SEATTLE - The beach at Matthews Beach Park is currently closed after King County Natural Resources and Parks measured high levels of bacteria in the water. People and pets should stay out of the water until further notice.
The three-day average of bacteria levels this week was 301 colony-forming units (CFU), which is a count of the number of bacteria per 100 mL of water. According to King County Public Health, a beach is usually closed if the three-day average is over 200 CFU per 100 mL of water.
Most disease-causing bacteria in Puget Sound come from human or animal waste, according to the Washington Department of Ecology. This could include failing septic systems, sewage spills, boat waste discharge or malfunctions at a wastewater treatment plant.
New water samples will be collected next week and any updates on reopening Matthews Beach will be posted online by King County Public Health.