Residents in the northwest part of Harvard whose wells were found to be contaminated with per- and polyfluoroalkyl substances (PFAS) two years ago may be one step closer to knowing where those substances came from.
At the Restoration Advisory Board meeting at Devens on Nov. 10, Army contractors reported that one of the board’s current concerns is whether PFAS in the groundwater under the former Fort Devens migrated to some private wells in Harvard. The board meets quarterly to inform the public of the Army’s ongoing work to address the environmental damage done at Fort Devens before it closed in 1996.
At the request of Harvard’s Board of Health, the Army tested 125 private wells in northwest Harvard in 2020 and found PFAS in 73 of them. Eighteen of those wells tested over 20 parts per trillion (ppt), which is the state’s maximum contaminant level for the sum of six specific compounds. Two of those compounds, PFOA and PFOS, accounted for most of the PFAS in Harvard’s wells. Drinking water from public water supplies and private wells that are either new or are on a property to be sold cannot exceed the state’s defined maximum levels for a list of specific toxic substances. PFAS were added to that list in 2019. The 18 wells that exceeded the maximum in the 2020 tests were on Blanchard Road (11), Lancaster County Road (3), Ayer Road near the rotary (3), and Depot Road (1).
A few years ago, contractors studying PFAS contamination at the former Fort Devens reported that groundwater from three “areas of concern,” or AOCs, flowed into Cold Spring Brook, which runs along the Devens and northwest boundary of Harvard. Levels of the compounds PFOA and PFOS are very high in the groundwater under those three contamination areas.
One of the monitoring wells in AOC 57, the site of a fuel oil spill in 1977, showed a level of 4,390 ppt for the two compounds in 2019. Wells in AOC 74, a former firefighting training site, and AOC 75, the site of a warehouse fire, showed levels of 2,270 ppt and 1,400 ppt, respectively, that same year. Before they stopped being manufactured in 2002, firefighting foams containing PFAS were used to extinguish fires of liquids such as gasoline and oil.
Since the wells were tested in 2020, little has been done to identify the source of northwest Harvard’s PFAS contamination, but information presented by SERES/Arcadis contractor Andy Vitolins at the Nov. 10 meeting indicated that may be about to change. The latest focus of the PFAS remedial investigation on the east side of Devens is on PFAS discharge from groundwater to bodies of surface water and the potential for its migration beyond those bodies of water. Cold Spring Brook was identified as one of the areas to be studied. Vitolins said his company will be “looking to see if groundwater coming from Devens is going beyond Cold Spring Brook,” and if Devens could be the source of PFAS in private wells in northwest Harvard.
This phase of the investigation will also include studying whether PFAS in the groundwater at the former firefighting training area at what was Moore Army Airfield on the north side of Devens is discharging into the Nashua River. The first round of testing was completed in September, but Vitolins said results were not yet available. He said lab result turnaround times for PFAS tests have recently quadrupled. New testing protocols require detecting lower levels and more compounds, and PFAS investigations are increasing, creating more work than labs can handle.
The next meeting of the Restoration Advisory Board is scheduled for Feb. 9, 2023. More information on the board and the environmental cleanup at Devens is available at www.nae.usace.army.mil/missions/projects-topics/former-fort-devens-environmental-cleanup.
