Green Lake Closure Signs Have Been Taken Down


On October 2, 2012 Seattle Park Department closed Green Lake to wading, swimming, and wet water boating activities in response to test results showing a high level of microcystin, a toxin produced by a cyanobacteria (bluegreen algae) that exceeded the guidance levels for recreational waters.

Green Lake Is Open

The samples collected November 26 showed the level of microcystin to be less than the minimum detection limit for the third week in a row. King County requires that the level stays less than the guidance level for three weeks before removing restrictions. The Parks Dept has removed the closure notice signs.

King County Department of Health and the Seattle Park Department make the determination to remove the closure notices when the test results have been below the guidance levels for the required amount of time. State guidelines require just two weekly tests below the guidance level.

Test results for many lakes including Green Lake are posted at nwtoxicalgae.org. Go to the website and search for Green Lake to find Green Lake test results. If you have questions or comments or observations you can email FOGL President Garet Munger.

We urge you to join with other Friends of Green Lake at our monthly meetings as we learn more about algae and the lake. See meeting notices elsewhere on this page.

In the meantime it is always good cautionary practice to keep dogs from entering and drinking the lake water when you think there is algae present. Be especially careful if you notice there is a bright green scum on the water.