Blue-green algae blooms are a natural seasonal phenomenon that may appear in lakes, rivers and ponds. Some species have the potential to produce toxins which may be harmful to people and animals.
Toxins are released into the water when the algae cells are damaged or begin to decay. Direct contact with the toxin can cause skin irritation and if ingested in higher concentrations, may result in vomiting, nausea, diarrhea and abdominal pain.
The health unit recommends that people using Lake Dore, or any waterbody for recreational or drinking water purposes, should become familiar with blue-green algae so they can make informed decisions about using the water.
Although algae blooms degrade with time, the length of time potential toxins remain in the area is dependent upon local water movement characteristics.
The Renfrew County and District Health Unit advises people using Lake Dore to be on the lookout for algae blooms. If a bloom is visible, please take the following precautions:
• Avoid direct contact with the bloom.
• Avoid using the water in the vicinity of a bloom for drinking, bathing or showering and do not allow children, pets or livestock to drink or swim in the water.
• Boiling the water for drinking purposes should be avoided because boiling may release more toxins into the water.
• Toxins that may be released by blue-green algae are not removed by small scale residential treatment systems such as filtration, chlorination or ultraviolet light disinfection. Surface water is never a safe source of drinking water without effective treatment.
• Residents should not rely on water jug filtration systems as they do not protect against the toxins.
• Avoid cooking with the water because foods may absorb the toxin during the cooking process.
• Caution should be exercised with respect to eating fish caught in water where blue-green algae blooms have occurred. Avoid eating the liver, kidneys and other organs of fish caught in the water.
• On lakes and rivers where blue-green algae blooms are confirmed, people who use the surface water for their private drinking water supply should consider an alternate, protected source of water.
The Renfrew County and District Health Unit will continue to monitor the water conditions on Lake Dore. As of July 7, there were no known algae blooms detected by health unit staff.
The RCDHU recommends that blooms should be reported to MECP at 1-800-268-6060.
For more information, please visit the Ministry of the Environment Parks and Conservation website at http://www.ontario.ca/environment-and-energy/blue-green-algae or the Renfrew County and District Health Unit website at https://www.rcdhu.com/healthy-living/safe-water/.
