Tap water

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Indoor water tap on a ceramic hand wash basin Wasserhahn.jpg
Indoor water tap on a ceramic hand wash basin
Countries where tap water is safe to drink for locals and tourists Safe drink tap water map.png
Countries where tap water is safe to drink for locals and tourists

Tap water (also known as running water, piped water or municipal water) is water supplied through a tap, a water dispenser valve. In many countries, tap water usually has the quality of drinking water. Tap water is commonly used for drinking, cooking, washing, and toilet flushing. Indoor tap water is distributed through indoor plumbing, which has been around 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.

Contents

Governmental agencies commonly regulate tap water quality. 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).

Terminology

A synonym for tap water is piped water, a term used by the Joint Monitoring Programme (JMP) for Water Supply and Sanitation by WHO and UNICEF to describe the situation for access to drinking water in developing countries. [2] Piped water is not necessarily of drinking water quality but does count as an "improved water source" in the logic of Sustainable Development Goal 6. Other improved water sources include boreholes, protected dug wells or springs, rainwater, and bottled or water delivered by tanker. [2] : 12 

Fixtures and appliances

An outdoor drinking water tap at Desa Dasan Geria Village, West Lombok Clean water for a village in West Lombok (10686572086).jpg
An outdoor drinking water tap at Desa Dasan Geria Village, West Lombok

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.[ citation needed ]

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.

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.

Materials

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

Plastic

  • 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)

Metals

  • carbon steel, ordinary galvanized
  • corrosion resistant steel
  • Deoxidized High Phosphorus copper (Cu-DHP)
  • lead (no longer used for new installations due to its toxicity)

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. [4] 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.

Distribution systems and contamination

Modern plumbing delivers clean, safe, and potable water to each service point in water distribution system, including taps. [5] It is important that the clean water not be contaminated by the wastewater (disposal) side of the process system. Historically, this contamination of drinking water has been one of the largest killers of humans. [6]

Most of the mandates for enforcing drinking water quality standards are not for the distribution system, but for the treatment plant. Even though the water distribution system is supposed to deliver the treated water to the consumers' taps without water quality degradation, complicated physical, chemical, and biological factors within the system can cause contamination of tap water. [5]

Tap water can sometimes appear cloudy and is 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. [7]

Water supply

This section is an excerpt from Water supply.[ edit ]
A girl collects clean water from a communal water supply in Kawempe, Uganda. Africa Watsan 7 (10665637964).jpg
A girl collects clean water from a communal water supply in Kawempe, Uganda.

Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. These systems are what supply drinking water to populations around the globe. [8] Aspects of service quality include continuity of supply, water quality and water pressure. The institutional responsibility for water supply is arranged differently in different countries and regions (urban versus rural). It usually includes issues surrounding policy and regulation, service provision and standardization.

The cost of supplying water consists, to a very large extent, of fixed costs (capital costs and personnel costs) and only to a small extent of variable costs that depend on the amount of water consumed (mainly energy and chemicals). Almost all service providers in the world charge tariffs to recover part of their costs.

Comparison to bottled water

This section is an excerpt from Bottled water § Bottled water versus tap water.[ edit ]

Bottled water may have reduced amounts of copper, lead, and other metal contaminants since it does not run through the plumbing pipes where tap water is exposed to metal corrosion; however, this varies by the household and plumbing system. [9]

In much of the developed world, chlorine often is added as a disinfectant to tap water. If the water contains organic matter, this may produce other byproducts in the water such as trihalomethanes and haloacetic acids, which has shown to increase the risk of cancer. [10] The level of residual chlorine found at around 0.0002 g per litre, which is too small to cause any health problems directly. [9] The chlorine concentration recommended by World Health Organization is between 0.0002 and 0.0005 g/L. [11]

The documentary Tapped argues against the bottled water industry, asserting that tap water is healthier, more environmentally sustainable, and more ecologically sound than bottled water. The film focuses on the bottled water industry in the United States. The film has received largely positive reviews, and has spawned college campus groups such as Beyond the Bottle. Yet, as many people remain generally unaware of the negative health and environmental impacts associated with bottled water, recent research in environmental psychology has started to investigate how to reduce the public's consumption of bottled water. [12] [13] [14]

United States

Contaminant levels found in tap water vary between households and plumbing systems. While the majority of US households have access to high-quality tap water, demand for bottled water increases. [15] In 2002, the Gallup Public Opinion Poll revealed that the possible health risk associated with tap water consumption is one of the main reasons that cause American consumers to prefer bottled water over tap water. [16]

