Hydrogeochemistry and Groundwater Quality in a Developing Urban Environment of a Semi-Arid Region, Guntur, Andhra Pradesh

This paper describes the results of hydrogeochemistry and groundwater quality to generate baseline information on groundwater resources in the developing urban area of Guntur, Andhra Pradesh. The area falls under a semi-arid type of climate and consists of charnockites and alluvium. Groundwaters are mostly brackish type, having Na⁺:Cl^--facies, that are of meteoric origin. The waters are subjected to evaporation/evapotranspiration process under climatic influence aided by gentle slope, intensively irrigated lands and continued re-use and re-cycling of waters. This process tends to remove ions from the waters for formation of new clay minerals and precipitation of CaCO₃.The soils in the area appear to have the ability to pick up these ionic species during the pre-monsoon season. In the subsequent post-monsoon period, the waters become more saline, which suggests that the ions are leachzd from soils by the infiltrating recharge waters and are added to the groundwater body. In accordance with the domestic and industrial water quality standards, these groundwaters are not safe. The urban authorities of the area, therefore, should take necessary ameliorative steps to overcome the adverse effects caused by the inferior quality of groundwater.