Tap water

Tap water (running water, city water, town water, municipal water, etc.) is water supplied to a tap (valve). Its uses include drinking, washing, cooking, and the flushing of toilets. Indoor tap water is distributed through "indoor plumbing", which has existed since antiquity but was available to very few people until the second half of the 19th century when it began to spread in popularity in what are now developed countries. Tap water became common in many regions during the 20th century, and is now lacking mainly among people in poverty, especially in developing countries.

Tap water is often culturally assumed to be drinking water, especially in developed countries. Usually it is potable, although water quality problems are not rare. Household water purification methods such as water filters, boiling, or distillation can be used when tap water's potability is doubted. The application of technologies (such as water treatment plants) involved in providing clean water to homes, businesses, and public buildings is a major subfield of sanitary engineering. Calling a water supply "tap water" distinguishes it from the other main types of fresh water which may be available; these include water from rainwater-collecting cisterns, water from village pumps or town pumps, water from wells, or water carried from streams, rivers, or lakes (whose potability may vary).

A simple indoor water tap


Publicly available treated water has historically been associated with major increases in life expectancy and improved public health. Water-borne diseases are vastly reduced by proper sewage and fresh water availability. Providing tap water to large urban or suburban populations requires a complex and carefully designed system of collection, storage, treatment and distribution, and is commonly the responsibility of a government agency, often the same agency responsible for the removal and treatment of clean water.

Specific chemical compounds are often taken out of tap water during the treatment process to adjust the pH or remove contaminants, and chlorine may be added to kill biological toxins. Local geological conditions affecting groundwater are determining factors for the presence of various metal ions, often rendering the water "soft" or "hard".

Tap water remains susceptible to biological or chemical contamination. In the event of contamination deemed dangerous to public health, government officials typically issue an advisory regarding water consumption. In the case of biological contamination, residents are usually advised to boil their water before consumption or to use bottled water as an alternative. In the case of chemical contamination, residents may be advised to refrain from consuming tap water entirely until the matter is resolved.

In many areas a compound of fluoride is added to tap water in an effort to improve dental health among the public. In some communities "fluoridation" remains a controversial issue. (See water fluoridation controversy.)

Potable water supply

This supply may come from several possible sources.

Domestic water systems have been evolving since people first located their homes near a running water supply, such as a stream or river. The water flow also allowed sending waste water away from the residences.

Modern indoor plumbing delivers clean, safe, potable water to each service point in the distribution system. It is important that the clean water not be contaminated by the waste water (disposal) side of the process system. Historically, this contamination of drinking water has been the largest killer of humans.[1]

Tap water can sometimes appear cloudy, often mistaken for mineral impurities in the water. It is usually caused by air bubbles coming out of solution due to change in temperature or pressure. Because cold water holds more air than warm water, small bubbles will appear in water. It has a high dissolved gas content that is heated or depressurized, which reduces how much dissolved gas the water can hold. The harmless cloudiness of the water disappears quickly as the gas is released from the water.[2]

Hot water supply

Domestic hot water is provided by means of water heater appliances, or through district heating. The hot water from these units is then piped to the various fixtures and appliances that require hot water, such as lavatories, sinks, bathtubs, showers, washing machines, and dishwashers.

Fixtures and appliances

Everything in a building that uses water falls under one of two categories; fixture or appliance. As the consumption points above perform their function, most produce waste/sewage components that will require removal by the waste/sewage side of the system. The minimum is an air gap. See cross connection control & backflow prevention for an overview of backflow prevention methods and devices currently in use, both through the use of mechanical and physical principles.

Fixtures are devices that use water without an additional source of power.

Fittings and valves

Potable water supply systems are composed of pipes, fittings and valves.


The installation of water pipes can be done using the following plastic[3] and metal[3] materials:


  • polybutylene (PB)
  • high density cross-linked polyethylene (PE-X)
  • block copolymer of polypropylene (PP-B)
  • the polypropylene copolymer (PP-H)
  • random copolymer of polypropylene (random) (PP-R)
  • Layer: cross-linked polyethylene, aluminum, high-density polyethylene (PE-X / Al / PE-HD)
  • Layer: polyethylene crosslinked, aluminum, cross-linked polyethylene (PE-X / Al / PE-X)
  • Layer copolymer of a random polypropylene, aluminum, polypropylene random copolymer (PP-R / Al / PP-R)
  • polyvinyl chloride, chlorinated (PVC-C)
  • polyvinyl chloride - not softened(only cold water) (PVC-U)


Other materials, if the pipes made from them have been let into circulation and the widespread use in the construction of the water supply systems.

