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69-598: The basin has long been a source of coal, and more recently of coalbed methane. It is known for its well-preserved exposures of the Cretaceous–Paleogene boundary (K–T boundary), which has been intensively studied for evidence of meteorite impact. Although structurally a basin, the Raton Basin forms a topographic high dissected by eastward-flowing streams such as the Purgatoire River . The basin forms

138-419: A concentration of iridium hundreds of times greater than normal. They suggested that this layer was evidence of an impact event that triggered worldwide climate disruption and caused the Cretaceous–Paleogene extinction event , a mass extinction in which 75% of plant and animal species on Earth suddenly became extinct, including all non- avian dinosaurs . When it was originally proposed, one issue with

207-520: A sulfuric acid aerosol . This would have further reduced the sunlight reaching the Earth's surface and then over several days, precipitated planet-wide as acid rain , killing vegetation, plankton and organisms which build shells from calcium carbonate ( coccolithophorids and molluscs ). Before 2000, arguments that the Deccan Traps flood basalts caused the extinction were usually linked to

276-580: A ballistic trajectory into space before it fell down as an impactor. Due to the spectacular nature of this proposed mechanism, the scientific community has largely reacted with skepticism to this hypothesis. It is possible that more than one of these hypotheses may be a partial solution to the mystery, and that more than one of these events may have occurred. Both the Deccan Traps and the Chicxulub impact may have been important contributors. For example,

345-437: A few percent carbon dioxide . Coalbed methane is generally formed due to thermal maturation of kerogen and organic matter, in contrast to coal seams with regular groundwater recharge where methane is typically generated by microbial communities living in situ . Coalbed methane grew out of venting methane from coal seams. Some coal beds have long been known to be "gassy," and as a safety measure, boreholes were drilled into

414-653: A field development plan approved. With the completion of the drilling of 23 vertical production wells by GEECL, coalbed methane became commercially available in India on 14 July 2007 with CNG priced at ₹30 per kg. Initially 90% of the CBM would be distributed as CNG gas to fuel vehicles. GEECL is responsible for Southeast Asia's first CBM station and is also locating one in the West Bengal city of Asansol . Prashant Modi, President and Chief Operating Officer of GEECL, said, "With

483-528: A number of unconventional gas sources, including coalbed methane. Coalbed methane was exempted from federal price controls, and was also given a federal tax credit. In Australia, commercial extraction of coal seam gas began in 1996 in the Bowen Basin of Queensland . Gas contained in coal bed methane is mainly methane and trace quantities of ethane , nitrogen , carbon dioxide and few other gases. Intrinsic properties of coal as found in nature determine

552-419: A single impact event. The Deccan Traps could have caused extinction through several mechanisms, including the release of dust and sulfuric aerosols into the air which might have blocked sunlight and thereby reduced photosynthesis in plants. In addition, Deccan Trap volcanism might have resulted in carbon dioxide emissions which would have increased the greenhouse effect when the dust and aerosols cleared from

621-704: Is a geological signature , usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of the Cretaceous Period, the last period of the Mesozoic Era , and marks the beginning of the Paleogene Period, the first period of the Cenozoic Era. Its age is usually estimated at 66 million years, with radiometric dating yielding a more precise age of 66.043 ± 0.043 Ma. The K–Pg boundary

690-483: Is associated with the Cretaceous–Paleogene extinction event , a mass extinction which destroyed a majority of the world's Mesozoic species, including all dinosaurs except for some birds . Strong evidence exists that the extinction coincided with a large meteorite impact at the Chicxulub crater and the generally accepted scientific theory is that this impact triggered the extinction event. The word "Cretaceous"

759-410: Is because of shrinking of coal, when methane is released from its matrix, which results in opening up of fractures and increased permeability. It is also believed that due to shrinkage of coal matrix at lower reservoir pressures, there is a loss of horizontal stress in the reservoir which induces in-situ failure of coal. Such a failure has been attributed to sudden decrease in the fracture permeability of

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828-496: Is considered a non-renewable resource , although the Alberta Research Council , Alberta Geological Survey and others have argued coalbed methane is a renewable resource because the bacterial action that formed the methane is ongoing. This is subject to debate since it has also been shown that the dewatering that accompanies CBM production destroys the conditions needed for the bacteria to produce methane and

