Many Alexandria churchgoers can expect to hear a lecture on swimming pools from the pulpit this Sunday.

City Council member Nelson Greene, Sr. said yesterday he met with black ministers this week and persuaded them to join an effort to quell the vandalism and rowdyism at the city's swimming pools that make this summer one of the most unruly in recent memory.

At the same time, City Manager Douglas Harman has ordered police to step up patrols of the pools and is considering hiring nighttime security guards to prevent break-ins.

Because of the repeated vandalism and occasional violence at several pools, some council members have asked Harman to re-examine newly instituted admission fees. Some warned that pools may be closed if disruptions continue.

"If we can't ensure public safety we'll have no other recourse but close the pools," said council member Donald C. Casey.

The lastest action follows the resignation of one pool manager, and the transfer of several others because of unabated clashes with rowdy swimmers. Last weekend more than 50 swimmers stormed the gates at one pool and broke in for a prehours dip.

Michael Tapscott, who resigned as manager and head lifeguard of the Cameron Street pool last week because "things got to be too much," laid most of the blame for trouble on the lifeguards, however.

The most severe incidents, including the beating of a cashier, have occurred in predominantly black, low-income areas. The majority of lifeguards there are white and Tapscott said have aggravated tensions because they don't know how to deal with pool patrons. "They don't know how to berate them and leave them with a shred of dignity," Tapscott said.

Recreation department officials said they have not been able to find enough qualified black lifeguards. "If I had them, " said sports director Joseph Vinci. "I would certainly put them there."

City Manager Harman said he is also considering "added pay incentives" for recreation personnel willing to work at pools with the most severe incidents of physical violence and verbal abuse.