Water pollution

From WikiProjectMed
Jump to navigation Jump to search

Raw sewage and industrial waste in the New River as it passes from Mexicali (Mexico) to Calexico, California

Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses.[1]: 6  Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. Water pollution can be attributed to one of four sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater.[2] It can be grouped into surface water pollution (either fresh water pollution or marine pollution) or groundwater pollution. For example, releasing inadequately treated wastewater into natural waters can lead to degradation of these aquatic ecosystems. Water pollution can also lead to water-borne diseases for people using polluted water for drinking, bathing, washing or irrigation.[3] Water pollution reduces the ability of the body of water to provide the ecosystem services (such as drinking water) that it would otherwise provide.

Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain, a wastewater treatment plant or an oil spill. Non-point sources are more diffuse, such as agricultural runoff.[4] Pollution is the result of the cumulative effect over time. Pollution may take the form of toxic substances (e.g., oil, metals, plastics, pesticides, persistent organic pollutants, industrial waste products), stressful conditions (e.g., changes of pH, hypoxia or anoxia, increased temperatures, excessive turbidity, unpleasant taste or odor, and changes of salinity), or pathogenic organisms. Contaminants may include organic and inorganic substances. Heat can also be a pollutant, and this is called thermal pollution. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.

Control of water pollution requires appropriate infrastructure and management plans as well as legislation. Technology solutions can include improving sanitation, sewage treatment, industrial wastewater treatment, agricultural wastewater treatment, erosion control, sediment control and control of urban runoff (including stormwater management). Effective control of urban runoff includes reducing speed and quantity of flow.


A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses".[1]: 6  Therefore, pollution is associated with concepts attributed to humans, namely the negative alterations and the uses of the water body. Water is typically referred to as polluted when it is impaired by anthropogenic contaminants. Due to these contaminants it either does not support a human use, such as drinking water, or undergoes a marked shift in its ability to support its biotic communities, such as fish.


Contaminants with an origin in sewage

The following compounds can all reach water bodies via raw sewage or even treated sewage discharges:

  • Various chemical compounds found in personal hygiene and cosmetic products.

If the water pollution stems from sewage (municipal wastewater), the main pollutants are: suspended solids, biodegradable organic matter, nutrients and pathogenic (disease-causing) organisms.[1]: 6 

Poster to teach people in South Asia about human activities leading to the pollution of water sources
Pollutants and their effects (sources of these pollutants are municipal and industrial wastewater, urban runoff, agricultural and pasture activities). Adapted from [1]: 7 
Pollutant Main representative parameter Possible effect of the pollutant
Suspended solids Total suspended solids
Biodegradable organic matter Biological oxygen demand
  • Oxygen consumption
  • Death of fish
  • Septic conditions
Pathogens Waterborne diseases
Non-biodegradable organic matter
Inorganic dissolved solids


The major groups of pathogenic organisms are: (a) bacteria, (b) viruses, (c) protozoans and (d) helminths.[1]: 47  In practice, indicator organisms are used to investigate pathogenic pollution of water because the detection of pathogenic organisms in water sample is difficult and costly, because of their low concentrations. The indicators (bacterial indicator) of fecal contamination of water samples most commonly used are: total coliforms (TC), fecal coliforms (FC) or thermotolerant coliforms, escherichia coli (EC).[1]: 47 

Pathogens can produce waterborne diseases in either human or animal hosts.[10] Some microorganisms sometimes found in contaminated surface waters that have caused human health problems include: Burkholderia pseudomallei, Cryptosporidium parvum, Giardia lamblia, Salmonella, norovirus and other viruses, parasitic worms including the Schistosoma type.[11]

The source of high levels of pathogens in water bodies can be from human feces (due to open defecation), sewage, blackwater, manure that has found its way into the water body. The cause for this can be lack of sanitation or poorly functioning on-site sanitation systems (septic tanks, pit latrines), sewage treatment plants without disinfection steps, sanitary sewer overflows and combined sewer overflows (CSOs)[12] during storm events and intensive agriculture (poorly managed livestock operations).

Organic compounds

Organic substances that enter water bodies are often toxic.[13]: 229 

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants.[15][16]

Inorganic contaminants

Bauxite residue is an industrial waste that is dangerously alkaline and can lead to water pollution if not managed appropriately (photo from Stade, Germany).
Muddy river polluted by sediment.

