
Office of Water
EPA 821 F 21 002
March 2021
Final Clean Water Act Methods Update Rule for the Analysis of Effluent
Summary
EPA finalized specific changes to analytical test procedures that are used by industries and municipalities to analyze the chemical, physical, and biological components of wastewater and other environmental samples that are required by regulations under the Clean Water Act. The changes include:
revised EPA methods;
new and revised methods published by voluntary consensus standard bodies, such as ASTM International and the Standard Methods Committee;
new and updated methods developed by the U.S. Geological Survey; 
methods reviewed under the Alternate Test Procedures (ATP) program; and 
minor changes to quality assurance and quality control within individual methods.
Background
EPA approves analytical methods for measuring regulated pollutants in wastewater, as contained in the Code of Federal Regulations (CFR), Title 40 Part 136. The regulated community and laboratories use these approved methods for determining compliance with National Pollutant Discharge Elimination System (NPDES) permits or other monitoring requirements. Often, these entities have a choice in deciding which approved method they will use to measure a pollutant because more than one approved method is available. 
To promote method innovation, the EPA also maintains a program whereby method developers may apply for an EPA review and potentially for approval of ATPs. This ATP program is described for Clean Water Act applications at 40 CFR Parts 136.4 and 136.5.
Periodically, EPA updates the approved test procedures in 40 CFR Part 136.
What would EPA's finalized rule change?
The finalized rule changes provide increased flexibility to the regulated community, improve data quality, and update Clean Water Act methods to keep current with technology advances. 
Also, in an effort to approve methods more quickly, this rule is limited to minor procedural or editorial changes that do not affect the performance of the methods.
Where can I find more information?
You can view the Federal Register notice for this proposed rule online at www.regulations.gov under Docket ID: EPA- EPA-HQ-OW-2018-0826. EPA will also provide a link to the Federal Register notice on our Clean Water Act Methods website. 
You may also contact Meghan Hessenauer by phone at 202-566-1040 or by email at hessenauer.meghan@epa.gov.
