
SM 22nd
edition28
SM 23rd
edition49
SM Online3Other
Total ColiformTotal Coliform Fermentation Technique9221 A, B, C9221 A, B, C9221 A, B, C9221 A,B,C-06
   Total Coliform Membrane Filter Technique9222 A, B, C9222 A, B, C.
   ONPG-MUG Test92239223 B9223 B9223 B-04.
Fecal ColiformsFecal Coliform Procedure9221 E9221 E9221 E9221 E-06.
   Fecal Coliform Filter Procedure9222 D9222 D9222 D9222 D-06.
Heterotrophic bacteriaPour Plate Method9215 B9215 B9215 B9215 B-04.
TurbidityNephelometric Method2130 B2130 B2130 BHach Method 8195, Rev. 3.0.52
   Laser Nephelometry (on-line)Mitchell M5271,10 Mitchell M5331, Rev. 1.2,42 Lovibond PTV 6000.46
   LED Nephelometry (on-line)Mitchell M5331,11
Mitchell M5331, Rev. 1.2,42 Lovibond PTV 2000.45
   LED Nephelometry (on-line)AMI Turbiwell,15 Lovibond PTV 1000.44
   LED Nephelometry (portable)Orion AQ4500.12
   360° NephelometryHach Method 10258 Rev. 1.0,39 Hach Method 10258, Rev. 2.0.51

Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.74(a)(2)

ResidualMethodologySM 21st
edition1
SM 22nd edition,28 SM 23rd
edition49
ASTM4Other
Free ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
   DPD Ferrous Titrimetric4500-Cl F4500-Cl F
   DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
   Indophenol ColorimetricHach Method 10241.34
   Syringaldazine (FACTS)4500-Cl H4500-Cl H
   On-line Chlorine AnalyzerEPA 334.0.16
   Amperometric SensorChloroSense.17
Total ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
   Amperometric Titration (Low level measurement)4500-Cl E4500-Cl E.
   DPD Ferrous Titrimetric4500-Cl F4500-Cl F.
   DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
   Iodometric Electrode4500-Cl I4500-Cl I.
   On-line Chlorine AnalyzerEPA 334.0.16
   Amperometric SensorChloroSense.17
Chlorine DioxideAmperometric Titration4500-ClO2 C4500-ClO2 C.
   Amperometric Titration4500-ClO2 E.4500-ClO2 E.
   Amperometric SensorChlordioX Plus.32
OzoneIndigo Method4500-O3 B4500-O3 B.

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.131(b)(1)

ContaminantMethodologyEPA methodASTM4SM online3SM 21st edition1SM 22nd edition,28
SM 23rd edition49
Other
TTHMP&T/GC/MS524.3,9 524.4.29
HAA5LLE (diazomethane)/GC/ECD6251 B-076251 B6251 B.
   Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
   Two-Dimensional Ion Chromatography (IC) with Suppressed Conductivity DetectionThermo Fisher 557.1.47
BromateTwo-Dimensional Ion Chromatography (IC)302.0.18
   Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
   Chemically Suppressed Ion ChromatographyD 6581-08 A.
   Electrolytically Suppressed Ion ChromatographyD 6581-08 B.
ChloriteChemically Suppressed Ion ChromatographyD 6581-08 A.
   Electrolytically Suppressed Ion ChromatographyD 6581-08 B.
Chlorite—daily monitoring as prescribed in 40 CFR 141.132(b)(2)(i)(A)Amperometric Titration4500-ClO2 E4500-ClO2 E.
   Amperometric SensorChlordioX Plus.32

Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.131(c)(1)

ResidualMethodologySM 21st
edition1
SM 22nd
edition,28
SM 23rd
edition49
ASTM4Other
Free ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14.
   DPD Ferrous Titrimetric4500-Cl F4500-Cl F
   DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
   Indophenol ColorimetricHach Method 10241.34
   Syringaldazine (FACTS)4500-Cl H4500-Cl H.
   Amperometric SensorChloroSense.17
   On-line Chlorine AnalyzerEPA 334.0.16
Combined ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14.
   DPD Ferrous Titrimetric4500-Cl F4500-Cl F
   DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Total ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14.
   Low level Amperometric Titration4500-Cl E4500-Cl E.
   DPD Ferrous Titrimetric4500-Cl F4500-Cl F.
   DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
   Iodometric Electrode4500-Cl I4500-Cl I.
   Amperometric SensorChloroSense.17
   On-line Chlorine AnalyzerEPA 334.0.16
Chlorine DioxideAmperometric Method II4500-ClO2 E4500-ClO2 E.
   Amperometric SensorChlordioX Plus.32

Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.131(c)(2), If Approved by the State

ResidualMethodologyMethod
Free ChlorineTest StripsMethod D99-0035

Alternative Testing Methods for Parameters Listed at 40 CFR 141.131(d)

ParameterMethodologySM 21st edition1SM 22nd edition28SM 23rd edition49SM online3EPAOther
Total Organic Carbon (TOC)High Temperature Combustion5310 B5310 B5310 B415.3, Rev 1.2.19
   Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C415.3, Rev 1.2.19Hach Method 10267.38
   Wet Oxidation5310 D5310 D415.3, Rev 1.2.19
   Ozone OxidationHach Method 10261.37
Specific Ultraviolet Absorbance (SUVA)Calculation using DOC and UV254 data415.3, Rev 1.2.19
Dissolved Organic Carbon (DOC)High Temperature Combustion5310 B5310 B5310 B415.3, Rev 1.2.19
   Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C415.3, Rev 1.2.19
   Wet Oxidation5310 D5310 D415.3, Rev 1.2.19
Ultraviolet absorption at 254 nm (UV254)Spectrophotometry5910 B5910 B5910 B5910 B-11415.3, Rev 1.2.19

Alternative Testing Methods With MRL ≤0.0010 mg/L for Monitoring Listed at 40 CFR 141.132(b)(3)(ii)(B)

ContaminantMethodologyEPA method
BromateTwo-Dimensional Ion Chromatography (IC)302.018
   Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)55714

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.402(c)(2)

OrganismMethodologySM 20th
edition6
SM 21st
edition1
SM 22nd
edition28
SM 23rd
edition49
SM online3Other
E. coliColilert9223 B9223 B9223 B9223 B-97, B-04.
   Colisure9223 B9223 B9223 B9223 B-97, B-04.
   Colilert-189223 B9223 B9223 B9223 B9223 B-97, B-04.
   Readycult®Readycult®.20
   ColitagModified Colitag.TM13
   Chromocult®Chromocult®.21
   EC-MUG9221 F9221 F9221 F-06.
   NA-MUG9222 I.
   m-ColiBlue24 Test9222 J.
   Tecta EC/TC 3343
EnterococciMultiple-Tube Technique9230 B-04.
   Membrane Filter Techniques9230 C.
   Fluorogenic Substrate Enterococcus Test (using Enterolert)9230 D.
ColiphageTwo-Step Enrichment Presence-Absence ProcedureFast Phage.30

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.704(a)

OrganismMethodologyEPA Method
CryptosporidiumFiltration/Immunomagnetic Separation/Immunofluorescence Assay Microscopy1623.127

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.704(b)

OrganismMethodologySM 20th edition6
E. coliMembrane Filtration, Two Step9222 D/9222 G

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.852(a)(5)

OrganismMethodology categoryMethodSM 20th, 21st
editions 1 6
SM 22nd
edition28
SM 23rd
edition49
SM online3
Total ColiformsLactose Fermentation MethodsStandard Total Coliform Fermentation Technique9221 B.1, B.29221 B.1, B.2, B.3, B.49221 B.1, B.2-06.
   Presence-Absence (P-A) Coliform Test9221 D.1, D.2, D.3
   Membrane Filtration MethodsStandard Total Coliform Membrane Filter Procedure using Endo Media9222 B, C.
   Simultaneous Detection of Total Coliforms and E. coli by Dual Chromogen Membrane Filter Procedure (using mColiBlue24 medium)9222 J.
   Enzyme Substrate MethodsColilert®9223 B9223 B9223 B-04.
   Colisure®9223 B9223 B9223 B-04.
   Colilert-189223 B9223 B9223 B9223 B-04.
   Tecta EC/TC 33 43
Escherichia coliEscherichia coli Procedure (following Lactose Fermentation Methods)EC-MUG medium9221 F.19221 F.19221 F.1-06.
   Escherichia coli Partitioning Methods (following Membrane Filtration Methods)EC broth with MUG (EC-MUG)9222 H.
   NA-MUG medium9222 I.
   Simultaneous Detection of Total Coliforms and E. coli by Dual Chromogen Membrane Filter ProceduremColiBlue24 medium9222 J.
   Enzyme Substrate MethodsColilert®9223 B9223 B9223 B-04.
   Colisure®9223 B9223 B9223 B-04.
   Colilert-189223 B9223 B9223 B9223 B-04.
   Tecta EC/TC 33 43

