Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for human consumption, but water purification may also be carried out for a variety of other purposes, including medical, pharmacological, chemical, and industrial applications. The history of water purification includes a wide variety of methods. The methods used include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination; and the use of electromagnetic radiation such as ultraviolet light.
Microfiltration is a type of physical filtration process where a contaminated fluid is passed through a special pore-sized membrane filter to separate microorganisms and suspended particles from process liquid. It is commonly used in conjunction with various other separation processes such as ultrafiltration and reverse osmosis to provide a product stream which is free of undesired contaminants.
A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation, accessible drinking water, public and private aquariums, and the safe use of ponds and swimming pools.
Slow sand filters are used in water purification for treating raw water to produce a potable product. They are typically 1–2 m (3.3–6.6 ft) deep, can be rectangular or cylindrical in cross section and are used primarily to treat surface water. The length and breadth of the tanks are determined by the flow rate desired for the filters, which typically have a loading rate of 200–400 litres (0.20–0.40 m3) per square metre per hour.
The Louisville Water Company is a water company based in Louisville, Kentucky.
American Water Works Association (AWWA) is an international non-profit, scientific and educational association founded to improve water quality and supply. Established in 1881, it is a lobbying organization representing a membership of around 50,000 members worldwide.
A combination of aqueducts, reservoirs, and tunnels supplies fresh water to New York City. With three major water systems stretching up to 125 miles (201 km) away from the city, its water supply system is one of the most extensive municipal water systems in the world.
Water supply and sanitation in the United States involves a number of issues including water scarcity, pollution, a backlog of investment, concerns about the affordability of water for the poorest, and a rapidly retiring workforce. Increased variability and intensity of rainfall as a result of climate change is expected to produce both more severe droughts and flooding, with potentially serious consequences for water supply and for pollution from combined sewer overflows. Droughts are likely to particularly affect the 66 percent of Americans whose communities depend on surface water. As for drinking water quality, there are concerns about disinfection by-products, lead, perchlorates, PFAS and pharmaceutical substances, but generally drinking water quality in the U.S. is good.
Water For People was founded in 1991 by the American Water Works Association (AWWA) as a response to the increasing water scarcity in developing countries. It is a nonprofit international development organization that helps people in rural parts of developing countries achieve greater access to drinkable and potable water and sanitation facilities. It works to accomplish the United Nations' 6th Sustainable Development Goal: availability of clean water and sanitation and comprehensive monitoring of freshwater facilities for the progression of human health. They seek to address the issue of nonexistent and suboptimal water and sanitation facilities across less-developed countries. With developing locally sustainable drinking water resources and sanitation facilities, Water For People also works to bring health and hygiene education programs to local districts. The non-governmental organization also works to empower and involve local governments, corporations, schools, homes, and individuals in the construction, financing, and maintenance of the water infrastructure. Water For People has established a year-round presence in 30 districts of nine developing countries, including Guatemala, Honduras, Nicaragua, Bolivia, Peru, India, Rwanda, Uganda and Malawi. In totality, Water For People reaches 4 million people.
The Philadelphia Water Department is the public water utility for the City of Philadelphia. PWD provides integrated potable water, wastewater, and stormwater services for Philadelphia and some communities in Bucks, Delaware and Montgomery counties. PWD is a municipal agency of the City of Philadelphia, and is seated in rented space at the Jefferson Tower in the Market East area of Center City, Philadelphia.
George Warren Fuller was an American sanitary engineer who was also trained in bacteriology and chemistry. His career extended from 1890 to 1934 and he was responsible for important innovations in water and wastewater treatment. He designed and built the first modern water filtration plant, and he designed and built the first chlorination system that disinfected a U.S. drinking water supply. In addition, he performed groundbreaking engineering work on sewage treatment facilities in the U.S. He was President of both the American Water Works Association and the American Public Health Association, and he was recognized internationally as an expert civil and sanitary engineer.
John Laing Leal was an American physician and water treatment expert who, in 1908, was responsible for conceiving and implementing the first disinfection of a U.S. drinking water supply using chlorine. He was one of the principal expert witnesses at two trials which examined the quality of the water supply in Jersey City, New Jersey, and which evaluated the safety and utility of chlorine for production of "pure and wholesome" drinking water. The second trial verdict approved the use of chlorine to disinfect drinking water which led to an explosion of its use in water supplies across the U.S.
Allen Hazen was an American civil engineer and an expert in hydraulics, flood control, water purification and sewage treatment. His career extended from 1888 to 1930, and he is, perhaps, best known for his contributions to hydraulics with the Hazen-Williams equation. Hazen published some of the seminal works on sedimentation and filtration. He was President of the New England Water Works Association and Vice President of the American Society of Civil Engineers.
George Chandler Whipple was an American civil engineer and an expert in the field of sanitary microbiology. His career extended from 1889 to 1924 and he is best known as a co-founder of the Harvard School of Public Health. Whipple published some of the most important books in the early history of public health and applied microbiology.
John Robert Baylis was an American chemist and sanitary engineer. His career extended from about 1905 to 1963 and he is best known for his work in applied research to improve drinking water purification.
Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill bacteria, viruses and other microbes in water. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery, and typhoid.
The Woodland Davis Clean Water Agency (WDCWA) is a joint project between the cities of Woodland and Davis in Yolo County, California; also in partnership with Reclamation District 2035. This agency will oversee the construction and management of the facility that will pump water from the Sacramento River to the two cities. This new facility is to provide reliable water supply, improve the water quality for drinking purposes, and improve the treated wastewater discharge from the two cities. This new facility is expected to be supplying the cities with clean surface water in June 2016.
The Kansas City Board of Public Utilities (BPU) is a publicly owned, not-for-profit public utility servicing Wyandotte County that is headquartered in Kansas City, Kansas. Overall, BPU provides service to 127.5 square miles of Wyandotte County. Electric services are provided within the Kansas City, Kansas (KCK) area, and water is supplied to KCK, as well as portions of suburban Wyandotte, Leavenworth, and Johnson counties.
A Jewell water filter was a system of sand filters for filtering and treating water for drinking purposes that made use of gravity to allow water to percolate through a column of sand inside cylindrical cisterns that was widely used in the early twentieth century. They are named after Omar Hestrian Jewell established Jewell Pure Water Company in Chicago in 1890 and managed later by two of his sons. Jewell water filters were used in many city water supply systems across the world and modified versions continue to be in use.
Eighth Avenue South Reservoir is a man-made masonry reservoir in Nashville, Tennessee. The reservoir was built on Kirkpatrick's Hill which was the former site of Fort Casino: a Union Army fort in the American Civil War. Completed in 1889, it ruptured in 1912 causing much property damage, and was repaired in 1914. In 1978, it was listed on the National Register of Historic Places listings in Davidson County, Tennessee (NRHP). The reservoir is the largest and oldest working reservoir supplying water to the city of Nashville, and remains in use as of 2022.