Inorganic water pollutants include for example:

Pharmaceutical pollutants

Solid waste and plastics

Solid waste and plastics in the Lachine Canal, Canada.

Solid waste can enter water bodies through untreated sewage, combined sewer overflows, urban runoff, people discarding garbage into the environment, wind carrying municipal solid waste from landfills and so forth. This results in macroscopic pollution– large visible items polluting the water– but also microplastics pollution that is not directly visible. The terms marine debris and marine plastic pollution are used in the context of pollution of oceans.

Microplastics persist in the environment at high levels, particularly in aquatic and marine ecosystems, where they cause water pollution.[23] 35% of all ocean microplastics come from textiles/clothing, primarily due to the erosion of polyester, acrylic, or nylon-based clothing, often during the washing process.[24]

Types of surface water pollution

Surface water pollution includes pollution of rivers, lakes and oceans. A subset of surface water pollution is marine pollution which affects the oceans. Nutrient pollution refers to contamination by excessive inputs of nutrients.

Globally, about 4.5 billion people do not have safely managed sanitation as of 2017, according to an estimate by the Joint Monitoring Programme for Water Supply and Sanitation.[25] Lack of access to sanitation is concerning and often leads to water pollution, e.g. via the practice of open defecation: during rain events or floods, the human feces are moved from the ground where they were deposited into surface waters. Simple pit latrines may also get flooded during rain events.

Thermal pollution

The Brayton Point Power Station in Massachusetts discharges heated water to Mount Hope Bay.

Elevated water temperatures decrease oxygen levels (due to lower levels of dissolved oxygen, as gases are less soluble in warmer liquids), which can kill fish (which may then rot) and alter food chain composition, reduce species biodiversity, and foster invasion by new thermophilic species.[26]: 179 [13]: 375 

Biological pollution

The introduction of aquatic invasive organisms is a form of water pollution as well. It causes biological pollution.[27]

Groundwater pollution

In many areas of the world, groundwater pollution poses a hazard to the wellbeing of people and ecosystems. One-quarter of the world's population depends on groundwater for drinking, yet concentrated recharging is known to carry short-lived contaminants into carbonate aquifers and jeopardize the purity of those waters.[28]

Pollution from point sources

Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain.

The U.S. Clean Water Act (CWA) defines point source for regulatory enforcement purposes (see United States regulation of point source water pollution).[29] The CWA definition of point source was amended in 1987 to include municipal storm sewer systems, as well as industrial storm water, such as from construction sites.[30]


Sewage typically consists of 99.9% water and 0.1% solids.[31] Sewage contributes many classes of nutrients that lead to eutrophication. It is a major source of phosphate for example.[32] Sewage is often contaminated with diverse compounds found in personal hygiene, cosmetics, pharmaceutical drugs (see also drug pollution), and their metabolites[33][34] Water pollution due to environmental persistent pharmaceutical pollutants can have wide-ranging consequences. When sewers overflow during storm events this can lead to water pollution from untreated sewage. Such events are called sanitary sewer overflows or combined sewer overflows.

A polluted river draining an abandoned copper mine on Anglesey

Industrial wastewater

Perfluorooctanesulfonic acid (PFOS) is a global pollutant that has been found in drinking water. It appears not to biodegrade.[35]

Industrial processes that use water also produce wastewater. This is called industrial wastewater. Using the US as an example, the main industrial consumers of water (using over 60% of the total consumption) are power plants, petroleum refineries, iron and steel mills, pulp and paper mills, and food processing industries.[2] Some industries discharge chemical wastes, including solvents and heavy metals (which are toxic) and other harmful pollutants.

