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Wastewater Treatment

King County, Washington

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King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-477-5371
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

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Staff Contacts

Sunset and Heathfield Pump Stations and Force Main Upgrade Project

Project design

July 19, 2016 -- How King County’s new sewer pipeline will be installed in Southeast Bellevue

King County’s contractor will install a new sewer pipeline in Bellevue. King County will upgrade this area of the regional wastewater system to provide additional capacity for the area’s growing population. The current 12 inch sewer force main pipe will be replaced with a 24 inch pipe to increase capacity.

Two main construction methods will be used to install the new force main pipe.

  1. Open-trench construction will be used for a portion of the installation.
  2. A trenchless method (Horizontal Directional Drilling, or HDD) will be used to avoid surface impacts in critical areas, from Sunset Pump Station near Vasa Park to 166th Avenue S.E. Learn more (pdf).

Project description

The Sunset and Heathfield Pump Stations and related sewer pipes send sewage from Sammamish, Issaquah, and Bellevue to be cleaned at King County’s treatment plant in Renton. This sewer system has provided reliable service for 50 years and is reaching its limit.

This project will upgrade both pump stations and the connected force main pipe. The project will also upgrade the Eastgate Trunk structure near I-90. The Eastgate Trunk connects the force main pipe to a larger pipe, carrying flows to be cleaned. The improved system will help serve the growing population for many years.

Sunset Pump Station upgrades 

  • 4 new pumps to increase capacity
  • New electrical and controls systems
  • New standby generator
  • New heating and air conditioning systems (HVAC)
  • Landscaping
  • Roof replacement
  • New lighting and fencing

Heathfield Pump Station upgrades

  • New lighting and fencing
  • 4 new pumps to increase capacity
  • New electrical and controls systems
  • New standby generator
  • New heating and air conditioning systems (HVAC)
  • Rain garden
  • Landscaping
  • Roof replacement  

Project area

Project area
Heathfield Pump Station, Bellevue
Heathfield Pump Station,
3541 - 163rd Ave. SE, Bellevue
Sunset Pump Station, Bellevue
Sunset Pump Station,
3730 W. Lake Sammamish Pkwy. SE, Bellevue

Project schedule

The project team has finished the first design phase. The basic design for the pump stations has been determined. This includes the general layout of pump station equipment. The basic route and construction methods of the new force main pipe have also been decided.

Over the next two years the project team will continue designing the pump stations and force main pipe upgrades. Preliminary design was completed in February 2015. The team will complete final design by the end of 2016. Construction is expected to begin in 2017 and end in 2020.

Project schedule

Envision

King County works to build and operate facilities that benefit the local community, environment, and economy on all our projects. The good news is King County can now earn a certificate for these efforts. The Envision program provides a framework to help measure how well an organization incorporates sustainability on infrastructure projects.

Envision is similar to LEED.

For more information

Related information