AVERY COOPER: Whitman County leaders are lifting a health advisory for a toxic algae on the Snake River. The harmful algal bloom covered about 50 miles of the river.

Public health leaders first noticed it in August. This is the fourth year in a row a bloom has shown up in the area.

Water samples had tested positive for a liver toxin called Microcystin. The county continued taking routine water samples. And now they’ve had two samples in a row that are below what the state considers toxic.

Health leaders say it’s really hard to find out what’s causing these algal blooms. But they’ll keep monitoring the Snake River next year.