Dibble

Arizona State University (ASU) Waterline Replacements

The City of Tempe owns public water mains throughout the ASU Tempe campus. The existing 8-inch to 12-inch water mains are located within developed corridors on the ASU campus. The City is replacing some of the water mains that are at the end of their useful life, with prioritization based on water main break history.

The water main replacements are being completed in four phases:

• Phase 1 – Approximately 700 linear feet of 8-inch water main along Tyler Mall, from Cady Mall to Palm Walk.
• Phase 2 – Approximately 600 liner feet of 8-inch water main through the Health Service parking lot, from University Drive to Tyler Mall.
• Phase 3 – Approximately 500 linear feet of 12-inch water main along Cady Mall/College Avenue, from Apache Boulevard to Lemon Street.
• Phase 4 – Approximately 850 liner feet of 12-inch water main along Cady Mall, from University Drive to south of Tyler Mall.

Through the City’s on-call, Dibble designed the first two phases of water main replacement in 2020 and 2021. These two phases were constructed in 2021 using job order contractor (JOC) procurement. Dibble CM provided construction management and inspection services for Phases 1 and 2. The Dibble design team stayed involved during construction and was on site regularly to minimize time needed to respond to contractor requests for information (RFIs). The design team anticipated that field changes would be necessary due to the site conditions and amount of existing utilities. We worked closely with the JOC contractor to work through constructability items and provide design solutions quickly.

Phases 1 and 2 were constructed in the middle of campus on a tight timeline between semesters to reduce disruption to students. Dibble CM coordinated with stakeholders – including the City of Tempe, multiple ASU departments, and contractor – to ensure everyone’s needs were met. This included conducting waterline testing with the City; maintaining ambulance access to ASU Health Services while working through their parking lot; maintaining fire watch with ASU Fire and facilities during water shutdowns; and maintaining access through Tyler Mall during construction. We also coordinated with multiple adjacent construction projects that were within the work zone.

Since the campus in the area of Phases 1 and 2 is old, many unknown underground utilities and obstructions needed to be investigated. These unknowns forced us to relocate sections of the waterline to work both vertically and horizontally. Dibble CM worked with the contractor to investigate and research the unknown obstructions to help determine what could be removed and what had to stay in place. We also utilized on-site meetings to work through how best to proceed. We answered questions (RFIs) as quickly as possible to meet the schedule. We also tracked the extra work by the contractor closely to ensure compensation was fair to the contractor and the City.

The Phase 3 waterline replacement is ongoing, and Phase 4 has not yet started.