As a result it plays important roles in ecosystem support, economic development, cultural values and community well-being. Dozens of times a day those of us who live in the industrialized nations of the world enjoy a blessing denied to 75 percent of the world population: abundant supplies of clean water. But water is essential for life on earth. No known organisms can live without it. For centuries water has been used as a dumping ground for human sewage and industrial wastes. Added to them are the materials leached out and transported from land by water percolating through the soil and running off its surface to aquatic ecosystems.
Water pollution is degradation of water quality. Any physical, chemical, or biological change in water quality that adversely affects living organisms or makes water unsuitable for desired use can be considered pollution. Thus the term water pollution refers to – “Water contamination by a variety of chemical substances or transportation caused by several nutrients and fertilizers. ” – Southwest, 1 976 U. S. Department of Health Education and Welfare defines water pollution as – “The adding to water of any substance or the changing of water’s physical and chemical characteristics in any way which interferes with its use of legitimate purposes”.
At present, water pollution is a major global problem. Everyday many people are dying for water pollution. Now water pollution becomes the leading cause of death & diseases. 3 1. 2 Sources of Water Pollution : There are many sources of water pollution. But before knowing that, we need to know that what are the sources of water, and then we will understand how they are becoming polluted. We get water from two sources – Surface Water Ground Water Surface Water is fresh water found on Earth’s surface in streams and rivers, lakes, ponds, reservoirs.
Surface waters are replenished by the runoff of precipitation from the land and are therefore considered a renewable, although finite resource. Ground Water refers to the fresh water under Earth’s surface that is stored in aquifers. This water originates as rain or melting snow that seeps into the soil and finds its way down through cracks and spaces in sand, gravel or rock until it is stopped by an impenetrable layer, there it accumulates as groundwater. Surface water and groundwater have often been studied and managed as separate resources, although they are interrelated. Surface water seeps wrought the soil and becomes groundwater.
Conversely, groundwater can also feed surface water sources. Sources of surface water pollution are generally grouped into two categories based on their origin. Point Sources Non-point Sources Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain. Point source water pollution are easily findable. So, people can easily control them. Non-point source illusion refers to diffuse contamination that does not originate from a single discrete source.
Non-point source pollution is often the cumulative effect of small amounts of contaminants gathered from a large area. A common example is the leaching out of nitrogen compounds from fertilized agricultural lands. Nutrient runoffs in storm water from “sheet flow” over an agricultural field or a forest are also cited as examples of Non-point source pollution. 4 Surface Water Pollution : Surface water bodies are extensively used for disposal of untreated industrial wastes and this is one of the main sources of surface water pollution.
Surface water pollution is caused by – C Domestic Waste : Water pollution Of domestic is mainly caused by sewage. Sewage is defined as the waterborne waste derived from home, animal or food processing plants and includes human excreta, soaps, organic materials, different types of solids, waste food, oil detergents, paper and cloth. They are the largest group of water pollutants. Water pollution is caused by uncontrolled dumping of waste collected from villages, towns and cities into ponds, streams, lakes and rivers. C] Industrial Effluent : The discharge of industrial effluents into the water body caused water pollution.