Water pollution in the United States

Topsoil runoff from farm, central Iowa, USA (2011).

Since the 1960s, water quality in surface water bodies in the United States has generally improved, due to the implementation of the 1972 Clean Water Act. However, many water bodies are still being polluted from one or more categories of sources, which may include agriculture, industry, or urban runoff.


Dead zone in the Gulf of Mexico.

Since the passage of the 1972 Clean Water Act (CWA), the levels of water pollution in the United States generally have experienced a dramatic decrease. The law has resulted in much cleaner waterways than before the law was implemented.[1]

However, more than half of U.S. stream and river miles continue to violate water quality standards. Surveys of lakes, ponds and reservoirs indicated that about 70 percent were impaired (measured on a surface area basis), and a little more than 70 percent of the nation’s coastlines, and 90 percent of the surveyed ocean and near coastal areas were also impaired.[2]

Agriculture, industry, communities (typically through urban runoff) and other sources continue to discharge waste into surface waters nationwide, and many of these waters are drinking water sources. In many watersheds nutrient pollution (excess nitrogen and phosphorus) has become a major problem.[3]

It is argued in a 2008 paper that the CWA has made extremely positive contributions to the environment, but that the law does not address some aspects of pollution well, or at all, and that Congress should revise or expand the law to address these problems.[4]

Municipal sewageEdit

Sewage pollution, which had been a major national environmental issue into the 1970s, has largely been addressed through widespread public investment in infrastructure and enforcement of CWA requirements.[1]

Domestic sewage became a widespread problem with the onset of the industrial revolution in the 19th century, population growth and increasing urbanization. Through the early 20th century, most communities had no sewage treatment plants. Many cities built sewer pipes which carried the sewage to a nearby river or coastal area, but without any treatment of the wastes. The first plants that were built in the late 19th and early 20th centuries typically did not fully treat the wastes.[5]

Sewage plant upgradesEdit

In the 1972 CWA, Congress created a major public works financing program for building and upgrading sewage treatment plants. This grant program was transitioned to a low-interest loan program in the 1987 amendments to the act.[6] Ideally, the municipal wastewater treatment process comprises three stages:

A tertiary treatment facility is typically four times more expensive to operate, compared to a secondary treatment system, so it is used only when absolutely necessary. Today over 75% of the population is served by more than 16,000 municipal sewage plants, and most treatment plants in the U.S. include secondary treatment components. Federal regulations require secondary treatment plants to remove 85% or more of the biochemical oxygen demand (BOD) and suspended solids.[8]:4 [9]

The methods of municipal sewage treatment in the United States produce a large amount of bacteria since the soluble organic matter is converted to biomass, which is also known as biosolids and these are applied to soils as fertilizers or source of water in the case of water effluents to improve soil productivity or enhance revegetation.[10] The land application of treated biosolids and effluent, which started to increase after the restriction to ocean dumping, helps reduce pollution particularly in areas where the surface water is not capable of assimilating elements such as nitrogen and phosphorus. The excessive amount of these chemical elements lead to pollution.[10]

Remaining problemsEdit

With the widespread implementation of secondary treatment technology, water quality has greatly improved in many watersheds nationwide.[1] However, many municipal plants are being challenged to confront some significant remaining problems:

  • Many cities have combined sewers, which can cause discharges of untreated sewage during large storms.[8]:7
  • Many plants discharge nutrients (nitrogen and phosphorus), which are only partially controlled by secondary treatment processes.[8]:8 Some of these plants have additional systems to treat nutrients (tertiary treatment), but additional control for nutrients is a continuing concern in communities nationwide.[11]

Urban runoffEdit

Parking lots, roads and buildings are major sources of urban runoff

A growing body of water research during the late 1970s and 1980s indicated that stormwater runoff was a significant cause of water quality impairment in many parts of the US.[12] Increased land development throughout the country—in both cities and suburbs—has led to an increase in impervious surfaces (parking lots, roads, buildings, compacted soil), which generates increased surface runoff during wet weather. Congress responded to the stormwater problem with the enactment of the Water Quality Act of 1987. The law defines industrial stormwater dischargers and municipal separate storm sewer systems (often called "MS4") as point sources, and requires these facilities to obtain discharge permits under the National Pollutant Discharge Elimination System (NPDES).[13]

