Although it is sometimes called acid mine drainage, not all abandoned mine drainage is acidic. When water flows over or through sulfurbearing mine tailings, a chemical reaction occurs between the water and rocks resulting in metalrich water. Regions where rocks have low buffering capacity generate highly acidic toxic solutions that are referred to as acid mine drainage amd. Handbook for constructed wetlands receiving acid mine drainage. Geochemistry of acid mine drainage from a coal mining area. Acid mine drainage solutions for the mineral industry. Effective treatment options for acid mine drainage in the coal region of west virginia a thesis submitted to the graduate college of marshall university in partial fulfillment of the requirements for the degree of master of science in geography by daniel kirby dr.
The origin of acidic metalrich mine drainage waters has been described in detail elsewhere e. Acid mine drainage biofilm metagenomics ncbi bookshelf. Preventing acid and metalliferous drainage department of industry. Acid mine drainage is an extensively documented environmental issue, commonly originated by the weathering of sulfide ores both in active and abandoned mining sites. National mine land reclamation center summary acid mine drainage research projects paul ziemkiewicz director national mine land reclamation center west virginia university following, is a summary of research projects supported through the national mine land reclamation center up to june 1992. This research focuses on the remediation of acid mine drainage amd using metallurgical slags. Fundamentals of minedrainage formation and chemistry. Pyrite fes2 is commonly associated with coal and metal ore deposits. The acid mine drainage amd inventory included all sites where water quality was a concern to the inspector.
The following is an overview of information on some major. In some instances, daylighting surface mining of an underground mine or past auger mining into final highwall has caused the water quality to. Ferrous or soluble iron is the first pollutant associated with acid mine drainage as it starts to make streams too acidic to support aquatic life figure 1. Total metals loading results for al from samples taken from the mine wall sampling stations. Acid mine drainage, geomicrobiology, usgs microbiology. To file a complaint of discrimination, write usda, director, office of civil rights, room 326w, whitten.
The chemicals allow copper minerals to rise to the top and stick to. Acid mine drainage heres a look at what amd is and how it affects the surrounding environment. Nov, 2019 in a nutshell, acid mine drainage is a form of water pollution that happens when rain, runoff, or streams come in contact with rock that is rich in sulfur. Acid mine drainage terms acid mine drainage amd water that is polluted from contact with mining activity acid rock drainage ard natural rock drainage that is acidic both produce acidic waters how to distinguish. Western pennsylvania was once a great coal mining region. This is a natural chemical reaction which can proceed when minerals are exposed to air and water. Stanton, 2008, bacterial processes can influence the movement of metal contaminants in wetlands that have been affected by acid drainage, chapter d in verplanck, p. The vegetation and soil work to intercept oxygen entering the subsurface. Innovative treatment technologies notice this document was prepared by a national network of environmental management studies grantee under a fellowship from the u. The objective of this phd research was to investigate the leaching of acid clays with acid minerock drainages amdard typically found in u. A study of environmental assessment of acid mine drainage. Acid mine drainage amd forms when sulfide m inerals are exposed to oxidizing conditions in coal and metal mining, highway construction, and other largescale excavations.
The acid mine drainage may also contain high amounts of co2 which forms carbonic acid and further depresses the ph. An example of acid mine drainage flowing into shamokin creek. Iron is the most common metal in abandoned mine drainage, but aluminum and manganese occur as well. The dissolution of sulfide minerals such as pyrite fes 2, arsenopyrite feass, chalcopyrite cufes 2, sphalerite zns, and marcasite fes 2 yields hot, sulfuric acidrich solutions that contain high concentrations of toxic metals. The potential impacts of acid mine drainage on bristol bay fisheries is the primary source of opposition to the proposed pebble mine in southwestern alaska and also a concern at the proposed donlin gold mine. The oxidation of sulphidic mine wastes and the consequent release of acid mine drainage and acid rock drainage, is one of the main strategic environmental issues facing the mining industry. Despite the extreme acidity, heat, and high concentrations of sulfate and toxic metals, a diverse range of microorganisms populate amd environments. Amd is caused when water flows over or through sulfurbearing materials forming solutions of net acidity. Acid mine drainage is a problem at a number of active alaskan metal mines including red dog, greens creek, and kensington mine. Mine drainage is metalrich water formed from chemical reaction between water and rocks containing sulfurbearing minerals. Acid mine drainage amd is a national problem, but onethird of waters impacted by that problem are located in pennsylvania, which, after over a century of coal extraction, has produced. Abandoned mine drainage typically has high concentrations of metals and total dissolved solids. Acid drainage influence on the water and sediment quality was investigated in a coal mining area southern brazil.
