Specifications include, but are not limited to: Process modifications in the aeration tanks by installing the following: Internal mixed liquor recycle pumps in Zone 1D and 2D along with modifications to the aeration diffuser grids in these zones. Mixed liquor recycle piping, valves, and gates from Zone 1D to Zone 1A3 and 1A4. Mixed liquor recycle piping, valves, and gates from Zone 2D to Zone 2A3 and 2A4. Installation of two new baffle walls to form Zone 1A5 and 2A5 along with aeration diffuser grid modifications and installation of new gates. Installation of two new floating mixers and oxidation reduction potential probes in Zone 1A5 and 2A5. New aeration diffuser grids in Zone 1B, 2B, 1C, and 2C. Incorporation of automatic dissolved oxygen control for Zones 1B, 1C, 1D, 2B, 2C, and 2D by installing dissolved oxygen probes, electrically actuated control valves, airflow meters in these zones.