Wastewater (Sewer) Operations

The District is in the wastewater collection business, not the treatment business. Through a complex system of pipes and lift stations over challenging hills and topography, all wastewater from the District's system is conveyed to the King County Wastewater Treatment system, located in the south end of the District. King County then conveys the wastewater to the Renton South Treatment Plant for treatment and disposal.

When it comes to managing wastewater, protecting public health is paramount. The goal of wastewater operations is to provide uninterrupted sanitary sewer conveyance and mitigate overflows into streams, lakes, and private property. That’s what keeps us on the leading edge of technology, system management, long-range maintenance, fiscal and environmental stewardship. 
Cool facts about your sewer system.

  • 173 miles of sewer main
  • 20 lift stations (to move wastewater up hills)
  • 1 regional sewer connection
  • Conveys an average of 1.8 million gallons per day or 660 million gallons of wastewater per year, in a reliable and cost effective manner with no adverse compliance or environmental issues.

Maintaining the absolute reliability of your sewer service means maintaining every working part of the system to ensure an uninterrupted conveyance of wastewater flow. Sewer operations staff provides the maintenance support, technical knowledge and expertise to achieve this goal. Wastewater operations ensures a 24-hour reliable service to all sewer customers.