Summary of PFAS sampling for Maine public water systems Maine CDC - PDF document

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 of 70 parts per trillion (ppt) combined. In addition, the highest levels of PFOA and PFOS measured as individual compounds (10.2 and 5.2 ppt, respectively) are below the levels set recently as State MCLs by the State of New Hampshire (PFOA NH MCL = 12 ppt, PFOS NH MCL = 15 ppt). The remaining 10 public

water systems tested for PFAS had no detections for any of the 18 compounds included in EPA Method 537.1. It is notable that there were no PFAS detections at systems that were selected based on proximity to sludge spreading sites. The following table summarizes detections only for the 2019 PFAS sampling program. Note that out of 18 PFAS compounds analyzed, only seven (7) were detected at any of the water systems included in this program. Table 1 PFAS Detections in Public Water Systems for 2019 Voluntary Sampling Round Maine CDC Drinking Water Program Public Water Potential PFAS Compound Supply Name Source Perfluorooctanesulfonamidoacetic Acid (NETFOSAA) N-Ethyl Perfluorooctane Sulfonamide, N-Ethyl Perfluorooctanesulfonic Acid (PFOS) Perfluorohexane Sulfonate (PFHXS) Perfluoro butane Sulfonate (PFBS) Perfluoroheptanoic Acid (PFHPA) Perfluorohexanoic Acid (PFHXA) Perfluorooctanoic Acid (PFOA) Estes Lake Airport ND 1 ND ND ND 2.22 2 ND ND Mobile Home Park Pine Ridge Fire Fighting Foam ND ND ND ND ND 3.59 ND Hunton Brook Use near well Association Charter Oak Landfill ND ND ND 2.38 ND 3.01 ND Mobile Home Village The Pines at Landfill ND ND ND 2.22 ND 2.65 ND Arundel Mexico Water Aerial Deposition ND ND ND ND ND ND 2.07 District from Papermill AOS 98 Septic leach field 12.1 ND ND ND ND 3.06 ND Georgetown at 100' or less Central School Fayette Septic leach field ND ND ND ND ND 2.06 ND Central School at 100' or less

Pejepscot Septic leach field 2.07 ND 3.17 3.67 5.17 5.1 ND School- at 100' or less Topsham LISBON Superfund Site 3.26 2.69 5.73 4.51 ND 10.2 ND WATER DEPARTMENT 1 ND = Non-Detect, or below the Reporting Limit Required by Method 537.1 2 Values expressed as nanograms per liter or parts per trillion (ppt). The combined sampling efforts mentioned in this document (EPA UCMR in 2013-2015, Maine DWP in 2017 and Maine DWP in 2019) have resulted in analysis of drinking water samples for PFAS concentration in a total of 53 public water systems in Maine. These system represent more than 60% of the population served by Community water systems. Maine has approximately 378 regulated Community water systems (water systems that serve people in their homes on a year-round basis); 375 non-transient non-community system s (these include schools and businesses); 1,151 transient systems (these include restaurants and campgrounds); and 54 regulated bottled water sources. More than half of Maine’s residents are not served by public water systems but instead use private residential wells as their primary drinking water source. Due to the high percentage of public water systems declining to participate in 2019, we are currently discussing whether to perform additional voluntary PFAS sampling or to consider another approach to generate a robust and meaningful dataset. The estimated c ost to sample the remaining Community water systems (approximately 325) would be significant (estimated at $115,500-$231,000) and would likely need to be shared by the water systems and their ratepayers. The attached Appendix contain tables listing all laboratory analytical results generated from DWP’s 2019 voluntary sampling program. Data from previous sampling rounds can be provided upon request. Questions and comments concerning this document can be directed to: Michael Abbott , P.E., C.G. Drinking Water Program Manager 207-287-5684 michael.abbott@maine.gov

APPENDIX A LABORATORY ANALYTICAL DATA SPREADSHEET 2019 PFAS SAMPLING ROUND