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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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Open Trench Excavation

Open Trench Excavation is the traditional method of sewer construction and the most common method for replacing a sewer pipe, especially if the original pipe needs to be upsized. It consists of digging down to and exposing the existing pipe, removing the existing pipe or a section of it, installing a new pipe or a section of new pipe, and then backfilling the trench.

The work includes the following steps:

  • Sawcut pavement and dig trench to install mainline sewer pipe
  • Sawcut pavement and dig trenches from the mainline to the curb to install sewer service laterals that connect properties to the public sewer
  • Install new mainline sewer pipes and laterals
  • Cover open trenches with steel plates at the end of each day as needed while work is in progress
  • Backfill trenches with sand or gravel and apply temporary asphalt patches
  • Conduct quality control inspections
  • Complete permanent pavement restoration of patched trenches after work passes inspections
  • Repair any curb and sidewalk panels damaged during construction 
  • Restore any vegetation disturbed during construction with top soil and grass seed