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 Environmental Protection Agency 40 CFR Part 136
[EPA-HQ-OW-2024-0328; FRL 11799-01-OW]
RIN 2040-AG37
 AGENCY: Environmental Protection Agency (EPA).
 ACTION: Proposed rule.
 SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing to promulgate new methods and update the tables of approved methods for the Clean Water Act. The Clean Water Act requires the EPA to promulgate test procedures for the analysis of pollutants. Promulgating new methods and updating the tables of approved methods increases the quality and consistency of data collected for the purposes of the Clean Water Act. In this rule, the EPA proposes to add new EPA methods for per- and polyfluoroalkyl substances (PFAS) and polychlorinated biphenyl (PCB) congeners, and add methods previously published by voluntary consensus bodies that industries and municipalities would use for reporting under the EPA's National Pollutant Discharge Elimination System permit program. The EPA also proposes to withdraw the seven Aroclor (PCB mixtures) parameters. In addition, the EPA is proposing to simplify the sampling requirements for two volatile organic compounds, and make a series of minor corrections to existing tables of approved methods. This proposed rule does not mandate when a parameter must be monitored or establish a discharge limit.
 DATES: Comments must be received on or before February 20, 2025.
 ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-OW-2024-0328, by any of the following methods: *Federal eRulemaking Portal:**https://www.regulations.gov/​*
                         (our preferred method). Follow the online instructions for submitting comments.
                    *Mail:*
                         U.S. Environmental Protection Agency, EPA Docket Center, Office of Water Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460.
                    *Hand Delivery or Courier:*
                         EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m., Monday-Friday (except Federal Holidays). *Instructions:*
                         All submissions received must include the Docket ID No. for this rulemaking. Comments received may be posted without change to 
                        *https://www.regulations.gov*
                        /, including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Public Participation” heading of the 
                        **SUPPLEMENTARY INFORMATION**
                         section of this document.
 FOR FURTHER INFORMATION CONTACT: Adrian Hanley, Engineering and Analysis Division, Office of Water (4303T), Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460-0001; telephone number: 202-564-1564; email address: 
                        *hanley.adrian@epa.gov.*


SUPPLEMENTARY INFORMATION: Table of Contents I. Public Participation II. General Information III. Background IV. Corrections or Amendments to the Text and Tables of 40 CFR part 136 V. Incorporation by Reference VI. Statutory and Executive Order Reviews I. Public Participation A. Written Comments Submit your comments, identified by Docket ID No. EPA-HQ-OW-2024-0328, at 
                    *https://www.regulations.gov*
                     (our preferred method), or the other methods identified in the 
                    **ADDRESSES**
                     section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. Do not submit to the EPA's docket at 
                    *https://www.regulations.gov*
                     any information you consider to be Confidential Business Information (CBI), Proprietary Business Information (PBI), or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (
                    *i.e.,*
                     on the web, cloud, or other file sharing system). Please visit 
                    *https://www.epa.gov/​dockets*
                     for additional submission information; the full EPA public comment policy; information about CBI, PBI, or multimedia submissions; and general guidance on making effective comments. Publicly available docket materials are available electronically in 
                    *https://www.regulations.gov*
                     at the Water Docket in EPA Docket Center, EPA/DC, EPA West William J. Clinton Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. Any copyright material can be viewed at the Reading Room, please contact the EPA Docket Center, Public Reading Room. The telephone number for the Public Reading Room is 202-566-1744, and the telephone number for the Water Docket is 202-566-2426. Fax: 202-566-9744. Email: 
                    *docket-customerservice@epa.gov.*( print page 6968) II. General Information A. Does this action apply to me? Entities potentially affected by the requirements of this action include: Category
Examples of potentially affected entitiesState, Territorial, and Indian Tribal Governments
States authorized to administer the National Pollutant Discharge Elimination System permitting program; states, territories, and Tribes providing certification under CWA section 401; state, territorial, and Tribal-owned facilities that must conduct monitoring to comply with NPDES permits.Industry
Facilities that must conduct monitoring to comply with NPDES permits; the environmental monitoring industry.Municipalities
Publicly Owned Treatment Works or other municipality-owned facilities that must conduct monitoring to comply with NPDES permits.
 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 types of entities that the EPA is now aware of that could potentially be affected by this action. Other types of entities not listed in the table could also be affected. To determine whether your facility is affected by this action, you should carefully examine the applicability language at 40 CFR 122.1 (NPDES purpose and scope), 40 CFR 136.1 (NPDES permits and CWA) and 40 CFR 403.1 (pretreatment standards purpose and applicability). If you have questions regarding the applicability of this action to a particular entity, consult the appropriate person listed in the preceding 
                    **FOR FURTHER INFORMATION CONTACT**
                     section. B. What action is the Agency taking? Periodically, the EPA updates the approved methods in 40 CFR part 136. This proposed rulemaking is the 24th update to 40 CFR part 136 since its inception in 1973, 22 Method Update Rules and two Routine Method Update Rules. In general, the changes in this action fall into six categories. The first category is withdrawal of the seven Aroclor parameters and associated methods. The second category is withdrawal of outdated methods that have been supplanted by already approved methods at 40 CFR part 136. The third category is a simplification of the sampling and preservation requirements for two volatile organic compound methods. The fourth category includes minor corrections in the text and tables in 40 CFR part 136. The EPA is proposing these revisions to keep current with technology advances, and to improve data quality and consistency for the regulated community. The fifth category is new EPA methods for new parameters that are being added to 40 CFR part 136. The sixth category is new methods published by a voluntary consensus standard body or vendor for new parameters. The following paragraphs provide details on the revisions. The first four categories are discussed in section IV Corrections or Amendments to the Text and Tables of 40 CFR part 136 of this preamble, the fifth and sixth categories are discussed