897-488: Is currently accepted as the most likely is that the mid-ocean ridges became less active and therefore sank under their own weight as sediment from uplifted orogenic belts filled in structural basins. A severe regression would have greatly reduced the continental shelf area, which is the most species-rich part of the sea, and therefore could have been enough to cause a marine mass extinction. However, research concludes that this change would have been insufficient to cause

966-528: Is derived from the Latin "creta" (chalk). It is abbreviated K (as in "K–Pg boundary") for its German translation "Kreide" (chalk). In 1980, a team of researchers led by Nobel prize-winning physicist Luis Alvarez , his son, geologist Walter Alvarez , and chemists Frank Asaro and Helen Vaughn Michel discovered that sedimentary layers found all over the world at the Cretaceous–Paleogene boundary contain

1035-456: Is estimated to have approximately 90 trillion cubic feet (2.5 trillion cubic metres) of coalbed gas. Alberta , in 2013, was the only province with commercial coalbed methane wells and is estimated to have approximately 170 trillion cubic feet (4.8 trillion cubic metres) of economically recoverable coalbed methane, with overall reserves totaling up to 500 trillion cubic feet (14 trillion cubic metres). Coalbed methane

1104-402: Is in a near-liquid state, lining the inside of pores within the coal (called the matrix). The open fractures in the coal (called the cleats) can also contain free gas or can be saturated with water. Unlike much natural gas from conventional reservoirs, coalbed methane contains very little heavier hydrocarbons such as propane or butane , and no natural-gas condensate . It often contains up to

1173-496: Is largely untested. Some methane is extracted by coal mine venting operations, and burned to generate electricity. Assessment by private industry of coalbed methane wells independent of mining began in 2008, when 55 onshore exploration licences were issued, covering 7,000 square kilometers of potential coalbed methane areas. IGas Energy became the first in the UK to commercially extract coalbed methane separate from mine venting; as of 2012,

1242-484: Is located near the town of Chicxulub , after which the crater is named. It was formed by a large asteroid or comet about 10–15 km (6.2–9.3 mi) in diameter, the Chicxulub impactor , striking the Earth. The date of the impact coincides precisely with the Cretaceous–Paleogene boundary (K–Pg boundary), slightly more than 66 million years ago. The crater is estimated to be over 150 km (93 mi) in diameter and 20 km (12 mi) in depth, well into

1311-503: Is saline or otherwise undesirable. Water from coalbed methane wells in the Powder River Basin of Wyoming, US, commonly meets federal drinking water standards, and is widely used in the area to water livestock. Its use for irrigation is limited by its relatively high sodium adsorption ratio . Depending on aquifer connectivity, water withdrawal may depress aquifers over a large area and affect groundwater flows. In Australia,

1380-466: Is similar to a standard gas well. The methane desorption process follows a curve (of gas content vs. reservoir pressure) called a Langmuir isotherm . The isotherm can be analytically described by a maximum gas content (at infinite pressure), and the pressure at which half that gas exists within the coal. These parameters (called the Langmuir volume and Langmuir pressure, respectively) are properties of

1449-575: The Dinosaur Park Formation . Another consequence was an expansion of freshwater environments, since continental runoff now had longer distances to travel before reaching oceans. While this change was favorable to freshwater vertebrates , those that prefer marine environments, such as sharks , suffered. Another discredited cause for the K–Pg extinction event is cosmic radiation from a nearby supernova explosion. An iridium anomaly at

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1518-654: The North Sea (60–65 Ma). Any other craters that might have formed in the Tethys Ocean would have been obscured by erosion and tectonic events such as the relentless northward drift of Africa and India. A very large structure in the sea floor off the west coast of India was interpreted in 2006 as a crater by three researchers. The potential Shiva crater , 450–600 km (280–370 mi) in diameter, would substantially exceed Chicxulub in size and has been estimated to be about 66 mya, an age consistent with

1587-462: The continental crust of the region of about 10–30 km (6.2–18.6 mi) depth. It makes the feature the second of the largest confirmed impact structures on Earth , and the only one whose peak ring is intact and directly accessible for scientific research. The crater was discovered by Antonio Camargo and Glen Penfield, geophysicists who had been looking for petroleum in the Yucatán during

1656-530: The iridium anomaly thought to be evidence for a large meteor impact at the end of the Cretaceous that is in turn thought to have caused the Cretaceous–Paleogene extinction event . The boundary is represented in the basin by a 1-cm thick tonstein clay layer in the Raton Formation which has been found to contain anomalously high concentrations of iridium. The boundary clay layer is accessible to