Alternative Testing Methods for Contaminants Listed at 40 CFR 143.4(b)

ContaminantMethodologyEPA methodASTM4SM 21st
edition1
SM 22nd
edition,28
SM 23rd
edition49
SM online3
AluminumAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2.2
   Atomic Absorption; Direct3111 D3111 D.
   Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
   Inductively Coupled Plasma3120 B3120 B.
ChlorideSilver Nitrate TitrationD 512-04 B, 12 B4500-Cl B4500-Cl B
   Ion ChromatographyD 4327-114110 B4110 B.
   Potentiometric Titration4500-Cl D4500-Cl D.
ColorVisual Comparison2120 B2120 B.
Foaming AgentsMethylene Blue Active Substances (MBAS)5540 C5540 C.
IronAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2.2
   Atomic Absorption; Direct3111 B3111 B.
   Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
   Inductively Coupled Plasma3120 B3120 B.
ManganeseAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2.2
   Atomic Absorption; Direct3111 B3111 B.
   Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
   Inductively Coupled Plasma3120 B3120 B.
OdorThreshold Odor Test2150 B2150 B.
SilverAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2.2
   Atomic Absorption; Direct3111 B3111 B.
   Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
   Inductively Coupled Plasma3120 B3120 B.
SulfateIon ChromatographyD 4327-114110 B4110 B.
   Gravimetric with ignition of residue4500-SO4 2 C4500-SO4 2 C4500-SO4 2 C-97.
   Gravimetric with drying of residue4500-SO4 2 D4500-SO4 2 D4500-SO4 2 D-97.
   Turbidimetric methodD 516-07, 11, 164500-SO4 2 E4500-SO4 2 E4500-SO4 2 E-97.
   Automated methylthymol blue method4500-SO4 2 F4500-SO4 2 F4500-SO4 2 F-97.
Total Dissolved SolidsTotal Dissolved Solids Dried at 180 deg C2540 C2540 C.
ZincAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2.2
   Atomic Absorption; Direct Aspiration3111 B3111 B.
   Inductively Coupled Plasma3120 B3120 B.

1Standard Methods for the Examination of Water and Wastewater, 21st edition (2005). Available from American Public Health Association, 800 I Street, NW., Washington, DC 20001-3710.

2EPA Method 200.5, Revision 4.2. “Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry.” 2003. EPA/600/R-06/115. (Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.)

3Standard Methods Online are available at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.

4Available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 or http://astm.org. The methods listed are the only alternative versions that may be used.

5Method D99-003, Revision 3.0. “Free Chlorine Species (HOCl and OCl) by Test Strip,” November 21, 2003. Available from Industrial Test Systems, Inc., 1875 Langston St., Rock Hill, SC 29730.

6Standard Methods for the Examination of Water and Wastewater, 20th edition (1998). Available from American Public Health Association, 800 I Street, NW., Washington, DC 20001-3710.

7Method ME355.01, Revision 1.0. “Determination of Cyanide in Drinking Water by GC/MS Headspace,” May 26, 2009. Available at http://www.nemi.gov or from James Eaton, H & E Testing Laboratory, 221 State Street, Augusta, ME 04333. (207) 287-2727.

