Impact assessment of urbanisation on groundwater regime in part of coastal South Goa

Abstract

Among several human activities urbanization is one which can adversely affect both surface water as well as groundwater regime. In the present study an attempt has been made to assess the ground water regime in an area extensively urbanized and lies in close proximity to the Sea coast in Goa. One hundred groundwater level monitoring stations were established in an area of 41 km2 and TDS, pH EC and temperatures have been measured in the field in all these wells. Twenty five groundwater samples have been collected for bacterial analysis from the shallow unconfined aquifer in the study area. The bacterial analyses have indicated severe groundwater contaminations by Coliform bacteria. The main reasons for bacterial contamination of shallow groundwater are assessed to be high degree of urbanisation and point disposal of urban liquid wastes and cattle wastes. Studies have indicated that the shallow aquifer is made up of highly permeable sandy loam having very shallow water table conditions and hence is found to be highly vulnerable to contaminations. The lack of sewage collection system has adversely affected the groundwater quality in the area.