Workers Tuesday were to complete cleaning up 55 to 60 gallons of gear oil that spilled Saturday from a wind turbine generator high on a ridgeline in Sheffield.
The turbine is one of 16 recently installed by First Wind, a Boston company, which is constructing northern Vermont's first commercial wind farm. The turbines are being tested and have not begun generating power.
"Most of the oil spilled on the turbine itself and the gravel pad around it, but a small amount traveled 200 yards away," Chuck Schwer, head of the state's spill management program, said Tuesday.
He said none of the oil reached a water source.
John Lamontagne, a spokesman for First Wind, said no natural resource was affected by the leak.
"In areas where oil reached the soil, the soil has been removed and is being cleaned," he said and new grass planted.
The turbine generators sit atop 262-foot-tall towers. Each holds about 110 gallons of hydraulic and lubricating oils, according to a draft spill prevention plan the company filed in 2006, when it was seeking a permit from the Public Service Board.
Opponents of commercial wind projects on Vermont's ridgelines have warned in the past that wind development raises new pollution dangers on fragile mountaintops.
The leak was caused by a "mechanical issue involving an oil line in the generator," Lamontagne said.
He said the company was inspecting the remaining 15 turbines to be certain there are no other leaks. The Sheffield project is expected to begin generating power within the next six weeks.