The Arlington School Board last night rejected a study group's recommendation to link teachers' salaries with the county's average per capita income and asked the superintendent to study the salary structure further. The proposal would have cost $11.2 million over current spending.

A committee appointed by the county board, the elected body that provides money for the county government, including the schools, had met for nearly a year to come up with the proposal, which was supported by the Arlington Education Association, the teachers' representative. The board had asked that the committee analyze the current salary structure to determine if it was fair and adequate.

Education association President Sara Jane Knight said last night that she was "just amazed" at the School Board's action, adding: "They have no firm commitment to anything. They're like they were before square one."

The proposal would have raised a starting teacher's annual salary from $21,710 to $28,075 and would have pushed the salary of a teacher with 10 years' experience and a master's degree from $41,104 to $56,150.

Committee member Tom Kelly said current teacher salaries are unfairly low and take advantage of a loyal work force of people who will not quit just because they are underpaid. He added that the committee recognized that its proposal was just a starting point in efforts to increase salaries.

"We wanted a proposal which was radical enough to get them talking and reasonable enough to get them to confront it," said Kelly, an official of the U.S. Environmental Protection Agency.

In criticizing the committee's proposal, board members said there was no logical reason to link teacher salaries with Arlington's per capita income, which is one of the highest in the nation. Board member Dorothy Stambaugh said such a proposal would open the door to similar demands by other county employe groups.

Also, Stambaugh questioned the validity of the oft-repeated argument that teachers cannot afford to live in the community in which they work.

"There are a lot of folks who cannot afford to buy the kind of house they want," she said. "They're doctors, lawyers, janitors, secretaries and everyone else." She said that while Arlington is an affluent community, 40 percent of the schoolchildren are poor enough to receive federally subsidized lunches, "and they can afford to live in Arlington."

In its investigation, the committee, which was made up of three residents, three teachers and two administrative staff members, found that since 1970 teachers' salaries have failed to keep pace with the consumer price index and that a teacher in 1987 has less purchasing power than a teacher with identical qualifications had in 1971.