Groundwater quality impact assessment on lekkur sub basin using hych program: a case study from tamil nadu, india

A detailed hydrogeochemical study was carried out in Lekkur sub basin which is part of Vellar basin. Groundwater is the major source of water supply for agricultural and domestic uses. The agricultural and urbanization activities have made a lot of impact on groundwater quality of the study area. In order to understand the groundwater quality variations in the sub basin area, twenty groundwater samples were collected from dug wells and hand pumps during pre-monsoon season. These water samples were analysed for major cations and anions. The water analysis data were processed using a computer program HYCH. In this program, numerical steps are adopted for the hydrochemical facies classification using the criteria of Handa, Piper, Stuyfzand and USSL schemes. The results show that according to Stuyfzand classification, 50 % of water samples are oligohaline to fresh type. Based on USSL classification, 40 % of water samples fall in good to moderate (C2S1 and C3S1) categories and the rest of the samples exhibit poor quality. This shows serious problems for domestic and agricultural uses during pre-monsoon period.