Environmental Services is designing a project in Willamette Heights to reconstruct about 4,800 feet of public sewer pipes. The project will also construct, repair, or replace 36 manholes, 15 storm drain inlets, and 96 service laterals that connect private properties to the public sewer. These improvements will relieve basement sewer backups at 31 properties and increase the capacity of the 100-year-old sewer system to handle combined sewage and stormwater.
Project design will continue into the summer of 2019, followed by the contractor selection process in the fall. Construction is anticipated to begin in late 2019 or early 2020 and take a year to complete.
The map below illustrates where this project will construct sewer improvements. The primary construction method for each pipe segment is noted.
The purpose of this project is to relieve basement sewer backup risk at 31 properties in the project area. To that end, this project is looking at upsizing or repairing portions of the 100-year-old public sewer main line to increase its capacity to handle combined sewer and stormwater.
Engineers are also exploring ways to reduce rocky debris in stormwater that drains from Forest Park into the combined sewer in NW Thurman Street. This, too, is to help increase the capacity of sewer pipes and reduce basement sewer backup risk.
Designing this project is complex due to several challenging conditions -- multiple soil types, buried trolley tracks, curvature of the street, nearby landslide recovery efforts, location of other utilities, limited parking supply, traffic controls, and the bridge. These and other factors will make reconstructing the sewer system challenging. The soil sampling and compaction tests that we completed in August 2017 helped engineers better understand some of these conditions.
Coordination with Transportation
The Portland Bureau of Transportation (PBOT) is coordinating landslide recovery work on NW Thurman Street. PBOT will not complete their street restoration work in 2019, but Environmental Services will still proceed with sewer construction. The alignment for the new sewer will be designed and constructed to avoid conflict with the PBOT restoration area. For questions about PBOT's landslide recovery work, please contact Geren Shankar at 503-823-4793.
Sewer construction may also require removing buried trolley track rails and ties to install new sewer pipes. After a construction contractor is selected in the fall of 2019, the contractor will propose the removal methods, a sequencing plan for construction activities, and a general schedule.
As is standard with all sewer projects, Environmental Services will coordinate with PBOT on street permits, street restoration requirements, and safe traffic controls. Any pavement disturbed by this project will be restored per PBOT's guidelines.
Because the neighborhood has been through other major construction projects recently, including a bridge replacement in 2014 and a paving project in 2012, we understand that residents may be growing weary of construction activities and traffic controls. Thank you for your patience and cooperation as Environmental Services works to complete this major capital improvement project to provide another 100 years of public sewer service.
For More Information
If you would like more information about the project or have questions and concerns you’d like to discuss, please call or email:
If you have a question about pipe work near you, please include your name, property address, and project name (NW Thurman) in your voicemail and email so we can provide you more details about what to expect in front of your property. Also, please write "NW Thurman" in the subject line of your email. Click SIGN UP to sign up for periodic email updates.