Evaluation of Groundwater Chemistry in Vaniyambadi Industrial Area with Special Reference on Irrigation Utility

Abstract

As in many districts in Tamil Nadu, Vellore has a long tradition and culture in agriculture. However, the stress on the existing water resources have reduced the availability and deteriorated the quality of water used in irrigation. Present study attempted to assess the hydro- chemistry in order to evaluate the quality of water used for irrigation in and around Vaniyambadi tannery cluster in the Vellore district. Results show that the groundwater in the study area remains alkaline throughout the year. The dominance of major cations and anions in the groundwater were in the order of Na ? ( Mg 2? ( Ca 2? ( K ? and Cl - ( HCO3 - ( SO4 2- ( CO3 2- respectively. This was in agreement with major water types (Na-Cl) observed in the piper plot. A detailed analysis of the hydrochemical data show that tannery effluent, silicate weathering and ion exchange processes are the major factors influencing hy- drogeochemical characteristics of the groundwater. Results of the chloro-alkaline indices confirmed that reverse ion exchange process is a prominent process controlling Ca 2? and Na 2? ion concentrations in the study area. Sodium percentage, sodium adsorption ratio, residual sodium carbonate, permeability index, magnesium ratio and Kelly index were calculated for the groundwater samples. Excluding the magnesium hazard, other parameters showed that the water quality is permissible for irrigation purposes.