Carolina Trunk Sewer Project

Sewer and Stormwater
Environmental Services is designing a project to repair a section of large concrete sewer pipe running from Barbur Boulevard under Interstate 5 to Macadam Avenue. The "Carolina Trunk" sewer pipe was built almost 90 years ago and is in need of repair to prevent sewer and stormwater overflows.
Construction is expected to start in the 2025 and should take about two years to complete.

The Carolina Trunk is a large sewer pipe that is showing signs of deterioration and needs to be repaired. These repairs will extend the service life of the trunk by 50 years or more, increase sewer resiliency to earthquake damage, and help protect public health and the community by preventing sewage releases to buildings and streets. 

Project Area

The project area is located in S Portland, between S Barbur Blvd and S Macadam Ave.

A map of the Carolina Trunk project area and proposed work.
Carolina Trunk Sewer Project Area

What's Happening Now

The Carolina Trunk Sewer Repair Project is a complicated project with significant challenges.  The pipe is essentially a 3-4 foot wide tunnel located very deep underground.  The project team is conducting extensive investigations throughout the project area.  These investigations will help the project team identify conditions underground, how the sewer system connects to private properties, how stormwater connects to the pipe and how it flows over-ground, as well as the potential impacts to local residents of different construction methods and approaches.

Currently, the team is working to identify the best way forward: rehabilitating the existing pipe so that it carries stormwater only, and then building a new sewer pipe, or abandoning the old pipe and building a new combined pipe along a new route underground.  When we have better information about possible solutions, the project team will reach out to property owners, businesses, and residents in the area to discuss the best path forward.

Crews will be in the area to perform investigative activities. Activities include marking the location of sewer pipes and underground utilities with temporary paint, surveying the land, and collecting soil samples.

We Want To Hear From You

We would like to hear from you about special events, school activities, and community services in your neighborhood you think may be impacted by this project. Also, we want to know if you have any concerns related to business operations, disability or mobility issues, medical or business deliveries, and proposed night work. Your input will help us minimize the impact to your neighborhood during construction.  

Call 503-823-2827, or email

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