Great Falls — The Great Falls Citizens Association hosted Matt Pawa, an attorney with experience dealing with groundwater contamination Thursday, June 20. Pawa has worked on behalf of the New Hampshire Attorney General’s office for the past 10 years trying to hold oil companies liable for gasoline byproducts in groundwater.

The former Exxon station at the corner of Georgetown Pike and Walker Road, which ceased to be an operating gas station late last year, was found to have gasoline remnants onsite. A TD Bank branch has been proposed for the location.

Pawa’s primary concern is methyl tertiary butyl ether, or MTBE, an additive that was put into gasoline until 2006. It made up about 15 percent of the fuel that was put into automobiles. The EPA has tentatively classified MTBE as a “possible human carcinogen.”

In New Hampshire, MTBE was found in a number of private and public wells and most petroleum companies settled for $136.5 million. ExxonMobil did not settle, and the trial resulted in a $236 million judgment against them in April of this year.

The problem, Pawa said, is that MTBE travels farther and faster than other gasoline constituents, “essentially at the speed of groundwater,” he said, and it resists biodegradation.

“The fact that there has been no contamination found outside the site is very good news,” Pawa said. “But scientifically speaking, that doesn’t mean that Great Falls is out of the woods.”

According to a report by the Virginia Department of Environmental Quality, there have been high levels reported in monitoring wells on the site of the Exxon station.

The June 1, 2012 data shows levels ranging from 140,000 parts per billion to as low as .8. The potable well onsite, which was previously used by the station for the restroom and other uses, has three depths, and has registered numbers of 1,400, 1,600 and 860 parts per billion, with the latter number coming from a depth of 65 feet.

“Most people can taste MTBE in their water at around 20, 30, 40 parts per billion, it has sort of a turpentine taste and smell,” he said. “Private wells are more susceptible for MTBE, because they are shallower, usually around 15-20 feet, and because they are not monitored by the government, just voluntarily by the owners.” There is no maximum limit of MTBE in Virginia, but Pawa said New Hampshire’s threshold is 13 parts per billion.

GFCA board member Amy Stephan said that Pawa’s appearance in Great Falls is not a precursor for any kind of legal action.

“He’s not here to encourage legal action, but to share his knowledge and experience with us,” she said. Jackie Taylor, GFCA president, says that the presentation will not directly lead to action as of yet. “We coordinated Mr. Pawa’s appearance here, and we are grateful to him for sharing his time and expertise with us,” she said. “But we have not endorsed or approved any action in regards to this topic, and nothing will be done without an official GFCA board action. This is just a part of us doing our due diligence.”