Wastewater services

Do business with the Wastewater Treatment Division
Make a capacity charge payment
Get approval for an industrial waste discharge
Coordinate with Local Public Agency (LPA) Program
Become a WTD consultant or contractor
Obtain a septage disposal permit
Locate sewer pipes and other utilities

Duwamish Waterway
Cleaning up and preventing pollution

Working in our community
Equity and Social Justice initiative
Relocation services
Metropolitan Water Pollution Abatement Advisory Committee

Planning for the future
Sustainability
Clean Water Plan - join the conversation
Regional Wastewater Services Plan
Protecting Our Waters (CSO control)
Treatment planning
Conveyance system improvement
Infiltration and inflow control
Sediment management

Seattle
Georgetown Wet Weather Treatment Station
Interbay sewer and odor control upgrade
Ship Canal water quality (joint project with Seattle Public Utilities)
Thornton Creek – Basin sewer study and upgrade
West Duwamish Wet Weather Storage Facility
West Point Treatment Plant improvements

Recently completed projects
List of completed projects

Contact
Our staff
Local sewer agencies
Directions to our offices and facilities

Brightwater Treatment Plant

South Treatment Plant

West Point Treatment Plant

Carnation Treatment Plant

Vashon Treatment Plant

Wastewater treatment process

Serving the region since 1956

In 1956, a group of local residents became concerned about the effect of rapid urban growth, especially the decline of water quality in Lake Washington and Puget Sound. Their activism and advocacy led to the formation of a wastewater treatment utility to serve the region.

Today, King County Wastewater Treatment Division provides services to 18 cities, 15 local sewer districts, the Muckleshoot Indian Tribe, and more than 1.9 million residents across a 420-square-mile area in King, Snohomish, and Pierce counties. Learn more about our history.