<section begin=Pollutants in industrial wastewater/>Industrial wastewater could add the following pollutants to receiving water bodies if the wastewater is not treated and managed properly:

Pollution from nonpoint sources


Agriculture is a major contributor to water pollution from nonpoint sources. The use of fertilizers as well as surface runoff from farm fields, pastures and feedlots leads to nutrient pollution.[41] In addition to plant-focused agriculture, fish-farming is also a source of pollution. Additionally, agricultural runoff often contains high levels of pesticides.[2]

Atmospheric contributions (air pollution)

Acid rain can have harmful effects on plants, aquatic ecosystems, and infrastructure.[42][43]

Acid rain is caused by emissions of sulphur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.[44] Some governments have made efforts since the 1970s to reduce the release of sulfur dioxide and nitrogen oxide into the atmosphere. The main source of sulfur and nitrogen compounds that result in acid rain are anthropogenic, but nitrogen oxides can also be produced naturally by lightning strikes and sulphur dioxide is produced by volcanic eruptions.[45]

Carbon dioxide concentrations in the atmosphere have increased since the 1850s due anthropogenic influences (emissions of greenhouse gases).[46] This leads to ocean acidification and is another form of water pollution from atmospheric contributions.[47]

Sampling, measurements, analysis

Environmental scientists preparing water autosamplers.

Water pollution may be analyzed through several broad categories of methods: physical, chemical and biological. Some methods may be conducted in situ, without sampling, such as temperature. Others involve collection of samples, followed by specialized analytical tests in the laboratory. Standardized, validated analytical test methods, for water and wastewater samples have been published.[48]

Common physical tests of water include temperature, Specific conductance or electrical conductance (EC) or conductivity, solids concentrations (e.g., total suspended solids (TSS)) and turbidity. Water samples may be examined using analytical chemistry methods. Many published test methods are available for both organic and inorganic compounds. Frequently used parameters that are quantified are pH, biochemical oxygen demand (BOD),[49]: 102  chemical oxygen demand (COD),[49]: 104  dissolved oxygen (DO), total hardness, nutrients (nitrogen and phosphorus compounds, e.g. nitrate and orthophosphates), metals (including copper, zinc, cadmium, lead and mercury), oil and grease, total petroleum hydrocarbons (TPH), surfactants and pesticides.

The use of a biomonitor or bioindicator is described as biological monitoring. This refers to the measurement of specific properties of an organism to obtain information on the surrounding physical and chemical environment.[50] Biological testing involves the use of plant, animal or microbial indicators to monitor the health of an aquatic ecosystem. They are any biological species or group of species whose function, population, or status can reveal what degree of ecosystem or environmental integrity is present.[51] One example of a group of bio-indicators are the copepods and other small water crustaceans that are present in many water bodies. Such organisms can be monitored for changes (biochemical, physiological, or behavioral) that may indicate a problem within their ecosystem.


Oxygen depletion, resulting from nitrogen pollution and eutrophication is a common cause of fish kills.


Water pollution is a major global environmental problem because it can result in the degradation of aquatic ecosystems.[citation needed] The specific contaminants leading to pollution in water include a wide spectrum of chemicals, pathogens, and physical changes such as elevated temperature. While many of the chemicals and substances that are regulated may be naturally occurring (calcium, sodium, iron, manganese, etc.) the concentration usually determines what is a natural component of water and what is a contaminant. High concentrations of naturally occurring substances can have negative impacts on aquatic flora and fauna. Oxygen-depleting substances may be natural materials such as plant matter (e.g. leaves and grass) as well as man-made chemicals. Other natural and anthropogenic substances may cause turbidity (cloudiness) which blocks light and disrupts plant growth, and clogs the gills of some fish species.[citation needed]

Fecal sludge collected from pit latrines is dumped into a river at the Korogocho slum in Nairobi, Kenya.

Public health and waterborne diseases

A study published in 2017 stated that "polluted water spread gastrointestinal diseases and parasitic infections and killed 1.8 million people" (these are also referred to as waterborne diseases).[52]

Eutrophication from nitrogen pollution

Nitrogen pollution (a form of water pollution where excessive amounts of nutrients are added to a water body), can cause eutrophication, especially in lakes. Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases the primary productivity of the ecosystem. Depending on the degree of eutrophication, subsequent negative environmental effects such as anoxia (oxygen depletion) and severe reductions in water quality may occur, affecting fish and other animal populations.[1]: 131 

Ocean acidification

Ocean acidification is another impact of water pollution. Ocean acidification is the ongoing decrease in the pH value of the Earth's oceans, caused by the uptake of carbon dioxide (CO
) from the atmosphere.[46]


Water pollution is a problem in developing countries as well as in developed countries.

By country

For example, water pollution in India and China is wide spread. About 90 percent of the water in the cities of China is polluted.[53]

Control and reduction

View of secondary treatment reactors (activated sludge process) at the Blue Plains Advanced Wastewater Treatment Plant, Washington, D.C., United States. Seen in the distance are the sludge digester building and thermal hydrolysis reactors.

