Water is an essential component for the survival of life on earth, which contains minerals important for humans, plants and aquatic life. Water, a prime natural resource and precious national asset, forms the chief constituent of the ecosystem.Water is a universal solvent and the most plentiful substance on earth. About 2% of the planet's water is fresh, but 1.6 % is locked up in polar ice caps and glaciers. Another 0.36% is found underground in aquifers and wells. Therefore, only about 0.036% of the planet's total water supply is accessible in lakes and rivers. A growing number of contaminants are entering water supplies from industrialization and human activity. Any physical, chemical or biological change in the water quality that adversely affects the living organisms or makes water unsuitable for desired uses is water pollution.