E9-27044. Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

This action announces the Environmental Protection Agency's (EPA's) approval of alternative testing methods for use in measuring the levels of contaminants in drinking water and determining compliance with national primary drinking water regulations. The Safe Drinking Water Act (SDWA) authorizes EPA to approve the use of alternative testing methods through publication in the Federal Register. EPA is using this streamlined authority to make 25 additional methods available for analyzing drinking water samples required by regulation. This expedited approach provides public water systems, laboratories, and primacy agencies with more timely access to new measurement techniques and greater flexibility in the selection of analytical methods, thereby reducing monitoring costs while maintaining public health protection.

DATES:

This action is effective November 10, 2009.

FOR FURTHER INFORMATION CONTACT:

Safe Drinking Water Hotline: [phone] or Patricia Snyder Fair, Technical Support Center, Office of Ground Water and Drinking Water (MS 140), Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268; telephone number: [phone]; e-mail address: [e-mail].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

Public water systems are the regulated entities required to measure contaminants in drinking water samples. In addition, EPA Regions as well as States and Tribal governments with authority to administer the regulatory program for public water systems under SDWA may also measure contaminants in water samples. When EPA sets a monitoring requirement in its national primary drinking water regulations for a given contaminant, the Agency also establishes in the regulations standardized test procedures for analysis of the contaminant. This action makes alternative testing methods available for particular drinking water contaminants beyond the testing methods currently established in the regulations. EPA is providing public water systems required to test water samples with a choice of using either a test procedure already established in the existing regulations or an alternative test procedure that has been approved in this action. Categories and entities that may ultimately be affected by this action include:

Category	Examples of potentially regulated entities	NAICS 1
State, Local, & Tribal Governments	States, local and Tribal governments that analyze water samples on behalf of public water systems required to conduct such analysis; States, local and Tribal governments that themselves operate community and non-transient non-community water systems required to monitor	924110
Industry	Private operators of community and non-transient non-community water systems required to monitor	221310
Municipalities	Municipal operators of community and non-transient non-community water systems required to monitor	924110
1 North American Industry Classification System.

This table is not exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. This table lists the types of entities that EPA is now aware could potentially be affected by this action. Other types of entities not listed in the table could also be impacted. To determine whether your facility is affected by this action, you should carefully examine the applicability language at 40 CFR 141.2 (definition of public water system). If you have questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.

B. How Can I Get Copies of This Document and Other Related Information?

Docket. EPA established a docket for this action under Docket ID No. EPA-HQ-OW-2009-0707. Publicly available docket materials are available either electronically through http://www.regulations.gov or in hard copy at the Water Docket in the EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. Copyrighted materials are available only in hard copy. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is [phone], and the telephone number for the Water Docket is [phone].

Abbreviations and Acronyms Used in This Action

CFR: Code of Federal Regulations.

DOC: Dissolved Organic Carbon.

DPD: N,N-Diethyl-p-phenylenediamine.

E. coli: Escherichia coli.

EPA: Environmental Protection Agency.

HAA5: Haloacetic Acids (five); Sum of Monochloroacetic Acid, Dichloroacetic Acid, Trichloroacetic Acid, Monobromoacetic Acid, and Dibromoacetic Acid.

IC: Ion Chromatography.

IC-ESI-MS/MS: Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry.

LED: Light Emitting Diode.

mg/L: Milligrams/Liter.

MRL: Minimum Reporting Level.

NEMI: National Environmental Methods Index.

nm: Nanometers.

QC: Quality Control.

SDWA: Safe Drinking Water Act.

SUVA: Specific Ultraviolet Absorbance.

TOC: Total Organic Carbon.

UV₂₅₄: Ultraviolet Absorbance at 254 nanometers.

Table of Contents

I. General Information

A. Does This Action Apply to Me?

B. How Can I Get Copies of This Document and Other Related Information?

II. Background

A. What Is the Purpose of This Action?

B. What Is the Basis for This Action?

III. Summary of Approvals

A. Methods Developed by EPA

B. Methods Developed by Voluntary Consensus Standard Bodies (VCSB)

C. Methods Developed by Vendors

IV. Statutory and Executive Order Reviews

V. References

II. Background

A. What Is the Purpose of This Action?

In this action, EPA is approving 25 analytical methods for determining contaminant concentrations in samples collected under SDWA. Regulated parties required to sample and monitor may use either the testing methods already established in existing regulations or the alternative testing methods being approved in this action. The new methods are listed in Appendix A to Subpart C in 40 CFR 141 and on EPA's drinking water methods Web site at http://www.epa.gov/​safewater/​methods/​analyticalmethods_​expedited.html.

B. What Is the Basis for This Action?

When EPA determines that an alternative analytical method is “equally effective” (i.e., as effective as a method that has already been promulgated in the regulations), SDWA allows EPA to approve the use of the alternative method through publication in the Federal Register. (See Section 1401(1) of SDWA.) EPA is using this streamlined approval authority to make 25 additional methods available for determining contaminant concentrations in samples collected under SDWA. EPA has determined that, for each contaminant or group of contaminants listed in Section III, the additional testing methods being approved in this action are equally effective as one or more of the testing methods already established in the regulations for those contaminants. Section 1401(1) states that the newly approved methods “shall be treated as an alternative for public water systems to the quality control and testing procedures listed in the regulation.” Accordingly, this action makes these additional (and optional) 25 analytical methods legally available for meeting EPA's monitoring requirements.

