Specifications include, but are not limited to: This project consists of all labor, materials, and equipment to construct pretreatment basin improvements at the Aberdeen Water Treatment Plant. Work includes modifications of influent piping, modifications of effluent piping, effluent control structure, replacement of sludge pumps, and replacement of sludge valves and piping together with related subsidiary and incidental work in accordance with the plans and specifications. Influent piping revisions include modifications to piping and valves to optionally divert backwash water to the pretreatment basin. Effluent piping revisions include construction of an effluent control structure, slide gates, piping, valve, fittings, and core drilling. Sludge piping revisions include replacement of two (2) vortex impeller sludge pumps, piping, and valves. The project includes incidental structural and electrical work to accommodate the improvements.