Challenges with Maintaining Potable Water Quality—Designing Large Diameter Water Mains for Demands of Today and Tomorrow

The Region of Halton is experiencing rapid development and growth. Under the Sustainable Halton Water and Wastewater Master Plan, the Trafalgar and Derry Road Feedermains and 30 mL Zone 4 Reservoir Project was developed to provide Halton Region with sustainable growth and servicing strategies to meet the needs of the growing population. The growth requirements in North Halton have identified the need for a future maximum day flow of nearly 9 mL per day with a peak hourly flow over 16 mL per day. This increased future water demands combined with the limitations of sustainable groundwater supply has led to the identification of the need for greater integration of the region-wide water systems. This paper will discuss the approach taken in the design of over 18 km of large diameter feeder mains to minimize operational and maintenance issues, reduce overall capital costs, while providing maximum operational flexibility to maintain water quality objectives under both short-term and long-term project water demands.