![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20090509082321im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures
PDF Version (18 pp, 1164K, About PDF) [Federal Register: June 3, 2008 (Volume 73, Number 107)] [Rules and Regulations] [Page 31616-31633] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr03jn08-9] ----------------------------------------------------------------------- ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 141 [EPA-HQ-OW-2006-0958; FRL-8573-7] 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 99 additional methods available for analyzing drinking water samples required by regulation. This expedited approach provides public water systems, laboratories, and primary 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 June 3, 2008. FOR FURTHER INFORMATION CONTACT: 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: (513) 569-7937; e-mail address: fair.pat@epa.gov. 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. Starting today, public water systems required to test water samples have 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 (or that is approved in similar future actions). Categories and [[Page 31617]] 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 924110 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. Industry........................................ Private operators of community and non-transient 221310 non-community water systems required to monitor. Municipalities.................................. Municipal operators of community and non- 924110 transient non-community water systems required to monitor. ---------------------------------------------------------------------------------------------------------------- \1\ North American Industry Classification System. This table is not intended to be 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? 1. Docket. EPA has established a docket for this action under Docket ID No. EPA-HQ-OW-2006-0958. 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 (202) 566-1744, and the telephone number for the Water Docket is (202) 566-2426. 2. Electronic Access. You may access this Federal Register document electronically through the EPA Internet under the Federal Register listings at http://www.epa.gov/fedrgstr/. Abbreviations and Acronyms Used in This Action APHA: American Public Health Association ASDWA: Association of State Drinking Water Administrators ATP: Alternate Test Procedure AVICP-AES: Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry CFR: Code of Federal Regulations EPA: Environmental Protection Agency FEM: Forum on Environmental Measurements GWR: Ground Water Rule HPLC: High-Performance Liquid Chromatography ITS: Industrial Test Systems, Inc. LT2ESWTR: Long Term 2 Enhanced Surface Water Treatment Rule NEMI: National Environmental Method Index SDWA: Safe Drinking Water Act VCSB: Voluntary Consensus Standard Body 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? C. Solicited Comments D. Additional Comments III. Summary of Approvals A. Methods from Voluntary Consensus Standard Bodies (VCSB) B. Methods developed by EPA 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 99 analytical methods for determining contaminant concentrations in samples collected under SDWA. Regulated parties who are required to sample and monitor may do so by using 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 www.epa.gov/ safewater/methods/expedited.html. A hard copy of the list of methods is also available by calling the Safe Drinking Water Hotline at (800) 426- 4791. 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 today to make 99 additional methods available for determining contaminant concentrations in samples collected under SDWA. EPA has determined that, for each contaminant or group of contaminants listed below, the additional testing methods being approved in this action are equally as 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) 99 analytical methods legally available for meeting monitoring requirements. This action does not add regulatory language, but does, for informational purposes, add an appendix to the regulations at 40 CFR part 141 that lists the newly approved methods. Accordingly, while this action is not a rule, it is adding 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 2007a) and announced its intent to begin using the process. EPA also solicited public comments on some of the implementation aspects of the process. EPA received comments from seven States, two water systems, the Association of Public Health Laboratories, the Association of State Drinking Water Administrators (ASDWA), American Water Works Association, a commercial vendor, a manufacturing company, and an anonymous person. The comments were very supportive of the new approval process. A summary of the most significant public comments is [[Page 31618]] presented in Section II.C and D. The public docket for this action includes the Agency's complete response to comments (USEPA, 2008). C. Solicited Comments 1. Location of the comprehensive list of methods approved under the expedited process. In the April 10, 2007, Federal Register notice (72 FR 17902) (USEPA 2007a), EPA suggested three potential places for listing all of the alternative methods that EPA has approved using this expedited process. Public comments supported the use of all three approaches (i.e., publishing as an appendix in the Code of Federal Regulations (CFR), posting on the EPA Web site, and making available from a designated Agency contact). The National Environmental Method Index (NEMI) was mentioned as an additional mechanism for making the list available. EPA is providing the list in all of the suggested locations. First, this action adds Appendix A to Subpart C of Part 141 (titled ``Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act'') to the CFR. The appendix provides the States with a reference they can cite in their regulations, as was requested by ASDWA and others. EPA intends to update the appendix each time additional methods are approved using the expedited process. The EPA drinking water methods Web site contains a new page that focuses on the expedited methods approval process www.epa.gov/ safewater/methods/expedited.html. The page contains a link that allows users to download a copy of the list of methods approved using this process. The revision date and reference to the CFR citation are included on the list. Hard copies of the list are also available from the Safe Drinking Water Hotline. EPA will continue to provide the managers of NEMI with the information needed to incorporate newly approved methods into the NEMI database. EPA methods are available for download from the NEMI Web site (http://www.nemi.gov) and information is provided on the sources of any methods that must be purchased. 2. Type of information included with expedited approval decisions published in the Federal Register. Almost everyone who commented requested that EPA provide information beyond a listing of methods and the regulations to which the methods apply. A summary of the method, the method citation, and the source for obtaining the method were of greatest interest. EPA is including the method citation and source in the footnote section of the table that lists methods approved under the expedited process. This format ensures that the information is always available with the list. EPA plans to provide a summary of each new method as part of the discussion in the Federal Register that approves the method, unless the method is an updated version of a previously approved method (e.g., published in an earlier edition of Standard Methods for the Analysis of Water and Wastewater). In the latter case, the original method will have already been described. The approvals are effective on the date of publication in the Federal Register. EPA intends to provide additional information concerning the method approval as part of the supporting material in the docket for each action that approves additional, alternative methods using the expedited process. A copy of each method being approved will be included in the docket for the action. Additional information will generally include: • The Alternative Test Procedures (ATP) summary report for methods evaluated under the ATP process; • EPA method development report for EPA methods (summary of experiments conducted during method development); • A description of changes to the original method for modified methods; and • Rationale for approval including: • Summary of the performance characteristics that relate to approval; • Detection limits and/or minimum reporting levels (MRLs) when they are a regulatory requirement; and • Benefits provided by the new method. In some cases, EPA may have already promulgated more than one analytical method for a particular contaminant. In considering a new method for approval, EPA may find that the new method has performance characteristics that fall within the range of more than one of the existing promulgated methods. In those cases, EPA may approve the new method under the expedited process by comparing its effectiveness to the group of existing promulgated methods rather than by reference to a single existing method. 3. Amending regulatory text to describe where the list of methods approved using the expedited process is found. Most commenters indicated it would be helpful if the methods tables in the regulations include a reference to the list of additional, alternative methods approved under the expedited process. The commenters provided mixed reactions to adding the same information at 40 CFR 141.27. EPA is considering adding the requested references to the CFR text as part of a future regulatory action. Some commenters wanted EPA to publish a comprehensive list of all approved drinking water methods. A few suggested that EPA incorporate the alternative methods approved under the expedited method approval process into the regulations when the methods tables are updated. EPA understands the desire to have all methods listed together. As a result, EPA is revising the drinking water methods Web site (http:// www.epa.gov/safewater/methods/methods.html) to address this request. The user will be able to download comprehensive lists organized by regulation/monitoring requirement (e.g., Ground Water Rule, Unregulated Contaminant Monitoring Rule, Organic Contaminant Monitoring, etc.). Each list will include the drinking water methods authorized in the regulation and the alternative methods approved via the expedited process. The revision date and CFR citations will be included on each list. EPA believes that making the comprehensive lists available on the Internet provides more timely access to the information in the requested format than amending the methods tables in the regulations would provide. 