Well - Wikipedia Jump to content Main menu Main menu move to sidebar hide Navigation Main page Contents Current events Random article About Wikipedia Contact us Contribute Help Learn to edit Community portal Recent changes Upload file Special pages Search Search Appearance Donate Create account Log in Personal tools Donate Create account Log in Contents move to sidebar hide (Top) 1 History 2 Types Toggle Types subsection 2.1 Dug wells 2.2 Driven wells 2.3 Drilled wells 3 Classification 4 Siting 5 Contamination Toggle Contamination subsection 5.1 Pathogens 5.2 Chemical contamination 5.3 Prevention 5.4 Mitigation 6 Environmental problems Toggle Environmental problems subsection 6.1 Soil salination 6.2 Methane 6.3 PFAS/PFOS Fire fighting foam 7 Water security 8 Society and culture 9 Model for water well recovery 10 Similar and related water structures 11 See also 12 References Toggle References subsection 12.1 Bibliography 13 External links Toggle the table of contents Well 124 languages Alemannisch Aragonés अंगिका العربية অসমীয়া Asturianu Aymar aru Azərbaycanca Basa Bali Boarisch Žemaitėška Bikol Central Беларуская (тарашкевіца) Беларуская Български भोजपुरी বাংলা Brezhoneg Bosanski Català 閩東語 / Mìng-dĕ̤ng-ngṳ̄ Tsetsêhestâhese Čeština Чӑвашла Dansk Deutsch Zazaki Ελληνικά Esperanto Español Eesti Euskara فارسی Suomi Français Nordfriisk Gaeilge Galego Avañe'ẽ ગુજરાતી Gungbe Hausa עברית हिन्दी Hrvatski Kreyòl ayisyen Magyar Հայերեն Արեւմտահայերէն Interlingua Bahasa Indonesia Iñupiatun Italiano 日本語 Jawa Қазақша ಕನ್ನಡ 한국어 کٲشُر Kurdî Коми Latina Lëtzebuergesch Limburgs Lombard Lietuvių Latviešu Minangkabau Македонски മലയാളം मराठी Bahasa Melayu မြန်မာဘာသာ Napulitano Plattdüütsch नेपाली Li Niha Nederlands Norsk nynorsk Norsk bokmål Nouormand Occitan Ирон ਪੰਜਾਬੀ Picard Deitsch Polski Piemontèis پنجابی پښتو Português Runa Simi Română Руски Русский Sicilianu Srpskohrvatski / српскохрватски Simple English Slovenčina Slovenščina ChiShona Soomaaliga Shqip Српски / srpski Sesotho Sunda Svenska Sakizaya தமிழ் తెలుగు ไทย Tagalog Tolışi Türkçe Українська اردو Oʻzbekcha / ўзбекча Vepsän kel’ Tiếng Việt Walon 吴语 閩南語 / Bân-lâm-gí 粵語 中文 Edit links Article Talk English Read Edit View history Tools Tools move to sidebar hide Actions Read Edit View history General What links here Related changes Upload file Permanent link Page information Cite this page Get shortened URL Switch to legacy parser Print/export Download as PDF Printable version In other projects Wikimedia Commons Wikidata item Appearance move to sidebar hide From Wikipedia, the free encyclopedia Excavation or structure to provide access to groundwater This article is about water wells. For other uses, see Well (disambiguation). "Village pump" redirects here. For the set of Wikipedia discussion pages, see Wikipedia:Village pump. A dug well in a village in Faryab Province, Afghanistan The difference between a well and a cistern is in the source of the water: a cistern collects rainwater whereas a well draws from groundwater. A well is an excavation or structure created on the earth by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age. Wells have traditionally been sunk by hand digging, as is still the case in rural areas of the developing world. These wells are inexpensive and low-tech as they use mostly manual labour, and the structure can be lined with brick or stone as the excavation proceeds. A more modern method called caissoning uses pre-cast reinforced concrete well rings that are lowered into the hole. Driven wells can be created in unconsolidated material with a well hole structure, which consists of a hardened drive point and a screen of perforated pipe, after which a pump is installed to collect the water. Deeper wells can be excavated by hand drilling methods or machine drilling, using a bit in a borehole. Drilled wells are usually cased with a factory-made pipe composed of steel or plastic. Drilled wells can access water at much greater depths than dug wells. Two broad classes of well are shallow or unconfined wells completed within the uppermost saturated aquifer at that location, and deep or confined wells, sunk through an impermeable stratum into an aquifer beneath. A collector well can be constructed adjacent to a freshwater lake or stream with water percolating through the intervening material. The site of a well can be selected by a hydrogeologist, or groundwater surveyor. Water may be pumped or hand drawn. Impurities from the surface can easily reach shallow sources and contamination of the supply by pathogens or chemical contaminants needs to be avoided. Well water typically contains more minerals in solution than surface water and may require treatment before being potable. Soil salination can occur as the water table falls and the surrounding soil begins to dry out. Another environmental problem is the potential for methane to seep into the water. History [edit] See also: History of water supply and sanitation Camel drawing water from a well, Djerba island, Tunisia, 1960 Very early Neolithic wells are known from the Eastern Mediterranean.