Per Crossroad News, in response to the heat wave and through June 22, DeKalb County "is temporarily waiving admission fees at all pools until 6 p.m. on Monday with the exception of the Browns Mill Aquatic Facility."
In general, Medlock pool is "Open Wednesday-Saturday noon-6 p.m. (closed Tuesdays)" and open Sundays 1-6pm.
For locations and details, go to http://crossroadsnews.com/news/2015/jun/19/cool-free-swims-county-pools/