At Fairfax Station, a subdivision south of Fairfax City, the bulldozers have stopped, awaiting the resolution of a court battle over one of Northern Virginia's most ambitious efforts to control growth.

At stake are not only plans to finish the subdivision partly owned by developers John T. Hazel Jr. and Milton V. Peterson but development itself in a quarter of the county.

Also at stake, say environmentalists, is the water supply for 600,000 Northern Virginians.

Landowners have brought out their big legal guns for this battle, a complicated court case over the county's plan to "downzone" in the Occoquan watershed, a plan some see as the county's last-gasp effort to preserve some sparsely developed parts of Fairfax.

"Literally hundreds of property owners" will be affected, according to Marc E. Bettius, who is representing Aldre Properties Inc., a major landholder in the area.

Under the Occoquan downzoning plan, development limits were changed from one house an acre to one house per five acres, building restrictions were imposed in some noisy areas near Dulles International Airport and certain measures were mandated to minimize pollution of the Occoquan Reservoir, which supplies drinking water for much of Northern Virginia.

The Occoquan battle is only the latest chapter in the county's long struggle to control growth, an effort sparked by fears that the traffic congestion, pollution and other suburban ills of eastern Fairfax, Arlington and Alexandria would spread west.

That struggle has been an uphill fight, as county officials bumped up against unsympathetic state courts, powerful developers and an attitude that the momentum of development that has built up over more than two decades is difficult to reverse.

The potential for failure in this particular case is especially upsettling to some development foes because near the designated no-growth region lies a smaller area, known as the Fairfax Center Area, that is slated for intense development.

Supervisor Audrey Moore (D-Annandale) says the county should not proceed any further with plans to create a commercial and residential "urban village" near I-66 and Rte. 50--the Fair Oaks Mall area--until the Occoquan issue is resolved in court.

But the other supervisors have argued the board legally cannot tie the two issues together.

Meanwhile, the Fairfax Center Area plan is stalled with problems of its own. Virginia transportation officials believe the cost of road improvements needed to prevent Tysons Corner-style traffic headaches will be $65 million rather than the $52 million originally estimated by county staffers.

That has raised new questions over whether the formula for assessing the developers, which could raise $39 million for road improvements, is adequate.

The board already has decided the county taxpayers should not foot the entire bill for the transportation improvements but is still wrestling with the question of exactly how much the public should pay. Into this pot must go the fact that many Fairfax officials expect the county to be sued over the unique financing plan for the I-66-Rte. 50 area.

Despite these legal and financial question marks, the Board of Supervisors already has approved rezoning requests for two town house developments. The supervisors put off action on a larger and more controversial application by developer Hazel for a 588-acre commercial and residential development, presumably until after the election.

"I think the granting of those two rezonings in 50-66 is going to be used against the county" by the developers in the Occoquan cases, Moore said. "The board should have held off on them."

Thirty-four property owners sued the county after the board approved the downzoning plan on July 26, 1982. They argued the county deprived them of their right to use land they already had invested in and, therefore, the ordinance was unconstitutional.

Bettius also argues the Occoquan plan was based on a "pretended water crisis." Bettius says it is farms--not houses--that pollute the water supply with phosphorus, to which Moore replies, that sewage and urban runoff are well established sources of water pollution.

The landowners are represented by an impressive group of some of Fairfax's top development lawyers, with the brash Bettius leading the charge.

Some supporters of the Occoquan downzoning say privately they fear the county's overworked attorneys will be outmanuevered by the highly paid legal team across the aisle. Already they fret over the fact that, of the four cases the judge has agreed to hear initially, the lawyers for the landowners got to select three.

The cases are not scheduled to be heard until this fall, and whoever loses is expected to appeal.