Evaluation of the effectiveness of hydrogen and oxygen isotopes used in concert with chemical water-quality parameters as indicators of subsurface water movement and source

A multiuse area, 15 miles south of Tucson, Arizona, was selected to test a water-pollution source assessment technique emphasizing the combined study of stable isotopes of water, major anions and cations, trace elements, pH, specific conductance, and water temperature. Computer-based analytical techniques were developed to identify data patterns indicating effects of recharge sources. The range in isotopic ratios along the study transect suggested that tracing surface-water recharge by its isotopic signature is possible, if density and frequency of sampling are sufficient. At some sites, water quality parameters were found to exceed state drinking-water supply standards. High sulfate concentrations were found in the surface water of mine pits and tailings ponds