24th Street Water Treatment Plant Rehabilitation

Phoenix, Arizona

The 24th Street Water Treatment Plant (WTP) was originally constructed in the 1950s and had received assorted upgrades in the decades that followed. However, with the plant more than 60 years old, a condition assessment showed that various treatment systems at the plant were deteriorating due to age and use, meaning rehabilitation or replacement was needed.

The City of Phoenix Water Services Department selected Kiewit to deliver the $21 million rehabilitation project at the 140-million-gallons-per-day WTP. Kiewit served as the Construction Manager at Risk and self-performed approximately 50 percent of the work.

The Kiewit team rehabilitated the flocculation and sedimentation basins, filter valves, raw water inlet pipe, main switchgear and other electrical equipment. The team also performed the inspection of the sludge blowdown pipeline and oversaw the relining of the pipe. In addition, the project team replaced the chlorine scrubber and the slide gates/valves at the filter drain gate and also implemented new magnetic flow meters.

Kiewit provided cost modeling, scheduling, constructability reviews, value engineering and project phasing analysis at 30%, 60% and 90% design.

Much of the work was performed during a three-month shutdown of the plant, and the remainder of the effort was completed while the plant remained fully operational. This required close coordination, including through weekly meetings and detailed schedule review, with plant staff.

Kiewit helped expedite delivery of long-lead items through detailed planning and issuance of early procurement packages. Through value engineering, the Kiewit team identified $100,000 in savings for the city. Kiewit also helped to expedite reviews with the chlorine scrubber supplier, and field inspectors from the Kiewit Supply Network visited the vendor’s multiple fabrication locations to help drive quality.