What to know about water contamination testing near Burlington airport

The Vermont Air National Guard is aiming to figure out how far contamination by toxic chemicals has spread by testing groundwater and soil in neighboring communities.

PFAS, a family of chemicals linked to several adverse health effects, were found in 2016 at six sites at the Guard base at the Burlington International Airport in South Burlington.

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The contractors have begun digging monitoring wells in areas within roughly a one-mile radius of the base, said Lt. Chelsea Clark, a spokesperson for the Air National Guard. The testing may be expanded as the early sample results come back.

The family of chemicals have historically been used to make Teflon, wire coatings and car wax. They are also components of a firefighting foam used by the Air Force to fight petroleum fires for nearly 50 years.

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The most common variants are perfluorooctanoic acid, known as PFOA, and Perfluorooctanesulfonic acid,or PFOS. Both were found at the base.

The family of compounds made headlines in Vermont in 2016, when more than 100 private wells in the Bennington area were found to contain PFOA in levels exceeding Vermont's safety standards.

Exposure to the chemicals has been linked to cancer, increased cholesterol and lowered ability to get pregnant, according to the Centers for Disease Control. They may also affect the development of children.

Most Americans have a small but measurable amount of PFAS in their blood, according to the CDC, and scientists have yet to establish a "safe" blood level for the chemicals.

People get exposed by drinking contaminated water or eating contaminated foods.

According to the federal Environmental Protection Agency, water containing more than 70 parts per trillion of the chemicals is considered unsafe. Vermont uses a more conservative standard of 20 parts per trillion.

Is Chittenden County drinking water contaminated?

If you live in Burlington, South Burlington, Winooski, Colchester or any of the 12 Chittenden County municipalities served by the Champlain Water District and you're connected to the municipal water supply, your water is PFAS-free.

The drinking water supplied throughout Chittenden County is sourced from deep in Shelburne Bay and is not considered to be a contamination risk.

The utility has tested the drinking water three times a year for the past five years. None of the PFAS chemicals were found.

A private agricultural well on a dairy farm north of the airport and a supply well on the base have tested positive. A filtration system was installed on the agricultural well.

The Agency of Natural Resources presented a plan for statewide testing last month. State officials plan to increase their monitoring of Vermont's hundreds of public water systems. They also plan test high-risk areas, such as the areas surrounding car washes.

Contact Jess Aloe at 802-660-1874 or [email protected]. Follow her on Twitter @jess_aloe