Twenty percent of the time that the Prince George's County fire department responded to fires last year, it didn't have enough firefighters to go along, County Executive Parris Glendening said yesterday. Drawing on a task force report recently completed in the area of public safety, Glendening also said that the part of the county south of Clinton is largely unserved by mobile intensive care ambulences.

The county has four such ambulances, he said, but 10 are needed. In addition, the county needs more police.

The 25-member public safety task force outlined staff and equipment deficiencies in the police and fire departments that it said have led to an erosion of services in the growing county. Glendening said he is not optimistic about finding funds in the budget to make significant improvements.

Glendening's public safety liaison, Michael Knapp, agreed with the findings of the task force, saying, "We simply don't have enough officers to cover the beats we have." Understaffing, in addition to a growing number of calls for service, has increased police emergency response time from 4.5 minutes in 1978 to 6 minutes last year, Knapp said.

The fire department has asked for 92 additional personnel and the police department has asked for 30 more police officers. However, Glendening said yesterday that if the state does not increase the county's budget, as many as 1,000 county employes may have to be let go next year.

As for the leadership of those two departments, Glendening pointed out that he has reappointed Fire Chief James Estepp, but said that he and Police Chief John McHale are still discussing "options" and he has not yet decided is he will permanently reappoint the chief, who was chosen by former county executive Larry Hogan.

Replacing worn fire equipment and police cars and the purchase of at least one $300,000 mobile ICU unit, are top priorities, Glendening said. Other components of the 14-point public safety plan include finding new sources of revenue to support the fire and rescue service, encouraging business owners to get involved in crime prevention programs, increasing efforts to protect the elderly and reducing the number of drunk drivers.