West Duwamish Wet Weather Storage Facility
Soil sampling at tank site near 1st Avenue bridge starting week of May 16
In early May, crews will mark the locations of existing utilities and sample locations with paint to prepare for groundwater and soil testing. As early as May 16, crews will use a truck- or track-mounted drill rig, like the one pictured below, to collect soil samples and construct groundwater monitoring wells. Once drilling is complete, crews will restore the surrounding surface.
Read more HERE .
King County WTD is building a storage tank near the 1st Ave S Bridge that will reduce water pollution from the South Park and Highland Park drainage basins into the Duwamish River.
Like many cities around the country, older parts of King County’s sewer system use the same set of pipes to carry both sewage and stormwater to a treatment plant. During storms, the pipes can fill with stormwater that runs off roofs, driveways and streets. When the system is overwhelmed, it is designed to overflow. These overflows are called Combined Sewer Overflows, or CSOs.
To keep the sewer system working and to prevent sewer backups, the excess water and sewage is released into our local water bodies through CSOs. However, CSOs pose a risk to public health and the environment. Over the past several years, King County has been planning a project to reduce CSOs from the South Park drainage basin into the Duwamish River. Our requirement is to reduce CSOs to no more than one overflow per year on average.
The West Duwamish CSO Control Project is moving forward with a storage tank to hold stormwater and wastewater during large storms. The tank will prevent raw sewage from spilling into the Duwamish River during these storms. After the storm, the water will flow to West Point Treatment Plant for cleaning.
Contact Kristine Cramer, community services lead at:
Amelia Bahr at:
If you’d like to receive email or text updates on the West Duwamish CSO Control project:
Back to the capital projects overview map .