Water pollution
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225182965
2008-07-12T09:34:55Z
R.steenhard
7464138
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[[Image:Nrborderborderentrythreecolorsmay05-1-.JPG|thumb|right|300px|[[Raw sewage]] and [[industrial waste]] flows into the U.S. from Mexico as the [[New River (California)|New River]] passes from [[Mexicali]], Baja California to [[Calexico, California]]]]
'''Water pollution''' is the contamination of [[water]] bodies such as [[lake]]s, [[river]]s, [[ocean]]s, and [[groundwater]] caused by human activities, which can be harmful to organisms and plants which live in these water bodies.
Although natural phenomena such as [[volcano]]es, [[algae bloom]]s, [[storm]]s, and [[earthquake]]s also cause major changes in [[water quality]] and the ecological status of water, water is typically referred to as polluted when it impaired by anthropogenic contaminants and either does not support a human use (like serving as drinking water) or undergoes a marked shift in its ability to support its constituent biotic communities. Water pollution has many causes and characteristics. The primary sources of water pollution are generally grouped into two categories based on their point of origin. Point-source pollution refers to contaminants that enter a waterway through a discrete "point source". Examples of this category include discharges from a wastewater treatment plant, outfalls from a factory, leaking underground tanks, etc. The second primary category, non-point source pollution, refers to contamination that, as its name suggests, does not originate from a single discrete source. Non-point source pollution is often a cumulative effect of small amounts of contaminants gathered from a large area. Nutrient runoff in stormwater from sheet flow over an agricultural field, or metals and hydrocarbons from an area with high impervious surfaces and vehicular traffic are examples of non-point source pollution. The primary focus of legislation and efforts to curb water pollution for the past several decades was first aimed at point sources. As point sources have been effectively regulated, greater attention has come to be placed on non-point source contributions, especially in rapidly urbanizing/suburbanizing or developing areas.
The specific contaminants leading to pollution in water include a wide spectrum of [[chemical]]s, [[pathogen]]s, and physical or sensory changes. While many of the chemicals and substances that are regulated may be naturally occurring (iron, manganese, etc) the concentration is often the key in determining what is a natural component of water, and what is a contaminant. Many of the chemical substances are [[toxic]]. Pathogens can produce [[waterborne diseases]] in either human or animal hosts. Alteration of water's physical chemistry include acidity, [[electrical conductivity]], temperature, and eutrophication. [[Eutrophication]] is the [[fertilisation]] of [[surface water]] by [[nutrients]] that were previously [[scarce]]. Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases,<ref name="death">{{cite news |url=http://finance.yahoo.com/columnist/article/trenddesk/3748 |author=Pink, Daniel H. |publisher=Yahoo |title=Investing in Tomorrow's Liquid Gold |date=April 19, 2006}}</ref><ref name="death2">{{cite news |url=http://environment.about.com/od/environmentalevents/a/waterdayqa.htm |author=West, Larry |publisher=About |title=World Water Day: A Billion People Worldwide Lack Safe Drinking Water |date=March 26, 2006}}</ref> and that it accounts for the deaths of more than 14,000 people daily.<ref name="death2" />
{{Pollution}}
==Contaminants==
Contaminants may include [[organic compound|organic]] and [[inorganic]] substances.
Some organic water pollutants are:
* [[Insecticide]]s and [[herbicide]]s, a huge range of [[organohalide]] and other chemicals
* [[Bacteria]], often is from sewage or [[livestock]] operations
* [[Food processing]] waste, including pathogens
* [[Tree]] and brush debris from [[logging]] operations
* [[Volatile organic compounds|VOCs]] (volatile organic compounds), such as industrial [[solvent]]s, from improper storage
* [[DNAPL]]s (dense non-aqueous phase liquids), such as [[chlorinated solvent]]s, which may fall at the bottom of reservoirs, since they don't mix well with water and are more dense
* Petroleum Hydrocarbons including fuels (gasoline, diesel, jet fuels, and fuel oils) and lubricants (motor oil) from oil field operations, refineries, pipelines, retail service station's underground storage tanks, and transfer operations. Note: VOCs include gasoline-range hydrocarbons.