Pollution control philosophy

One aspect of environmental protection are mandatory regulations but they are only part of the solution. Other important tools in pollution control include environmental education, economic instruments, market forces and stricter enforcements.[54] Standards can be "precise" (for a defined quantifiable minimum or maximum value for a pollutant), or "imprecise" which would require the use of Best Available Technology (BAT) or Best Practicable Environmental Option (BPEO).[54] Market-based economic instruments for pollution control can include: charges, subsidies, deposit or refund schemes, the creation of a market in pollution credits, and enforcement incentives.[54]

Moving towards a holistic approach in chemical pollution control combines the following approaches: Integrated control measures, trans-boundary considerations, complementary and supplementary control measures, life-cycle considerations, the impacts of chemical mixtures.[54]

Control of water pollution requires appropriate infrastructure and management plans. The infrastructure may include wastewater treatment plants, for example sewage treatment plants and industrial wastewater treatment plants. Agricultural wastewater treatment for farms, and erosion control at construction sites can also help prevent water pollution. Effective control of urban runoff includes reducing speed and quantity of flow.

Water pollution requires ongoing evaluation and revision of water resource policy at all levels (international down to individual aquifers and wells).

Sanitation and sewage treatment

Plastic waste on the big drainage, and air pollution in the far end of the drainage in Ghana

Municipal wastewater (or sewage) can be treated by centralized sewage treatment plants, decentralized wastewater systems, nature-based solutions[55] or in onsite sewage facilities and septic tanks. For example, waste stabilization ponds are a low cost treatment option for sewage, particularly for regions with warm climates.[1]: 182  UV light (sunlight) can be used to degrade some pollutants in waste stabilization ponds (sewage lagoons).[56] The use of safely managed sanitation services would prevent water pollution caused by lack of access to sanitation.[25]

Well-designed and operated systems (i.e., with secondary treatment stages or more advanced tertiary treatment) can remove 90 percent or more of the pollutant load in sewage.[57] Some plants have additional systems to remove nutrients and pathogens. While such advanced treatment techniques will undoubtedly reduce the discharges of micropollutants, they can also result in large financial costs, as well as environmentally undesirable increases in energy consumption and greenhouse gas emissions.[58]

Sewer overflows during storm events can be addressed by timely maintenance and upgrades of the sewerage system. In the US, cities with large combined systems have not pursued system-wide separation projects due to the high cost,[59] but have implemented partial separation projects and green infrastructure approaches.[60] In some cases municipalities have installed additional CSO storage facilities[61] or expanded sewage treatment capacity.[62]

Management of erosion and sediment control

Silt fence installed on a construction site.

Sediment from construction sites can be managed by installation of erosion controls, such as mulching and hydroseeding, and sediment controls, such as sediment basins and silt fences.[63] Discharge of toxic chemicals such as motor fuels and concrete washout can be prevented by use of spill prevention and control plans, and specially designed containers (e.g. for concrete washout) and structures such as overflow controls and diversion berms.[64]

Erosion caused by deforestation and changes in hydrology (soil loss due to water runoff) also results in loss of sediment and, potentially, water pollution.[65][66]

Share of water bodies with good water quality in 2020 (a water body is classified as "good" quality if at least 80% of monitoring values meet target quality levels, see also SDG 6, Indicator 6.3.2)


Some examples for legislation to control water pollution are listed below:


In the Philippines, Republic Act 9275, otherwise known as the Philippine Clean Water Act of 2004,[67] is the governing law on wastewater management. It states that it is the country's policy to protect, preserve and revive the quality of its fresh, brackish and marine waters, for which wastewater management plays a particular role.[67]

