Fairfax County is expected to move a step closer next week to purchase of 119 apartments in Jefferson Village, a dilapidated complex of 70 buildings on Rte. 50, for use as desperately needed public housing.

At its Monday meeting, the county Board of Supervisors is expected to schedule a public hearing and authorize the Redevelopment and Housing Authority to sign a preliminary agreement with the complex owner, according to Supervisor James M. Scott, who represents the district in which Jefferson Village is located. Purchase of the units could not be completed until after the hearing.

An estimated 3,000 low-income families are on waiting lists for subsidized housing in the county, according to a spokeswoman for the Redevelopment and Housing Authority.

The authority originally hoped to buy all of the 512 units in Jefferson Village, located on 35 acres across the road from the Loehmann shopping center. It will use $3.3 million in federal public housing funds to purchase and rehabilitate the 119 units for public housing.

Last month, the agency devised a plan to buy the remaining 393 units with $10.4 billion to be provided by its own bonds. The proposal called for renovation of these apartments over time, with the units to be rented at prices the present occupants could afford, said Deirdre Coyne, community liaison for the housing authority.

Coyne said many of the Jefferson Village tenants could qualify for assisted housing, although they are now paying rents "in the middle to high 300s." The residents, many of them Asian and Hispanic immigrants, often pay half or more of their income for rent as a result.

"We were hoping to operate at a break-even point, but without subsidies we just couldn't do it," she said. No subsidies were available, and high interest rates and other costs put this plan beyond the financial reach of the housing authority.

Scott said the county believes the $10.4 million price for the 393 units is too high and is negotiating for a lower figure with Marshall B. Coyne, Washington hotel mogul and principal owner of Jefferson Village.

While the negotiations proceed, the housing authority is looking for other means of rehabilitating the apartments, said Deirdre Coyne (no relation). One possibility is to offer some tax-exempt financing to a private developer who would purchase the apartments. The developer would agree to skew the rents so that 20 percent of the apartments would be at a level that low- and moderate-income citizens could afford, she said.

Another option, she said, is to persuade a developer to buy and convert the units to condominiums. The housing authority then could provide mortgages for moderate-income families at "a few points lower" than the interest rate for conventional loans.

Housing officials have discussed these proposals with several developers, "who have expressed some interest, but not much enthusiasm. The market is still uncertain," she said.

Still another possibility is for the housing authority to buy the 119 apartments for public housing, and wait until the market improves before acquiring the remaining units, she said.

Most of these plans have drawn fire from a citizens' task force whose members expressed fear that the housing authority will do a "halfway job."

The task force members, made up of residents of Jefferson Village and surrounding communities, support the proposal for 119 units of public housing. They also "feel that all of Jefferson Village should be rehabilitated and remodeled," according to Herbert A. Doyle Jr., the group's co-chairman. "In other words, we want all 512 units to be fixed up and made into decent houses, not just 119."

Other critics want the housing authority to scatter the public housing units throughout the apartment development, because they object to "clusters" of public housing.

The housing authority's Coyne said federal regulations and financing needs make the scattering of units difficult, and that lengthy delays could jeopardize the federal money.

She said she also believes that low-interest mortgages for families and tax-exempt funds for developers should not be considered subsidized housing.

Coyne and other housing advocates insist that the county's need for assisted housing is urgent. About 5,000 units of subsidized housing of all types now are operated by the authority and private groups in Fairfax, including nearly 570 units of public housing. All the subsidized units are full, and an estimated 3,000 families are waiting for space.