4658 Federal Register / Vol. 90, No. 10 / Thursday, January 16, 2025 / Rules and Regulations 

State citation Rule title 

State 

effective 

date 

EPA 

final rule 

date 

Final rule citation Comments 

10.110 ................ When Authorized by the Federal Government—Cessation of Oxygenated Fuels 

Program.

1/16/2024 1/16/2025 [insert first page of Federal 

Register citation].

10.111 ................ Contingency Measure ..................................... 1/16/2024 1/16/2025 [insert first page of Federal 

Register citation].

* * * * * * * 

* * * * * 

[FR Doc. 2025–00380 Filed 1–15–25; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 141 

[EPA–HQ–OW–2024–0603; FRL–12499–01– 

OW] 

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 to 

determine compliance with national 

primary drinking water regulations. The 

Safe Drinking Water Act authorizes EPA 

to approve the use of alternative testing 

methods through publication in the 

Federal Register. EPA is using this 

streamlined authority to make two 

additional methods available for 

analyzing drinking water samples. This 

expedited approach provides public 

water systems, laboratories, and 

primacy agencies with more timely 

access to new measurement techniques 

and greater flexibility in the selection of 

analytical methods, thereby reducing 

monitoring costs while maintaining 

public health protection. 

DATES: This action is effective January 

16, 2025. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. EPA–HQ–OW–2024–0603. All 

documents in the docket are listed on 

the https://www.regulations.gov 

website. Although listed in the index, 

some information is not publicly 

available, e.g., confidential business 

information (CBI) or other information 

whose disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, is not placed on 

the internet and will be publicly 

available only in hard copy form. 

Publicly available docket materials are 

available electronically through https:// 

www.regulations.gov. 

FOR FURTHER INFORMATION CONTACT: 

Teresa Wells, Technical Support 

Branch, Standards and Risk 

Management Division, Office of Ground 

Water and Drinking Water (MS 140), 

Environmental Protection Agency, 26 

West Martin Luther King Drive, 

Cincinnati, OH 45268; telephone 

number: (513) 569–7128; email address: 

wells.teresa@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 the Safe Drinking Water 

Act (SDWA) may measure contaminants 

in water samples. When EPA sets a 

monitoring requirement in its national 

primary drinking water regulations for a 

given contaminant, the agency also 

establishes (in the regulations) 

standardized test procedures for 

analysis of the contaminant. This action 

makes alternative testing methods 

available for particular drinking water 

contaminants beyond the testing 

methods currently established in the 

regulations. EPA is providing public 

water systems, required to test water 

samples, with a choice of using either a 

test procedure already established in the 

existing regulations or an alternative 

testing method that has been approved 

in this action or in prior expedited 

approval actions. Categories and entities 

that may ultimately be affected by this 

action include: 

Category Examples of potentially regulated entities NAICS1

State, local, & Tribal governments .............. State, local, and Tribal governments that analyze water samples on behalf of public 

water systems required to conduct such analysis; State, local, and Tribal governments that directly operate community and non-transient non-community water systems required to monitor.

924110 

Industry ........................................................ Private operators of community and non-transient non-community water systems required to monitoras.221310 

Municipalities ............................................... Municipal operators of community and non-transient non-community water systems required to monitor.924110 

1 North American Industry Classification System. 

This table is not intended to be 

exhaustive, but rather provides a guide 

for readers regarding entities likely to be 

interested in this action. Other types of 

entities not listed in the table could also 

have some interest. To determine 

whether your facility is affected by this 

action, you should carefully examine 

the applicability language in the Code of 

Federal Regulations (CFR) at 40 CFR 

141.2 (definition of a 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. 


ddrumheller on DSK120RN23PROD with RULES1
Federal Register / Vol. 90, No. 10 / Thursday, January 16, 2025 / Rules and Regulations 4659 

Abbreviations and Acronyms Used in 

This Action 

AMCD: Automated Micro Chlorine Detection 

CFR: Code of Federal Regulations 

EPA: United States Environmental Protection 

Agency 

FRB: Field Reagent Blank 

LC/MS/MS: Liquid Chromatography/Tandem 

Mass Spectrometry 

NAICS: North American Industry 

Classification System 

PFAS: Per- and Polyfluorinated Alkyl 

Substances 

SDWA: The Safe Drinking Water Act 

II. Background 

A. What is the purpose of this action? 

In this action, EPA is approving two 

analytical methods for determining 

contaminant concentrations in drinking 

water samples collected under SDWA. 

