- PFAS removal filtration
- Iron and manganese filtration
- Pilot testing – activated carbon, ion exchange, and GreensandPlus™
- Water quality analysis
- Basis of design memorandum
- Site design – stormwater, access, security, residual lagoon, infiltration bed, raw and treated water mains, geotechnical investigation
- MassDEP permitting of pilot study, treatment plant design and residuals management plan
- FAA, DOT, MEPA, MESA, local permitting
- Funding application and management
Challenge
The Barnstable Fire District Water Department (BFDWD) Wells #2 and #5 have the highest concentrations of PFAS within the public water system, approaching the Massachusetts maximum contaminant level for a combined concentration of 6 compounds. In addition, more stringent PFAS regulations from the USEPA were anticipated in the future. Iron and manganese concentrations would shorten GAC filter life without removal. Carbon dioxide levels increase caustic potash addition for corrosion control.
Solution
As a short-term measure, the Well #5 discharge has been reduced such that Well #4 and Well #5 blending is optimized to reduce PFAS concentration being sent to water consumers. Also, previously inactive Well 1 (no PFAS presence) was restored to service with a pumping station rehabilitation and a new chemical treatment facility. GZA and its subconsultants proposed to design a PFAS removal treatment plant with iron and manganese removal pretreatment, and air-stripping for carbon dioxide removal. To proceed with the design of the proposed treatment plant, GZA provided oversight to the piloting process and produced a pilot study report for the treatment processes. GZA lead the BFDWD through successful funding at annual District meeting and obtained a O-percent SRF loan for the design costs. GZA’s comprehensive PFAS investigation, design-permitting work and technical leadership guided the client in managing their PFAS contamination.
The treatment plant and site work were designed by GZA and its subconsultants and approved by state and local permitting agencies. The final design of the facility was completed in December 2022.
Benefit
GZA, with its expertise in PFAS investigations and water quality analysis, efficiently guided the client to proceed, proactively, with permanent solution to manage the PFAS contamination on site and minimize long-term operational costs.