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Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, in such a manner that negatively affects its legitimate uses.: 6 Water pollution reduces the ability of the body of water to provide the ecosystem services that it would otherwise provide. Water bodies include for example lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. In addition to damage to many species, water pollution can also lead to water-borne diseases for people. Water pollution traditionally is attributed to four sources, which provide the organization of this article:
- urban runoff including stormwater.
Water pollution can also be classified as surface water pollution (for example lakes, streams, estuaries, and parts of the ocean in marine pollution) or groundwater pollution. Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain or a wastewater treatment plant. Non-point sources are more diffuse, such as agricultural runoff. Pollution is the result of the cumulative effect over time. Supplying clean drinking water is an important ecosystem service provided by some freshwater systems, but approximately 785 million people in the world do not have access to clean drinking water because of pollution.
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".: 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.
Agriculture is a major contributor to water pollution. The use of fertilizers leads to Nutrient pollution, in which excess nutrients, usually caused by nitrogen- or phosphorus-containing compounds that are the main components. Sources of nutrient pollution include surface runoff from farm fields and pastures, discharges from septic tanks and feedlots (sewage - see below - is also high in nutrients). In addition to plant-focused agriculture, fish-farming is also a source of pollution.
Additionally, ag runoff often contains high levels of pesticides.
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.
Some industries discharge chemical wastes, including solvents and heavy metals (which are toxic) and other harmful pollutants such as nutrients. Certain industries (e.g. food processing) discharge high concentrations of biochemical oxygen demand (BOD) and oil and grease.: 180  Some industrial discharges include persistent organic pollutants such as per- and polyfluoroalkyl substances (PFAS).
Sewage typically consists of 99.9% water and 0.1% solids. 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. Lack of access to sanitation often leads to water pollution, e.g. via the practice of open defecation. Simple pit latrines may also get flooded during rain events. 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.
Sewage contributes many classes of nutrients that lead to eutrophication. It is a major source of phosphate for example.
Sewage is often contaminated with diverse compounds found in personal hygiene, cosmetics, pharmaceutical drugs] (see also drug pollution), and their metabolites Even at very low concentrations, hormones (from animal husbandry and residue from human hormonal contraception methods) and synthetic materials such as phthalates that mimic hormones in their action, can have an adverse impacts. Water pollution due to environmental persistent pharmaceutical pollutants can have wide-ranging consequences:
The environmental effect of pharmaceuticals and personal care products (PPCPs) is being investigated since at least the 1990s. PPCPs include substances used by individuals for personal health or cosmetic reasons and the products used by agribusiness to boost growth or health of livestock. More than twenty million tons of PPCPs are produced every year. The European Union has declared pharmaceutical residues with the potential of contamination of water and soil to be "priority substances".PPCPs have been detected in water bodies throughout the world. More research is needed to evaluate the risks of toxicity, persistence, and bioaccumulation, but the current state of research shows that personal care products impact over the environment and other species, such as coral reefs and fish. PPCPs encompass environmental persistent pharmaceutical pollutants (EPPPs) and are one type of persistent organic pollutants. They are not removed in conventional sewage treatment plants but require a fourth treatment stage which not many plants have.
Pathogens from sewage
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) during storm events and intensive agriculture (poorly managed livestock operations). Pathogens can produce waterborne diseases in either human or animal hosts. 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.
Urban runoff is stormwater discharged to surface waters from rooftops, roads and parking lots, and reservoirs. Often it is captured in large retaining ponds. It is subject to high suspended solids as well and elevated nitrogen and phosphorus concentrations.
Other forms of water pollution
Thermal pollution, sometimes called "thermal enrichment," is the degradation of water quality by any process that changes ambient water temperature. Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.: 375
By type of source
Sources of surface water pollution can be grouped into two categories based on their origin: point sources and nonpoint 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). 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.
Groundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. Pollution can occur from on-site sanitation systems, landfills, effluent from wastewater treatment plants, leaking sewers, petrol filling stations or from over application of fertilizers in agriculture. Pollution (or contamination) can also occur from naturally occurring contaminants, such as arsenic or fluoride. Using polluted groundwater causes hazards to public health through poisoning or the spread of disease (water-borne diseases).The pollutant often creates a contaminant plume within an aquifer. Movement of water and dispersion within the aquifer spreads the pollutant over a wider area. Its advancing boundary, often called a plume edge, can intersect with groundwater wells and surface water, such as seeps and springs, making the water supplies unsafe for humans and wildlife. The movement of the plume, called a plume front, may be analyzed through a hydrological transport model or groundwater model. Analysis of groundwater pollution may focus on soil characteristics and site geology, hydrogeology, hydrology, and the nature of the contaminants. Different mechanisms have influence on the transport of pollutants, e.g. diffusion, adsorption, precipitation, decay, in the groundwater.
