Pumps raise incoming wastewater to a higher elevation, enabling it to flow naturally through the rest of the treatment process using gravity.

The LRBSA treatment plants utilize the activated sludge process for secondary treatment. In this process, incoming wastewater is mixed with activated sludge— a combination of organic material and microorganisms— in the aeration tank.

The Throop plant uses liquid chlorine bleach to disinfect treated wastewater, with a chlorine contact tank allowing sufficient time for the disinfectant to effectively eliminate bacteria. In contrast, the Archbald plant employs ultraviolet light for the disinfection process.

Once the treatment process is complete, the final effluent is safely discharged into the Lackawanna River.

At the Throop plant, anaerobic digesters are used to break down organic material in both primary and waste activated sludge. “Anaerobic” refers to the absence of oxygen in the treatment tank during this process.

The treated sludge, now referred to as biosolids, is passed through a belt filter press, where rollers squeeze out excess water.