Water Pollution

Pollution of water is a broad subject dealing with different types of pollutants entering the hydrological cycle. Surface flowing river water, underground water and vast sea water are included in a broad subject of water pollution. Out of them, drinking water pollution is most important, as such a pollution is directly connected with human health. Water being indispensable part of human body, the daily intake of water is of utmost important for all physiological activities. If such daily used drinking water is polluted - the health of human beings will be badly affected. A general information about water pollution is presented below-with an emphasis on drinking water pollution.

Types of Water Pollution

Based on the utility and locations of water the types of water pollution are grouped as

• Drinking water pollution

• Ground water pollution

• River water pollution

• Sea water pollution

Based on source of pollution, the following types of water pollution are recognised

• Water pollution due to city wastes

• Water pollution due to agriculture

• Industrial water pollution

• Water pollution due to natural reasons

Based on severity of pollution, the water pollution could be classified as

• Dangerous / serious water pollution

• Mild and rectifiable water pollution

• Negligible water pollution

Quite frequently, a water pollution could find a place in two or more groups. For e.g., an agricultural water pollution may be serious and industrial water pollution may be mild or sea water may be polluted by agricultural chemical and underground water may be polluted by city wastes.

Although all the above groupings are meaningful, it is more convenient if the classification based on utility and location of water is considered for detailed discussion. In this classification, drinking water pollution can be caused by its source and during its path of movement. Thus, the ground water pollution and river water pollution may ultimately lead to drinking water pollution when ground water or river is polluted. River water and underground water can lead to many other complications other than drinking water pollution alone. It is to be observed that sea water is significantly polluted, although no pollutant is directly added to sea (except accidental ship leakage or sinking of ship etc). This is because, all polluted rivers lead to pollutants to sea and due to continuous accumulation, the concentration of pollutants in sea water gets increased as the time passes.

Important Features of Water Pollution

• Water pollution can be point source or non - point source. That is, it can be caused near the source of pollution or where source of pollution is sometimes far away from source.

• Nature also contributes to water pollution besides human activities.

• The concentration of pollutants is generally on reducing trend, as the water moves to longer distances / depths and as the time passes.

• Not all pollutants in water are dangerous. And not all dangerous pollutants are really harmful. Few pollutants are not dangerous immediately. But they may cause ill effects after long time.

• The sensitivity to pollutants in drinking water is more connected to physiology of human / animal body than concentration of pollutant within safe range.