[1] The oldest reliably dated well is from the pre-pottery neolithic (PPN) site of Kissonerga-Mylouthkia on Cyprus. At around 8400 BC a shaft (well 116) of circular diameter was driven through limestone to reach an aquifer at a depth of 8 metres (26 ft). Well 2070 from Kissonerga-Mylouthkia, dating to the late PPN, reaches a depth of 13 metres (43 ft). Other slightly younger wells are known from this site and from neighbouring Parekklisha-Shillourokambos. A first stone lined[2] well of 5.5 metres (18 ft) depth is documented from a drowned final PPN (c. 7000 BC) site at 'Atlit-Yam off the coast near modern Haifa in Israel. Neolithic Linear Pottery culture well, 5300 BC, Erkelenz, Germany Wood-lined wells are known from the early Neolithic Linear Pottery culture, for example in Ostrov, Czech Republic, dated 5265 BC,[3] Kückhoven (an outlying centre of Erkelenz), dated 5300 BC,[4] and Eythra in Schletz (an outlying centre of Asparn an der Zaya) in Austria, dated 5200 BC.[5] The Neolithic Chinese discovered and made extensive use of deep drilled groundwater for drinking.[citation needed] The Chinese text The Book of Changes, originally a divination text of the Western Zhou dynasty (1046 -771 BC), contains an entry describing how the ancient Chinese maintained their wells and protected their sources of water.[6] A well excavated at the Hemedu excavation site was believed to have been built during the neolithic era.[7] The well was cased by four rows of logs with a square frame attached to them at the top of the well. 60 additional tile wells southwest of Beijing are also believed to have been built around 600 BC for drinking and irrigation.[7][8] A Chinese ceramic model of a well with a water pulley system, excavated from a tomb of the Han dynasty (202 BC – 220 AD) period In Egypt, shadoofs and sakias are used.[9][10] The sakia is much more efficient, as it can bring up water from a depth of 10 metres (versus the 3 metres of the shadoof). The sakia is the Egyptian version of the noria. Some of the world's oldest known wells, located in Cyprus, date to 7000–8,500 BC.[11] Two wells from the Neolithic period, around 6500 BC, have been discovered in Israel. One is in Atlit, on the northern coast of Israel, and the other is in the Jezreel Valley.[12] Wells for other purposes came along much later, historically. The first recorded salt well was dug in the Sichuan province of China around 2,250 years ago. This was the first time that ancient water well technology was applied successfully for the exploitation of salt, and marked the beginning of Sichuan's salt drilling industry.[6] The earliest known oil wells were also drilled in China, in 347 CE. These wells had depths of up to about 240 metres (790 ft) and were drilled using bits attached to bamboo poles.[13] The oil was burned to evaporate brine and produce salt. By the 10th century, extensive bamboo pipelines connected oil wells with salt springs. The ancient records of China and Japan are said to contain many allusions to the use of natural gas for lighting and heating. Petroleum was known as Burning water in Japan in the 7th century.[14] Types [edit] Water well near Simaisma, eastern Qatar Leather bucket used for the water well Well, Historical Village, Bhaini Sahib, Ludhiana, Punjab, India Dug wells [edit] View into a hand-dug well cased with concrete rings. Ouelessebougou, Mali. A dug well in a village in Kerala, India Well with a flower bag-shaped wall and podium Until recent centuries, all artificial wells were pumpless hand-dug wells of varying degrees of sophistication, and they remain a very important source of potable water in some rural developing areas, where they are routinely dug and used today. Their indispensability has produced a number of literary references, literal and figurative, including the reference to the incident of Jesus meeting a woman at Jacob's well (John 4:6) in the Bible and the "Ding Dong Bell" nursery rhyme about a cat in a well. Hand-dug wells are excavations with diameters large enough to accommodate one or more people with shovels digging down to below the water table. The excavation is braced horizontally to avoid landslide or erosion endangering the people digging. They can be lined with stone or brick; extending this lining upwards above the ground surface to form a wall around the well serves to reduce both contamination and accidental falls into the well. A more modern method called caissoning uses reinforced concrete or plain concrete pre-cast well rings that are lowered into the hole. A well-digging team digs under a cutting ring and the well column slowly sinks into the aquifer, whilst protecting the team from collapse of the well bore. Hand-dug wells are inexpensive and low tech (compared to drilling) and they use mostly manual labour to access groundwater in rural locations of developing countries. They may be built with a high degree of community participation, or by local entrepreneurs who specialize in hand-dug wells. They have been successfully excavated to 60 metres (200 ft). They have low operational and maintenance costs, in part because water can be extracted by hand, without a pump. The water often comes from an aquifer or groundwater, and can be easily deepened, which may be necessary if the ground water level drops, by telescoping the lining further down into the aquifer. The yield of existing hand dug wells may be improved by deepening or introducing vertical tunnels or perforated pipes. Drawbacks to hand-dug wells are numerous. It can be impractical to hand dig wells in areas where hard rock is present, and they can be time-consuming to dig and line even in favourable areas. Because they exploit shallow aquifers, the well may be susceptible to yield fluctuations and possible contaminati…