While the city of Montreal says it’s studying the idea of creating more beaches on its territory, CBC’s French-language service Radio-Canada has learned that sewage waste is dumped directly into the St-Lawrence River and the Rivière des Prairies after heavy rainfalls.

The data collected near one of the proposed beach sites in the borough of Verdun shows that, on some days, the levels of coliform bacteria were more than 20 times higher than the acceptable levels for swimming.

Many surfers and kayakers who use the water said they’ve noticed the problem.

“There was toilet paper, dirty water ... condoms sometimes. While we were surfing the waves, we saw that just passing underneath us,” said Hugo Lavictoire, a surfing instructor.

Lavictoire said the dirty water has sometimes made him sick.

“I just had an ear infection -- many, many times within the same summer, and it was obviously related to the poor quality of the water,” he said.

Pipes flow into river

Experts say coliform levels found at certain spots in the river can be thousands of times above what's considered acceptable for swimming.

That's because after a storm, Montreal's sewage waste mixes with rainwater.

“If I fell into the water here, or if I swallowed a cup of water, the chances that I would not get gastro would be very low,” said Daniel Green, an environmental activist and co-founder of the group Société pour Vaincre la Pollution.

About 150 pipes flow directly into the river.

A city website shows that in 2013, the water quality of the proposed beach site in Verdun was poor on several occasions. (Radio-Canada) The waste is eventually washed away by the current, but people who use the river say until then, there is no system to warn them about the water quality.

“Is it possible to have an alert or a notice, just to say ‘OK, we dropped bad water in the river so you should wait?’” said Lavictoire.

City officials said that water enthusiasts should follow a general rule of thumb.

“After or during big rainfall, stay away from the water because there is a risk of contamination. Wait 24 hours for the currents to wash away the pollutants,” said Chantal Rouleau, Montreal’s executive committee member responsible for water and water infrastructure.

A city website shows the results of water quality tests taken along Montreal's shores.

Rouleau said the city is working on a long-term solution — it plans to build reservoirs to store water during rainfalls so that it can be treated rather than dumped straight into the river.