Sweyolocken Pump Station upgrade increases capacity, reduces odors and noise

2005 Archived News

The King County Wastewater Treatment Division has finished its $7 million upgrade of the Sweyolocken Pump Station in Bellevue to further protect public health and the environment. The pump station will be able to handle projected wastewater flows from the growing local population during the next 20 years.

Construction began in spring 2003 and ended six months earlier than planned. Originally built in 1965, Sweyolocken is one of the oldest pump stations operated by King County. Before construction, the station could pump 22 million gallons of wastewater per day. It now can pump 26 million gallons per day.

This upgrade includes advances in technology, such as odor control facilities and noise reduction design, that will improve existing conditions. Other improvements include:

• 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. The new generator will ensure reliable operation of the pump station during power outages.

The improvements will not only make the pump station look better, but they will also save money for residents of King County by providing more efficient and modern equipment.

The 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.

In planning the construction project, King County understood the importance of the nearby Mercer Slough Nature Park, one of the most diverse ecosystems in the Puget Sound area. So during construction during the past two years, the county's contractor ensured public access to the park, boat launch and trail.

The Wastewater Treatment Division protects public health and the environment by serving 18 cities, 16 local sewer agencies and more than 1.4 million residents in King, Snohomish and Pierce counties. Formerly called Metro, the regional utility has been preventing water pollution for 40 years.