4. Format of the table that lists methods approved using the expedited approval process. Most commenters indicated the table format presented in the April 10, 2007, Federal Register notice (72 FR 17902) (USEPA 2007a) is acceptable. One commenter suggested that the contaminants be listed alphabetically in the first column of the table in order to be consistent with the methods tables in the regulation, while also providing a listing of all methods for a single contaminant together. The commenter also requested that the table be completely updated each time new approvals are made instead of appending new approvals to the end of the table. EPA is incorporating several of the suggestions into the final table format. The table is organized by contaminant in order to improve stakeholder access to the information. The table is divided into sections so that the format mimics the methods tables in 40 CFR 141 and 143. In future expedited method approval actions, EPA will also incorporate new methods into the table rather than appending them onto the end in order to maintain the format. Appendix A to Subpart C of Part 141 contains the same type of information as was presented in the April 10, 2007, notice. Additional information regarding the newly approved, [[Page 31619]] alternative methods is included in the Federal Register preamble and in the docket as part of the background information concerning the approvals. In the future, if EPA withdraws approval for a method that was approved via the expedited process, the Agency intends to update the table at Appendix A to Subpart C of Part 141 to reflect both the approval and withdrawal dates for the method in question. 5. State implementation of methods approved under the expedited process. States' approaches to allowing use of methods approved under the expedited process will vary. Some States will need to incorporate the expedited process into their regulations while other States may allow the use of the methods as soon as laboratories become certified to use them. Some State certification programs are able to adopt methods as soon as EPA approves them. This variability in implementation approaches means some States will be able to adopt methods approved under the expedited process more quickly than other States. Although this variability was mentioned in the comments, this situation is not unique to methods approved using the expedited process; it is also a factor for methods approved via rulemaking. One approach that EPA is using to assist States is to add an appendix in the CFR that lists all alternative methods approved using the expedited process. States can cite this appendix (Appendix A to Subpart C in 40 CFR 141) when they update their regulations. EPA is also making a copy of the appendix available on a Web page www.epa.gov/safewater/methods/expedited.html. Some States may be able to cite the URL as a source for alternative methods approved under the expedited process. Some States requested early access to information about methods that are under consideration for approval in order to provide more time to adopt EPA-approved methods. EPA will consider this request as it implements the expedited process. Early sharing of information with States would give them additional time to prepare for adopting new analytical methods after they are published in the Federal Register. State adoption of alternative methods approved under the expedited process is optional. States may choose to allow only a more limited set of methods to be used for compliance. States that choose to allow the alternative methods approved through this expedited process will be consistent with the requirement that States must have programs at least as stringent as the Federal drinking water program in order to have primary enforcement responsibility for the drinking water program. When the regulation requires that the laboratory be certified to perform analyses of samples for a specific contaminant, then this requirement extends to the use of methods approved through the expedited process. This means the States that choose to allow these alternative methods will need to develop certification criteria, train auditors, and evaluate laboratory capabilities for using the newly approved methods. EPA expects that State certification programs will incorporate methods approved using the expedited process into their programs in the same manner as methods that are approved using rulemaking. If the method is an updated version or a slight modification of a previously approved method, then an abbreviated certification process may be applicable. The approval of methods, whether under rulemaking or the expedited approach, presents similar challenges to the Agency and the States. The approval decisions must be conveyed to the appropriate persons within the States. EPA plans to disseminate information concerning future method approvals using several approaches. A copy of the Federal Register action will be sent to the State drinking water certification and program offices. The Safe Drinking Water Hotline will have information concerning the approvals and information will be posted on EPA's drinking water methods Web page. Withdrawal of method approval is a rare event under the regulatory process and EPA expects its occurrence under the expedited process will also be very limited. Methods will generally be withdrawn using the same process as was used for their approval. Methods approved via the expedited process will generally be withdrawn using the expedited process; methods approved under rulemaking will be withdrawn using rulemaking. Soliciting public comment through a rule proposal and issuing a final rule after taking those comments into consideration provides the States with time to withdraw the methods from their programs. In order to provide a comparable timeframe under the expedited process, EPA plans to consult with the States prior to establishing effective dates for withdrawal of methods under the expedited process. It is important that the effective date provide time for the States to implement withdrawal, so that States will not be in a position of allowing methods that were disapproved by EPA. The appendix in the CFR will reflect both the approval and withdrawal dates for any method that is withdrawn using the expedited process. Citing both dates will eliminate any confusion as to when/whether a method approval is in effect. D. Additional Comments The April 10, 2007, Federal Register notice solicited comments on the process used by EPA to announce the approval of alternative methods to the methods listed in regulation. EPA also received comments that are indirectly related to the expedited method approval process. Brief discussions of the major topics are presented below. All of the comments and the Agency's response to comments (USEPA 2008) are available in the docket for this action. 