Well

Excavation or structure to provide access to groundwater

The difference betwixt a well and a cistern is in the source of the water.

A well is an digging or construction created in the ground past excavation, driving, or drilling to access liquid resources, usually water. The oldest and most mutual kind of well is a h2o well, to access groundwater in hugger-mugger aquifers. The well water is drawn up by a pump, or using containers, such every bit buckets, that are raised mechanically or by hand. H2o can also exist injected back into the aquifer through the well. Wells were first constructed at least viii thousand years ago and historically vary in structure from a elementary scoop in the 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 dorsum at least as far equally the Fe Age.

Wells take traditionally been sunk by hand digging, equally is still the case in rural areas of the developing world. These wells are inexpensive and low-tech equally they employ mostly manual labour, and the construction can be lined with brick or stone as the excavation gain. A more mod method called caissoning uses pre-cast reinforced physical well rings that are lowered into the hole. Driven wells can be created in unconsolidated fabric with a well hole structure, which consists of a hardened drive point and a screen of perforated piping, after which a pump is installed to collect the h2o. Deeper wells can exist excavated by mitt drilling methods or machine drilling, using a scrap in a borehole. Drilled wells are usually cased with a manufactory-made pipage composed of steel or plastic. Drilled wells can access h2o at much greater depths than dug wells.

Two broad classes of well are shallow or unconfined wells completed inside 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 tin can exist selected past a hydrogeologist, or groundwater surveyor. Water may be pumped or mitt fatigued. Impurities from the surface tin easily accomplish shallow sources and contamination of the supply by pathogens or chemical contaminants needs to be avoided. Well h2o typically contains more minerals in solution than surface h2o and may require treatment before existence potable. Soil salination can occur as the h2o table falls and the surrounding soil begins to dry out. Another environmental problem is the potential for marsh gas to seep into the water.

History [edit]

Camel drawing h2o 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 attain 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 get-go stone lined^[two] well of 5.five metres (18 ft) depth is documented from a drowned final PPN (c. 7000 BC) site at 'Atlit-Yam off the coast near modernistic Haifa in Israel.

Forest-lined wells are known from the early Neolithic Linear Pottery culture, for example in Ostrov, Czech Democracy, dated 5265 BC,^[iii] Kückhoven (an outlying centre of Erkelenz), dated 5090 BC, and Eythra in Schletz (an outlying centre of Asparn an der Zaya) in Austria, dated 5200 BC.^[4]

Some of the primeval evidence of h2o wells is located in People's republic of china. The neolithic Chinese discovered and made extensive apply of deep drilled groundwater for drinking.^{[ commendation needed ]} The Chinese text The Volume 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.^[5] A well excavated at the Hemedu excavation site was believed to take been built during the neolithic era.^{[half dozen]} The well was cased by four rows of logs with a foursquare frame fastened to them at the top of the well. threescore additional tile wells southwest of Beijing are also believed to have been built around 600 BC for drinking and irrigation.^[vi] ^[seven]

A Chinese ceramic model of a well with a water pulley system, excavated from a tomb of the Han Dynasty (202 BC – 220 Advertisement) menstruum

In Egypt, shadoofs and sakias are used.^[8] ^[9] 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 globe's oldest known wells, located in Cyprus, appointment to 7000–8,500 BC.^[10] Ii wells from the Neolithic flow, around 6500 BC, have been discovered in Israel. One is in Atlit, on the northern declension of State of israel, and the other is the Jezreel Valley.^[11]

Wells for other purposes came along much after, historically. The first recorded table salt well was dug in the Sichuan province of China around two,250 years ago. This was the showtime fourth dimension that ancient h2o well technology was applied successfully for the exploitation of salt, and marked the beginning of Sichuan'south table salt drilling industry.^[5] The primeval known oil wells were too drilled in China, in 347 CE. These wells had depths of up to about 240 metres (790 ft) and were drilled using bits fastened to bamboo poles.^[12] The oil was burned to evaporate brine and produce table salt. By the 10th century, all-encompassing bamboo pipelines continued oil wells with salt springs. The ancient records of China and Japan are said to contain many allusions to the utilise of natural gas for lighting and heating. Petroleum was known as Burning water in Nihon in the 7th century.^[thirteen]

Types [edit]

Leather saucepan used for the water well

Dug wells [edit]

View into a manus-dug well cased with concrete rings. Ouelessebougou, Mali.

