The Renfrew County and District Health Unit is advising residents of Cobden and the surrounding area of a possible harmful algae bloom found in Muskrat Lake.

In a news release, the RCDHU said a plant-like substance was spotted on the surface of the lake recently which resembles a blue-green algae bloom. Testing is underway to determine whether the bloom is harmful.

“[The Ontario Clean Water Agency] is also regularly sampling at the Cobden water treatment plant to ensure the drinking water is safe to consume,” the RCDHU said.

The Township of Whitewater Region says Cobden Beach will be closed to swimming and recreational purposes until test results are received. It notes, however, that the municipal water supply is not affected.

"Please note that although blue-green algae may have been detected in the lake, no blue-green algae have been found in the municipal drinking water and is still safe to drink. There is no public health risk for residents of Cobden who are on the municipal drinking water system," a release from the township says.

Blue-green algae blooms are potentially toxic. They release toxins into the water when they’re damaged or when they start to decay. Direct contact can cause skin irritation and affected water can cause vomiting, nausea, diarrhea and abdominal pain if ingested in higher concentrations.

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.

The RCDHU says it 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," the health unit said.