AWWA MTC61171

The Region of Peel has embarked on a major investment in its drinking water infrastructure to meet the demands of a growing service area just west of Toronto, Ontario. Water quality challenges of the source water include enhanced pathogen risk, periodic taste and odor events, rapid temperature changes. Treatment objectives were identified that exceed local regulatory requirements (Cryptosporidium inactivation, disinfection byproducts, and water stability) and respond to concerns of the public (preserve green space, reduce taste and odor, and manage endocrine disrupting compounds). Pilot testing with three membrane suppliers was completed in 2003. The impacts of pre-treating Lake Ontario with ozone and biological carbon contactors (BACC) on membrane performance (flux, cleaning frequency, etc.) were examined during a 6-month pilot study, supplemented by bench-scale testing. Prior to this study, there was minimal industry experience with the ozone + BACC + membrane process, particularly when treating Great Lakes water. The study demonstrated improvements in membrane performance as a result of the pretreatment (ozone + BACC). After a detailed pre-purchase evaluation process, Zenon Environmental of Oakville, Ontario was selected to supply the immersed membrane system. A new generation ZeeWeed- 1000 module and cassette will be showcased in the new facility. In early 2004, the Region began the detailed design of the capacity expansion of the Lakeview WTP with ozone, BAC and membranes. The project is to commence construction on early 2005. The paper discusses the unique design issues associated with integrating these processes into such a large facility, one of the world's largest at a year-round base-load capacity of 363 ML/d (95.4 MGD) at 2°C. The plant is being designed entirely in 3D. Includes table, figures.