Some residents living within a mile of Loudoun County's landfill want the county government to compensate them for possible declines in land value attributable to their proximity to the dump.

They told a committee of the Board of Supervisors last week that just the perception that the area's ground water may be contaminated by the garbage disposal facility may cost them money if they try to sell their houses. Conflicting claims about well water quality in the area have surfaced in the last year.

Many of the more than 100 families who live within a mile of the dump moved to their houses after the landfill opened in the early 1970s. However, some say they bought the houses based on the belief that the landfill would close soon.

Members of the Board of Supervisors' Public Services Committee made no commitment to the payments but urged the full Board of Supervisors to establish a committee of citizens and county officials to negotiate an agreement that could lead to such outlays.

The residents propose that the county compensate landowners who can show they cannot sell their houses and land for what they would be worth if they were not close to the landfill. The maximum payment would be 10 percent of the estimated value of a property.

Loudoun Engineering Director Terrance Wharton said the staff favors the concept of the payments, but members of the Public Services Committee were unwilling to attach a binding commitment to a county application for state approval of a 15-acre expansion of the landfill.

"We'll have to come up with a rebuttal" to the argument that people who moved close to the dump after it opened might not deserve county compensation, said Russell James, an unofficial spokesman for nearby residents.

The landfill, nearly three miles south of Leesburg along Route 621, is expected to reach capacity and stop receiving trash during this decade. The county recently decided to place a new dump next to the current landfill and its 15-acre expansion.

That decision will reinforce the identity of the current site as a landfill and dissuade potential buyers of land in the area, even when the current dump becomes inactive, James said.

"All citizens should pay for it" when a public facility cuts private property values, said developer Bernard Carlton, who owns land near the dump.

The new landfill is not a foregone conclusion. The state government would have to approve it over objections of the Federal Aviation Administration and some pilots who fear that birds attracted to garbage could collide with aircraft.

In addition, it takes a minimum of a year to get state approval for a locality's application to open a dump, though Loudoun officials have begun to buy about two dozen properties even before submitting their application.

Area residents came up with their proposal to be compensated for possibly reduced land values because, "Let's face the facts . . . . The landfill's going to be there," James said.

They have proposed that a committee of residents and officials be empowered to operate the landfill and that the county government institute a vigorous program of testing water wells for contamination.

County Attorney Jack Roberts said last week that the supervisors may not have the authority to delegate operation of the landfill to citizens and that the current Board of Supervisors may not be able to commit future boards to make payments to property owners.