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Expanding our Derek R. Guthrie Water Quality Treatment Center


As part of the Interim Sanitary Sewer Discharge Plan, MSD specified projects that will significantly reduce unauthorized discharges—or sanitary sewer overflows—in four areas of the sanitary sewer collection system: Beechwood Village, the Hikes Point area, the Highgate Springs Pump Station and the Southeastern Diversion Structure. Implementation of these identified projects will cause significant, 
additional wet weather flow to be conveyed to the Derek R. Guthrie Water Quality Treatment Center (WQTC). The design capacity of the existing Guthrie WQTC is 30 million gallons per day (MGD), with a peak treatment capacity of 100 MGD. Based on flow projections and sewer modeling, the Guthrie WQTC will experience peak wet weather flows of more than 300 MGD. MSD created three major projects for designing and building a new wet weather treatment facility because the existing WQTC does not have the necessary treatment capacity for accepting the projected peaks.

The first of the three projects includes a new influent screening facility to satisfy the 300 MGD peak demand; a new 200 MGD influent pumping station; a new short-term detention basin, with a capacity of 427,000 gallons; and the conversion of the existing influent pumping station to a new wet weather pumping station, which will go into service as influent flows reach 200 MGD. Whittenberg Construction Company is currently under contract for building this phase.

The second project provides for the construction of the wet weather treatment facility, starting with an expanded grit-removal facility; a new aeration basin; six new secondary clarifiers; and a new chlorine contact basin, along with a new electrical high yard. Dugan & Meyers Construction Company is under contract for this part of the facility improvements.

The third project is the 19.7-million-gallon equalization basin, which will serve as a long-term-storage basin for the peak wet weather flows. As the influent flows drop, this stored wastewater will be returned to the head of the plant for full treatment. The contract for building this basin has not been awarded so far. The required operational date for all three projects is December 31, 2011.