Val Vista Transmission Main rehabilitation

Project Owner: City of Phoenix
Project Type: Construction Manager at Risk
Construction Dates: 10/17 to 02/18 (GMP 1) and 11/18 to 01/19 (GMP 2)

GMP 1 included the rehabilitation of approximately 3,109 LF of 96" transmission main using a welded steel liner. GMP 2 includes the rehabilitation of approximately 4,901 LF of 90" to 96" transmission main using welded steel liner. Work will be done in six different access portal (pit) locations in the City of Mesa. The scope of work for rehabilitation includes the following:

  • Dewatering of the existing transmission main.

  • Excavation and backfill of access portals.

  • Demolition and removal of the existing PCCP transmission main at access portals.

  • Installation of new welded steel liner inside the existing PCCP transmission main.

  • Grout annular space between the inside of the existing transmission main and the outside of the newly installed welded steel liner.

  • Cement mortar lining the interior of the newly installed welded steel liner.

  • Installation of closure piping at the access portal locations.

  • Fill, flush, test, and disinfect the previously dewatered section of transmission main.