New Nantucket PFAS Detections "Extremely Concerning"

The town has revealed that recent water testing around the island has uncovered "extremely concerning" detections of the so-called "forever chemicals" known as PFAS at private wells on Nantucket, including one sample that was so high it is considered an "imminent hazard" by the state.

The latest detections were revealed through a Massachusetts Department of Environmental Protection investigation and announced during the Nantucket Board of Health's meeting on Thursday.

"I have some very important news to share, and that is we got a detection above the imminent hazard threshold near the intersection of Hummock Pond Road and Burnt Swamp (Lane)," Andrew Shapero, the town's new environmental contamination administrator, told the Board of Health on Thursday. "This was identified by a Mass DEP source discovery investigation when they were on the island on April 9th. (That is) An extremely concerning concentration to see in drinking water. In addition to that, we got one more detect above the 20 nanogram per liter state standard on Nobska Way."

In Massachusetts, the Department of Environmental Protection has set the public drinking water standard, also called the Massachusetts Maximum Contaminant Level (MCL), at 20 nanograms per liter (ng/L), or parts per trillion (PPT). The detection at Hummock Pond Road and Burnt Swamp Lane was 124 nanograms per liter (ng/L), more than six times the state's threshold for safe drinking water.

Those detections were outside of the previously known PFAS contamination hotspots near Nantucket Memorial Airport and Toms Way in the mid-island area.

Used to manufacture stain- and water-resistant products, the family of chemicals known as PFAS is suspected to increase the risk of kidney and testicular cancers, as well as other health conditions. They are often called "forever chemicals" because they do not break down and remain present in the environment. The chemicals are used in a wide range of products, from non-stick pans to fast food wrappers to firefighting foam.

In addition to the testing results announced from the Mass DEP investigation, Shapero also revealed the results from 22 samples from the town's voluntary and private well regulation sampling. There were two additional detections above the 20 nanogram per liter threshold from those testing results, including one off Old South Road near the airport, and another on Surfside Road near Miacomet.

Shapero told the Board of Health that the "imminent hazard" detection at Hummock Pond and Burnt Swamp prompted the town to notify abutters within 500 feet to advise them of the test results and provide them options to conduct their own sampling. The property would be able to connect to town water, he said. 

The town is already addressing PFAS contamination near the airport and in the area of Toms Way, the small dirt road located across the street from the Wannacomet Water Company's Wyer's Valley pumping stations. The underground plume of PFAS has prompted the town to begin the installation of a new treatment system.

The source of the PFAS contamination at Toms Way, where "staggering" levels of PFAS were discovered in residents' private drinking wells in September 2023, is still unknown. The island residents who were impacted filed a class action lawsuit against the manufacturers and suppliers of PFAS, and the town paid to connect the affected properties to the municipal water supply. Meanwhile, the Massachusetts Department of Environmental Protection launched an investigation of the nearby Fairgrounds Road municipal campus (the site of the former Nantucket Electric Company) as a potential source contributing to high levels of PFAS on Toms Way. The state agency began drilling 12 monitoring wells late last year, and during a January 2025 Board of Health meeting, the town's special projects manager, Chuck Larson, shared groundwater testing results from samples taken in December. Nine of the 12 wells showed hits for PFAS6, with levels between 4.9 and 22.3 PPT.

The town and Nantucket Memorial Airport previously filed a similar lawsuit against a group of chemical companies involved in the manufacturing of PFAS related to the contamination of properties around the airport. That legal action was filed back in 2021 following the discovery of PFAS exposure believed to be the result of AFFF that was released during drills required by the Federal Aviation Administration.