A state inspector has temporarily closed all 87-octane gas pumps at a Marathon station in Chanhassen after the Department of Commerce got five complaints from motorists who had found water in their fuel.

The regular fuel pumps were shut down Monday morning after the department’s Weights and Measures Division inspected the station at 380 E. Lake Drive, said Ross Corson, a Department of Commerce spokesman.

Although laboratory tests are pending, Corson said a state inspector found reason to believe that the underground 87-octane fuel tank had been contaminated with water. It’s not a common problem, he said, but can happen in the early spring when there is a quick snow melt while the ground is still frozen.

“The water may flow onto the concrete pad and pool,” Corson said. “If there’s any opportunity for it to leak down into a tank, gravity will do its work.”

Kathleen Hollingsworth, of Bloomington, was one of at least five customers to file official complaints about the station Monday.

She and her husband were leaving the Chanhassen Dinner Theatres on Saturday night when they stopped at the Marathon station to fill up. A few minutes after pulling away, their new Chevrolet Impala’s engine shuddered and glided to a stop on Hwy. 5.

“It could have been a dangerous situation,” said Hollingsworth, who is now facing $1,000 in car repairs. “I shudder to think what would happen if this happened to a young driver.”

After towing the vehicle to Suburban Chevrolet, where the Hollingsworths had purchased the car six months ago, mechanics eventually checked the gas tank. “They said it was ‘mostly water, no gas,’ ” she said.

In response to her inquiry with Marathon customer relations, a representative asked that she file a formal complaint.

“All Marathon stations are independently owned and operated and they are responsible for maintaining the quality of the fuel at their station,” according to an e-mail obtained by the Star Tribune.

The owner declined to make any public statement on the matter.

The Department of Commerce received several similar complaints about the station Feb. 1 and 2. That time, an inspector took fuel samples that tested to specifications, Corson said.

Anyone who suspects their vehicle was affected by gas from the station may call the Weights and Measures division at 651-539-1555, or file an online complaint.