Virginia's most ambitious attempt yet to clean up the Chesapeake Bay, a program to reduce construction pollution from Tidewater to the Washington suburbs, is stalled by a developer lawsuit and tardy local response.

Virginia's program, like Maryland's Critical Areas legislation, clamps tighter rules on development on fragile lands to reduce runoff pollution to the bay and its rivers. Either construction would be banned or new precautions would be required to curb soil erosion and flooding.

The 1988 law creating the program, the Chesapeake Bay Preservation Act, drew complaints from property owners and local officials that it robbed their land-use rights. Conservationists called the law a good start, but said it depended too heavily on enforcement by local officials who did not necessarily want a tough program.

The bay program is now in limbo because a York County judge, responding to a developer's lawsuit, ruled Sept. 19 that a state board adopted the rules implementing the law a day before the end of a public comment period last year.

The 89 cities, towns and counties covered by the law were supposed to submit local regulations to the state for approval by Sept. 20. Only 25 have done so, and the only Northern Virginia jurisdiction to comply has been Fairfax City. Environmentalists say some local plans are too weak to protect the bay.

State officials say delays in submitting local plans are understandable because the law is so complex, but critics are troubled.

"They ought to start some leaning on this thing," said state Sen. Joseph V. Gartlan Jr. (D-Fairfax). "Everybody had ample time, ample notice and even monetary assistance."

Gartlan said he suspects some localities are stalling in hopes the law will be weakened in next year's General Assembly. Already, Prince William County officials plan to lobby the state to allow recreational uses such as golf courses to be located near streams, which the law severely limits because lawn fertilizer is a pollutant.

Officials of the Chesapeake Bay Local Assistance Board, which oversees the law's implementation, are hopeful the judge's ruling can be remedied easily, because it did not overturn the law itself. But they concede it forced them to suspend sending hurry-up letters to the late localities.

The impact of Judge G. Duane Holloway's ruling is up in the air. He asked the two sides to draft an order implementing his decision, but they could not agree on the wording, so he will hold another hearing Nov. 7.

The bay law is designed to reduce development and agricultural runoff that carries millions of tons of dirt, toxics, nitrogen and phosphorus to the Chesapeake and the network of streams and underground springs that flow to it. Those pollutants cloud the water, smother aquatic life and fuel growth of algae that choke off other species.

Localities must designate their land into one of three categories: Developed; shoreline or major wetlands where most construction is banned; or environmentally sensitive, where new construction must take stronger steps to curb stormwater runoff, reduce erosion and prevent septic system failure.

On sensitive land, stronger steps would be required of projects larger than 2,500 square feet -- the size of a large home addition or a small industrial building -- potentially requiring some homeowners to file site plans for the first time for major renovations. State officials say the law adds $1,400 to $4,500 to the cost of a new $150,000 house.

In Prince William County, the Planning Commission voted last week to reject a staff proposal to declare virtually the entire county as sensitive land. Responding to builder complaints that the rules would impose economic hardship for no good reason, the commission reduced the acreage of protected land dramatically. County supervisors are to vote on the plan next month.

Frank Milligan, Planning Commission chairman, called the staff proposal overkill because it did not discriminate among different properties. "My concern was fairness," he said.

The commission acted against the advice of Jared Florance, county health director, who warned that the county needed the added protection against septic system failure.

Fairfax County supervisors postponed a vote Oct. 15 on setting a timetable for adopting local rules, but ordered staff members to produce proposed rules by Friday for the state to review. Supervisors said they hope to approve rules by February after public hearings.

The state law gives local government broad discretion on how much land to shield from development, handling hardship cases and setting standards for new construction.

Local plans thus vary widely. The Fairfax County staff proposed that the entire locality fall into the two most protected categories. Virginia Beach tried to designate nearly all its area as already developed, thus subject to the most lenient rules, before state officials objected.

Alexandria and Arlington officials are awaiting up-to-date wetland maps, expected by November, before adopting rules. Planners in both places are expected to propose the entire locality be designated as environmentally sensitive. The law does not cover Loudoun County.

Virginia's law has a similar aim as Maryland's 1984 Critical Areas law, but environmental groups consider Maryland's law tougher because it applies more specific controls on construction within 1,000 feet of the bay and its tributaries in most of the state. Virginia's law covers entire counties, but only in eastern Virginia and it gives localities considerable flexibility.

Staff writer Whitney Redding contributed to this report.