[T]he EPA has set a recommended limit for the presence in drinking water of the chemical PFOA, which has been found in the water sources for hundreds of Vermont homes, but the figure allows for more exposure than a Vermont rule does.
The Environmental Protection Agency last week announced an advisory limit of 70 parts per trillion in drinking water for perfluorooctanoic acid, or PFOA. The number is a guideline for operators of water systems, not a regulation. The EPA said it provides “a margin of protection from a lifetime of exposure.”
Vermont put in place a rule this year setting a limit of 20 parts per trillion. State toxicologist Dr. Sarah Vose has said Vermont’s Health Department arrived at the lower number out of concern for infants and their increased sensitivity to PFOA. The EPA several years ago set a preliminary advisory limit of 400 parts per trillion.
The EPA advisory is important because it documents harms to human health associated with exposure to PFOA, said the Vermont Natural Resources Council’s policy and water program director, Jon Groveman.
“It’s a good first step, and I’m glad they’ve done it, but I wish they’d set a daily water standard,” Groveman said.
The company whose North Bennington property is believed to have tainted wells with PFOA, Saint-Gobain Performance Plastics, has argued that no science supports the state’s exposure limit. The firm could be held financially liable for remediation if it is proved to be the source of the contamination.
Vose has said Vermont relied in part on a nearly 300-page study by the EPA on PFOA’s health effects, a draft of which the agency released in 2014.
The EPA said research indicates that exposure to PFOA over certain levels may result in low birth weight or birth defects; testicular and kidney cancer; liver damage; effects on the immune system and thyroid; and other harm.
PFOA was used in the manufacture of Teflon products until the industry voluntarily phased it out by 2015.
A lawsuit against chemicals giant DuPont in the 1990s revealed that the company knew decades earlier of human health risks associated with PFOA. The settlement funded an unprecedented study of PFOA’s long-term effects on workers and residents near one of the company’s West Virginia factories.
The study found a close relationship between PFOA and several types of cancers, as well as attention deficit disorder, hypertension and high cholesterol.
More than 150 North Bennington and Bennington wells have been found to contain perfluorooctanoic acid at levels over 20 parts per trillion.
The chemical is thought to have originated from the former Chemfab factories in Bennington and North Bennington, which both manufactured Teflon-coated fiberglass. The Warren Wire factory in Pownal, which was started by the same entrepreneur, is another suspected source.
At least two ponds in the North Bennington area, along with the Walloomsac River, also contain PFOA in sediment, according to test results released last month, but state officials say it’s not a risk to human health.
The state recently tested 63 private wells in Pownal after a municipal water supply serving around 450 people was found to carry PFOA in concentrations above the state’s recommended limit. Four of those 63 came back with concentrations above 20 parts per trillion. The highest concentration was 66 parts per trillion.
Officials have not determined by what route the chemical may have left the factories and found its way into the water. But at other PFOA-contaminated sites in the United States, the chemical was introduced into the environment through smokestacks, according to documents released in the lawsuit against DuPont over PFOA pollution in West Virginia.
Blood testing is available for Vermont residents whose water was contaminated, as is clean drinking water.