Map of municipal separate storm sewer systems

To implement the 1987 law, thousands of local governments established stormwater management programs. Each regulated municipality developed standard program elements as required by EPA regulations:

About 855 large municipal stormwater systems (serving populations of 100,000 or more), and 6,695 small systems are regulated by the permit system.[16]

While the industrial and MS4 facilities are now regulated through NPDES permits, stormwater management in communities is an ongoing challenge. A 2008 report by the United States National Research Council identified urban runoff as a leading source of water quality problems: "Stormwater runoff from the built environment remains one of the great challenges of modern water pollution control, as this source of contamination is a principal contributor to water quality impairment of waterbodies nationwide. In addition to entrainment of chemical and microbial contaminants as stormwater runs over roads, rooftops, and compacted land, stormwater discharge poses a physical hazard to aquatic habitats and stream function, owing to the increase in water velocity and volume that inevitably result on a watershed scale as many individually managed sources are combined."[17]

As of 2018, EPA and state water quality agencies have estimated that urban runoff is a probable source of impairment for at least 49,000 miles (79,000 km) of rivers and streams; 759,000 acres (3,070 km2) of lakes, reservoirs and ponds; and 316 miles (509 km) of coastal shoreline.[18]

Industrial pollutionEdit

Some narratives based on observations of industrial waste discharged to certain rivers and harbors were first reported in the 1870s, as the industrial revolution expanded throughout the United States and its environmental impacts were observed more frequently.[19][20]

Growth of industrialization and industrial wasteEdit

Historical accounts of early industrial activity in the US provide a general description of the kinds of waste generated. Mining operations (coal, metals, minerals), iron forges and blast furnaces were some of the early industries in the U.S. that generated waste. In the late 18th and early 19th centuries, wastes from mining operations entered rivers and streams, and iron bloomeries and furnaces used water for cooling.[21]:27, 32-33, 53 These industries were relatively small businesses generating small amounts of product,[22] and the wastes they discharged to rivers and streams were proportionately small and dilute, as compared to the factories that would be established later in the 19th century. In the early 19th century, the introduction of steam engines in both the mining and manufacturing sectors (such as textiles) greatly expanded productivity, and increased use of the engines generated larger volumes of heated water (thermal pollution).[21]:52-53 The productivity gains, along with the introduction of railroads in the 1830s and 1840s--which increased the overall demand for coal and minerals--led to additional generation of wastes.[23][24]:68-69

The volumes and concentrations of industrial wastes increased significantly in the mid-19th century in multiple business sectors, including mining. Mining wastes were increasing, not only from coal and mineral mines in the east and south, but from mining of gold, silver and other metals in the newly-developing west.[24]:92-95 [25]

The onset of the second industrial revolution in the mid-to-late 19th century, introduced new heavy industries in the US, generating larger volumes and new kinds of wastes. These industries included:

Industrial expansion continued into the 20th century, including large-scale expansion of paper products manufacturing, which produced additional types and quantities of wastes.[27][28]

Water quality problems caused by industry were not a well-known nor well-understood problem during the 19th century,[29] The lack of response to industrial pollution at that time can be explained by two principal reasons:

  1. Focus on disease transmitted through water systems. Compared to industrial wastewater, the problems of contaminated drinking water and other disease pathways related to untreated sewage presented a greater problem to society. Public health experts and others in the scientific community were focusing their attention on the problems of untreated sewage and its effect on drinking water supplies and public health generally. The rapid urbanization of American cities had led to construction of city sewer pipes. The sewers carried the waste away from the population centers, but ultimately discharged the domestic waste into rivers and coastal areas without treatment. The potential effect of sewage on local drinking water supplies stimulated great concern about threats to public health from diseases. This concern, repeated in city after city, led to calls for construction of sewage treatment plants, which eventually began to appear at the beginning of the 20th century.[30]:1060
  2. Limited scientific techniques. To the extent that anyone was interested in measuring industrial pollution, there was a lack of validated scientific test methods for the various polluting chemicals. The impacts of pollution on the environment generally (i.e. to wildlife and ecosystems) were poorly understood. The discipline of analytical chemistry was in its early stages and the academic field of environmental science had not yet been developed.

