When per- and poly-fluoroalkyl substances (PFAS) were detected above the regulatory limit in two drinking water wells in the Town of Millis, Massachusetts, the wells were immediately taken offline. Having worked with the Town for 15 years, Kleinfelder was quickly engaged to provide engineering services in design, permitting, and construction phase services for a new PFAS treatment facility.

Drinking Water Supply and Demand

The D’Angelis Water Treatment Facility treats Well 1 and Well 2, and supplies almost 50% of the Town’s typical drinking water demand. It was removed from service in September 2020 when voluntary testing by the Town revealed PFAS levels elevated above new State drinking water PFAS regulations. With the D’Angelis Facility offline, Millis was faced with having to overpump its other wells to meet demand. To restore the wells to service, a new PFAS removal facility needed to be designed and constructed at the existing site, which presented unique site constraints and geotechnical challenges. Decisive and proactive action on the part of the Town, in conjunction with Kleinfelder, was critical to secure funding, comply with new regulations, and protect public health.

New PFAS Treatment Facility

Kleinfelder and the Town worked quickly and collaboratively to institute a public outreach program and secure grant funding for preliminary design of a PFAS treatment facility, while also navigating new regulations and stakeholder notification requirements. The new facility includes four 20,000-pound filtration vessels containing granular activated carbon (GAC) for PFAS removal, a 3,000-square-foot treatment building, residuals management tanks, and new mechanical, electrical, and plumbing systems. Kleinfelder provided process, structural, geotechnical, architectural, civil, environmental/permitting, bidding, and construction administration services. Kleinfelder’s design included improvements to well capacity, removal of an unsafe storage building, and specialized ground improvements (rammed aggregate piers) to make beneficial use of the limited site footprint with poor soils. Kleinfelder’s designs anticipated future changes in the dynamic water regulatory environment. The facility design includes flexibility features to accommodate future treatment infrastructure if needed.

Kleinfelder was subsequently awarded the PFAS design of the Town’s Well 3.

Project Results

The project was completed on-schedule and within the proposed budget, restoring the Town’s most important water source. The Town is able to provide 1.22 million gallons of clean drinking water to Millis residents each day. The design of the plant allows Millis to comply with current and future PFAS regulations by utilizing a lead-lag filtration design and removing PFAS to below laboratory detection limits.

Project Details

Location:
Millis, MA
Owner:
Town of Millis