A dug well in a village in Kerala, Bharat

Until contempo centuries, all artificial wells were pumpless paw-dug wells of varying degrees of sophistication, and they remain a very of import 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 iv:half dozen) in the bible and the "Ding Dong Bell" nursery rhyme most a true cat in a well.

Hand-dug wells are excavations with diameters large enough to accommodate 1 or more than people with shovels digging down to below the h2o table. The excavation is braced horizontally to avoid landslide or erosion endangering the people earthworks. They tin can be lined with stone or brick; extending this lining upwards above the footing 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 physical or plain physical pre-cast well rings that are lowered into the hole. A well-digging team digs under a cutting ring and the well cavalcade 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 admission groundwater in rural locations of developing countries. They may be congenital with a loftier caste of community participation, or by local entrepreneurs who specialize in hand-dug wells. They take been successfully excavated to 60 metres (200 ft). They accept low operational and maintenance costs, in function because h2o tin be extracted by hand, without a pump. The water often comes from an aquifer or groundwater, and tin be easily deepened, which may be necessary if the basis water level drops, by telescoping the lining further downwards 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. Information technology can be impractical to hand dig wells in areas where hard rock is present, and they tin can exist time-consuming to dig and line even in favourable areas. Considering they exploit shallow aquifers, the well may be susceptible to yield fluctuations and possible contagion from surface water, including sewage. Hand dug well construction by and large requires the apply of a well trained construction team, and the capital investment for equipment such as concrete ring moulds, heavy lifting equipment, well shaft formwork, motorized de-watering pumps, and fuel can be large for people in developing countries. Construction of paw dug wells can be dangerous due to collapse of the well diameter, falling objects and asphyxiation, including from dewatering pump frazzle fumes.

The Woodingdean Water Well, manus-dug between 1858 and 1862, is the deepest mitt-dug well at 392 metres (1,285 ft).^[14] The Big Well in Greensburg, Kansas is billed equally the world's largest hand-dug well, at 109 anxiety (33 thousand) deep and 32 feet (9.8 m) in diameter. However, the Well of Joseph in the Cairo Citadel at 280 feet (85 m) deep and the Pozzo di S. Patrizio (St. Patrick'south Well) built in 1527 in Orvieto, Italy, at 61 metres (200 ft) deep by thirteen metres (43 ft) wide^[xv] are both larger by book.

Driven wells [edit]

Driven wells may be very merely created in unconsolidated material with a well pigsty structure, which consists of a hardened bulldoze point and a screen (perforated piping). The point is simply hammered into the ground, usually with a tripod and driver, with pipage sections added every bit needed. A driver is a weighted piping that slides over the pipe existence driven and is repeatedly dropped on it. When groundwater is encountered, the well is washed of sediment and a pump installed.^[16]

Drilled wells [edit]

Drilled wells are typically created using either top-head rotary style, table rotary, or cable tool drilling machines, all of which utilise drilling stems that are turned to create a cut action in the germination, hence the term drilling.

Drilled wells can be excavated by uncomplicated hand drilling methods (augering, sludging, jetting, driving, hand percussion) or motorcar drilling (rotary, percussion, downward the pigsty hammer). Deeprock rotary drilling method is about common. Rotary tin can be used in 90% of formation types.