The majority of the US scientific community essentially did not focus their attention on the problems of industrial wastewater until well into the 20th century. In the industrial sector, the most visible wastewater problem was frequent oil spills in rivers and harbors. Thus the principal U.S. efforts in water quality improvement during the early industrial era led communities to focus on building drinking water treatment and sewage treatment facilities.[30]:1060

During the late 19th century, there was little federal government attention paid to what were considered to be local environmental and health problems. The only federal legislation to address water pollution during this era was the Rivers and Harbors Act of 1899.[31] In the 1899 law, Congress prohibited the dumping of "refuse"—debris that interfered with navigation—but other forms of pollution (e.g. sewage, food waste, chemical waste, oil spills) were not addressed in the law.[32]

A government hydrologist, in a 1905 paper, listed several industries that generated significant amounts of wastewater, including distilleries, pulp and paper mills, wool processing, ironworks and coal mines. The paper identified pollutants of concern and explained the chemistry of the discharges, but did not quantify the concentration or extent of pollution. The author acknowledged the focus of his contemporaries on pathogens and their impacts on public health, but explained that organic chemical waste from industrial sources provided a medium for the growth of bacteria.[33]

Industrial development in the US expanded to support the war effort during World War I:

All of these manufacturing processes generated wastes. Oil production and shipments increased, leading to more frequent oil spills. In 1924, to address oil spills in harbors, Congress passed the Oil Pollution Act. The law provided for penalties in the event of oil spills, but they were applicable only to vessels in coastal waters.[35]

In the 1930s-1940s review boards were created in several states to study water pollution (including industrial wastes) and make recommendations.[28][36][37] These agencies supported voluntary measures to be implemented by industry and did not issue regulations to control wastewater discharges.[30]:1061

Voluntary treatment standardsEdit

The American Public Health Association (APHA), a professional organization, issued recommended drinking water standards for lead, copper and zinc in 1925. While these standards were applicable to municipal drinking water systems, they provided a basis for developing industrial pollution standards.[30] A few industry sectors, such as petroleum refineries, began publishing voluntary standards for treating industrial wastewater in the 1930s.[38][39]

After World War IIEdit

During the Post–World War II economic expansion there was tremendous growth in the chemicals industry, particularly petrochemicals. Many new plastics and synthetic fiber products were developed, along with increases in the types and quantities of agricultural chemicals, both fertilizers and pesticides.[40] Pollution discharges from chemical plants continued, and incidents such as the contamination of the James River (Virginia) from pesticide dumping in the late 1960s received significant public attention.[41] Pollution from other industries continued as well, including the mining industry, with the Reserve Mining Company pollution of Lake Superior being one of the most notorious cases.[42] The economic growth required expansion of the nation's electrical capacity. Many new power plants were built or expanded,[43] and there was continued development of fossil fuels (coal, oil, natural gas) to supply the plants.

