Memorial Day closure

Most City of Portland offices will be closed Monday, May 27, in observance of Memorial Day.

Pipe Reaming

Pipe Reaming is a trenchless method of sewer construction. It allows for replacing or upsizing an existing pipe without the need for an excavated open trench. It is used to remove underground sewer pipes while simultaneously installing new pipes.

Pipe Reaming is similar to Pipe Bursting. Crews dig a sending pit and a receiving pit to install a new sewer pipe. Crews insert a reaming tool into the existing sewer line. The reaming tool breaks the old pipe apart and pulls the new pipe into place behind it.

The difference between pipe reaming and pipe bursting is that with pipe bursting, the pipe installation process bursts through the old pipe, breaks it up, and pushes the broken pieces out into the surrounding soil. With pipe reaming, the pipe installation process not only breaks up the old pipe but also grinds the broken pieces into smaller fragments. Crews then use a vacuum excavator pump to remove the old pipe fragments through the newly installed pipe. 

Pipe reaming may be preferred to pipe bursting in locations where underground utility lines in close proximity to the sewer pipe could be impacted by the broken pipe pieces, and in locations where buildings and structures in close proximity to the sewer pipe could be impacted by vibration.

The work involves the following steps:

  • Dig small trenches to expose existing lateral connections where adjacent properties are connected to the mainline public sewer.
  • Disconnect existing laterals from the mainline public sewer pipe to be repaired and provide a temporary connection to maintain sewer service.
  • Cover the trenches with steel plates and proceed with the pipe reaming process.
  • Dig a sending and a receiving pit to the required depth.
  • Insert a reaming tool into the sending pit and connect the new sewer pipe to the reaming tool.
  • Pull or push the reaming tool through the existing mainline sewer pipe, breaking it apart, while simultaneously pulling the new sewer pipe in place. The pipe reaming process grinds the broken pieces of the old mainline sewer pipe into smaller fragments.
  • Use a vacuum excavation pump to remove the old pipe fragments through the newly installed pipe.
  • Connect existing laterals to the new mainline sewer pipe.
  • Cover open pits with steel plates—or secure the pits with fencing—at the end of each day as needed while work is in progress.
  • Backfill pits with sand or gravel and apply temporary asphalt patches.
  • Conduct quality control inspections.
  • Complete permanent pavement restoration of patched pits after work passes inspection.