Abstract
<jats:p>In 2016, the State of Maine became aware of PFAS contamination in a drinking water well in West Kennebunk1, Maine. Since then, significant PFAS contamination of drinking water wells in Maine has been discovered through the “PFAS Soil and Groundwater Investigation at Sludge and Septage Land Application Sites”3, completed by the Maine Department of Environmental Protection (MEDEP). The MEDEP has been taking PFAS samples in drinking water wells near sludge and septage sites since January of 20176. In the fall of 2025, I discussed with the MEDEP the possibility of evaluating statewide PFAS sample data to date, to look for PFAS contamination trends in PFAS contaminated drinking water wells. With thorough supportive assistance from the MEDEP, in late 2025 and early 2026 I received spreadsheet data of PFAS sample test results for all samples taken by the MEDEP or their contractors around sludge and septage land application sites (~220,000 PFAS parameter test results)4. All of the samples were taken from drinking water wells throughout Maine4. This report describes the methodology used to identify trends in PFAS concentration in drinking water wells throughout the State of Maine over a five-year period: 2021-2025. Results include: Trend graphs for PFAS 6 and PFOS independently, for 99 and 126 wells respectfully, that had sample results in each of those five years. The percentage of those wells with increasing trends of PFAS6 or PFOS concentration over the five-year period 2021-2025. Graphs showing PFAS trends for a subset of those wells with at least one sample over 1000 ppt (parts per trillion) PFAS 6 or PFOS, and for the subset of wells with at least one sample over 10,000 ppt PFAS 6 or PFOS. Conclusions and Recommendations are included. </jats:p>