Agricultural pollutionEdit

Pollution incidentsEdit

Polluted water bodies (partial list)Edit

See alsoEdit


  1. ^ a b c Water Pollution Control: 25 years of Progress and Challenges for the New Millennium (Report). Washington, D.C.: United States Environmental Protection Agency (EPA). June 1998. EPA 833-F-98-003.
  2. ^ "National Summary of State Information". Water Quality Assessment and TMDL Information. EPA. Retrieved 2018-05-21.
  3. ^ "Nutrient Pollution: The Problem". EPA. 2017-03-10.
  4. ^ Andreen, William L.; Jones, Shana C. (July 2008). The Clean Water Act: A Blueprint For Reform (PDF) (Report). Edgewater, MD: Center for Progressive Reform. CPR White Paper #802.
  5. ^ Metcalf & Eddy, Inc. (1972). Wastewater Engineering. New York: McGraw–Hill. pp. 4–6.
  6. ^ Copeland, Claudia (2012-04-05). Water Infrastructure Financing: History of EPA Appropriations (PDF) (Report). U.S. Congressional Research Service.
  7. ^ Smith, Zachary (2017). The Environmental Policy Paradox. Routledge. ISBN 9781317226628.
  8. ^ a b c Primer for Municipal Wastewater Treatment Systems (Report). Washington, D.C.: EPA. 2004. EPA 832-R-04-001.
  9. ^ EPA. "Secondary Treatment Regulation." Code of Federal Regulations, 40 C.F.R. 133.102
  10. ^ a b Gerba, Charles; Brusseau, Mark (2006). Environmental and Pollution Science. Burlington, MA: Academic Press. p. 452. ISBN 9780125515030.
  11. ^ "Sources and Solutions: Wastewater". Nutrient Pollution. EPA. 2018-01-30.
  12. ^ For example, see the Nationwide Urban Runoff Program (1979-83).
  13. ^ United States. Water Quality Act of 1987, Pub.L. 100–4. February 4, 1987. Added Clean Water Act section 402(p), 33 U.S.C. § 1342(p).
  14. ^ "Stormwater Discharges from Municipal Sources". NPDES. EPA. 2018-04-04.
  15. ^ EPA. NPDES Program Regulations. §122.26: Storm water discharges. §122.34: Permit requirements for regulated small MS4 permits. Code of Federal Regulations, 40 C.F.R. 122.26 and 40 C.F.R. 122.34.
  16. ^ "Overview". NPDES / Stormwater Discharges from Municipal Sources. EPA. 2018-04-04.
  17. ^ National Research Council (United States) (2009). Urban Stormwater Management in the United States (Report). Washington, D.C.: National Academies Press. p. vii. doi:10.17226/12465. ISBN 978-0-309-12539-0.
  18. ^ "National Probable Sources Contributing to Impairments". National Summary of State Information. EPA. Retrieved 2018-11-30.
  19. ^ Kirkwood, J.P. (1970) [First published 1876]. A Special Report on the Pollution of River Waters. Annual Report, Massachusetts State Board of Health (Report) (Reprint ed.). New York: Arno Press.
  20. ^ Leeds, Albert R. (1887-05-01). "The Monstrous Pollution of the Water Supply of Jersey City and Newark". J. Am. Chem. Soc. 9 (5): 81–97. doi:10.1021/ja02128a010.
  21. ^ a b Gordon, Robert B. (2001). American Iron, 1607-1900. JHU Press. ISBN 0801868165.
  22. ^ Mulholland, James A. (1981). History of Metals in Colonial America. University of Alabama Press. ISBN 0817300538.
  23. ^ a b Knowles, Anne Kelly (2013). Mastering Iron: The Struggle to Modernize an American Industry, 1800-1868. University of Chicago Press. p. 76. ISBN 978-0226448596.
  24. ^ a b Merchant, Carolyn (2007). American Environmental History: An Introduction. Columbia University Press. ISBN 978-0231140355.
  25. ^ Integrated Investigations of Environmental Effects of Historical Mining in the Basin and Boulder Mining Districts, Boulder River Watershed, Jefferson County, Montana (Report). Reston, VA: U.S. Geological Survey. 2004. Professional Paper 1652.
  26. ^ "Edwin Drake: Oil Drilling". Who Made America?. Public Broadcasting Service (PBS). Retrieved 2019-06-01.
