Understanding CSOs
“Where does my poop go after I …go?”
We know this question has crossed your mind more than once. It’s a good one to ask because your after-coffee morning ritual might just be making an appearance in places you don’t want to see -or smell- it.
We want to better help you understand sewage issues, to better help you get into the water more often, where you know it's okay to do so. This is what we call water literacy. It's one of the initial steps in helping you become a community advocate in supporting swimmable, drinkable, fishable water for everyone.
So let’s dive into the world of sewage! More specifically, combined sewer overflows (CSOs)
There are three types of sewer systems: wastewater, stormwater and combined. Combined sewer systems collect domestic and industrial wastewater, as well as stormwater together in one pipe. The purpose of combined sewer systems is to transport this combination of sewage and stormwater to a wastewater treatment plant for processing.
Why Do Combined Sewer Overflows Happen?
A CSO occurs when the combination of sewage and stormwater exceeds the capacity of the sewer system and is released directly into nearby lakes, streams, rivers, or other natural bodies of water.
Outdated infrastructure with an increasing population and more intense weather due to the climate crisis is only making these CSOs more common.
Another factor that can amplify CSOs is the lack of green infrastructure. Green infrastructure can help to soak up the excess stormwater and take some of the burden off the water treatment plants.
“If a bathtub fills up, you’ve got the little relief thing where it stops it from spilling over, right? So that’s if it’s raining normally and not too heavy, you get a little bit that drains over the side, the tub holds most of it. The challenge that we’ve been seeing lately is, as we get heavy, heavy rainfall, it’s essentially like using a fire hose to fill the bathtub.”
- Lou Di Gironimo - General Manager of Toronto Water
Let’s take a step back, back to the beginning
The first sewer systems in North America were built in the late 1850s in Chicago and Brooklyn. Most urban cities that were developing around this time had combined sewers as their primary system. Even today, you can come across many CSOs in Toronto's old core, Metro Vancouver, Hamilton, Kingston and most urban cities in North America still have combined sewers.
Have you ever heard the saying “out of sight, out of mind”? that’s a perfect way to describe one of the main reasons these issues aren’t being addressed. Sewer systems are hidden below the surface, sometimes you will see unnatural discharges and pollution entering the lakes and sometimes if you’re walking downtown after a rainy day you can smell sewage and see floatables. But most of the time the outflows are invisible..
“One of the reasons that it has been so difficult to get traction around most water issues in our North American cities is that the infrastructure has been allowed to become completely invisible. Everything is in a black box, and as a result we imagine this infrastructure as a ubiquitous network that just works.” - Vanishing Point
The Vanishing Point is a website & resource that emerged from a decade of underground research and photographic practice by Michael Cook. See sewers in: Toronto - Hamilton - other places
Niagara Falls? more like Sewage Falls
Picture this, Niagara Falls in the middle of fall with all the leaves changing colours, folks snapping some pictures of one of the wonders of the world… but wait, what’s that smell? it’s not pumpkin spice. Is that sewage in the falls?!
Now imagine, Niagara Falls flowing untreated sewage for 3.7 days.
From 2013 to 2017, 890 million cubic metres of untreated sewage and wastewater was released from combined sewer overflows (CSOs) into 844 different waterbodies across Canada.
“When I see grease and fat, condoms, tampons, tampon applicators, maxi pads, wipes, and other waste floating in the lake, it's upsetting. I love the feeling of jumping in and getting swallowed up by Lake Ontario’s sometimes shockingly cold water. I swim, paddle, boat, fish, and hopefully someday soon, I’ll surf and dive in this Great Lake. Because I feel connected to it, I inherently feel the responsibility for caring for this lake as much as many of you do.”
- Ruby Pajares, Torontonian, recreational water user
Video: Isabel Fleisher - Manger, Lake Ontario Waterkeeper exploring a breakwall around Ontario Place where dozens of condoms, tampons and sewage were found entering Lake Ontario.
Toronto CSO stats:
There are 94 total outfalls that could potentially contain combined sewer overflows.
The combined sewer system runs as far north as St. Clair and Warden, east to Scarborough Crescent Park, south to the waterfront, and west to where the Humber river meets Lawrence Ave. Map of total area can be found on page 9 of this City of Toronto document.