Regulated entities required to sample 

and monitor may use either the testing 

methods already established in existing 

regulations or the alternative testing 

methods being approved in this action 

or in prior expedited approval actions. 

The new methods are listed along with 

other methods similarly approved 

through previous expedited actions in 

40 CFR part 141, appendix A to subpart 

C and on EPA’s drinking water methods 

website at https://www.epa.gov/ 

dwanalyticalmethods. 

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 testing method through 

publication in the Federal Register (see 

section 1401(1) of SDWA). EPA is using 

this streamlined approval authority to 

make two additional methods available 

for determining contaminant 

concentrations in drinking water 

samples collected under SDWA. EPA 

has determined that, for each 

contaminant or group of contaminants 

listed in section III of this preamble, the 

additional testing methods being 

approved in this action are as effective 

as one or more of the testing methods 

already approved in the regulations for 

those contaminants. Section 1401(1) of 

SDWA 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 two analytical methods 

legally available as options for meeting 

EPA’s monitoring requirements. 

This action does not add regulatory 

language, but does, for informational 

purposes, update an appendix to the 

regulations at 40 CFR part 141 that lists 

all methods approved under section 

1401(1) of SDWA. Accordingly, while 

this action is not a rule, it is updating 

CFR text and therefore is being 

published in the ‘‘Final Rules’’ section 

of the Federal Register. 

III. Summary of Approvals 

EPA is approving two methods that 

are equally effective relative to methods 

previously promulgated in the 

regulations. By means of this action, 

these two methods are added to 

appendix A to subpart C of 40 CFR part 

141. 

A. Methods Developed by EPA 

1. EPA Method 537.1, Version 1.0. 

Determination of Selected Per- and 

Polyfluorinated Alkyl Substances 

(PFAS) in Drinking Water by Solid 

Phase Extraction and Liquid 

Chromatography/Tandem Mass 

Spectrometry (LC/MS/MS) (USEPA 

2018). The EPA’s April 26, 2024, 

Federal Register publication for the 

PFAS National Primary Drinking Water 

Regulation (89 FR 32532) describes EPA 

Method 533 (‘‘Determination of PFAS in 

Drinking Water by Isotope Dilution 

Anion Exchange Solid Phase Extraction 

and LC/MS/MS,’’ November 2019, 815– 

B–19–020) (USEPA 2019) and EPA 

Method 537.1, version 2.0 

(‘‘Determination of Selected PFAS in 

Drinking Water by Solid Phase 

Extraction and LC/MS/MS,’’ March 

2020, EPA/600/R–20/006) (USEPA 

2020) as acceptable methods for the 

analyses specified by the National 

Primary Drinking Water Regulation. 

The primary difference between 

Method 537.1, version 1.0 and Method 

537.1, version 2.0 is the field reagent 

blank (FRB) preparation. Version 2.0 

exposes the FRB to the preservative 

(Trizma) at the time of field sample 

collection, whereas version 1.0 

combines the lab reagent water and the 

preservative together in the FRB prior to 

field sampling. Version 2.0 was created 

to more-closely mimic the FRB process 

used in Method 533. Additionally, 

version 2.0 specifies the use of solid 

phase extraction cartridge sorbents 

containing a styrene divinylbenzene 

polymeric sorbent phase that may not be 

modified with monomers other than 

SDVB. The method versions are 

otherwise identical. 

EPA has determined that EPA Method 

537.1, version 1.0 is equally effective 

relative to Method 537.1, version 2.0 for 

the purposes of the analyses specified in 

40 CFR 141.902(b)(1) [Monitoring 

requirements for PFAS—Initial 

monitoring]. The basis for this 

determination is discussed in Adams 

2024a. Therefore, EPA is approving EPA 

Method 537.1, version 1.0 for 

determination of selected PFAS in 

drinking water to support initial 

monitoring required by the PFAS 

National Primary Drinking Water 

Regulation. EPA Method 537.1, version 

1.0 is available at the National Service 

Center for Environmental Publications 

at https://www.epa.gov/nscep. 