Lead pipes

For many centuries, water pipes were made of lead, because of its ease of processing and durability. The use of lead pipes was a cause of health problems due to ignorance of the dangers of lead on the human body, which causes miscarriages and high death rates of newborns. Lead pipes, which were installed mostly in the late 1800s in the US, are still common today, much of which are located in the Northeast and the Midwest. Their impact is relatively small due to the fouling of pipes and stone cessation of the evolution of lead in the water; however, lead pipes are still detrimental. Most of the lead pipes that exist today are being removed and replaced with the more common material, copper or some type of plastic.

Remnants of pipes in some languages are the names of the experts involved in the execution, reparation, maintenance, and installation of water supply systems, which have been formed from the Latin word 'lead', English word 'plumber', French word, 'plombier'.

Regulation and compliance

United States

Before a water supply system is constructed or modified, the designer and contractor need to consult the local plumbing code and obtain a building permit prior to construction.[4][5] Even replacing an existing water heater may require a permit and inspection of the work. The US national standard for potable water piping guidelines is NSF/ANSI 61 certified materials. NSF/ANSI also sets standards for certifying polytanks, though the FDA approves the materials. National and local fire codes should be integrated in the design phase of the water system too to prevent "failure to comply with regulations" notices. Some areas of the United States require on-site water reserves of potable and fire water by law.


Wastewater from various appliances, fixtures, and taps is transferred to the waste and sewage removal system via the sewage drain system to treatment plants. This system consists of larger diameter piping, water traps, and ventilation to prevent toxic gases from entering the living space.

Water flow reduction

Water flow through a tap can be reduced by inexpensive small plastic flow reducers. These restrict flow between 15 and 50%, aiding water conservation and reducing the burden on both water supply and treatment facilities.

Comparison to bottled water

In modern Western society, levels of contaminants found in tap water vary for every household and plumbing system but tend to be low. Two general conceptions with popular appeal are:

  1. That tap water is widely contaminated
  2. That bottled water is assuredly pure

Both lack scientific support. In reality, both tap water and bottled water are usually safe, although in both cases exceptions can occur. The University of Cincinnati recently completed a Tap Water Quality Analysis, funded by PUR, for major US cities.[6] Its findings show generally safe water quality in most regions. While most US cities have what is considered safe tap water, contaminants ranging from bacteria to heavy metals are present in some tap water, and occasionally serious violations of tap water standards have been well-publicized, such as the severe 1993 Cryptosporidium outbreak in Milwaukee, Wisconsin, which led to several deaths and around 400,000 illnesses (see: Milwaukee Cryptosporidium outbreak). Regarding bottled water quality perceptions and reality, in 1999, the Natural Resources Defense Council (NRDC) released controversial findings from a 4-year study on bottled water. The results of this study claimed that one-third of the waters tested contained levels of contamination—including synthetic organic chemicals, bacteria, and arsenic—in at least one sample that exceeded allowable limits under either state or bottled water industry standards or guidelines.[7] However, the bottled water industry was quick to dispute the claim, saying bottled water is one of the most highly regulated food products under the FDA regulatory authority and that the FDA system worked extremely well when coupled with the International Bottled Water Association's Model Code and unannounced inspections.[8]

Using tap water (whether straight from the tap or filtered first) is generally considered to be better for one's environmental impact than habitually drinking bottled water, because the bottling and distribution of bottled water consumes resources and produces emissions (electricity and oil to make the bottles, diesel fuel to truck the filled bottles through the supply chain, truck exhaust, powerplant emissions, bottle recycling, and so on). In comparison, the water treatment plant activities were going to happen anyway in either case, but the other costs and effects are avoided in the tap water case.

