Effluent recharge to the Upper Santa Cruz River floodplain aquifer, Santa Cruz county, Arizona

摘要

The City of Nogales, Arizona, is in the Santa Cruz Active Management Area and is subjectudto the assured water supply and conservation mandates of the 1980, GroundwaterudManagement Act (State of Arizona, 1980). The primary water supply for both NogalesudArizona, and Nogales, Sonora, (commonly referred to as Ambos Nogales) is groundwaterudpumped from the shallow alluvial aquifers which underlie the Upper Santa Cruz River inudArizona and Mexico, and its tributaries (principally Nogales Wash and Potrero Creek).udNogales, Sonora also obtains water from the Los Alisos Basin, which is south of the SantaudCruz Basin in Mexico (Carruth, 1995).udThe NIWTP provides wastewater treatment for Ambos Nogales, and discharges treatedudwastewater to the Upper Santa Cruz River near the confluence with Nogales Wash andudSonoita Creek. The discharge of effluent creates an intermittent stream from the NIWTPudoutfall for approximately 13 river miles to Tubac, Arizona.udThe conservation mandates of the 1980, Groundwater Management Act (State of Arizona,ud1980) require the City of Nogales, Arizona to prove the existence of a 100-year water supplyudas a condition for future growth. The Act also allows Nogales, Arizona to receive rechargeudcredits for the portion of effluent that recharges the aquifer underlying the Santa Cruz River.udThe recharge credits will be used by the City of Nogales as partial proof of a 100-year waterudsupply (Carruth, 1995).