This action does not add regulatory language, but does, for informational purposes, update an appendix to the regulations at 40 CFR part 141 that lists all methods approved under Section 1401(1) of SDWA. Accordingly, while this action is not a rule, it is updating CFR text and therefore is being published in the “Final Rules” section of this Federal Register.

EPA described this expedited methods approval process in an April 10, 2007, Federal Register notice (72 FR 17902) (USEPA 2007) and announced its intent to begin using the process. EPA published the first set of approvals in a June 3, 2008, Federal Register notice (73 FR 31616) (USEPA 2008) and added Appendix A to 40 CFR Part 141, Subpart C. Six additional methods were added to Appendix A to Subpart C in an August 3, 2009, Federal Register notice (74 FR 38348) (USEPA 2009a). Future approvals using this process are anticipated.

III. Summary of Approvals

EPA is approving 25 methods that are equally effective relative to methods previously promulgated in the regulations. By means of this notice, these 25 methods are added to Appendix A of 40 CFR Part 141, Subpart C.

A. Methods Developed by EPA

1. EPA Method 334.0, “Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer” (USEPA 2009b) establishes quality control (QC) criteria for on-line chlorine analyzers such that the analyzers provide data equivalent to the grab sample methodologies that are already approved in the regulations. The on-line chlorine analyzer is calibrated using aqueous standards or the results from grab samples that are collected at the same sample point as used by the analyzer. The grab samples are analyzed for chlorine using a method that is approved for drinking water compliance monitoring. The accuracy of the on-line chlorine analyzer is periodically verified (and adjustments made when necessary) based on results from grab sample analyses.

Previously approved methods for determining free and total chlorine residuals in drinking water are listed in the tables at 40 CFR 141.74(a)(2) and 40 CFR 141.131(c)(1). All of the methods are designed for grab sample analyses. The regulation at 40 CFR 141.74(a)(2) also states, “Free and total chlorine residuals may be measured continuously by adapting a specified chlorine residual method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision remain the same. Instruments used for continuous monitoring must be calibrated with a grab sample measurement at least every five days, or with a protocol approved by the State.”

Continuous monitoring instruments that use N,N-Diethyl-p-phenylene­diamine (DPD) chemistry are the only on-line chlorine analyzers that, prior to this action, met the drinking water regulatory requirement to use the same chemistry as an approved method. The instruments perform chlorine residual measurements on a frequent basis using an automated version of Standard Method 4500-Cl G (APHA 1998), which is listed in the tables at 40 CFR 141.74(a)(2) and 40 CFR 141.131(c)(1). Since the instruments use an approved method, they have the capability to provide the same accuracy and precision as the approved method (Standard Method 4500-Cl G), if they are properly installed and maintained. The performance characteristics of the instruments are periodically checked by comparing the instrumental results to grab sample measurements according to a protocol approved by the State.

EPA Method 334.0 now allows the use of on-line chlorine analyzers based on chemistry different from that of approved methods. It is a “performance based” method, which means it establishes QC criteria to bench-mark the performance of the on-line chlorine analyzer against the performance of approved grab sample methods. As long as the on-line analyzer meets the QC criteria in EPA Method 334.0, the data are deemed equivalent to data obtained using the approved grab sample methods. EPA Method 334.0 can be used with any type of on-line chlorine analyzer.

Data from 38 drinking water treatment facilities (EE&T, Inc. 2009) were used as the basis for establishing the on-line chlorine analyzer QC criteria in EPA Method 334.0. Chlorine residual measurements from on-line amperometric chlorine analyzers were compared to the results from grab sample analyses performed using either Standard Method 4500-Cl D (amperometric titration) (APHA 1998) or Standard Method 4500-Cl G (DPD colorimetric). Both Standard Methods are approved for drinking water compliance monitoring analyses and are listed in the tables at 40 CFR 141.74(a)(2) and 40 CFR 141.131(c)(1). The data from the 38 facilities demonstrate that on-line amperometric chlorine analyzers can provide data that are equivalent to approved methods.

EPA Method 334.0 requires that the analyst demonstrate that the grab sample method provides reliable data prior to using it to verify the performance of an on-line chlorine analyzer. This QC requirement is consistent with the QC requirements in the approved grab sample methods. Aqueous standards are analyzed to demonstrate the accuracy and precision of the measurements. EPA recommends that the grab sample QC requirements in EPA Method 334.0 be used with all on-line chlorine analyzers, including those that are originally approved under the provisions of 40 CFR 141.74.

A preliminary draft of EPA Method 334.0 was provided to the Association of State Drinking Water Administrators, the American Water Works Association, and the Water and Wastewater Equipment Manufacturers Association. A revised draft was reviewed by persons from two State agencies and two drinking water utilities. The final method reflects changes made in response to review comments. The public docket for this action includes the comments from these organizations and the Agency's response to comments (USEPA 2009c).

EPA has determined that EPA Method 334.0 is equally effective for measuring free and total chlorine residuals as the methods that are promulgated in the regulations at 40 CFR 141.74(a)(2) and 40 CFR 141.131(c)(1). The basis for this determination is discussed in Fair and Wendelken 2009. EPA is therefore approving use of EPA Method 334.0 for on-line analyses of free and total chlorine. A copy of the method can be accessed and downloaded directly on-line at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

2. EPA Method 302.0, “Determination of Bromate in Drinking Waters using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection” (USEPA 2009d) is a large volume (1.0 mL), two-dimensional ion chromatography (IC) method that uses suppressed conductivity detection for the determination of bromate in raw and finished drinking waters. Because this method utilizes two dissimilar IC columns it does not require second column confirmation. Detection and quantitation are accomplished in the second dimension by suppressed conductivity measurement. Bromate concentration is calculated using the integrated peak area and the external standard technique.

