Like the Agua Nueva facility that won the Best Project award in this category, the Tres Rios Water Treatment Plant improvements and upgrades are also part of Pima County's $720-million Regional Optimization Plan. Tres Rios expanded the plant's capacity to 50 million gallons per day from 37.5 mgpd. Close collaboration between the construction team and plant operations staff was integral in managing more than 150 process tie-ins and three plant shutdowns.
"The plant was 40 years old when we got there so there were a lot of unknown conditions," says Duane Frerker, project manager with MWH Constructors. "But the team we had out there handled it very well."