Water pollution in the United States
[2][3] In the early 20th century, communities began to install drinking water treatment systems, but control of the principal pollution sources—domestic sewage, industry, and agriculture—was not effectively regulated in the US until the 1970s.
Other causes of contamination in groundwater includes gasoline, oil, road salts, septic tank waste, or leakage from landfills.
Point sources could include leaking septic tanks, oil spills, dumping of waste, or wastewater treatment facilities.
[3]: 48–50 The first wastewater treatment plants were built in the late 19th and early 20th centuries in the United States and typically didn't fully treat the waste.
[21] The extensive construction of new and upgraded sewage treatment systems following the passage of the 1972 Clean Water Act has greatly reduced the impacts of municipal discharges.
[25] Research on stormwater pollution continues in the 21st century, with findings that urban runoff is an ongoing source of water quality problems nationwide.
Typical runoff pollutants include gasoline, oil and other motor vehicle fluids; metals; fertilizers; pesticides and other chemicals.
[29][30] Industrial wastes contribute toxic pollutants and chemicals and can have detrimental ecosystem and public health impacts if discharged directly into surface water.
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.
[40] In 2015 the EPA found that fossil-fuel power stations, particularly coal-fired plants were the largest contributors of industrial water pollution.
[41] EPA found instances where power plants discharged toxic pollutants, such as mercury, arsenic, and lead into surface waters.
[43] Based on a report of 21,393 industrial and commercial facilities subject to the EPA Toxics Release Inventory (TRI) system, discharges of toxic pollutants in 2019 totaled about 200 million pounds (91 kt), a decrease of 38 million pounds (17 kt) (16% reduction) from 2007, mostly due to reduced nitrate discharges.
)[44] Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemical compounds that pose significant health and environmental concerns.
[57] In addition, nutria burrow into levees and other flood control systems, weakening them, as well as eroding the banks of streams and rivers.
[48] Buffers are small strips of land covered in plants that are able to remove pollutants such as nitrogen, phosphorus, and sediment prior to discharge in a water body.
[74] The most common and efficient control method on agricultural land is crop management, which increases soil cover and stabilizes slopes to prevent erosion.
[74] Without proper soil stabilization techniques, rainfall can cause large quantities of sediment to be washed away into waterways, creating issues with sunlight penetration and visibility.
The incident began on April 20, 2010, when a semi-submersible BP oil rig exploded in the Gulf of Mexico about 41 miles off of the coast of Louisiana.
[80] In addition, the frequency of hurricanes in the Gulf makes the effects of long-term exposure on humans more applicable, as these storms are capable of carrying crude oil over miles of ocean towards the shore.
According to a research article from LSU, “damages to those living in the presence of crude oil the past 10 years are likely permanent, as chronic exposure leads to increased cancer risks, cardiovascular issues, and respiratory problems.” Oil exposure and its respiratory effects were also analyzed in a study on the Coast Guard personnel deployed to help clean up the spill.
Without the natural cleaning mechanism that flowing water provides, oil is able to coat marsh vegetation for longer periods of time, ruining nurseries that then impact a host of interconnected species.
[87] On the other hand, a 2015 article from NPR exhibited how fishing cities along the Gulf Coast are still feeling harmful effects of the oil spill.
[89] The families attributed the leukemia to the town's polluted drinking water which had been contaminated over 150 years of industry, most notably the toxic compounds used by leather factories in the area.
On December 22, 2008, a dike ruptured on the Kingston Fossil Plant in Roane County, Tennessee and released 1.1 billion gallons of coal fly ash slurry into the Emory River.
[96] In the early 20th century the United States Public Health Service (PHS) began to investigate incidents of waterborne disease and drinking water contamination.
However these industrial sources were not extensively studied at that time, and the principal focus of most public health professionals was on biological contamination of water from untreated sewage.
[93]: 1062 In the 1920s there was agreement among water scientists that pollution from acid mine drainage and coke manufacturing (which generates phenols) was the major industrial waste problem.
In 1924 a voluntary agreement was formulated between the US Surgeon General, several state agencies and manufacturers in the Ohio River valley to control phenol discharges from coke facilities.
[109] Some economists questioned whether the 1972 law was delivering the promised results of cleaner rivers and lakes, and whether benefits exceeded the costs to society.
