The suitability of groundwater for drinking purpose with respect to BIS: The samples are collected the period from 1981-2011. The suitability of ground water resources available in the country are also not uniformly distributed and the changing land use pattern and population growth and resulting water resources development has resulted in stress in the environment. The result shows the groundwater has partial suitability for drinking purposes and public health because of the concentration of TDS, EC, Mg and Na in groundwater. They have concentration than the recommended limits for drinking. They have partial suitability for domestic use for Human consumption. The parameter such as SAR, Na % is estimated were the one all locatle to assess. These parameter concern suitability of water for irrigation purpose. The EC and sodium concentration are very important in classifying irrigation water. The salt present in the water, besides affecting the growth of the plants directly affect the soil structure, permeability and aeration, which indirectly affect the plant growth. Considering the seriousness of the groundwater contamination and groundwater quality along the study area (Koraiyar sub watershed) has been done.