in section V Incorporation by Reference of this preamble. C. What is the Agency's authority for taking this action? The EPA is proposing this regulation under the authorities of sections 301(a), 304(h), and 501(a) of the CWA; 33 U.S.C. 1251, 1311(a), 1314(h) and 1361(a). Section 301(a) of the CWA prohibits the discharge of any pollutant into navigable waters unless the discharge complies with, among other provisions, a NPDES permit issued under section 402 of the CWA. Section 304(h) of the CWA requires the EPA Administrator to “. . .promulgate guidelines establishing test procedures for the analysis of pollutants that shall include the factors which must be provided in any certification pursuant to [section 401 of the CWA] or permit application pursuant to [section 402 of the CWA].” Section 501(a) of the CWA authorizes the EPA Administrator to “. . . prescribe such regulations as are necessary to carry out this function under [the CWA].” The EPA generally has codified its test procedure regulations (including analysis and sampling requirements) for CWA programs at 40 CFR part 136, though some requirements are codified in other parts (
                    *e.g.,*40 CFR Chapter I, Subchapters N and O). III. Background This preamble describes the abbreviations and acronyms used, the legal authority and reasons for the proposed rule, and a summary of the proposed changes and clarifications, and solicits comment from the public. Abbreviations and Acronyms Used in the Preamble AOF: Adsorbable Organic Fluorine ASTM: ASTM International [1] CFR: Code of Federal Regulations CWA: Clean Water Act EPA: The U.S. Environmental Protection Agency GC/MS: Gas Chromatography/Mass Spectrometry H2
                        O2: Hydrogen Peroxide ICP/AES: Inductively Coupled Plasma-Atomic Emission Spectroscopy LC-MS/MS: Liquid Chromatography-Tandem Mass Spectrometry (also used as LC/MS/MS in some methods) NPDES: National Pollutant Discharge Elimination System NTTAA: National Technology Transfer and Advancement Act PAA: Peracetic Acid PCB: Polychlorinated Biphenyl PFAS: Per- and Polyfluoroalkyl Substances POTW: Publicly Owned Treatment Works QC: Quality Control TNI: The NELAC Institute USGS: United States Geological Survey VCSB: Voluntary Consensus Standards Body NPDES permits must include conditions to ensure compliance with the technology-based and water quality-based requirements of the CWA, including in many cases, restrictions on the quantity of specific pollutants that can be discharged. Permittees must use EPA-approved analytical methods that are sensitive enough to detect and measure pollutants at or below permit limits or water quality criteria (CWA section 402(b)(2)(A)). Permits include measurement and reporting requirements for these specific pollutants; however, permittees often have a choice of which approved test procedure they will use when the EPA has approved more than one method for a specific pollutant. The procedures for the analysis of pollutants required by CWA section 304(h) are a central element of the NPDES permit program. Examples of 
                    ( print page 6969)
                    where these EPA-approved analytical methods must be used include the following: (1) applications for NPDES permits, (2) sampling or other reports required under NPDES permits, (3) other requests for quantitative or qualitative effluent data under the NPDES regulations, (4) State CWA 401 certifications, and (5) sampling and analysis required under EPA's General Pretreatment Regulations for Existing and New Sources of Pollution, 40 CFR 136.1, 40 CFR 403.12(b)(5)(v), and 40 CFR 403.12(g)(3). Periodically, the EPA promulgates updates to the approved methods in 40 CFR part 136 to improve data quality and consistency. The changes proposed in this action fall into the following categories. The first category is withdrawal of seven Aroclor mixtures and the associated approved methods for Aroclors from the list of parameters at Table Ic that have been replaced with a method for the PCB congeners and total PCBs at Table Ii that provides a more accurate and complete characterization of the PCB content of samples than Aroclor analyses (see section V.A of this preamble). The second category is withdrawal of outdated methods that includes single-analyte total metal colorimetric methods for twelve metal parameters, a WatersTM
                     anion method, and EPA Method 1664A for the parameter “oil and grease” (see section IV.B of this preamble). The third category is simplifying sampling requirements for purgeable compounds by making the preservation requirement for acrolein and acrylonitrile consistent with the other pollutants analyzed by volatile organic compound methods (see section IV.C of this preamble). The fourth category is minor corrections to the text and tables at 40 CFR part 136 (see section IV.D of this preamble). The fifth category is new EPA methods for new parameters not previously listed at 40 CFR part 136 that will be added by incorporation by reference: per- and polyfluoroalkyl substances (PFAS) by EPA Method 1633A to a new Table Ij, adsorbable organic fluorine (AOF) by EPA Method 1621 to Table Ic, and polychlorinated biphenyl (PCB) congeners by EPA Method 1628 to a new Table Ii (see section V.A of this preamble). The EPA has finalized these three EPA methods and has posted these methods, along with their validation study reports, on EPA's CWA Methods website (
                    *https://www.epa.gov/​cwa-methods*). The sixth category is new methods published by the voluntary consensus standard bodies (VCSBs) or vendors for new parameters not previously listed at 40 CFR part 136 that will be added by incorporation by reference: PFAS analytes by ASTM D8421-24 to Table Ij; peracetic acid (PAA) by Standard Method “4500-PAA Peracetic Acid (Residual),” and hydrogen peroxide (H2
                    O2) by Standard Method “4500-H2
                    O2
                     Hydrogen Peroxide (Residual)” to Table Ib (see section V.B of this preamble). Finally, as a consequence of adding the two new tables for the PCB congeners and PFAS, the format of the numbers for the existing Tables IA through IH are being revised to be called out as Tables Ia through Ih. The use of a lowercase letter in the table identifier is necessary to avoid confusion between the new Table Ii of PCB congeners and the existing Table II with the required containers, preservation techniques, and holding times (see section V.A of this preamble). IV. Corrections or Amendments to the Text and Tables of 40 CFR Part 136 A. Withdrawal of the Aroclor Parameters and the Associated Methods The EPA proposes to withdraw the seven Aroclor parameters listed as PCB-1016, PCB-1221, PCB-1232, PCB-1242, PCB-1248, PCB-1254, and PCB-1260 and their associated methods from Table Ic, Parameters 88-94. Removing these parameters will result in the renumbering of all of the subsequent parameters in that table. This will also result in deletion of footnote 8, and the renumbering of footnotes 9 through 16. All of the methods listed for these parameters are listed elsewhere for other parameters, so none of them will be completely removed from 40 CFR part 136.3. The “PCBs” class of compounds is made up of 209 structurally related but distinct chemicals often called “congeners.” The seven Aroclor parameters are commercial PCB mixtures and were first included in the EPA's 1976 Priority Pollutant List (Appendix A to Part 423, Title 40). These seven PCB mixtures were the only ones for which the EPA had valid methods at that time. However, none of these Aroclor mixtures include all the PCB congeners that may be present in an environmental sample. The EPA developed the original Aroclor methods in the 1970s, when analysis of individual PCB congeners was impractical with the existing affordable analytical technology and in the absence of automated laboratory information management systems. During the multi-laboratory study of Method 608 in the late 1970s, roughly 20% of the Aroclor data were rejected due to poor accuracy, and false negatives (non-detects) were an issue even with samples that were spiked with fresh standards.