Many municipalities in the United States are making an effort to use tap water over bottled water on government properties and events. However, others voted the idea down, including voters in the state of Washington, who repealed a bottled water tax via citizen initiative.[9]

James Workman, author of the book Heart of Dryness: How the Last Bushmen Can Help Us Endure the Coming Age of Permanent Drought and co-founder of SmartMarkets says that he doesn't believe that "tap water is bad and bottled water is good". Rather he cites differences in quality regulations and standards. "Bottled water is often tap water put through another filter and not held to the same quality regulations as public utility water is."[10]

Chlorine is a disinfectant which is added to tap water in the United States.[11] Chlorine can leave organic material like trihalomethanes and haloacetic acids in the water. The level of chlorine found is small, 1L of chlorinated water gives 0.2 mg of chlorine, which has not been found to cause any health problems.[12]

See also


  1. ^ Plumbing: the Arteries of Civilization, Modern Marvels video series, The History Channel, AAE-42223, A&E Television, 1996
  2. ^ Massachusetts Water Resource Authority. http://www.mwra.com/04water/2004/whitewater.htm
  3. ^ a b "INSTALACJE WODOCIĄGOWE". Anr.gov.pl. 2003.
  4. ^ Uniform Plumbing Code, IAPMO
  5. ^ International Plumbing Code, ICC
  6. ^ "Tap Water Quality Analysis"
  7. ^ "NRDC: Summary Findings of NRDC's 1999 Bottled Water Report". nrdc.org. Retrieved 21 May 2015.
  8. ^ "Key Message Points". bottledwater.org. Retrieved 21 May 2015.
  9. ^ Washington's Gregoire plans 400 million more in budget cuts, Bloomberg Businessweek, December 16, 2010
  10. ^ van der Leun, Justine (September 2009). "A Closer Look at New Research on Water Safety". AOL Health. Retrieved September 2009. Check date values in: |accessdate= (help)
  11. ^ Saucerman, Linda (September 2007). Chlorine. The Rosen Publishing Group. ISBN 9781404219625.
  12. ^ Petraccia, L., Liberati, G., Masciullo S.G., Grassi, M. & Fraioli, A. "Water, mineral waters and health". Clinical Nutrition. 25 (3): 377–385. doi:10.1016/j.clnu.2005.10.002.CS1 maint: Multiple names: authors list (link)
  • ASTM B75-02 Specification for Seamless Copper Tube
  • ASTM B42-02e1 Standard Specification for Seamless Copper Pipe, Standard Sizes
  • ASTM B88-03 Standard Specification for Seamless Copper Water Tube
  • AWWA Research Foundation, Residential End Uses of Water, ISBN 1-58321-016-4, 1999

External links

Arakawa River (Kantō)

The Arakawa River (荒川, Arakawa) is a 173-kilometre (107 mi) long river that flows through Saitama Prefecture and Tokyo.It originates on Mount Kobushi in Saitama Prefecture, and empties into Tokyo Bay. It has a total catchment area of 2,940 km2 (1,140 sq mi).

The river is one of Tokyo's major sources of tap water, and together with the Tone River, accounts for around 80% of Tokyo's water supply.

Bear Valley, Nevada County, California

Bear Valley is a former settlement in Nevada County, California. Situated at an elevation of 4,570 ft (1,390 m) above sea level, it still appeared on maps as of 1902. Bear Valley Campground in the beautiful Northern Sierra Nevada, is a great place to go if you love nature with its few amenities restrooms and tap water, its a place worth visiting to feast your eyes on its beauty. White water paddling and fishing are an excellent activity here if camping may not suit you. Found in moist environments the beautiful Hesperochiron Californicus Benth can be found in Bear Valley.

Bottled water

Bottled water is drinking water (e.g., well water, distilled water, mineral water, or spring water) packaged in plastic or glass water bottles. Bottled water may be carbonated or not. Sizes range from small single serving bottles to large carboys for water coolers.

Bough Beech

Bough Beech is a hamlet in the county of Kent, England, and is south of the Bough Beech Reservoir. It is located approximately three miles east of Edenbridge (of which it is part) and five miles south west of Sevenoaks. It is in the civil parish of Chiddingstone. The reservoir is a nature reserve, in particular for bird watching; it is especially important for migrating osprey, though they are a rare sight now the reservoir is no longer stocked with trout.

The reservoir is owned by the SES Water Company, who supply tap water to settlements west of the reservoir; including Gatwick Airport in West Sussex and Morden in south London.

The hamlet of Bough Beech is close to the Redhill to Tonbridge Line and has a pub, 'The Wheatsheaf'.

Canarian wrinkly potatoes

Papas arrugadas ([ˈpapas aruˈɣaðas] "wrinkly potatoes") is a traditional boiled potato dish eaten in the Canary Islands. It is usually served with a chili pepper garlic sauce, called mojo rojo, or as an accompaniment to meat dishes.

