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Twelve cities ranked for combined sewer overflows

Ecojustice, an environmental lobby group, has ranked 12 Ontario cities and their practices for dealing with wastewater and stormwater run-off.


Ecojustice, an environmental lobby group, has ranked 12 Ontario cities and their practices for dealing with wastewater and stormwater run-off.

In the 2013 Great Lakes Sewage Report Card, London and Windsor tied for last place with a C-. Municipalities in the Greater Toronto Area ranked best, with Peel Region (Brampton, Caledon and Mississauga) scoring an A-, and York and Durham regions getting a B+.

The report found that many of Ontario’s cities have combined sewer overflow systems that combine sewage and stormwater. During heavy rainfall they release the combined overflow into local water bodies with little to no treatment. Spills are also common when treatment plants are overloaded by wet weather.

Liat Podolsky, Ecojustice staff scientist and the report’s author, said: “The Great Lakes Basin provides drinking water for millions and is an essential part of life for Ontarians. We’re urging municipalities to reduce sewage pollution and keep Ontario’s water swimmable, drinkable and fishable.”

Municipalities, ranked from last to first, were:

12. Windsor (C-)

11. London (C-)

10. Toronto (C)

9. St. Catharines (C)

8. Sudbury (C)

7. Sarnia (C+)

6. Brockville (B)

5. Midland (B)

4. Kitchener-Waterloo (B+)

3. Collingwood (B+)

2. York and Durham (B+)

1. Peel Region (A-)

On August 8 the group sent the report to city councillors and mayors of the 12 cities, asking them to prioritize sewage infrastructure investment. Ecojustice said they want want all levels of governments to fund upgrades to “antiquated sewer systems” and recommended cities should invest in green infrastructure such as green roofs, wetlands, trees and vegetation, which can capture rainfall and reduce the amount of stormwater that may overwhelm sewer systems.

They also want municipalities to report all releases of inadequately treated sewage.

The study ranked the cities based on factors such as the number of overflow events they had a year, the overflow volume as a percentage of the total flow, the bypass volume as a percentage of total flow, treatment level, and sewer use bylaws.

The report also provides an analysis of the region’s sewage treatment laws and policies. It is a follow-up to 2006’s Great Lakes Sewage Report Card, which surveyed 20 American and Canadian cities in the Great Lakes Basin. That report found that 92 billion litres of raw sewage, mixed with stormwater, were released into the Great Lakes in one year.

To read the report, click here.