[2] When used as a surrogate for PCBs, the results from the approved Aroclor methods can create false confidence that PCBs are not present. Given that the manufacturing and use of PCBs have been banned in the U.S. since 1979, most PCBs in the environment have been subjected to extensive changes in composition and concentration through processes that are collectively referred to as “weathering.” Moreover, there are other relevant sources of PCBs to the environment beyond the seven Aroclor parameters that are not accounted for through Aroclor analyses. Aroclor methods were the best available technology when they were validated in 1978, but now there are much more accurate methods. Thus, the EPA is proposing to replace the Aroclor analysis with EPA Method 1628, which detects the 209 PCB congeners directly, either as individual congeners or groups of co-eluting congeners. As demonstrated by the EPA's multi-laboratory study,[3]
                    
                     EPA Method 1628 can be widely implemented because it uses laboratory equipment that is readily available and is already employed by many full-service laboratories. Withdrawal of the Aroclor parameters and associated methods will not have any immediate impact on current NPDES permits because permits that have been issued by the permitting authority can continue until they expire. 40 CFR 122.21(e)(3)(ii) states: “(ii) When there is no analytical method that has been approved under 40 CFR part 136, required under 40 CFR chapter I, subchapter N or O, and is not otherwise required by the Director, the applicant may use any suitable method but shall provide a description of the method. When selecting a suitable method, other factors such as a method's precision, accuracy, or resolution, may be considered when assessing the performance of the method.” EPA anticipates renewed permits will switch to the approved PCB congener method. Given that most permits are renewed every 5 years or less, promulgation of this part of this proposed rule would result in a multi-year phase out of Aroclor analysis. B. Withdrawal of Outdated Methods The EPA proposes to withdraw approval of outdated colorimetric 
                    ( print page 6970)
                    methods for 12 individual metals and one inorganic anions alternate test procedure that the sponsoring organization no longer supports or makes available to the public. The removal of these methods and their associated footnotes will result in renumbering of the following footnotes at the end of Table Ib. 1. The EPA proposes to withdraw 12 single-metal colorimetric methodology types that measure a total metal concentration (
                    *e.g.,*
                     “Aluminum—Total”) from 40 CFR 136.3, Table Ib. There are multiple inductively coupled plasma (ICP) and graphite furnace methods that are more sensitive and provide more accurate results in challenging matrices that are already listed in Table Ib. These ICP and graphite furnace methods are also relatively inexpensive and easily automated, particularly when analyzing for one parameter (as is done for the colorimetric methods that the EPA is proposing to withdraw). The suggestion to withdraw these methods initially came from The NELAC Institute (TNI), which accredits a large portion of the environmental laboratories in the U.S. TNI is unaware of any laboratory that is currently accredited for these outdated colorimetric methods. If the EPA receives compelling reason to not withdraw any of these methods, the EPA will consider keeping some or all of these methods in 40 CFR part 136. Otherwise, the EPA proposes to withdraw the methods in the rows where “Colorimetric” is the listed methodology for the following total metals, listed in order of the parameter number in Table Ib: 3. Aluminum—Total, 6. Arsenic—Total, 8. Beryllium—Total, 10. Boron—Total, 12. Cadmium—Total, 19. Chromium—Total, 22. Copper—Total, 30. Iron—Total, 32. Lead—Total, 34. Manganese—Total, 74. Vanadium—Total, and 75. Zinc—Total. In addition, footnotes pertaining to only these withdrawals will be removed and the remaining footnotes renumbered sequentially. The relevant methods that will be withdrawn are listed here by organization. Standard Methods: 3500-Al B-2020, 3500-As B-2020, 4500-B B-2011, 3500-Cd D-1990, 3500-Cr B-2020, 3500-Cu B and C-2020, 3500 Fe B-2011, 3500-Pb B-2020, 3500-Mn B-2020, 3500-V B-2011, 3500-Zn B-2020, and Footnote 61 that references an aluminon colorimetric method in Standard Methods 19th Edition. ASTM: D2972-15 (A), D1068-15 (C). USGS: Methods I-3060-85 and I-3112-85. Hach: Footnote 19 that references Method 8506, Bicinchoninate Method for Copper, Hach Handbook of Water Analysis, 1979; Footnote 22 that references Method 8008, 1,10-Phenanthroline Method using FerroVer Iron Reagent for Water, 1980; Footnote 23 that references Method 8034, Periodate Oxidation Method for Manganese, Hach Handbook of Wastewater Analysis, 1979; and Footnote 33 that references Method 8009, Zincon Method for Zinc, Hach Handbook of Water Analysis, 1979. AOAC International: Footnote 3 that references Method 920.203, the persulfate oxidation procedure from the Official Methods of Analysis of the Association of Official Analytical Chemists, Methods Manual, Sixteenth Edition, 4th Revision, 1998. 2. The EPA also proposes to withdraw from Table Ib the WatersTM
                     Corporation alternate test procedure: “Method D6508 Rev.2, Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte.” The WatersTM
                     Corporation no longer supports this method and no longer provides copies of this method to the public. WatersTM
                     developed their alternative test procedure to incorporate additional analysis techniques into an older ASTM standard. The method modifications developed by WatersTM
                     were incorporated into later versions of the ASTM standard, including D6508-15, which is the currently approved method for the same anions: bromide, chloride, fluoride, nitrate, nitrate-nitrite, nitrite, orthophosphate, and sulfate (86 FR 27226, May 19, 2021). Both the WatersTM
