Shortly after Toronto's historic early July rainfall, Mark Mattson, director of environmental charity
Lake Ontario Waterkeeper, spoke with the
Toronto Star about the storm’s anticipated damage. According to Mattson’s estimations, the storm resulted in more than a billion litters of untreated sewage flowing directly into Toronto's streets and water systems.
While City officials believe those numbers are exaggerated, there’s no question that Toronto’s sewage infrastructure is in desperate need of an upgrade. A new comprehensive report by Canadian environmental charity Ecojustice suggests that Ontario municipalities annually dump billions of liters of untreated or partially treated sewage directly into the Great Lakes. Without serious policy intervention and
infrastructure upgrades, the report’s authors conclude, the problem will only get worse.
The 2013 Great Lakes Sewage Report Card—a follow-up to the organization's 2006 report card—ranks 12 Ontario municipalities based on their sewage management system. Toronto ranked 10th, the York & Durham region ranked 2nd.
"The Great Lakes Basin is one of the most important freshwater ecosystems on the planet," says Liat Podolsky, report author and Ecojustice staff scientist. "Sewage pollution in the Great Lakes impacts the quality of the water, as well as the biodiversity of the Great Lakes and all the species that live there. It affects our recreational enjoyment of the water and beaches, and increases the costs to treat drinking water."
The major contributor to lake pollution, according to the new report, is untreated municipal waste water that flows directly into waterways. This can happen either through a plant bypasses—where an overwhelmed wastewater treatment plant releases untreated or partially treated sewage directly into a local body of water—or, as is the main problem in Toronto, through a process known as combined sewer overflows (CSOs).
Like many municipalities in Ontario, Toronto uses both combined and separate sewer systems. In a combined sewer system both sanitary sewage and stormwater are carried in the same pipe. When the volume of water flow exceeds capacity, water that would normally be transported to a treatment centre is released directly into local bodies of water. According to the Ecojustice report, 25 per cent of Toronto is serviced by combined sewers.
Yet, while Toronto ranked in the bottom three of the 12 municipalities studied, the Ecojustice report does point to a number of Toronto initiatives underway that, if fully implemented, will likely improve the city's future sewage treatment score. Among these initiatives are plans to address CSOs and stormwater discharges from 50 combined sewer outfalls along lower the Don River, Taylor Massey Creek and the Inner Harbour.
"Toronto is making good investments to upgrade its aging infrastructure, and also makes extensive use of green infrastructure to absorb and manage stormwater at the source and prevent it from going into the system for treatment," says Podolsky.
But there's still a long way to go.
A good first step, says Podolsky, is accurate reporting. Toronto currently has no method for publicly reporting bypasses and combined
sewer overflow events. The result is that residents don’t know when these overflows are occurring nor which areas have been impacted.
"Toronto needs to continue working towards and prioritizing the upgrading of antiquated infrastructure, such as combined sewers, to
reduce the frequency and volume of combined sewer overflows that it experiences each year," adds Podolsky. "Given the probability that we will continue to see more frequent intense storm events, such as the flood we had in July, we also need to find ways to control and manage all the excess stormwater at the source that will overwhelm the system during these events.
"The Great Lake Basin provides drinking water for millions and is an essential part of life for Ontarians," Podolsky continues. "We're urging municipalities to reduce sewage pollution and keep Ontario's water swimmable, drinkable, and fishable."