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POINT AND NON POINT SOURCES OF WATER POLLUTION
Jun 11, 2014

Water pollution is change in its Physical, chemical or biological characteristics which adversely affects the any living thing which uses it.

SOURCES OF WATER POLLUTION :

  • There are various classifications of water pollution. 

  • The two chief sources of water pollution can be seen as Point and Non Point.

  • Pollution originating from a single, identifiable source, such as a discharge pipe from a factory or sewage plant, is called point-source pollution. Here source of pollution is single. 

  • But pollution that does not originate from a single source, or point, is called nonpoint-source pollution. 

  • Liquid, solid, and airborne discharges from point sources as well as pollutants from nonpoint sources may go either into surface water or into the ground. (Airborne pollutants can be assimilated into rainwater and can affect water quality: acid rain is an example.) The ability for these pollutants to reach surface water or groundwater is enhanced by the amount of water available from precipitation (rain) or irrigation.


POINT SOURCES :

Point-source pollutants in surface water and groundwater are usually found in a plume that has the highest concentrations of the pollutant nearest the source (such as the end of a pipe or an underground injection system) and diminishing concentrations farther away from the source. The various types of point-source pollutants found in waters are as varied as the types of business, industry, agricultural, and urban sources that produce them.

  • Commercial and industrial businesses use hazardous materials in manufacturing or maintenance, and then discharge various wastes from their operations. The raw materials and wastes may include pollutants such as solvents, petroleum products (such as oil and gasoline), or heavy metals. 

  • Point sources of pollution from agriculture may include animal feeding operations, animal waste treatment lagoons, or storage, handling, mixing, and cleaning areas for pesticides, fertilizers, and petroleum. 

  • Municipal point sources might include wastewater treatment plants, landfills, utility stations, motor pools, and fleet maintenance facilities.

For all of these activities, hazardous materials may be included in the raw materials used in the process as well as in the waste stream for the facility. If the facility or operator does not handle, store, and dispose of the raw materials and wastes properly, these pollutants could end up in the water supply. This may occur through discharges at the end of a pipe to surface water, discharges on the ground that move through the ground with infiltrating rainwater, or direct discharges beneath the ground surface.

NON POINT SOURCES :

Non point-source pollution occurs as water moves across the land or through the ground and picks up natural and human-made pollutants, which can then be deposited in lakes, rivers, wetlands, coastal waters, and even groundwater. The water that carries nonpoint-source pollution may originate from natural processes such as rainfall or snowmelt, or from human activities such as crop irrigation or lawn maintenance.

Non point-source pollution is usually found spread out throughout a large area. It is difficult to trace the exact origin of these pollutants because they result from a wide variety of human activities on the land as well as natural characteristics of the soil, climate, and topography.


The most common nonpoint-source pollutants are:

  • Sediment, nutrients, microorganisms and toxics. Sediment can degrade water quality by contaminating drinking water supplies or silting in spawning grounds for fish 

  • Nonpoint sources of pollution in urban areas may include parking lots, streets, and roads where storm water picks up oils, grease, metals, dirt, salts, and other toxic materials.

  • In areas where crops are grown or in areas with landscaping (including grassy areas of residential lawns and city parks), irrigation, and rainfall can carry soil, pesticides, fertilizers, herbicides, and insecticides to surface water and groundwater.

  • Bacteria, microorganisms, and nutrients (nitrogen and phosphorus) are common nonpoint-source pollutants from agricultural livestock areas and residential pet wastes. These pollutants are also found in areas where there is a high density of septic systems or where the septic systems are faulty or not maintained properly. 

  • Other pollutants from nonpoint sources include salt from irrigation practices or road de-icing, and acid drainage from abandoned mines.

 

 


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