The study was conducted over ten villages in Perambalur district, Tamilnadu. It covers more than 60 sq.km, assessing the suitability of ground water quality for drinking purpose through water quality index investigation of the different bore wells. This was done by subjecting the ten bore well waters in the fertile area. For calculating WQI, ten parameters such as pH, TDS, EC, TH, Total alkalinity, Sulphate, Chloride, Nitrate, Calcium and Magnesium have been considered. The study spread over three seasons namely pre monsoon, monsoon and post monsoon.