Barnstable County update: permeable reactive barrier installed, early PFAS drops reported at former fire training site

Paul Rezula, the Cape Cod regional government’s assets and infrastructure manager, told the Assembly of Delegates on March 18 that a permeable reactive barrier (PRB) installed in October 2025 has produced early reductions in measured PFAS concentrations at the county-owned former municipal fire training site.

Rezula said the roughly five-acre site south of Route 6 and north of the Cape Cod Gateway Airport was used for decades by local and regional fire departments and that many users historically applied aqueous film‑forming foams (AFFF) that contained PFAS. "Once the county learned of the dangers and hazards of PFAS ... we stopped exercises, including any kind of water training," Rezula said, describing work to cap portions of the property and to install a groundwater pump-and-treat system that first went online in July 2015.

The presentation summarized past response steps: roughly 200 tons of PFAS‑affected soil was removed in January 2017; a 4,000-square-foot cap was placed in December 2018; the burn building was demolished in 2021; and the PRB — a colloidal activated carbon curtain installed via 247 injection points — was placed to intercept downgradient groundwater moving toward Mary Dunn Pond and the Mary Dunn public water supply wells. Rezula said monitoring charts show concentrations dropping since the barrier was installed. "In the short time the PFAS barrier has been installed, it's dramatically decreasing the PFAS numbers," he said.

Rezula framed the work as a multi‑phase program: an immediate response phase, a plume‑delineation phase (phase 2), and subsequent remediation alternatives and implementation phases. He said GZA GeoEnvironmental is the county’s licensed site professional and that its work includes installing clusters of shallow, medium and deep wells, compiling historic samples, and producing a final report to be reviewed by MassDEP and released for public comment.

On funding, Rezula said the county used $4,000,000 in American Rescue Plan Act (ARPA) funds to install the PRB and has been notified of an additional $3,000,000 in state-directed funds for further work. He also cited the Massachusetts Clean State Water revolving fund, MassDEP brownfields programs and a potential manufacturer settlement as other possible revenue avenues. Rezula noted a 2017 settlement to support filtration tied to the Mary Dunn wells totaling $8,320,000 over 20 years to cover drinking-water filtration operations and maintenance.

County Administrator Michael Dutton told delegates the county is the property owner and therefore the primary responsible party under the Massachusetts Contingency Plan process and that the county has consulted special counsel about cost recovery. "We are responsible ... as the owner of the property," Dutton said, but he added that the county will continue investigating historic users and pursue contributions or federal/grant funding rather than initiating widespread litigation if practical.

Delegates pressed for details. Delegate Gallagher asked whether images or slides were AI generated after noticing an "AI content" watermark; Rezula responded that the photos were taken on the site by GZA or county staff and represented field work. Delegate O'Malley asked whether the county has data on foam use before ownership transferred from the Hyannis Fire District in the 1980s; Rezula said deeds show a transfer but records of foam use are limited and that historical interviews and photo review are ongoing.

Rezula said preliminary ecological and human‑health assessments indicate the greatest exposure pathway is drinking water and that public wells outfitted with carbon treatment are meeting drinking-water standards. He said phase 2 plume delineation is expected to conclude later this year, after which the county will assess alternative remedies (including possible pump-and-treat modifications) and implement recommendations.

The county said it will submit final technical reports to MassDEP and will release those reports for public comment as part of the MCP process. Next steps specified in the presentation include completing additional well installs, refining the groundwater model with regional partners, and evaluating remediation alternatives in phases 3 and 4.

Impact and next steps: the county continues monitoring the PRB's performance, expects more data to show further reductions over time, and will coordinate with neighboring owners and agencies including the Cape Cod Gateway Airport, Barnstable Water, the Barnstable Water Pollution Control Facility and state regulators on further investigation and funding options.