ST. CLOUD — Contaminated fuel at two gas stations in the St. Cloud area in August caused thousands of dollars in damage to vehicles, with police investigating the contamination as possible vandalism.

It’s believed to have happened Aug. 16 at First Fuel Bank’s locations in St. Cloud and nearby Waite Park.

First Fuel CEO Jim Feneis said that the station notified customers of a possible problem as soon as it was detected. He believes 59 customers used the contaminated fuel.

“We were proactive once we realized we had a problem,” Feneis said. He said the company warned customers of potential damage and fixed damaged vehicles.

Affected vehicles included some new city of St. Cloud recycling trucks that were making rounds for the first time. Because the trucks were new, it took city staff a while to figure out the fuel was the source of the problem since they weren’t familiar with the trucks. Three garbage trucks, a street sweeper and two fire trucks also had problems.

Gerald Kaeter, an official in the public works department, said they city would have to buy three new fuel filters at a cost of about $15,000. He expected insurance to cover the expense.

Feneis said he had to dispose of 55,000 gallons of diesel fuel valued at more than $200,000.

Feneis said it’s not hard for someone to get access to underground tanks. He said few stations lock their tanks because the locks are prone to corrode and hard to unlock.