The trust level towards tap water depends on various criteria, including the existing governmental regulations towards the water quality and their appliance. In 1993, the cryptosporidium outbreak in Milwaukee, Wisconsin, led to a massive hospitalization of more than 400,000 residents and was considered the largest in US history. [17] Severe violations of tap water standards influence the decrease in public trust. [18]

The difference in water quality between bottled and tap water is debatable. In 1999, the Natural Resources Defense Council (NRDC) released controversial findings from a 4-year study on bottled water. The study claimed that one-third of the tested waters were contaminated with synthetic organic chemicals, bacteria, and arsenic. At least one sample exceeded state guidelines for contamination levels in bottled water. [19]

In the United States, some municipalities make an effort to use tap water over bottled water on governmental properties and events. Voters in Washington State repealed a bottled water tax via citizen initiative. [20] [21]

See also

Related Research Articles

<span class="mw-page-title-main">Plumbing</span> Systems for conveying fluids

Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.

<span class="mw-page-title-main">Thermoplastic</span> Plastic that softens with heat and hardens on cooling

A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

<span class="mw-page-title-main">Drinking water</span> Water safe for consumption

Drinking water or potable water is water that is safe for ingestion, either when drunk directly in liquid form or consumed indirectly through food preparation. It is often supplied through taps, in which case it is also called tap water.

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.

<span class="mw-page-title-main">Bottled water</span> Water sold as a bottled product

Bottled water is drinking water packaged in plastic or glass water bottles. Bottled water may be carbonated or not, with packaging sizes ranging from small single serving bottles to large carboys for water coolers. The consumption of bottled water is influenced by factors such as convenience, taste, perceived safety, and concerns over the quality of municipal tap water. Concerns about the environmental impact of bottled water, including the production and disposal of plastic bottles, have led to calls for more sustainable practices in the industry.

<span class="mw-page-title-main">Water supply</span> Provision of water by public utilities, commercial organisations or others

Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. These systems are what supply drinking water to populations around the globe. Aspects of service quality include continuity of supply, water quality and water pressure. The institutional responsibility for water supply is arranged differently in different countries and regions. It usually includes issues surrounding policy and regulation, service provision and standardization.

<span class="mw-page-title-main">Water supply network</span> System of engineered hydrologic and hydraulic components providing water

A water supply network or water supply system is a system of engineered hydrologic and hydraulic components that provide water supply. A water supply system typically includes the following:

  1. A drainage basin
  2. A raw water collection point where the water accumulates, such as a lake, a river, or groundwater from an underground aquifer. Raw water may be transferred using uncovered ground-level aqueducts, covered tunnels, or underground water pipes to water purification facilities.
  3. Water purification facilities. Treated water is transferred using water pipes.
  4. Water storage facilities such as reservoirs, water tanks, or water towers. Smaller water systems may store the water in cisterns or pressure vessels. Tall buildings may also need to store water locally in pressure vessels in order for the water to reach the upper floors.
  5. Additional water pressurizing components such as pumping stations may need to be situated at the outlet of underground or aboveground reservoirs or cisterns.
  6. A pipe network for distribution of water to consumers and other usage points
  7. Connections to the sewers are generally found downstream of the water consumers, but the sewer system is considered to be a separate system, rather than part of the water supply system.
<span class="mw-page-title-main">High-density polyethylene</span> Class of polyethylenes

High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled, and has the number "2" as its resin identification code.

<span class="mw-page-title-main">Water bottle</span> Container for liquids

A water bottle is a container that is used to hold liquids, mainly water, for the purpose of transporting a drink while travelling or while otherwise away from a supply of potable water.

Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links. It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, insulation for high tension electrical cables, and baby play mats. It is also used for natural gas and offshore oil applications, chemical transportation, and transportation of sewage and slurries. PEX is an alternative to polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC) or copper tubing for use as residential water pipes.

<span class="mw-page-title-main">Pipe (fluid conveyance)</span> Tubular section or hollow cylinder

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; a hollow pipe is far stiffer per unit weight than the solid members.

