Hydrogeochemical Assessment of Groundwater in Neyveli Basin, Cuddalore District, South India

In the light of progressive depletion of groundwater reservoir and water quality deterioration of the Neyveli basin, an investigation on dissolved major constituents in 25 groundwater samples was performed. The main objective was detection of processes for the geochemical assessment throughout the area. Neyveli aquifer is intensively inhabited during the last decenniums, leading to expansion of the residential and agricultural area. Besides semi-aridity, rapid social and economic development stimulates greater demand for water, which is gradually fulfilled by groundwater extraction. Groundwaters of the study area are characterized by the dominance of Na + K over Ca + Mg.HCO3 was found to be the dominant anion followed by Cl and SO4. High positive correlation was obtained among the following ions: Ca–Mg, Cl–Ca,Mg, Na–K, HCO3–H4SiO4, and F–K. The hydrochemical types in the area can be divided into two major groups: the first group includes mixed Ca–Mg–Cl and Ca–Cl types. The second group comprises mixed Ca–Na–HCO3 and Ca–HCO3 types. Most of the groundwater samples are within the permissible limit of WHO standard. Interpretation of data suggests that weathering, ion exchange reactions, and evaporation to some extent are the dominant factors that determine the major ionic composition in the study area

Evaluation of the hydro geochemistry of groundwater using factor analysis in the Cuddalore coastal region, Tamil Nadu, India

181-185The hydrochemical facies and its aerial distribution of groundwater present in the coastal region of the Cuddalore region, Tamilnadu had been examined as a part to map their aerial hydrochemical distribution and attempts to explain the geochemical processes controlling its water quality/facies. In the study area aquifers occur in Quaternary deposit. Ten major ions (Ca⁺, Mg⁺⁺, Na⁺, K⁺, Cl⁻, HCO₃²⁻, H₄SIO₄, F⁻, SO₄ and NO₃⁻) were determined for each of 54 water samples collected in two seasons (pre and post monsoon ). The factor analysis was performed for pre- monsoon and post-monsoon data set. This gives an insight into the source of dissolved ions and the hydro geochemical chemical processes which are responsible for the water quality changes that are occurring here including the intrusion of seawater. The present study elucidates the effectiveness of factor analysis in evaluating hydrochemical processes occurring in the coastal regions which are dominated by agriculture and industrial zones