Soos Creek Sewer Improvements

The sewer improvements will help meet the growing demand for sewer service in Covington, Maple Valley and
Black Diamond.

Map of phased capital improvements in southeast King County, 2005-2020

What's New

Siting Facilities for Future Planned Growth

In 2002, King County signed an agreement with the Soos Creek Water and Sewer District, committing itself to build and operate three regional pump stations and 10 miles of sewer lines to meet the long-term needs of this rapidly growing area.

Working with local jurisdictions and interested citizens over a 10-month period, King County’s project team identified a preferred location for Pump Station D (now referred to as the Covington Pump Station) and completed predesign work on it and on the sewer route.

Phasing Plan Revised due to High Project Costs

Near term—by 2010

When the estimated cost of the Covington Pump Station and pipeline turned out to be significantly higher than anticipated, the county explored alternative options for phasing the system improvements. This analysis determined that the most critical short-term capacity need is in Black Diamond. The County’s revised plan will address that need by constructing a wastewater storage facility in Black Diamond by 2010. Planning for this facility will get underway in 2006.

Longer-term—by 2020

The county plans to build additional regional pump stations and pipelines between Black Diamond and Kent by the year 2020. To ensure that these facilities will be in place when needed, the County will continue to work with Soos Creek Water and Sewer District and monitor system flows.

The map indicates the approximate timing and locations of the new facilities that will serve southeast King County by 2020. The location of the connection to the county’s existing sewer, at Southeast 277th Street in Kent, is also shown. The predesign work and public input that were invested in siting the Covington Pump Station and pipeline in Kent and Covington will remain relevant and useful when the longer-term project again moves ahead. We thank those of you who participated in the project.