OLYMPIA- Thurston County Environmental Health officials are continuing to warn about an outbreak of toxic blue-green algae in Black Lake. A second round of testing has shown that levels of the algae toxin are well above the recreational guidance value of 6 parts per billion established by the Washington State Department of Health. The results of the second round of testing on September 27th showed toxin levels 10 times and 100 times the level considered to be safe for recreational activities. Samples taken on September 21nd were the first to show the presence of the blue-green algae toxin, microcystin, in the lake.
Extra warning signs have been posted around the lake in addition to those originally placed at Kenneydell County Park, the public boat launch, and other popular beaches and community areas.
Heath impacts related to blue-green algae toxins can include:
Lake residents and users are advised not to swim in or drink lake water from the affected areas. Children and pets should be kept away from the lake.
- Nausea, vomiting, or acute liver failure;
- Irritation of the gastrointestinal tract, skin or other exposed tissue;
- Muscle cramps, twitching, paralysis, cardiac failure, or death in animals.
Anglers are advised to practice catch and release while the advisory is in effect.
Additional samples will be collected weekly to determine when the toxin is no longer present. The lake will remain posted until toxin concentrations fall below the advisory level.Additional information about toxic blue-green algae can be found at:
- www.co.thurston.wa.us/health/ehadm/swimming/swimming_index.html or