Environmental contamination administrator reports MassDEP source‑discovery results: 63% detect rate, nine imminent‑hazard wells on Tom’s Way cluster

Andrew Shapiro, Nantucket’s environmental contamination administrator, gave an expanded PFAS update that incorporated MassDEP’s recent source‑discovery sampling, local voluntary testing and a new Verdantas field investigation summary for the Fairgrounds site.

Shapiro said MassDEP evaluated 86 properties as part of its source‑discovery investigation and found PFAS detects at 63% of those parcels. He said 23 properties exceeded Massachusetts’ PFAS‑6 standard (20 nanograms per liter [ng/L], or parts per trillion), and identified nine properties — clustered on Tom’s Way and adjacent streets — that exceeded the state’s imminent‑hazard level of 90 ng/L. The maximum concentration reported in MassDEP data was 787 ng/L at a Tom’s Way location.

Shapiro stressed he tabulated MassDEP findings at the parcel level for clarity: some properties had multiple samples (initial, duplicates, post‑treatment and confirmatory results) so counts summarize by property, not by sample. The MassDEP data generally show higher rates and higher…