Seattle’s Seward Park swimming beach will reopen Saturday, after two consecutive days of testing showed the water safe for recreation. But a four-block stretch of Lake Washington remains closed to contact by humans and pets pending further testing.
The section of Lake Washington shoreline near Wednesday’s sewage spill site — from South Angeline Street north to the 4200 block of Lake Washington Boulevard South (including Lakewood Moorage) — remains closed. Additional testing will be conducted this weekend.
Seattle Parks and Recreation, Seattle Public Utilities (SPU) and Public Health–Seattle and King County closed areas of the lake Wednesday after problems with a pipe valve caused an estimated 12,000 gallons sewage to spill near South Alaska Street and Lake Washington Boulevard South, more than a mile north of the Seward Park beach.
Wednesday and Thursday, SPU sampled eight locations along Lake Washington Boulevard for fecal coliform bacteria, an indicator of sewage. All locations but one, including the Seward Park swimming beach, showed extremely low concentrations of fecal bacteria.
Water tests over the past two days near the spill site showed an elevated level of bacteria. The area will be tested again over the weekend.
SPU has determined that the spill occurred when a repair crew — relying on an outdated reference document — accidentally closed an electrically controlled pipe valve that should have remained open. Closing the valve caused sewage to spill into the lake. SPU is reviewing its procedures to ensure this type of mistake does not reoccur.
Seattle Parks and Recreation and SPU have posted warning signs in the area, which will be removed as soon as possible.
King County routinely monitors water quality at all swimming beaches in the area. These results are reported at http://green2.kingcounty.gov/swimbeach/.
Learn more about Seattle Public Utilities, at: www.seattle.gov/util.
Watch a short video about SPU.
Follow SPU on Twitter: www.twitter.com/SeattleSPU.