8Systea Easy (1-Reagent). “Systea Easy (1-Reagent) Nitrate Method,” February 4, 2009. Available at http://www.nemi.gov or from Systea Scientific, LLC., 900 Jorie Blvd., Suite 35, Oak Brook, IL 60523.

9EPA Method 524.3, Version 1.0. “Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry,” June 2009. EPA 815-B-09-009. Available at https://www.nemi.gov.

10Mitchell Method M5271, Revision 1.1. “Determination of Turbidity by Laser Nephelometry,” March 5, 2009. Available at http://www.nemi.gov or from Leck Mitchell, PhD, PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

11Mitchell Method M5331, Revision 1.1. “Determination of Turbidity by LED Nephelometry,” March 5, 2009. Available at http://www.nemi.gov or from Leck Mitchell, PhD, PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

12Orion Method AQ4500, Revision 1.0. “Determination of Turbidity by LED Nephelometry,” May 8, 2009. Available at http://www.nemi.gov or from Thermo Scientific, 166 Cummings Center, Beverly, MA 01915, http://www.thermo.com.

13Modified ColitagTM Method, “Modified ColitagTM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water (ATP D05-0035),” August 28, 2009. Available at http://www.nemi.gov or from CPI, International, 580 Skylane Boulevard, Santa Rosa, CA 95403.

14EPA Method 557. “Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS),” September 2009. EPA 815-B-09-012. Available at https://www.nemi.gov.

15AMI Turbiwell, “Continuous Measurement of Turbidity Using a SWAN AMI Turbiwell Turbidimeter,” August 2009. Available at http://www.nemi.gov or from Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland.

16EPA Method 334.0. “Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer,” September 2009. EPA 815-B-09-013. Available at https://www.nemi.gov.

17ChloroSense. “Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,” August 2009. Available at https://www.nemi.gov or from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018.

18EPA Method 302.0. “Determination of Bromate in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection,” September 2009. EPA 815-B-09-014. Available at https://www.nemi.gov.

19EPA 415.3, Revision 1.2. “Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water,” September 2009. EPA/600/R-09/122. Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.

20Readycult® Method, “Readycult® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichia coli in Finished Waters,” January, 2007. Version 1.1. Available from EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.

21Chromocult® Method, “Chromocult® Coliform Agar Presence/Absence Membrane Filter Test Method for Detection and Identification of Coliform Bacteria and Escherichia coli in Finished Waters,” November, 2000. Version 1.0. EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.

22Hach Company. “Hach Company SPADNS 2 (Arsenite-Free) Fluoride Method 10225—Spectrophotometric Measurement of Fluoride in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.

23Hach Company. “Hach Company TNTplusTM 835/836 Nitrate Method 10206—Spectrophotometric Measurement of Nitrate in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.

24EPA Method 525.3. “Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS),” February 2012. EPA/600/R-12/010. Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.

25EPA Method 536. “Determination of Triazine Pesticides and their Degradates in Drinking Water by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS),” October 2007. EPA 815-B-07-002. Available at the National Service Center for Environmental Publications (EPA Method 536).

26EPA Method 523. “Determination of Triazine Pesticides and their Degradates in Drinking Water by Gas Chromatography/Mass Spectrometry (GC/MS),” February 2011. EPA 815-R-11-002. Available at the National Service Center for Environmental Publications (EPA Method 523).

27EPA Method 1623.1. “Cryptosporidium and Giardia in Water by Filtration/IMS/FA,” 2012. EPA-816-R-12-001. Available at the National Service Center for Environmental Publications (www.epa.gov/nscep). Search “816R12001”.

28Standard Methods for the Examination of Water and Wastewater, 22nd edition (2012). Available from American Public Health Association, 800 I Street NW., Washington, DC 20001-3710.

29EPA Method 524.4, Version 1.0. “Measurement of Purgeable Organic Compounds in Water by Gas Chromatography/Mass Spectrometry using Nitrogen Purge Gas,” May 2013. EPA 815-R-13-002. Available at the National Service Center for Environmental Publications (EPA Method 524.4).

30Charm Sciences Inc. “Fast Phage Test Procedure. Presence/Absence for Coliphage in Ground Water with Same Day Positive Prediction”. Version 009. November 2012. 659 Andover Street, Lawrence, MA 01843. Available at www.charmsciences.com.