Drilled wells tin get water from a much deeper level than dug wells can—often downwardly to several hundred metres.^[17]

Drilled wells with electric pumps are used throughout the world, typically in rural or sparsely populated areas, though many urban areas are supplied partly by municipal wells. Virtually shallow well drilling machines are mounted on big trucks, trailers, or tracked vehicle carriages. Water wells typically range from 3 to 18 metres (x–60 ft) deep, but in some areas can become deeper than 900 metres (3,000 ft).^{[ commendation needed ]}

Rotary drilling machines use a segmented steel drilling string, typically fabricated up of 6 m (20 ft) sections of galvanized steel tubing that are threaded together, with a bit or other drilling device at the lesser stop. Some rotary drilling machines are designed to install (by driving or drilling) a steel casing into the well in conjunction with the drilling of the bodily bore hole. Air and/or water is used as a circulation fluid to displace cuttings and cool bits during the drilling. Another class of rotary-style drilling, termed mud rotary, makes apply of a specially made mud, or drilling fluid, which is constantly being altered during the drill so that it can consistently create enough hydraulic pressure to hold the side walls of the bore hole open, regardless of the presence of a casing in the well. Typically, boreholes drilled into solid rock are non cased until later on the drilling process is completed, regardless of the mechanism used.

The oldest form of drilling machinery is the cable tool, notwithstanding used today. Specifically designed to heighten and lower a bit into the bore hole, the spudding of the drill causes the bit to be raised and dropped onto the bottom of the pigsty, and the design of the cable causes the bit to twist at approximately one⁄4 revolution per driblet, thereby creating a drilling action. Unlike rotary drilling, cable tool drilling requires the drilling action to be stopped so that the diameter pigsty tin can be bailed or emptied of drilled cuttings.

Drilled wells are normally cased with a mill-made piping, typically steel (in air rotary or cablevision tool drilling) or plastic/PVC (in mud rotary wells, also present in wells drilled into solid rock). The casing is constructed by welding, either chemically or thermally, segments of casing together. If the casing is installed during the drilling, nigh drills will bulldoze the casing into the ground as the diameter hole advances, while some newer machines volition actually allow for the casing to be rotated and drilled into the formation in a similar style as the chip advancing simply below. PVC or plastic is typically welded and and so lowered into the drilled well, vertically stacked with their ends nested and either glued or splined together. The sections of casing are usually 6 metres (20 ft) or more in length, and 6 to 12 in (xv to thirty cm) in diameter, depending on the intended utilise of the well and local groundwater conditions.

Surface contamination of wells in the United States is typically controlled by the utilize of a surface seal. A large hole is drilled to a predetermined depth or to a confining formation (clay or bedrock, for instance), and and so a smaller hole for the well is completed from that point forward. The well is typically cased from the surface down into the smaller pigsty with a casing that is the same bore as that hole. The annular space between the large diameter pigsty and the smaller casing is filled with bentonite clay, concrete, or other sealant material. This creates an impermeable seal from the surface to the next confining layer that keeps contaminants from traveling downwards the outer sidewalls of the casing or borehole and into the aquifer. In improver, wells are typically capped with either an engineered well cap or seal that vents air through a screen into the well, only keeps insects, small animals, and unauthorized persons from accessing the well.

At the bottom of wells, based on formation, a screening device, filter pack, slotted casing, or open bore hole is left to allow the flow of water into the well. Constructed screens are typically used in unconsolidated formations (sands, gravels, etc.), allowing h2o and a percent of the formation to pass through the screen. Allowing some material to laissez passer through creates a large area filter out of the rest of the germination, equally the corporeality of material present to pass into the well slowly decreases and is removed from the well. Rock wells are typically cased with a PVC liner/casing and screen or slotted casing at the lesser, this is mostly nowadays just to proceed rocks from inbound the pump assembly. Some wells employ a filter pack method, where an undersized screen or slotted casing is placed inside the well and a filter medium is packed effectually the screen, between the screen and the borehole or casing. This allows the water to be filtered of unwanted materials before inbound the well and pumping zone.

