Transmission Main Assessment Phase 3

Project Owner: Town of Gilbert
Project Type: Construction Manager at Risk
Construction Dates: 09/24 to 06/26

The Phase 3 (Zone 2 and 3) transmission main (30” to 36”) is a 9.4 mile segment of critical infrastructure in need of assessments and improvements to extend its operational life cycle expectancy. These efforts will include the replacement of in-line butterfly valves and air relief and/or vacuum relief valves and the construction of access manways to improve operational flexibility. We may also replace segments of pipe. Work will be done mainly on Higley Road from Guadalupe Road to Ocotillo Road through an area comprised of residential communities, farmland, schools, churches, and businesses.

There will be four separate “reaches” (roughly two-mile segments) to inspect and rehabilitate during shutdowns throughout the contract. We will utilize strategic scheduling opportunities such as spring break for Williams Field High School to avoid disruption. In preparation, we installed a new 8” DIP water line throughout residential areas. This will make sure local homeowners don’t lose water access.

We will assess the pipes with an Insight Water Technologies leak detection device called a Free-Swimming Multi-Sensor Sphere. It operates within water flows while the main is in service. This device will be inserted at the water treatment plants on each side of the nine-mile alignment, and then retrieved at a fire hydrant near the middle of the pipe length. It will identify areas that need attention as a less invasive alternative to digging up the pipes.