As per federal and state rules, USTs owners and operators are required to test tanks for leaks on a monthly basis in order to protect groundwater from pollution.

EPA inspected the AMA Mini Marts in October 2009 and found that all of the USTs at the three sites lacked the required monthly release detection for the tanks and annual testing required for the associated piping, a violation of the Resource Conservation and Recovery Act.

The Office of Compliance and Enforcement in Seattle of EPA director Edward Kowalski said leaking tanks can also endanger drinking water.

"Groundwater is often a community’s only source of drinking water, owners of tanks must do their part to prevent oil and gas leaks and help protect people from polluted water," Kowalski said.