EPA Method 302.0 offers increased bromate specificity without the complexity of post column reactors.

The approved methods for bromate are listed at 40 CFR 141.131(b)(1). The performance characteristics of EPA Method 302.0 were compared to the characteristics of approved EPA Methods 300.1 (USEPA 2000), 317.0, Revision 2.0 (USEPA 2001), and 326.0 (USEPA 2002). EPA has determined that EPA Method 302.0 is equally effective for measuring bromate concentrations as these approved methods. EPA Method 302.0 can also meet the minimum reporting limit (MRL) requirements necessary for methods that are used to support the reduced bromate monitoring specified at 40 CFR 141.132(b)(3)(ii)(B). The basis for these determinations is discussed in Munch 2009a. EPA is therefore approving EPA Method 302.0 for the routine determination of bromate in drinking water and also allowing its use for reduced bromate monitoring. A copy of the method can be accessed and downloaded directly on-line at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

3. EPA Method 557, “Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)” (USEPA 2009e) is a direct-injection, ion chromatography, negative-ion electrospray ionization, tandem mass spectrometry (IC-ESI-MS/MS) method for the determination of nine haloacetic acids in finished drinking waters. Each method analyte is qualitatively identified via a unique mass transition, and the concentration is calculated using the integrated peak area and the internal standard technique.

Bromate may be measured concurrently with the haloacetic acids. Real time, chromatographic separation of common anions in drinking water (matrix elimination) is a key feature of this method. Acceptable method performance has been demonstrated for matrix ion concentrations of 320 milligrams/Liter (mg/L) chloride, 250 mg/L sulfate, 150 mg/L bicarbonate and 20 mg/L nitrate.

EPA Method 557 eliminates the labor intensive sample preparation steps (extraction and derivatization) that are required in the current methods that are approved for haloacetic acid determinations. It also reduces the use of solvents and potentially hazardous chemicals. The development work for this method is described in the method research summary (Zaffiro and Zimmerman 2009).

The sum of five haloacetic acids (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid) is regulated as HAA5. The approved methods for HAA5 are listed at 40 CFR 141.131(b)(1). The performance characteristics of EPA Method 557 for each of the five haloacetic acids were compared to the characteristics of approved EPA Methods 552.2 (USEPA 1995) and 552.3, Revision 1.0 (USEPA 2003) for the same compounds. EPA has determined that EPA Method 557 is equally effective for measuring HAA5 relative to approved EPA Methods 552.2 and 552.3. The basis for this determination is discussed in Munch 2009b. Therefore, EPA is approving EPA Method 557 for determining HAA5 in drinking water.

The performance characteristics of EPA Method 557 were also compared to the bromate-measurement characteristics of approved EPA Methods 300.1 (USEPA 2000), 317.0 Revision 2.0 (USEPA 2001), and 326.0 (USEPA 2002). EPA has determined that EPA Method 557 is equally effective for measuring bromate concentrations as these approved methods. EPA Method 557 can also meet the MRL requirements necessary for methods that are used to support the reduced bromate monitoring specified at 40 CFR 141.132(b)(3)(ii)(B). The basis for these determinations is discussed in Munch 2009b. EPA is therefore approving EPA Method 557 for the routine determination of bromate in drinking water and also allowing its use for reduced bromate monitoring.

A copy of EPA Method 557 can be accessed and downloaded directly on-line at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

4. EPA Method 415.3, Revision 1.2, “Determination of Total Organic Carbon and Specific UV Absorbance at 254 nanometers (nm) in Source Water and Drinking Water” (USEPA 2009f) is a slightly modified version of the currently approved EPA Method 415.3, Revision 1.1 (USEPA 2005). Revision 1.1 is listed as an approved method for determining total organic carbon (TOC), dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV₂₅₄), and specific ultraviolet absorbance (SUVA) concentrations at 40 CFR 141.131(d). Determination of UV₂₅₄ can only be done using a double beam spectrophotometer if the instrument is zeroed according to the directions in the approved method. Since many water system laboratories use single beam spectrophotometers, the method was revised to allow for their use by modifying the zeroing procedure. This modification did not result in any change in the performance of the method. Therefore, EPA finds that Method 415.3, Revision 1.2 is equally effective as Revision 1.1. Revision 1.2 also corrects some typographical errors that are present in Revision 1.1. The modifications are documented in Wimsatt 2009. EPA is approving EPA Method 415.3, Revision 1.2 for determining TOC, DOC, UV₂₅₄, and SUVA in source water and drinking water.

A copy of EPA Method 415.3, Revision 1.2 can be accessed and downloaded directly on-line at http://www.epa.gov/​nerlcwww/​ordmeth.htm.

