The state Department of Conservation and Recreation has closed pools it runs in Brighton and Stoneham that have low attendance rates and other problems. The Brighton-Allston Swimming Pool on North Beacon Street in Brighton has been closed indefinitely. Following a spate of calls and requests, officials are working to reopen the Hall Memorial Pool in Stoneham this summer, DCR spokeswoman S.J. Port said. The Allston pool is located on a narrow strip of land, isolated by the Charles River to the north and the Massachusetts Turnpike to the south. Its condition is deteriorating and could pose health and safety hazards, Port said. In the past few years, the pool has been closed frequently because of problems with the facility, including mechanical issues.