Skip to main content

Sweyolocken Pump Station upgrade

Completed – Winter 2005

King County's Wastewater Treatment Division has upgraded its Sweyolocken Pump Station to protect public health and water quality.

The Sweyolocken Pump Station, located next to Bellevue Way and the Mercer Slough Nature Park , sends wastewater from Bellevue and Mercer Island to a major wastewater pipeline called the Eastside Interceptor. That pipeline then carries wastewater from all Eastside communities to King County's South Treatment Plant in Renton.

The upgrade included advances in technology, such as odor control facilities and noise reduction design. Other improvements include the following:

  • new pumps and pump drives
  • new pipelines
  • new power supply facilities
  • improved landscaping
  • improved architectural design.

In addition, a new building houses an emergency power generator, and the previous pump station building was replaced.


Construction began in spring 2003 and was completed in February 2005.