Different Kinds of Water Pollutants

Contaminated water often lies on top of the ground before sinking into the watershed.

Water pollution has a direct impact on ecosystems and human health. Access to clean water is vital for drinking, cleaning and irrigation of crops. Pollutants range from natural-occurring sediments to human-created toxic waste. Different pollutants create different problems, but they are all difficult to control. Once pollutants enter a river or lake, they quickly spread throughout the whole watershed.

Farm Chemicals

Chemicals used in farming are a major source of water pollution. Fertilizers and pesticides are applied on the top of the ground to promote and maximize crop growth. These chemicals may enter the water by seeping through the ground and contaminating the water table, or they can get washed into watersheds by rain runoff. Fertilizers may be chemicals sprayed on the crops, but manure is also used. Both contain nitrates and phosphates, which will promote aquatic plant growth, including algae. Algal blooms can be devastating to a lake or pond. The algae consume oxygen and prevent sunlight from penetrating the water. Fish kills are a common result of excessive algae promotion.

Sediments

Sediments, such as sand and silt, are a common pollutant that is not chemical in origin. Sediments may enter the water stream in many ways. Erosion of nearby riverbanks or lake shores are a natural source of sediment. The rate of erosion may be increased by humans or animals by digging or disturbing the land. Sediments may also enter the watershed by severe weather. Heavy rains erode the shores, and floods bring sediments from other locations. Droughts may also contribute. Dry, arid land is very susceptible to wind erosion. Other sediments are a result of construction, deforestation and dirt from roads. Rain washes materials off the road and into the watershed. Sediment will slowly fill the bottom of the body of water. This disturbs the organisms in the water by making it uninhabitable. Organic materials that enter the water, such as leaves, tree bark and grass, will begin to decompose. This process consumes the oxygen, killing the fish.

Sewage

Sewage pollution is a direct result of human activities. Wastewater is often dumped directly into lakes, rivers or the ocean. This waste is not always treated first. Raw sewage creates a health hazard for all organisms in the vicinity. Bacterial outbreaks occur, such as e coli, which can cause serious illness.

Environmental Contaminants

Water pollution that results from industrial contamination is usually highly publicized. This type of pollution often occurs from accidents or improper handling of toxic waste. Oil and radioactive waste are two extremely dangerous pollutants that can devastate a watershed. Oil spills can result in millions of barrels of oil entering the ocean. This oil coats the top of the water and injures all types of sea creatures. Radioactive waste enters the water from factories that improperly handle the waste product. Radioactive materials get into the drinking water and cause serious health problems.

References

• Water Pollution and Society