Montreal may be embroiled in controversy over its decision to dump eight billion litres of wastewater into the St. Lawrence River, but the same thing is happening in cities across Canada.

École Polytechnique engineering professor Sarah Dorner said while she's happy people are talking about the city's decision, the bigger issue is that it's a frequent occurrence.

This is a very common problem. - Sarah Dorner , École Polytechnique engineering professor

"This is a very common problem. It happens all through the Great Lakes, all through Quebec. There is raw sewage that ends up discharged into the rivers," told CBC Montreal's Radio Noon.

"We haven't been doing a good job communicating what the reality is on a day-to-day basis because this is a problem that occurs regularly across Canada."

Dorner said the issue needs to be solved, paying particular attention to the public health and environmental problems that sewage dumps cause.

Here's a rundown of other Canadian cities where dumps of raw sewage have taken place:

Halifax

Raw sewage was continuously pumped into the Halifax harbour until a new wastewater treatment plant was constructed in 2008. However, sewage continued to be discharged into the harbor unknowingly, when sewer lines were cut during construction.

Winnipeg

Roughly 185-million litres of raw sewage have been dumped into Winnipeg's rivers since 2004 due to the city's antiquated combined-sewer system. The city says that massive upgrades need to be made to the older sewer system, which could cost the city up to $4 billion.

Mr. Floatie is one citizen's attempt to protest the amount of raw sewage that continues to flow into Juan de Fuca Strait each day. (Mr. Floatie/Facebook)

Victoria and Esquimalt

The region pumps about 130-million litres of raw sewage daily into the Juan de Fuca Strait, a channel leading to the Pacific Ocean. Victoria and Esquimalt have been in a longtime battle with the federal and provincial government concerning their sewage treatment practices and have been struggling to find a site for a new treatment plant for years.

Esquimalt citizen James Skwarok even created a mascot to protest the sewage dump: Mr. Floatie, the giant turd.

Toronto

In July 2013, Toronto was pounded with 126 millimetres of rain in under two hours. More than a billion litres of sewage and storm water overflowed onto city streets and cascaded into Toronto's harbour.

Heavy rains often overwhelm Toronto's old sewer system, forcing the city to bypass water-treatment plants and send raw sewage into Lake Ontario.