CONTACT: Renae Miller, Public Information Supervisor, Thurston County Public Health and Social Services, (360) 463-0362 or tcphss.pio@co.thurston.wa.us; Dr. Jen Freiheit, Director, Thurston County Public Health and Social Services

Toxic Algae Health Advisory in Effect for Clear Lake & Offutt Lake 
Toxic levels are above the threshold for health concern. 

OLYMPIA – Thurston County Public Health & Social Services is reporting a toxic algae bloom in Clear Lake & Offutt Lake. 

Lab results from a sample taken from Clear Lake on 09/21/2026 detected Microcystin toxin levels at 77.0 µg/L, which is ABOVE the state recreation guideline of 8.0 µg/L. 

Lab results from a sample taken from Offutt Lake on 09/21/2026 detected Microcystin toxin levels at 10.5 µg/L, which is ABOVE the state recreation guideline of 8.0 µg/L.

Microcystins are a liver toxin and a possible human carcinogen. Microcystins can also cause illness in livestock and pets that drink affected water. Staff will continue to collect weekly samples until they receive two consecutive weeks of samples with microcystin levels below state recreational guidelines. Even if the lake is visibly clear of algae, toxins may still be present. 

When an algae bloom is present, health officials recommend taking extra precautions to avoid the health risks posed by potential toxins.

• Do not drink the lake water.
• Avoid contact with water containing algae.
• Avoid swimming, wading, windsurfing, and water-skiing in water bodies where algae blooms are present.
• Keep pets and livestock away from where algae blooms are present.
• Do not eat fish that come from the lake during an algae bloom.
• Avoid areas of scum when boating.  

For more information about toxic algae blooms and health risks, and to see all Thurston County Algae Alerts, visit: www.thurstoncountywa.gov/algae-advisories