Island County Lakes Program

Island County Lakes Monitoring Program​

The Island County Lakes Program monitors conditions of the four public fresh water lakes with public access points  in order to protect public health. The parameters for the monitoring program is primarily for harmful toxins from cyanobacteria (formally called blue green algae). To The four lakes monitored in this program are:

Cranberry Lake, Oak Harbor WA

Goss Lake, Langley WA

Lone Lake, Langley WA

Deer Lake, Clinton WA

Lake Closures Policy is based on state guidelines set in June of 2021 (CLICK HERE) which requires local health jurisdictions to post a WARNING when microcystin levels are 8 μg/L or higher, anatoxin-a levels are 1 μg/L or higher, cylindrospermopsin levels are 15 μg/L or higher, and/or saxitoxin levels are 75 μg/L or higher. A lake CLOSURE is required when toxin concentrations are extremely high (> 2,000 μg/L microcystins or > 300 μg/L anatoxin-a) or if pet illnesses/death or human symptoms are reported. 

LAKE STATUS (From NWtoxicalgae.org map)

* 2,000 (μg/L) microcystin is the State Maximum Limit before closure