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Description
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Water is essential and inevitable for the survival of almost all known forms of life on earth. Human civilization, agriculture and industries have historically flourished around rivers and major waterways. Water is important for the existence and growth of industries. Clean and fresh drinking water is essential to human and other lives. In fact, only 1 % of the world s water is usable to us. About 97 % is salty seawater and 2 % is frozen in glaciers and polar ice caps. Thus 1 % of the world s water supply is a precious commodity necessary for our survival. Contaminated water may contain harmful elements, which could cause illness and death if ingested. Hence, the quality of water is of vital concern for the mankind since it is directly linked with human welfare. But, much of the available freshwater is being contaminated with harmful elements such as sulfuric acid, fertilizer and gasoline. This happens as fresh water circulates through the hydrologic cycle. As precipitation passes through the atmosphere and flows over roads, agricultural fields and other human-made objects, it picks up contaminants that often make it unusable. These contaminants are then carried to the streams.
