The Friends of the Winooski River: Blog

One of the questions people most often ask Friends of the Winooski is “What are you doing about PFAS?” Jenny Blair, MD, of Montpelier, volunteered to help us provide some answers, and her findings are presented below.

Vermonters’ concern about this family of “forever chemicals” has grown in recent years, especially after the chemicals were found contaminating wells in the Bennington area in 2016.

Vermont state agencies are still working to build an understanding of where PFAS is and where it’s coming from.

We are concerned about PFAS too, and we applaud federal and state efforts to address the problem. Unfortunately, because of the very nature of PFAS, studying and mitigating it requires more resources than we have. Our participation in the state’s volunteer water-quality monitoring program allows us to analyze water samples for nitrate, phosphate, and chloride. In a different world, we could use our network of volunteers to collect PFAS samples. But in the here and now, the fact is that the analysis of water samples for PFAS is extremely costly. This may change in the future, but for now, we have to focus on well-understood challenges to our watershed, and fundable solutions, such as reducing sediment and nutrient pollution.

In the meantime, here’s a primer on PFAS, how Vermont is dealing with it, and what everyone can do to avoid it and reduce its release into the environment.

What is PFAS, exactly, and why is it a problem?

We hear people refer to PFAS as if it were a single substance, but in fact the acronym is a catch-all for a family of thousands of manufactured chemicals called per- and polyfluoroalkyl substances that feature  a carbon atom bonded to a fluorine atom. They’ve been used since the 1940s in products like paint, nonstick cookware, carpets, cleaning products, and many others. These chemicals build up in the environment and in the bodies of animals, including humans. Some are predicted to take thousands of years to break down.

There’s strong evidence linking PFAS chemicals to weakened antibody response, abnormal cholesterol, reduced birth weight, and kidney cancer. Some evidence ties the chemicals to other cancers, abnormal liver function, thyroid problems, ulcerative colitis, and pregnancy-induced hypertension. Certain people are at higher risk: workers who make PFAS, firefighters who use fire-suppressing foam spray, and children who ingest objects, for example.

Unfortunately, teasing out exactly which specific PFAS chemical at what level of exposure may cause which health effects is a fiendishly difficult task. Not only are there thousands of different PFAS, but manufacturers frequently change how they use the chemicals. That means it’s hard to even measure how much exposure a person may be getting. In addition, unlike some faster-acting toxins, any damage they cause can be subtle and accrue over time, further complicating research efforts. 

What is Vermont doing about PFAS?

Vermont’ work on addressing PFAS contamination is considered progressive. The Agency of Natural Resources’ Department of Environmental Conservation (DEC) is working on the issue in partnership with other state and federal agencies. The DEC’s roadmap details PFAS-related milestones so far, including establishing standards for drinking water and surface water; checking soils around the state for PFAS; collecting thousands of gallons of PFAS-containing foam from fire departments statewide; investigating where PFAS in the state comes from, including industry and landfills; and a number of other steps. You can read about the state’s sampling program here. Vermont is also supporting communities that are under “do not drink” orders due to PFAS-contaminated water systems, including Craftsbury Common, which receives bottled drinking water weekly.

How can I find PFAS trouble spots?

Check out the Environmental Working Group’s (EWG’s) interactive map of suspected PFAS industrial discharges. A Vermont-specific map can be found at the Natural Resources Atlas. Locations in central Vermont that are thought to be releasing PFAS into the environment include automotive and oil businesses as well as the Barre, Northfield, Stowe, and Montpelier wastewater treatment facilities.

Is the federal government paying attention to PFAS?

Yes. Federal agencies, including the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC), are taking an active interest in studying PFAS. The EPA has developed a “roadmap” and the White House has put people on the problem as well. Researchers are developing techniques to measure PFAS in the environment, as well as ways to remove PFAS from drinking water and dispose of them safely. And the National Academies of Science, Engineering and Medicine offer some basic medical advice for people who are found to have elevated levels of PFAS in blood tests (that’s for those few people who actually get tested—these tests are expensive).

Does Vermont have standards for PFAS in drinking water?

Yes. In 2019, the governor signed Act 21, a law regulating PFAS in both surface and drinking waters. The law led to regulations in 2020 stipulating that in drinking water, the concentrations of five common chemicals added together cannot exceed 20 parts per trillion (or 20 nanograms/liter). These five are PFOA (perfluorooctanoic acid), PFOS (perfluorooctane sulfonic acid), PFHxS (perfluorohexane sulfonic acid), PFHpA (perfluoroheptanoic acid), and PFNA (perfluorononanoic acid). The law also requires water systems to monitor for PFAS routinely alongside its checks for other contaminants. Some argue that these limits are still too permissive.

How do you test water for PFAS?

Using careful technique, you take water samples and bring them to a lab that’s equipped to check for it; a skilled technician takes it from there. In 2018, the United States Environmental Protection Agency published a standard procedure for checking water for 18 of the many thousands of existing PFAS, called Method 537.1. This method is validated, meaning it has been checked out and proven suitable. We won’t bore you with the nitty-gritty, but if you’re at home with chemical analysis you can read all about it here. Other methods are in development and not yet validated, and Vermont is piloting some of them to see how they stack up against Method 537.1. Notably, testing water for PFAS is very expensive and requires specialized equipment.

How do people get exposed?

By a variety of routes—drinking water, food, fast-food packaging, microwave popcorn bags, certain types of fertilizer, industrial products like fire-extinguishing foam, and a vast array of consumer products, including food wrappers, mattresses, furniture, water-repellent carpets, shampoo, dental floss, and makeup, to name just a few. Vermont has found PFAS in car washes and waxes. It also turns up around tanneries. Drinking water is thought to account for about one-fifth of human exposure.

 We may not only ingest PFAS but inhale them via contaminated dust. Small amounts can also be absorbed through the skin.

What about swimming?

Swimming in waters that contain PFAS probably won’t lead to significant exposure unless you ingest a lot of water. When you’re deciding whether a body of water is safe to swim in, contamination with bacteria and blue-green algae is more immediately important. HealthVermont and the Agency of Natural Resources have information on swimming safety. Friends of the Winooski’s work to reduce sediment and phosphorus pollution is intended to reduce the occurrence of these algal blooms in our watershed and Lake Champlain.