The local conservation authority and health unit have warned people not to swim in Conestogo Lake due to the presence of blue-green algae.
On Aug. 30 the groups announced that warning signs were being posted at the lake advising people about the algae, which contains the toxin microcystin and can cause illness when ingested by people or animals.
Cottagers were also notified of the algae bloom, which was first noticed when mats of decaying algae appeared on the shoreline. There have been no reports of human illness, officials say, but samples taken on Aug. 26 show the algae contains microcystin.
Officials with the Grand River Conservation Authority (GRCA) and Wellington-Dufferin-Guelph Public Health are warning people not to swim in the reservoir, come in contact with the algae, allow children and pets to go near the algae, eat fish from the lake or use the water for drinking or any other purpose. Boating is allowed, but boaters should avoid touching the algae.
Drinking water
About 24 hours after the GRCA and public health issued the algae warning, Mapleton announced it was offering free drinking water.
The municipality opened a drinking water filling station at the PMD Arena in Drayton for any residents or cottagers affected by the algae.
Township officials say the filling station will remain open “until the lake water quality concerns are resolved.”
Portable containers can be filled at the arena Monday to Friday from 9am to 4pm.
About algae
When algae die, microcystin is released in the water. It breaks down in five to seven days. Algae blooms occur naturally during hot, dry weather. Algae feed on phosphorous, a natural chemical found in soil as well as in manure, fertilizers and human waste.
A similar algae bloom warning was issued at Belwood Lake in mid-August.
Updates and more information on the algae is available at www.grandriver.ca.
