Implementing dozens of recommendations to clean up sewage contamination of Hamilton’s Chedoke Creek could cost the Ontario city more than $150 million over 14 years, a new report suggests.
The latest report (pg. 114) from GM Blueplan Engineering offers options for studies, projects, programs and maintenance to the City of Hamilton’s general issues committee sitting on July 5th, as they determine how best to remediate the creek. The problem began due to the incorrect operation of a combined sewage overflow (CSO) tank valve and the malfunction of a second gate valve without detection. Ultimately, a bypass gate that was left open, leaked approximately 24 billion litres of combined sewage into the creek over four years.
Ontario officials charged the City of Hamilton last December for permitting the raw sewage to be released. The two charges for the contamination came under the authority of the Environmental Protection Act and the Ontario Water Resources Act.
In response to cleanup requirements, City of Hamilton officials warned that it could take nearly a year beyond Ontario’s fall deadline before it was able to complete the dredging of the creek.
Subscribe to our Newsletter!
The latest environmental engineering news direct to your inbox. You can unsubscribe at any time.
A separate consultant’s report in spring 2019 advised City of Hamilton officials not to remediate the areas in question. There was a recommendation of “no action.”
In the latest report, several priority actions are suggested to begin addressing the contamination. Already underway is the recommendation to twin the Highway 403 trunk sewer running from the Royal CSO tank to the Main-King CSO tank, east of Highway 403.
The project consists of four phases with phase one under detailed design, phase two already constructed, and phases three and four requiring future design and construction. The objective of the trunk sewer is to provide additional sanitary sewer capacity for the catchment upstream of the Main-King CSO tank and provide an outlet for the Aberdeen CSO to significantly reduce combined sewer overflows, the report stated.
Also recommended in the report is reducing overflow by rehabilitating the existing Highway 403 culvert to address existing landfill leachate flow entering the culvert and discharging directly to the Lower Chedoke Creek.
An additional priority for the committee to consider is to better manage runoff from the city-owned Chedoke Golf Course, which can involve pesticides and fertilizers. Better stormwater management practice, the report stated, would improve the quality of the runoff from the golf course operations and improve the creek’s water quality.
The report also recommends better stormwater management measures for Highway 403 to increase the creek’s water quality. Researchers identified the need to address contaminants such as oil, grease, pavement deterioration, tire and brake pad wear, vehicle emissions, and spills that are present along the highway.
A series of new studies will also be considered.