Breaking the cycle of PFAS on Nantucket 

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.

No playbook, no problem

CDM Smith assembled a Nantucket task force spanning disciplines: water treatment engineers, PFAS chemists, wastewater specialists, landfill investigators and risk communication experts. Their first major task was comprehensive: map every potential PFAS pathway across the island.

Much of this work centered on the wastewater system, from treatment plant operations and biosolids to landfill leachate flows. This meant coordinating with virtually every town department and interviewing staff, reviewing decades of records, and sampling groundwater, surface water and wastewater, as well as reviewing soil sample data collected by others. 

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. 

Paying it forward

For Sarah, the project changed how she works. “Nantucket taught me that utilities facing contamination need someone who will slow down, listen, and build a treatment roadmap together.

“This work has directly shaped my approach in Fort Wayne, Indiana, where we’re helping the city investigate PFAS and other emerging contaminants. We use a decision roadmap to guide the project from start to finish, something we first developed in Nantucket. It taught me that client-focused planning, taking a step back, understanding needs, and empowering clients is critical,” she says.

On Nantucket, the work continues. CDM Smith is still sampling, piloting treatment approaches and laying the groundwork for future PFAS destruction technologies, all aimed at finding the sources to the wastewater treatment facility and implementing meaningful reduction and control.

As Rose puts it, “The key is slowing down to understand client needs and empowering them to make the right decisions for their community. Utilities facing contamination don’t just need technical expertise. They need someone who will really listen and figure out the path forward together."