* [[Detergents]]
* Various [[chemical compounds]] found in personal [[hygiene]] and [[cosmetic]] products
* [[Disinfection by-product]]s (DBPs) found in chemically [[disinfection|disinfected]] [[drinking water]]
Some inorganic water pollutants include:
* [[Heavy metals]] including acid mine drainage
* [[Acidity]] caused by industrial discharges (especially [[sulfur dioxide]] from [[power plants]])
* Pre-production industrial raw resin pellets, an industrial pollutant
* [[Chemical waste]] as industrial by products
* [[Fertilizer]]s, in runoff from [[agriculture]] including [[nitrates]] and [[phosphate]]s
* [[Silt]] in [[surface runoff]] from [[construction]] sites, [[logging]], [[slash and burn]] practices or land clearing sites
Macroscopic, that is, large visible items polluting the water are termed [[marine debris]], and can include such items as:
*[[Nurdle]]s, small ubiquitous waterborne plastic pellets
*[[Shipwreck]]s, large derelict ships
== Transport and chemical reactions of water pollutants ==
Most water pollutants are eventually carried by the rivers into the oceans. In some areas of the world the influence can be traced hundred miles from the mouth by studies using [[hydrology transport model]]s. Advanced [[computer model]]s such as [[SWMM]] or the [[DSSAM Model]] have been used in many locations worldwide to examine the fate of pollutants in aquatic systems. Indicator [[filter feeding]] species such as [[copepods]] have also been used to study pollutant fates in the [[New York Bight]], for example. The highest [[toxin]] loads are not directly at the mouth of the [[Hudson River]], but 100 kilometers south, since several days are required for incorporation into [[plankton]]ic tissue. The Hudson discharge flows south along the coast due to [[coriolis force]]. Further south then are areas of [[hypoxia (environmental)|oxygen depletion]], caused by chemicals using up oxygen and by [[algae bloom]]s, caused by excess [[nutrient]]s from algal cell death and decomposition. Fish and [[shellfish]] kills have been reported, because toxins climb the foodchain after small fish consume [[copepods]], then large fish eat smaller fish, etc. Each successive step up the food chain causes a stepwise concentration of pollutants such as [[heavy metals]] (e.g. [[mercury (element)|mercury]]) and [[persistent organic pollutants]] such as [[DDT]]. This is known as biomagnification which is occasionally used interchangeably with bioaccumulation.
The big gyres in the oceans trap floating [[plastic debris]]. The [[North Pacific Gyre]] for example has collected the so-called "[[Great Pacific Garbage Patch]]" that is now estimated at two times the size of Texas. Many of these long-lasting pieces wind up in the stomachs of marine birds and animals. This results in obstruction of digestive pathways which leads to reduced appetite or even starvation.
Many chemicals undergo reactive [[decay]] or chemically change especially over long periods of time in [[groundwater]] reservoirs. A noteworthy class of such chemicals are the [[chlorinated hydrocarbons]] such as [[trichloroethylene]] (used in industrial metal degreasing and electronics manufacturing) and [[tetrachloroethylene]] used in the dry cleaning industry (note latest advances in liquid carbon dioxide in dry cleaning that avoids all use of chemicals). Both of these chemicals, which are [[carcinogens]] themselves, undergo partial decomposition reactions, leading to new hazardous chemicals (including dichloroethylene and vinyl chloride).
[[Groundwater]] pollution is much more difficult to abate than surface pollution because groundwater can move great distances through unseen [[aquifer]]s. Non-porous aquifers such as [[clay]]s partially purify water of bacteria by simple filtration (adsorption and absorption), dilution, and, in some cases, chemical reactions and biological activity: however, in some cases, the pollutants merely transform to [[soil contaminant]]s. Groundwater that moves through cracks and [[caverns]] is not filtered and can be transported as easily as surface water. In fact, this can be aggravated by the human tendency to use natural [[sinkhole]]s as dumps in areas of [[Karst]] topography.
There are a variety of secondary effects stemming not from the original pollutant, but a derivative condition. Some of these secondary impacts are:
* [[Silt]] bearing [[surface runoff]] from can inhibit the penetration of sunlight through the water column, hampering [[photosynthesis]] in aquatic plants.
* [[Thermal pollution]] can induce fish kills and invasion by new [[thermophilic]] species. This can cause further problems to existing wildlife.
==Sampling & monitoring==
[[Image:Research- water sampling equipment.jpg|thumb|[[environmental science|Environmental Scientists]] preparing water autosamplers.]]
Sampling water can take several forms depending on the accuracy needed and the characteristics of the contaminant. Many contamination events are temporal and most commonly in association with rain events. For this reason 'grab' samples can be used as indicators, but are often inadequate for fully accessing contaminant concerns in a water body. Scientists gathering this type of data often employ auto-sampler devices that pump increments of water at either time or [[Discharge (hydrology)|discharge]] intervals.
