3. Advanced Secondary Treatment

Secondary treatment is the heart of the wastewater treatment process. Secondary Treatment at the Norwalk WPCF is carried out in aeration tanks, which use helpful bugs within the wastewater (known as “activated sludge”) to breakdown contaminants and biologically remove nutrients (known as a “BNR” process) in the wastewater. Air is supplied is selected zones of the aeration tanks whereas other zones are not aerated to facilitate the growth of different bugs which remove different contaminants.

Aeration Tanks