Sources of Water Pollution:
Approximately 33 percent of water pollution is by domestic sources, followed by agriculture- livestock with 29 percent, 27 percent by industry, and 11 percent from other sources.
1. Domestic: domestic sewage is wastewater generated from household activities. It is 99.9 percent pure water, remaining 0.1 percent are pollutants that are both organic and inorganic materials. Organic materials are food and vegetable waste, excreta, and fecal matter whereas inorganic materials such as phosphates and nitrates come from soaps and detergents.
In theory, sewage is an entirely natural matter that should degrade blandly in the environment. In reality, the sewage may contain a host of chemical substances, from drugs, papers, and plastics. to the toilet flushes. nearly everyone dispenses various chemicals of one type or another into their drainage system. Soaps and detergents used in washing machines and dishwashers are finally drained into the sewage.
2. Agriculture: It is undoubted that extensive use of fertilizers and pesticides, collectively known as ago-chemicals, increases agricultural output. These mostly artificial chemicals move into the water bodies along with rainfall and groundwater by leaching. Such as chemicals are persistent and may often gain entry into the food chain causing numerous problems in the animals.
3. Industries:Most of the industries are situated along the banks of the river for convenience and disposal of effluents. Often these effluents comprise acids, bases, dyes, paints, and a range of other chemicals. Detergents form white foam. The industrial waste can be mercury lead, cadmium, chlorides, fluorides, ammonia, etc. Such an addition alerts the pH of the water and turns it into a condition that is fatal to aquatic forms.
The industries regularly discharge heavy amounts of superhead water used in thermal power plants, oil refineries, nuclear power plants, etc. Such high-temperature injuries kill the aquatic flora and fauna. High temperature also reduces the amount of oxygen dissolved in water may harm or even kill aquatic life, the condition is known as Thermal Pollution.
4. Rain Drainage: Rain drainage carries substances like highway debris, oil, chemicals from vehicular exhausts, sediments from the public road and house construction, acids, and radioactive wastes into the freshwater systems as well as into the marine systems. Animal waste from farms and feedlots is also transported along with rainwater. These pollutants impair rivers and streams, groundwater, and even the shoreline waters. Antibiotics, hormones, and other chemicals used to rear farm animals are components of such animal wastes. Pesticides and fertilizer residues from croplands also add to aquatic pollution via rain drainage.