Opponents of a soon-to-be-started wind farm in the Aroostook County town of Oakfield took legal action Tuesday in a last-minute attempt to stop the project.

They filed a lawsuit in U.S. District Court in Bangor, aimed at a 50-turbine wind farm to be erected by First Wind of Boston through its subsidiary, Evergreen Wind II LLC. Initial road construction is set to begin before winter on the 150-megawatt project.

A key focus of the complaint, reviewed by the Portland Press Herald, is that the dredging and filling associated with the 59 miles of transmission lines needed to connect the wind farm to the regional power grid would degrade streams that support Atlantic salmon and violate the federal Clean Water Act. The complaint names the U.S. Army Corps of Engineers and the U.S. Department of the Interior as defendants.

A spokesman for First Wind, John Lamontagne, said the company hadn’t yet reviewed the complaint. But he noted that the Army Corps and U.S. Fish and Wildlife Service thoroughly reviewed the $400 million project and its impacts, and concluded that it complied with federal laws.

“We believe this project will be able to deliver significant economic benefits to the region and the town of Oakfield while generating clean renewable energy that will power thousands of homes,” Lamontagne said.

The Oakfield lawsuit mirrors a legal tactic used last year by wind power foes who are trying to block an expansion of the Kibby Mountain wind farm in northwestern Maine. That case is still pending.

Nearly seven years since Maine’s first wind farm went up on Mars Hill, controversy continues over the visual, noise and environmental impacts of power production around the state’s rural lakes and mountains. Opponents have been increasingly frustrated by plans for larger wind farms, a result of changing technology and new, long-term contracts for renewable energy with utilities in southern New England. In Oakfield and at TransCanada’s planned expansion on Sisk Mountain in Franklin County, they see a potential legal path to challenge permits in federal courts.

“Part of this shifts (opposition) from the turbines to the water bodies,” said Lynne Williams, a lawyer representing Oakfield opponents.

The Oakfield complaint says construction will place fill in waterways and wetlands to create turbine pads, roads and other infrastructure. That includes building 59 miles of generator lead lines from the project site to the town of Chester. The route, according to Williams, will cross Molunkus Stream and other tributaries of the East Branch of the Mattawamkeag River, which contains salmon.

The Army Corps violated the federal Clean Water Act by approving a permit for the project, the complaint says. It also asks the court to find that the Army Corps violated federal laws meant to protect bald eagles. At least one eagle nest is located within a mile of the project, Williams said.

Williams was asked whether the lawsuit is meant to derail the Oakfield project, or just force changes that could place turbines farther away from nearby residents. Moving around turbines, she responded, would do little to protect salmon if waterways still are filled or dredged for the transmission lines.

The lawsuit is being filed on behalf of parties that include the Forest Ecology Network, a statewide environmental group, and Protect Our Lakes, a citizen group made up largely of seasonal and year-round residents who live south of Oakfield in Island Falls, on Mattawamkeag and Pleasant lakes.

“It has been frustrating for a lot of us,” said Donna Davidge, an Island Falls summer resident. “We don’t feel there’s been a lot of awareness from the public. Wind power has been painted like everyone loves it, but all the cases have been appealed.”

Davidge runs Sewall House Yoga Retreat in Island Falls, and often takes her clients to Mattawamkeag Lake. According to the complaint, visitors have said they wouldn’t return if the project is built as now designed.

The citizen group lost an appeal to the Maine Supreme Judicial Court in 2011. That case dealt with an approval of the Oakfield project by Maine’s Board of Environmental Protection. The group was attempting to show in court that the project created an unreasonable impact on scenic and visual values.

“A lot of us who love Aroostook are very disappointed,” Davidge said.

In a related issue, Williams said she is waiting for a response to a letter she sent on behalf of Protect our Lakes to Patricia Aho, commissioner of Maine’s Department of Environmental Protection. The letter requests that the DEP, which issued a state permit for the Oakfield project, require First Wind to reduce the maximum sound level its turbines can make at night to reflect changes in the state’s noise ordinance.

Williams said she hasn’t received a response from the letter, dated Aug. 28. She said she would decide this week whether to write a second letter and threaten legal action.

Tux Turkel can be contacted at 791-6462 or at:

tturkel@pressherald.com