1. EPA evaluation process. The expedited approval process allows EPA to approve methods more quickly and commenters support more timely approval of methods. However, shortening the approval process raised the question about whether EPA is changing the way that it evaluates methods prior to issuing approval decisions. Some commenters asked that EPA maintain its high standards for evaluating methods. Other commenters provided recommendations for changing the review process in order to both streamline and strengthen it. The evaluation process is separate from the expedited approval process. EPA is open to improving our evaluation process and to making the process as transparent as possible. EPA appreciates the suggestions and will consider them with any future evaluation of potential improvements to the ATP program. EPA notes that some of the requested changes are already included in our current evaluation protocol. For example, minor modifications to existing methods generally do not require extensive data submissions in order to demonstrate acceptable method performance. 2. Prioritization of method evaluations. EPA recognizes that the ability to approve methods more quickly may result in an increase in the number of methods that are submitted to EPA for evaluation. It was suggested that EPA prioritize method reviews so that methods that provide the greatest benefit are evaluated first. EPA agrees with this approach and intends to give new methods that provide significant advantages over currently approved methods higher priority in the review process. Improvements may be in areas such as waste minimization, reduced analysis time, cost reduction, increased [[Page 31620]] method flexibility, introduction of an innovative technology, etc. Implementation of this approach means that new methods will not necessarily be reviewed/approved in the order in which they are submitted to the Agency. 3. Public comment as part of the method approval process. EPA understands the desire for the public to have an opportunity to comment on methods approved under the expedited approval process. However, introducing a comment period on these alternative methods is not consistent with the expedited process intended by Congress; as a result, EPA does not generally plan to solicit comment on these alternative method approval decisions. The purpose of this alternative procedure is to identify and allow the use of methods that are equally as effective as methods already approved in prior regulations. As a result, the benchmark for these alternatives has already been provided through notice-and-comment rulemaking on the original method(s). In addition, this expedited approval process simply provides a broader set of compliance opportunities for water systems. Finally, EPA expects to use the expedited process only for those alternative methods that are clearly equally effective relative to methods already approved through regulation and that have performance that has been fully evaluated and well documented, as discussed below. EPA methods undergo peer review prior to publication. The experimental results obtained during method development are usually summarized in a report that is included in the docket when the method is approved. The EPA method development research is often published in a peer reviewed journal. In addition, new chemical and radiochemical methods developed by EPA are evaluated according to Agency guidance adopted by the EPA Forum on Environmental Measurements (FEM). (USEPA 2005, 2006a) The method validation principles are based on current, international approaches and guidelines for intralaboratory (single laboratory) and interlaboratory (multiple laboratory) method validation studies. The Agency is developing similar guidance for validation of microbiological methods and that guidance will be adopted when it becomes available. EPA plans to extend the use of the FEM guidance to methods that are reviewed under the ATP program. EPA encourages method developers to consult with the ATP coordinator during the development of their ATP study plans so that the experimental designs incorporate the appropriate tests. EPA intends to work with method developers during this consultation process to be sure that their ATP study plans address the principles outlined in the validation guidance. In addition, EPA plans to solicit external scientific review for ATP methods that involve new technology. The docket will contain the ATP study summary report and the external scientific review comments in order to document the basis for EPA's approval decision. If the method developer submits confidential business information as part of the ATP review process, the information will not be included in the docket. Generally-accepted validation principles are usually followed for methods that are developed by Voluntary Consensus Standard Bodies (VCSBs), such as Standard Methods and ASTM, International. When a new method is adopted by a VCSB, EPA reviews the data generated during development and validation to verify the method is suitable for analyzing drinking water samples. EPA plans to use the expedited method approval process for methods that perform as well as the regulatory methods. The supporting data that EPA uses to make the approval determination will be placed in the docket so that the information is publically available. In unique cases in which EPA believes public comment is warranted prior to approval, EPA may solicit comment through a notice and then issue its decision on approving the alternative method after taking the comments into consideration. 