31Hach Company. “Hach Method 10260—Determination of Chlorinated Oxidants (Free and Total) in Water Using Disposable Planar Reagent-filled Cuvettes and Mesofluidic Channel Colorimetry,” April 2013. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

32ChlordioX Plus. “Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors,” November 2013. Available from Palintest Ltd, Jamike Avenue (Suite 100), Erlanger, KY 41018.

33Tecta EC/TC. “TechtaTMEC/TC Medium and TechtaTMInstrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water,” version 1.0, May 2014. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.

34Hach Company. “Hach Method 10241—Spectrophotometric Measurement of Free Chlorine (Cl2) in Drinking Water,” November 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

35Hach Company. “Hach Method 8026—Spectrophotometric Measurement of Copper in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

36Hach Company. “Hach Method 10272—Spectrophotometric Measurement of Copper in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

37Hach Company. “Hach Method 10261—Total Organic Carbon in Finished Drinking Water by Catalyzed Ozone Hydroxyl Radical Oxidation Infrared Analysis,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

38Hach Company. “Hach Method 10267—Spectrophotometric Measurement of Total Organic Carbon (TOC) in Finished Drinking Water,” December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

39Hach Company. “Hach Method 10258—Determination of Turbidity by 360° Nephelometry,” January 2016. Revision 1.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

40Nitrate Elimination Company, Inc. (NECi). “Method for Nitrate Reductase Nitrate-Nitrogen Analysis of Drinking Water,” February 2016. Superior Enzymes, Inc., 334 Hecla Street, Lake Linden, Michigan 49945.

41Thermo Fisher. “Thermo Fisher Scientific Drinking Water Orthophosphate Method for Thermo Scientific Gallery Discrete Analyzer,” February 2016. Revision 5. Thermo Fisher Scientific, Ratastie 2, 01620 Vantaa, Finland.

42Mitchell Method M5331, Revision 1.2. “Determination of Turbidity by LED or Laser Nephelometry,” February 2016. Available from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

43Tecta EC/TC. “TectaTM EC/TC Medium and the TectaTM Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water,” version 2.0, February 2017. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.

44Lovibond PTV 1000. “Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 1000 White Light LED Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

45Lovibond PTV 2000. “Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 2000 660-nm LED Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

46Lovibond PTV 6000. “Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 6000 Laser Turbidimeter,” December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

47Thermo Fisher. “Thermo Fisher Method 557.1: Determination of Haloacetic Acids in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection,” January 2017. Version 1.0. Available from Thermo Fisher Scientific, 490 Lakeside Dr., Sunnyvale, CA 94085 (Richard.jack@thermofisher.com).

48EPA Method 150.3. “Determination of pH in Drinking Water,” February 2017. EPA 815-B-17-001. Available at the National Service Center for Environmental Publications (EPA Method 150.3).

49Standard Methods for the Examination of Water and Wastewater, 23rd edition (2017). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

50EPA Method 900.0, Rev. 1.0. “Determination of Gross Alpha and Gross Beta in Drinking Water,” February 2018. EPA 815-B-18-002. Available at the National Service Center for Environmental Publications (EPA Method 900.0 Rev 1.0).

51Hach Company. “Hach Method 10258—Determination of Turbidity by 360° Nephelometry,” March 2018. Revision 2.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

52Hach Company. “Hach Method 8195—Determination of Turbidity by Nephelometry,” March 2018. Revision 3.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

[74 FR 38353, Aug. 3, 2009, as amended at 74 FR 57914, Nov. 10, 2009; 74 FR 63069, Dec. 2, 2009; 75 FR 32299, June 8, 2010; 76 FR 37018, June 24, 2011; 77 FR 38527, June 28, 2012; 78 FR 32565, May 31, 2013; 78 FR 37463, June 21, 2013; 79 FR 35086, June 19, 2014; 79 FR 36428, June 27, 2014; 81 FR 46844, July 19, 2016; 82 FR 34867, July 27, 2017; 83 FR 51644, Oct. 12, 2018; 83 FR 54676, Oct. 31, 2018]

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