Addressing acid mine drainage improves water quality in black branch and cane creek waterbodies improved high acidity in discharge from abandoned mines led to increased metal levels and low ph in black branch and cane. The following is an overview of information on some major. Dewatering and groundwater control is an important part of many open pit and underground mines. The mining industry has felt the burden of both negative environmental criticism and strong governmental regulations. Treatment must ensure local discharge regulationsstandards are met, so disposal to surface water or reinjection into aquifer is possible. Lopaschuk, geologicalgeotechnical engineer, cyprus anvil mining corporation, faro, yukon territory, canada there have been many problems associated with drainage control and mine dewatering since mining started at the faro open pit mine. Abandoned mine sites are prevalent throughout the state of colorado. Effective treatment options for acid mine drainage in the. Pdf mine water quality deterioration due to acid mine. Initial water analyses should include ph, conductivity, alkalinity, iron, manganese, and acidity measurements hedin and others 1994. This may be the biggest challenge of all the unknown. Poorly controlled groundwater will waste money, slow down.
Using fes 2 as an example, amd for mation can be represented as follows. 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. Treating acid mine drainage from abandoned mines in remote. In the past, mineral extraction and processing has been a source of many contaminants entering our water, soil, and air. This paper focusses on the description of reliable, safe and economical treatment of mine water from different types of mines and applications by advanced membrane systems. Acid mine drainage control can be undertaken where. This document describes the purpose and implementation of the abandoned mines water quality study. Acid mine drainage amd, remediation, wetlands, minewater chemistry introduction. 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. When mine and mine waste drainage have neutral ph, with a high concentration of dissolved metals, they are called neutral or alkaline mine drainage lottermoser, 2010. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments. Geochemistry of ground water in mine drainage a3 the range of eh for mine waters having activities of ferrous ion between 10 ppm and 1,000 ppm in equilib rium with fe oh3 has been calculated and is shown in figure 1.
Drainage control and mine dewatering at faro open pit mine abstract by randy s. The water can become contaminated with high concentrations of dissolved. Surface water must also be controlled to allow efficient mining operations. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage. Acid mine drainage abandoned and active mines are a major pollution concern. The pyrite undergoes oxidation in a twostage process, the.
Geochemistry of ground water in mine drainage problems. On some projects groundwater is a minor impediment that can be dealt with on an adhoc basis. 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. Acid mine drainage solutions for the mineral industry. The major areas of research on amd are prediction of amd and preventionmitigation. Upon exposure to water and oxygen, sulfide minerals oxidize to form acidic, sulfaterich. The design of the systems follows guidance presented by us bureau of mines information circular 9389, passive treatment of coal mine drainage hedin, nairn, and kleinmann 1994. Pdf acid mine drainage control and treatment researchgate.
Understanding mine water treatment mine water, acid mine drainage and ochre as coal mining in the uk has reduced, some arrangements to pump water out of the mines have stopped. 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. Guideline document for monitoring acid mine drainage, october. Potential impacts associated with acid mine drainage are considered to be one of the greatest environmental problems faced by the mining industry today feasby et al. Environmental assessment of acid mine drainage pollution on surface water bodies around ngwenya mine, swaziland. Drainage control and mine dewatering at faro open pit mine. Recovery of rare earth elements rees from coal mine drainage. Costs in 2000 of five chemicals to treat acid mine drainage in west virginia.
Development of an ree recovery industry around pre and postlaw mines will incentivize capture of these drainage sources, treatment of amd and discharge of. The mine drainage water emanating from various collieries are highly acidic in character and. Addressing acid mine drainage improves water quality in black. Mine water treatment solutions for discharge and reuse. As a result, black branch and cane creek were added. The acid mine drainage waste is characterized by red water. Water quality impacts from these abandoned mines is a longtime concern. 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. In coalmining areas, the most common of these minerals is iron pyrite fes 2.