B. Methods Developed by Voluntary Consensus Standard Bodies (VCSB)

1. Standard Methods for the Examination of Water and Wastewater. Standard Methods 9223 B-97 and 9223 B (20th and 21st Edition) can be used to detect Escherichia coli (E. coli). Approved methods for E. coli are listed at 40 CFR 141.21(f)(6). The Minimal Medium ONPG-MUG (MMO-MUG) Test is listed as an approved method for E. coli and the reference cited for the procedure is a journal article (Edberg et al. 1989). Standard Methods used the same research documented in the journal article to write Standard Method 9223 B, which is published in the 20th and 21st Edition of Standard Methods for the Analysis of Water and Wastewater (APHA 1998, 2005). The same method is also available on-line as Standard Method 9223 B-97 (APHA 1997). Since Standard Methods 9223 B (20th and 21st Edition) and 9223 B-97 are the same procedure as that documented in the Edberg et al. article, they are equally effective as the approved Edberg method for determining E. coli (Best 2009). Therefore, EPA is approving the use of Standard Methods 9223 B (20th Edition), 9223 B (21st Edition) and 9223 B-97 for determining E. coli as specified at 40 CFR 141.21(f)(6). The 20th and 21st editions can be obtained from American Public Health Association (APHA), 800 I Street, NW., Washington, DC 20001-3710. Standard Method 9223 B-97 is available at http://www.standardmethods.org.

2. ASTM International. EPA compared the most recent versions of 14 ASTM International methods to the versions of those methods cited in 40 CFR 141 and 143. Changes between the approved version and the most recent version of each method are summarized in Fair 2009. The revisions primarily involve editorial changes (i.e., updated references, reorganization, and corrections of errors). Data generated using the revised methods are comparable to data obtained using the previous versions because the chemistry, sample-handling protocols, and QC are unchanged. The new versions are equally effective relative to the version cited in the regulation (Fair 2009). Therefore, EPA is approving the use of the 14 updated ASTM methods for the contaminants and regulations listed in the following table.

The revised ASTM method for bromate and chlorite analyses (D 6581-08) is split into two techniques. Method A uses chemically suppressed ion chromatography and is the same as the approved Method D 6581-00, which is listed in the regulation at 40 CFR 141.131(b)(1); ASTM D 6581-08 A is one of the 14 methods previously discussed. Method B uses electrolytically suppressed ion chromatography and represents a new method. EPA compared the bromate and chlorite performance data for Method B to the data in the approved Method D 6581-00 and determined that Method B is equally effective as the currently approved method (Fair 2009). Therefore, EPA is approving ASTM D 6581-08 B for the determination of bromate and chlorite in routine drinking water compliance samples.

The ASTM methods that are approved in this action are listed in the following table:

ASTM method	Contaminant	Regulation
D511-09 A (ASTM International 2009a)	Calcium	40 CFR 141.23(k)(1).
	Magnesium	40 CFR 141.23(k)(1).
D511-09 B (ASTM International 2009a)	Calcium	40 CFR 141.23(k)(1).
	Magnesium	40 CFR 141.23(k)(1).
D1688-07 A (ASTM International 2009b)	Copper	40 CFR 141.23(k)(1).
D1688-07 C (ASTM International 2009b)	Copper	40 CFR 141.23(k)(1).
D2972-08 B (ASTM International 2009c)	Arsenic	40 CFR 141.23(k)(1).
D2972-08 C (ASTM International 2009c)	Arsenic	40 CFR 141.23(k)(1).
D3559-08 D (ASTM International 2009d)	Lead	40 CFR 141.23(k)(1).
D3645-08 B (ASTM International 2009e)	Beryllium	40 CFR 141.23(k)(1).
D3697-07 (ASTM International 2009f)	Antimony	40 CFR 141.23(k)(1).
D3859-08 A (ASTM International 2009g)	Selenium	40 CFR 141.23(k)(1).
D3859-08 B (ASTM International 2009g)	Selenium	40 CFR 141.23(k)(1).
D1253-08 (ASTM International 2009h)	Free Chlorine	40 CFR 141.74(a)(2).
		40 CFR 141.131(c)(1)
	Total Chlorine	40 CFR 141.74(a)(2).
		40 CFR 141.131(c)(1).
	Combined Chlorine	40 CFR 141.131(c)(1).
D516-07 (ASTM International 2009i)	Sulfate	40 CFR 143.4(b).
D6581-08 A (ASTM International 2009j)	Bromate	40 CFR 141.131(b)(1).
	Chlorite	40 CFR 141.131(b)(1).
D6581-08 B (ASTM International 2009j)	Bromate	40 CFR 141.131(b)(1).
	Chlorite	40 CFR 141.131(b)(1).

The 15 ASTM methods are available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 or http://www.astm.org.

C. Methods Developed by Vendors

1. AMI Turbiwell Method (SWAN Analytische Instrumente AG 2009a) uses light emitting diode (LED) nephelometry to continuously measure turbidity in drinking water. The turbidimeter utilizes a non-contact light source design to avoid fouling of optical surfaces. The LED has an emission range of 415 nm to 780 nm with a peak spectral radiance of 562nm. The light beam from the emission LED impinges the water surface and is refracted. The detector measures the scattered light at an angle of 90°. A light barrier avoids measurement errors due to light reflections. The instrument is equipped with an internal data logger, or the data can be downloaded to a personal computer or central data system with appropriate computer software.

The approved methods for turbidity are listed at 40 CFR 141.74(a)(1). The performance characteristics of the AMI Turbiwell turbidimeter were compared to the performance characteristics of approved EPA Method 180.1 (USEPA 1993). The validation study report (SWAN Analytische Instrumente AG 2009b) summarizes the results obtained from the turbidimeters placed in series at three different public water systems. One water system used ground water and the other two plants used surface water sources. Measurements included at least one filter backwash at each of the surface water plants.

