As our global and national population continues to grow, there are events that naturally follow. For example, in 1950 the population of Toronto was about 1,068,305. By 2021, the population had risen to 6,254,571. That growth means more homes, more good and services, more roads, more parking lots and rooftops. Where rainwater used to fall onto undeveloped areas, it is now collected, channeled, and in too many cases, combined with sanitary sewage. During times of heavy rain, something we saw plenty of in the summer of 2021, this creates a public health issue as this untreated or limited treated water ends up in lakes, rivers, and streams. We’ve blogged about this in the past.
A combined sewer overflow system (CSO) collects rainwater runoff, domestic sewage, and industrial wastewater into one pipe. Under normal conditions, it transports all of the wastewater it collects to a sewage treatment plant for treatment, then discharges to a water body. However, during heavy rain events, the sewage treatment plant is unable to process all the water and can lead to the sewage/rain water receiving limited or no treatment prior to discharge into the water body.
Provinces Discharging Sewage
According to Our Living Waters, “The data (from Statistics Canada) shows that BC is leading the nation in total sewage released into waterways (both CSOs and untreated discharges), followed by Quebec, Nova Scotia and Newfoundland. Looking at Combined Sewer Overflows alone, Quebec leads the nation, followed by British Columbia, Nova Scotia and Ontario.”
Unreported Discharges
Our Living Waters goes on to report, “In 2015, a reported 1,516 combined sewer overflow locations existed across 130 municipal systems, and according to Statistics Canada that year, 168,800,000 cubic metres of untreated sewage was released from CSOs into the water. Please note that the actual volume of untreated sewage released into Canadian waters is likely higher than reported. Across Canada, 268 municipal systems are required to report CSO discharges, however many do not report accurate data concerning the volume and rate of sewage releases to Environment Canada. For example: in 2015, only 36 of 168 municipal systems in the province of Quebec filed completed combined sewer overflow reports; some municipal systems filed a record of overflow events but did not report any volumes; the City of Toronto did not report overflow events or volumes for January, February, March, November, or December.”
These months of unreported discharge may be related to cold temperatures and lack of precipitation.
Too many communities still have CSOs and outdated sewer systems (Image by Frauke Feind from Pixabay).
IJC Report on Great Lakes Cities
In a 2017 report generated for the International Joint Commission regarding Great Lakes Water Quality, they state, “20 Great Lakes cities in Canada and the US released a combined total of 92 billion gallons of untreated sewage and stormwater to the Great Lakes, mostly via CSOs. That’s roughly equal to 147,000 Olympic size swimming pools. Between Canada and the US, there are about 291 cities in the Great Lakes basin with antiquated sewer systems, which release CSOs, 109 in Canada and 182 in the United States.”
Effects of Discharges
This decades-long problem can make beaches “unswimable” due to E. Coli contamination and can contribute a variety of industrial contaminants that avoid treatment during the CSO event. Further, we know these events can contribute to the ongoing global problem of eutrophication as nitrates and phosphorus are discharged.
Recent Discharge in the City of Hamilton
The problem of sewage overflow continues to this day. The City of Hamilton recently had an event that resulted in approximately 353 million litres of waste water entering Hamilton Harbour.
According to Global News, “The city of Hamilton says heavy rainfall and an equipment failure were the cause of about 353 million litres of partially or untreated sewage being dumped into Hamilton Harbour overnight on Monday” (October 4th).
According to the same report, city staff estimates that for roughly six hours, there was a full plant bypass discharging 48 million litres of completely untreated sewage.
The event lead to Pier 4 at Hamilton Harbour being closed due to blue-green algae.
While there are many critical environmental issues that require our immediate attention, protecting our water for consumption, for fishing, and for other recreational purposes should be a top priority.
Feel free to connect with me on LinkedIn. If you have an immediate need or concern, you can reach me at 519-948-7300 Ext. 114 or by email at cpare@dragun.com.
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