1725-490: The peak ring of the impact crater, hundreds of meters below the current sea floor, to obtain rock core samples from the impact itself. The discoveries were widely seen as confirming current theories related to both the crater impact and its effects. The shape and location of the crater indicate further causes of devastation in addition to the dust cloud. The asteroid landed right on the coast and would have caused gigantic tsunamis , for which evidence has been found all around

1794-548: The " Alvarez hypothesis " (as it came to be known) was that no documented crater matched the event. This was not a lethal blow to the theory; while the crater resulting from the impact would have been larger than 250 km (160 mi) in diameter, Earth's geological processes hide or destroy craters over time. The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico . Its center

1863-677: The CBM industry estimates extraction of 126,000 million litres (3.3 × 10 US gallons) to 280,000 million litres (7.4 × 10 US gallons) of groundwater per year; while the National Water Commission estimates extraction above 300,000 million litres (7.9 × 10 US gallons) a year. In 2012, the Aspen Skiing Company built a 3-megawatt methane-to-electricity plant in Somerset, Colorado at Oxbow Carbon's Elk Creek Mine. Coal Seam Gas resources are in

1932-545: The Igas coalbed methane wells at Doe Green, extracting gas for electrical generation, were the only commercial CBM wells in the UK. The use of CBM (in GWh) for electricity generation in the UK is as shown. United States coalbed methane production in 2017 was 1.76 trillion cubic feet (TCF), 3.6 percent of all US dry gas production that year. The 2017 production was down from the peak of 1.97 TCF in 2008. Most CBM production came from

2001-584: The K–Pg boundary. An impact at this site could have been the triggering event for the nearby Deccan Traps. However, this feature has not yet been accepted by the geologic community as an impact crater and may just be a sinkhole depression caused by salt withdrawal. Clear evidence exists that sea levels fell in the final stage of the Cretaceous by more than at any other time in the Mesozoic era. In some Maastrichtian stage rock layers from various parts of

2070-655: The Raton Basin in 1982. Thousands of wells have successfully extracted coalbed methane from the Vermejo Formation and Raton Formation coals. The productive coalbed methane area now covers the central part of the basin, and straddles the Colorado - New Mexico state line. The two major producing companies are ExxonMobil (on the Colorado side) and El Paso Corporation (on the New Mexico side). In 2007,

2139-537: The Rocky Mountain states of Colorado, Wyoming, and New Mexico. Kazakhstan could witness the development of a large coalbed methane (CBM) sector over the coming decades, according to industry professionals. Preliminary research suggests there may be as much as 900 billion m3 of gas in Kazakhstan's main coalfields – 85% of all reserves in Kazakhstan. Great Eastern Energy (GEECL) was the first company with

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2208-454: The US. Most of the gas in coal beds is in the adsorbed form. When the reservoir is put into production, water in the fracture spaces is pumped off first. This leads to a reduction of pressure enhancing desorption of gas from the matrix. Fracture permeability acts as the major channel for the gas to flow. The higher the permeability, the higher the gas production. For most coal seams found in the US,

2277-569: The United States, methane escaping from coal during mining amounts to seven percent of total methane emissions . Recovery of coal mine methane in advance of mining is seen as a major opportunity to reduce methane emissions. Companies like CNX Resources have methane abatement programs to reduce greenhouse gas emissions from active and closed mines. CBM wells are connected by a network of roads, pipelines, and compressor stations. Over time, wells may be spaced more closely in order to extract

2346-401: The amount of gas that can be recovered. Coalbed methane reservoirs are considered as a dual-porosity reservoirs. Dual porosity reservoirs are reservoirs in which porosity related to cleats (natural fractures) are responsible for flow behavior and reservoir porosity of the matrix is responsible for the storage of gas. The porosity of a coalbed methane reservoir can vary from 10%-20%; However,

2415-405: The atmosphere. In the years when the Deccan Traps theory was linked to a slower extinction, Luis Alvarez (who died in 1988) replied that paleontologists were being misled by sparse data . While his assertion was not initially well-received, later intensive field studies of fossil beds lent weight to his claim. Eventually, most paleontologists began to accept the idea that the mass extinctions at

