Challenge


The Barnstable Fire District Water Department (BFDWD) required the reactivation of its Well Pump Station #1 and a new Treatment Building #3. Well #1 is the only well of the 5 Barnstable Fire District wells which was found to not contain PFAS, so it was imperative to reactivate as quickly as possible. Being an aging and lower yield well, with concerns of high iron content, Station #1 was abandoned, and District funds were allotted elsewhere within the system. At one time, Station #1 injected a poly-phosphate product for iron sequestration.

Solution


GZA fast tracked a design and successfully applied for emergency DWSRF funds re-lated to PFAS contamination for the construction of the rehabilitation of Well #1 and construction of the associated treatment building. GZA evaluated raw water quality to determine corrosion control system. GZA determined that a polyphosphate would not be necessary for iron sequestration and that it could exacerbate corrosion control concerns. GZA performed hydraulic analysis of the piping system to determine pump sizing. The design of the rehabilitation included piping, valves, architecture, HVAC, site design, instrumentation, and a backup gas generator. The design of the treat-ment building included a potassium hydroxide system with 2500 gal KOH storage tank. The treatment building was designed as a modular precast concrete building with removable metal panels to replace the storage tank. GZA The treatment build-ing also contains sodium hypochlorite injection and online analyzers for pH and oxi-dation reduction potential to monitor corrosion control system. The construction phase for this project will be completed in Spring 2022. The design phase, bid phase, and emergency SRF applications were fast tracked due to the health concern of PFAS.

Benefit


GZA’s successful execution of the Barnstable Fire District Well 1 and Treatment Build-ing 3 project helps reduce PFAS concentrations by enabling Well 1 to pump PFAS-free treated water to the water system.