Groundwater flow and solute transport in the industrial well fields of the Texcoco saline aquifer system near Mexico City

Abstract

The two thin aquifers under production in this area are bounded by highly compressible aquitards which supply tremendous volumes of water to the aquifers through leakage. A quasi three-dimensional integrodifferential equation scheme is used for the flow modelling. The solute mass transport model is based on the method of characteristics combined with a particle tracking scheme. The models are accurately calibrated to piezometric field measurements and concentration distribution data from the production wells. Piezometric nests installed in the surficial clay aquitard indicate that in the heavily pumped areas, infiltrating rainfall is diluting the pore water concentrations in the aquitard which may account for declining concentrations in the production wells which have been recently observed. Analysis of the field data also indicates that the surficial aquitard is fractured and that the fracture network may play an important role in the movement of solutes in the aquitard. -from Authors