2484-484: The basin are extensively intruded by igneous plugs, dikes and sills of Eocene to Oligocene age. Two large granitic intrusives near the axis of the basin form East Spanish Peak and West Spanish Peak . Dikes of felsic to intermediate composition radiate outward from East and West Spanish Peaks, and on the north side of the peaks have the appearance of large stone walls. Dikes of mafic and ultramafic composition trend east-northeast to west-southwest across

2553-406: The basin. Ultrapotassic lamprophyre dikes can also be found along the basin flanks, which are highly unusual in the Rocky Mountain region. The site of the Raton Basin was a coastal plain at the end of Cretaceous and beginning of Paleogene time, and has a well-preserved sequence of rocks spanning the Cretaceous–Paleogene boundary. For this reason, the Raton Basin has been studied for evidence of

2622-615: The basin. In April 2008, Pioneer Natural Resources announced that it was developing natural gas reserves in the Cretaceous Pierre Shale on leaseholds in the Raton Basin. Coals in the Raton Basin were long known to be "gassy." During development of the Morely mine in the early part of the 20th century, two gas relief wells were drilled into the coal, as a safety measure to drain off gas ahead of mining. The first wells seeking to produce coalbed methane were drilled in

2691-542: The boundary is consistent with this hypothesis. However, analysis of the boundary layer sediments failed to find Pu , a supernova byproduct which is the longest-lived plutonium isotope, with a half-life of 81 million years. An attempt to link volcanism – like the Deccan Traps – and impact events causally in the other direction compared to the proposed Shiva crater is the so-called Verneshot hypothesis (named for Jules Verne ), which proposes that volcanism might have gotten so intense as to "shoot up" material into

2760-489: The cleat porosity of the reservoir is estimated to be in the range of 0.1%-1% Adsorption capacity of coal is defined as the volume of gas adsorbed per unit mass of coal usually expressed in SCF ( standard cubic feet , the volume at standard pressure and temperature conditions) gas/ton of coal. The capacity to adsorb depends on the rank and quality of coal. The range is usually between 100 and 800 SCF/ton for most coal seams found in

2829-457: The coal seam. A high cleat density is required for profitable exploitation of CBM. Also important is the maceral composition: maceral is a microscopic, homogeneous, petrographic entity of a corresponding sedimentary rock. A high vitrinite composition is ideal for CBM extraction, while inertinite hampers the same. The rank of coal has also been linked to CBM content: a vitrinite reflectance of 0.8–1.5% has been found to imply higher productivity of

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2898-466: The coal, and vary widely. A coal in Alabama and a coal in Colorado may have radically different Langmuir parameters, despite otherwise similar coal properties. As production occurs from a coal reservoir, the changes in pressure are believed to cause changes in the porosity and permeability of the coal. This is commonly known as matrix shrinkage/swelling. As the gas is desorbed, the pressure exerted by

2967-473: The coalbed methane field of the Raton Basin produced 124 billion cubic feet of gas, making it the 17th largest source of natural gas in the United States. 37°00′N 105°00′W  /  37.0°N 105.0°W  / 37.0; -105.0 Cretaceous%E2%80%93Paleogene boundary The Cretaceous–Paleogene ( K–Pg ) boundary , formerly known as the Cretaceous–Tertiary ( K–T ) boundary ,

3036-438: The coalbed. The gas composition must be considered, because natural gas appliances are designed for gas with a heating value of about 1,000 BTU ( British thermal units ) per cubic foot, or nearly pure methane. If the gas contains more than a few percent non-flammable gases such as nitrogen or carbon dioxide , either these will have to be removed or it will have to be blended with higher-BTU gas to achieve pipeline quality . If

3105-470: The coast of the Caribbean and eastern United States—marine sand in locations which were then inland, and vegetation debris and terrestrial rocks in marine sediments dated to the time of the impact. The asteroid landed in a bed of anhydrite ( CaSO 4 ) or gypsum (CaSO 4 ·2(H 2 O)), which would have ejected large quantities of sulfur trioxide SO 3 that combined with water to produce

3174-502: The effect on global warming per unit of mass than CO 2. over 20 years, reducing to 25 times over 100 years and 7.5 times over 500 years. Analysis of life-cycle greenhouse gas emissions of energy sources indicates that generating electricity from CBM, as with conventional natural gas, has less than half the greenhouse gas effect of coal. Multiple Australian studies have indicated the long term negative environmental effects of coal seam gas extraction, both locally and globally. In

