The LRBSA treatment plants use the activated sludge process to provide secondary treatment. Wastewater entering the aeration tank is combined with activated sludge, a mixture of organic material and microorganisms.
The Throop plant uses liquid chlorine bleach to kill bacteria in the treated wastewater. A chlorine contact tank provides holding time the give the disinfectant time to react. The Archbald plant uses ultraviolet light to provide disinfection.