Bennington, Vt. — State officials have discovered a well in Bennington contaminated with perfluorooctanoic acid. That brings the number of towns the state has tested for the industrial toxin to three.

Chemfab, the company suspected to have contaminated North Bennington private wells, was originally based in Bennington, Department of Environmental Conservation Commissioner Alyssa Schuren said.

The tainted well is located at a residence on Northside Drive.

In North Bennington, more than 100 wells have tested positive for higher than recommended levels of the industrial toxin. The state has also begun testing at Warren Wire in Pownal, where the same class of chemicals is suspected to have been used.

Many residences in the area are connected to a North Bennington municipal water supply, which has been tested three times and has shown no signs of contamination, Schuren said. The state is testing residential wells in the vicinity.

Of 185 wells tested in North Bennington, 104 showed water with concentrations of PFOA greater than the state’s recommended 20 parts per trillion, Schuren said. Another 11 of those wells had detectable levels of the chemical below 20 parts per trillion. The remaining 63 did not present detectable levels of the toxin.

Most of the wells with the highest concentrations of the contaminant are nearest the Chemfab facility, according to maps provided by the DEC. The state has not yet established by what route the chemical made its way from the plant into subsurface water, Schuren said.

The Vermont Department of Environmental Conservation has also initiated testing for the same class of chemicals around the former Warren Wire factory in Pownal, which, like Chemfab, manufactured products containing the polymer trademarked as Teflon. PFOA was used in the manufacture of non-stick coatings but was to be phased out nationwide by 2015 under an agreement with the EPA.

The Pownal tests focus on a water supply that serves 450 residents and is about 1,000 feet from the factory.

DEC officials say the tests are being undertaken purely as a precaution and results are expected in days.

The state has said it will be another few weeks before the Department of Health is able to begin blood tests on affected residents.

The Department of Health is working with the Centers for Disease Control and Prevention, and the federal agency has to sign off on the state’s testing program.

Deb Markowitz, secretary of the Agency of Natural Resources, said her agency is attempting by next week to prepare a legislative response to the PFOA contamination problem.

Staffers at the Agency of Natural Resources are currently determining whether similar contamination may have occurred elsewhere in the state, Markowitz said.

“Once we have any evidence they might have been used elsewhere, we will test,” Markowitz said.

Markowitz said the state is currently in negotiations with Saint-Gobain to recoup costs for agency time and resources spent on identifying the scope of the contamination problem.

The company, she said, will be required to remediate the contaminated wells.

State officials have interviewed five former Chemlab workers as part of an investigation of the Bennington contamination.

Markowitz and Schuren released Wednesday afternoon correspondence between the state and Chemfab. The documents are available on the DEC’s website.

Entrepreneur John Ransom Cook founded both Chemfab and Warren Wire more than four decades ago.

At other PFOA-contaminated sites in the United States, the chemical was introduced into the environment through factories’ smokestacks, according to DuPont documents released in the course of a successful lawsuit against that company over pollution in West Virginia.

Saint-Gobain Performance Plastics purchased Chemfab in 2000 and closed the plant in North Bennington two years later. Schuren said the company moved its operations to New Hampshire at least in part to escape Vermont’s air pollution standards. The Union Leader has reported that PFOA has been found in tap water at the company’s plant in Merrimack, N.H.

PFOA is believed to cause cancer and disrupt endocrine systems, affecting the liver, kidneys, testes and bladder. It is also thought to cause hypertension and high cholesterol.

Blood testing is available for residents whose water was contaminated, said state toxicologist Sarah Vose. The state has asked Saint-Gobain to pay for the testing, but the company has not yet responded. The federal Centers for Disease Control has said it would pay for the tests, Schuren said.

However, the results aren’t likely to predict health effects, Vose said. It takes two to four years to eliminate half the PFOA in the human body at any time, Vose said, and the chemical doesn’t metabolize in humans.

The state set an advisory limit for PFOA in drinking water — 20 parts per trillion — in response to the Chemfab contamination, Schuren said. No federal regulatory limits exist for the chemical, although the EPA advises against exposure to water containing PFOA in concentrations greater than 400 parts per trillion.

About 100,000 other chemicals whose health effects are unknown also lack established federal regulatory limits, Schuren said.