The Fairfax Board of Supervisors yesterday approved a public housing project for one of the county's oldest black neighborhoods, despite organized opposition from wealthier surrounding communities.

The county's housing authority will now begin developing the $6 million, 105-unit West Ford town house project in the Gum Springs neighborhood near Mount Vernon. The project is named for the freed slave who in 1832 purchased the Gum Springs land, which had housed the slave quarters for George Washington's plantation and which remained without sewers and running water until the 1960s.

The board approved the project only after rejecting by a 4-to-4 tie vote a motion by Board Chairman John F. Herrity (R) to delay it. Herrity, a longstanding critic of the housing authority, said the agency had not held the required public hearings and had not provided the board with enough information. Republicans Marie Travesky, Nancy Falck and Thomas M. Davis III supported a delay, while Democrats Sandra L. Duckworth, Martha V. Pennino, Audrey Moore and Joseph Alexander voted no. Democrat James Scott was absent.

Fairfax County, with more than 600,000 residents and fewer than 600 public housing units, is accustomed to fights over proposed subsidized projects, and supervisors reported receiving hundreds of letters and telephone calls on both sides of this issue. The Gum Springs debate was unusual, however, because the immediate community favored the project.

In addition, Supervisors Travesky and Duckworth rallied strongly to the unpopular concept of public housing. "Any of us who have VA or FHA mortgages really have subsidized housing," Travesky said.

Some residents of newer and more affluent communities around Gum Springs said the West Ford project would attract poor people from outside the area rather than serving Gum Springs itself. "We are convinced that this development will result in a further influx of low-income people into the area," Allen Vander Staay, president of the 197-home River Farms civic association, said in a prepared statement.

Vander Staay said he favored rehabilitation of the dilapidated single-family homes in Gum Springs, but he said income limits will keep most Gum Springs residents from moving into the town houses. To be eligible for the new homes, a family of four could earn no more than $20,000 a year.

Marie Saunders, a third-generation resident of Gum Springs, said nearby homeowners opposed the project "because we're black. . . They think we'd be pulling in a bunch of welfare people." Saunders, whose builder-husband is a fourth great-grandson of West Ford, said she can remember picking blackberries and being chased by a bull on the land where Vander Staay's River Farms community opened in 1977. "I'm not going to let them run us out the way that old bull did, not this time," she said.

Vander Staay and others said they opposed building large concentrations of subsidized housing, but not on racial grounds. "Unfortunately, it became obvious that to oppose these rezonings labeled you at least a white snob," Vander Staay said, referring to the "intimidation job" that he said Gum Springs leaders organized at a planning commission meeting last week.

About 1,200 families live in Gum Springs, with 400 households in the central, urban renewal area, according to county officials. In 1979, three-quarters of their homes were in need of substantial repair or rehabilitation and most homeowners could not afford the work, the officials said.