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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

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Project Overview

Environmental Services has completed this phase of a project to repair 100- to 140-year-old public sewer pipes in SW Yamhill and SW Morrison Streets in downtown Portland that were in deteriorating condition. The sewer pipes were showing signs of cracks, breaks, holes, offset pipe connections, and root and grease obstructions, putting the pipes at risk of structural failure. The repairs will protect the public and the environment by reducing the possibility of sewage releases to buildings and streets.

Project Map

Repairs were made to pipes in SW Yamhill and SW Morrison Streets between SW 1st and SW 13th Avenues, plus a small segment on SW Stark Street at SW 1st Avenue.

Project map


Sewer repairs occurred from March 15 to May 20, 2017, with the most challenging work coordinated with TriMet's MAX improvement project in May. Learn more about TriMet’s project at Coordination between the City and TriMet minimizez disruption to residents, businesses, and visitors to downtown. Construction was all hours and all days (24/7) throughout the project.

Noise Variance

The Portland Noise Office granted Environmental Services a Noise Variance to enable the city's contractors to work all hours and all days (24/7). In some locations, construction needed to take place after 6:00 p.m. and before 7:00 a.m. Crews did as much of the noisier work as possible during the day to minimize the inconveniences of nighttime construction.

During the period of March 15 through April 29, because of the high traffic volumes during the normal workday in this major downtown corridor and MAX trains running close to the work zones, it was necessary to do some of the construction between 1:00 a.m. to 4:00 a.m. when trains weren't running.

During the period of April 30 through May 19, the MAX light rail service was not running on SW Yamhill and SW Morrison. Construction continued 24/7 during this period.

Working both day and night condensed several months of urgent sewer repairs into just nine weeks. Environmental Services asked for this noise variance to take advantage of the brief period when TriMet closed the MAX line for repair, giving city crews a window to safely access sewer pipes under the tracks. The City understands the impacts of late-night work on the community, and appreciated everyone's patience and cooperation.

Construction Method

To repair the main line public sewer in the locations shown on the map, the city employed a process called Cured-in-Place-Pipe Lining (CIPP). Work crews access the sewer from manholes to insert a flexible liner inside the old pipe. Hot water or steam inflates and cures the liner, which gradually hardens to form a rigid, smooth surface that seals cracks and restores the pipe to near-new condition. This less disruptive process is also considerably less noisy than open trench excavation. CIPP will strengthen and reinforce the pipes, making them last for many years.

People who live and work near a CIPP repair project can sometimes smell a chemical odor during the pipe-lining work. The odor is from the chemical styrene, which is in the resin liner installed inside the pipe. The odor dissipates quickly once the installation process is complete. The amount of airborne styrene produced by the lining process is not expected to cause health issues for workers or the public. See for more details about CIPP.

What to Expect during Construction

You can expect the following activities and impacts with this sewer repair project:

  • Construction will be all hours and all days (24/7) throughout the project.
  • Construction creates noise, vibration, and dust and disrupts normal activity.
  • You should expect traffic delays, temporary street closures, lane closures, traffic control signage, and flaggers as needed within the work area.
  • There will be rolling two-block closures along Yamhill and Morrison streets that will last approximately three days each as crews move from manhole to manhole along the corridor to repair the sewer.
  • Local access to all properties on SW Yamhill and SW Morrison Streets will be maintained or provided as needed by flaggers.
  • Partial sidewalk segments per block on SW Yamhill and SW Morrison Streets may be temporarily closed, but access will be maintained to all buildings.
  • Staging areas for materials and construction vehicles will be on most cross streets and will require some lane closures and parking removal.
  • Bypass pumping to maintain sewer service during construction may require temporary cross-street closures with local access provided by flaggers.
  • Where possible, bypass pump lines will be covered by ramps at intersections to enable through traffic, but traffic over the ramps will be slowed by flaggers for safety.
  • On‐street parking will be restricted in and near the work zones to create a safe work environment and to stage equipment and materials.
  • Some equipment and materials may be stored on the street overnight.
  • A city inspector will be on-site during work hours and may be able to assist you with an immediate need during construction.
  • Sewer, water, and other utilities will remain in service during construction.
  • To avoid circling around construction to find parking, the city recommends you use SmartPark garages; those near our construction zone are included on the project map.