As and Pb Presence within the Meoqui-Delicias Aquifer, Chihuahua, Mexico

This study aimed to determine the amount of As and Pb in the water in the Meoqui-Delicias’ aquifer and their spatiotemporal dynamics. Twenty-one water sampling points were selected. Seventeen samples were from wells and four were from surface water; two were used for human consumption and the rest for agricultural use. The samples were taken from May 2019 to January 2020 in four sampling events, one for each climatological season of the year. The studied geochemical anomalies seem to be linked to the nature and mechanism of volcanic emplacement. Several samples exhibited high concentrations of arsenic ranging from 1.20 to 156.54 ppb, unlike lead, with low values being the maximum value of 26.32 ppb. These elements (As and Pb) are in the water in Naica, part of the mining district where tons of Au, Ag, Pb, Cu, and Zn were obtained. From a geographical standpoint, it is impossible to establish that these elements are related, even though these elements (As and Pb) are present in the water in Naica, a mining zone where tons of Au and Ag were historically mined.