Mary Callahan, THE PRESS DEMOCRAT
The Russian River tested clean this week for a toxin related to blue-green algae that prompted cautionary signs at 10 popular beaches last month and in each of the past two summers.
The river remains open to swimming and other recreation. But warning signs urging visitors to avoid ingesting river water will remain at 10 popular beaches between Cloverdale and the river mouth as a precaution against exposure to the neurotoxin involved, the Sonoma County Department of Health Services said.
The weekly sampling suggests the threat, already minimal, could be diminishing. But precautions can only be lifted after several weeks pass without detection of the neurotoxin called anatoxin-a, county health personnel said.