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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

More Contact Info

Project Overview

Environmental Services is nearing completion of construction on a project to help keep stormwater and groundwater out of sanitary sewers in Southwest Portland. Inflow of stormwater and of groundwater into sewer pipes occurs when storm drains are directly connected to the sanitary sewer or because cracks in sanitary sewer pipes allows groundwater to flow into the public sewer main. This is known as "inflow and infiltration" and can overload the sewer system and cause sewer mains to overflow at low points and drain into ditches or nearby waterways.

The Middle Hillsdale Inflow and Infiltration Pilot Project will help keep stormwater and groundwater out of the sanitary sewer system by repairing sewer laterals that connect houses and properties to the sewer main.


Work will occur on streets identified with bold red lines on the map below:

  • Some work will occur in the public right-of-way in streets, at curbs, and in planting strips.
  • Some work will occur on private properties. Work on private properties is being coordinated directly with participating property owners.

Project map


Construction began in the summer of 2018 and is anticipated to continue through April 2019. 

Work Hours

Standard City of Portland construction hours are 7 a.m. to 6 p.m. Monday through Friday. There may be work during the same hours on Saturday if needed.

What to Expect During Construction

Traffic Delays: You should expect traffic delays in and near the work area. Please observe traffic control devices and signs, and follow the directions of flaggers.

Local Access: Local access to all properties will be maintained, but construction activities may impact or delay normal use of your driveway.

Parking Restrictions: On-street parking will be restricted in and near the work zones to create a safe work environment and to stage equipment and materials.

Equipment Storage: Some equipment and materials may be stored overnight on your street, nearby streets, or other public right-of-way areas.

Maintained Service: Water and other utilities will remain in service during construction, but sewer service may be impacted for short periods.

Sewer Service Interruptions: At times, you may be required to stop the discharge of sewage and wastewater for short periods of time while your sewer line and lateral are being constructed. This will require that you not use any water, flush toilets, shower, launder clothes, or run the dishwasher. These periods will last from morning until late afternoon. We will let you know when these sewer service interruptions will occur.

Noise, Vibration, and Dust: Construction creates noise, vibration, and dust, but minimal disruption to neighborhood activity is expected in this project.

Site Restoration: The contractor will restore your site as soon as possible after construction; however, some temporary restoration may be necessary until the weather is more conducive for final restoration of paving, curbs, sidewalks, and driveways. Dry weather will enable us to provide the best quality paving and concrete work.

City Inspector On-site: A city inspector will be on-site during work hours and may be able to assist you with an immediate need during construction.

Construction Methods

The city’s contractor used a combination of open trench and trenchless methods to replace sewer service laterals on private property.

Because of higher than anticipated groundwater levels in the central and southern sections of the project area, the city's contractor had to switch construction methods from Cured-in-Place-Pipe Lining to Pipe Bursting. While pipe bursting is still a trenchless method, it is more disruptive. In addition, some digging was necessary to repair major sags in sewer pipes. Click here for more information about the construction methods used in this project, including Cured-in-Place-Pipe Lining, Pipe Bursting, and Open Trench Excavation.  

As the contractor moved from property to property, they assessed conditions and determined the best approach for replacing the sewer service laterals.