Natural occurrence and controls of arsenic in groundwater in a semiarid basin in the Mexican Altiplano

Abstract The sources, mobility, and controlling processes of arsenic (As) in an aquifer system the Cerritos-Guadalcazar area Central Mexico were investigated. High As concentrations (up to 128 μg/L) groundwater found be associated with both primary sources (rocks tailings) secondary (soil sediments). high otherwise pristine Cerritos shallow granular are result a distant source As-rich sediments eroded from mineralized recharge zone karstic aquifer. An intermediate flow delivers load In addition, identification Na–Cl water type indicates regional flow; however, additional information is needed corroborate this assumption. Local flows Ca–HCO 3 low (<1 dissolved concentrations. Principle axis factor analysis shows distinct groupings different characteristics. sulfate dominates southern aquifer, which explains 30% total variance. arsenic-uranium expressed samples deep dug wells tapping basin sediments. A conceptual model was developed where path shown. Three groups showed negative correlation among deuterium excess Evaporation modeling simulate enrichment that evaporation play important role behavior. This research can provide tool for further studies Sierra Madre Oriental.