4. Methods recommended for approval. In the April 10, 2007, Federal Register notice (72 FR 17902) (USEPA 2007a), EPA included two examples of methods that were being considered for approval using the expedited approval process. Commenters supported the approval of these methods (i.e., EPA Method 200.5 and Standard Method 6610-04). They also recommended additional methods for consideration. EPA has enough information to make approval determinations for many of the methods that were listed in the public comments. In those cases, EPA is approving them as part of this action. Additional approval decisions are pending submission of data that will allow EPA to further compare the new methods' performance to that obtained by the regulatory methods. III. Summary of Approvals EPA is approving 99 methods, 85 of which are identical to previously approved methods from earlier publications and 14 of which represent new or modified methods. EPA notes that the approval for all of these methods, including the 85 ``identical'' methods previously required a notice-and-comment rulemaking action. A. Methods From Voluntary Consensus Standard Bodies (VCSB) 1. Standard Methods. EPA approved 73 methods in ``Standard Methods Online'' as part of a ``Methods Update Rule'' issued on March 12, 2007 (72 FR 11200) (USEPA 2007b). Identical versions of these methods are also published in the 21st edition of Standard Methods for the Analysis of Water and Wastewater (Walker and Wendelken 2007). EPA recognizes that some States and laboratories prefer the hardcopy version to the electronic version that was previously approved. Since the 21st edition versions of these methods are equally effective relative to the online versions, EPA is approving the 73 methods from the 21st edition in this action. The 21st edition (APHA 2006) can be purchased from American Public Health Association (APHA), 800 I Street, NW., Washington, DC 20001-3710. Six methods were published in ``Standard Methods Online'' too late to be included in the March 12, 2007, Methods Update Rule. These methods are also included in the 21st edition of Standard Methods for the Analysis of Water and Wastewater (APHA 2006). Four of the methods are unchanged and the other two updated methods reflect minor editorial changes to the versions published in the 20th edition of Standard Methods which are approved at 40 CFR 141.23 and 143.4 (Fair 2008a). EPA is approving the following methods because they are equally effective relative to the currently approved versions: ---------------------------------------------------------------------------------------------------------------- SM (21st ed) (APHA 2006) Standard methods online Contaminant Regulation ---------------------------------------------------------------------------------------------------------------- 4500-P E........................... 4500-P E-99 (APHA 1999).... Orthophosphate........ 40 CFR 141.23(k)(1). 4500-P F........................... 4500-P F-99 (APHA 1999).... Orthophosphate........ 40 CFR 141.23(k)(1). [[Page 31621]] 4500-SO4-\2\ C..................... 4500-SO4-\2\ C-97 (APHA Sulfate............... 40 CFR 143.4(b). 1997a). 4500-SO4-\2\ D..................... 4500-SO4-\2\ D-97 (APHA Sulfate............... 40 CFR 143.4(b). 1997a). 4500-SO4-\2\ E..................... 4500-SO4-\2\ E-97 (APHA Sulfate............... 40 CFR 143.4(b). 1997a). 4500-SO4-\2\ F..................... 4500-SO4-2 F-97 (APHA Sulfate............... 40 CFR 143.4(b). 1997a). ---------------------------------------------------------------------------------------------------------------- The 21st edition can be obtained from APHA, 800 I Street, NW., Washington, DC 20001-3710 and the Online methods can be purchased at http://www.standardmethods.org.The November 8, 2006, Ground Water Rule (GWR) (71 FR 65653) (USEPA 2006b) approved Colilert and Colisure media (Standard Method 9223 B, 20th Edition) for determining the presence of E. coli. Those two E. coli media, along with a third medium, Colilert-18 (all part of SM 9223B), were listed in Table IV-1 of the preamble as being approved in the rule. However, due to a publication oversight, the Colilert-18 methodology was omitted in the table at 40 CFR 141.402(c)(2). EPA is using this expedited approval action to correct the inconsistency between the preamble and rule language and clarify the status of Colilert-18 as an approved methodology. Colilert-18, as described in Standard Method 9223 B and published in the 20th edition of Standard Methods for the Analysis of Water and Wastewater (APHA 1998), is equally as effective as the previously promulgated Colilert and Colisure media in Standard Method 9223 B (page 65593 of the GWR preamble, USEPA 2006c) and is therefore approved in this action. Accordingly, EPA is adding the Colilert-18 methodology to the list of approved methods in Appendix A to Subpart C of Part 141. Identical versions of Standard Method 9223 B are published in the 20th and 21st editions of Standard Methods for the Analysis of Water and Wastewater and in ``Standard Methods Online'' (Fair 2008a). Because the methods from all three sources are equally effective, EPA is approving the 21st edition and the 1997 online version of Method 9223 B for the Colilert, Colisure, and Colilert-18 methodologies. These newer versions are equally effective relative to the methods cited at 40 CFR 141.402(c)(2). The 21st edition of Standard Methods (APHA 2006) can be obtained from APHA, 800 I Street, NW., Washington, DC 20001-3710 and Standard Method 9223 B-97 (APHA 1997b) can be purchased at http://www.standardmethods.org.