The Environmental Protection Agency overstepped its authority in trying to regulate water flow to protect the habitat of worms, snails and insects in Accotink Creek, Fairfax County officials charge.

Fairfax is the latest community to sue the federal agency over storm water runoff standards that local officials said could cost hundreds of millions of dollars to meet and may do little to benefit the worms and bugs.

"It's all about the bugs," said Dan Wichmer, city attorney for Springfield, Mo., another community that has sued the EPA over the storm water rules.

EPA officials want to reduce storm water flowing into the Accotink Creek watershed by 50 percent to cut down on sediment and protect organisms living in the creek. Fairfax officials said the agency doesn't have the authority to order those changes, which they estimate would cost the county between $110 million and $215 million to implement.

"We might as well take the cash and drop it into the bay," Supervisor Penny Gross, D-Mason, said.

Fairfax County, along with the Virginia Department of Transportation, has sued the EPA to reverse its decision, charging that the federal agency is violating the Clean Water Act.

James Patteson, Fairfax County's director of Public Works and Environmental Services, said the EPA's goal of improving life in the creek by reducing its flow may be unattainable, and so the county wants to ensure that the federal orders "do not set us up for failure."

The 50 percent reduction in water flow that the EPA wants would "shut down any and all improvement" in the watershed because of possible restrictions placed on home and property owners, Supervisor Pat Herrity, R-Springfield, said.

EPA spokesman David Sternberg defended the agency's action, saying it is acting within its authority.

The Springfield lawsuit against the EPA is still in court, Wichmer said. Another suit filed by Columbia, Mo., was settled, city officials said.