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Summary of PFAS sampling for Maine public water systems Maine CDC Drinking Water Program October 2019 This document presents a preliminary DRAFT summary of the 2019 voluntary sampling program for per- and polyfluoroalkyl substances (PFAS) in public water systems in Maine. The sampling program was coordinated by the Maine Center for Disease Control & Prevention (CDC) Drinking Water Program (DWP). The DWP designed this voluntary sampling program based on currently known or suspected sources of
- PFAS. The 2019 sampling round follows two previous programs in Maine, including the Unregulated
Contaminants Monitoring Rule (UCMR) sampling of 17 system conducted by the US Environmental Protection Agency (EPA) between 2013 and 2015 and a DWP-initiated voluntary sampling program that included 17 systems in 2017. The objective of the 2019 sampling program was to further refine our understanding of potential PFAS impacts to public drinking water supplies in Maine. PFAS are not regulated under the Safe Drinking Water Act (SDWA) and therefore have no federally-established Maximum Contaminant Level (MCL) that would require action such as treatment to remove these compounds from drinking water. EPA has established a Health Advisory of 70 parts per trillion (ppt), combined, for two PFAS compounds: perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). For the 2019 sampling program, a total of 36 public water systems were identified as having potential risk factors for impacts from PFAS. Risk factors included the following:
- proximity to airports;
- proximity to known use of firefighting foam;
- nearby landfills;
- papermill activity;
- septic leach fields within 100 feet of a school well source; and
- proximity to biosolids processing facilities or documented sludge spreading operations.
Sampling was conducted by an independent contractor, Sevee & Maher Engineers, Inc. (SME) of Cumberland, Maine according to currently accepted best practices for PFAS sample collection. Samples were analyzed using EPA Method 537.1 by Alpha Analytical, Inc. laboratory in Portsmouth, NH. An unanticipated outcome of the 2019 sampling program was that out of the 36 systems selected for sampling, 17 public water systems declined to participate. Although there was no cost to the systems, we can assume that these water systems were concerned about potential costs or other challenges that may have resulted from finding PFAS in their water supply. Of the 19 systems sampled for PFAS in 2019, nine (9) were found to have measurable detections of PFAS. However, there were no detections of PFOA and PFOS in exceedance of the current EPA Health Advisory
- f 70 parts per trillion (ppt) combined. In addition, the highest levels of PFOA and PFOS measured as