The leader of the Alexandria teachers' association went before the school board last week to voice concerns about declining staff morale, in the wake of plans by school administrators to tighten their system of evaluating faculty members.

"We are demoralized by all this talk about 'bad teachers'," said Hazel Rigby, president of the Education Association of Alexandria, which represents most of the 700 teachers in the school system. Rigby called the stricter evaluations a form of harassment undermining teachers' efforts to concentrate on their work.

Superintendent Robert W. Peebles, who spearheaded the adoption of the new evaluation system, said later the evaluations are meant not as a threat to teachers but as a way to improve the educational system in Alexandria. And both the board and school administrators indicated they did not plan to abandon the stricter evaluations.

"I would say these evaluations are helping improve our teaching staff," school personnel director John E. DuVall said after the meeting. "I think they are supported by teachers. No one wants poor performers as colleagues. It pulls down the quality of the whole system."

DuVall said Alexandria has always had teacher evaluations, but has focused more strongly on them under Peebles' leadership. This year, DuVall said, evaluations will be even more extensive, with a computer randomly choosing teachers for 'classroom audits,' in which observers check some classrooms to make sure teachers are adhering to the outlined curriculum and are teaching it effectively.

For the past several years, Alexandria has been plagued by poor achievement scores, which have shown its students below the national norm in reading, writing, science and math. National educators have said improving teachers' performance and ensuring they stick with an established curriculum can improve educational systems.

Peebles said the evaluations are a positive measure designed to pinpoint weak teaching skills and help teachers improve those skills.

At the board meeting, however, education association president Rigby said poor communication between administrators and teachers has left many teachers confused about the new evaluations. She added that some teachers fear the evaluations could be used next year if layoffs are needed.

"The word I've heard around the schools is 'fear'," Rigby said. "Increasingly, the administration, the school board and even City Council members have chosen to take on the teaching staff as responsible for whatever problems they see. It is demoralizing. It undermines our ability to teach."

Last week, for the first time in six years, the school board voted to fire a tenured teacher for poor teaching performance. Peebles said the dismissal was not meant as a warning to other tenured teachers, however.

"This is not a big brother operation," he said.

But Peebles added: "There is a feeling that once you have tenure, forget about your performance.

"It's so easy to say, 'You've got bums, get rid of them.' The first half may be true but the second half is harder to do.

"I would say that 95 percent of our teachers are competent," Peebles said. "We want to help the others improve."

The discussion of evaluations came as the school board set its goals for the coming year, goals the board has been hammering out over the past month.

In addition to increased evaluations, those goals include an extensive review of enrollment patterns, with the possibility of school closings sometime in the future.

Although closings are not expected in the immediate future, said board Chairman Lou Cook, a recent report estimates the school system enrollment by 1985 will be 8,622. This year, there are an estimated 10,200 students (final figures have not yet been tallied), compared with a peak-year enrollment of 17,498 in 1970.

"It (possible closings) is a touchy issue," said Cook. "We're going to have to look at attendance, boundaries. We want to sit down and draw up a long-range plan based on all the information available.

"Parents should be assured, we won't do anything without community input."

One of the reasons the school board may be looking into school closings is because City Council members, who control the school budget, have long hinted such closings will save the system money. Peebles said last week there has been no direct request from the council to look into the matter. "But it has been discussed informally," he said. "I would say it's on their minds. We are obligated to look into it."

Peebles said it will take time to study the problem, however.

"I will say it could be we won't close schools because that may not be in the best interest of the school system," he said. "Just because we're looking at it doesn't mean we're going to do it."