Saskatchewan

Foam on Wascana Creek not risky: biologist

Big patches of foamy bubbles appearing on Regina's Wascana Creek are nothing to worry too much about, a biologist says.
Foamy bubbles, in patches up to 1.5 metres wide, have been flowing down Wascana Creek. (CBC)

Big patches of foamy bubbles appearing on Regina's Wascana Creek are nothing to worry too much about, a biologist says.

From a distance, what looks like small icebergs dotting the creek are actually agitated cocktails of phosphorus and organic matter.

"The water in Wascana Lake has got lots of organic matter in it, like a grass stain except dissolved in the water. It's also got lots of phosphorus, which is one of the things you used to find in detergents and it was there to allow you to turn that organic matter into bubbles," said Peter Leavitt of the University of Regina.

"As the water moves under Albert Street bridge, it's just putting it into a washer on a high spin cycle, and you get lots of foam coming out."

Leavitt said it's not necessarily bad that the bubbly patches, up to a metre and a half wide, are flowing down the stream, even if the phosphorus is coming from agricultural runoff.

"This is a fertile part of the country. There's lots of phosphorus in the soils, there's lots of phosphorus being used for fertilizer," he said. "Wascana Lake is one of those lakes that has just an unbelievable amount of phosphorus, both naturally and from land use activities upstream. It's not dangerously high, but it is higher than you'd see in most other lakes."  

The torrential rains that have flooded southern Saskatchewan over the last two months are responsible for washing a lot of that phosphorus, plus the organic matter, into waterways.

As well, the heavy rains of the last few days have sent more water pouring over the weir at the Albert Street Bridge, causing the water to churn harder.

A possible downside is that, as temperatures get hotter over the summer and the sun emerges, algae will flourish in the phosphorus-rich water. Some kinds of algae can cause rashes after coming into contact with people who have sensitive skin. Other kinds are liver toxins, Leavitt said, but that's more of a problem for animals that would drink the water in sizeable quantities than it is for humans.

"If you see the water getting really green," Leavitt cautioned, "I'd keep your dog away."

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