For 25 years Frank and Wilda Malcolm's Brookville Swimming Club has been a summer institution in Alexandria, a place where neighbors would gather to cool off in a huge L-shaped pool to socialize and perhaps even to challenge each other to game of shuffleboard.

Among high school seniors, a midnight swim at the club after the prom became a rite of spring and graduation. For others, there were fashion shows, dances and beauty contest.

Although the pool was open only 100 days a year - the Malcolms worked all year for the pool. When it was open they would be there, 64 hours a week. When it was closed, they would go to conventions of pool operators to get ideas for the next season.

But this summer it may not be so.

The Malcolms have decided to retire, and unless residents from the Brook-ville-Seminary section of Alexandria can raise more than $113,000 between now and Monday the pool, off Shirley Highway will not reopen.

"We just decided that it needed new blood," Wilda Malcolm said yesterday. Her husband, who is in his 60s has been ill, she said, and her daughters have been pressuring her to stop working so hard. "I'm going to miss being there, but then, I hope to swim this simmer instead of work," she added.

For the 3,000 people who have used the private swim club in past summers, the propects of swimming in Brookville again this summer are not bright. As of yesterday the Brookville-Seminary Valley Civic Association had raised only $48,000 of the $120,000 it needs to keep the pool open, said Virginia Dolan, head of a neigborhood committee.

"There will be more than 2,000 children very interested in getting into mischief in the streets of Alexandria this summer if we don't open this pool," she said.

The neighborhood group hopes to incorporate as the Northern Virginia Swim Club and ultimately buy the complex from the Malcolm, she said. That would take $1 million, a sum that the new corporation would have to raise through sale of stock to swim club members, Dolan said.

A delay in mailing a fund-raising announcement to former members of the club has slowed the drive, Dolan said. If the goal isn't reached by Monday, she said the civic association will refund the money it was raised. Efforts to sell the pool to Alexandria and to the Northern Virginia Regional Park Authority for about $1 million have failed, spokesmen for the city and the park authority said, Mrs. Malcolm refused to say what she and her husband will do with the pool if the civic group's also fail.

Alexandria officials said the city has funds to run one large public swimming pool and has plans to lease another private pool this summer, but can afford the cost of operation the Brookville pool as well, A spokes-woman for the pool did not serve a wide enough area to meet the authority's regional requirements.

Chris Jeco, a 14-year-old on the pool's swim team, said prospects of a summer without the pool are frightening. "It's going to be boting this summer," he said.