Modeling groundwater geochemistry in a disposal site of solid waste

Among the potential sources of groundwater pollution are the waste disposal sites that do not meet the operating characteristics to reduce its negative impact. One of these not controlled sites is the Vado Carranza dump, located in the Mexicali Valley, B. C. in northwestern Mexico, which has been in operation for fifteen years and receives about 30 Mg/day of solid wastes. The operation characteristics of this site, including open disposal and burning of wastes and the shallow aquifer in the area, make the soil and groundwater vulnerable to suffer contamination processes. In this research, a geochemical modeling of groundwater was conducted using PHREEQC. The purpose of these simulations was to estimate the geochemical evolution of groundwater in the area of the landfill based on its flow direction and the physical and chemical results obtained from a piezometric network. The modeling results suggest as important processes the following: water evaporation, cation exchange and adsorption of metals coming from the landfill.