This story is part of Uytae Lee’s story Stories from here, an original series with the CBC Creator Network. You can watch all episodes of this series on CBC Gem.
Last summer, three beaches in Metro Vancouver were closed to swimmers after high levels of E. coli in water.
And this is a fairly common phenomenon. Almost every year, beaches, lakes and other bodies of water are farm to swim across Canada because there is feces mixed in with the water. Our poop!
So how did this poop get there?
Well, it’s because of what’s called the combined sewer and stormwater system.
Mix sewage with stormwater
When you rinse your things, they flow into a network of sewage pipes that lead to a treatment plant where they are cleaned and treated before the remaining water is discharged into the ocean.
Simple enough, right?
But in a combined sewer and stormwater system, sewage isn’t the only thing that enters those pipes. There is also rainwater.
In a combined system, rain that hits a hard surface like asphalt, glass or concrete also flows into our sewage system to be cleaned and treated.
And this is where we find the root of this problem: the amount of sewage flowing through a city at any given time is fairly constant, but the amount of rainwater a city receives fluctuates wildly. So when there’s a big rainstorm, there’s way too much water flowing through our pipes for the sewage treatment plant to handle.
The result? All excess stormwater and sewage drain into a nearby body of water, whether it’s a stream, lake or beach.
Gray and green infrastructure
This combined system has always been the system of choice for most older cities in North America, which means it’s a problem just about everywhere.
In 2017, more than 167 billion liters of wastewater and stormwater combined has entered water bodies across Canada, all provinces except Prince Edward Island, Newfoundland and Saskatchewan.
So how do you stop doing this?
Well, there are many different solutions and they basically fall into two categories: gray infrastructure and green infrastructure.
“Grey infrastructure” is a more cumbersome approach to dealing with excess stormwater. One example is in Tokyo, where the city has built huge underground caves to hold excess liquid during typhoon season.
Another popular solution is to completely separate stormwater and wastewater into different pipe networks, so that the wastewater can be routed to treatment plants, while the stormwater can simply flow into the ocean. .
But these solutions are incredibly complicated, expensive, and don’t always work. And this is where green infrastructure comes in.
Easier to be green?
In nature, there are no pipes. When it rains, water is absorbed by the ground or pooled in streams and rivers that flow into lakes and oceans.
“Green infrastructure” is what happens when cities attempt to emulate this process in an urban area. This includes making green roofs or other permeable spaces that collect and absorb rainwater. It can even be as simple as planting more trees, which are very good at absorbing water.
But this approach is not perfect either. Green infrastructure doesn’t make sense everywhere, and the science behind it is admittedly less predictable than just running water through a pipe.
What I really understood was that it will take many different solutions to manage our wastewater and stormwater.
And I’m hopeful that if we keep our eyes on the prize, one day maybe – just maybe – we’ll finally stop dumping sewage into the ocean.
Learn more in Stories About Here: How to stop dumping sewage into water
About this series
Stories from here is an original series with the CBC Creator Network that explores the urban planning challenges facing communities across Canada today. In each episode, we delve into often-overlooked issues in our own backyards – whether it’s the shortage of public toilets, leaking sewers into water, or the bureaucratic roots of the housing crisis. Through it all, we hope to inspire people to become more informed and engaged members of their communities.
You can watch all episodes of this series on CBC Gem.