Use of Environmental Isotopic Proxies for Evaluating Geo-Hydrologic and Pollution Aspects of Groundwater on Bangalore City, India

Water quality data from 81 samples sites (groundwater, surface water and sewage) before and after the monsoonal cycles, aquifer characteristics of Bangalore city were compared to assess the risk of urban development in hydrological environment. Isotopic and physicochemical investigations were carried out to characterize isotopic nature of sewerage and their influence on groundwater in the crystalline aquifer. The similarity of water quality data was assessed using PCA analysis and samples were differentiated as strong to moderate sewerage or geogenic influences. They were compared with the isotopic signature and discriminated as under the control of different sources. From the tritium measurement, it is inferred that groundwater is recharged within 50 years. 14C values is 56 pmC (~ 4407 years), indicative of a complex aquifer system in this urban area. Study evaluated the possibilities of isotopic signature for the study of geo-hydrologic and pollution aspects of groundwater in an urban set up