At the North Saskatchewan Watershed Alliance AGM, June 20, 2012, the Drainage Services group of the City of Edmonton described the progress made in rehabilitating combined storm and wastewater sewers and mitigating the overflow from exceptional runoff events. Total Suspended Solids (TSS) is the target contaminant since it is a proxy for other key pollutants. The City of Edmonton has developed eleven wetlands, underground sediment treatments, and is promoting low impact developments to mimic natural hydrology.
Drainage Services also has a combined sewer overflow program that works to reduce the untreated flow from old infrastructure. In-line storage using control gates in the sewer system stores storm run-off and directs it to the wastewater treatment plant once peak flows have reduced. The Rat Creek tunnel project redirects overflow from downtown Edmonton, under the river to the Goldbar wastewater treatment plant which also has had its capacity upgraded. The progress to date and future plans to reduce nutrients, sediment and other pollutants is covered.
Presenters were Dr. Fayi, Zhou, General Supervisor of Environmental Planning and Drainage Planning, Drainage Services Branch, City of Edmonton and Mohammad Tariq, senior engineer in charge of combined sewer overflows management in the Drainage Services Branch, City of Edmonton.
