Environmentalists have won a court order forcing federal officials to take a more aggressive role in protecting hundreds of Virginia waterways from pollution.

The order could lead to a major cleanup of rivers and the Chesapeake Bay and to rebounding populations of fish and aquatic plants, environmentalists say. W. Michael McCabe, the Environmental Protection Agency administrator for the mid-Atlantic states, praised the agreement as well.

"This is good for water quality," McCabe said.

The order by U.S. District Judge T.S. Ellis III of Alexandria ratifies a settlement between the EPA and two environmental groups that filed a lawsuit against the agency. The suit said the EPA was not enforcing provisions in the 1972 Clean Water Act that require Virginia officials to develop maximum pollution levels permitted in state waters.

Virginia environmental officials said they were studying the settlement but offered no detailed comment on it.

Similar lawsuits have been filed in more than two dozen other states and nearly half of them are now settled. Suits in Maryland and the District are still pending.

Critics say the EPA settlement of the cases could lead to unnecessary intrusion by the federal government and give the agency power to dictate land-use patterns and economic development.

"They will have the authority to determine who develops and who doesn't," said Don R. Parrish of the American Farm Bureau Federation. "To live is to pollute, right? Everybody flushes a toilet. . . . Everybody has to work and live in a home."

The lawsuit affecting Virginia was filed by the American Canoe Association, based in Springfield, and the American Littoral Society, based in New Jersey.

Ellis's order requires federal oversight of the amount of pollutants allowed in Virginia's "dirty waters," a list of more than 800 waterways including the state's portion of the Chesapeake Bay and its tributaries.

Virginia environmental officials had already agreed to establish these levels, but the court order sets a more stringent schedule for compliance in the next decade. If state officials failed to meet that schedule, the EPA would step in, setting maximum levels for pollutants and ensuring compliance by factories, farms, sewage-treatment systems and other significant sources of water pollution.

The Virginia Association of Municipal Wastewater Agencies objected to the court order on the grounds that it allows the EPA to overstep its authority. The group is considering an appeal to the 4th U.S. Circuit Court of Appeals in Richmond, said its lawyer, David Evans.

"The state of Virginia has been very responsible, has done everything EPA asked of it," Evans said.

Environmentalists disagree.

"The reality is that Virginia, along with other states, has been recalcitrant in developing" maximum pollutant levels, said Ray Hoagland of the Chesapeake Bay Foundation.