B. Methods Developed by Vendors 

1. e-sens AMCD Method—e-sens, Inc. 

Automated Micro Chlorine Detection 

(AMCD) Method for the Determination 

of Residual Free and Total Chlorine in 

Water (e-sens, Inc. 2023a). e-sens AMCD 

Method uses a three-electrode 

electrochemical cell, comprised of a 

reference electrode, a platinum micro 

array working electrode, and a platinum 

counter electrode. The working 

electrode and the counter electrode are 

batch-produced on a silicon substrate, 

and the electrical outputs are processed 

by an onboard potentiostat. For free 

chlorine, after electrode conditioning, 

the embedded microfluidic system adds 

a precise amount of a concentrated 

phosphate buffer to each sample to 

adjust its ionic strength and pH. A 

standard voltammetry procedure is then 

invoked on the buffered sample and the 

faradaic current through the 

electrochemical cell is recorded. The 

current magnitude is proportional to the 

concentration of free chlorine in the 

sample. The recorded current response 

is fit to a calibration curve obtained 

upon manufacture of the sensor and the 

concentration of free chlorine is 

reported. For total chlorine, the free 

chlorine measurement is immediately 

followed by the total chlorine 

measurement. A new aliquot of sample 

is mixed with ammonium chloride, 

which instantly converts various 

chlorine species to monochloramine. A 

concentrated phosphate buffer is then 

added into the sample to 

disproportionate monochloramine to 

form dichloramine, which is readily 

reduced at the surface of the platinum 

working electrode. A standard 

voltammetry procedure is then invoked 

on the buffered sample and the faradaic 

current through the electrochemical cell 

is recorded. The current magnitude is 

proportional to the concentration of 

total chlorine in the sample. The 

recorded current response is fit to a 

calibration curve obtained upon 

manufacture of the sensor and the 

concentration of total chlorine is 

reported. 

Approved methods for free and total 

chlorine are listed at 40 CFR 

141.74(a)(2) and 141.131(c)(1). The 


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4660 Federal Register / Vol. 90, No. 10 / Thursday, January 16, 2025 / Rules and Regulations 

performance characteristics of e-sens 

AMCD Method were compared to the 

performance characteristics of the 

approved Standard Methods 4500-Cl G 

(APHA 2000). The validation study 

report (e-sens, Inc. 2023b) summarizes 

the results obtained from three different 

laboratories using three different ground 

water matrixes, and three different 

surface water matrixes collected from 

six different locations. 

EPA has determined that e-sens 

AMCD Method is equally effective 

relative to Standard Methods 4500-Cl G. 

The basis for this determination is 

discussed in Adams 2024b. Therefore, 

EPA is approving the e-sens AMCD 

Method for determining free and total 

chlorine in drinking water. A copy of 

the method is available from e-sens, 

Inc., 630 Komas Dr., Ste 235, Salt Lake 

City, Utah 84108. 

IV. Statutory and Executive Order 

Reviews 

As noted in section II of this 

preamble, under the terms of SDWA 

section 1401(1), this streamlined 

method approval action is not a rule. 

Accordingly, the Congressional Review 

Act, 5 U.S.C. 801 et seq., as added by 

the Small Business Regulatory 

Enforcement Fairness Act of 1996, does 

not apply because this action is not a 

rule for purposes of 5 U.S.C. 804(3). 

Similarly, this action is not subject to 

the Regulatory Flexibility Act because it 

is not subject to notice and comment 

requirements under the Administrative 

Procedure Act or any other statute. In 

addition, because this approval action is 

not a rule, but simply makes alternative 

testing methods available as options for 

monitoring under SDWA, EPA has 

concluded that other statutes and 

executive orders generally applicable to 

rulemaking do not apply to this 

approval action. 

V. References 

Adams, W. 2024a. Memo to the record 

describing basis for expedited approval 

of EPA Method 537.1, Version 1.0. 

December 5, 2024. (Available at https:// 

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

Adams, W. 2024b. Memo to the record 

describing basis for expedited approval 

of e-sens Automated Micro Chlorine 

Detection Method November 26, 2024. 