3243-488: The end of the Cretaceous were largely or at least partly due to a massive Earth impact. However, even Walter Alvarez has acknowledged that there were other major changes on Earth even before the impact, such as a drop in sea level and massive volcanic eruptions that produced the Indian Deccan Traps, and these may have contributed to the extinctions. Several other craters also appear to have been formed about

3312-533: The foothills of the Rocky Mountains, immediately east of the Sangre de Cristo Range . The sedimentary beds that form the basin are of Paleozoic , Mesozoic and Paleogene age. In the eastern part of the basin, the sedimentary section is capped by flows of basalt of Miocene age. The basin is highly asymmetrical, the beds dipping more steeply on the west side than the east. The sedimentary rocks of

3381-454: The formation geology. Coalbed methane wells often produce at lower gas rates than conventional reservoirs, typically peaking at near 300,000 cubic feet (8,500 m ) per day (about 0.100 m³/s), and can have large initial costs. The production profiles of CBM wells are typically characterized by a " negative decline " in which the gas production rate initially increases as the water is pumped off and gas begins to desorb and flow. A dry CBM well

3450-492: The formation's thickness, probably due to other factors of the area's geology. The pressure difference between the well block and the sand face should be as high as possible as is the case with any producing reservoir in general. Other affecting parameters include coal density, initial gas-phase concentration, critical gas saturation, irreducible water saturation, relative permeability to water and gas at conditions of Sw = 1.0 and Sg = 1-Sw irreducible respectively. To extract

3519-460: The gas inside the pores decreases, causing them to shrink in size and restricting gas flow through the coal. As the pores shrink, the overall matrix shrinks as well, which may eventually increase the space the gas can travel through (the cleats), increasing gas flow. The potential of a particular coalbed as a CBM source depends on the following criteria. Cleat density/intensity: cleats are joints confined within coal sheets. They impart permeability to

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3588-627: The gas, a steel-encased hole is drilled into the coal seam 100 to 1,500 metres (330 to 4,920 ft) below ground. As the pressure within the coal seam declines due to natural production or the pumping of water from the coalbed, both gas and produced water come to the surface through tubing. Then the gas is sent to a compressor station and into natural gas pipelines. The produced water is either reinjected into isolated formations, released into streams, used for irrigation, or sent to evaporation ponds. The water typically contains dissolved solids such as sodium bicarbonate and chloride but varies depending on

3657-441: The late 1970s. Penfield was initially unable to obtain evidence that the geological feature was a crater and gave up his search. Later, through contact with Alan Hildebrand in 1990, Penfield obtained samples that suggested it was an impact feature. Evidence for the impact origin of the crater includes shocked quartz , a gravity anomaly , and tektites in surrounding areas. In 2016, a scientific drilling project drilled deep into

3726-620: The major coal basins in Queensland and New South Wales, with further potential resources in South Australia. Commercial recovery of coal seam gas (CSG) began in Australia in 1996. As of 2014, coal seam gas, from Queensland and New South Wales, made up about ten percent of Australia's gas production. Demonstrated reserves were estimated to be 33 trillion cubic feet (35 905 petajoules) as of January 2014. In Canada, British Columbia

3795-424: The methane composition of the coalbed gas is less than 92%, it may not be commercially marketable. As with all carbon-based fossil fuels, burning coalbed methane releases carbon dioxide (CO 2 ) into the atmosphere. Its effect as greenhouse gas was first analyzed by chemist and physicist Svante Arrhenius . CBM production also entails leaks of fugitive methane into the atmosphere. Methane is rated as having 72 times

3864-525: The most recent dating of the Deccan Traps supports the idea that rapid eruption rates in the Deccan Traps may have been triggered by large seismic waves radiated by the impact. Coalbed methane Coalbed methane ( CBM or coal-bed methane ), coalbed gas , or coal seam gas ( CSG ) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Australia, and other countries. The term refers to methane absorbed into

3933-622: The observed level of ammonite extinction. The regression would also have caused climate changes, partly by disrupting winds and ocean currents and partly by reducing the Earth's albedo and therefore increasing global temperatures. Marine regression also resulted in the reduction in area of epeiric seas , such as the Western Interior Seaway of North America. The reduction of these seas greatly altered habitats, removing coastal plains that ten million years before had been host to diverse communities such as are found in rocks of