An automated water well arrangement powered by a jet-pump
An automated h2o well organization powered past a submersible pump
A h2o well system with a cistern
A water well system with a pressurized cistern
A section of a stainless steel screen well

Classification [edit]

There are two wide classes of drilled-well types, based on the type of aquifer the well is in:

Shallow or unconfined wells are completed in the uppermost saturated aquifer at that location (the upper unconfined aquifer).^{[ citation needed ]}
Deep or confined wells are sunk through an impermeable stratum into an aquifer that is sandwiched between ii impermeable strata (aquitards or aquicludes). The bulk of deep aquifers are classified as artesian because the hydraulic head in a confined well is higher than the level of the tiptop of the aquifer. If the hydraulic head in a bars well is higher than the country surface it is a "flowing" artesian well (named afterward Artois in France).^{[ citation needed ]}

A special type of water well may be constructed adjacent to freshwater lakes or streams. Commonly chosen a collector well but sometimes referred to by the merchandise name Ranney well or Ranney collector, this blazon of well involves sinking a caisson vertically below the top of the aquifer and then advancing lateral collectors out of the caisson and beneath the surface water trunk. Pumping from within the caisson induces infiltration of water from the surface water body into the aquifer, where it is collected by the collector well laterals and conveyed into the caisson where information technology can be pumped to the ground surface.^{[ citation needed ]}

Two additional wide classes of well types may exist distinguished, based on the use of the well:

production or pumping wells, are big diameter (greater than 15 cm in diameter) cased (metal, plastic, or concrete) water wells, constructed for extracting water from the aquifer by a pump (if the well is non artesian).^{[ citation needed ]}
monitoring wells or piezometers, are often smaller diameter wells used to monitor the hydraulic head or sample the groundwater for chemical constituents. Piezometers are monitoring wells completed over a very short department of aquifer. Monitoring wells tin can also be completed at multiple levels, allowing discrete samples or measurements to be fabricated at unlike vertical elevations at the same map location.^{[ citation needed ]}

A well synthetic for pumping groundwater can be used passively every bit a monitoring well and a modest diameter well can be pumped, but this distinction by utilise is common.^{[ citation needed ]}

Siting [edit]

Before excavation, information about the geology, water table depth, seasonal fluctuations, recharge area and rate must be plant. This piece of work is typically done by a hydrogeologist, or a groundwater surveyor using a variety of tools including electro-seismic surveying,^[18] any available information from nearby wells, geologic maps, and sometimes geophysical imaging.

Contamination [edit]

Paw pump to pump h2o from a well in a village about Chennai in Bharat, where the well h2o might exist polluted by nearby pit latrines

Shallow pumping wells can often supply drinking water at a very depression cost. However, impurities from the surface easily reach shallow sources, which leads to a greater risk of contagion for these wells compared to deeper wells. Contaminated wells can pb to the spread of diverse waterborne diseases. Dug and driven wells are relatively like shooting fish in a barrel to contaminate; for instance, well-nigh dug wells are unreliable in the majority of the U.s.a..^[19]

Pathogens [edit]

Almost of the bacteria, viruses, parasites, and fungi that contaminate well h2o comes from fecal cloth from humans and other animals, for case from on-site sanitation systems (such as pit latrines and septic tanks). Common bacterial contaminants include Due east. coli, Salmonella, Shigella, and Campylobacter jejuni. Common viral contaminants include norovirus, sapovirus, rotavirus, enteroviruses, and hepatitis A and E. Parasites include Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, and microsporidia.^[nineteen]

Chemic contamination [edit]

Chemical contagion is a common trouble with groundwater.^[xx] Nitrates from sewage, sewage sludge or fertilizer are a item problem for babies and young children. Pollutant chemicals include pesticides and volatile organic compounds from gasoline, dry-cleaning, the fuel additive methyl tert-butyl ether (MTBE), and perchlorate from rocket fuel, airbag inflators, and other artificial and natural sources.^{[ citation needed ]}

Several minerals are as well contaminants, including atomic number 82 leached from brass fittings or old lead pipes, chromium 6 from electroplating and other sources, naturally occurring arsenic, radon, and uranium—all of which tin crusade cancer—and naturally occurring fluoride, which is desirable in low quantities to prevent tooth decay, simply tin can crusade dental fluorosis in college concentrations.^[19]

