Renton residents received yet another warning this week: Gene Coulon Memorial Beach, the southernmost swimming spot on Lake Washington, has been closed for the sixth time this summer. Tests conducted on August 31 revealed that two of three sampled locations recorded bacterial counts well above the 320 colony forming units (CFU) per 100 ml safety limit, with one sample reaching a staggering 5,600 CFU/100 ml.
What the numbers mean
The county’s water‑quality laboratory measures CFU to gauge the amount of biological waste—whether from people, pets or wildlife—present in the water. Levels above 320 CFU/100 ml indicate a heightened risk of illness for swimmers. While one sample at the beach showed a relatively low 55 CFU/100 ml, the other two samples far exceeded the acceptable range, prompting the immediate closure.
History of closures this season
This is the sixth closure since the season began. The first test of the year, performed on May 11, recorded an average of 5,033 CFU/100 ml, with a single sample spiking at 14,000 CFU/100 ml. Since then, King County has been testing more than two dozen lake beaches weekly from mid‑May through mid‑September to protect public health.
County response and remediation plan
When bacterial levels rise, King County initiates a multi‑step response aimed at identifying and eliminating the source of contamination. Officials work with local sewage utilities to investigate possible leaks or spills and may conduct additional testing to pinpoint problem areas.
Beach managers receive specific guidance to reduce future contamination, including:
- Reminding visitors that dogs are prohibited on the swimming beach and that feeding geese or ducks near the water is discouraged.
- Cleaning goose droppings from docks to keep waste out of the swimming area.
- Using “scare tape” or trained dogs to deter geese from congregating near the beach.
- Renovating docks to improve water circulation.
- Improving drainage in the park to limit runoff that carries waste into the lake.
- Reducing the amount of waste entering nearby streams.
These measures are intended to lower bacterial counts so the beach can safely reopen for families and swimmers.
What residents can do
King County advises anyone planning to swim at Gene Coulon Beach to stay out of the water until the bacterial levels return to safe limits. Residents can help by keeping pets off the swimming area, avoiding feeding waterfowl, and reporting any visible sewage spills to the county’s environmental services department.
For up‑to‑date information on beach closures and water‑quality data, visit the King County website at kingcounty.gov.
Original reporting: Renton Reporter — read the source article.
