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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Ave, Suite 613, Portland, OR 97204

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Portsmouth Force Main Valve Vault Monitoring

Updated December 14, 2020

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The City of Portland’s Bureau of Environmental Services is continuing our work to repair and replace critical sewer and stormwater infrastructure. Environmental Services will continue to provide information and updates on construction schedules and activities during the COVID-19 emergency.   

Environmental Services is designing a project to install monitoring equipment along the Portsmouth force main sewer line on Swan Island. The equipment is part of a larger monitoring system that helps to keep public sewer pipes operating efficiently and safely, and will help to prevent sewage overflows to the Willamette River.

Portsmouth Force Main Project MapSchedule

Construction is anticipated to begin in summer 2021 and take about nine months to complete. 

Monitoring Equipment

This project will install equipment at six air pressure relief vaults along the force main (see map) to monitor sewage levels in the vaults and alert maintenance staff of potential problems so that they can take corrective action.

The air pressure relief vaults continually release air during force main operation to protect against unwanted sewage and stormwater surges, maintain system efficiency and safety, and control odors. A problem inside the vaults could cause a sewage overflow to the Willamette River. 


Work crews will install wireless monitors at four locations. All locations will have communication control boxesinstalled aboveground. The six air pressure relief vaults are located at:

  1. Traffic island at 4630 N Basin Avenue (at N Going Street and N Basin Avenue)
  2. Anchor Park parking lot at 3627 N Anchor Street (adjacent to Dr. Martens)
  3. Parking lot at 5567 N Basin Avenue (adjacent to Northwest Paper Box Manufacturer)
  4. Parking lot at 6147 N Basin Avenue (adjacent to Auto Truck Transport USA LLC)
  5. Parking lot at 6335 N Basin Avenue (adjacent to Grainger Industrial Supply)
  6. Northern end of N Basin Avenue adjacent to cul-de-sac at foot of 6759 N Basin Avenue (adjacent to the foot of Waud Bluff Trail and U.S. Coast Guard)

All six wireless installations will not require excavation. Crews will install the wireless communication devices inside the vaults. 

The city will work with adjacent property owners and business operators to explain the project, gather information about how they might be affected and work to minimize construction impacts.

Sign Up for Updates

Before and during construction, we will be sending out periodic email updates to keep you posted on the schedule, possible traffic detours, delays and lane restrictions. We encourage you to sign up now to receive updates by emailing Debbie Caselton with “Portsmouth Force Main” in the subject line.