CSO spills occur throughout the city at least a few times per week between April and October, and as many as multiple CSO events per day during heavy rainfall. November-March rarely see any combined sewer events, if at all.
BREAKDOWN:
Aquatic Life
Just like we wouldn’t want to swim in sewage water, neither do any of the aquatic life. As we begin to improve our accessibility to swimmable drinkable fishable water we need to keep in mind all the ecosystems and lives that are involved in this process. That includes all water life.
Lakes and rivers not only provide us with drinking water, they are also homes to a wide range of biodiversity. When a combined sewer overflow happens, the untreated sewage and urban pollutants that enter the water cause immediate and long-term damage to the ecosystem such as mass death of species, algae blooms and low oxygen in the water. Making it not healthy to live in or swim in. Sewage impacts fish survival, cause shellfish bed closures, contaminate water supplies, and destroys aquatic life. They also increase water temperature and impact water clarity making it cloudy. CSOs threaten the health of our watersheds by introducing excess nutrients and decreasing oxygen levels. Sewage contains phosphorus, which in high enough amounts can lead to algal blooms. The organic material added to the water increases the need for decomposition, a process that uses up oxygen. Decomposition decreases levels of dissolved oxygen in the water threatening wildlife like fish and benthic invertebrates that need dissolved oxygen to survive.
Public Health
Combined sewer overflows can be a big concern for human health. Sewage-polluted waters contain pathogens, heavy metals, pharmaceuticals, and chemicals that can lead to illness and infection. Exposure to contaminated water from a CSO poses health risks to humans. After a CSO, bacteria such as E.coli, viruses, and parasites can be found at elevated levels in the water, leading to diseases and infections. Gastroenteritis, rashes, and ear, nose, and throat infections are the most common illnesses associated with contaminated water. More severe health outcomes include typhoid, cholera, dysentery, infectious hepatitis, and severe gastroenteritis.
ACTIONS:
Educating yourself is the first step. Action is what follows, and that’s how we can make an impact in our communities. There are many things we can do as individuals to keep these water systems healthy, not only for ourselves but for our communities as well.
Individual Actions
Be aware that every time you flush your toilet or turn on your tap that water is part of a larger ecosystem
Avoid access water use during a heavy storm. Wait until after the storm to do laundry or have a bath
Use a rain barrel to collect rainwater from your downspouts. You can use that water for your grass and plants
Wash your car at a car wash facility where the water is often recycled before being released into the sewers
If you notice a CSO or problem with storm drains or pollutants entering the water, contact your city officals.
Every small action can create a ripple effect for the change we need.
Swim Guide
The Swim Guide is a free app and website that brings the latest water quality results to the public in a way that is clear and easy to share. Another feature of Swim Guide is the ability to report pollution to alert that beach’s Waterkeeper of the incident.
Open Government Portal:
In 2018, Swim Drink Fish submitted a formal request to Environment and Climate Change Canada (ECCC) to release data in relation to sewage pollution in Canada on the Open Government Portal. The release of this data would provide free, on-demand access to machine readable data files for sewage pollution nationwide. On November 25th, 2019 ECCC released this data that was gathered under Wastewater Systems Effluent Regulations (WSER). This release sets an important precedent publishing other environmental regulatory data for public consumption.
Initiatives & Actions by Cities:
Toronto:
If you’re in the core of the city, especially in the older parts and if you see, smell, or maybe even taste something suspicious in the water, call 311 . You can find CSOs on this site map. See Toronto’s Wet Weather Action Plan.
Kingston:
Questions or concerns about CSOs in Kingston? you can call 613-546-0000. You can also view a historical log of sewage overflows and see the sewage overflow map
Vancouver:
On Nov. 5, 2019, City Council unanimously approved an ambitious green rainwater infrastructure and urban rainwater management initiative called the Rain City Strategy. The strategy and its action plans reimagine how we can manage rainwater Rain City Strategy. Vancouver also has Real-Time Monitoring
Edmonton:
If you have concerns about CSOs in Edmonton, you can contact a 24 hour emergency line at (780) 412-4500 to report the problem.