The dish is made from small new potatoes which are cleaned (but not peeled), then boiled in salt water. Originally, seawater was used, but today it is more common to use tap water with a very generous amount of salt added. After cooking, the water is removed and the potatoes are briefly left in the pot on the stove to dry off, until they become shrivelled with a fine salt crust.Papas arrugadas are considered a signature dish of Canarian cuisine. The dish is sometimes served with conejo en salmorejo, a common Canarian rabbit stew.

Cold finger

A cold finger is a piece of laboratory equipment that is used to generate a localized cold surface. It is named for its resemblance to a finger and is a type of cold trap. The device usually consists of a chamber that a coolant fluid (cold tap water, or perhaps something colder) can enter and leave. Another version involves filling the device with a cold material (examples: ice, dry ice or a mixture such as dry ice/acetone or ice/water).

Typically a cold finger is used in a sublimation apparatus, or can be used as a compact version of a condenser in either reflux reaction or distillation apparatus. Many commercially available rotary evaporators can be purchased with a cold finger in place of a Dimroth condenser, for example. When used as a condenser in a rotary evaporator, cold fingers can be cooled to a lower temperature of −78 °C (dry ice), compared with water condensers that can be cooled to −40 °C (ethylene glycol/water mixture). The lower temperature achieved reduces the quantity of volatile material exhausted into the air.


Dasani () is a brand of bottled water from the Coca-Cola company, launched in 1999, after the success of Aquafina (produced by Coca-Cola-rival PepsiCo). It is one of many brands of Coca-Cola bottled water sold around the world. The product is tap water, filtered and bottled.

Drinking water

Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation. The amount of drinking water required varies. It depends on physical activity, age, health issues, and environmental conditions. Americans, on average, drink one litre of water a day and 95% drink less than three litres per day. For those who work in a hot climate, up to 16 litres a day may be required. Water is essential for life.Typically in developed countries, tap water meets drinking water quality standards, even though only a small proportion is actually consumed or used in food preparation. Other typical uses include washing, toilets, and irrigation. Greywater may also be used for toilets or irrigation. Its use for irrigation however may be associated with risks. Water may also be unacceptable due to levels of toxins or suspended solids.

Globally, by 2015, 89% of people had access to water from a source that is suitable for drinking – called improved water source. In Sub-Saharan Africa, access to potable water ranged from 40% to 80% of the population. Nearly 4.2 billion people worldwide had access to tap water, while another 2.4 billion had access to wells or public taps. The World Health Organization considers access to safe drinking-water a basic human right.

About 1 to 2 billion people lack safe drinking water, a problem that causes 30,000 deaths each week. More people die from unsafe water than from war, U.N. Secretary-General Ban Ki-Moon said in 2010.

Green nails

Green nails may be (1) due to a Pseudomonas aeruginosa infection causing a green nail syndrome or (2) the result of copper in tap water.


H2NO refers to an upselling campaign by Coca-Cola to dissuade consumers from ordering tap water drinks at restaurants, and to instead order more profitable soft drinks, non-carbonated beverages, or bottled water. The campaign's title, H2NO, reflects the program's purpose, which is to have customers say No to H2O, the chemical formula for water. The program taught waiters how to use "suggestive selling techniques" to offer a variety of alternative beverages when diners asked for water.In July 2001, a link to a story about the program's success at Olive Garden was posted to Cockeyed.com. The link was reposted around the internet, until the story was taken down by Coca-Cola on August 2, 2001, for fears it might be misinterpreted. On August 20, 2001, the story was covered by The New York Times, and subsequently by a number of news providers.

The campaign ran only in the United States.

Mycobacterium chelonae

Mycobacterium chelonae is a species of the phylum Actinobacteria (Gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus Mycobacterium. Mycobacterium chelonae is a rapidly growing mycobacterium, that is found all throughout the environment including sewage and tap water. It can occasionally cause opportunistic infections of humans.

It is grouped in Runyon group IV.Type strain: strain CM 6388 = ATCC 35752 = CCUG 47445 = CIP 104535 = DSM 43804 = JCM 6388 = NCTC 946.

The complete genome sequence of M. chelonae CCUG 47445 type strain was deposited and published in DNA Data Bank of Japan, European Nucleotide Archive and GenBank in 2016 under the accession number CP007220.

