SPOKANE, Wash. (AP) _ The Environmental Protection Agency has sued Kaiser Aluminum & Chemical Corp. for allegedly violating pollution standards at its Trentwood plant east of Spokane.

If found liable, the company could be subject to civil penalties of as much as $25,000 per day of violations for each of eight emission points, EPA's regional office in Seattle said in a news release.

A Kaiser spokeswoman, Susan Ashe, called the complaint, filed in U.S. District Court in Spokane, ''totally inappropriate, completely unnecessary and most regrettable.''

According to the civil suit announced Wednesday, the federal government seeks a permanent injunction against Kaiser prohibiting violations of visible emissions standards caused by releases of particulate matter.

Also sought is an order directing the Trentwood plant to comply immediately with clean air regulations developed by the Washington Department of Ecology and approved by EPA, said EPA regional spokesman Bill Jacobson.

The complaint accuses the Kaiser plant of exceeding emissions standards for particulate matter ''on numerous occasions since 1984.''

The Trentwood plant rolls and ships such products as beverage can lids and heat-treated sheets, plates and coils.

In 1985, EPA sent Kaiser a formal notice, giving the company 30 days to correct the problem, said Jacobson. The complaint alleges that smoke stacks from the same plant furnaces continued to violate federal and state standards after the 30-day grace period expired.

Ms. Ashe, the Kaiser spokeswoman, said in a prepared statement that the company has spent nearly $500,000 ''redocumenting that particiulate matter within these occasional bursts of smoke from our remelt area were well below every health standard by which one measures.''

Kaiser also announced last month that it would install $1.8 million in pollution-control equipment to reduce emissions from the casting area.

Since the regional EPA office was aware of these steps, Kaiser was shocked when the civil suit was filed, Ms. Ashe said.

In essence, the debate centers around the so-called ''opacity standard'' developed by the state. Industries are restricted in the amount of time that their smoke stacks can exceed 20 percent opacity - basically, seeing 80 percent of what one should be seeing.

EPA uses that opacity standard as an indicator of how much particulate matter is in the air. When an opacity standard is violated, EPA assumes that the federal particulate air standard is violated as well.

Kaiser and others have argued that opacity standards do not truly measure the health or environmental impact of material escaping from stacks. EPA contends the opacity standard is the best available way to measure particulate matter.

Ms. Ashe said Kaiser has been working in good faith in the past year with the county Air Pollution Control Authority, the state Ecology Department and the regional EPA office on an equitable solution to what it calls ''an arbitrary visual emissions standard that has no relation to scientific fact or to health.''

The aluminum company had also sought a local variance and a change in state law to permit any industry or regulatory agency to undertake studies that would lead to the establishment of a scientifiically sound standard.

''We suspect that this regrettable decision (to sue) by the Department of Justice was reached in Washington, D.C. without even checking at the state and local level to find out how much progress has been made,'' Ms. Ashe said. ''Someone far removed from the scene appears to just want to chalk up a mark on the wall as an enforcement undertaken.''

Jacobson, however, said the civil action originated in EPA's regional office in Seattle.

''It was our idea. We pushed it and there was concurrence from headquarters,' ' he said.

Ms. Ashe said Kaiser would seek to meet with all the parties involved in an attempt to settle the dispute. If that fails, the company is prepared to vigorously contest the action in court, she added.