Chemical quality of water in relation to water use and basin characteristics, Tucson Basin, Arizona

Abstract

The areal distribution of the chemical quality of the Tucson basin ground water has been mapped. The basin was divided into five study sections, according to the relative concentrations of the chemical ions studied, The five chemical quality sections are as follows: 1. Canada del Oro; Catalina, Tanque Verde, and Rincon Mountain foothills and extension into the northeast half of the basin low concentrations except for Tanque Verde anomaly. 2. Tucson-Benson Highway area extending from east of Vail northwest to the Santa Cruz Rivermoderately high concentrations. 3. Foothills of the Santa Rita and Sierrita Mountains extending to the Santa Cruz bottom land moderate concentrations. 4. The Santa Cruz bottom land from Arivaca to Rillito moderately high to high concentrations. 5. The Tucson Mountain foothills extending to the Santa Cruz bottom land low - moderate to moderately high cone entrations0 The water quality of these sections is correlated to the geology of the basin, according to the principles set forth in the section on the "Geochemistry of Ground Water." The effects of man's lowering of the water table are not as yet evidenced in the chemistry of the ground water In conclusion, the part of the Rillito Creek drainage basin in the northeast Tucson basin fill is found to have both the best water quality and the highest specific capacities of the entire basin. Subsurface storage and impermeable boundary limitations may restrict further development of this area, however. Artificial recharge into this aquifer, from Rillito Creek, could alleviate the quantity problems.