The Palm Valley Water Reclamation Facility (PVWRF) treats 2.5 million gallons of wastewater per day (MGD). Originally constructed in 2002 and expanded in 2013 and again in 2017, the facility needed rehabilitation of the concrete equalization tank to maintain structural integrity and extend service life.
Work on the plant began in July with the first steps of bypassing the lift station and the Equalization (EQ) tank. Next, the tank needed to be drained and cleared of the sludge/sediment. The amount of sediment in the tank was three to four times more than anticipated, and in some areas, was up to five feet deep. There was also a significant amount of concrete aggregate, rebar, and debris in the tank from the old, corroded deck.
Once the tank was clear, the rehabilitation work began with hydro-blasting the surface of columns, beams, and walls of the EQ tank. Concrete was repaired per structural engineering designs and surfaces were covered with a corrosion-resistant coating, followed by spark and thickness testing of the coating. Pipes from the grit vortex chambers were then extended below water level to mitigate gas production, which can cause corrosion. This simple step will help to extend the life of the tank.
Liberty and its contractor were able to complete the work and put the facility back into service before the heavier fall wastewater flows, thereby maintaining safe, reliable wastewater service for the greater Litchfield Park and Goodyear areas.