Welded Steel Rescues Distressed PCCP in San Diego Pipeline 4 Repair

Construction workers excavating pipe>

Date

04/27/2022

Categories

Northwest Pipe Supplies Custom Fittings for Urgent Rehab Project Identified by San Diego County Water Authority’s Asset Management Program

Utilizing real-time acoustic fiber-optic monitoring, the San Diego County Water Authority detected potential pipeline weaknesses in a 48 LF stretch of 90-inch pre-stressed concrete cylinder pipe (PCCP) along Pipeline 4, a key conduit in the region’s water supply network. The pipeline moves tens of millions of gallons a day from Metropolitan Water District facilities to communities across San Diego County, so quickly executing emergency repairs was essential to avoid critical infrastructure failure and an unplanned shutdown.

The San Diego County Water Authority and contractor JF Shea Construction, Inc. turned to Northwest Pipe Company to produce reliable welded steel fittings to replace the weak sections of PCCP where wire breaks had been detected.

Replacement steel pipe with fittings fabricated by Northwest Pipe Company.
Replacement steel pipe with fittings fabricated by Northwest Pipe Company.

Our team worked expeditiously to fabricate custom fittings from 94-inch steel pipe shipped from the Water Authority to our manufacturing plant in Adelanto, California. Just two weeks from receiving the initial request, Northwest Pipe delivered the completed pieces ready for installation.

Crews from JF Shea worked within a 10-day planned shutdown period to complete all aspects of project construction, which included:

  • Excavating a 55-foot by 20-foot access area.
  • Removing the broken PCCP sections.
  • Installing the replacement steel pipe fittings.
  • Pouring 14 truckloads of concrete encasement.
  • Resetting a blowoff valve removed for pipeline access.
  • Backfilling the excavation site.

Despite the tight timeline, thanks to careful coordination by the Water Authority, and quick action by all involved, the project was successfully completed on time and the pipeline returned to service according to schedule. See more project photos and details, and learn how the San Diego County Water Authority’s Asset Management Program is proactively saving ratepayers money: https://bit.ly/3LiywB7

Clockwise from top right: excavation of PCCP pipeline; installation of new steel pipe included rebar for concrete encasement; crews doing a final walkthrough of the replacement pipe.
Clockwise from top right: excavation of PCCP pipeline; installation of new steel pipe included rebar for concrete encasement; crews doing a final walkthrough of the replacement pipe.