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.
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),: 102 chemical oxygen demand (COD),: 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 complexity of water quality as a subject is reflected in the many types of measurements of water quality indicators. Some measurements of water quality are most accurately made on-site, because water exists in equilibrium with its surroundings. Measurements commonly made on-site and in direct contact with the water source in question include temperature, pH, dissolved oxygen, conductivity, oxygen reduction potential (ORP), turbidity, and Secchi disk depth.
Sampling of water for physical or chemical testing can be done by several methods, depending on the accuracy needed and the characteristics of the contaminant. Sampling methods include for example simple random sampling, stratified sampling, systematic and grid sampling, adaptive cluster sampling, grab samples, semi-continuous monitoring and continuous, passive sampling, remote surveillance, remote sensing, and biomonitoring. The use of passive samplers greatly reduces the cost and the need of infrastructure on the sampling location.Many contamination events are sharply restricted in time, most commonly in association with rain events. For this reason "grab" samples are often inadequate for fully quantifying contaminant levels. Scientists gathering this type of data often employ auto-sampler devices that pump increments of water at either time or discharge intervals.
The use of a biomonitor 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. 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. 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.
Control and reduction
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. 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). 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.
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.
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.
Sanitation and sewage treatment
Municipal wastewater (or sewage) can be treated by centralized sewage treatment plants, decentralized wastewater systems, nature-based solutions 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.: 182 UV light (sunlight) can be used to degrade some pollutants in waste stabilization ponds (sewage lagoons). The use of safely managed sanitation services would prevent water pollution caused by lack of access to sanitation.
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. 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.
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, but have implemented partial separation projects and green infrastructure approaches. In some cases municipalities have installed additional CSO storage facilities or expanded sewage treatment capacity.
Industrial wastewater treatment
Agricultural wastewater treatment
Agricultural wastewater treatment is a farm management agenda for controlling pollution from confined animal operations and from surface runoff that may be contaminated by chemicals in fertilizer, pesticides, animal slurry, crop residues or irrigation water. Agricultural wastewater treatment is required for continuous confined animal operations like milk and egg production. It may be performed in plants using mechanized treatment units similar to those used for industrial wastewater. Where land is available for ponds, settling basins and facultative lagoons may have lower operational costs for seasonal use conditions from breeding or harvest cycles.: 6–8 Animal slurries are usually treated by containment in anaerobic lagoons before disposal by spray or trickle application to grassland. Constructed wetlands are sometimes used to facilitate treatment of animal wastes.
Nonpoint source pollution includes sediment runoff, nutrient runoff and pesticides. Point source pollution includes animal wastes, silage liquor, milking parlour (dairy farming) wastes, slaughtering waste, vegetable washing water and firewater. Many farms generate nonpoint source pollution from surface runoff which is not controlled through a treatment plant.Farmers can install erosion controls to reduce runoff flows and retain soil on their fields.: pp. 4-95–4-96 Common techniques include contour plowing, crop mulching, crop rotation, planting perennial crops and installing riparian buffers.: pp. 4-95–4-96 Farmers can also develop and implement nutrient management plans to reduce excess application of nutrients: pp. 4-37–4-38 and reduce the potential for nutrient pollution. To minimize pesticide impacts, farmers may use Integrated Pest Management (IPM) techniques (which can include biological pest control) to maintain control over pests, reduce reliance on chemical pesticides, and protect water quality.
Management of erosion and sediment control
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. 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.
Control of urban runoff (storm water)
Effective control of urban runoff involves reducing the velocity and flow of storm water, as well as reducing pollutant discharges. Local governments use a variety of storm water management techniques to reduce the effects of urban runoff. These techniques, called best management practices for water pollution (BMPs) in some countries, may focus on water quantity control, while others focus on improving water quality, and some perform both functions.Pollution prevention practices include low impact development (LID) or green infrastructure techniques - known as Sustainable Drainage Systems (SuDS) in the UK, and Water-Sensitive Urban Design (WSUD) in Australia and the Middle East - such as the installation of green roofs and improved chemical handling (e.g. management of motor fuels & oil, fertilizers and pesticides). Runoff mitigation systems include infiltration basins, bioretention systems, constructed wetlands, retention basins and similar devices.
