Breaking the cycle of PFAS on Nantucket

The island community teamed with CDM Smith experts to evaluate potential sources of PFAS contamination. Nantucket is moving toward better informed PFAS reduction and control strategies in the sewer collection system, wastewater treatment plant and landfill operations, while providing public water to impacted residents when possible.

The invisible threat surfaces

The regulations landed in October 2020. Massachusetts set enforceable drinking water standards for six PFAS compounds: PFOS, PFOA, PFHxS, PFNA, PFHpA and PFDA: so-called “forever chemicals” that don’t break down in the environment. On Nantucket, officials knew what those standards meant. The airport had been required to use PFAS-laden firefighting foam for decades, and preliminary tests had been showing concerning signs for months.

The contamination wasn’t coming from just one place. Airport firefighting foam was a known culprit, but PFAS compounds were also appearing in wastewater treatment residuals, landfill leachate and domestic wells. Even the island’s composting program had unknowingly become a PFAS transmitter. “For decades, manufacturers produced everyday products with PFAS, while communities like this island were exposed without knowing it,” explains PFAS communications specialist Rose Hanson.

A career-defining challenge

Nantucket is famous for its postcard-perfect beaches and charming cobblestone streets -- the quintessential New England escape. When environmental engineer Sarah Jakositz visits, her destination is a little different: the island’s wastewater treatment plant. Three years into her job, she’d learned that environmental engineering challenges took on a whole new meaning on an island. Nantucket’s entire water supply hinged on the island’s single aquifer.

"Nantucket was the first project that sparked something in me I hadn’t felt before. Islands can’t just pull resources from neighboring towns. That creates a strong sense of ownership and problem-solving," Sarah says.

Breaking the cycle

Helping the public understand the challenge was the linchpin. CDM Smith built a PFAS cycle graphic with the town to show residents exactly how these chemicals moved through their community.

“With PFAS especially, transparency is our top priority. It’s an evolving science and can be scary,” Sarah notes. The public resource demonstrated how PFAS transports from firefighting foam to groundwater, from wastewater to biosolids, from compost back to soil and to the aquifer. If residents could see how PFAS moved through systems, they could also see where interventions might work: the airport could switch to PFAS-free firefighting foam, the wastewater treatment facility could implement PFAS management technologies, and landfill leachate treatment could help reduce PFAS concentrations entering the wastewater system.

That commitment to transparency became crucial in September 2023 as tests showed that private wells on a mid-island road had PFAS levels above what the state considers safe, and the town moved fast. Nantucket officials connected those homes to treated municipal water within months.

By early 2025, the situation expanded. One of the seven public wells supplying Nantucket’s water system showed rising PFAS levels and had to be shut down, and the town moved quickly to address the well. The early commitment to transparency meant residents understood the issue and knew about the Town’s efforts to address it.

“It’s not easy to share that a contaminant like PFAS has been detected,” Rose explains. “These are tough conversations, but they’re necessary. Our bigger goal is to help the town break this cycle. We didn’t just charge in with ’we’re going to fix this big scary thing.’ We took the time to get everyone talking first.”

Planning smart, not just fast

“CDM Smith took a step back and outlined the whole roadmap process, so the town could make smart decisions. Not just for today, but for years to come,” Sarah explains. Creating a roadmap for the Town meant designing clear decision paths and action plans with built-in checkpoints, so Nantucket officials could make their own informed choices as the science of PFAS evolves.

“The biggest challenge is that PFAS science keeps changing, and the media often makes it scarier than it needs to be,” Sarah says. “People hear buzzwords and they panic. That’s why we slow down and plan carefully around what each community actually needs.”

Beyond Nantucket's shores

A 2024 US Geological Survey study found that between 71 and 95 million people may be drinking groundwater with detectable PFAS in the US. The integrated approach of combining wastewater investigation, landfill source analysis, technical planning and community communication is an approach that is already informing how other communities tackle similar PFAS challenges.

In 2025, Nantucket took the notable step of hiring a full-time municipal employee dedicated solely to PFAS: mitigation, testing, research, communication and education, which reflects the seriousness the town has embraced in its long-term management strategy.

“Nantucket has always been a place where people work together to protect what matters,” Rose recounts. “By reducing PFAS use, advocating for regulations that treat PFAS as a family of chemicals, and supporting PFAS-free alternatives, the island community is showing how collective action at the local level can drive meaningful change.”

The PFAS cycle framework built for Nantucket is now being adapted for other communities. The communication strategies are being refined and shared. The technical work is informing treatment designs in other regions, too.

Breaking the cycle of PFAS on Nantucket

Breaking the cycle of PFAS on Nantucket

Client

Location

Practices

Markets

Priorities

Connect with an expert

The invisible threat surfaces

Mapping of PFAS migration pathways across the island

Transparency as a tool

A roadmap built on wastewater

From findings to action

Client

Location

Practices

Markets

Priorities

Connect with an expert

A career-defining challenge

Nantucket was the first project that sparked something in me I hadn’t felt before. Islands can’t just pull resources from neighboring towns. That creates a strong sense of ownership and problem-solving.

No playbook, no problem