Nantucket Charts Course to Break the Cycle of PFAS

On October 2, 2020, the Mass­a­chu­setts Department of Envi­ron­men­tal Protection promulgated drinking water standards for “PFAS-6,” shorthand for six potentially toxic analytes: PFOS, PFOA, PFHxS, PFNA, PFHpA and PFDA. On the island of Nantucket, community leaders wasted no time in responding. And Nantucket’s situation was unique for a community facing PFAS. Named “the Faraway Land” by the Wampanoag tribe, the island’s original inhabitants, Nantucket is a self-sustaining community with many unique envi­ron­men­tal challenges. Residents, visitors and businesses are solely dependent on the infra­struc­ture and resources existing within 48 square miles.

The town’s primary concern is protecting public health and the preser­va­tion of the island’s sole source aquifer, which provides drinking water to everyone on the island. Soon after sampling efforts confirmed their suspicions of PFAS cont­a­m­i­na­tion, the town contracted CDM Smith in July 2020 to develop a unified and proactive PFAS management plan that would help protect the island’s precious groundwater resources.

Certain fire­fight­ing foams had already been identified as potent PFAS spreaders, and the island’s airport—a critical piece of local infra­struc­ture—had been required to use those foams as part of federal regulatory require­ments. The island also has a very active biosolids and composting program, associated with the wastewater treatment facility and landfill, which are receivers of residential and commercial PFAS sources on the island.

To design a treatment and mitigation strategy, CDM Smith helped the town first understand where its PFAS was coming from and how it moved through the local ecosystem.

“This is the first proof of concept of our unique PFAS cycle approach,” said Melissa Harclerode, CDM Smith principal and discipline leader for sustain­abil­ity. “Our bigger goal is to help the town break this cycle and prevent the transport of PFAS from one source to another."

What started as a preliminary inves­ti­ga­tion turned into a multi-year public outreach campaign, an action plan to address the presence of PFAS cont­a­m­i­na­tion from multiple sources—commercial and household use, wastewater treatment residuals, or biosolids, and aqueous film forming foams, or AFFFs—and ongoing strategies to track and understand how to handle the cont­a­m­i­nants as they move through the island’s PFAS cycle.

The project team embarked on a multi-disci­pli­nary effort that included engineers, scientists, planners, and commu­ni­ca­tions specialists who performed outreach to all town departments—water, sewer, airport, public works, solid waste, health, natural resources, fire, public outreach/commu­ni­ca­tions, finance, and the town manager’s office. Other stake­hold­ers included the Nantucket select board, board of health, community groups and residents, as well as state agencies.

CDM Smith PFAS experts developed recom­men­da­tions on how best to break the PFAS cycle through future imple­men­ta­tion of appropriate mitigation and control measures, with the intent of creating a town-wide PFAS source control and reduction plan. Development of a PFAS cycle unique to Nantucket was a critical early step in CDM Smith’s assessment process. Visualizing the island’s unique cycle of cont­a­m­i­na­tion allowed the town to visualize how it could take action and achieve PFAS source reduction and control.

Public education and outreach are critical to the success of a PFAS management plan imple­men­ta­tion. This piece of the project included facil­i­ta­tion of a town-wide PFAS commu­ni­ca­tion team and charter, preparation of a public outreach strategy and plan, development of commu­ni­ca­tion materials (i.e., fact sheets, FAQs, town website updates, press releases), and presen­ta­tions at town community meetings.

CDM Smith developed a wastewater and biosolids decision matrix to guide the town through inves­ti­ga­tion and mitigation of PFAS in the town’s wastewater. The matrix outlines a step-by-step approach to PFAS source iden­ti­fi­ca­tion through a compre­hen­sive data collection and sampling plan.  The matrix also identifies potential mitigation measures to help identify and reduce or eliminate PFAS point sources to the wastewater treatment plants.

The town-wide PFAS assessment project ultimately identified several potential sources of PFAS relative to solid waste operations at the landfill. The Preliminary Assessment of PFAS Town-Wide Planning Approach presented recom­men­da­tions for further evaluation of these potential sources.

CDM Smith continues to support the town of Nantucket with the imple­men­ta­tion of recom­men­da­tions during the follow-on Phase 2A Townwide PFAS assessment effort. This effort has been focused on estab­lish­ing steps for sampling and evaluation to recommend PFAS reduction and mitigation strategies.

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