AWWA ACE65505

This powerpoint presentation presents a project to upgrade a large scale pretreatment process at the Bearspaw Water Treatment Plant in the City of Calgary Water Resources, Calgary, Saskatchewan, Canada. Pretreatment facility objectives included: low clarified water turbidity; protozoan sized particle reduction; organic carbon reduction; disinfection byproduct (DBP) precursor reduction; and, taste and odor reduction. Current upgrade program drivers included: Water Quality (Regulatory and Voluntary); Water Quantity (Demand vs. Capacity); Safety Considerations; Plant Reliability; and, Environmental. Technology pre-screening criteria is listed, along with process evaluation for: plate settlers; Dissolved Air Flotation (DAF); and, Actiflo® ballasted flocculation. The process selection summary included: Actiflo® was selected - best treated water quality for all raw water quality conditions; Actiflo® and DAF were found to have similar overall project costs; DAF process would be severely limited during the high turbidity spring run-off events; and, plate settlers had highest life-cycle costs and the least improvement in water quality. Actiflo® design parameters are presented, along with an illustration of the Actiflo® process, a process flow diagram, pretreatment facility plan view, and pictures of the construction site.