<span class="mw-page-title-main">Lead and Copper Rule</span> US drinking water regulation

The Lead and Copper Rule (LCR) is a United States federal regulation that limits the concentration of lead and copper allowed in public drinking water at the consumer's tap, as well as limiting the permissible amount of pipe corrosion occurring due to the water itself. The U.S. Environmental Protection Agency (EPA) first issued the rule in 1991 pursuant to the Safe Drinking Water Act (SDWA). The EPA promulgated the regulations following studies that concluded that copper and lead have an adverse effect on individuals. The LCR limits the levels of these metals in water through improving water treatment centers, determining copper and lead levels for customers who use lead plumbing parts, and eliminating the water source as a source of lead and copper. If the lead and copper levels exceed the "action levels", water suppliers are required to educate their consumers on how to reduce exposure to lead. In a 2005 report EPA stated that the LCR requirements had been effective in 96 percent of systems serving at least 3,300 people.

<span class="mw-page-title-main">Rainwater tank</span>

A rainwater tank is a water tank used to collect and store rain water runoff, typically from rooftops via pipes. Rainwater tanks are devices for collecting and maintaining harvested rain. A rainwater catchment or collection system can yield 1,000 litres (260 US gal) of water from 1 cm (0.4 in) of rain on a 100 m2 (1,100 sq ft) roof.

<span class="mw-page-title-main">Piping and plumbing fitting</span> Connecting pieces in pipe systems

A fitting or adapter is used in pipe systems to connect sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of fluids such as water for potatory, irrigational, sanitary, and refrigerative purposes, gas, petroleum, liquid waste, or any other liquid or gaseous substances required in domestic or commercial environments, within a system of pipes or tubes, connected by various methods, as dictated by the material of which these are made, the material being conveyed, and the particular environmental context in which they will be used, such as soldering, mortaring, caulking, plastic welding, welding, friction fittings, threaded fittings, and compression fittings.

Polybutylene (polybutene-1, poly(1-butene), PB-1) is a polyolefin or saturated polymer with the chemical formula (CH2CH(Et))n. Not be confused with polybutene, PB-1 is mainly used in piping.

<span class="mw-page-title-main">Plastic pipework</span> Tubular section or hollow cylinder made of plastic

Plastic pipe is a tubular section, or hollow cylinder, made of plastic. It is usually, but not necessarily, of circular cross-section, used mainly to convey substances which can flow—liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipes are far stiffer per unit weight than solid members.

Drinking water quality in the United States is generally safe. In 2016, over 90 percent of the nation's community water systems were in compliance with all published U.S. Environmental Protection Agency standards. Over 286 million Americans get their tap water from a community water system. Eight percent of the community water systems—large municipal water systems—provide water to 82 percent of the US population. The Safe Drinking Water Act requires the US EPA to set standards for drinking water quality in public water systems. Enforcement of the standards is mostly carried out by state health agencies. States may set standards that are more stringent than the federal standards.

<span class="mw-page-title-main">Lead contamination in Washington, D.C., drinking water</span>

While performing research into premature pipe corrosion for the District of Columbia Water and Sewer Authority (WASA) in 2001, Marc Edwards, an expert in plumbing corrosion, discovered lead levels in the drinking water of Washington, D.C., at least 83 times higher than the accepted safe limit. He found that the decision to change from chlorine to chloramine as a treatment chemical had caused the spike in lead levels. The contamination has left thousands of children with lifelong health risks and led to a re-evaluation of the use of monochloramine in public drinking-water systems.

<span class="mw-page-title-main">Water distribution system</span> Infrastructure to carry potable water to consumers

A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements.

<span class="mw-page-title-main">Lead service line</span> Pipe used to connect water main to users

A lead service line is a pipe made of lead which is used in potable water distribution to connect a water main to a user's premises.

