Algae bloom in Echo Lake - public advised to avoid contact with water

Algae bloom 9-14-2012 Echo Lake
Photo courtesy City of Shoreline

On July 25, 2013, City of Shoreline surface water quality staff sampled an algae bloom on the west side of Echo Lake. On July 31, 2013, the lab reported that the sample produced a value of 9.1 ug/L of microsystins, a liver toxin. Pursuant to Department of Health protocols, any sample above 6 ug/L is above the threshold for recreational use. Caution signs have been posted in two areas on the Lake. These signs advise against contact with the water at this point.

Protocol is to sample three times to track whether the toxin levels are rising or falling. A second sample was taken on July 29, 2013. Two more samples will be taken on the next two Mondays. Further posting and sampling decisions will be based on the results of those samples. 

10-1-2012 Algae bloom in Echo Lake
Photo courtesy City of Shoreline

As happened last year, algae may persist in the lake for an extended period. There is no way to tell whether the algae is toxic just by looking at it. If you see an algae bloom at any time, you should contact the City to have a sample tested.

King County provides an overview of monitoring and the toxin. 

Several lakes have been closed this summer. A map of current closures can be found here. Echo Lake was closed last year, prior to that, the last time Echo Lake was closed was in 2009. 

More information about the Department of Health regulations can be found here.