Water Quality is different from every source. Surface water contains higher load of suspended solids, organic and colloidal matter but low on dissolved solids. Surface water sources are river, creek, pond, lake and the largest – the sea. Sea water is not used frequently due to its high salt content except for special cooling needs like sea water cooling systems. The other source is the ground water. Ground water is usually of constant quality and temperature, free of suspended solids due to the filtering effect of soil through which it passes. But contains more dissolved solids along with Fe and Mn in some sources. Uses: Quantitatively water is used for industrial applications either for cooling system, steam generation, process water and for general flushing, cleaning and drinking purposes. With these many applications the criteria for allowable impurities in water are set depending on the water quality requirement.. Impurities harmful effect: The harmful effects may be classified as deposits or scales formed in boilers and other heat exchange equipment, poor quality of steam, corrosion of boiler, heater, heat exchangers, storage tanks and pipelines. For textiles and food industry, the discoloration, flavor and taste is mostly affected. For drinking and potable water suspended impurities will result in contamination and taste.