The Renfrew County and District Health Unit (RCDHU), Ontario Clean Water Agency (OCWA) and the
Ministry of Environment Conservation and Parks (MECP) investigated the discovery of a plant-like
substance floating on and around the shore at Muskrat Lake.
The substance is suspected to be a blue- green algae bloom. Results from a water sample taken by MECP are pending to determine if the
substance is a harmful algae bloom. OCWA is also regularly sampling at the Cobden water treatment
plant to ensure the drinking water is safe to consume.
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 Muskrat Lake, 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.
RCDHU advises people using Muskrat Lake 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 and visible, people who use
the surface water for their private drinking water supply should consider an alternate, protected
source of water.
RCDHU will continue to monitor the water conditions on Muskrat Lake. As of July 4, there were no
known algae blooms detected by health unit staff.
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 RCDHU’s website at
https://www.rcdhu.com/healthy-living/safe-water/.