Capital improvement projects

Workers inside tunnel section of the effluent pipe, Brightwater Treatment System. View more photos.

This year King County is committing $232 million to upgrade aging facilities, add capacity to accommodate population growth, address historically contaminated sediments and improve water quality by reducing combined sewer overflows. Specific projects are included in the list below.

King County is carrying out these projects as part of the Regional Wastewater Services Plan, a 30-year comprehensive plan adopted by the King County Council in 1999 to ensure the regional sewer system keeps pace with growth and continues meeting regulatory requirements.