On April 16, 2024, EPA promulgated a rule that updates its list of approved methods for measuring pollutants in wastewater and waterbodies under the Clean Water Act (CWA) (see Federal Register notice for the final Methods Update Rule). Industrial facilities, municipal wastewater treatment plants, and state governments use approved methods to identify the types and amounts of pollutants regulated under the CWA. This action adds new methods to Part 136 of Title 40 of the Code of Federal Regulations (CFR) and makes minor editorial or procedural changes to some existing methods that are already promulgated in 40 CFR Part 136.
How does this action help the regulated community?
Often, regulated entities have a choice in deciding which approved method they will use to measure a pollutant because more than one approved method is available under 40 CFR Part 136. This rulemaking increases flexibility by providing additional methods from which to select. New methods added under the Alternate Test Procedure (ATP) program reflect innovative technologies that are cheaper, faster, or greener than the other approved methods for that same parameter. This rule imposes no regulatory requirements or costs on any person or entity. The use of alternate methods is voluntary.
Is EPA required to establish analytical methods?
Yes, CWA Section 304(h) requires EPA to establish analytical methods to measure pollutants in NPDES permit applications and for reports required under NPDES permits. These CWA methods are found in 40 CFR Part 136 and are used to implement the NPDES program. This action proposes minor updates to 40 CFR Part 136.
What would EPA’s updates change?
The proposed changes are minor technical changes and clarifications to improve existing methods, new and/or revised methods published by voluntary consensus standard bodies (such as ASTM International and the Standard Methods Committee) that EPA seeks to publish in Part 136, and methods EPA has reviewed under its ATP program and found to be comparable to one or more methods currently in Part 136.
Where can I find more information?
You can view the Federal Register notice and supporting documents for the proposed rule at http://www.regulations.gov under Docket ID: EPA-HQ-OW-2022-0901. EPA has also provided a link to the Federal Register on the Clean Water Act Analytical Methods website at: https://www.epa.gov/cwa-methods
