The Fairfax County Board of Supervisors on Tuesday directed county staff to account for the potential environmental impacts of allowing an industrial landfill in Lorton to operate until 2040.

The unanimous decision, which occurred after a lengthy discussion, was as much about acknowledging controversy surrounding a proposal to use the landfill as a hub for green energy technology as it was about concerns over groundwater and other potential impacts.

After agreeing five years ago to close the site by 2019 and leave behind a 162-acre rural park, the landfill’s owner, EnviroSolutions, is now seeking permission to broaden the mountain of construction debris and keep it open another 22 years.

In turn, the company is proposing to help the county build a “Green Energy Triangle” in Lorton that would include wind turbines, solar panels and geothermal piping — plus $18.2 million for recreation and other services in the surrounding area.

Although the proposal would still be subject to a mandated state environmental review if the county approves the company’s application, Supervisor Gerald W. Hyland (D-Mount Vernon) proposed a preliminary assessment of the project that is in his district.

The project faces fierce opposition from homeowners groups and civic associations in the rapidly changing Lorton area, although other groups and some county supervisors support it.

“I think the board should have an answer to this question before we take any action on this application,” said Hyland, citing a request for an environmental review by the Sierra Club in a 2012 letter that also expresses support for the proposal.

Taking in between 650,000 and 1 million tons of industrial waste per year, the landfill is near Occoquan River and Mason Neck State Park — a concern for some who worry about bald eagles and other migratory birds flying into the proposed wind turbines.

State environmental inspection reports show some problems with leaching and excess metals on the landfill site, leading to minor fines over the years.

But the site that Manassas-based EnviroSolutions has owned since 2004 has consistently passed annual inspections, records show.

A county staff report on the project, which will now include an environmental review, is expected to be released by Friday, officials said.