Much of the treated wastewater King County dumps into the Puget Sound will continue to violate state clean water standards for months, King County officials said Thursday, following severe rains that damaged a sewage plant.
Flooding at the West Point treatment plant in Seattle’s Magnolia neighborhood has reduced the plant’s operation to 50 percent. The plant currently does not have adequate capacity to perform state-mandated secondary treatment of the tens of millions of gallons of wastewater and raw sewage that pass through it daily.
“We’re weeks out on getting it back up and running but I don’t have a good estimate on that right now,” said Mark Isaacson, the county’s wastewater treatment director.
Isaacson said the damage to the plant — service corridors filled with 10 feet of water at the height of the storm — was considerable.
“If I could employ every electrician in the country, I’d do it,” he said.
Seattle’s stormwater and sewage system was designed decades ago. The system eventually combines both sewage and stormwater into one pipe. When heavy rains hit Seattle, the system can be overwhelmed.
Since the most recent severe rains began on Feb. 9, more that 260 million gallons of untreated wastewater have flowed into the Sound from the West Point plant. Considerably more has dumped into the sound during 14 hours of additional flooding between 4 p.m. Wednesday and 6 a.m. Thursday, but the county hasn’t yet been able to assess that amount.
The West Point plant when fully operational can process 450 million gallons of wastewater each day. Most winter days it processes considerably less, in the neighborhood of 145 million gallons. But record rains can overwhelm the facility and the county lacks enough capacity to divert the additional flow. So a portion of it – in this case millions of gallons – ends in in the Sound in the form of raw sewage.
A spokesperson with state Department of Ecology said the state is monitoring West Point and that its current crippled operation – regardless of rainfall – won’t be able treat water well enough for state standards.
“We’ve reported and have been working with the Department of Ecology since the morning of the 9th when this started,” Isaacson said. “They are well aware what’s going on.
“They have the potential to fine us. I am sure they will review our work.”
More rain is expected in coming days.
Seattle and King County were both fined in 2016 for other sewage overflows into the area’s bodies of water.