LAKE SAMISH, WA (MyBellinghamNow.com) – A potential health risk has prompted a warning for residents who draw their drinking water directly from Lake Samish.

Whatcom County Health and Community Services issued a water quality advisory Tuesday, July 28 after a recent test found increased levels of microcystin on the east shore of the lake.

Microcystin is a toxin produced by algae that can make water unsafe to drink. The advisory only applies to residents who draw their water directly from the lake through a private drinking water system.

The tests results showed a safe level for healthy adults and children over six, but the toxin poses a heightened risk to infants, pregnant women, elderly people and those with weakened immune systems.

The health department is advising residents to use bottled water unless they can confirm their filtration system removes cyanotoxins.

The advisory does not currently affect swimming, bathing or handwashing. All pets should be kept out of affected areas of the water.