Specific Sources of Water Pollution

Specific Sources of Water Pollution

Farming:

* Farms often use large amounts of herbicides and pesticides, both of which are toxic pollutants. These substances are particularly dangerous to life in rivers, streams and lakes, where toxic substances can build up over a period of time.

* Farms also frequently use large amounts of chemical fertilizers that are washed into the waterways and damage the water supply and the life within it. Fertilizers can increase the amounts of nitrates and phosphates in the water, which can lead to the process of eutrophication.

* Allowing livestock to graze near water sources often results in organic waste products being washed into the waterways. This sudden introduction of organic material increaces the amount of nitrogen in the water, and can also lead to eutrophication.

* Four hundred million tons of soil are carried by the Mississippi River to the Gulf of Mexico each year. A great deal of this siltation is due to runoff from the exposed soil of agricultural fields. Excessive amounts of sediment in waterways can block sunlight, preventing aquatic plants from photosynthesizing, and can suffocate fish by clogging their gills.

Business:

* Clearing of land can lead to erosion of soil into the river.

* Waste and sewage generated by industry can get into the water supply, introducing large organic pollutants into the ecosystem.

* Many industrial and power plants use rivers, streams and lakes to despose of waste heat. The resulting hot water can cause thermal pollution. Thermal pollution can have a disasterous effect on life in an aquatic ecosystem as temperature increaces decreace the amount of oxygen in the water, thereby reducing the number of animals that can survive there.

* Water can become contaminated with toxic or radioactive materials from industry, mine sites and abandoned hazardous waste sites.

* Acid precipitation is caused when the burning of fossil fuels emits sulfur dioxide into the atmosphere. The sulfur dioxide reacts with the water in the atmosphere, creating rainfall which contains sulfuric acid. As acid precipitation falls into lakes, streams and ponds it can lower the overall pH of the waterway, killing vital plant life, thereby affecting the whole food chain. It can also leach heavy metals from the soil into the water, killing fish and other aquatic organisms. Because of this, air pollution is potentially one of the most threatening forms of pollution to aquatic ecosystems.

Homes:

* Sewage generated by houses or runoff from septic tanks into nearby waterways, introduce organic pollutants that can cause eutrophication.