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The image shows a project banner with the text “South Interceptor Rehabilitation Project” alongside a photo of stacked concrete pipes and the King County Wastewater Treatment logo.

South Interceptor Rehabilitation Project

The South Interceptor Rehabilitation project will repair over 1,600 feet of deteriorated sewer pipe and seven maintenance holes in the City of Renton.

 

Project description

King County will repair about one-third mile of sewer pipes and seven maintenance holes serving the City of Renton. Work is expected to start in Spring 2028.

These pipes are old. Repairing them will maintain reliable service for decades. We will use temporary pipes to maintain sewer service in your area while we make repairs.

Project update

October 13, 2026

Survey and soil sampling work starting October 19

Night work and lane closures

Starting as early as Monday, October 19, crews will begin surveying the area to locate underground utilities and collecting soil samples. Crews expect to complete the work within three weeks. Learn more about this work here.

Past project updates

Project location

The pipe runs deep underground beneath SW Grady Way and Interstate 405. The project will occur in a commercial and industrial area in Renton with a lot of traffic. We will work with the City of Renton to keep traffic moving and limit disruptions.