Some chemicals are commonly present in water wells at levels that are not toxic, merely tin can cause other bug. Calcium and magnesium cause what is known as hard h2o, which tin precipitate and clog pipes or burn out water heaters. Iron and manganese tin appear as nighttime flecks that stain clothing and plumbing, and tin can promote the growth of atomic number 26 and manganese leaner that can form slimy black colonies that clog pipes.^[19]

Prevention [edit]

The quality of the well water can exist significantly increased past lining the well, sealing the well head, fitting a cocky-priming paw pump, constructing an frock, ensuring the area is kept clean and costless from stagnant h2o and animals, moving sources of contamination (pit latrines, garbage pits, on-site sewer systems) and carrying out hygiene educational activity. The well should be cleaned with 1% chlorine solution afterwards construction and periodically every six months.^{[ citation needed ]}

Well holes should exist covered to prevent loose debris, animals, animal excrement, and wind-diddled foreign matter from falling into the hole and decomposing. The comprehend should be able to be in place at all times, including when drawing water from the well. A suspended roof over an open hole helps to some degree, but ideally the comprehend should be tight plumbing fixtures and fully enclosing, with but a screened air vent.^{[ citation needed ]}

Minimum distances and soil percolation requirements between sewage disposal sites and h2o wells need to be observed. Rules regarding the design and installation of individual and municipal septic systems take all these factors into account so that nearby drinking h2o sources are protected.

Education of the full general population in social club also plays an important role in protecting drinking h2o.^{[ citation needed ]}

Mitigation [edit]

Cleanup of contaminated groundwater tends to be very costly. Effective remediation of groundwater is generally very difficult. Contamination of groundwater from surface and subsurface sources can usually exist dramatically reduced by correctly centering the casing during construction and filling the casing annulus with an appropriate sealing material. The sealing material (grout) should be placed from immediately higher up the production zone back to surface, because, in the absence of a correctly constructed casing seal, contaminated fluid can travel into the well through the casing annulus. Centering devices are of import (ordinarily one per length of casing or at maximum intervals of ix m) to ensure that the grouted annular space is of even thickness.^{[ citation needed ]}

Upon the structure of a new test well, information technology is considered best practice to invest in a complete battery of chemical and biological tests on the well water in question. Indicate-of-utilise treatment is bachelor for private properties and treatment plants are often synthetic for municipal water supplies that suffer from contamination. Most of these treatment methods involve the filtration of the contaminants of concern, and additional protection may be garnered by installing well-casing screens but at depths where contamination is non present.^{[ citation needed ]}

Wellwater for personal use is often filtered with opposite osmosis water processors; this process can remove very small particles. A unproblematic, constructive way of killing microorganisms is to bring the h2o to a total boil for one to three minutes, depending on location. A household well contaminated by microorganisms can initially be treated by daze chlorination using bleach, generating concentrations hundreds of times greater than found in community water systems; however, this volition not ready any structural problems that led to the contagion and by and large requires some expertise and testing for constructive awarding.^[xix]

After the filtration procedure, it is common to implement an ultraviolet (UV) organization to impale pathogens in the h2o. UV light affects the DNA of the pathogen by UV-C photons breaking through the cell wall. UV disinfection has been gaining popularity in the past decades as it is a chemical-complimentary method of water treatment.^[21]

Environmental bug [edit]

A chance with the placement of water wells is soil salination which occurs when the water table of the soil begins to drop and salt begins to accumulate as the soil begins to dry.^[22] Another ecology problem that is very prevalent in water well drilling is the potential for methyl hydride to seep through.

