The former general manager of an oil recycling firm was fined and sentenced to a six-month work-release jail term today for lying to a grand jury and attempting to cover up his company's illegal disposal of chemical wastes, including 12,000 gallons of PCB-laden oil.

Frank P. Young Sr., 43, former general manager of American Recovery Co.'s plant at Sparrows Point on the Baltimore Harbor, is the first executive of a chemical company to be sentenced to jail in the state's aggressive three-year-old campaign to bring criminal cases against violators of state environmental laws. He was convicted by a jury in September.

American Recovery pleaded guilty in February to dumping thousands of gallons of chemical wastes into the Baltimore Harbor and to illegally selling 12,000 gallons of PCB-tainted oil to unsuspecting buyers. Young and a codefendant were accused of directing the illegal disposal.

Yesterday, Baltimore Circuit Court Judge Joseph F. Murphy Sr. fined Young $2,000 and sentenced him to a detention center work-release program, as well as five years' probation for violating state environmental laws.

According to prosecutor Jane Barrett, Young, who was fired by American Recovery in April, has had a $48,000-a-year consulting agreement with the company since then. Young's attorney, Paul Mark Sandler, confirmed the existence of a consulting agreement but said he did not know how long it would continue.

Barrett had urged Murphy to impose a harsh sentence on Young, saying it would serve as a warning to other firms that handle chemical wastes. She recommended a three-year jail term and a $50,000 fine.

"I can't stress enough the importance of sending out as a message that there is some personal liability, some personal responsibility to obey the law," she told the court. "We have to stop this . . . before we have more waste sites."

But Murphy, who called Young "a fine family man," said jail time for Young's violations of environmental laws would be inappropriate.

Young and company and plant manager John Driscoll, 35, were accused of illegally storing and disposing of hazardous wastes on 13 dates between July 1, 1982, and Feb. 21, 1984, and of lying to the grand jury.

In December, Driscoll pleaded guilty to conspiracy and to dumping hazardous wastes. Murphy has since sentenced him to probation before judgment.

Young could have been sentenced to maximum penalties of 23 years in prison and $400,000 in fines.

American Recovery plans to close its Sparrows Point plant at the end of the month. Deke Abbott, chairman of Union Corp. of Verona, Pa., American Recovery's parent company, said the shutdown is a result of the company's inability to attract customers since the state's prosecution.

An American Recovery plant at Baltimore's Curtis Bay shut down early this year when it was faced with state revocation of its hazardous waste permit.

Maryland's environmental crime-fighting program, begun in 1982 by Attorney General Stephen H. Sachs, is, along with those in New Jersey, New York and California, among the most aggressive in the country. So far, 13 persons in Maryland have been convicted of environmental crimes ranging from mixing oil contaminated with PCBs (polychlorinated biphynels) with clean oil for resale as untainted fuel, to polluting the air by burning hazardous and infectious waste in unlicensed furnaces.

Two of those convicted in addition to Young have received jail sentences, while the others have paid fines, been put on probation or made to perform community service, according to Barrett. Twenty-three companies have been convicted of pollution crimes in the state, Barrett said, while one company in Garrett County was acquitted. Six similar cases are pending against individuals, she said.

Nationally, the U.S. Department of Justice Environmental Crimes Unit program, begun in 1983, has won convictions against 77 individuals in more than 100 cases from New Hampshire to New Mexico. Twelve company officials have received jail sentences while the remaining 65 have paid "stiff fines," according to Judson Starr, chief prosecutor of the federal program.