Inter ministerial committee report on acid mine drainage and. Sources of acid mine drainage mining of gold, silver, copper, iron, zinc, lead or combined metals, and coal during exploration, operation, and closure of mine, from the mines. The remnants of this industry are still with us in the form of abandoned mines that underlay a great portion of the land on which we live, and in the drainage of acidic waters from the mines into our streams and rivers. Amd or acid rock drainage ard, collectively called acid drainage ad, is acidic water ph less than 5. The regulation of acid mine drainage in south africa. Jun 17, 2016 what is acid mine drainage amd, why is it such a serious threat to south africa and more importantly why has been it been silenced and kept under wraps by the mining industry and south african government for so long. Fact sheet acid mine drainage the problem the formation of acid mine drainage and the contaminants associated with it have been described as the largest environmental problem facing the u. Acid mine water drainage debating a sustainable solution to a serious issue 7. There are four chemical reactions that represent the chemistry of pyrite weathering to form acid mine drainage. This included sites where effluent limits were not being met for any established parameter, not just ph alkalinity. Development of an ree recovery industry around pre and postlaw mines will incentivize capture of these drainage sources, treatment of amd and discharge of clean water. In brief, the major cause is the accelerated oxidation of iron pyrite fes 2 and.
A bench scale evaluation of organic substrates for use in constructed wetlands for the treatment of acid mine drainage 1991 197432284. Acid mine drainage amd is typically characterized by low ph and high dissolved iron. Research efforts have proceeded recently through the acid drainage technology initiative. In some instances, daylighting surface mining of an underground mine or past auger mining into final highwall has caused the water quality to change from highly acidic to highly alkaline. In most cases, this acid comes primarily from oxidation of iron sulfide fes2, also known as pyrite or fools gold, which is often found in conjunction with valuable metals. Problems associated with mine drainage contaminated drinking water disrupted growth and reproduction of aquatic plants and animals corroding effects of acid on parts of infrastructure such as bridges acid mine drainage mines built as early as the 1800s were developed in a manner which utilized gravity drainage, to avoid excessive water accumulation in the mines. Many streams derived from acid mine drainage are largely devoid of life for a. Acid mine drainage amd refers to the outflow of acidic water from a mining site. In locations where access of oxidants to sulfide mineral surfaces is increased by mining, the resulting acid mine drainage amd may contaminate. Fifth international conference on acid rock drainage, denver, colorado.
As a result, the water becomes very acidic and damages downstream aquatic ecosystems. Effects of acid mine drainage on the release of aluminum. There are four chemical reactions that represent the chemistry of pyrite weathering to. The major areas of research on amd are prediction of amd and preventionmitigation. Amd is a legacy left behind by abandoned, derelict and defunct mines, and is a continuing byproduct of existing mining.
The title is a misnomer, and the resulting document should be referred to as the. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments. Abandoned mine drainage typically originates in surface mines, deep mines, and gob piles. Reclamation can include plugging old mine addits and removal, isolation, or burial. Acid mine water drainage debating a sustainable solution to a serious issue 3. Major environmental incidents caused by acid mine drainage. In colorado alone there are over 30,000 abandoned mines. The high acidity of acid mine drainage and the high amounts of dissolved heavy metals such as copper and zinc generally make acid mine drainage extremely toxic to most organisms pentreath, 1994. Characteristics increased acidity decreased ph increased metal concentrations increased sulfate increased suspended solids all.
Treating acid mine drainage from abandoned mines in remote areas john j. Recovery of rare earth elements rees from coal mine drainage. This paper describes acid mine drainage amd generation and its associated technical issues. What is acid mine drainage amd, why is it such a serious threat to south africa and more importantly why has been it been silenced and kept under wraps by the mining industry and south african government for so long. Amd comes mainly from abandoned coal mines and currently active mining.
