Fairfax County Supervisor John W. Foust cast the lone vote against filing a lawsuit against the U.S. Environmental Protection Agency this week — but not because he thought the county wasn’t justified in taking legal action against the federal government.

John W. Foust (John W. Foust)

But Faust, in an interview Friday, said he objected to filing a joint lawsuit with the commonwealth of Virginia because he worried that Attorney General Ken Cuccinelli (R) — who became a national hero to conservatives by sparring with the EPA over other cases and suing the federal government over President Obama’s health-care overhaul — would wield the new case like a political weapon.

But after reading the complaint filed Thursday by the county and the attorney general, Foust said his fears have been allayed for now.

“I read every word. It’s very well done: just the facts,” Foust said.

The state and county, in the lawsuit filed Thursday, accused the EPA of “massive” and expensive overreach in its attempts to control sediment buildup in the Accotink Creek watershed.

Board of Supervisors Chairman Sharon S. Bulova (D) said the board put aside politics to do what was best for county citizens. They filed a joint lawsuit with the state to increase their firepower in challenging regulations that could cost the county hundreds of millions of dollars, she said.

But the decision by the Democratic-led Board of Supervisors to team with Cuccinelli to sue the EPA raised some eyebrows. Ben Tribbett, who writes the liberal NotLarrySabato blog, fired off a tweet saying: “@KenCuccinelli and @SharonBulova teaming up to sue the EPA? Say it ain’t so Sharon.”

Foust (D-Dranesville), who is a lawyer, was the only supervisor to vote in closed session Tuesday against suing the EPA.

Foust said he objected because he did not want to be a co-plaintiff with Cuccinelli’s office because he believes Cuccinelli has initiated politically motivated cases in the past. Foust also said he felt the county would be better able to control its destiny in the legal action by filing a separate lawsuit.

In asking for declaratory judgment and an injunction, the lawsuit argues that the EPA’s proposed restrictions on water flow exceed its authority under the Clean Water Act and would divert public funds that could be spent more effectively on restoring Accotink Creek. They said the EPA would require the county to cut the flow of water by half at a cost that could reach as much as $500 million.

The state and county say that although the EPA has the power to regulate the discharge of pollutants, including sediment, the agency last year issued a restoration plan — known as Total Maximum Daily Load (TMDL) — that would require the county to control the quantity or flow of water itself in Accotink Creek to improve aquatic life there.

“EPA is literally treating water itself — the very substance the Clean Water Act was created to protect — as a pollutant,” the lawsuit says.

An EPA spokeswoman said the agency is currently reviewing the lawsuit.

“The Agency established this science-based TMDL to ensure the health of the Accotink Creek,” the spokeswoman said. “The TMDL is supported by sound science and well within our authority under the Clean Water Act.”