The island community teamed with CDM Smith experts to evaluate potential sources of PFAS contamination. Nantucket is moving toward better informed PFAS reduction and control strategies in the sewer collection system, wastewater treatment plant and landfill operations, while providing public water to impacted residents when possible. 

The invisible threat surfaces

The regulations landed in October 2020. Massachusetts set enforceable drinking water standards for six PFAS compounds: PFOS, PFOA, PFHxS, PFNA, PFHpA and PFDA: so-called “forever chemicals” that don’t break down in the environment. On Nantucket, officials knew what those standards meant. The airport had been required to use PFAS-laden firefighting foam for decades, and preliminary tests had been showing concerning signs for months.

The contamination wasn’t coming from just one place. Airport firefighting foam was a known culprit, but PFAS compounds were also appearing in wastewater treatment residuals, landfill leachate and domestic wells. Even the island’s composting program had unknowingly become a PFAS transmitter. “For decades, manufacturers produced everyday products with PFAS, while communities like this island were exposed without knowing it,” explains PFAS communications specialist Rose Hanson.