A health alert remains in effect for Olympia's Summit Lake due to a toxic algae bloom.
Thurston County Health Department said Thursday test results showed the algae bloom is producing high levels of the toxin Anatoxin-a, more than double the level for health concern.
More sampling will be done next week. The health alert will remain in effect until samples are within safe levels for two consecutive weeks.
Many residents around Summit Lake depend on the lake for drinking water. The health department advises they should not drink lake water or use lake water for household use until tests show it is safe.