AWWA MTC64536

The City of Scottsdale's Chaparral Water Treatment Plant recently began operation treating Salt River Project water using an innovative integrated process consisting of coagulation for arsenic removal, direct filtration through submerged ultrafiltration membranes, and granular activated carbon (GAC) contactors for total organic carbon (TOC) and taste and odor causing compound removal. Ancillary processes include plate settlers for wash water recovery and centrifuges for solids removal. The unique process for this new 30 mgd facility was developed through six months of pilot-scale operations which competitively compared four membrane systems as well as ozone and two different types of GAC. Membrane processes were preferred due to the very small site and the highly variable water quality delivered to the plant. The entire facility, including the 5.5 mg buried reservoir, sits on only 11 acres and is constructed to minimize neighborhood impact.