FILE – Rain treatment center

Andrew Wheeler, the U.S. Environmental Protection Agency's Acting Administrator, arrives to talk to reporters, Wednesday, Oct. 3, 2018, after touring the Georgetown Wet Weather Treatment Station in Seattle, a project funded by a low-interest loan from the EPA. The facility will treat millions of gallons of polluted stormwater that currently flows into Duwamish River during severe rainstorms. (AP Photo/Ted S. Warren)

(The Center Square) – King County’s latest initiative to aid in the preservation of the Duwamish River and Puget Sound is close to being completed.

As the Puget Sound region starts to see more and more rain, it becomes more likely that heavier rains cause sewer pipes to overflow, which sends polluted runoff into the Duwamish River. The county-owned Georgetown Wet Weather Treatment Station will be able to treat up to 70 million gallons of polluted stormwater per day during severe rainstorms, according to the county.

The unique treatment station is currently one of the county’s largest capital projects with a price tag of $275 million. On-site construction of the facility began in April 2017.

“Our state-of-the-art treatment station in Georgetown will help protect the Duwamish River for the next century - another down payment by this generation on a resilient climate future,” King County Executive Dow Constantine said in a statement. "This major capital project builds on progress we have made throughout the Green [and] Duwamish Watershed to better protect water quality and habitat for people, fish and wildlife.”

Crews operating the treatment station will remove large solid waste from the rain water through screening, then settle out finer solids from the water and then disinfect the water before it enters the Duwamish River through an outfall pipe. 

King County said it will install art features to the station early next year. One art feature will light up the facility as water moves through the treatment process. Another will recreate rain events inside a 35-foot-high clear cylinder. 

To match the environment surrounding the Puget Sound region, the facility is designed with a plant-covered roof, rain gardens, solar panels and cisterns to irrigate the landscaping with captured rainwater.

This capital project adds to a list of King County-led efforts to clear the Duwamish River. Previously, the county’s Solid Waste Division removed nearly 2,000 toxic-coated pilings from the river. The King County Parks Department also became the largest park agency in the U.S. to be certified Salmon-safe for its work to improve the water quality of the Duwamish River.

Staff Reporter

Spencer Pauley reports on Seattle and the King County area of Washington. He was previously an independent filmmaker and worked on "The Clinton Affair," a documentary series investigating the impeachment proceedings of former President Bill Clinton.