                     and ASTM methods are capillary ion electrophoresis methods that provide a simultaneous separation and determination of several inorganic anions and identifies all anions present in the sample by indirect UV detection. The EPA proposes to remove the eight occurrences of Method D6508 Rev. 2 from Table Ib. They are found in parameters: 11. Bromide, 16. Chloride, 25. Fluoride-Total, 38 Nitrate (as N), 39. Nitrate-nitrite (as N), 40. Nitrite (as N), 44. Ortho-phosphate (as P), and 65. Sulfate (as SO4). 3. The EPA proposes to withdraw EPA Method 1664, Revision A: N-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated N-Hexane Extractable Material (SGTHEM; Non-polar Material) by Extraction and Gravimetry, approved at 64 FR 26315, May 14, 1999, from Table Ib, parameter 41. A later revision of Method 1664, (1664 Rev. B), was approved by the EPA in a 2012 rulemaking, 77 FR 29758, May 18, 2012. That 2012 rule strongly recommended laboratories and permitting authorities replace Method 1664, Rev. A with Method 1664, Rev. B. The 2012 rule also said that the EPA would revisit withdrawing Method 1664, Rev. A in a future rulemaking (77 FR 29758, May 18, 2012). Laboratories and regulatory entities have had more than 12 years to make this adjustment, so the EPA is proposing to withdraw Method, 1664, Rev. A from Table Ib, for parameter 41. Oil and Grease—Total recoverable. C. Simplify the Sampling and Preservation Requirements for Two Purgeable Organic Compounds (Often Referred to as Volatile Organic Compounds) The EPA proposes to change the sampling and preservation requirements for acrolein and acrylonitrile to match those of the other purgeable halocarbons and purgeable aromatic hydrocarbons in Table II under the section for parameters in Table Ic. The EPA proposes to change the preservation pH requirement from pH 4-5 to a pH of 2, and to use hydrochloric acid to adjust the sample pH, to align with the approved practice for other purgeable organic compounds. The Environmental Monitoring Coalition provided the EPA with the results from a study using multiple wastewater types that demonstrated that the analysis of acrolein and acrylonitrile is not adversely affected by the lower pH preservation. That Environmental Monitoring Coalition study report: “Evaluating Preservation Requirements for Acrolein and Acrylonitrile in Aqueous Matrices,” is provided in the docket. Thus, the EPA is proposing these changes to make the sampling, analysis, and data reporting more efficient for purgeable organic compound methods. D. Minor Corrections and Amendments to the Texts and Tables of 40 CFR Part 136 Stakeholders have identified several minor errors in Tables Ib, Id, and II. The EPA proposes to correct the following entries in those tables. 1. The EPA proposes to remove the row for the methodology “Amperometric direct (low level)” in Table Ib, parameter 17A, Chlorine-Free Available, because the only method listed in that row, Standard Method 4500 Cl E, measures Total Residual Chlorine (
                    *e.g.,*
                     parameter 17), not free chlorine. The method will remain in the corresponding row for Residual Chlorine parameter 17, where the parameter matches the method. 2. The EPA proposes to amend Table Ib parameter 24 by adding 4500-CN P-2021 and D7511(17) to allow use of any method approved for measurement of Total Cyanide in both the untreated and 
                    ( print page 6971)
                    treated fractions of a sample for determination of available cyanide by cyanide amenable to chlorination (CATC), provided the treatment steps in the two currently approved amenable cyanide methods, 4500-CN G-2016 and ASTM D2036-09(15)(B), are followed. 3. The EPA proposes to add EPA Method 625.1 as an approved method for the parameter Parathion ethyl, parameter 53 in Table Id. The use of EPA Method 625.1 was incorrectly omitted from Table Id for this parameter the last time that Table Id was updated (82 FR 40836, August 28, 2017) because the method lists this analyte as “Parathion,” rather than Parathion ethyl. EPA Method 625.1 measures aqueous samples by extracting them with methylene chloride at pH 11—13 and again at a pH less than 2 using a separatory funnel or continuous liquid/liquid extractor. Then the extract is concentrated and analyzed by GC/MS. 4. The EPA proposes to apply footnote 9 to the entry for EPA Method 1613B in Table Ic for parameter 96, 2,3,7,8-Tetrachloro-dibenzo-
                    *p*
                    -dioxin (formerly listed a parameter 103). This footnote (formerly listed as footnote 10) was to be added to all 17 dioxin and furan congeners in a previous rule (88 FR 10739, February 21, 2023) but was inadvertently missed for this parameter. 5. The EPA proposes to add sodium thiosulfate, Na2
                    S2
                    O3, to the preservation column for parameter 4, Ammonia, under Table Ib in Table II, and apply Footnote 5 to that entry to address the fact that residual chlorine in samples will react with ammonia to form chloramines, which are an interference with ammonia analyses. The EPA also is adding the following text to the end of Footnote 5, “Section A.2 of Standard Method 4500-NH3 discusses the need for dechlorination of samples for ammonia analysis.” 6. The EPA proposes to edit Footnote 17 to Table II under the section for parameters in Table Ib, as applied to parameter 35 for “Mercury (CVAFS)” to include mention of EPA Method 245.7 along with EPA Method 1631 in the footnote. Both methods employ the same cold vapor atomic fluorescence spectroscopy (CVAFS) determinative technique and including EPA Method 245.7 in the footnote will help clarify that the 90-day holding time applies to EPA Method 245.7 as well as EPA Method 1631. Currently, Method 245.7 is not specifically mentioned in Table II, which was an oversight. 7. The EPA proposes to specify in Table II that sodium thiosulfate is to be added to samples to remove oxidants (
                    *e.g.,*
                     chlorine) for the Table 1B parameter 48 (Phenols) and the Table 1C parameters 107 to 111 (Alkylated phenols). The EPA also proposes to restore footnote 5 in Table II for Table 1C parameters 23, 30, 44, 49, 53, 77, 80, 81, 91, 93, and 105 (Phenols), and to add Footnote 5 for Table 1C parameters 112 (Adsorbable Organic Halides) and 113 (Chlorinated Phenolics), and to clarify that the addition of sodium thiosulfate is only necessary when oxidants are present (
                    *e.g.,*
                     chlorine). 8. The EPA proposes to add a new footnote to Table II under Table Ib and apply it to the entry for parameter 50, Phosphorus—Total. The new Footnote 25 addresses the fact that many laboratories determine total phosphorus using EPA Method 200.7, an ICP/AES procedure for metals that is also approved for phosphorus. However, as laboratories often note, the acid specified in Table II to preserve metals samples is nitric acid, where Table II calls out sulfuric acid for phosphorous. In both cases the specified pH is a value less than or equal to 2. In addition, while Table II allows acidified samples to held for 6 months, it only allows phosphorus samples to be held for 28 days. The new Footnote 25 reads: “When EPA Method 200.7 or another approved ICP/AES method is used to determine total phosphorus, sulfuric acid may be used to preserve the sample to pH ≤ 2, or the acid-preserved sample for metals may be used for analysis, and the holding time for total phosphorus may be extended to 6 months.” V. Incorporation by Reference Currently, hundreds of methods and alternate test procedures are incorporated by reference within 40 CFR part 136. In most cases, 40 CFR part 136 contains multiple approved methods for a single parameter (or pollutant) and regulated entities often have a choice in selecting a method. The proposed rule contains VCSB methods that are incorporated by reference (see section V.B of this preamble). The proposed VCSB methods are consistent with the requirements of the National Technology Transfer and Advancement Act (NTTAA), under which Federal agencies should use technical standards developed or adopted by the VCSBs if compliance would not be inconsistent