Gene Coulon Beach in Renton has reopened for public swimming.

On May 27, King County released its most recent bacteria testing results for the local lakes’ swimming beaches and Gene Coulon has the green light.

According to the King County website, water testing at Gene Coulon Beach — the most southern swimming beach in Lake Washington — previously showed that bacteria levels at a high of 360 bacteria per 100 milliliters of sample water on May 12. Due to those high bacteria levels, the county closed the beach for swimming.

When bacteria results are above 320 bacteria per 100 milliliters of sample water, that is when bacteria levels are considered high. If two of the three bacteria samples (labeled “Sample A”, “Sample B”and “Sample C”) are over the 320 bacteria/100 mL threshold, then the county will recommend the public to not swim in that water.

The water at more than two dozen lake beaches that are popular swimming spots are regularly tested for bacteria every year from mid-May to mid-September. If water tests find high bacteria, it means that there are high levels of poop from people, pets, or wildlife in the water, which can carry germs that make people ill.

For more information on water quality in King County’s swimming beaches, visit kingcounty.gov/en/legacy/services/environment/water-and-land/lakes/swim-beaches.