See also


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Von Sperling M (2015). "Wastewater Characteristics, Treatment and Disposal". IWA Publishing. 6. doi:10.2166/9781780402086. ISBN 9781780402086. Archived from the original on 2022-06-21. Retrieved 2022-07-29.
  2. 2.0 2.1 2.2 Eckenfelder Jr WW (2000). Kirk‐Othmer Encyclopedia of Chemical Technology. John Wiley & Sons. doi:10.1002/0471238961.1615121205031105.a01. ISBN 978-0-471-48494-3. Archived from the original on 2021-02-11. Retrieved 2022-07-29.
  3. "Water Pollution". Environmental Health Education Program. Cambridge, MA: HarvarT.H. Chan School of Public Health d. July 23, 2013. Archived from the original on 2021-09-18. Retrieved 2021-09-18.
  4. Moss B (February 2008). "Water pollution by agriculture". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 363 (1491): 659–666. doi:10.1098/rstb.2007.2176. PMC 2610176. PMID 17666391.
  5. Alexandrou L, Meehan BJ, Jones OA (October 2018). "Regulated and emerging disinfection by-products in recycled waters". The Science of the Total Environment. 637–638: 1607–1616. Bibcode:2018ScTEn.637.1607A. doi:10.1016/j.scitotenv.2018.04.391. PMID 29925195. S2CID 49355478.
  6. "Environment Agency (archive) – Persistent, bioaccumulative and toxic PBT substances". Environment Agency (UK). Archived from the original on August 4, 2006. Retrieved 2012-11-14.
  7. Natural Environmental Research Council – River sewage pollution found to be disrupting fish hormones Archived 2015-04-27 at the Wayback Machine. Planetearth.nerc.ac.uk. Retrieved on 2012-12-19.
  8. "Endocrine Disruption Found in Fish Exposed to Municipal Wastewater". Reston, VA: US Geological Survey. Archived from the original on October 15, 2011. Retrieved 2012-11-14.
  9. Guidelines for the Safe Use of Wastewater, Excreta and Greywater, Volume 4 Excreta and Greywater Use in Agriculture (third ed.). Geneva: World Health Organization. 2006. ISBN 9241546859. Archived from the original on 2014-10-17. Retrieved 2022-07-29.
  10. Harrison RM (2013). Pollution: Causes, effects, and control (5th ed.). Cambridge, UK: Royal Society of Chemistry. ISBN 978-1-78262-560-5. OCLC 1007100256. Archived from the original on 2022-01-29. Retrieved 2022-07-29.
  11. Schueler, Thomas R. "Microbes and Urban Watersheds: Concentrations, Sources, & Pathways." Reprinted in The Practice of Watershed Protection. Archived January 8, 2013, at the Wayback Machine 2000. Center for Watershed Protection. Ellicott City, MD.
  12. Report to Congress: Impacts and Control of CSOs and SSOs (Report). EPA. August 2004. EPA 833-R-04-001. Archived from the original on 2020-06-23. Retrieved 2022-07-29.
  13. 13.0 13.1 13.2 Laws EA (2018). Aquatic Pollution: An Introductory Text (4th ed.). Hoboken, NJ: John Wiley & Sons. ISBN 9781119304500.
  14. 14.0 14.1 Burton Jr GA, Pitt R (2001). Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers. New York: CRC/Lewis Publishers. ISBN 0-87371-924-7. Archived from the original on 2009-05-19. Retrieved 2022-07-29. Chapter 2.
  15. 15.0 15.1 Johnson MS, Buck RC, Cousins IT, Weis CP, Fenton SE (March 2021). "Estimating Environmental Hazard and Risks from Exposure to Per- and Polyfluoroalkyl Substances (PFASs): Outcome of a SETAC Focused Topic Meeting". Environmental Toxicology and Chemistry. 40 (3): 543–549. doi:10.1002/etc.4784. PMC 8387100. PMID 32452041.
  16. 16.0 16.1 Sinclair GM, Long SM, Jones OA (November 2020). "What are the effects of PFAS exposure at environmentally relevant concentrations?". Chemosphere. 258: 127340. Bibcode:2020Chmsp.258l7340S. doi:10.1016/j.chemosphere.2020.127340. PMID 32563917. S2CID 219974801.
  17. Schueler, Thomas R. "Cars Are Leading Source of Metal Loads in California." Reprinted in The Practice of Watershed Protection. Archived March 12, 2012, at the Wayback Machine 2000. Center for Watershed Protection. Ellicott City, MD.
