In the early morning hours of Feb. 9, heavy rainfall and a high tide combined to knock off line Seattle’s 52-year-old West Point wastewater treatment plant. As the waterfront plant flooded and equipment failed, system operators routed up to 200 million gallons of combined runoff and effluent—90% stormwater and 10% wastewater—to an emergency bypass outfall, then into the Puget Sound.
West Point handles between 90 million to 300 million gallons a day during storm seasons. Weeks later, West Point was still at 50% capacity for primary treatment and providing no secondary treatment, even though that section of the plant wasn’t damaged. Instead, operators were diverting flows to the plant’s deepwater outfall three-quarters of a mile offshore, on the bottom of the Puget Sound.