with applicable law or otherwise impracticable (see section VI of this preamble). The proposed copyrighted VCSB methods are available on their respective websites (standardmethods.org and astm.org) to everyone at a cost determined by the VCSB, generally from $60 to $80. Both organizations also offer memberships or subscriptions that allow unlimited access to their methods. The cost of obtaining these methods is not a significant financial burden for a discharger or environmental laboratory, making the methods reasonably available. This proposal includes EPA Method 1621, EPA Method 1628, and EPA Method 1633A (see section V.A of this preamble) and ASTM D8421-24, Standard Method “4500-PAA Peracetic Acid (Residual)”, and Standard Method “4500-H2O2 Hydrogen Peroxide (Residual)” for four parameter types (see section V.B of this preamble) which the EPA proposes to incorporate by reference. The EPA methods and the vendor methods are available free of charge on their respective websites, therefore the EPA methods and vendor methods incorporated by reference are reasonably available. Other standards appear in the amendatory text of this document and have already been approved for the locations in which they appear. A. Changes to 40 CFR 136.3 To Include Three New EPA Methods and Their Associated Parameters The EPA proposes to add three new EPA methods and their associated parameters to 40 CFR 136.3: EPA Method 1621: Determination of Adsorbable Organic Fluorine (AOF) in Aqueous Matrices by Combustion Ion Chromatography (CIC), EPA Method 1628: Polychlorinated Biphenyl (PCB) Congeners in Water, Soil, Sediment, Biosolids, and Tissue by Low-resolution GC/MS using Selected Ion Monitoring, and EPA Method 1633A: Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS. All three of these methods have multi-laboratory validation studies that demonstrate they perform well in a wide variety of wastewater types at multiple laboratories. These methods include performance (or quality control) criteria that the EPA generated by statistically analyzing the data from the multi-laboratory validation studies. The multi-laboratory validation study reports and methods are available to the public on the EPA's Clean Water Act Analytical Methods website at 
                    *https://www.epa.gov/​cwa-methods,*
                     and in the docket to this proposed rulemaking. Adding these methods and parameters to 40 CFR part 136 does not require the permitting authority to require monitoring for those parameters, but it informs the permitting authority and discharger that there is an available method that has been validated and tested. Once these methods are finalized in 40 CFR part 136, then use of the approved test procedure is required if 
                    ( print page 6972)
                    any of these parameters are added to a NPDES permit. The EPA proposes to add the parameter “Adsorbable Organic Fluorine,” (AOF) to Table Ic with the approved test procedure EPA Method 1621. EPA Method 1621 determines adsorbable organic fluorine by passing an aqueous sample through two granular activated carbon columns. The columns are rinsed with sodium nitrate to remove inorganic fluoride, combusted at ≥1000 °C in an oxygen or oxygen/argon stream, and the gaseous hydrogen fluoride is absorbed into reagent water. The fluoride is separated by ion chromatography (IC), identified by comparing sample fluoride retention time to retention times for calibration standards acquired under identical Ic conditions, and then quantified using the external standard technique. The EPA proposes to redesignate all tables in 136.3 with a lower case letter, for example Table IA would be “Table Ia—List of Approved Biological Methods for Wastewater and Sewage Sludge.” This redesignation of the table titles is needed to avoid confusion with the currently existing Table II (Roman numeral two) and the new table for PCBs in order to distinguish between Roman numeral one followed by the letter “I” and Roman numeral two. Then Tables Ii and Ij will be added, as discussed below. The number format for Table II—Required Containers, Preservation Techniques, and Holding Times will remain unchanged. The EPA proposes to add the 209 Polychlorinated Biphenyl (PCB) Congeners and Total PCBs as new parameters in a new Table Ii with the approved test procedure EPA Method 1628. Method 1628 detects all PCB 209 congeners, which are all the compounds that make up the class of chemicals called “PCBs.” The new parameter called “Total PCBs” will be the summation of all the detected PCB congeners in the sample as determined by Method 1628. The summation will use zero (0) for the contribution of the congeners that are not detected. Otherwise, every method blank would have a non-zero result, even when no congeners are detected, affecting assessments of the sample results relative to the method blank. There is no method detection limit (MDL) for Total PCBs because it is the sum of the results for many individual parameters. Method blanks and samples with no detects are reported as “ND” for non-detect, or a similarly appropriate non-numeric value. Method 1628 analyzes samples by spiking them with isotope dilution standards, extracting the PCBs using separatory funnel extraction or solid-phase extraction, cleaning the extracts with a Florisil® column, and analyzing the sample extracts using GC/MS with selected ion monitoring. Because the full names of the PCB congeners are long and contain many numbers indicating the positions of the chlorine substituents (
                    *e.g.,*
                     2,3,3′,4,4′,5-Hexachlorobiphenyl), they are often expressed as a “congener number” in the format “PCB-XYZ,” where “XYZ is a number between 1 and 209. The EPA has included the congener numbers in Table Ii to facilitate consistency in reporting of the results for these new parameters. The EPA proposes to add the 40 target PFAS analytes in Method 1633A as new parameters in a new Table Ij, with the approved test procedure EPA Method 1633A. Method 1633A analyzes samples by spiking them with isotope dilution standards, subjecting them to solid-phase extraction and activated carbon cleanup, and analyzing the sample extracts using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The EPA proposes to add these new parameters to the relevant section of Table II—Required Containers, Preservation Techniques, and Holding Times. The specifications for the containers, preservation techniques, and holding times for these parameters are the same as the specifications provided in the method. B. Changes to 40 CFR 136.3 To Include New Parameters and Methods Published by VCSBs and Vendors The EPA solicited VCSBs and relevant vendors to submit methods, along with study reports and validation data, for the following parameters: the PFAS parameters listed in Method 1633A, peracetic acid, and hydrogen peroxide. The VCSBs or vendors submitted data that demonstrate that their methods can be used at multiple laboratories and can reliably detect and quantify the parameter in a wide variety of wastewater types (as the EPA does with its own CWA methods). The methods and multi-laboratory study reports for each of the following methods are in the docket for this rulemaking. The EPA proposes to add the following parameters and methods to 40 CFR part 136. The EPA also proposes to add these new parameters to the relevant section of Table II—Required Containers, Preservation Techniques, and Holding Times. The specifications for the containers, preservation techniques, and holding times for peracetic acid, and hydrogen peroxide are the same as the specifications provided in the methods. The preservation and holding time specifications for the PFAS parameters parallel those from EPA Method 1633A. 1. “ASTM D8421-24 Standard Test Method for Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Matrices by Co-solvation followed by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS),” as an approved test procedure for the 40 PFAS analytes being added as new parameters in Table Ij. ASTM D8421-24 analyzes aqueous samples by adding labeled surrogates to a 5-mL sample in the original container, adding 5 mL of methanol, filtering the sample, adjusting the pH and injecting a small aliquot of the extract into an LC-MS/MS instrument. 