Data on sewage overflows now available on public data portal!

Imagine watching the water rush over Niagara Falls for a full 24-hours. Now imagine it wasn’t water at all…imagine it was raw sewage. That is how much sewage was dumped into Canadian waterways in 2017. That’s 270 million cubic metres.

Where does this sewage come from? Either areas that offer no treatment, so it just flows (if that’s the word) untreated into our water bodies, or from combined sewer overflows – sewer systems that combine both wastewater and stormwater, and when they hit their maximum levels, they overflow.   

We all intuitively understand that sewage is yucky. Nobody is excited to swim, paddle or fish in sewage-affected waters. And, as you can imagine, untreated sewage wreaks havoc on water quality, and can include a who’s who list of contaminants including all kinds of bacteria (like E.Coli), viruses (like Giardia) and parasites which can make people and animals sick—and may even be lethal. It is also very high in phosphorus and nitrogen, contributing to nutrient pollution that can drive toxic algal blooms.

Though this news is not great for our waters, it is a win that Statistics Canada is now publishing the information on a new public access portal. The data 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 Combine Sewer Overflows alone, Quebec leads the nation, followed by British Columbia, Nova Scotia and Ontario.  

But thanks to the work of Our Living Waters Network members, there are solutions to our combined sewer overflow problems. Check out the toolkit "Tackling Combined Sewer Overflows" developed by Ottawa Riverkeeper. 

On the positive side, let’s look at what a few communities are doing to solve the combine sewer overflow problem:

  • The City of Ottawa is currently building a Combined Sewage Storage Tunnel, a storage facility designed to hold up to 43 million litres of sewage and stormwater. The tunnel is intended to create more capacity for combined sewers, which would take pressure off existing infrastructure in times of heavy precipitation and therefore decrease instances of overflow events. Notwithstanding this project, it would not have prevented at least nine CSO events in 2017, which generated more volume than the tunnel can hold. The tunnel, which will be operational in 2020, should stop CSOs in all but extreme weather events. 
  • Although the scope of the CSOs is particularly daunting in Vancouver, there is work underway to address the issue. For example, Metro Vancouver (the regional government consisting of 22 member municipalities) is slowly separating stormwater sewers from wastewater sewers, with the goal to eliminate all CSOs by the year 2050. They are prioritizing sewers that are the worst offenders. They have also required all 22 member municipalities to adopt Integrated Stormwater Management Plans, which include actions like integrating green infrastructure into land-use planning in order to minimize runoff that makes its way to sewer systems in the first place.  The City of Vancouver is also in the process of developing a Rain City Strategy, with the goal of minimizing runoff by capturing and cleaning 90% of rainwater that falls in the city.   

While solutions need to be enacted in these specific places, it is ultimately a national challenge. One that OLW Network members are committed to turn the curve on (ending Canada’s sewage pollution problem is a priority for the OLW Network). 

If you are driving solutions to Canada’s sewage pollution problem or are looking to collaborate with those who are, please reach out so we can connect you with like-minded organizations. 



Our Living Waters Impact Measure for Combined Sewer Overflows

Statistics Canada Combined Sewer Overflow Data

Statistics Canada Municipal Wastewater Systems Overview

Lindsay Telfer
About Lindsay Telfer
Mom, organizer, capacity builder, outdoor enthusiast, justice advocate. Thoughts posted are my own :).
Data on sewage overflows now available on public data portal!
Data on sewage overflows now available on public data portal!
Imagine a Canada where all waters are in good health: