AN ASSESSMENT OF WATER QUALITY (NH4+, NO2-, NO3-, TP, SO4, COLIFORM BACTERIA AND HEAVY METALS) OF THE MAIN WATER SUPPLIES IN THE STATE OF CAMPECHE

Abstract

Water quality testing (in situ and in laboratory) was conducted on 50 wells across the state of Campeche. Further to this (to aid in water quality management and policy), a GIS was implemented to i) approximate Zones of Contribution (ZOC) for well recharge which in turn supplies water for main cities in the state and ii) perform predictive land change modeling on these ZOC’s to predict the future effect of non-point source pollution. Due to natural geohydrological conditions, values of TDS, pH, and SO4 exceeded Mexican regulations in roughly one third of the wells. Although most wells do not exceed the permissible limits of nutrients and heavy metals, some wells show worryingly high levels of NO2-, TP, and Pb, indicators of pollution from anthropogenic sources. All wells were contaminated by coliform bacteria. Poor water quality in some of the main water sources in the state is mainly due to the proliferation of open dumps and the lack of sewage infrastructure, as well as the ongoing conversion of vegetated land to agriculture into the ZOC’s. It is shown that unless remedial measures are implemented, human activities will continue to extend into these areas, placing the state’s water supply at even higher risk of contamination.