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(Washington, DC – October 16, 2009) – Hazen and Sawyer has been selected to perform various services for the Washington Aqueduct Division of the Baltimore District Corps of Engineers under an Indefinite Delivery Quantity (IDQ) Contract. The Washington Aqueduct is one of the largest providers of drinking water in the greater Washington, D.C. metropolitan area, serving more than one million customers in Washington, D.C., Arlington County, Virginia, and the City of Falls Church, Virginia.

The Aqueduct operates two raw water facilities – the Great Falls Intake and the Little Falls Pumping Station, which draw raw water from the Potomac River and convey it to the Dalecarlia Reservoir. This reservoir provides pre-sedimentation prior to treatment at the Dalecarlia and McMillan Water Treatment Plants (WTP). The McMillan WTP operates in conjunction with the Georgetown Reservoir, which provides sedimentation of coagulated water prior to filtration at the McMillan WTP.

Hazen and Sawyer’s first task order under the IDQ contract is the design of upgrades to the McMillan Water Treatment Plant (WTP) Pumping Station. The Pumping Station conveys raw water withdrawn from the Potomac River to the 120-million gallon per day (mgd) McMillan WTP, through the Georgetown Reservoir and the City Tunnel. The Pumping Station consists of three single-stage, mixed-flow, vertical pumps, each of which is driven by a 900-hp, 4160 volt-motor controlled by an Anvic VFD. The Washington Aqueduct is looking into replacing the Anvic drives with newer motor control devices.

At the same time, the Aqueduct is concerned that the existing pumps may be past their useful life, and is studying alternatives for their rehabilitation or replacement. The end result of this task order will be biddable design documents for the new VFDs, possibly new pumps and/or motors, and various architectural and building mechanical improvements to the station.

Since our founding in 1951, Hazen and Sawyer has focused on two things: providing safe drinking water and controlling water pollution. Our range of services encompasses the planning, design, and construction management of water and wastewater-related projects – from clean water treatment, storage, and distribution to wastewater collection and treatment.