EPA has determined that the AMI Turbiwell Method is equally effective as approved EPA Method 180.1. The basis for this determination is discussed in the validation study report (SWAN Analytische Instrumente AG 2009b). Therefore, EPA is approving the AMI Turbiwell Method for determining turbidity in drinking water. A copy of the method can be downloaded from the National Environmental Methods Index (NEMI) at http://www.nemi.gov or obtained by contacting Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland.

2. ChloroSense (Palintest Ltd 2009a) is an electrochemical sensor method that measures free and total chlorine using disposable sensors. Free and combined available chlorine react with proprietary reagents on the sensor to create intermediate reaction products. These products are then detected electrochemically. The current that flows in each case is proportional to the amount of free available chlorine or total available chlorine in the sample. The sensors are pre-calibrated, and free and total chlorine concentrations are displayed upon completion of the analysis.

Approved methods for determining free and total chlorine residuals in drinking water are listed in the tables at 40 CFR 141.74(a)(2) and 40 CFR 141.131(c)(1). The performance characteristics of ChloroSense were compared to the performance characteristics of approved Standard Methods 4500-Cl D (amperometric titration)(APHA 1998) and 4500-Cl G (DPD colorimetric)(APHA 1998). A variety of samples, including drinking water samples from both surface and ground water sources, were fortified with known chlorine concentrations and then analyzed by each method. The results are summarized in the validation study report (Palintest Ltd 2009b).

EPA has determined that the ChloroSense Method is equally effective as approved Standard Methods 4500-Cl D and 4500-Cl G. The basis for this determination is discussed in the validation study report (Palintest Ltd 2009b). Therefore, EPA is approving the ChloroSense Method for determining free and total chlorine residuals in drinking water. A copy of the method can be downloaded from NEMI at http://www.nemi.gov or obtained by contacting Palintest Ltd, 21 Kenton Lands Road, P.O. Box 18395, Erlanger, KY 41018.

3. Modified Colitag^TM (CPI International 2009). Colitag^TM (CPI International 2001) is a presence/absence method approved for use under the Total Coliform Rule. It uses enzymatic cleavage of a chromogenic substance to detect total coliforms and enzymatic cleavage of a fluorogenic substance to detect E. coli in a 100 mL sample of drinking water. Detection of total coliforms and E. coli are performed simultaneously by this method. Colitag^TM may also be used in a most-probable-number format provided that the sum of all individual portions of the sample total 100 mL. Modified Colitag^TM has a different formulation from the originally approved Colitag^TM. The purpose of the formula change is to achieve greater selectivity for total coliforms and E. coli. Additionally, the Modified Colitag^TM provides flexibility in the incubation period (16 to 48 hours), while the approved Colitag^TM requires a 24 hour incubation time.

Approved methods for total coliforms are listed at 40 CFR 141.21(f)(3) and approved methods for E. coli are listed at 40 CFR 141.21(f)(6). The performance characteristics of Modified Colitag^TM were compared to Standard Methods 9221 B (LTB/BGLB) for total coliforms and 9222 G (LTB/EC-MUG) for E. coli (APHA 1998). The comparison study involved analyses of twenty replicate drinking water samples that were inoculated with very low densities of chlorine stressed total coliforms or E. coli obtained from ten geographically dispersed waste waters. Method specificity was evaluated using 100 positive and 100 negative cultures as determined from analyses by the reference methods.

EPA has determined that the Modified Colitag^TM Method is equally effective as approved Standard Methods 9221 B for total coliforms and 9222 G for E. coli, which are already promulgated in the regulations at 40 CFR 141.21(f)(3) and 40 CFR 141.21(f)(6), respectively. The basis for this determination is discussed in the study report (USEPA 2009g). Therefore, EPA is approving the Modified Colitag^TM Method for determining total coliforms and E. coli in drinking water. A copy of the method can be downloaded from NEMI at http://www.nemi.gov or obtained by contacting CPI International, 580 Skylane Boulevard, Santa Rosa, CA 95403.

IV. Statutory and Executive Order Reviews

As noted in Section II, under the terms of SDWA Section 1401(1), this streamlined method approval action is not a rule. Accordingly, the Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, does not apply because this action is not a rule for purposes of 5 U.S.C. 804(3). Similarly, this action is not subject to the Regulatory Flexibility Act because it is not subject to notice and comment requirements under the Administrative Procedure Act or any other statute. In addition, because this approval action is not a rule but simply makes alternative (optional) testing methods available for monitoring under SDWA, EPA has concluded that other statutes and executive orders generally applicable to rulemaking do not apply to this approval action.

V. References

American Public Health Association (APHA). 1997. Standard Method 9223-97. Enzyme Substrate Coliform Test. Approved by Standard Methods Committee 1997. Standard Methods Online. (Available at http://www.standardmethods.org.)