4002-483: The permeability lies in the range of 0.1–50 milliDarcys. The permeability of fractured reservoirs changes with the stress applied to them. Coal displays a stress-sensitive permeability and this process plays an important role during stimulation and production operations . Fracture permeability in Coalbed methane reservoir tends to increase with depletion of gas; in contrast to conventional reservoirs. This unique behavior

4071-569: The public at Trinidad Lake State Park , among other places in the basin. Bituminous coal mines opened in the Raton Basin in 1873. Walsenburg, Colorado , Trinidad, Colorado and Raton, New Mexico became coal-mining towns. The coal deposits are in the Vermejo Formation ( Cretaceous ) and overlying Raton Formation (Cretaceous and Paleocene ). Most of the mines were underground room-and-pillar, although in later years some mines in New Mexico used longwall mining. Some strip mining

4140-547: The rate of formation of additional methane is undetermined. This debate is currently causing a right of ownership issue in the Canadian province of Alberta , as only non-renewable resources can legally be owned by the province. Although gas in place in Britain's coal fields has been estimated to be 2,900 billion cubic meters, it may be that as little as one percent might be economically recoverable. Britain's CBM potential

4209-520: The remaining methane. The produced water brought to the surface as a byproduct of gas extraction varies greatly in quality from area to area, but may contain undesirable concentrations of dissolved substances such as salts , naturally present chemicals, heavy metals and radionuclides . In many producing regions the water is treated, such as through a Reverse Osmosis plant and used beneficially for irrigation, water for livestock, urban and industrial uses, or dust suppression. In 2012 Eastern Star Gas

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4278-610: The reservoir The thickness of the formation may not be directly proportional to the volume of gas produced in some areas. For example, it has been observed in the Cherokee Basin in Southeast Kansas that a well with a single zone of 1 to 2 feet (0.3 to 0.6 m) of pay can produce excellent gas rates, whereas an alternative formation with twice the thickness can produce next to nothing. Some coal (and shale) formations may have high gas concentrations regardless of

4347-426: The seams from the surface, and the methane allowed to vent before mining. Coalbed methane as a natural-gas resource received a major push from the US federal government in the late 1970s. Federal price controls were discouraging natural gas drilling by keeping natural gas prices below market levels; at the same time, the government wanted to encourage more gas production. The US Department of Energy funded research into

4416-408: The solid matrix of the coal. It is called 'sweet gas' because of its lack of hydrogen sulfide . The presence of this gas is well known from its occurrence in underground coal mining, where it presents a serious safety risk . Coalbed methane is distinct from a typical sandstone or other conventional gas reservoir, as the methane is stored within the coal by a process called adsorption . The methane

4485-647: The time of the K–Pg boundary. This suggests the possibility of nearly simultaneous multiple impacts, perhaps from a fragmented asteroidal object, similar to the Shoemaker–Levy 9 cometary impact with Jupiter . Among these are the Boltysh crater , a 24 km (15 mi) diameter impact crater in Ukraine (65.17 ± 0.64 Ma); and the Silverpit crater , a 20 km (12 mi) diameter proposed impact crater in

4554-435: The view that the extinction was gradual, as the flood basalt events were thought to have started around 68 Ma and lasted for over 2 million years. However, there is evidence that two thirds of the Deccan Traps were created within 1 million years about 65.5 Ma, so these eruptions would have caused a fairly rapid extinction, possibly a period of thousands of years, but still a longer period than what would be expected from

4623-416: The world, the later ones are terrestrial; earlier ones represent shorelines and the earliest represent seabeds. These layers do not show the tilting and distortion associated with mountain building ; therefore, the likeliest explanation is a regression , that is, a buildout of sediment, but not necessarily a drop in sea level. No direct evidence exists for the cause of the regression, but the explanation which

4692-513: Was done in New Mexico. Much of the mining on the Colorado side of the basin supplied the steel mills at Pueblo, Colorado . Production through 1975 was 326 million short tons (295 million tonnes). The New Elk coal mine, inactive since 1989 and now owned by Allegiance Coal of Australia, reopened in June 2021. A number of wells have been drilled over the years seeking conventional oil and natural gas, but none has been produced in economic quantities in

4761-575: Was fined for "discharging polluting water containing high levels of salt into Bohena Creek" in the Pilliga Scrub. There were "16 spills or leaks of contaminated water" including "serious spills of saline water into woodland and a creek." In 2012, a NSW Legislative Council inquiry criticised the use of open holding ponds, recommending that "the NSW Government ban the open storage of produced water." Not all coalbed methane produced water

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