Cobb County-Marietta Water Authority replaced 24 1,500-pound tanks of chlorine gas two years ago with an electrolytic bleach system at its James E. Quarles Water Trement Plant. A similar conversion is under way as part of the $103 million renovation of the authority’s other water purification facility, the Hugh A. Wyckoff Water Treatment Plant in Acworth.
Chlorine gas, which is used to disinfect water, is a terrorist risk, according to the Department of Homeland Security, because an attack on the plants could cause the release of the gas that can cause severe health problem when people are exposed to the chemical. Water treatment plants that used to be in rural areas are now in the middle of suburban developments intensifying the risk.
Other plants across metro Atlanta have converted to new systems that include treating the water with ozone or UV. These systems can serve as the primary drinking water disinfecting system with bleach used as the secondary disinfectant.