Owner: Town of Collierville, Tennessee
Engineer: Allen and Hoshell; Knoxville, Tennessee
Contract Amount: $19.3 million
Year Completed: 2009
W. Rogers Company expanded the Northwest Wastewater Treatment Plant from 3 MGD to 6 MGD. This project consisted of the installation of a new screw pump in the existing influent pumping station and the construction of a new second stage influent pumping station.
The main process stream included the construction of a new bar screen structure with two new mechanically cleaned bar screens, one manually cleaned bar screen, and a screenings conveyor; a new grit chamber with one new vortex-type grit removal unit and a grit classifier; two new oxidation basins with three 150 hp aerators in each basin and two (2) new 100 foot diameter final clarifiers.
The sludge process included the construction of a new RAS/WAS pumping station; a new 50 foot diameter gravity thickener with aluminum dome cover; a new solids handling building with one new two meter belt filter press, belt conveyor and polymer feed system.
The expansion also included construction of a drain pumping station, chemical feed and storage facilities for sodium hydroxide, sodium bisulfate, sodium hypochlorite and ferrous chloride; modification to the existing chlorine feed system; installation of odor control for the headwork facilities and the solid handling facilities.
When bids were opened by the Owner, W. Rogers Company was second by $340,300 or 1.72%. After evaluation considering past work history, performance, and references the Owner awarded the contract to W. Rogers Company.