(Available at https://

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

American Public Health Association (APHA). 

2000. Standard Methods 4500-Cl D, E, F, 

G, H, I–00. Chlorine (Residual). D. 

Amperometric Titration Method. E. LowLevel Amperometric Titration Method. 

F. DPD Ferrous Titrimetric Method. G. 

DPD Colorimetric Method. H. 

Syringaldehyde (FACTS) Method. I. 

Iodometric Electrode Technique. 

Approved by Standard Methods 

Committee 2000. Standard Methods 

Online (Available at https://

www.standardmethods.org.) 

USEPA. 2018. EPA Method 537.1, Version 

1.0. Determination of Selected Per- and 

Polyfluorinated Alkyl Substances (PFAS) 

in Drinking Water by Solid Phase 

Extraction and Liquid Chromatography/ 

Tandem Mass Spectrometry (LC/MS/ 

MS). EPA/600/R–18/352. November 

2018. (Available at https://

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

USEPA. 2019. EPA Method 533. 

Determination of PFAS in Drinking 

Water by Isotope Dilution Anion 

Exchange Solid Phase Extraction and LC/ 

MS/MS. EPA 815–B–19–020. November 

2019. (Available at https://

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

USEPA. 2020. EPA Method 537.1, Version 

2.0. Determination of Selected Per- and 

Polyfluorinated Alkyl Substances (PFAS) 

in Drinking Water by Solid Phase 

Extraction and Liquid Chromatography/ 

Tandem Mass Spectrometry (LC/MS/ 

MS). EPA/600/R–20/006. March 2020. 

(Available at https://

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

e-sens, Inc. 2023a. e-sens AMCD Method. esens, Inc. Automated Micro Chlorine 

Detection (AMCD) Method for the 

Determination of Residual Free and Total 

Chlorine in Water. December 2023. 

(Available at https://

www.regulations.gov; docket ID No. 

EPA–HQ–OW–2024–0603.) 

e-sens, Inc. 2023b. Alternate Test Procedure 

Validation Study Report of e-sens, Inc. 

Automated Micro Chlorine Detection 

(AMCD) Method for the Determination of 

Residual Free and Total Chlorine in 

Water. December 2023. (Available at 

https://www.regulations.gov; docket ID 

No. EPA–HQ–OW–2024–0603.) 

List of Subjects in 40 CFR Part 141 

Environmental protection, Chemicals, 

Indians-lands, Intergovernmental 

relations, Reporting and recordkeeping 

requirements, Water supply. 

Jennifer L. McLain, 

Director, Office of Ground Water and Drinking 

Water. 

For the reasons stated in the 

preamble, the Environmental Protection 

Agency amends 40 CFR part 141 as 

follows: 

PART 141—NATIONAL PRIMARY 

DRINKING WATER REGULATIONS 

■ 1. The authority citation for part 141 

continues to read as follows: 

Authority: 42 U.S.C. 300f, 300g–1, 300g–2, 

300g–3, 300g–4, 300g–5, 300g–6, 300j–4, 

300j–9, and 300j–11. 

■ 2. Amend Appendix A to subpart C of 

Part 141 by: 

■ a. In the table entitled ‘‘Alternative 

Testing Methods for Contaminants 

Listed at 40 CFR 141.74(a)(2)’’ revise the 

entries for ‘‘Free Chlorine’’ and ‘‘Total 

Chlorine’’; 

■ b. In the table entitled ‘‘Alternative 

Testing Methods for Contaminants 

Listed at 40 CFR 141.131(c)(1)’’ revise 

the entries for ‘‘Free Chlorine’’ and 

‘‘Total Chlorine’’; 

■ c. Add the table entitled ‘‘Alternative 

Testing Methods for Contaminants 

Listed at 40 CFR 141.901(b)(1)’’ after the 

table entitled ‘‘Alternative Testing 

Methods for Contaminants Listed at 40 

CFR 141.852(a)(5)’’ and before the table 

entitled ‘‘Alternative Testing Methods 

for Contaminants Listed at 40 CFR 

143.4(b)’’; 

■ d. Add footnotes 69 and 70. 