  18. Kaushal SS, Likens GE, Pace ML, Utz RM, Haq S, Gorman J, Grese M (January 2018). "Freshwater salinization syndrome on a continental scale". Proceedings of the National Academy of Sciences of the United States of America. 115 (4): E574–E583. Bibcode:2018PNAS..115E.574K. doi:10.1073/pnas.1711234115. PMC 5789913. PMID 29311318.
  19. Evans DM, Villamagna AM, Green MB, Campbell JL (August 2018). "Origins of stream salinization in an upland New England watershed". Environmental Monitoring and Assessment. 190 (9): 523. doi:10.1007/s10661-018-6802-4. PMID 30116969. S2CID 52022441.
  20. Cañedo-Argüelles M, Kefford B, Schäfer R (December 2018). "Salt in freshwaters: causes, effects and prospects - introduction to the theme issue". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 374 (1764). doi:10.1098/rstb.2018.0002. PMC 6283966. PMID 30509904.
  21. Knight K (2021). "Freshwater methamphetamine pollution turns brown trout into addicts". Journal of Experimental Biology. 224 (13): jeb242971. doi:10.1242/jeb.242971. ISSN 0022-0949. Archived from the original on 2021-12-12. Retrieved 2022-07-29.
  22. De Lorenzo D (2021-06-18). "MDMA Gangs Are Literally Polluting Europe". Vice World News. Brooklyn, NY: Vice Media Group. Archived from the original on 2022-07-30. Retrieved 2022-07-29.
  23. "Development solutions: Building a better ocean". European Investment Bank. Archived from the original on 2021-10-21. Retrieved 2020-08-19.
  24. Resnick B (2018-09-19). "More than ever, our clothes are made of plastic. Just washing them can pollute the oceans". Vox. Archived from the original on 2022-01-05. Retrieved 2021-10-04.
  25. 25.0 25.1 WHO and UNICEF (2017) Progress on Drinking Water, Sanitation and Hygiene: 2017 Update and SDG Baselines Archived 2019-07-25 at the Wayback Machine. Geneva: World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), 2017
  26. Goel PK (2006). Water pollution: causes, effects and control (Rev. 2nd ed.). New Delhi: New Age International. ISBN 81-224-1839-2. OCLC 85857626. Archived from the original on 2022-08-12. Retrieved 2022-07-29.
  27. Olenin S, Minchin D, Daunys D (2007). "Assessment of biopollution in aquatic ecosystems". Marine Pollution Bulletin. 55 (7–9): 379–394. doi:10.1016/j.marpolbul.2007.01.010. PMID 17335857.
  28. Hartmann, Andreas; Jasechko, Scott; Gleeson, Tom; Wada, Yoshihide; Andreo, Bartolomé; Barberá, Juan Antonio; Brielmann, Heike; Bouchaou, Lhoussaine; Charlier, Jean-Baptiste; Darling, W. George; Filippini, Maria (2021-05-18). "Risk of groundwater contamination widely underestimated because of fast flow into aquifers". Proceedings of the National Academy of Sciences. 118 (20): e2024492118. doi:10.1073/pnas.2024492118. ISSN 0027-8424. PMC 8158018. PMID 33972438. Archived from the original on 2022-07-29. Retrieved 2022-07-29.
  29. United States. Clean Water Act (CWA), section 502(14), 33 U.S.C. § 1362 (14).
  30. U.S. CWA section 402(p), 33 U.S.C. § 1342(p)
  31. Scholz M (2016). "Sewage Treatment". Wetlands for Water Pollution Control. pp. 13–15. doi:10.1016/B978-0-444-63607-2.00003-4. ISBN 9780444636072.
  32. Nesaratnam ST, ed. (2014). Water Pollution Control. doi:10.1002/9781118863831. ISBN 9781118863831.
  33. Knight K (2021). "Freshwater methamphetamine pollution turns brown trout into addicts". Journal of Experimental Biology. 224 (13): jeb242971. doi:10.1242/jeb.242971. ISSN 0022-0949. Archived from the original on 2021-12-12. Retrieved 2022-07-29.
  34. De Lorenzo D (2021-06-18). "MDMA Gangs Are Literally Polluting Europe". Vice World News. Brooklyn, NY: Vice Media Group. Archived from the original on 2022-07-30. Retrieved 2022-07-29.
