Construction at CSO storage tank site
Stellar J Construction completed shoring removal in early May, and the lid to the storage tank is in place. Crews are now building the above ground ancillary equipment building, and below ground diversion and odor control structures. The 1.5 million gallon tank will store excess flows of stormwater and wastewater and is part of a new combined sewer overflow (CSO) control facility that will reduce overflows of stormwater and sewage to Puget Sound during heavy rain storms.
Second detour on 32nd Avenue West
Southbound traffic is being detoured to the west side of the 32nd Avenue West and northbound traffic to the east side to accommodate work the middle of the street. Crews are building an underground diversion structure that will transfer wastewater from the existing sewer line to the new gravity sewer pipeline. The new 3,000-foot sewer line is part of the new CSO facility in Magnolia.
Motorists and pedestrians should travel slowly, watching for flaggers, other pedestrians and vehicles, and following signs and directions.
Young bald eagles appear larger and darker than their white-headed parents.
Storage tank concrete base and sewer pipeline installation complete!
King County is constructing a new combined sewer overflow (CSO) control facility in Magnolia to reduce overflows of untreated stormwater and wastewater into Puget Sound during heavy rains. At the end of 2014, King County’s contractors completed two important milestones. Stellar J Corporation successfully carried out a continuous concrete pour to install a 12-foot thick concrete base slab for the 1.5 million gallon underground storage tank.
The second component of this facility is a new gravity sewer pipeline. Walsh Construction and Mears Group, Inc. completed the final step in the Horizontal Directional Drilling (HDD) process, pulling almost 3,000 feet of pipeline through a borehole extending from 32nd Avenue West to an exit pit on 23rd Avenue West. During wet weather, stormwater and sewage will be diverted through this pipeline to the newly constructed underground storage tank across from Smith Cove Park.
Why does King County need to do this project?
This project is part of a long-term King County plan to help protect Puget Sound and reduce the number of combined sewer overflows (CSOs) in local waterways. In 2013, King County reported a long term average of 22.7 overflows per year from the Magnolia Outfall. The new CSO Control Facility is designed to reduce overflows to Elliott Bay to no more than one per year on a long-term average. The project is included in a federal consent decree that requires completion by December 2015.
What is the schedule for this project?
Planning and design for this project took place from 2007 to 2013. Construction began in 2014 and is scheduled for completion in 2015.
In recent months, area neighbors have reported sightings of bald eagles that built a nest in Magnolia Boulevard Park above 32nd Avenue West. We are monitoring the eagles until August, when work at the site will be complete. Work activities must adhere to seasonal restrictions to create the least disturbance for the birds. For more information, view the Fall 2014 Newsletter (PDF) or contact Hillary.Schafer@kingcounty.gov.