A tank at an East Haven terminal has been flagged by the state Department of Consumer Protection as the source of bad gas reported at seven gas stations over the past two weeks, including at one 7-Eleven station in Montville.

Consumer Protection Commissioner William Rubenstein said in a phone interview Thursday that the contaminated gas has been reported by eight or nine consumers who made complaints to his department. Honda and Toyota dealerships have also reported about 16 jobs each that apparently involved the bad gas, he said, but could not say what towns the dealers are in.

Rubenstein's staff traced the bad gas, which may be contaminated with seawater, to one tank that has now been shut down and "red-tagged" so that no gas can flow out of it, he said. While the problem may be more widespread, Rubenstein said he thinks it's been contained.

"We think the problem is isolated to the source we found," Rubenstein said. "And we think the contamination is not going into the system now and whatever was in the system has worked its way through."

The affected gas stations involve five Mobil stations and one Stop & Shop station in the New Haven-Milford area and a Montville 7-Eleven on Route 32 (Norwich-New London Turnpike).

The Dallas-based 7-Eleven spokesperson, Carol Davidson, said the company had received some complaints and is working with customers. Gasoline tested at the Montville station Wednesday by Consumer Protection was not contaminated, she said. She urged customers with concerns to call the company at (800) 255-0711.

Kristen A. Hellmer, a spokeswoman for Mobil and Exxon said the company is aware of the problem.

"We apologize to any Exxon or Mobil customers who may be experiencing problems they believe to be related to fuel quality," she said in an email. "Anyone who has concerns about product purchased at an Exxon or Mobil station should Customer Care at 800.243.9966."

Stop & Shop spokesperson Suzi Robinson said her company has no reports of any issues at the station located at 1360 East Town Road in Milford and has not been notified of any state investigation.

"We continually test our fuel and monitor our filters closely so if there was any issue with the fuel we would know immediately and rectify it," she said in an email.

Rubenstein is urging consumers who may be affected by bad gas to file a complaint with his department, return to the retailer to obtain information about how to be compensated for the problem, and retain all receipts for the gas and any diagnostic or repair work done to the affected vehicle.

Consumers should also notify the Consumer Protection fuel standards unit by calling 860-713-8160 or 1-800-842-2649, or by emailing food.standards@ct.gov. A form for filing a written complaint is available at www.ct.gov/dcp at "Forms." Consumers should also register a complaint, in writing, with the retailer from whom they purchased gasoline.

The investigation is ongoing, Rubenstein said.

p.daddona@theday.com

Stations effected by bad gas

Montville 7-Eleven

Guilford Mobil

Milford Stop & Shop

Fairfield Mobil

Milford Mobil

Long Wharf Mobil

Branford Mobil Rest Area

Source: Connecticut Department of Consumer Protection