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

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

ASTM International. 2009a. ASTM D 511-09. Standard Test Methods for Calcium and Magnesium in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009b. ASTM D 1688-07. Standard Test Methods for Copper in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009c. ASTM D 2972-08. Standard Test Methods for Arsenic in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009d. ASTM D 3559-08. Standard Test Methods for Lead in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009e. ASTM D 3645-08. Standard Test Methods for Beryllium in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009f. ASTM D 3697-07. Standard Test Methods for Antimony in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009g. ASTM D 3859-08. Standard Test Methods for Selenium in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009h. ASTM D 1253-08. Standard Test Method for Residual Chlorine in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009i. ASTM D 516-07. Standard Test Method for Sulfate Ion in Water. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

ASTM International. 2009j. ASTM D 6581-08. Standard Test Methods for Bromate, Bromide, Chlorate, and Chlorite in Drinking Water by Suppressed Ion Chromatography. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (Available at http://www.astm.org.)

Best, J. 2009. Memo to the record describing basis for expedited approval of Standard Methods 9223 B (20th Edition), 9223 B (21st Edition) and 9223 B-97 for determining E. coli as specified at 40 CFR 141.21(f)(6). August 31, 2009.

CPI International. 2001. Colitag^TM Test. Colitag^TM Product as a Test for Detection and Identification of Coliforms and Escherichia coli Bacteria in Drinking Water and Source Water as Required in National Primary Drinking Water Regulations. August 2001. 580 Skylane Boulevard, Santa Rosa, CA 95403.

CPI International. 2009. Modified Colitag^TM Method. Modified Colitag^TM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water (ATP D05-0035). August 28, 2009. 5580 Skylane Boulevard, Santa Rosa, CA 95403.

Edberg, S.C. et al. 1989. “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.” Applied Environmental Microbiology, Vol. 55, pp. 1003-1008, April 1989.

Environmental Engineering & Technology, Inc. (EE&T, Inc.). Memorandum No. 4 to AWWA. Final Analysis of Online Amperometric Data. EE&T Project No. 5318, February 27, 2009. EE&T, Inc., 712 Gum Rock Court, Newport News, VA 23606.

Fair, P. 2009. Memo to the record describing basis for approval of updated ASTM methods. September 30, 2009.

Fair, P. and Wendelken, S. 2009. Memo to the record describing basis for expedited approval of EPA Method 334.0. September 30, 2009.

Munch, D. 2009a. Memo to the record describing basis for expedited approval of EPA Method 302.0 for bromate. September 30, 2009.

Munch, D. 2009b. Memo to the record describing basis for expedited approval of EPA Method 557 for HAA5 and bromate. October 6, 2009.

Palintest Ltd. 2009a. ChloroSense Method, Rev. 1.0. Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense, August 10, 2009, Palintest Ltd, 21 Kenton Lands Road, PO Box 18395, Erlanger, KY 41018. (Available at http://www.nemi.gov.)

Palintest Ltd. 2009b. ATP Evaluation of Palintest ChloroSense for the Measurement of Free and Total Chlorine, August 10, 2009. Palintest Ltd, 21 Kenton Lands Road, PO Box 18395, Erlanger, KY 41018.

SWAN Analytische Instrumente AG. 2009a. AMI Turbiwell Method, Rev. 1.0. Continuous Measurement of Turbidity Using a SWAN AMI Turbiwell Turbidimeter, August 10, 2009, Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland. (Available at http://www.nemi.gov.)

SWAN Analytische Instrumente AG. 2009b. ATP Evaluation of the SWAN AMI Turbiwell Turbidimeter for Measurement of Turbidity, August 10, 2009. Studbachstrasse 13, CH-8340 Hinwil, Switzerland.

USEPA. 1993. EPA Method 180.1, Revision 2.0, “Determination of Turbidity by Nephelometry” in Methods for the Determination of Inorganic Substances in Environmental Samples, EPA/600/R-93/100. (Available at http://www.nemi.gov.)

USEPA. 1995. EPA Method 552.2, “Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection” in Methods for the Determination of Organic Compounds in Drinking Water, Supplement III, EPA/600/R-95-131, August 1995. (Available at http://www.nemi.gov.)

USEPA. 2000. EPA Method 300.1, “Determination of Inorganic Anions in Drinking Water by Ion Chromatography” in Methods for the Determination of Organic and Inorganic Compounds in Drinking Water, Volume 1, EPA 815-R-00-014. (Available at http://www.epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2001. EPA Method 317.0, Revision 2.0, Determination of Inorganic Oxyhalide Disinfection By-Products in Drinking Water Using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis, EPA 815-B-01-001, July 2001. (Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2002. EPA Method 326.0, Determination of Inorganic Oxyhalide Disinfection By-Products in Drinking Water Using Ion Chromatography Incorporating the Addition of a Suppressor Acidified Postcolumn Reagent for Trace Bromate Analysis, EPA 815-R-03-007, June 2002. (Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2003. 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, EPA 815-B-03-002, July 2003. (Available at http://www.epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html).

USEPA. 2005. EPA Method 415.0, Revision 1.1. Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water. EPA/600/R-05/055, February 2005. (Available at http://www.epa.gov/​nerlcwww/​ordmeth.htm.)

USEPA. 2007. Expedited Approval of Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures. 72 FR 17902. April 10, 2007.

USEPA. 2008. Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures. 73 FR 31616. June 3, 2008.

USEPA. 2009a. Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures. 74 FR 38348. August 3, 2009.

USEPA. 2009b. EPA Method 334.0. Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer, EPA 815-B-09-013. September 2009. (Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2009c. Response to Comments Document for Review of EPA Method 334.0. September 30, 2009.

USEPA. 2009d. EPA Method 302.0. Determination of Bromate in Drinking Waters using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection, EPA 815-B-09-014. September 2009. (Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2009e. EPA Method 557. Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS), EPA 815-B-09-012, August 2009. (Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.)

