Response of Infiltration Rate to Effluent Water Quality Improvement at the Sweetwater Recharge Facility and Santa Cruz River

Abstract

The Reclaimed Water System allows drinking water to be conserved by reducing the amount of potable water applied to large water-use sites like golf courses and parks. Advancements in effluent infiltration can amplify this conservation by making more reclaimed water available. This study, conducted in Tucson, Arizona, assesses the practicality of nitrogen and phosphorus removal as a method of enhancing effluent infiltration. Infiltration rates in recharge basins RB-001 to RB-008 at the Sweetwater Recharge Facility, as well as reach length and recharge in the effluent dominated Lower Santa Cruz River, were studied before and after the removal of nearly 90 percent of nitrogen and 50 percent of phosphorus species in March, 2014. In general, basin infiltration increased between 30 to 70 percent, the wet reach of the Santa Cruz River decreased dramatically and river recharge increased after the water quality improvement, indicating that water quality improvement does improve effluent infiltration.