South Magnolia CSO Control Project
July 21, 2014 Update
King County’s contractor is working overnight on the on-ramp from the Smith Cove/Elliott Bay Marina area to the Magnolia Bridge. Drivers wishing to use the on-ramp will be detoured to and from 23rd Ave W to the off-ramp during the closure of the on-ramp. Flaggers will direct traffic coming from 23rd Avenue West across the Magnolia Bridge to continue east to 15th Ave W.
Installation of monitoring equipment beginning July 15, 2014.
View project update (PDF, July 10, 2014).
Overnight work in the Magnolia Bridge/Smith Cove area
Alternating ramp closures beginning July 7, and may extend to the week of July 21.
View project update (PDF, July 11, 2014) and news release (July 2, 2014).
Construction highlights for the storage facility and 32nd Avenue West
• Excavation for the 1.5 million gallon storage tank is underway on the County’s site in the Smith Cove/Terminal 91 area. Shoring activities should begin late June/early July.
• Utility service work for storage project is almost complete and includes power line hook ups, water sewer and storm drain services to the site
• The contractor that will build the gravity sewer pipeline is moving into the temporary construction easement on Smith Cove Athletic Field
• Preparations on 32nd Ave. W. will begin the week of June 23, 2014. Early activities will be to remove trees and brush in areas that will be used for drill rig pits and temporary roadways. Crews will also confirm locations of underground utilities using vactor trucks. View project update (PDF, June 18, 2014).
• Crews will soon begin installing monitoring points along the gravity sewer pipeline alignment; one of these locations will be in Magnolia Boulevard Park. We will provide advance notice of these activities as more detail is known.
South Magnolia CSO basin project area
How will the new CSO facility work? View animation.
South Magnolia basin and project location.
King County is building a new gravity sewer pipeline and an underground storage tank in Magnolia. This facility will store peak combined sewer flows so that discharges of untreated wastewater and stormwater are limited to no more than one per year on a long-term average.
Why does King County need to do this project?
This project is included in a federal consent decree that requires completion by December 2015.
View meeting calendar for upcoming public meetings, and South Magnolia CSO Control Project Timeline (PDF), updated May 2013.