The Leeds, Grenville and Lanark District Health Unit is reminding the public of the dangers of potentially harmful algal blooms.

Algal blooms including blue green algae are a natural seasonal phenomenon that may appear in lakes, rivers and ponds according to the health unit. They say many blooms are harmless but some have toxins that are harmful to humans and animals.

The health unit says surface water is never a safe source of drinking water without effective treatment. Toxins released by harmful algae are not removed by treatments commonly used like boiling, chlorination or ultraviolet light treatment. The health unit suggests consulting a water treatment specialist if your drinking water comes from a lake and choosing another source for drinking water.

For recreational water use, the health unit says to consider multiple things when going back to using the water after a harmful algae bloom.

  1. Faster moving water will dilute and move the toxins out of an area more quickly, which will decrease the risk to health. A local assessment is useful to assess risk as there is different water flow at different properties.
  2. If someone has skin irritation, do not to go in the water. This is the first sign that there is a significant level of toxin in the water. If the water is moving well a few more days will help clear algae unless another bloom has occurred.
  3. Do not swallow the water. The water in lakes and rivers always has the potential to be infected with bacteria, viruses and other microbes that can affect health. Young children are more likely to swallow water so it is critical to observe them carefully in the water.
  4. Be cautious about eating fish caught in water where a harmful algae bloom has occurred. Toxins are concentrated in the liver. Avoid consuming the liver, kidneys and other organs of fish caught in an area affected by potentially harmful algae

The health unit encourages residents to contact the Spills Action Center at 1-800-268-6060 to report any new potentially harmful algae blooms. The number of blooms and the location can be monitored. Taking pictures of an active bloom is also encouraged as this may help identify the type of algae.