USEPA. 2009f. EPA Method 415.0, Revision 1.2. Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water. EPA/600/R-09/122, September 2009. (Available at http://www.epa.gov/​nerlcwww/​ordmeth.htm.)

USEPA. 2009g. ATP Study Report of Modified Colitag^TM, ATP Case No. D05-0035, September 21, 2009.

Wimsatt, J. 2009. Memo to the record describing changes to EPA Method 415.3, Revision 1.1 that are incorporated into Revision 1.2. September 30, 2009.

Zaffiro, A.D. and Zimmerman, M. 2009. EPA Method 557 Research Summary, Shaw Environmental Inc., Cincinnati OH. March 2009.

List of Subjects in 40 CFR Part 141

• Chemicals
• Environmental protection
• Indians—lands
• Intergovernmental relations
• Radiation protection
• Reporting and recordkeeping requirements
• Water supply

Dated: October 29, 2009.

Peter S. Silva,

Assistant Administrator, Office of Water.

For the reasons stated in the preamble, 40 CFR part 141 is amended as follows:

PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS

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

Authority: 42 U.S.C. 300f, 300g-l, 300j-4, and 300j-9.

2. Appendix A to subpart C of part 141 is amended as follows:

a. By revising the entry in the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.21(f)(3).”

b. By adding the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.21(f)(6)” after the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.21(f)(3).”

c. By revising the entries for “Antimony,” “Arsenic,” “Beryllium,” “Calcium,” “Copper,” “Lead,” “Magnesium,” and “Selenium” in the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.23(k)(1).”

d. By revising the entry for “Turbidity” in the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.74(a)(1).”

e. By revising the entries for “Free Chlorine” and “Total Chlorine” in the table entitled “Alternative testing methods for disinfectant residuals listed at 40 CFR 141.74(a)(2).”

f. By revising the entry for “HAA5” and adding the entries for “Bromate” and “Chlorite” after the entry for “HAA5” in the table entitled “Alternative testing methods for contaminants listed at 40 CFR 141.131(b)(1).”

g. By revising the entries for “Free Chlorine,” “Combined Chlorine” and “Total Chlorine” in the table entitled “Alternative testing methods for disinfectant residuals listed at 40 CFR 141.131(c)(1).”

h. By revising all the entries in the table entitled “Alternative testing methods for parameters listed at 40 CFR 141.131(d).”

i. By adding the table entitled “Alternative testing methods with MRL ≤ 0.0010 mg/L for monitoring listed at 40 CFR 141.132(b)(3)(ii)(B)” after the table entitled “Alternative testing methods for parameters listed at 40 CFR 141.131(d).”

j. By revising the entry for “Sulfate” in the table entitled “Alternative testing methods for contaminants listed at 40 CFR 143.4(b)” and,

k. By adding footnotes 13 through 19 to the table.

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

* * * * *

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

Organism	Methodology	SM 21st edition 1	Other
Total Coliforms	Total Coliform Fermentation Technique	9221 A, B
	Total Coliform Membrane Filter Technique	9222 A, B, C
	Presence-Absence (P-A) Coliform Test	9221 D
	ONPG-MUG Test	9223
	Colitag TM		Modified Colitag TM13

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

Organism	Methodology	SM 20th edition 6	SM 21st edition 1	SM online 3	Other
E. coli	ONPG-MUG Test	9223 B	9223 B	9223 B-97
					Modified Colitag TM13

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

Contaminant	Methodology	EPA method	SM 21st edition 1	SM online 3	ASTM 4	Other
*         *         *         *         *         *         *
Antimony	Hydride-Atomic Absorption				D 3697-07
	Atomic Absorption; Furnace		3113 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.2
Arsenic	Atomic Absorption; Furnace		3113 B		D 2972-08 C
	Hydride Atomic Absorption		3114 B		D 2972-08 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *         *
Beryllium	Inductively Coupled Plasma		3120 B
	Atomic Absorption; Furnace		3113 B		D 3645-08 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *         *
Calcium	EDTA titrimetric		3500-Ca B		D 511-09 A
	Atomic Absorption; Direct Aspiration		3111 B		D 511-09 B
	Inductively Coupled Plasma		3120 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *         *
Copper	Atomic Absorption; Furnace		3113 B		D 1688-07 C
	Atomic Absorption; Direct Aspiration		3111 B		D 1688-07 A
	Inductively Coupled Plasma		3120 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *         *
Lead	Atomic Absorption; Furnace		3113 B		D 3559-08 D
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
Magnesium	Atomic Absorption		3111 B		D 511-09 B
	Inductively Coupled Plasma		3120 B
	Complexation Titrimetric Methods		3500-Mg B		D 511-09 A
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *         *
Selenium	Hydride-Atomic Absorption		3114 B		D 3859-08 A
	Atomic Absorption; Furnace		3113 B		D 3859-08 B
	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.2.
*         *         *         *         *         *

* * * * *

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

Organism	Methodology	SM 21st edition 1	Other
*         *         *         *         *         *
Turbidity	Nephelometric Method	2130 B
	Laser Nephelometry (on-line)		Mitchell M5271 10
	LED Nephelometry (on-line)		Mitchell M5331 11
	LED Nephelometry (on-line)		AMI Turbiwell 15
	LED Nephelometry (portable)		Orion AQ4500 12