==Regulatory framework==
In the [[United Kingdom|UK]] there are [[common law]] rights (civil rights) to protect the passage of water across land unfettered in either quality of quantity. Criminal laws dating back to the 16th century exercised some control over water pollution but it was not until the ''River (Prevention of pollution )Acts 1951 - 1961'' were enacted that any systematic control over water pollution was established. These laws were strengthened and extended in the ''Control of Pollution Act 1984'' which has since been updated and modified by a series of further acts. It is a criminal offense to either pollute a lake, river, groundwater or the sea or to discharge any liquid into such water bodies without proper authority. In England and Wales such permission can only be issued by the [[Environment Agency]] and in Scotland by [[Scottish Environment Protection Agency|SEPA]].
In the [[USA]], concern over water pollution resulted in the enactment of state anti-pollution laws in the latter half of the 19th century, and federal legislation enacted in 1899. The [[Refuse Act]] of the federal [[Rivers and Harbors Act of 1899]] prohibits the disposal of any refuse matter from into either the nation's navigable rivers, lakes, streams, and other navigable bodies of water, or any tributary to such waters, unless one has first obtained a permit. The [[Water Pollution Control Act]], passed in 1948, gave authority to the Surgeon General to reduce water pollution.
Growing public awareness and concern for controlling water pollution led to enactment of the Federal Water Pollution Control Act Amendments of 1972. As amended in 1977, this law became commonly known as the [[Clean Water Act]]. The Act established the basic mechanisms for regulating contaminant discharge. It established the authority for the [[United States Environmental Protection Agency]] to implement wastewater standards for industry. The Clean Water Act also continued requirements to set water quality standards for all contaminants in surface waters. Further amplification of the Act continued including the enactment of the Great Lakes Legacy Act of 2002.<ref>Public Law 107-303, November 27, 2002</ref>
{{mergeto|Safe Drinking Water Act|date=June 2008}}
In 2004, the [[United States Environmental Protection Agency]] tested drinking water quality on commercial airline's aircraft and found that 15 percent of tested aircraft tested positive for total coliform bacteria, according to a press release issued on Friday March 28, 2008. {{Fact|date=April 2008}}
==References==
{{reflist}}
==See also==
*[[Aquatic toxicology]]
*[[Cultural eutrophication]]
*[[Oil spills]]
*[[Marine debris]]
*[[Trophic state index]]
==External links==
{{commons|Water pollution|Water pollution}}
* [http://www.freewebs.com/baconmancomics/news.htm Detailed information about water pollution in built up areas.]
* [http://reportpollution.com Report Pollution from Ships]
*[http://www.black-tides.com www.black-tides.com - An educational website for young people on oil spills]
*[http://www.whoi.edu/institutes/coi/topicIndex.do?o=read&id=9 Coastal Pollution Information from the Coastal Ocean Institute], [[Woods Hole Oceanographic Institution]]
*[http://www.epa.gov/lawsregs/laws/cwa.html U.S. Environmental Protection Agency Clean Water Act]
*[http://cfpub.epa.gov/caddis/ EPA Causal Analysis/Diagnosis Decision Information System (CADDIS) - Stressor Identification]
*[http://digital.library.unt.edu/govdocs/crs/search.tkl?type=subject&q=water%20pollution&q2=liv Congressional Research Service (CRS) Reports regarding Water Pollution]
*[http://www.nrdc.org/water/pollution/default.asp Natural Resources Defense Council (NRDC): overviews, news and reports on water pollution]
*[http://www.pbs.org/strangedays/episodes/troubledwaters/ Troubled Waters: Episode and web site from National Geographic/PBS's "Strange Days on Planet Earth"]
*[http://www.epa.sa.gov.au/water_quality.html Water Quality in South Australia]
*[http://www.thetripflare.org/ Original case-study of the sustained criminal pollution of Long Lake, a tributary of the Mississippi, by Chemetco]
*[http://www.beyondpesticides.org/documents/water.pdf Threatened Waters: Turning the Tide on Pesticide Contamination, by Beyond Pesticides]
*[http://www.awra.org American Water Resources Association]
*[http://r.engel.free.fr/?p=209 Water shortage in the future and its consequences (Slide Show)]
*[http://www.ppl.nl/index.php?option=com_wrapper&view=wrapper&Itemid=82 Bibliography on Water Resources and International Law] Peace Palace Library
[[Category:Environmental science]]
[[Category:Water pollution| ]]
[[Category:Water chemistry]]
[[Category:Aquifers]]
[[Category:Aquatic ecology]]
[[Category:Water supply]]
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