AWWA ACE62955

The City of Calgary's Bearspaw Water Treatment Plant is presently being upgraded toincrease capacity from 420 million liters per day (ML/d) to 550 ML/d, and to enable it tomeet increasingly stringent treated water quality and environmental standards. One ofthe major components of this upgrade is a new Residuals Treatment Facility (RTF) thatwill protect the environment by recycling all the major process waste streams, rather thandischarging them to the Bow River. A major benefit of this initiative is that it will allowthe City to optimize use of their existing surface water allocation from the Bow RiverBasin.The new 54 ML/d Bearspaw Residuals Treatment Facility (RTF) manages pretreatmentclarifier waste, filter backwash waste, filter-to-waste, and process overflows. Theresiduals treatment process includes flow equalization, thickening, and dewatering. Filterbackwash waste and clarifier waste sludge are flow equalized in the equalization tanks,and gravity fed to clarifier thickeners. Clarified effluent from the thickeners will berecycled to the head of a new ballasted-flocculation pretreatment process, whileunderflow sludge will be dewatered using centrifuges. The Residuals Treatment Facilityalso includes a pump station to recycle filter-to-waste flow to the head of the main plantprocess for re-processing.Due to the magnitude of the project, and a tight regulatory deadline, the City chose toemploy a Construction Manager for project implementation. This allowed the design tobe phased, and construction to start six months sooner than if a conventional design-bid-build project delivery method had been used. There were a total of sevenequipment procurement packages and three major construction tenders produced forthe project.This leading edge project will be the first of its type in Alberta, Canada. The RTF will becommissioned in 2006, and full recycling will commence in 2007 once construction ofthe new Pretreatment Facility is completed. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2006

Number of Pages:

10

File Size:

1 file , 890 KB