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

Residual	Methodology	SM 21st edition 1	ASTM 4	Other
Free Chlorine	Amperometric Titration	4500-Cl D	D 1253-08
	DPD Ferrous Titrimetric	4500-Cl F
	DPD Colorimetric	4500-Cl G
	Syringaldazine (FACTS)	4500-Cl H
	On-line Chlorine Analyzer			EPA 334.0 16
	Amperometric Sensor			ChloroSense 17
Total Chlorine	Amperometric Titration	4500-Cl D	D 1253-08
	Amperometric Titration (Low level measurement)	4500-Cl E
	DPD Ferrous Titrimetric	4500-Cl F
	DPD Colorimetric	4500-Cl G
	Iodometric Electrode	4500-Cl I
	On-line Chlorine Analyzer			EPA 334.0 16
	Amperometric Sensor			ChloroSense 17
*         *         *         *         *         *

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

Contaminant	Methodology	EPA method	ASTM 4	SM 21st edition 1
*         *         *         *         *         *
HAA5	LLE (diazomethane)/GC/ECD			6251 B
*         *         *         *         *         *
	Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)	557 14
Bromate	Two-Dimensional Ion Chromatography (IC)	302.0 18
	Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)	557 14
	Chemically Suppressed Ion Chromatography		D 6581-08 A
	Electrolytically Suppressed Ion Chromatography		D 6581-08 B
Chlorite	Chemically Suppressed Ion Chromatography		D 6581-08 A
	Electrolytically Suppressed Ion Chromatography		D 6581-08 B

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

Residual	Methodology	SM 21st edition 1	ASTM 4	Other
Free Chlorine	Amperometric Titration	4500-Cl D	D 1253-08
	DPD Ferrous Titrimetric	4500-Cl F
	DPD Colorimetric	4500-Cl G
	Syringaldazine (FACTS)	4500-Cl H
	Amperometric Sensor			ChloroSense 17
	On-line Chlorine Analyzer			EPA 334.0 16
Combined Chlorine	Amperometric Titration	4500-Cl D	D 1253-08
	DPD Ferrous Titrimetric	4500-Cl F
	DPD Colorimetric	4500-Cl G
Total Chlorine	Amperometric Titration	4500-Cl D	D 1253-08
	Low level Amperometric Titration	4500-Cl E
	DPD Ferrous Titrimetric	4500-Cl F
	DPD Colorimetric	4500-Cl G
	Iodometric Electrode	4500-Cl I
	Amperometric Sensor			ChloroSense 17
	On-line Chlorine Analyzer			EPA 334.0 16

* * * * *

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

Parameter	Methodology	SM 21st edition 1	EPA
Total Organic Carbon (TOC)	High Temperature Combustion	5310 B	415.3, Rev 1.2 19
	Persulfate-Ultraviolet or Heated Persulfate Oxidation	5310 C	415.3, Rev 1.2
	Wet Oxidation	5310 D	415.3, Rev 1.2
Specific Ultraviolet Absorbance (SUVA)	Calculation using DOC and UV254 data		415.3, Rev 1.2
Dissolved Organic Carbon (DOC)	High Temperature Combustion	5310 B	415.3, Rev 1.2
	Persulfate-Ultraviolet or Heated Persulfate Oxidation	5310 C	415.3, Rev 1.2
	Wet Oxidation	5310 D	415.3, Rev 1.2
Ultraviolet absorption at 254 nm (UV254)	Spectrophotometry	5910 B	415.3, Rev 1.2

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

Contaminant	Methodology	EPA method
Bromate	Two-Dimensional Ion Chromatography (IC)	302.0 18
	Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)	557 14

* * * * *

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

Contaminant	Methodology	EPA Method	ASTM 4	SM 21st edition 1	SM Online 3
*         *         *         *         *         *
Sulfate	Ion Chromatography			4110 B
	Gravimetric with ignition of residue			4500-SO4−2 C	4500-SO4−2 C-97
	Gravimetric with drying of residue			4500-SO4−2 D	4500-SO4− D-97
	Turbidimetric method		D 516-07	4500-SO4−2 E	4500-SO4−2 E-97
	Automated methylthymol blue method			4500-SO4−2 F	4500-SO4−2 F-97
*         *         *         *         *         *

¹ Standard 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.

² EPA 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/​nerlcwww/​ordmeth.htm.)

³ 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.

⁴ Available 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.

* * * * *

⁶ Standard 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.

* * * * *

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

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

¹² Orion 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.

¹³ Modified Colitag^TM Method, “Modified Colitag^TM 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.

¹⁴ EPA Method 557. “Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS),” August 2009. EPA 815-B-09-012. Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

¹⁵ AMI 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.

¹⁶ EPA Method 334.0. “Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer,” August 2009. EPA 815-B-09-013. Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

¹⁷ ChloroSense. “Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,” September 2009. Available at http://www.nemi.gov or from Palintest Ltd, 21 Kenton Lands Road, PO Box 18395, Erlanger, KY 41018.

¹⁸ EPA Method 302.0. “Determination of Bromate in Drinking Waters using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection,” September 2009. EPA 815-B-09-014. Available at http://epa.gov/​safewater/​methods/​analyticalmethods_​ogwdw.html.

¹⁹ EPA 415.3, Revision 1.2. “Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water,” August 2009. EPA/600/R-09/122. Available at http://www.epa.gov/​nerlcwww/​ordmeth.htm.