2. The EPA proposes to add the parameter “Peracetic acid (PAA)” to Table Ib and approve Standard Method “4500-PAA Peracetic Acid (Residual).” This method uses a simple handheld instrument that uses N,N-diethyl-p-phenylenediamine (DPD) chemical indicator (for PAA) followed by colorimetric detection. It is similar to the colorimetric methods used for residual chlorine. This new parameter will provide POTWs and other wastewater treatment permittees that utilize peracetic acid as an alternative to chlorine-based disinfectants with an approved method to monitor their discharges. 3. The EPA also proposes to add the parameter “Hydrogen Peroxide (H2
                    O2),” to Table Ib and approve Standard Method “4500-H2
                    O2
                     Hydrogen Peroxide (Residual).” This method uses a simple handheld instrument that uses ferric thiocyanate chemical indicator (for H2
                    O2) followed by colorimetric detection. It is similar to the colorimetric methods used for residual chlorine. Hydrogen peroxide is a by-product of the use of Peracetic acid as an alternative to chlorine-based disinfectants and in conjunction with the addition of the new parameter “Peracetic acid (PAA),” Standard Method “4500-H2
                    O2
                     Hydrogen Peroxide (Residual) will provide POTWs and other wastewater treatment permittees that utilize peracetic acid with approved methods to monitor their discharges. VI. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review Executive Order 14094: Modernizing Regulatory Review This action is not a significant regulatory action as defined in Executive Order 12866, as amended by Executive Order 14094, and was therefore not subject to a requirement for Executive Order 12866 review.
                    ( print page 6973) B. Paperwork Reduction Act This action does not impose an information collection burden under the Paperwork Reduction Act. This rule does not impose any information collection, reporting, or recordkeeping requirements. This proposal would merely add or revise CWA test procedures. C. Regulatory Flexibility Act I certify that this action would not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act. This action would not impose any requirements on small entities. This action would approve new and revised versions of CWA testing procedures. Generally, these changes improve data quality. In general, the EPA expects the proposed revisions would lead to few direct costs. Adding these parameters and methods to 40 CFR part 136 does not require the permitting authority to require monitoring that parameter, but it informs the permitting authority and discharger that there is an available method that has been validated and tested in a wide variety of wastewater types. If a permittee is already monitoring for one of more of the parameters, then the permittee may need to change methods. This would not be a significant change in cost, given that the permittee is already paying a laboratory to analyze for the parameter(s). The EPA proposes methods that would be incorporated by reference. If a permittee elected to use these methods, they could incur a small cost associated with obtaining these methods from the listed sources. See section IV of this preamble. D. Unfunded Mandates Reform Act This action does not contain an unfunded mandate as described in the Unfunded Mandates Reform Act, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. The action imposes no enforceable duty on any state, local or tribal governments or the private sector. E. Executive Order 13132: Federalism This proposed rule does not have federalism implications. It would not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government. F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments This proposed rule does not have tribal implications as specified in Executive Order 13175. This rule would merely approve new and revised versions of test procedures. The EPA does not expect the proposal would lead to any costs to any tribal governments, and if incurred, the EPA projects they would be minimal. Thus, Executive Order 13175 does not apply to this action. G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks EPA interprets Executive Order 13045 as applying only to those regulatory actions that concern environmental health or safety risks that the EPA has reason to believe may disproportionately affect children, per the definition of “covered regulatory action” in section 2-202 of the Executive Order. Therefore, this action is not subject to Executive Order 13045 because it does not concern an environmental health risk or safety risk. Since this action does not concern human health, the EPA's policy on Children's Health also does not apply. H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use This action is not subject to Executive Order 13211 because it is not a significant regulatory action under Executive Order 12866. I. National Technology Transfer and Advancement Act of 1995 This action involves technical standards. The EPA proposes to approve the use of technical standards developed and recommended by the Standard Methods Committee and ASTM International for use in compliance monitoring where the EPA determined that those standards meet the needs of CWA programs. As described above, this proposal is consistent with the NTTAA. J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations and Executive Order 14096: Revitalizing Our Nation's Commitment to Environmental Justice for All The EPA believes that this type of action does not concern human health or environmental conditions and therefore cannot be evaluated with respect to potentially disproportionate and adverse effects on communities with environmental justice concerns. This action has no effect on communities because this action will approve new CWA testing procedures. These changes would provide increased flexibility for the regulated community in meeting monitoring requirements while improving data quality. Adding new parameters to 40 CFR part 136 does not require the parameters to be monitored. In addition, this update to the CWA methods will incorporate technological advances in analytical technology. Although this action does not concern human health or environmental conditions, the EPA identifies and addresses environmental justice concerns by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on minority populations (people of color) and low-income populations. List of Subjects in 40 CFR Part 136 Environmental protection
Incorporation by reference
Reporting and recordkeeping requirements
Test procedures
Water pollution control
 Michael S. Regan, Administrator.
