Health - Wiser Lake Updates

Posted on: November 21, 2023

Microcystin Biotoxin Below EPA Limit in Wiser Lake and Silver Lake

Recent water sampling at Wiser Lake and Silver Lake detected microcystin levels below the maximum safe level established by the US Environmental Protection Agency. Whatcom County Health and Community Services has lifted the warnings for residents to avoid water contact at Wiser Lake and Silver Lake. This includes the warning to not allow pets to swim in or drink from the lakes. 

Microcystin is an algal toxin that primarily affects the liver. Microcystin may cause abdominal pain, nausea, vomiting, headache, diarrhea, sore throat, blistering around the mouth, and pneumonia. Algal toxins occur naturally, but human and animal activity can impact bloom severity. Nutrients in fertilizer, pet waste, agricultural runoff and wildlife waste provide food for algal growth.

You can learn more about harmful algal blooms at or at

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