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, 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.
- The Clean Water Act is the primary federal law in the United States governing water pollution in surface waters. It is implemented by the U.S. Environmental Protection Agency in collaboration with states, territories, and tribes. Groundwater protection provisions are included in the Safe Drinking Water Act, Resource Conservation and Recovery Act, and the Superfund act.
- Aquatic toxicology
- Environmental impact of pesticides § Water
- Trophic state index (water quality indicator for lakes)
- Water treatment
- Water resources management
- Von Sperling, M. (2015). "Wastewater Characteristics, Treatment and Disposal". IWA Publishing. 6. doi:10.2166/9781780402086. ISBN 9781780402086.
- "Water Pollution". Environmental Health Education Program. Cambridge, MA: Harvard T.H. Chan School of Public Health. July 23, 2013. Retrieved September 18, 2021.
- Eckenfelder, W. Wesley (2000). "Water, Pollution". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.1615121205031105.a01. ISBN 9780471484943.
- Moss, Brian (2008). "Water Pollution by Agriculture". Phil. Trans. R. Soc. Lond. B. 363 (1491): 659–666. doi:10.1098/rstb.2007.2176. PMC 2610176. PMID 17666391.
- "Global Water, Sanitation and Hygiene". Global WASH Fast Facts. Atlanta, GA: US Centers for Disease Control and Prevention. April 1, 2021.
- Arlene., Walters (2016). Nutrient Pollution From Agricultural Production. Nova Science Publishers, Inc. ISBN 978-1-63485-188-6. OCLC 960163923.
- "Alumina Production". London: International Aluminum Institute. October 26, 2021.
- "Chapter 3: Analysis and Selection of Wastewater Flowrates and Constituent Loadings". Wastewater engineering: treatment and reuse. George Tchobanoglous, Franklin L. Burton, H. David Stensel, Metcalf & Eddy (4th ed.). Boston: McGraw-Hill. 2003. ISBN 0-07-041878-0. OCLC 48053912.CS1 maint: others (link)
- Laws, Edward A. (2018). Aquatic Pollution: An Introductory Text (4th ed.). Hoboken, NJ: John Wiley & Sons. ISBN 9781119304500.
- Johnson, Mark S.; Buck, Robert C.; Cousins, Ian T.; Weis, Christopher P.; Fenton, Suzanne E. (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. ISSN 0730-7268. PMC 8387100. PMID 32452041.
- Sinclair, Georgia M.; Long, Sara M.; Jone s, Oliver A.H. (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.
- Scholz, Miklas (2016). "Sewage Treatment". Wetlands for Water Pollution Control. pp. 13–15. doi:10.1016/B978-0-444-63607-2.00003-4. ISBN 9780444636072.
- WHO and UNICEF (2017) Progress on Drinking Water, Sanitation and Hygiene: 2017 Update and SDG Baselines. Geneva: World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), 2017
- Nesaratnam, Suresh T, ed. (2014). Water Pollution Control. doi:10.1002/9781118863831. ISBN 9781118863831.
- Knight, Kathryn (2021). "Freshwater methamphetamine pollution turns brown trout into addicts". Journal of Experimental Biology. 224 (13): jeb242971. doi:10.1242/jeb.242971. ISSN 0022-0949.
- De Lorenzo, Daniela (June 18, 2021). "MDMA Gangs Are Literally Polluting Europe". Vice World News. Brooklyn, NY: Vice Media Group.
- "Environment Agency (archive) – Persistent, bioaccumulative and toxic PBT substances". Environment Agency (UK). Archived from the original on August 4, 2006. Retrieved November 14, 2012.
- Natural Environmental Research Council – River sewage pollution found to be disrupting fish hormones. Planetearth.nerc.ac.uk. Retrieved on 2012-12-19.
- "Endocrine Disruption Found in Fish Exposed to Municipal Wastewater". Reston, VA: US Geological Survey. Archived from the original on October 15, 2011. Retrieved November 14, 2012.
