Alberta Health Services has issued advisories for Pigeon Lake, south of Edmonton, and Lac La Nonne, northwest of the city.
People are urged to see a doctor if they come in contact with affected water and suffer adverse health effects.
Dr Katherine Koliaskis, medical officer of health with AHS, says boiling the water to try to get rid of the algae before drinking it doesn't work.
Don Fleming, mayor of the summer village at Pigeon Lake, says the wind moves the algae around, and there's a good chance the material will show up at the lake's popular Ma-Me-O Beach.
Fleming says algae blooms seem to be a phenomenon that's becoming more widespread, but he's encouraged that studies are being done by Alberta Environment to try to mitigate the problem.
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