Main Page Content

Friday, July 30, 2021 | 5:00 p.m. | Windsor-Essex County

The Windsor-Essex County Health Unit (WECHU) is issuing a blue-green algae bloom advisory for the south shores of Lake St. Clair. This advisory is based on recent lab results for microcystins in Lake St. Clair by the local municipal water treatment plants. The advisory will remain in effect until future test results are at an acceptable level below 1.5 parts per billion (ppb). Residents on the municipal drinking water system can drink the water, unless they are notified otherwise. Routine water testing is done by the municipal water treatment plant.

For Owners of Wells and Cisterns:

Residents that use wells or cisterns that draw water directly from Lake St. Clair (such as private cottages with wells) are advised not to drink the water unless they are routinely testing for microcystins using a licenced lab and results show levels less than 1.5 ppb. This is recommended for adults and children 6 years of age and older, their pets, and livestock animals. Children under age 6 should only drink bottled or municipal water. For all infant feeding preparation, only bottled or municipal drinking water should be used after boiling.


If the water looks cloudy or like green paint or pea soup, they should avoid swimming.

Infants and young children (under age 6) should not swim or play in the water. For adults and children 6 years of age and older, they should swim with caution and rinse off after swimming.

Do not allow pets to drink lake water during a blue-green algae bloom as they may suffer serious health risks including death.

Health Risks

The most common toxins produced during a blue-green algae bloom are called microcystins. Those most “at-risk” are children 6 years of age and younger. Contact with microcystins can produce the following negative health effects in humans:

Skin Contact

Itchy, irritated eyes and skin if you swim, bathe, or shower in contaminated water.


Small quantities - headaches, fever, diarrhea, abdominal pain, nausea, and vomiting.

Large quantities - more serious health effects may occur such as liver damage.

For more information on blue-green algae blooms, please visit the Health Unit website at


Related Content