GEOCHEMICAL PROFILES OF GROUNDWATER IN THE YUCATAN PENINSULA, MEXICO

For some time now, Mexico’s quality of fresh water throughout the Yucatan Peninsula has been diminishing due to many factors. The karst geology, increase of the population and inadequate disposal of wastewater are all key components leading to the unsafe drinking water. The goal of our investigation was to determine the extent of pollution in groundwater of the Yucatan Peninsula. During July 2009, the groundwater was tested at several locations through the Yucatan Peninsula which included Tulum, Xcalak, Ucil, Aktun Chen, and Calica. The sampling included a series of cenotes (sinkholes) throughout the peninsula that range from protected to impacted by the population growth. Data was collected using the Datasonde 5 and included depth, pH, specific conductivity, dissolved oxygen, temperature and oxidation reduction potential. The geochemical profiles in Xcalak, Ucil and Calica indicated the depth to the freshwater/salt water interface which range from 13m to 68m below the water surface which increased further from the coast. The redox conditions indicated that the water that was highly impacted by organic matter were highly reducing (Xcalak, Ucil, and Calica) while water that was protected (Aktun Chen and Tulum) were aerobic. The goal of this research is also to have a better understanding of the environmental impact of waste disposal and inform policy-makers about the effects of injection of sewage into groundwater systems and about the treatment of wastewater.