1. Modifying the headworks, including but not limited to replacing and installing mechanical screens with wash presses; adding a spray system including headers, nozzles, and connection to the plant water source; replacing and installing the plant water booster pump skid; replacing and installing the hydraulically induced grit-removal system trays; modifying and adding to the concrete; and modifying and adding to the piping, valves, fittings, and appurtenances, specifically including the odor-control piping connection indicated in the Contract Documents. 2. Modifying the internal recycle piping, valves, fittings, and appurtenances. 3. Modifying the oxidation ditch walls, stairs, and walkway. 4. Constructing denitrification structures, including but not limited to secondary anoxic basins, reaeration basins, a clarifier splitter box, submersible mixers, positive displacement blowers, fine-bubble diffusers, slide gates, weir plates, davit cranes, sample pumps, analyzers, chemical storage and feed, drainage, piping, valves, fittings, and appurtenances.
