finding outdoor year round pools in suburban maryland

Hello, I just discovered this website while searching for outdoor year-round pools in suburban Maryland (just north of D.C.). I live in Frederick, MD, and my pool covers over with a bubble in winter--the bubble just went up. BUMMER! Does ANYONE know of an outdoor year-round pool close to or in Frederick? I do know of the Bethesda and Silver Spring YMCA, but they are a little too far to drive, and there is a long waiting list at Bethesda Y. Many thanks!! aandw