We test the water at more than two dozen popular lake swimming beaches during mid-May to mid-September. If water tests find high bacteria, this means there is poop in the water from people, pets, or wildlife. Poop can carry germs that can make people sick from swimming or playing in the water.

From mid-May to mid-September test results are available on this site weekly, usually Tuesdays or Wednesdays. 

Note: not all of these beaches may be lifeguarded, and some may be closed by local parks departments for reasons other than bacteria levels. Visit Public Health’s Water Safety website for lifeguard locations and hours, life jackets, cold water safety, and more.

For marine beach bacteria, visit the Department of Ecology's BEACH Monitoring website. For toxic algae in lakes, visit the Northwest Toxic Algae website.