An environmental advocacy group says it has found concerning levels of "forever chemicals" in the Winooski River just downstream from the polluted Vermont Air National Guard base in South Burlington.
A group called Vermont PFAS/Military Poisons Coalition says water samples it took at the Salmon Hole, just below the Winooski Falls dam, showed elevated levels of per- and polyfluoroalkyl substances.
That’s the same class of chemicals that contaminated hundreds of wells in the Bennington area, leached into the groundwater at the Air Guard base, and regularly seep out of operating and closed landfills in Vermont.
The group says its test samples contained 40.5 parts per trillion (ppt) for the five PFAS compounds regulated by Vermont for drinking water, which must be below 20 ppt for those five compounds.
Vermont has no specific threshold for surface waters such as those the group tested, but the state is conducting its own tests of surface waters and fish for the presence of PFAS.
There are thousands of PFAS compounds that have been produced for decades, used for everything from stain-proofing rugs to water-proofing clothing and making cookware nonstick. They're called "forever chemicals" because carbon fluorine bonds upon which they are based are super-strong and don't break down naturally in the environment.
PFAS has been linked to a number of health problems, including cancer,
a suppressed immune system, reduced fertility and high cholesterol, according to the Environmental Protection Agency.
The group’s tests also showed the presence of five other PFAS chemicals that Vermont does not regulate. When those chemicals are included, the total rose to 145 ppt, according to the group.
The group did its own samples because the state Department of Environmental Conservation testing has been insufficient and non-transparent, said member James Ehlers, a long-time water quality advocate. Because the chemicals don't break down naturally in the environment, they can accumulate in the bodies of organisms, especially fish, so even seemingly low concentrations can be problematic, Ehlers said.
“Why aren’t they being proactive about this?” Ehlers said of the state. “Why are they waiting for a bunch of volunteers to do their jobs for them?”
Peter Walke, the DEC commissioner, rebutted Ehlers' statement. This year, Walke said, the agency launched a multiyear program to sample surface water and fish tissue in multiple locations in the state. After collecting the data, the Department of Health will consider whether health warnings about consuming fish are necessary, Walke said. Results from testing in October are already in.
He noted that the method used by the group's commercial lab, which is not certified, is different than that used by the state — an EPA-approved testing method that involves "isotope dilution."
The group used a testing kit from a company in Skokie, Ill., called Cyclopure. A volunteer collected the samples in October using the proscribed protocol and sent them off to the lab, which reported the results, Ehlers said.
Tests for PFAS are very sensitive to contamination. Because the chemicals are ubiquitous in the environment and common in products such as food containers and clothing, care must be taken to ensure samples are collected properly. Those protocols were all followed, Ehlers said.
The availability of such tests to the public has created challenges for regulators and water supply managers, whose own testing protocols and results can differ from those performed by volunteers. Home tests can muddy the waters when it comes to public confidence.
Earlier this year, a volunteer working with Consumer Reports collected a sample of drinking water from a tap in Shelburne that returned a PFAS result of 5.8 ppt. That’s below the 20 ppt threshold set by Vermont, and well below the 70 ppt federal standard.
The result was higher, however, than what the Champlain Water District’s own test had found. The district could find no detectable level of PFAS in the water supply.
Walke said the DEC has reached out to Cyclopure to better understand the technology it uses in its kits. The state has not heard back from the company.
The location of the tests strongly suggest that the Air Guard base is at least partly responsible for the contamination, but there are likely other sources, Ehlers said. He noted that there's also landfill leachate that's trucked to the Montpelier treatment plant and discharged into the Winooski River, without removing the PFAS.
The state’s sampling program at three locations in the Winooski River has detected PFAS. In October, two surface water tests from locations near the Air Guard base showed levels of 10 ppt and 7 ppt for two of the five regulated PFAS compounds.
A third sample, taken from where the Winooski enters Lake Champlain, held none of the regulated compounds, according to the state.
Also in October, the state tested nine samples of three species of fish taken from the Winooski — yellow perch, brown bullhead and Northern pike. Tissue samples turned up one of the five chemicals, PFOS, at between 1.6 parts per billion and 15 ppb, for a mean level of 6.5 ppb. That figure is within the range of "typical background concentrations" for PFOS in fish tissue, according to DEC staff. Additional water and tissue sampling is planned through 2022, including above and below the Air Guard base, Walke said.
Rick Levey and Kelsey Colbert gathering water samples in Lake Memphremagog
Officials with the DEC have said that a plume of PFAS groundwater contamination from the Air Guard base is making its way to the Winooski River. The base for decades used firefighting foam made with PFAS meant to more quickly extinguish fuel fires. Soldiers regularly set things on fire and practiced dousing the flames with the foam. The base now uses a foam considered less toxic, but which still contains PFAS.
The chemicals have seeped into the groundwater and, despite clean-up efforts, have migrated off the property, according to the DEC.
A neighboring dairy farmer, John Belter, is suing the City of Burlington, which owns the airport property and leases it to the Guard, over the contamination. Belter claims PFAS levels in an agricultural well on his land are 13 times the state drinking water standard, while a creek running across his land has levels 31 times that high.
Ehlers said the state’s drinking water standard was implemented hastily in 2016 after the Bennington contamination was discovered. Five years later, the world has learned a great deal more about the dangers of PFAS, and the standard desperately needs updating.
“They’re sliding by on the fact that, because these other compounds aren’t regulated, they pretend they don’t exist,” Ehlers said.