The source of an underground gasoline leak in downtown Moab has been closed, cleanup is under way and families are returning to homes evacuated because of the health threat, according to a state official.

Brent Bradford, director of the Utah Bureau of Solid and Hazardous Waste, said Friday a system of wells drilled last spring to pump gasoline off the aquifer is working as planned and cleanup should be complete within two instead of three years.Three of the four families evacuated last winter chose to return over the past few weeks to homes newly-equipped with ventilation systems.

Meanwhile, the state's attempt to recover costs of the various projects continues, and no conclusions have been reached on whether birds and fish in a swamp the gasoline may have seeped into were affected, Bradford said.

The gasoline plume, estimated at approximately 50,000 gallons, was first identified two years ago, flowing in a northwesterly direction on the water table in the vicinity of Second South and Main Street.

Federal surveyors figured it covered a six-acre area. By the time cleanup began, the pool spread over approximately 12 acres and was an average of 18 inches deep, Bradford said.

The state pressed the federal Environmental Protection Agency for emergency removal action, based on air samplings of noxious vapors at a commercial building directly over the plume and in private residences where benzene levels far exceeded safe limits.

Finally the EPA sent $80,000, for the first time tapping into part of the "Superfund" program.

The state spent $69,000 from the fund to build the pump and treatment system in Moab and later allocated approximately $40,000 more from the EPA for work on the private homes and the relocation program.