GZA advances PFAS assessment and remediation at former Hyannis fire training site
GZA GeoEnvironmental Inc. has been selected by Barnstable County to lead PFAS investigation and remediation efforts at a former municipal fire training facility in Hyannis, Massachusetts, where decades of aqueous film-forming foam (AFFF) use contributed to contamination concerns.
The approximately six-acre site, located in the Town of Barnstable’s Hyannis village, was used for firefighter training from 1956 to 2019, including roughly 40 years of AFFF use. These foams contained per- and polyfluoroalkyl substances (PFAS), which have been linked to persistent environmental contamination. AFFF training activities at the site ended in 2013.
GZA is conducting a comprehensive Phase II Site Assessment to evaluate the nature and extent of PFAS contamination. The work includes hydrogeologic investigations, groundwater sampling, and evaluation of remediation strategies.
As part of the response, a colloidal activated carbon (CAC) permeable reactive barrier (PRB) was piloted and later installed at full scale in late 2025 to limit further migration of PFAS in groundwater.
“GZA’s data-driven and technical approach has helped us better understand the complexity of the site and surrounding groundwater conditions, and identify effective, cost-conscious remediation strategies,” said Barnstable County Administrator Michael Dutton in a press release. “Based on their recommendations, a permeable reactive barrier was installed downgradient of the facility in October 2025. Early monitoring results are encouraging and indicate the system is performing as intended.”
In addition to technical work, GZA is coordinating public engagement efforts, including meetings with residents and stakeholders to provide updates and address concerns related to the site.
“Identifying, mitigating, and neutralizing the risks posed by the ‘forever chemicals’ known as PFAS is a major focus of GZA’s engineers and environmental professionals,” said GZA President and CEO Patrick Sheehan in a press release. “We look forward to continuing to work closely with the Barnstable County government and our partners to support the County in its efforts to investigate and remediate the former Municipal Fire Training Facility and protect the municipal water supplies and public health of Barnstable and Cape Cod.”
The project reflects a broader national effort to address PFAS contamination at legacy fire training sites, where AFFF use has been a primary source of groundwater impacts.