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The Central Arizona Project aqueduct diverts water from the Colorado River into central and southern Arizona. The CAP is the largest and most expensive aqueduct ever constructed in the United States. The pumping station draws about 1.6 million acre-feet of water each year from the Colorado River via six pumps, lifts water 900 feet vertically through two twelve-foot diameter steel pipes, each 2,500 feet long, to the Buckskin Mountain Tunnel. The scope of work for this project consisted of removing an existing hot applied coal tar enamel with ultra-high pressure water jetting. Following removal, surfaces were abrasive blasted to SSPC SP-10 near-white metal degree of cleanliness followed by the relining of the discharge line and manifold. The slopes varied from 30° to a 45° incline.   Two phases were included in this work. The first phase was a collaborated design and build with CAP which included review of the project designs and specs and recommendations for change. Several changes were permitted, presented by Hartman Walsh, that made the project more economical and shorter in duration for the owners' benefit. The second phase was the actual construction. Challenges that were faced during the project included the extreme Arizona heat during the hottest month of the year, where temperatures would often reach up to 120° F, and site access, which was a dirt road up the side of a mountain. Quality control was conducted throughout the project to ensure the coating will last for 25-30 years making this project a success that completed a week ahead of schedule.

"Hartman Walsh was superb with delivering a quality finish to our biggest project of the year. The Hartman Walsh team worked every day to make sure CAP was happy with all steps within the project and truly showed how professional they are within the industrial coatings industry. We as the owner couldn't have asked for more, and with the difficulties and dynamics of our system we are pleased with the results."


Tommy Barnes, Engineer Construction Inspector

Central Arizona Project

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