- Wang J, Wang S (November 2016). "Removal of pharmaceuticals and personal care products (PPCPs) from wastewater: A review". Journal of Environmental Management. 182: 620–640. doi:10.1016/j.jenvman.2016.07.049. PMID 27552641.
- Shinn H (2019). "The Effects of Ultraviolet Filters and Sunscreen on Corals and Aquatic Ecosystems: Bibliography". NOAA Central Library. doi:10.25923/hhrp-xq11. Cite journal requires
- Downs CA, Kramarsky-Winter E, Segal R, Fauth J, Knutson S, Bronstein O, et al. (February 2016). "Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands". Archives of Environmental Contamination and Toxicology. 70 (2): 265–88. doi:10.1007/s00244-015-0227-7. PMID 26487337. S2CID 4243494.
- Downs CA, Kramarsky-Winter E, Fauth JE, Segal R, Bronstein O, Jeger R, et al. (March 2014). "Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata". Ecotoxicology. 23 (2): 175–91. doi:10.1007/s10646-013-1161-y. PMID 24352829. S2CID 1505199.
- Niemuth NJ, Klaper RD (September 2015). "Emerging wastewater contaminant metformin causes intersex and reduced fecundity in fish". Chemosphere. 135: 38–45. Bibcode:2015Chmsp.135...38N. doi:10.1016/j.chemosphere.2015.03.060. PMID 25898388.
- Larsson DG, Adolfsson-Erici M, Parkkonen J, Pettersson M, Berg AH, Olsson PE, Förlin L (April 1, 1999). "Ethinyloestradiol — an undesired fish contraceptive?". Aquatic Toxicology. 45 (2): 91–97. doi:10.1016/S0166-445X(98)00112-X. ISSN 0166-445X.
- Report to Congress: Impacts and Control of CSOs and SSOs (Report). EPA. August 2004. EPA 833-R-04-001.
- Pollution: Causes, effects, and control. Roy M. Harrison (5th ed.). Cambridge, UK: Royal Society of Chemistry. 2013. ISBN 978-1-78262-560-5. OCLC 1007100256.CS1 maint: others (link)
- 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.
- Kelland, Kate (October 19, 2017). "Study links pollution to millions of deaths worldwide". Reuters.
- Olenin, Sergej; Minchin, Dan; Daunys, Darius (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.
- United States. Clean Water Act (CWA), section 502(14), 33 U.S.C. § 1362 (14).
- U.S. CWA section 402(p), 33 U.S.C. § 1342(p)
- "Basic Information about Nonpoint Source Pollution". Washington, DC: US Environmental Protection Agency (EPA). October 7, 2020.
- Michael, Adelana, Segun (2014). Groundwater : Hydrogeochemistry, Environmental Impacts and Management Practices. Nova Science Publishers, Inc. ISBN 978-1-63321-791-1. OCLC 915416488.
- For example, see Baird, Rodger B.; Clesceri, Leonore S.; Eaton, Andrew D.; et al., eds. (2012). Standard Methods for the Examination of Water and Wastewater (22nd ed.). Washington, DC: American Public Health Association. ISBN 978-0875530130.
- Newton, David (2008). Chemistry of the Environment. Checkmark Books. ISBN 978-0-8160-7747-2.
- "Sampling - KFUPM School , nature is us - Forums - Tunza Eco Generation". tunza.eco-generation.org. Retrieved September 19, 2021.
- U.S. Environmental Protection Agency. Office of Water and Office of Research and Development. (March 2016). "National Rivers and Streams Assessment 2008-2009: A Collaborative Study" (PDF). Washington D.C.
- Karr, James R. (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.
- "China says water pollution so severe that cities could lack safe supplies". Chinadaily.com.cn. June 7, 2005.
- Jones, Oliver A. H.; Gomes, Rachel L. (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.
- UN-Water (2018) World Water Development Report 2018: Nature-based Solutions for Water, Geneva, Switzerland
- Wang, Yufei; Fan, Linhua; Jones, Oliver A.H.; Roddick, Felicity (2021). "Quantification of seasonal photo-induced formation of reactive intermediates in a municipal sewage lagoon upon sunlight exposure". Science of the Total Environment. 765: 142733. Bibcode:2021ScTEn.765n2733W. doi:10.1016/j.scitotenv.2020.142733. PMID 33572041. S2CID 225156609.
- Primer for Municipal Wastewater Treatment Systems (Report). EPA. 2004. p. 11. EPA 832-R-04-001.
