Interim Milestone Work: replacement of existing primary clarifier equipment, including motors/drives, axles, and other equipment for eight (8) primary clarifier sludge collectors, eight (8) lateral sludge collectors, and eight (8) primary clarifier scum skimmers, associated electrical work, installing VFDs for clarifier equipment, replacing motor control centers for Primary Sludge Pump Buildings Number 1 and 2 and SCADA integration. Substantial Completion Work: upgrading various electrical equipment, including influent relief pump station medium voltage switchgear, influent pump station medium voltage switchgear, wet weather medium voltage switchgear, operations and control building medium voltage switchgear, and associated work.