This week, the state announced it is suing gasoline refiners over the use of a gasoline additive called MTBE. The chemical was banned in 2005, but the state continues to deal with MTBE contamination.
The chemical was added to gasoline beginning in the 1980s to reduce auto emissions, but it also had some unique properties that made it a particular danger to water supplies.
According to the federal Environmental Protection Agency, MTBE can move through soils much further than other gasoline components. It dissolves in water and it doesn’t degrade quickly.
Chuck Schwer with the site cleanup program of the Department of Environmental Conservation says most MTBE contamination was from leaking underground storage tanks.
“We certainly are still seeing the remnants of historic releases that were fairly large and widespread, primarily due to MTBE,” he says. "We’re still remediating tens of hundreds of those sites. In addition we do still discover MTBE at locations where we hadn’t previously investigated and we’re still seeing occasional drinking water wells with MTBE that’s showing up.”
The state says until 2005 there were roughly 2,000 leaks and spills that involved gasoline containing MTBE.
The largest were in Killington, Hartland and Hinesburg. In Killington more than 40 wells were contaminated.
“The gasoline leaked for quite some time. It was actually discovered by a condominium owner who had basically pure gas at one time coming out of his tap. That particular well still remains quite contaminated,” says Schwer.
Charcoal filtration systems are used to treat water contaminated by MTBE. The state pays to install and maintain the systems for both public and private water sources tainted with the chemical.
The lawsuit is an effort to recover the cost of that treatment.
MTBE gives water an unpleasant taste and smell but the EPA has not determined what constitutes a safe level of the chemical.
The agency says there’s not enough research to set a standard. Studies have shown that inhalation of MTBE by laboratory animals causes cancer.