 For the reasons set forth in the preamble, the EPA proposes to amend 40 CFR part 136 as follows: PART 136—GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS
 1.The authority citation for part 136 continues to read as follows: Authority:
                    Secs. 301, 304(h), 307 and 501(a), Pub. L. 95-217, 91 Stat. 1566, 
                        *et seq.*
                         (33 U.S.C. 1251, 
                        *et seq.*) (the Federal Water Pollution Control Act Amendments of 1972 as amended by the Clean Water Act of 1977). 2.Amend § 136.3 by: a.Redesignating tables IA through IH as tables Ia through Ih, respectively; b.In paragraph (a): i.Revising the introductory text; ii. Revising newly redesignated tables Ib and Ic; iii. In newly redesignated table Id, revising the third column heading and the entry for “53. Parathion ethyl”; iv. Adding in alphabetical order tables Ii and Ij; and c.In paragraph (b): i.Revising the introductory text; ii. Redesignating paragraphs (b)(8)(xi) through (xvi) as paragraphs (b)(8)(xiv) through (xix) and adding new paragraphs (b)(8)(xi) through (xiii); iii. Revising and republishing paragraph (b)(10);
                    ( print page 6974) iv. Removing paragraph (b)(13)(i)(A), and redesignating paragraphs (b)(13)(i)(B) through (X) as paragraphs (b)(13)(i)(A) through (W); v.Adding paragraph (b)(15)(lxxi); vi. Removing paragraphs (b)(20)(ii) through (v), and redesignating paragraphs (b)(20)(vi) through (x) as paragraphs (b)(ii) through (vi); vii. Revising paragraph (b)(38)(i); and viii. Removing paragraph (b)(41). d.In paragraph (e), table II: i.Redesignating entries “Table IA” through “Table IH” as “Table Ia” “through Table Ih”, respectively; ii. Revising the entry for “4. Ammonia” under Table Ib-Inorganic Tests; iii. Revising entries for “48. Phenols” and “50. Phosphorus, total”, and adding entries for “77. Hydrogen Peroxide” and “78. Peracetic Acid” under Table Ib—Metals; iv. Revising the table entitled “Table Ic-Organic Tests”; v.Adding in alphabetical order entries for “Table Ii—Polychlorinated Biphenyl Congener Tests” and “Table Ij—Per- and Polyfluorinated Alkyl Substances Tests”; vi. Revising footnotes 5 and 17 and vii. Adding footnotes 25 through 29. The revisions and additions read as follows: § 136.3
  (a) Parameters or pollutants, for which methods are approved, are listed together with test procedure descriptions and references in Tables Ia, Ib, Ic, Id, Ie, If, Ig, Ih, Ii, and Ij of this section. The methods listed in Tables Ia, Ib, Ic, Id, Ie, If, Ig, Ih, Ii, and Ij are incorporated by reference, see paragraph (b) of this section, with the exception of EPA Methods 200.7, 601-613, 624.1, 625.1, 1613, 1624, and 1625. The full texts of Methods 601-613, 624.1, 625.1, 1613, 1624, and 1625 are printed in appendix A of this part, and the full text of Method 200.7 is printed in appendix C of this part. The full text for determining the method detection limit when using the test procedures is given in appendix B of this part. In the event of a conflict between the reporting requirements of 40 CFR parts 122 and 125 and any reporting requirements associated with the methods listed in these tables, the provisions of 40 CFR parts 122 and 125 are controlling and will determine a permittee's reporting requirements. The full texts of the referenced test procedures are incorporated by reference into Tables Ia, Ib, Ic, Id, Ie, If, Ig, Ih, Ii, and Ij. The year after the method number indicates the latest editorial change of the method. The discharge parameter values for which reports are required must be determined by one of the standard analytical test procedures incorporated by reference and described in Tables Ia, Ib, Ic, Id, Ie, If, Ig, Ih, Ii, and Ij, or by any alternate test procedure which has been approved by the Administrator under the provisions of paragraph (d) of this section and §§ 136.4 and 136.5. Under certain circumstances (paragraph (c) of this section, in § 136.5(a) through (d) or 40 CFR 401.13) other additional or alternate test procedures may be used. 
 
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  
 
  (b) The material listed in this paragraph (b) is incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved incorporation by reference (IBR) material is available for inspection at the EPA and at the National Archives and Records Administration (NARA). Contact the EPA at: EPA's Water Docket, EPA West, 1301 Constitution Avenue NW, Room 3334, Washington, DC 20004; phone: 202-566-2426; email: docket-
                        *customerservice@epa.gov.*
                         For information on the availability of this material at NARA, visit 
                        *www.archives.gov/​federal-register/​cfr/​ibr-locations*
                         or email 
                        *fr.inspection@nara.gov.*
                         The material may be obtained from the following sources in this paragraph (b). 
 (8) * * * 
 (xi) Method 1621, Determination of Adsorbable Organic Fluorine (AOF) in Aqueous Matrices by Combustion Ion Chromatography (CIC). EPA 821-R-24-002. Table Ic. (xii) Method 1628 Method 1628 Polychlorinated Biphenyl (PCB) Congeners in Water, Soil, Sediment, Biosolids, and Tissue by Low-resolution GC/MS using Selected Ion Monitoring. July 2021. EPA 821-R-21-002. Table Ii. (xiii) Method 1633A Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS. EPA-820-R-24-007. Table Ij. 