- Jones, Oliver A. H.; Green, Pat G .; Voulvoulis, Nikolaos; Lester, John N. (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.
- Renn, Aaron M. (February 25, 2016). "Wasted: How to Fix America's Sewers" (PDF). New York, NY: Manhattan Institute. p. 7.
- Greening CSO Plans: Planning and Modeling Green Infrastructure for Combined Sewer Overflow Control (PDF) (Report). EPA. March 2014. 832-R-14-001.
- "Clean Rivers Project". District of Columbia Water and Sewer Authority. Retrieved September 21, 2021.
- "United States and Ohio Reach Clean Water Act Settlement with City of Toledo, Ohio". EPA. August 28, 2002. Press release. Archived from the original on January 13, 2016.
- Tchobanoglous, G., Burton, F.L., and Stensel, H.D. (2003). Wastewater Engineering (Treatment Disposal Reuse) / Metcalf & Eddy, Inc (4th ed.). McGraw-Hill Book Company. ISBN 0-07-041878-0.CS1 maint: multiple names: authors list (link)
- "Chapter 3: Analysis and Selection of Wastewater Flowrates and Constituent Loadings". Wastewater engineering: treatment and reuse. George Tchobanoglous, Franklin L. Burton, H. David Stensel, Metcalf & Eddy (4th ed.). Boston: McGraw-Hill. 2003. ISBN 0-07-041878-0. OCLC 48053912.CS1 maint: others (link)
- Von Sperling, M. (2015). "Wastewater Characteristics, Treatment and Disposal". Water Intelligence Online. 6: 9781780402086. doi:10.2166/9781780402086. ISSN 1476-1777.
- Reed, Sherwood C. (1988). Natural systems for waste management and treatment. E. Joe Middlebrooks, Ronald W. Crites. New York: McGraw-Hill. ISBN 0-07-051521-2. OCLC 16087827.
- "Erosion". Washington, DC: US Natural Resources Conservation Service. Retrieved November 19, 2020.
- National Management Measures to Control Nonpoint Source Pollution from Agriculture (Report). EPA. July 2003. EPA 841-B-03-004.
- U.S. Natural Resources Conservation Service (NRCS). Washington, DC. "National Conservation Practice Standards." National Handbook of Conservation Practices. Accessed 2015-10-02.
- "Integrated Pest Management Principles". Pest Control and Pesticide Safety for Consumers. EPA. June 27, 2017.
- Tennessee Department of Environment and Conservation. Nashville, TN (2012). "Tennessee Erosion and Sediment Control Handbook."
- Concrete Washout (Report). Stormwater Best Management Practice. EPA. February 2012. BMP fact sheet. EPA 833-F-11-006.
- Mapulanga, Annie Mwayi; Naito, Hisahiro (2019). "Effect of deforestation on access to clean drinking water". Proceedings of the National Academy of Sciences. 116 (17): 8249–8254. Bibcode:2019PNAS..116.8249M. doi:10.1073/pnas.1814970116. ISSN 0027-8424. PMC 6486726. PMID 30910966.
- "Climate change and land use are accelerating soil erosion by water". www.preventionweb.net. Retrieved August 4, 2021.
- "Ch. 5: Description and Performance of Storm Water Best Management Practices". Preliminary Data Summary of Urban Storm Water Best Management Practices (Report). Washington, DC: United States Environmental Protection Agency (EPA). August 1999. EPA-821-R-99-012.
- Protecting Water Quality from Urban Runoff (Report). EPA. February 2003. EPA 841-F-03-003.
- "Low Impact Development and Other Green Design Strategies". National Pollutant Discharge Elimination System. EPA. 2014. Archived from the original on February 19, 2015.
- California Stormwater Quality Association. Menlo Park, CA. "Stormwater Best Management Practice (BMP) Handbooks." 2003.
- New Jersey Department of Environmental Protection. Trenton, NJ. "New Jersey Stormwater Best Management Practices Manual." April 2004.
- "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.
- United States. Clean Water Act. 33 U.S.C. § 1251 et seq. Pub.L. 92–500. Approved October 18, 1972.
- Jim Hanlon, Mike Cook, Mike Quigley, Bob Wayland (March 2016). "Water Quality: A Half Century of Progress" (PDF). EPA Alumni Association.CS1 maint: uses authors parameter (link)
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