Mycobacterium tusciae

Mycobacterium tusciae is a slow-growing, scotochromogenic mycobacterium first isolated from a lymph node of an immunocompromised child and subsequently from tap water and from a respiratory specimen of a patient with chronic fibrosis.

Etymology: tusciae referring to the Italian region of Tuscany, where the organisms were first isolated.

Nasal irrigation

Nasal irrigation, (also called nasal lavage or nasal douche) is a personal hygiene practice in which the nasal cavity is washed to flush out mucus and debris from the nose and sinuses. The practice is reported to be beneficial with only minor side effects. Nasal irrigation can also refer to the use of saline nasal spray or nebulizers to moisten the mucous membranes.

Thai Tap Water Supply

Thai Tap Water Supply Public Company Limited (TTW) is tap water producer and distributor in Nakhon Pathom and Samut Sakorn areas for the Provincial Waterworks Authority (PWA), to replace tap water production from the PWA's groundwater wells and to increase tap water production volume to accommodate consumers demand so as to help alleviate land subsidence problems and saltwater penetration in accordance with the governmental policy. Pathum Thani Water Co., Ltd. (PTW), the company's subsidiary, is engaged in the same business in Pathum Thani Province.


Thaiba is a village and former Village Development Committee that is now part of Godawari Municipality in Province No. 3 of central Nepal. At the time of the 1991 Nepal census it had a population of 4500 living in 805 individual households among which most of the population is inhabited by newars, the dominant population group of kathmandu valley. Here is a great problem of safe drinking water as it does not have clean and fresh water resources. People depend on a tap water provided by the government.

Voss (water)

Voss is a Norwegian-based brand of bottled water from the village of Vatnestrøm in Iveland municipality, Aust-Agder county. Contrary to popular belief, the water is not bottled in the municipality of Voss, which is more than 400 kilometres (250 mi) away from the actual bottling site. It is available in both still and sparkling forms.

In 2016, majority control of Voss was acquired by Reignwood Group, a Thai-Chinese company. The current Chairman of VOSS is John Shulman and the current Vice-Chairman of VOSS is Please Ruayrungruang.Voss is bottled by Voss of Norway AS, an American Limited Company headquartered in New York City. The water is marketed in over 50 countries, with a particular focus on the United States.In 2007, Women's Health magazine rated Voss first among several bottled waters by water experts. For entertainment on television, tests sponsored by Finland's national broadcasting company, Yle, three blindfolded wine experts rated Voss water lowest of the six waters tested, which included Helsinki public tap water.The company's cylindrical glass bottle was designed by Neil Kraft. Voss claims its manufacturing process is completely carbon neutral. In some countries including US, UK and Australia, VOSS still water is also packaged in plastic bottles that retain the cylindrical design.

Water chlorination

Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill certain bacteria and other microbes in tap water as chlorine is highly toxic. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery, and typhoid.

Water supply and sanitation in New Zealand

The provision of water supply and sanitation in New Zealand is generally of good quality in urban areas. It is provided by local government territorial authorities, which include city councils in urban areas and district councils in rural areas. The legal framework includes the Health Act 1956, amended in 2007, the Local Government Act 2002 and the Resource Management Act 1991.

Much of rural New Zealand relies on collection of rainwater for water supply and septic tanks for sewage disposal.

Ömerli Dam

Ömerli Dam (Turkish: Ömerli Barajı) is a rock-fill dam in Istanbul Province, Turkey.Ömerli Dam is located in Çekmeköy district of Istanbul Province. The rock-fill dam was built by the Turkish State Hydraulic Works on the Riva Creek to provide tap water for the city. Construction started in 1968, and the dam went in service in 1973.The volume of the earth mass used in the dam is 2,200 dam3 (78,000,000 cu ft). The dam has a thalweg height of 52 m (171 ft). It forms the reservoir Lake Ömerli (Turkish: Ömerli Gölü), which has a surface of 23 km2 (8.9 sq mi) and water capacity of 386 nm3 (1.36×10−23 cu ft).In 1999, a sanitation project was launched to protect the reservoir from waste water pollution. In the time span of the last twenty years after the construction of the dam, the surrounding area saw a rapid urbanization that brought the risk of pollution of the reservoir. The project foresaw the collection of waste water by collectors and treatment in sewage plants before emptying into the sea.

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