Groundwater Quality Evaluation in Salem District, Tamil Nadu, Based on Water Quality Index

Groundwater is considered a vital natural resource due to its significant use for drinking, irrigation and industrial purposes. Groundwater has been a big variant in quality and quantity with respect to time and space. So the quality of groundwater has been assessed in Salem district. A detailed study was made in the study area for the quality of groundwater for drinking in premonsoon and postmonsoon based on the Water Quality Index (WQI). Groundwater samples were collected in sixty six locations in both premonsoon and postmonsoon in the year 2007. Various physicochemical tests were carried out and WQI was calculated based on pH, turbidity, total dissolved solids, total alkalinity, total hardness, nitrate, chloride, calcium, magnesium, iron and fluoride. The comparison between the premonsoon and postmonsoon reveals that in premonsoon season 56.06 %, and in postmonsoon 65.15% of the water samples were fit for drinking. The groundwater quality was found to be unfit for drinking in 22.72% of the samples in premonsoon and 18.18% of the samples in postmonsoon.