A Frederick County Circuit jury yesterday ordered Eastalco Aluminum to pay $65,500 in damages to three local farm families whose dairy cattle were harmed by the plant's fluoride emissions.

In a decision described as a compromise by one of the jurors, the panel declined, however, to award the farm families any damages for what they claimed was the personal discomfort and annoyance theyhad suffered from Eastalco's emissions of fluoride and other pollutants.

The jury also rejected a claim that the aluminium smelter had substantially interfered with the families' abilities to operate their farms.

"We're relieved that they favored us and believed enough in the fact that there were damages" to make an award, said Mary Ann Putman, a member of one of the families that sued Eastalco. The company opened a plant in the argicultural valley in 1970.

Both sides claimed victory in the case -- the farm families because they said that the jury "believed that Eastalco did what we said they did" and the company because of the reduced size and scope of the award.

Originally the families had asked for $1.6 million in compensation and $3.2 million in punitive damages. Judge Samuel W. Barrock had ruled earlier in the trial, however, that there could be no punitive damages because there had been no demonstration that Eastalco acted with malice.

The case, in which the farm families charged that fluoride emissions from the aluminum smelter had damaged their dairy herds and reduced milk production, was one of a number of similar legal acions across the nation in recent years pitting the economic interests of farmers and ranchers against industry in disputes over pollution.

Because farmers and ranchers can claim damages and make pollution costly, theses suits have been an effective new type of environmental action, according to federal officials and environmentalists.

The families "feel vindicated," said their attorney Arden E. Shenker after the verdict yesterday. "They weren't really nuts after all. The cows were getting damaged," he said.

The president of Eastalco, however, interpreted the verdict differently. "Our interpretation is that the jury's opinion totally absolved the company of any wrongdoing," said Harvey Armintrout. "We are and can and will continue to live and operate in the state of Maryland, Frederick County, without harm to our neighbors," he said.

Armintrout said he believed the verdict reflected that the jury felt there should be some compensation for cosmetic damages to cows teeth which he blamed on circumstances before new emissions control equipment was installed in 1975. He said that he believed that the jury had accepted Eastalco's contention that there had been no economic damage to the cattle.

During the panel's 13 hours of deliberations, the jury sent a question to the judge asking whether the claim for damage to the cattle herds and their milk production could be split into two parts. The answer was that there could be only one award but that it could cover other types of damage in addition to reduced milk production.

Eastalco's attorney, Benjamin Rosenberg, had contended in his closing arguments, with long statistical analyses, that milk production on at least two of the farms had improved since Eastalco opened.

During the trial, which lasted nearly four weeks, the jury heard from more than 30 witnesses and saw over 200 exhibits. Much of the testimony was from expert witnesses who reached opposing scientific conclusions. Much of the time the jury spent deliberating over the case was spent in arguing over that testimony, said a juror.

In addition, the jury looked over all of the exhibits again, including photos of cows teeth and stacks of meteorological reports. "I never saw a cow's tooth before, and I never want to see one," said the juror.

The farm families had claimed that damage to the cows' teeth was serious enough to cause feeding problems, affected the cattle's ability to produce milk, so much of the testimony revolved around the extent of that damage.

The farmers had also claimed that fluoride emissions had made their cows lame and had reduced the cattle's marketability. In addition, members of the farm families testified that emissions from the aluminum plant had sometimes left family members themselves gasping for breath and wiping tears from their eyes.

"Whether you are right or wrong, nobody can say," Judge Barrick told the jury after the verdict was presented. "The job of justice is not a mathematical certainty," he said.

At the end of the trial Rosenberg renewed a motion that the families were not entitled to claim damages for harm to their cattle. If Barrick were to rule in favor of the motion, it would nullify yesterday's verdict. Barrick said he would rule at an unspecified date in the future.