The hydrogeology and contamination potential of northwestern Yucatán, Mexico

Abstract

The sole source aquifer for northwestern Yucatan is a thin freshwater lens that floats above denser saline water. The saltwater intrusion has been detected more than 40 km inland. The hydrogeologic setting of this aquifer is a mature karstic system with an extensive network of conduits, caverns and cenotes (sink holes). The hydraulic gradient in the area is very low, Oil the order of 7-10 mm/km, suggesting very high permeabilities. These high permeabilities have resulted in a highly vulnerable aquifer that traditionally receives both domestic and industrial waste. The northwestern section appears to be isolated hydrogeologically from the rest of the peninsula by a zone of exceptionally high permeability (ring of cenotes), which is probably related genetically to the Chicxulub Impact Crater.