After three years of controversy, Loudoun County appears to be close to approving a proposal to expand a rock quarry near Manassas National Battlefield Park.

The proposal to expand Bull Run Quarry has aroused opposition by many nearby homeowners and the National Park Service, which have contended that expansion would create undue noise, vibrations, dust and flying rock from the blasting and crushing operations and would adversely affect water wells in the area. Residents, along with the Park Service, also are concerned about heavy traffic from the quarry.

The county planning staff has endorsed the proposal, with certain restrictions, saying the proposal would generate increased revenues for the county and that relatively few residents live near the quarry.

"We have no dollar figure . . . but the quarry will generate more money than its costs," said county zoning administrator Michael Congleton.

The new 66-acre quarry site is about half a mile from Manassas Battlefield at the southern end of Loudoun near the Prince William and Fairfax county lines.

Nearly 75 people turned out last week for the latest in a half dozen public hearings before the Board of Zoning Appeals, which is expected to hold its final hearing on the issue Oct. 21. A decision is expected sometime after that.

The present quarry operation, begun in 1955, is expected to run out of extractable rock and be closed down within the next year or two, according to quarry owners and county staff reports.

Residents argue that what once was a small "mom and pop" quarry is being turned into a major nuisance industry in a residential zone, despite repeated assurances over the past 25 years from county officials and owner Nathan Bolling that the operation would not be expanded.

Bolling declined to discuss the issue. However, his attorney, Thomas Nalls, said, "There's no way in the world" Bolling would have made such promises to his neighbors.

Several neighbors, including Bolling's former maid, who lives across from the quarry, testified last week against the expansion.

"I worked for him Bolling for 10 years . . ." said Bessie Allen, "and Mr. Bolling told my father he'd come no closer than where the present quarry is."

She said she had no objection to the present quarry because she thought it would close in a few years, but "in the name of Jesus we're asking you not to come up in front of our house . . . 500 feet away."

Several residents complained that blasts from the existing quarry have damaged buildings, and that the new operation would bring blasting even closer. However, county officials as well as geological consultants hired by Bolling contend none of the damage has been linked to the quarry.

One resident, Judy Cosby, said the county had assured residents the quarry would not expand.

"In 1964 an attempt to rezone land around the quarry failed, was unanimously rejected by county boards," she said. "We felt secure and trusted in the county and our zoning. . . .

"If you don't protect us now, there is no zoning protection for anyone in the county. . . ."

Several residents accused the county of interpreting various county ordinances to benefit the Bull Run Quarry and three others in the county.

At last week's hearing, Zoning Chairman James M. Purks repeatedly asked residents if they had "anything in writing" to prove that Bolling or county officials ever promised that the quarry would not be expanded.

"A number of people have said that but there is nothing to back it up," Purks said.

William B. Hanes, an attorney representing the Bull Run Civic Association, contended, however, that the promises are valid. "What you're going to have to conclusively find is that the whole neighborhood is a bunch of liars," Hanes said.

In recommending approval of an special exemption that would allow the quarry to expand, county officials have proposed restrictions they say will ease the impact of the expansion, including a buffer zone along Rte. 659, limits on hours of operation and truck traffic and a guarantee that Bolling will replace any wells of nearby residents that run dry because of the expansion.

Although Bolling is asking for a special exception until the year 2010, the county staff is urging a seven-year test period to ensure that the quarry creates no problems. Quarry traffic would be limited to roughly the present level, or 750 vehicles a day.

Residents contend, however, that level of traffic already is too great and hurts home values in the area as well as detracting from the Manassas Battlefield.

Battlefield Superintendent Rolland Swain told the zoning board that there have been complaints about the gravel trucks from a number of the 800,000 people who visit the park each year. The Park Service previously had complained to the county that quarry trucks speed on the narrow two-lane roads , occasionally running traffic lights, and that loose gravel spilling from the trucks has damaged visitors' cars.

Quarry attorney Nalls said he believes residents' concerns may be somewhat exaggerated, but said the county-proposed restrictions, if modified, "would make [the quarry] a better operation" than it has been for the past 25 years.