The Clayton County Water Authority faces a big daily challenge. It serves one of Georgia’s most densely populated counties, but unfortunately sits atop a subcontinental divide, leaving it with limited natural water resources.
Yet during a severe drought in 2007-08, the five reservoirs the utility — based in Morrow, just south of Atlanta — relies on for drinking water never fell below 77% capacity. By comparison, the water level in nearby Lake Lanier, Atlanta’s primary source, hit record lows.
The utility sustained its drinking-water supply through an innovative system of constructed wetlands that filters treated effluent, discharged from two wastewater treatment facilities. The gravity-fed