Soil salination [edit]

The potential for soil salination is a large risk when choosing the placement of h2o wells. Soil salination is caused when the water table of the soil drops over time and table salt begins to accumulate. In plow, the increased amount of salt begins to dry out the soil out. This is a very detrimental problem because the increased level of salt in the soil can result in the degradation of soil and can be very harmful to vegetation.^{[ commendation needed ]}

Methane [edit]

Methane, an asphyxiant, is a chemical compound that is the master component of natural gas. When methyl hydride is introduced into a bars space, it displaces oxygen, reducing oxygen concentration to a level depression enough to pose a threat to humans and other aerobic organisms merely all the same high enough for a risk of spontaneous or externally caused explosion. This potential for explosion is what poses such a danger in regards to the drilling and placement of water wells.^{[ citation needed ]}

Low levels of marsh gas in drinking water are not considered toxic. When methane seeps into a water supply, it is usually referred to every bit "methane migration". This can be acquired by sometime natural gas wells near h2o well systems becoming abandoned and no longer monitored.^{[ commendation needed ]}

Lately,^{[ when? ]} all the same, the described wells/pumps are no longer very efficient and can be replaced by either handpumps or treadle pumps. Another alternative is the apply of self-dug wells, electrical deep-well pumps (for college depths). Appropriate applied science organizations as Practical Activeness are now^{[ when? ]} supplying information on how to build/gear up-up (DIY) handpumps and treadle pumps in practice.^[23] ^[24]

H2o security [edit]

A study ended that of ~39 meg groundwater wells 6-20% are at high hazard of running dry out if local groundwater levels pass up by less than 5 meters, or – as with many areas and possibly more than than half of major aquifers^[25] – continue to decline.^[26] ^[27] ^{[ further explanation needed ]}

Society and culture [edit]

Springs and wells have had cultural significance since prehistoric times, leading to the foundation of towns such as Wells and Bathroom in Somerset. Interest in wellness benefits led to the growth of spa towns including many with wells in their proper noun, examples being Llandrindod Wells and Regal Tunbridge Wells.^[28]

Eratosthenes is sometimes claimed to have used a well in his calculation of the Earth'due south circumference; nevertheless, this is just a simplification used in a shorter explanation of Cleomedes, since Eratosthenes had used a more elaborate and precise method.^[29]

Many incidents in the Bible take place around wells, such as the finding of a wife for Isaac in Genesis and Jesus's talk with the Samaritan adult female in the Gospels.^[30]

References [edit]