References

  1. ↑ The source Where Is the World's Most Dangerous Drinking Water? (commercial website qssuplies.co.uk, March 2023) uses data of the US Centers for Disease Control and Prevention (CDC) (Destinations list, wwwnc.cdc.gov) and the Environmental Performance Index (EPI) (Unsafe drinking water, epi.yale.edu, 2022). The EPI estimates rely on data of the Institute for Health Metrics and Evaluation (IHME) Global Burden of Disease (GBD) study
  2. 1 2 Progress on household drinking water, sanitation and hygiene 2000–2022: special focus on gender. New York: United Nations Children’s Fund (UNICEF) and World Health Organization (WHO), 2023
  3. 1 2 "Takagi T-KJr2-IN-NG Indoor". tanklesses.com. 2020.
  4. ↑ Troesken, Werner (2006). The great lead water pipe disaster. MIT Press. ISBN   0-262-20167-4. OCLC   70176961.
  5. 1 2 Board., National Research Council (U.S.). Committee on Public Water Supply Distribution Systems: Assessing and Reducing Risks. National Research Council (U.S.). Water Science and Technology (2006). Drinking water distribution systems : assessing and reducing risks. National Academies Press. ISBN   0-309-10306-1. OCLC   71294470.
  6. ↑ Plumbing: the Arteries of Civilization, Modern Marvels video series, The History Chfifr5tyk A&E Television, 1996
  7. ↑ "Why is my tap water cloudy?". www.mwra.com. Retrieved 2023-03-27.
  8. ↑ "Public Supply Water Use". www.usgs.gov. Retrieved 2021-10-03.
  9. 1 2 Petraccia, L.; Liberati, G.; Masciullo S.G.; Grassi M.; Fraioli, A. (2006). "Water, mineral waters and health". Clinical Nutrition. 25 (3): 377–385. doi:10.1016/j.clnu.2005.10.002. PMID   16314004.
  10. ↑ "Final Report – Health Risk of the Trihalomethanes Found in Drinking Water Carcinogenic Activity and Interactions – Research Project Database – NCER – ORD – US EPA". epa.gov. 3 September 2009. Retrieved 13 July 2015.
  11. ↑ World Health Organization, "How to measure chlorine residual in water" WHO – Technical Notes for Emergencies, Technical Note No. 11, 4 Draft revised: 7.1.05 (pdf) Archived 7 July 2011 at the Wayback Machine
  12. ↑ van der Linden, S. "Exploring Beliefs About Bottled Water and Intentions To Reduce Consumption: The Dual-Effect of Social Norm Activation and Persuasive Information". Environment and Behavior. doi:10.1177/0013916513515239. S2CID   220350200.
  13. ↑ Santos, Jessica; van der Linden, Sander (2016). "Changing Norms by Changing Behavior: The Princeton Drink Local Program" (PDF). Environmental Practice. 18 (2): 1–7. doi:10.1017/S1466046616000144. S2CID   130162044. Archived from the original (PDF) on 16 August 2016. Retrieved 16 July 2016.
  14. ↑ "Persuading the public to reduce bottled water consumption" (PDF). European Commission. 3 September 2015.
  15. ↑ Doria, Miguel F. (2006-06-01). "Bottled water versus tap water: understanding consumers' preferences". Journal of Water and Health. 4 (2): 271–276. doi: 10.2166/wh.2006.0023 . ISSN   1477-8920. PMID   16813019.
  16. ↑ Saylor, Amber; Prokopy, Linda Stalker; Amberg, Shannon (September 2011). "What's Wrong with the Tap? Examining Perceptions of Tap Water and Bottled Water at Purdue University". Environmental Management. 48 (3): 588–601. Bibcode:2011EnMan..48..588S. doi:10.1007/s00267-011-9692-6. ISSN   0364-152X. PMID   21643837. S2CID   22067616.
  17. ↑ Mac Kenzie, William R.; Hoxie, Neil J.; Proctor, Mary E.; Gradus, M. Stephen; Blair, Kathleen A.; Peterson, Dan E.; Kazmierczak, James J.; Addiss, David G.; Fox, Kim R.; Rose, Joan B.; Davis, Jeffrey P. (1994-07-21). "A Massive Outbreak in Milwaukee of Cryptosporidium Infection Transmitted through the Public Water Supply". New England Journal of Medicine. 331 (3): 161–167. doi: 10.1056/NEJM199407213310304 . ISSN   0028-4793. PMID   7818640.
  18. ↑ Pierce, Gregory; Gonzalez, Silvia (2017-02-01). "Mistrust at the tap? Factors contributing to public drinking water (mis)perception across US households". Water Policy. 19 (1): 1–12. doi: 10.2166/wp.2016.143 . ISSN   1366-7017.
  19. ↑ "The Truth About Tap". NRDC. January 5, 2016. Retrieved 2021-04-24.
  20. ↑ McNamara, Neal (December 2, 2010). "Washington state says goodbye to bottle and candy taxes". Federal Way Mirror. Retrieved 2 April 2022.
  21. ↑ "Initiative Measure 1107 Concerns reversing certain 2010 amendments to state tax laws". Washington Secretary of State · Elections Division. Retrieved 2 April 2022.
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