EPA Approves Alternative Methods for PFAS Rule Initial Monitoring and Chlorine Testing

On January 16, 2025, EPA published a Federal Register (FR) Notice for an, “Expedited Approval of Alternative Test Procedures for the Analysis of Contaminants Under the Safe Drinking Water Act; Analysis and Sampling Procedures.” EPA used its streamlined approval authority to make these two alternative methods available under the Safe Drinking Water Act (SDWA), that are determined to be as effective as the methods already established in the regulations for the same contaminants.

• PFAS Rule Initial Monitoring: Effective this day, EPA expedited approval of EPA Method 537.1, version 1.0 for initial monitoring under the PFAS National Primary Drinking Water Regulation (NPDWR). This change addresses the timing gap between the date of January 1, 2019, in the rule that allows use of water system samples for initial monitoring, and when the current methods in the rule became available. The current methods in the rule are EPA Method 533 (published in December 2019) and EPA Method 537.1, version 2 (published in March 2020). Approving this method allows water systems to use samples analyzed using Method 537.1, version 1.0 for PFAS NPDWR initial monitoring beginning January 1, 2019.
• Chlorine Testing: The second approval in the FR Notice is for using the e-sens Automated Micro Chlorine Detection (AMCD) method to determine free and total chlorine in drinking water. The approval of this vendor developed method increases the number of methods that can be used for chlorine sample analysis and can help reduce monitoring costs for water systems.

For more information, view the EPA Fact Sheet, read the FR Notice, and visit EPA’s website.