In 2019, the State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) issued guidance for PFAS sampling. DDW has released an updated version of the guidance document (ddw_pfas_sampling_guidance_may_2020). A preliminary review indicates several changes in the text throughout the document and the updated version includes the following statement:
“The analytical method used to assess the presence of PFAS in drinking water is EPA Method 537.1 (November 2018). This is the only method acceptable to DDW for drinking water analyses. Use of a laboratory accredited for this method is required for samples to be reported to DDW.”
The enclosed document includes a link to an April 2020 list of laboratories accredited to analyze for PFAS with EPA Method 537.1. The 2019 version of the sampling guidance cited the use of both EPA Method 537.1 and EPA Method 537 rev 1.1.