The nonprofit Arlington Housing Corporation (AHC) has lost its third bid to acquire land to build a low- and moderate-income townhouse development.

In a decision that surprised AHC officials, the County Board decided last week not to sell three acres of land to the corporation for a 32-unit townhouse development. That decision came after an emotional five-hour public hearing at which 30 residents of the Arlington-East Falls Church area testified against the proposal.

Located in a neighborhood of $75,000 homes, the land is part of the Stewart School site near the East Falls Church line. Because of declining enrollment, the school was closed in 1972 and, until recently, was used as a performing arts center.

Opponents presented the board with a petition containing 700 signatures.

The decision marked another defeat for housing proposals sponsored by the nonprofit, federally funded housing corporation created three years ago to generate low- and moderate-cost housing for Arlington.

Previously, the board decided to sell a tract of land in South Arlington in which AHC had expressed interest. The property is now the site of a museum. Last year in the wake of citizen opposition, the board voted against selling AHC a tract of county-owned land near Bluemont Park. That land was later acquired by VEPCO.

The board's most recent decision followed by three weeks announcements expected to result in the depletion of a large part of Arlington's stock of low- and moderate-cost garden apartments. Rehabilitation resulting in rent increases of 50 percent is scheduled to begin at Buckingham Apartments in January. The planned condominium conversion of the 500-unit Claremont Apartments is slated to begin in the next few months.

County officials estimate that as many as 7,000 tenants, many of them elderly, recently arrived ethnic minorities and low-income families, will be forced onto the housing market in a county that has one of the lowest apartment vacancy rates in the metropolitan area.

Under the AHC proposal, most of the townhouses would have been sold to moderate-income families for about $50,000, or slightly more than half the cost of similar nonsubsidized townhouses. Under federal guidelines a family of four making $11,000 to $18,000 per year is considered to have a moderate income. The median family income in Arlington is $18,553.

"We're not talking about public housing," AHC official James Hunter told the board last week. "What we propose is much lower density than the surrounding neighborhood. You're being presented with a very attractive, nonthreatening proposal."

Area residents, about 75 of whom packed the board room, during testimony from several supporters of the proposal.

"This is not a suitable site for a housing project," said Arlington-East Falls Church Civic Association president Robert Ware. "It is not near a shopping center or library."

"We live in a dustbowl and wash and bathe in and drink dirty water and we have cracks in our walls," said Jerry Eyster noting that a Metro station and 166 are under currently under construction in the neighborhood. "(I am) not against subsidized housing, but this county needs all the open space it has."

According to county planning officials, the neighborhood has 16 acres of open space - including the 12-acre Tuckahoe Park - one of the largest concentrations in Arlington.

Some residents opposed the plan for other reasons.

"I thought moving to Arlington from Falls Church was a step up," said Lawrence Anderson.

"My wife and I had to combine our salaries and push ourselves to our financial limit to buy that house and I would resent others" living in the same neighborhood who did not do likewise, Anderson said.

Two officials of the Arlington Education Association endorsed the plan. "Over half the teaching staff in Arlington lives outside the county because they cannot afford to buy homes here," said Marjorie Sale, director of the association. "Many teachers would qualify for these townhouses."

Teacher Michelle Milden noted, "Arlington County has sufficient open space. Those parks may become tent cities because there's no other place to live."

Board Chairman John W. Purdy, in a move that housing corporation officials said surprised them, indicated early in the discussion that he sympathized with pleas for open space.

Purdy voted with board members Dorothy T. Grotos and Walter L. Frankland Jr. against the proposal, which county officials said would also have generated about a half-million dollars annually in tax revenue.

"It's not that we're a snob community," Grotos explained. "I believe the housing corporation will find some areas where there are not 700 citizens against it." Board Vice Chairman Ellen M. Bozman and member Joseph S. Wholey supported the plan.

AHC officials, who say they are squueezed by the high cost and scarcity of land and by citizen opposition, are less optimistic than Grotos.

"We have a problem finding land because there are very few vacant sites left," said Executive Director Lou Ann Frederick. AHC currently has a $450,000 budget for land acquisition. "We're often outbid by developers who want to put up $200,000 townhouses.

"People are fearful of who is going to come into the neighborhood. Some residents in that neighborhood told me that children playing on the Stewart School site were stopped and asked how they would feel if their playground were taken away and thieves and prostitutes came into their neighborhood as a result of our proposal. I assume those who asked them wanted them to go home and ask their parents.

"The night we went to meet with the citizens, on the table with our brochures were pamphlets about how to protect yourself from rape or robbery.

I think people really don't understand the need for this housing. Many families have invested everything they have in their homes. Because of the high cost of housing in the area everyone's on really shaky ground. It's the view that everybody can make it if they try hard enough."

Last May, the county board adopted housing goals, among them the intention to "place major emphasis on meeting the housing needs of low and moderate-income families" and to "review county-owned land with the possibility of donating such land for the development of moderate-cost housing."

County housing officials estimate that residents of about 9,500 households need help and aren't getting it under a variety of federal and local subsidy programs.