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Harmful algal bloom found at Hauser Lake

algal bloom.jpg
Posted at 12:55 PM, Aug 12, 2022
and last updated 2022-08-12 14:56:06-04

HELENA — HELENA - Lewis and Clark Public Health (LCPH) says a harmful algal bloom has been identified at Hauser Lake near the Clark’s Bay Day Use Area.

Sampling performed LCPH on Aug. 10, 2022, indicated the presence of blue-green algae species producing microcystin toxin.

For reference, both the state of Montana and the US Environmental Protection Agency recreational water recommendations use 4 parts per billion (ppb) as the warning level for microcystin toxin.

The testing on Aug. 10 indicated a level of microcystin at or above 10 ppb.

LCPH will retest for microcystin toxin in the coming weeks and will continue to monitor other harmful algal blooms (HAB) in county water bodies.

Sampling at the Lake Helena Boat Launch on Lincoln Road East, the Causeway Boat Launch, and Canyon Ferry Lake at Hellgate Campground also indicated the presence of blue-green algae.

These sites tested negative for toxins. Users of these areas should still be cautious as conditions may rapidly change.

Public health officials advise the public to avoid exposure to any water that may contain harmful algae. Families should be especially vigilant with children, pets, and livestock.

Direct contact, ingestion, or inhalation of cyanotoxins may irritate the skin, eyes, nose and respiratory system or cause nausea, vomiting, diarrhea, or headaches.

If you suspect a HAB-related illness in a person or animal, call Poison Control at 1-800-222-1222 and seek medical attention.

Report a suspected HAB at or call 1-888-849-2938.