The revisions and additions read as 

follows: 

Appendix A to Subpart C of Part 141— 

Alternative Testing Methods Approved 

for Analyses Under the Safe Drinking 

Water Act 

* * * * * 

ALTERNATIVE TESTING METHODS FOR DISINFECTANT RESIDUALS LISTED AT 40 CFR 141.74(a)(2) 

Residual Methodology EPA methods SM 21st edition 1

SM 22nd edition,28

SM 23rd Edition,49

SM 24th edition 66

ASTM 4 Other 

Free Chlorine ........... Amperometric Titration .......... ................................ 4500-Cl D .............. 4500-Cl D .............. D 1253-08, -14.

DPD Ferrous Titrimetric ......... ................................ 4500-Cl F ............... 4500-Cl F.

DPD Colorimetric ................... ................................ 4500-Cl G .............. 4500-Cl G .............. ................................ Hach Method 

10260.31

Indophenol Colorimetric ......... ................................ ................................ ................................ ................................ Hach Method 

10241.34

Syringaldazine (FACTS) ........ ................................ 4500-Cl H .............. 4500-Cl H.

On-line Chlorine Analyzer ...... EPA 334.0 16.


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Federal Register / Vol. 90, No. 10 / Thursday, January 16, 2025 / Rules and Regulations 4661 

ALTERNATIVE TESTING METHODS FOR DISINFECTANT RESIDUALS LISTED AT 40 CFR 141.74(a)(2)—Continued 

Residual Methodology EPA methods SM 21st edition 1

SM 22nd edition,28

SM 23rd Edition,49

SM 24th edition 66

ASTM 4 Other 

Amperometric Sensor ............ ................................ ................................ ................................ ................................ ChloroSense,17

ChloroSense, 

Rev. 1.1,59 esens AMCD 

Method.69

Total Chlorine .......... Amperometric Titration .......... ................................ 4500-Cl D .............. 4500-Cl D .............. D 1253-08, -14.

Amperometric Titration (Low 

level measurement).

................................ 4500-Cl E ............... 4500-Cl E.

DPD Ferrous Titrimetric ......... ................................ 4500-Cl F ............... 4500-Cl F.

DPD Colorimetric ................... ................................ 4500-Cl G .............. 4500-Cl G .............. ................................ Hach Method 

10260.31

Indophenol Colorimetric ......... 127 55.

Iodometric Electrode .............. ................................ 4500-Cl I ................ 4500-Cl I.

On-line Chlorine Analyzer ...... EPA 334.0 16.

Amperometric Sensor ............ ................................ ................................ ................................ ................................ ChloroSense,17

ChloroSense, 

Rev. 1.1,59 esens AMCD 

Method.69

* * * * * * * 

ALTERNATIVE TESTING METHODS FOR DISINFECTANT RESIDUALS LISTED AT 40 CFR 141.131(c)(1) 

Residual Methodology SM 21st edition 1

SM 22nd edition,28

SM 23rd Edition,49

SM 24th edition 66

ASTM 4 Other 

Free Chlorine .................... Amperometric Titration ... 4500-Cl D ....................... 4500-Cl D ....................... D 1253-08, –14.

DPD Ferrous Titrimetric 4500-Cl F ........................ 4500-Cl F.

DPD Colorimetric ............ 4500-Cl G ....................... 4500-Cl G ....................... ......................................... Hach Method 10260.31

Indophenol Colorimetric ......................................... ......................................... ......................................... Hach Method 10241.34

Syringaldazine (FACTS) 4500-Cl H ....................... 4500-Cl H.

Amperometric Sensor ..... ......................................... ......................................... ......................................... ChloroSense,17

ChloroSense, Rev. 

1.1,59 e-sens AMCD 

Method.69

On-line Chlorine Analyzer.......................................... ......................................... ......................................... EPA 334.0.16

* * * * * * * 

Total Chlorine ................... Amperometric Titration ... 4500-Cl D ....................... 4500-Cl D ....................... D 1253-08, -14.

Low level Amperometric 

Titration.

4500-Cl E ....................... 4500-Cl E.

DPD Ferrous Titrimetric 4500-Cl F ........................ 4500-Cl F.

