Water pollution occurs when pollutants are released into the water before they are treated to remove any of their harmful compounds. Polluted water causes the destruction of plants and organisms living in or around the polluted body of water. Contaminated water also harms people, plants and creatures who consume it. Water pollution can be caused by pathogens, inorganic compounds, organic material and macroscopic pollutants.
Bacteria are commonly found in water; it is when they start to increase in numbers that are above safe levels that water contamination occurs. Two of the most common pathogen pollutants are Coliform and E. coli bacteria. Coliforms are normally present in the environment in safe levels and can actually be used to detect other pathogens in water. However, Water Filter Review reports that if coliforms increase in numbers, it can be dangerous for the health of the environment. The presence of E. coli bacteria indicates that water has been contaminated with human or animal wastes.
Inorganic materials such as heavy metals--arsenic, mercury, copper, chromium, zinc and barium, for example--though harmless in small concentrations, act as pollutants when they end up in the water due to heavy industrialization or industrial accidents. This kind of water pollution can cause severe health problems and can even be fatal.
These materials contain molecules which have carbon in their make-up. One of the most frequently detected volatile organic chemicals is Methyl Tertiary Butyl Ether (MTBE). MTBE was used as an air-cleaning gas additive, and was once added to gasoline. Although it is now a banned chemical, it will take years before MBTE is thoroughly removed from contaminated water systems. Water contaminated with this organic chemical can cause leukemia, lymphoma and tumors in testicles, the thyroid glands and kidneys.
Macroscopic pollution is when large, visible items pollute the water. The first common pollutant is trash--paper, plastic or food waste. It is either thrown directly into the water or washed away by the rain into a body of water. Other types of macroscopic pollution include nurdles (small waterborne plastic pellets); pieces of wood; metals; and even obvious things like shipwrecks. This form of pollution is the most manageable; however, these pollutants must be removed in order to avoid loss of life in aquatic animals and contamination upon the chemical breakdown of these objects.