Acid mine drainage amd is arguably one of the most serious environmental concerns in south africa. This was achieved by the determination of some physicochemical properties and anion abundance in the water, the investigation of some heavy metal levels in the water and sediments, and the potential risks of sediment bound heavy metals to biota. In a nutshell, acid mine drainage is a form of water pollution that happens when rain, runoff, or streams come in contact with rock that is rich in sulfur. Effective treatment options for acid mine drainage in the. Abandoned mine drainage also known as amd is a form of water pollution involving water that has been polluted by contact with mines, typically coal mines. Acid mine drainage is the second most important source of stream impairment in the appalachian basin. Acid mine drainage is a major problem with many hardrock mines. Reclamation can include plugging old mine addits and removal, isolation, or burial of tailings piles. As amd is recognized as one of the more serious environmental problems in the mining industry, its causes, prediction and treatment have become the focus of a number of research initiatives commissioned by governments, the mining industry, universities and research establishments, with additional.
Acid mine drainage amd is a national problem, but onethird of waters impacted by that problem are located in pennsylvania, which, after over a century of coal extraction, has produced more coal tonnage than any other state in the u. The production of broken waste rock and tailings by mining operations can expose large amounts of pyrite and other sulphides to the effects of water and oxygen. Because acid mine drainage can destroy a streams aquatic community for miles, many of the old mining sites are being reclaimed. Jul 11, 20 sources of acid mine drainage mining of gold, silver, copper, iron, zinc, lead or combined metals, and coal during exploration, operation, and closure of mine, from the mines. Many streams derived from acid mine drainage are largely devoid of life for a long way downstream. Comparison of acid rock drainage factors in waste rock piles and tailings. Summitville mine rio grande headwaters elevation 12,800 snowfall. Heavy metals emanating from former mine sites are a major threat to water resources. Department of the interior colorado school of mines u. Slag leach beds are a promising low cost and low maintenance technology for the remediation of amd compared to potentially expensive and maintain once intensive conventional active methods that entail addition of chemicals to treat amd. Treating acid mine drainage from abandoned mines in. Acid mine drainage amd occurs when metal sulfides, most commonly pyrite, are exposed to and react with air and water. In pennsylvania, reported aluminum concentrations in discharge samples from 140 abandoned coal mines showed that over.
Acid mine drainage amd is currently the main pollutant of surface water in the midatlantic region. The legacy issues surrounding the problem the issue of accountability although south africa has a long history of mining, the. Treating acid mine drainage from abandoned mines in remote. Its generation, release, mobility, and attenuation involves complex processes governed by a combination of physical, chemical, and biological factors. Acid mine drainage prevention and control options nural kuyucak golder associates ltd. In examining this table, it is important to note that diffusion of oxygen into water is slow and, therefore, oxidation of iron sulfide is inhibited until the water level drops, which can occur periodically or seasonally in some cases. Building, 14th and independence avenue, sw, washington. Access to pdf files requires adobe reader or an alternate pdf. Acid mine drainage amd is an acidic, sulfurrich, metallic wastewater, originating from mine discharge of both operational and abandoned mines 1. This is a natural chemical reaction which can proceed. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2. Inter ministerial committee report on acid mine drainage. Acid mine water drainage debating a sustainable solution.
A team of experts has been instructed by a task team, chaired by the directors. Metesh hydrogeologist terrie jarrell project leader steve oravetz program leader usda forest service technology and development program missoula, montana 7e72g71 acid mine drainage study october 1998 united states department of agriculture forest service technology. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s. Acid mine drainage amd or acid rock drainage ard is considered as one of the main pollutants of water in many countries that have historic or current mining activities. Acid mine drainage, acid and metalliferous drainage amd, or acid rock drainage ard is the outflow of acidic water from metal mines or coal mines acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by largescale earth disturbances characteristic of mining and other large construction activities, usually within rocks. Ndwp, 2001, humboldt river chronology pdf document. The life cycle of acid mine drainage copper ore from arizona concentrating ground up rock is mixed with water, air bubbles and small amounts of chemicals. Environmental notes on mining, updated september 2009. Acid mine drainage amd is the flow, or seepage, of polluted water from old mining areas. C oxygen, water and pyrite react to form sulfuric acid and in turn dissolve metals from the rocks. Prevention of acid mine drainage generation from open. Media in category acid mine drainage the following 51 files are in this category, out of 51 total.
In some regions, it is the most common form of stream and river pollution. Sulfatereducing bacteria srb present a natural way to reverse the damage caused by acid mine drainage. Active treatment of mine water to provide water for site use and for. Wildeman billings symposium asmr annual meeting assessing the toxicity potential of mine waste piles workshop june 1, 2003 u. Additionally, acid mine drainage coats stream bottoms with iron hydroxide, giving the subtrates in impacted streams an orange color.