DPD Colorimetric ............ 4500-Cl G ....................... 4500-Cl G ....................... ......................................... Hach Method 10260.31

Iodometric Electrode ...... 4500-Cl I ......................... 4500-Cl I.

Amperometric Sensor ..... ......................................... ......................................... ......................................... ChloroSense,17

ChloroSense, Rev. 

1.1,59 e-sens AMCD 

Method.69

On-line Chlorine Analyzer.......................................... ......................................... ......................................... EPA 334.0.16

* * * * * * * 

ALTERNATIVE TESTING METHODS FOR INTIAL MONITORING ONLY OF CONTAMINANTS LISTED AT 40 CFR 141.901(b)(1) 

Contaminant Methodology EPA method 

Perfluorobutane Sulfonate (PFBS) .......................................................... SPE LC–MS/MS ............................ 537.1, version 1.0.70

Perfluorohexane Sulfonate (PFHxS) ....................................................... SPE LC–MS/MS ............................ 537.1, version 1.0.70

Perfluorononanoate (PFNA) .................................................................... SPE LC–MS/MS ............................ 537.1, version 1.0.70

Perfluorooctanesulfonic Acid (PFOS) ..................................................... SPE LC–MS/MS ............................ 537.1, version 1.0.70

Perfluorooctanoic Acid (PFOA) ............................................................... SPE LC–MS/MS ............................ 537.1, version 1.0.70

2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy)propanoate (HFPO–DA or 

GenX Chemicals).

SPE LC–MS/MS ............................ 537.1, version 1.0.70

1Standard Methods for the Examination of Water and Wastewater, 21st edition (2005). Available from American Public Health Association, 800 

I Street NW, Washington, DC 20001–3710. 

* * * * * * * 4Available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428–2959 or http://astm.org. The methods listed are 

the only alternative versions that may be used. 

* * * * * * * 16EPA Method 334.0. ‘‘Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer,’’ September 2009. EPA 815– 

B–09–013. Available at https://www.nemi.gov. 


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4662 Federal Register / Vol. 90, No. 10 / Thursday, January 16, 2025 / Rules and Regulations 

17 ChloroSense. ‘‘Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,’’ August 2009. Available at https://

www.nemi.gov or from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018. 

* * * * * * * 28Standard Methods for the Examination of Water and Wastewater, 22nd edition (2012). Available from American Public Health Association, 

800 I Street NW, Washington, DC 20001–3710. 

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

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

* * * * * * * 49Standard Methods for the Examination of Water and Wastewater, 23rd edition (2017). Available from American Public Health Association, 

800 I Street NW, Washington, DC 20001–3710. 

******* 55EPA Method 127. ‘‘Determination of Monochloramine Concentration in Drinking Water.’’ January 2021. EPA 815–B–21–004. Available at the 

National Service Center for Environmental Publications at https://www.epa.gov/nscep. 

******* 59 ChloroSense, Rev. 1.1. ‘‘Free and Total Chlorine in Drinking Water by Amperometry using Disposable Sensors.’’ February 2020. Palintest 

Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401. 

* * * * * * * 66Standard Methods for the Examination of Water and Wastewater, 24th edition (2023). Available from American Public Health Association, 

800 I Street NW, Washington, DC 20001–3710. 

******* 69 e-sens, Inc. ‘‘e-sens, Inc. Automated Micro Chlorine Detection (AMCD) Method for the Determination of Residual Free and Total Chlorine in 

Water.’’ December 2023. Available from e-sens, Inc., 630 Komas Dr., Ste 235, Salt Lake City, Utah 84108. 70EPA Method 537.1, Version 1.0. ‘‘Determination of Selected Per- and Polyfluorinated Alkyl Substances (PFAS) in Drinking Water by Solid 

Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS).’’ November 2018. EPA/600/R–18/352. Approved as alternative testing method to support initial PFAS monitoring (for monitoring-frequency determinations) until April 26, 2027 as described at 40 CFR 

141.902(b)(1) [Monitoring requirements for PFAS—Initial monitoring]. Available at the National Service Center for Environmental Publications at 

https://www.epa.gov/nscep. 