  35. "Governments unite to step-up reduction on global DDT reliance and add nine new chemicals under international treaty". Geneva: Stockholm Convention Secretariat. 8 May 2009. Press release. Archived from the original on 19 April 2016. Retrieved 29 July 2022.
  36. Tchobanoglous G, Burton FL, Stensel HD (2003). "Chapter 3: Analysis and Selection of Wastewater Flowrates and Constituent Loadings". Wastewater engineering: treatment and reuse (4th ed.). Boston: McGraw-Hill. ISBN 0-07-041878-0. OCLC 48053912. Archived from the original on 2022-08-12. Retrieved 2022-07-29.
  37. Arvaniti OS, Stasinakis AS (August 2015). "Review on the occurrence, fate and removal of perfluorinated compounds during wastewater treatment". The Science of the Total Environment. 524–525: 81–92. doi:10.1016/j.scitotenv.2015.04.023. PMID 25889547.
  38. Bletsou AA, Asimakopoulos AG, Stasinakis AS, Thomaidis NS, Kannan K (February 2013). "Mass loading and fate of linear and cyclic siloxanes in a wastewater treatment plant in Greece". Environmental Science & Technology. 47 (4): 1824–32. doi:10.1021/es304369b. PMID 23320453.
  39. Gatidou G, Kinyua J, van Nuijs AL, Gracia-Lor E, Castiglioni S, Covaci A, Stasinakis AS (September 2016). "Drugs of abuse and alcohol consumption among different groups of population on the Greek Island of Lesvos through sewage-based epidemiology". The Science of the Total Environment. 563–564: 633–40. doi:10.1016/j.scitotenv.2016.04.130. PMID 27236142.
  40. Gatidou G, Arvaniti OS, Stasinakis AS (April 2019). "Review on the occurrence and fate of microplastics in Sewage Treatment Plants". Journal of Hazardous Materials. 367: 504–512. doi:10.1016/j.jhazmat.2018.12.081. PMID 30620926.
  41. Walters A, ed. (2016). Nutrient Pollution From Agricultural Production: Overview, Management and a Study of Chesapeake Bay. Hauppauge, NY: Nova Science Publishers. ISBN 978-1-63485-188-6. OCLC 960163923. Archived from the original on 2021-07-25. Retrieved 2022-07-29.
  42. "Effects of Acid Rain". EPA. 2022-04-24. Archived from the original on 2022-07-22. Retrieved 2022-07-29.
  43. Kjellstrom T, Lodh M, McMichael T, Ranmuthugala G, Shrestha R, Kingsland S (2006). "Air and Water Pollution: Burden and Strategies for Control". In Jamison DT, Breman JG, Measham AR, Alleyne G, Claeson M, Evans DB, Jha P, Mills A, Musgrove P (eds.). Disease Control Priorities in Developing Countries (2nd ed.). World Bank. ISBN 978-0-8213-6179-5. PMID 21250344. Archived from the original on August 7, 2020. Retrieved 2020-04-22.
  44. "What is Acid Rain?". EPA. 2021-12-03. Archived from the original on 2020-05-23. Retrieved 2022-07-29.
  45. Sisterson DL, Liaw YP (1990-01-01). "An evaluation of lightning and corona discharge on thunderstorm air and precipitation chemistry". Journal of Atmospheric Chemistry. 10 (1): 83–96. Bibcode:1990JAtC...10...83S. doi:10.1007/BF01980039. ISSN 1573-0662. S2CID 97714446.
  46. 46.0 46.1 Caldeira K, Wickett ME (September 2003). "Oceanography: anthropogenic carbon and ocean pH". Nature. 425 (6956): 365. Bibcode:2001AGUFMOS11C0385C. doi:10.1038/425365a. PMID 14508477. S2CID 4417880.
  47. Doney SC, Fabry VJ, Feely RA, Kleypas JA (2009-01-01). "Ocean acidification: the other CO2 problem". Annual Review of Marine Science. 1 (1): 169–192. Bibcode:2009ARMS....1..169D. doi:10.1146/annurev.marine.010908.163834. PMID 21141034.
  48. For example, see Baird RB, Clesceri LS, Eaton AD, Rice EW, eds. (2012). Standard Methods for the Examination of Water and Wastewater (22nd ed.). Washington, DC: American Public Health Association. ISBN 978-0875530130. Archived from the original on 2016-02-11. Retrieved 2022-07-29.
  49. 49.0 49.1 Newton D (2008). Chemistry of the Environment. Checkmark Books. ISBN 978-0-8160-7747-2.