 (10) American Public Health Association, 800 I Street, NW, Washington, DC 20001; phone: 202-777-2742; website: 
                        *www.standardmethods.org.* (i) Standard Methods for the Examination of Water and Wastewater. 14th Edition, 1975. Table Ib, Notes 27 and 86. (ii) Standard Methods for the Examination of Water and Wastewater. 15th Edition, 1980, Table Ib, Note 30; Table Id. (iii) Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency, Supplement to the 15th Edition of Standard Methods for the Examination of Water and Wastewater. 1981. Table Ic, Note 6; Table Id, Note 6. (iv) Standard Methods for the Examination of Water and Wastewater. 18th Edition, 1992. Tables Ia, Ib, Ic, Id, Ie, and . (v) Standard Methods for the Examination of Water and Wastewater. 19th Edition, 1995. Tables Ia, Ib, Ic, Id, Ie, and Ih. (vi) Standard Methods for the Examination of Water and Wastewater. 20th Edition, 1998. Tables Ia, Ib, Ic, Id, Ie, and Ih. (vii) Standard Methods for the Examination of Water and Wastewater. 21st Edition, 2005. Table Ib, Notes 17 and 27. (viii) 2120, Color. Revised September 4, 2021. Table Ib. (ix) 2130, Turbidity. Revised 2020. Table Ib. (x) 2310, Acidity. Revised 2020. Table Ib. (xi) 2320, Alkalinity. Revised 2021. Table Ib. (xii) 2340, Hardness. Revised 2021. Table Ib. (xiii) 2510, Conductivity. Revised 2021. Table Ib. (xiv) 2540, Solids. Revised 2020. Table Ib. (xv) 2550, Temperature. 2010. Table Ib. (xvi) 3111, Metals by Flame Atomic Absorption Spectrometry. Revised 2019. Table Ib. (xvii) 3112, Metals by Cold-Vapor Atomic Absorption Spectrometry. Revised 2020. Table Ib. (xviii) 3113, Metals by Electrothermal Atomic Absorption Spectrometry. Revised 2020. Table Ib. (xix) 3114, Arsenic and Selenium by Hydride Generation/Atomic Absorption Spectrometry. Revised 2020, Table Ib. (xx) 3120, Metals by Plasma Emission Spectroscopy. Revised 2020. Table Ib. (xxi) 3125, Metals by Inductively Coupled Plasma-Mass Spectrometry. Revised 2020. Table Ib. (xxii) 3500-Ca, Calcium. Revised 2020. Table Ib. (xxiii) 3500-Cr, Chromium. Revised 2020. Table Ib.
                        ( print page 7030) (xxiv) 3500-K, Potassium. Revised 2020. Table Ib. (xxv) 3500-Na, Sodium. Revised 2020. Table Ib. (xxvi) 4110, Determination of Anions by Ion Chromatography. Revised 2020. Table Ib. (xxvii) 4140, Inorganic Anions by Capillary Ion Electrophoresis. Revised 2020. Table Ib. (xxviii) 4500 Cl−, Chloride. Revised 2021. Table Ib. (xxix) 4500-Cl, Chlorine (Residual). 2011. Table Ib. (xxx) 4500-CN−, Cyanide. Revised 2021. Table Ib. (xxxi) 4500-F−, Fluoride. Revised 2021. Table Ib. (xxxii) 4500-H+
                        , pH. 2021. Table Ib. (xxiii) 4500-H2O2 Hydrogen Peroxide (Residual) 2020. Table Ib. (xxxiv) 4500-NH3, Nitrogen (Ammonia). Revised 2021. Table Ib. (xxxv) 4500-NO2−, Nitrogen (Nitrite). Revised 2021. Table Ib. (xxxvi) 4500-NO3−, Nitrogen (Nitrate). Revised 2019. Table Ib. (xxxvii) 4500-N(org), Nitrogen (Organic). Revised 2021. Table Ib. (xxxviii) 4500-O, Oxygen (Dissolved). Revised 2021. Table Ib. (xxxix) 4500-P, Phosphorus. Revised 2021. Table Ib. (xl) 4500-PAA Peracetic Acid (Residual) 2019. Table Ib. (xli) 4500-SiO2, Silica. Revised 2021. Table Ib. (xlii) 4500-S2−, Sulfide. Revised 2021. Table Ib. (xliii) 4500-SO32−, Sulfite. Revised 2021. Table Ib. (xliv) 4500-SO42−, Sulfate. Revised 2021. Table Ib. (xlv) 5210, Biochemical Oxygen Demand (BOD). Revised 2016. Table Ib. (xlvi) 5220, Chemical Oxygen Demand (COD). 2011. Table Ib. (xlvii) 5310, Total Organic Carbon (TOC). Revised 2014. Table Ib. (xlviii) 5520, Oil and Grease. Revised 2021. Table Ib. (xlix) 5530, Phenols. Revised 2021. Table Ib. (l) 5540, Surfactants. Revised 2021. Table Ib. (li) 6200, Volatile Organic Compounds. Revised 2020. Table Ic. (lii) 6410, Extractable Base/Neutrals and Acids. Revised 2020. Tables Ic and Id. (liii) 6420, Phenols. Revised 2021. Table Ic. (liv) 6440, Polynuclear Aromatic Hydrocarbons. Revised 2021. Table Ic. (lv) 6630, Organochlorine Pesticides. Revised 2021. Table Id. (lvi) 6640, Acidic Herbicide Compounds. Revised 2021. Table Id. (lvii) 7110, Gross Alpha and Gross Beta Radioactivity (Total, Suspended, and Dissolved). 2000. Table Ie. (lviii) 7500, Radium. 2001. Table Ie. (lix) 9213, Recreational Waters. 2007. Table Ih. (lxx) 9221, Multiple-Tube Fermentation Technique for Members of the Coliform Group. Approved 2014. Table Ia, Notes 12, 14; and 33; Table Ih, Notes 10, 12, and 32. (lxi) 9222, Membrane Filter Technique for Members of the Coliform Group. 2015. Table Ia, Note 31; Table Ih, Note 17. (lxii) 9223 Enzyme Substrate Coliform Test. 2016. Table Ia; Table Ih. (lxiii) 9230 Fecal Enterococcus/Streptococcus Groups. 2013. Table Ia, Note 32; Table Ih. 
 (15) * * * 
 (lxxi) ASTM D8421-24, Standard Test Method for Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Matrices by Co-solvation followed by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS). June 2024. Table Ij. 
 (38) * * * (i) Organochlorine Pesticides and PCBs in Wastewater Using EmporeTM Disk Test Method 3M 0222. Revised October 28, 1994. Table Id, Note 8. 
 (e) * * *


# Footnotes

1.
    
                             Formerly known as the American Society for Testing and Materials (ASTM). Back to Citation
 2.
    
                         EPA document EPA-600/4-84-061, “EPA Method Study 18 Method 608—Organochlorine Pesticides and PCBs.” June 1984. Back to Citation
 3.
    
                         EPA document EPA 820-R-21-003, “Report on the Multi-laboratory Validation of Clean Water Act Method 1628 for PCB Congeners.” April 2021. Back to Citation


BILLING CODE 6560-50-C BILLING CODE 6560-50-P [FR Doc. 2024-29239 Filed 1-17-25; 8:45 am]