D.C. Fire Chief Theodore R. Coleman said yesterday that the department had run up about $80 million in overtime costs in the last five years and proposed cutting the number of firefighters on engine companies from five to four as one way to reduce expenses.

The extraordinary overtime costs apparently have resulted from "manning formulas" to maintain five firefighters on engines, from use of firefighters in administrative positions and from staff shortages that have occurred under the department's affirmative action plan that requires that 60 percent of all new firefighters be black.

Since a court-ordered hiring freeze was imposed last March in a four-year-old racial discrimination lawsuit, those shortages have increased to 166 vacancies, including 99 firefighters, in a force that at full strength includes 1,374 uniformed firefighters, according to Coleman's testimony.

In a marathon hearing by the D.C. Council's Judiciary Committee on the city's public safety budgets, the city's ambulance service director announced plans to beef up training, and council member Wilhelmina J. Rolark (D-Ward 8) sharply criticized a plan by Police Chief Maurice T. Turner Jr. to recruit 1,000 reserve officers.

Coleman told a council committee that new technologies and advanced firefighting techniques make five-member engine companies unnecessary, adding that such cites as Boston, Baltimore and New Orleans use only four firefighters.

But the D.C. Council rejected the same idea in 1985, and it was criticized yesterday by several members of the council Judiciary Committee, which heard the testimony during hearings on the police and fire department's proposed operating budgets for the 1989 fiscal year.

Firefighter Thomas Tippett, president of Local 36 of the International Association of Firefighters International, also testified against the plan, saying that Mayor Marion Barry's administration was using "untrue and misleading" statements to back up the request.

After his testimony, Tippett said that department overtime costs in the last five years have been closer to $50 million and blamed much of those costs on the ambulance service. Last year, for example, the department paid $10.4 million in overtime, about $2.6 million of it for the emergency ambulance service, according to District officials.

"It's true -- $80 million and it's all taxpayers' dollars," Rolark, chairman of the Judiciary Committee, said after Coleman's testimony.

"It's obviously not acceptable, but there's nothing we can do about it if {firefighters} have the right to file these lawsuits," said council member Jim Nathanson (D-Ward 3).

"The interesting thing is in the police department they haven't let these racial problems get in the way of running the department, but in the fire department it's legendary and it's costing the taxpayers a ton of money," Nathanson said.

The complex and protracted legal battle over alleged racial discrimination in the department began in 1980 when two black firefighters filed complaints with the D.C. Office of Human Rights.

Since then, the Justice Department and Local 36, which represents about 1,000 firefighters, including about 200 blacks, have also filed lawsuits in U.S. District Court.

In November, the full U.S. Court of Appeals voted to rehear two cases challenging the affirmative action plans of the D.C. police and fire departments. Separate three-judge panels have upheld the police department's plan and overturned the fire department's.

Coleman left testimony on the ambulance service to director John M. Cavenagh, who took over the beleaguered service last September.

Cavenagh told council members that that the service had increased its training on city geography from two to 40 hours for new recruits and to eight hours for ambulance workers already on staff. Several city residents have died after ambulance crews were slow to reach them.

Cavenagh also said that 16 of the city's 46 paramedic positions have been filled with emergency medical technicians, who have not received the more advanced training frequently needed to save lives. But Cavenagh said all technicians are being offered paramedic training and said he was optimistic that all paramedic positions would be filled by appropriately trained people by year's end.

Shifting their attention to the police department, council members criticized Turner for his plan to recruit -- and arm -- 1,000 unpaid volunteers for the Police Reserve Corps to help police officers battle drug-related violence.

In an exchange that drew laughter from the crowd in the hearing room, Turner said that hundreds of residents had called to volunteer since his plan was publicized this week.

"I'm glad you received the calls, Chief, but I don't want them protecting me . . . . I want you," responded Rolark, whose district encompasses much of the violence and several of the city's estimated 71 open-air drug markets.

"One thousand sounds good, but I dispute that 1,000 would come forward," Rolark told Turner, who says the city does not need to hire more full-time officers. "You have really ignored the issue of liability."

She questioned who would be responsible if volunteers were injured in the course of duty.