Mark Clairmont |

MUSKOKA LAKES The health unit is advising as of Aug. 27, that residents around the Dee Bank area (west end) of Three Mile Lake to avoid using the lake water for drinking or food preparation, including breastmilk substitute (infant formula).

And it says boiling the water will not destroy the toxins, and home treatment systems should not be relied on.

The Simcoe Muskoka District Health Unit (SMDHU) says in a release today, that it has been advised by the Ministry of Environment, Conservation and Parks (MECP) that laboratory tests have confirmed the presence of a blue-green algae bloom in the Dee Bank area (West end) of Three Mile Lake.

This is the second straight year for a bloom in the lake.

On July 31, 2018, another casse was reported. It was only lifted this past June 6, according to an SMDHU website link.

It was the same for several other lakes last summer.

See the related graphic below:

Algae blooms have been a problem in Muskoka for decades, including most recently the past year in Muskoka Lakes and other area lakes. (SMDHU graphic 2019)

Wind and water currents can change the location of algae blooms, which may make the water look bluish-green, or like green pea soup or turquoise paint. Swimming and other water sport activities should also be avoided in areas where a blue-green algae bloom is visible.

Exposure to blue-green algae, whether for drinking, swimming, cooking or through eating fish caught from the Dee Bank area of Three Mile lake, may result in illness. Adverse health effects are mainly caused by drinking water that is contaminated with blue-green algae toxins. Symptoms from consuming toxins can include headaches, fever, diarrhea, abdominal pain, nausea and vomiting, and can be more serious if water is swallowed in large quantities.

SMDHU and the MECP will continue to monitor the lake and updates will be posted on the health unit’s website at

To learn more about blue-green algae visit the health unit website, or call Health Connection weekdays from 8:30 a.m. to 4:30 p.m. at 705-721-7520 or 1-877-721-7520.

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