Today human activities are constantly adding industrial, domestic and agricultural wastes to ground water reservoirs at an alarming rate. Ground water contamination is generally irreversible i.e. once it is contaminated; it is difficult to restore the original water quality of the aquifer. Excessive mineralisation of ground water degrades water quality producing an objectionable taste, odour and excessive hardness. Although the soil mantle through which water passes acts as an adsorbent retaining a large part of colloidal and soluble ions with its cation exchange capacity, but ground water is not completely free from the menace of chronic pollution. ADVERTISEMENTS: We have long believed that ground water in general is quite pure and safe to drink. Therefore, it may be alarming for some people to learn that groundwater infact may easily be polluted by any one of the following sources. Problem of groundwater pollution can be understood by two examples i.e. Love Canal episode (1976-77) and arsenic poisoning in West Bengal (India). In most of the cases the quality of groundwater is good and it can be safely used without any elaborate treatment, because the water before getting stored in the groundwater reservoir, undergoes natural filtration during percolation through the soil pores. Further the groundwater is generally free from suspended impurities and organic matters which are responsible for the development of disease producing bacteria. The groundwater is therefore less likely to be contaminated by bacteria. In some cases depending on the characteristics of the geological formations with which the water comes in contact, the groundwater may contain large amount of dissolved salts, minerals, gases, etc., which may impart different taste, odour, and certain properties such as hardness etc., to the water. However, the quality of groundwater may be considerably deteriorated if it gets polluted. Oceans are the major source of water supply in the world. More than 70% of the earth’s surface is covered by water bodies. Within this vast liquid expanse lie inexhaustible amount of food, mineral, energy, salinity gradients besides coal, oil and gas. Compelled by the impending depletion of land resources, man looks to the sea in a frantic search for more and more resources to meet the increasing demand of population. In this pursuit man is prone to destroy the aquatic environment either by mismanaging or by over exploitation. Man’s activities are largely responsible for measurable and detrimental effects on the aquatic environment. Oil pollution in the sea appears to be the main factor which poses serious threat to the marine ecosystem and fisheries of the world. Now the oil pollution of harbours, bays, rivers, beaches and open oceans has been increasing tremendously every day. Marine pollution is defined as the discharge of waste substances into the sea resulting in harm to living resources, hazards to human health, hindrance to fishery and impairment of quality for use of sea water. Marine pollution is associated with the changes in physical, chemical and biological conditions of the sea water. This water is also unfit for human consumption and industrial purposes because of high salt content. Chemically it is a solution of 0.5 m NaCl and 0.005 m MgSO4 containing traces of all conceivable matter in the universe.Today human activities are constantly adding industrial, domestic and agricultural wastes to ground water reservoirs at an alarming rate. Ground water contamination is generally irreversible i.e. once it is contaminated; it is difficult to restore the original water quality of the aquifer. Excessive mineralisation of ground water degrades water quality producing an objectionable taste, odour and excessive hardness. Although the soil mantle through which water passes acts as an adsorbent retaining a large part of colloidal and soluble ions with its cation exchange capacity, but ground water is not completely free from the menace