Some species of cyanobacteria (also known as blue-green algae) can produce toxins harmful to human and animal health. The Jefferson County Water Quality Department monitors the following lakes for harmful blooms:
These lakes have a history of toxic cyanobacteria blooms, are monitored weekly in spring and summer and sampled for toxins monthly if blooms are visible. Other lakes are monitored as time and budget allow. Laboratory results are generally obtained by Friday and lake status is updated on this page. View the Cyanotoxin Hazards page for more information about toxic cyanobacteria blooms.
Lake conditions can change rapidly and lake status may have changed since the last sample was taken. Sampling is only done at one access point on the lake and conditions may be different elsewhere on the same lake. Regardless of what is posted here, if you observe a green paint-like scum or bloom on a lake follow the recommendations listed at the warning level. If you observe a bloom in a Jefferson County lake, please report it by calling 360-385-9444.
What the Status Sign Means
No toxins detected in sample, no toxic species present and no bloom visible. Note: there is no sign posted when the lake is clear.
Toxic Algae Info When in doubt, STAY OUT!
Toxic algae blooms happen in this lake
Avoid areas of scum
WARNING TOXIC ALGAE PRESENT Lake unsafe for people and pets
Do not swim or water ski.
Do not drink lake water.
Keep pets and livestock away.
Clean fish well and discard guts.
Avoid areas of scum when boating.
Call your doctor or veterinarian if you or your animals have sudden or unexplained sickness or signs of poisoning
DANGER KEEP OUT OF LAKE
Lake closed due to toxic algae
Call your doctor or veterinarian if you or your animals have sudden or unexplained sickness or signs of poisoning.