The Barnstable County government meeting held on August 1, 2025, focused on the ongoing PFAS remediation efforts at the former fire training facility. The primary agenda item was the update on the implementation of a permeable reactive barrier (PRB) designed to mitigate PFAS contamination in groundwater.

The meeting began with a detailed explanation of the PRB's design and function. The PRB will utilize colloidal activated carbon, similar to the granular activated carbon currently used for wellhead treatment. This carbon will be injected into the subsurface to create a vertical treatment wall that captures contaminants as groundwater flows through it. The geological characteristics of the site, particularly the presence of a silty clay layer, are crucial for the PRB's effectiveness.

Earlier this year, a geophysical survey confirmed the continuity of the silty clay layer, which is essential for the PRB's design. A pilot test was conducted in late October 2024, where approximately 24,000 pounds of colloidal activated carbon were injected into a targeted area with high PFAS concentrations. Monitoring results showed a significant decline in PFAS levels, with concentrations dropping below regulatory criteria in subsequent months.

Following the successful pilot test, the county moved forward with plans for a full-scale PRB. A request for proposals was issued, and Regenesis was selected as the contractor based on their experience and competitive bid. The full-scale implementation plan was submitted to the Massachusetts Department of Environmental Protection (DEP) and received conditional approval.

The PRB will consist of approximately 250 injection points along the eastern and southern boundaries of the site, with a total of 590,000 gallons of carbon to be injected. The injection process began in late July and is expected to take about 12 weeks to complete.

In addition to the PRB, a secondary groundwater extraction system is in place to treat contaminated water. However, the system recently experienced vandalism, leading to temporary shutdowns. Repairs are underway, and the system is awaiting inspection before being reactivated.

The meeting concluded with a commitment to continue monitoring groundwater quality and evaluating the effectiveness of the PRB in reducing PFAS levels. The county remains focused on ensuring compliance with environmental standards and protecting public health.