[FR Doc. 2025–00464 Filed 1–15–25; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF HEALTH AND 

HUMAN SERVICES 

42 CFR Chapter 1 

Mandatory Guidelines for Federal 

Workplace Drug Testing Programs— 

Authorized Testing Panels 

AGENCY: Substance Abuse and Mental 

Health Services Administration 

(SAMHSA), Department of Health and 

Human Services (HHS) 

ACTION: Issuance of authorized drug 

testing panels. 

SUMMARY: The Department of Health and 

Human Services (‘‘HHS’’ or 

‘‘Department’’) herein publishes the 

panels of Schedule I and II drugs and 

biomarkers authorized for testing in 

Federal workplace drug testing 

programs. The Department has revised 

the drug testing panels for both urine 

and oral fluid, and revised required 

nomenclature for laboratory and 

Medical Review Officer Reports. 

DATES: The authorized drug testing 

panels and required report 

nomenclature are effective July 7, 2025. 

FOR FURTHER INFORMATION CONTACT: 

Eugene D. Hayes, Ph.D., MBA, 

SAMHSA, CSAP, DWP; 5600 Fishers 

Lane, Room 16N02, Rockville, MD 

20857, by telephone (240) 276–1459 or 

by email at Eugene.Hayes@

samhsa.hhs.gov. 

SUPPLEMENTARY INFORMATION: The drug 

testing panels in this Notification 

specify the analytes and cutoffs for 

Federal agency workplace drug testing 

specimens and the nomenclature (i.e., 

analyte names and abbreviations) that 

must be used to report Federal 

workplace drug test results, in 

accordance with Subpart C of the 

Mandatory Guidelines for Federal 

Workplace Drug Testing Programs using 

Urine (UrMG, 88 FR 70768) and the 

Mandatory Guidelines for Federal 

Workplace Drug Testing Programs using 

Oral Fluid (OFMG, 88 FR 70814). 

Section 3.4 of Subpart C calls upon the 

Secretary of HHS (Secretary) to ‘‘publish 

the drug and biomarker test analytes 

and cutoffs (i.e., the ‘drug testing panel’ 

and ‘biomarker testing panel’) for initial 

and confirmatory drug and biomarker 

tests in the Federal Register each year,’’ 

and make them available on the internet 

at http://www.samhsa.gov/workplace. 

Section 3.4 of the UrMG and the OFMG 

also requires HHS-certified laboratories, 

instrumented initial test facilities (IITFs, 

urine only), and Medical Review 

Officers (MROs) to use the 

nomenclature (i.e., analyte names and 

abbreviations) published with the drug 

and biomarker testing panels to report 

Federal workplace drug test results. 

This Federal Register Notification 

(FRN) contains only the drug testing 

panel because, to date, HHS has not 

approved any biomarker tests for use 

with Federal workplace drug testing 

specimens. The drug testing panels in 

Section 3.4 of the UrMG and OFMG will 

remain in effect until July 7, 2025. 

Background 

HHS, by the authority of section 503 

of Public Law 100–71, 5 U.S.C., and 

Executive Order 12564, establishes the 

scientific and technical guidelines for 

Federal workplace drug testing 

programs and establishes standards for 

certification of laboratories engaged in 

drug testing for Federal agencies. In 

addition, the Department specifies the 

drugs and biomarkers for which Federal 

employees may be tested. To facilitate 

timely analyte and cutoff changes based 

on the state of the science, the 

Department publishes the HHS 

authorized drug and biomarker testing 

panels separately from the Mandatory 

Guidelines. 

Analyte changes are based on a 

thorough review of relevant 

information, including drug prevalence 

estimates, the current state of the 

science, laboratory capabilities, costs 

associated with the change, and benefits 

of the change to Federal agencies. To 

identify panel changes needed, the 

Department solicits review and input 

from subject matter experts such as 

Responsible Persons (RPs) of HHScertified laboratories, Medical Review 

Officers (MROs), research scientists, and 

manufacturers of collection devices 

and/or immunoassay kits, as well as 

Federal partners such as the Department 

of Transportation (DOT), the Food and 

Drug Administration (FDA), the 

Department of Defense (DOD), and the 

Drug Enforcement Administration 

(DEA). The Department also seeks 

public comment to inform decisions 

related to analyte changes. 


ddrumheller on DSK120RN23PROD with RULES1