
When many people think of a water source, they think of lakes, rivers and streams; in other words, surface water. However, of all of the usable freshwater in the world, approximately 97 percent of it is groundwater. The problems of water quality have become more important than the quantity, as the environmental problems are getting more serious in different parts of the world. A number of factors like geology, soil, effluents, sewage disposal and other environmental conditions in which the water happens to stay or move and interact with ground and biological characteristics. This study is made to evaluate the status of ground water quality and its suitability to irrigated agriculture. Characterization of physio-chemical parameters of groundwater from 11 different locations nearby the small scale industries and rice mills in and around Thanjavur town have been carried out. Water quality data used in the analysis include Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Hardness (TH) and Sodium Adsorption Ratio (SAR). Na-Ca-Mg water types are dominant in the study area.