Arlington County Board member Ellen M. Bozman is no stranger to Richard J. Herbst, her opponent for the only seat open on the board in the Nov. 5 election.

Herbst and Bozman have been adversaries before, beginning almost a decade ago when he was a member of a South Arlington civic group that unsuccessfully sued the County Board over its approval of Pentagon City, a 118-acre development near his neighborhood.

This year the two are squaring off again as Herbst, in his first bid for elective office, challenges Bozman, a popular incumbent seeking her fourth four-year term on the board. If Bozman wins, county records show, she will be only the third person in at least 60 years to serve a fourth term.

Both are running as independents, he with the backing of the local Republican Party and she with the endorsement of the county's Democratic Party and the Arlingtonians for a Better County, a self-described nonpartisan political coalition.

"I've never come up with a job I thought was more interesting than the one I have now," Bozman said, explaining why she is again seeking a post that brings with it an $11,578 annual salary, occasional 4 a.m. phone calls from residents and a calendar full of must-attend functions. "I think building a better community is the most important thing to do in the world," she said.

Herbst, a 48-year-old lawyer who has specialized in environmental and patent law and has an undergraduate degree in mechanical engineering, said: "I think I'd do a better job than Ellen Bozman because of the diversity of my professional experience."

Now a policy analyst for Commerce Secretary Malcolm Baldrige, Herbst must run as an independent because the Hatch Act bars federal employes from party politics.

Bozman, a 60-year-old former federal budget officer, has been a familiar figure in the county since the early 1960s, when her involvement with the League of Women Voters launched a career of community activism in desegregation, education, and health and welfare issues.

Today, she is as quickly recognized when she attends her aerobics class or the Arlington Opera as when she sits on the County Board dais or goes into a neighborhood to check out a complaint.

Herbst's community activism mostly has involved South Arlington issues affecting his Arlington Ridge neighborhood and the adjacent Aurora Highlands community, the two residential areas sandwiched between I-395 and Crystal City's Rte. 1 corridor.

He is well known there for his work as a member and former president of the Arlington Ridge Civic Association, roles that often have brought him before the board to discuss issues such as commuter traffic, the county's waste water treatment plant and its trash and sludge incinerators. He says these problems have hurt the neighborhood and that Bozman has not done enough to keep them out.

Herbst acknowledges that his battle to unseat Bozman has been uphill, and he is trying to overcome his lack of a presence outside of South Arlington. Bozman is hoping to raise about $40,000 in campaign contributions, but Herbst said he may have to make do with $25,000 to $30,000.

The campaign has been a low key, noncontroversial one, drawing sparse turnouts at their debates before civic groups.

Herbst stresses his role in neighborhood battles, such as the one over the state plan for an elevated freeway that would have replaced Rte. 1 in South Arlington. His environmental analysis of the proposed road was a factor in the state's decision to kill the plan.

Bozman stresses the need for county services to keep up with demographic changes that have brought demands for more day care centers and programs for the foreign-born and elderly, sprucing up the county's physical appearance, maintaining its low tax rates and motivating technological firms to get involved in county programs.

Herbst says the county must change its policy regulating the number of parking spaces in some buildings because it is based on overly optimistic estimates of the number of people who will use the Metro subway system. He adds that the county must cut taxes even more and improve traffic control and building inspections.

The two agree that the No. 1 issue in the county is protecting residential neighborhoods from high-rise development.

Herbst says his campaign is directed more against the four Democrats who control the five-member board than against Bozman. He maintains that residents "are just not sure which way the board majority is headed" on development.

"They talk about a policy of 'bull's-eye development,' but I'm not so sure they have a clear policy and a way of following it up," he said, referring to the county's plan of restricting high-rises to the immediate vicinity of Metro stops. Building heights then are to taper down to midrises and town houses as they reach single-family areas.

As an example, he cited a 1983 unanimous decision by the board to grant a developer's request for extra density for a proposed high-rise life care facility for the elderly near the courthouse. The firm went bankrupt before the complex was built.

Last month, the board reluctantly approved another developer's proposal for a high-rise residential building for the site because legally it could not lower the density already approved there. Herbst says that although the board was anxious to get a facility for the county's growing elderly population, it should not have granted the extra density for the life care facility.

"First of all," Bozman said, "that land was never zoned for single-family detached residences. It was always scheduled to go high-rise" because of its proximity to the Court House Metro stop and other high-rises planned nearby.

Approval of the facility, she said, backfired on the board, which has asked the county attorney to research possible ways to avoid such problems in the future.

Overall, she said, she is "comfortable that the buffers between high-rises and homes are well in place. We have a good track record on that . . . . People know where the line is" for high-rise development in Metro stop areas.

Herbst is critical of the board's rearrangement last year of densities at a 25-acre shopping center site in the 118-acre Pentagon City residential-office-hotel development adjacent to Crystal City. It was the larger Pentagon City project that Herbst and other neighbors tried unsuccessfully to block in court in 1976.

He says that the board's unanimous vote last year to trade extra retail space at the shopping center for reduced hotel space elsewhere on the tract violated the 1976 agreement and altered plans for more mixed uses on the shopping center site. Bozman says the exchange was fair because the total densities were not altered.

Herbst said the board should have returned more of last year's $4.2 million budget surplus to residents in the form of tax cuts. Bozman notes that the board used $1.4 million to cut business taxes and put the remainder in reserve funds, an action that should free money for possible tax cuts next year.