^ Peltenburg, Edgar (2012). "E Mediterranean h2o wells of the ninth–7th millennium BC". In: Florian Klimscha (ed.), Wasserwirtschaftliche Innovationen im archäologischen Kontext. Von den prähistorischen Anfängen bis zu den Metropolen der Antike. Rahden/Westfalia: Leidorf: 69–82.
^ Galili, Ehud; Nir, Yaacov (1993). "The submerged Pre-Pottery Neolithic water well of Atlit-Yam, northern State of israel, and its palaeoenvironmental implications". The Holocene. 3 (3): 265–270. Bibcode:1993Holoc...3..265G. doi:ten.1177/095968369300300309. S2CID 130032420.
^ "World's oldest dendrochronologically dated archaeological wood construction". Journal of Archaeological Science. 115. 2020.
^ Tegel Due west, Elburg R, Hakelberg D, Stäuble H, Büntgen U (2012). "Early Neolithic Water Wells Reveal the Earth's Oldest Wood Architecture". PLOS One. 7 (12): e51374. Bibcode:2012PLoSO...751374T. doi:10.1371/journal.pone.0051374. PMC3526582. PMID 23284685.
^ ^a ^b Kuhn, Oliver (2004-06-thirty). "Ancient Chinese Drilling". Canadian Social club of Exploration Geophysicists. 29 (6).
^ ^a ^b Chang, Mingteh (2012). Woods Hydrology: An Introduction to Water and Forests (third ed.). CRC Press (published Nov 1, 2012). p. 31. ISBN978-1439879948.
^ Koon, Wee Kek (July 25, 2015). "How the ancient Chinese looked subsequently their drinking h2o". S China Morning Post.
^ "Sakieh explication/difference vs Sakia". Britannica.com . Retrieved 2011-12-19 .
^ "Sakia explication". Britannica.com . Retrieved 2011-12-19 .
^ "Stone Age wells constitute in Cyprus". BBC News.
^ Ashkenazi, Eli (November ix, 2012). "Ancient Well Reveals Secrets of Start Jezreel Valley Farmers". Haaretz.
^ "ASTM International – Standards Worldwide". www.astm.org.
^ Joseph P. Riva Jr. and Gordon I. Atwater. "petroleum". Encyclopædia Britannica . Retrieved 2008-06-30 .
^ "Woodingdean Well". 2005. Retrieved 26 Jan 2010.
^ "St. Patrick'south Well". Umbriatravel.com. Retrieved 2011-12-19 .
^ "How I drill a Well." Pop Science, April 1952, pp. 177–181.
^ Association), NKBA (National Kitchen and Bath (2013-x-29). Kitchen & Bathroom Residential Construction and Systems. John Wiley & Sons. ISBN9781118711040.
^ Du Preez, Michael. "ELECTRO-SEISMIC SURVEYS Practical TO MODDELING OF GROUNDWATER Catamenia SYSTEMS" (PDF). Bloemfontein, South Africa. Retrieved 21 April 2011.
^ ^a ^b ^c ^d ^e Committee on Environmental Health; Committee on Infectious Diseases (2009). "Drinking h2o from individual wells and risks to children". Pediatrics. 123 (6): 1599–1605. doi:x.1542/peds.2009-0751. PMID 19482772.
^ Clan, American Water Works (2003). Water Sources. American Water Works Association. ISBN9781583212295.
^ Meulemans, C. C. East. (1987-09-01). "The Basic Principles of UV–Disinfection of H2o". Ozone: Science & Engineering. 9 (iv): 299–313. doi:x.1080/01919518708552146. ISSN 0191-9512.
^ "Soil salination by placement of water wells mentioned in India". Ngm.nationalgeographic.com. 2002-10-17. Retrieved 2011-12-19 .
^ "Practical Answers – Handpumps". Practicalaction.org. Retrieved 2011-12-nineteen .
^ "Treadle pump". Dev.practicalaction.org. Retrieved 2011-12-19 .
^ Famiglietti, James Due south.; Ferguson, Grant (23 Apr 2021). "The hidden crisis below our anxiety". Scientific discipline. 372 (6540): 344–345. Bibcode:2021Sci...372..344F. doi:10.1126/science.abh2867. PMID 33888627. S2CID 233353241. Retrieved 10 May 2021.
^ "The largest assessment of global groundwater wells finds many are at adventure of drying upward". ScienceDaily . Retrieved 10 May 2021.
^ Jasechko, Scott; Perrone, Debra (23 April 2021). "Global groundwater wells at risk of running dry". Science. 372 (6540): 418–421. Bibcode:2021Sci...372..418J. doi:10.1126/science.abc2755. ISSN 0036-8075. PMID 33888642. S2CID 233353207. Retrieved x May 2021.
^ Burr, Thomas Benge (1766). The History of Tunbridge Wells. London.
^ Russo, Lucio (2004). The Forgotten Revolution. Berlin: Springer. pp. 273–277.
^ Bromiley, Geoffrey W. (1982), International Standard Bible Encyclopedia: E-J, Wm. B. Eerdmans Publishing, p. 955, ISBN9780802837820

Bibliography [edit]

Driscoll, F. (1986). Groundwater and Wells. St. Paul: Johnson Filtration Systems. ISBN978-0-9616456-0-1.
Raymond Rowles (1995). Drilling for Water (2nd ed.). Avebury, Cranfield University. ISBN1-85628-984-2.

External links [edit]

Sustainable Groundwater Development theme of the Rural H2o Supply Network (RWSN)
Water Portal – Akvopedia
Sustainable Sanitation and H2o Management Toolbox
U.Due south. Centers for Disease Control and Prevention (CDC) Healthy Water – Water Wells Site covering well basics, guidelines for proper siting and location of wells to avoid contagion, well testing, diseases related to wells, emergency well treatment and other topics.
US Geological Survey – Basis h2o: Wells
US Geological Survey – Water Science Pictures Flowing Artesian Well
American Footing H2o Trust
Lifewater International Technical Library
Well Structure Technical Resources for NGOs

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Source: https://en.wikipedia.org/wiki/Well