  50. National Rivers and Streams Assessment 2008-2009: A Collaborative Study (PDF) (Report). EPA. March 2016. EPA 841/R-16/007. Archived (PDF) from the original on 2021-07-02. Retrieved 2022-07-29.
  51. Karr JR (1981). "Assessment of biotic integrity using fish communities". Fisheries. 6 (6): 21–27. doi:10.1577/1548-8446(1981)006<0021:AOBIUF>2.0.CO;2. ISSN 1548-8446.
  52. Kelland K (2017-10-19). "Study links pollution to millions of deaths worldwide". Reuters. Archived from the original on 2021-11-08. Retrieved 2022-07-29.
  53. "China says water pollution so severe that cities could lack safe supplies". China Daily. June 7, 2005. Archived from the original on June 30, 2017. Retrieved July 29, 2022.
  54. 54.0 54.1 54.2 54.3 Jones OA, Gomes RL (2013). "Chapter 1: Chemical Pollution of the Aquatic Environment by Priority Pollutants and its Control". Pollution: Causes, Effects and Control (5th ed.). Royal Society of Chemistry. ISBN 978-1-84973-648-0. Archived from the original on 2022-01-29. Retrieved 2022-07-29.
  55. UN-Water (2018) World Water Development Report 2018: Nature-based Solutions for Water Archived 2019-09-08 at the Wayback Machine, Geneva, Switzerland
  56. Wang Y, Fan L, Jones OA, Roddick F (April 2021). "Quantification of seasonal photo-induced formation of reactive intermediates in a municipal sewage lagoon upon sunlight exposure". The Science of the Total Environment. 765: 142733. Bibcode:2021ScTEn.765n2733W. doi:10.1016/j.scitotenv.2020.142733. PMID 33572041. S2CID 225156609.
  57. Primer for Municipal Wastewater Treatment Systems (Report). EPA. 2004. p. 11. EPA 832-R-04-001. Archived from the original on 2020-03-11. Retrieved 2022-07-29.
  58. Jones OA, Green PG, Voulvoulis N, Lester JN (July 2007). "Questioning the excessive use of advanced treatment to remove organic micropollutants from wastewater". Environmental Science & Technology. 41 (14): 5085–5089. Bibcode:2007EnST...41.5085J. doi:10.1021/es0628248. PMID 17711227.
  59. Renn AM (2016-02-25). "Wasted: How to Fix America's Sewers" (PDF). New York, NY: Manhattan Institute. p. 7. Archived (PDF) from the original on 2022-01-20. Retrieved 2022-07-29.
  60. Greening CSO Plans: Planning and Modeling Green Infrastructure for Combined Sewer Overflow Control (PDF) (Report). EPA. March 2014. 832-R-14-001. Archived (PDF) from the original on 2021-03-25. Retrieved 2022-07-29.
  61. "Clean Rivers Project". District of Columbia Water and Sewer Authority. Archived from the original on 2021-09-22. Retrieved 2021-09-21.
  62. "United States and Ohio Reach Clean Water Act Settlement with City of Toledo, Ohio". EPA. 2002-08-28. Press release. Archived from the original on 2016-01-13.
  63. Tennessee Department of Environment and Conservation. Nashville, TN (2012). "Tennessee Erosion and Sediment Control Handbook." Archived 2017-07-26 at the Wayback Machine
  64. Concrete Washout (Report). Stormwater Best Management Practice. EPA. February 2012. BMP fact sheet. EPA 833-F-11-006. Archived from the original on 2017-07-29. Retrieved 2022-07-29.
  65. Mapulanga AM, Naito H (April 2019). "Effect of deforestation on access to clean drinking water". Proceedings of the National Academy of Sciences of the United States of America. 116 (17): 8249–8254. Bibcode:2019PNAS..116.8249M. doi:10.1073/pnas.1814970116. PMC 6486726. PMID 30910966.
  66. University of Basel (2020-08-24). "Climate change and land use are accelerating soil erosion by water". Science Daily. Archived from the original on 2022-06-11. Retrieved 2022-07-29.
  67. 67.0 67.1 "An Act Providing For A Comprehensive Water Quality Management And For Other Purposes". The LawPhil Project. Archived from the original on 21 September 2016. Retrieved 30 September 2016.

External links