South Park Water Quality Facility

Project description

Seattle Public Utilities (SPU) plans to build a water quality treatment facility along the Duwamish River in the South Park neighborhood. The facility will remove a variety of pollutants common in urban stormwater runoff from a 240-acre drainage basin that discharges into the Duwamish. Along with other projects that reduce flooding in the industrial and residential areas of South Park and the ongoing Superfund cleanup effort, the water quality facility will help keep the Duwamish River clean for people and fish.

Location

The water quality facility is located on a 3-acre site bounded by 8th Ave S to the west, S Kenyon St to the south, and the Duwamish to the north and east. 

What's happening now?

SPU recently evaluated and selected treatment technologies for the water quality facility. The facility will consist of a roughing filter (a bed of pea gravel or similar material to catch larger sediment) and bioretention cells. These two approaches will work together to filter and remove pollutants from the stormwater before it is discharged to the river.

SPU is in the process of developing a project site plan that includes the water quality facility and additional community amenities. The project has limited space to accommodate different uses. SPU is engaging with community groups, industry, and residents to better understand how people would use the site and what amenities rank most highly to help inform the final site plan and which amenities are included.

Community benefits

The South Park Water Quality Facility project will: 

• Remove pollutants from stormwater before it flows into the Duwamish Waterway
• Remediate soil and groundwater from a historically contaminated site
• Connect community spaces along the Duwamish Waterway.

Community engagement

SPU is committed to providing timely information and updates on project activities. Updates may be available in multiple formats: websites, emails, drop-in sessions, virtual and in-person briefings, and public meetings. 

There will be opportunities for the public to engage and provide feedback throughout the project. SPU will be seeking community input on the different possible site designs through printed and online surveys, public open houses, and meetings with community groups throughout 2025. Check back for information about upcoming opportunities to get engaged and sign up for the project listserv. 

As part of early engagement for the South Park Water Quality Facility, the project team conducted eight youth workshops with the Duwamish Valley Youth Corps (DVYC) and the Duwamish Valley Sustainability Association (DVSA) in the Fall of 2024. The workshops focused on co-designing the surplus land outside of the Water Quality Facility’s footprint. Students learned about South Park’s natural and cultural history, transportation connections, land use, planned capital projects, sea level rise adaptation techniques and habitat restoration projects. Their designs were showcased at the DVYC Environmental Justice Symposium in November 2024, where families gathered to celebrate their work. Please refer to the Youth Engagement Memo for more information.