Clear Lake residents with private water treatment systems have been put on notice for the second successive year that their household water may not be safe to drink or use for brushing their teeth.

Lake County health officials issued a warning Friday about early and abundant blue-green algae blooms in Clear Lake that could produce dangerous toxins, though they have yet to receive results from ...

California's largest freshwater lake has turned a lurid green thanks to a huge algal bloom, as seen in pictures taken from space. Situated around 120 miles north of San Francisco, Clear Lake has long ...