  27. ^ McFarlane, Wallace S. (April 2012). "Defining a Nuisance: Pollution, Science, and Environmental Politics on Maine's Androscoggin River". Environmental History. 17 (2): 307–335. doi:10.1093/envhis/ems019.
  28. ^ a b Wisconsin State Committee on Water Pollution and State Board of Health (1939). Investigation of the Pollution of the Fox and East Rivers and of Green Bay in the Vicinity of the City of Green Bay (Report). Madison, WI: Wisconsin State Board of Health.
  29. ^ "In 1881, Cleveland’s mayor considered the Cuyahoga [River] 'an open sewer through the center of the city' but little was done to address such concerns." Adler, Jonathan H. (2002). "Fables of the Cuyahoga - Reconstructing a History of Environmental Protection". Fordham Envtl. L. Rev. 14 (89): 99.
  30. ^ a b c d Tarr, Joel A. (September 1985). "Industrial Wastes and Public Health: Some Historical Notes, Part 1, 1876-1932". American Journal of Public Health. 75 (9): 1059–1067. doi:10.2105/AJPH.75.9.1059. PMC 1646324. PMID 3895993.
  31. ^ United States. Rivers and Harbors Appropriation Act of 1899. Ch. 425, Sec. 9, 30 Stat. 1151. 33 U.S.C. § 407. Approved March 3, 1899.
  32. ^ Franz, Andrew (Summer 2010). "Crimes Against Water: The Rivers and Harbors Act of 1899". Tulane Environmental Law Journal. 23 (2): 255–278. JSTOR 43294085.
  33. ^ Leighton, Marshall O. (1905). "Industrial wastes and their sanitary significance". Public Health Papers and Reports. American Public Health Association. 31 (Pt 1) (Pt 1): 29–40. PMC 2222510. PMID 19601226.
  34. ^ Smith, Jr., John Kenly (2016). "Chemical Industry". Encyclopedia of Greater Philadelphia. Camden, NJ: Rutgers University, Department of History.
  35. ^ United States. Oil Pollution Act of 1924. Pub.L. 68–238, June 7, 1924.
  36. ^ "Interstate Environmental Commission: Our History". Staten Island, NY: Interstate Environmental Commission (Connecticut, New Jersey, New York). Retrieved 2019-07-04.
  37. ^ "About ICPRB". Rockville, MD: Interstate Commission on the Potomac River Basin (District of Columbia, Maryland, Pennsylvania, Virginia, West Virginia). Retrieved 2019-07-04.
  38. ^ Disposal of Refinery Wastes. New York: American Petroleum Institute. 1931.
  39. ^ Ferguson, H.F. (January 1935). "Oil Pollution and Refinery Wastes". Sewage Works Journal. 7 (1): 104–115. JSTOR 25028499.
  40. ^ Aftalion, Fred (2001). "Chapter 5. World War II and Its Consequences for World Chemicals". A History of the International Chemical Industry. Philadelphia, PA: Chemical Heritage Foundation. ISBN 0941901297.
  41. ^ Zygmunt, J.B.; et al. (2016). "2.A. A Milestone Pollution Case in Historical Context: Allied Chemical & Its Kepone Pesticide". Environmental Law and Policy: Nature, Law, and Society. New York: Wolters Kluwer Law & Business. ISBN 1454880147.
  42. ^ Manuel, Jeffrey T. (2017). "7. Efficiency, Economics and Environmentalism: Low-Grade Iron Ore Mining in the Lake Superior District, 1913-2010". In McNeill, John R.; Vrtis, George (eds.). Mining North America: An Environmental History Since 1522. Oakland, CA: University of California Press. ISBN 0520279174.
  43. ^ Hirsh, Richard F. (September 2002). "Post World War II "Golden Years"". Powering The Past: A Look Back. Washington, D.C.: National Museum of American History, Smithsonian Institution.
  44. ^ "Report: Ohio River most polluted in U.S." Pittsburgh Business Times. March 23, 2012. Retrieved April 24, 2012.
  45. ^ Coleman, Dash. "Report calls Savannah River third most toxic in America".

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