Technology data sheet mine dewatering groundwater eng. Aug 16, 2015 the formation of acid mine drainage amd, a highly acidic and metalrich solution, is the biggest environmental concern associated with coal and mineral mining. There are four main types of mining impacts on water quality. Evolution of mine drainage in coon creek west of rip van winkle mine. Acid mine drainage amd refers to the outflow of acidic water from a mining site. Acid mine drainage the center for rural pennsylvania. 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. Formation, intrusion, dewatering well, mine drainage, tailings water, or mineral processing water can be treated for reuse or discharge. This has allowed iron, found in the rocks within mine workings, to mix with underground water.
Efforts by federal, state, and local entities to assess and address pollution is an ongoing effort. As a result, the water becomes very acidic and damages downstream aquatic ecosystems. A key aspect of mine dewatering systems is that they will generate water from pumped wells or sumps, from flowing drains, and from surface water collection systems. The origin of acidic metalrich mine drainage waters has been described in detail elsewhere e.
Recovery of rare earth elements rees from coal mine. The origin of acid mine drainage acid mine drainage also sometimes referred to as acid rock drainage is a wellunderstood process2 and arises primarily when the mineral pyrite fools gold or iron disulphide comes into contact with oxygenated water. Guideline document for monitoring acid mine drainage. The formation of acid mine drainage amd, a highly acidic and metalrich solution, is the biggest environmental concern associated with coal and mineral mining. Passive treatment of coal mine drainage office of surface. Scientific investigations report 20045291, available online and. Constructed wetlands for treating acid mine drainage. In most cases, this acid comes primarily from oxidation of iron. One reason that pyrite is important in amd generation is that it forms under a variety of conditions and is widespread in different rock types. Amd pollution causes the release of heavy metals into the environment 10, rendering them available for intake by. Acid mine drainage acid rock drainage ard is a natural process whereby sulphuric acid is produced when sulphides in rocks are exposed to air and water. Passive treatment of acidmine drainage vtechworks virginia.
Water quality deterioration due to acid mine drainage is of concern in the northeastern coalfield of india as the water in this area is severely polluted. Acid mine drainage in south africa amazon web services. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine. Amd is caused when water flows over or through sulfurbearing materials forming solutions of net acidity. Water control in underground mines grouting or drainage. Major environmental incidents caused by acid mine drainage 7. Mine dewatering is the action of removing groundwater from a mine. In other mines, and in other geological settings, dewatering is fundamental to the viability of the mine and may require the use. Hence, implementations of effective postmining management practices are. This is a natural chemical reaction which can proceed. Environmental assessment of acid mine drainage pollution. 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. Once produced, amd can severely impact the surrounding ecosystem due to its acidity, metal toxicity, sedimentation and other deleterious properties.
Acid mine water drainage debating a sustainable solution to a. Coal mine drainage prediction and pollution prevention in penn. Anoxic limestone drains are buried beds limestone that are intended to add bicarbonate alkalinity to flowthrough acid mine drainage. Acid mine drainage acid drainage occurs when minerals containing reduced forms of sulfur s oxidize via exposure to oxygen and water during earth disturbances figure 1. Pdf acid mine drainage formation, control and treatment. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s. The analysis is based on a fiveyear operation period and includes chemical reagent costs, installation and. One reason that pyrite is important in amd generation is that it forms under a variety of conditions and. Acid minerock drainage center for water, earth science. Hence, implementations of effective postmining management practices are necessary to. Passive treatment of coal mine drainage by robert s. Amd is formed when mining activities fracture the bedrock that is situated over coal seams, allowing rain and ground water to percolate through the overburden and bringing the rock into contact with water. Acid mine drainage amd occurs primarily when the mineral ore pyrite fes 2 is exposed to water and oxygen from air, producing soluble iron and sulfuric acid. In brief, the major cause is the accelerated oxidation of iron pyrite fes 2 and.
Acid minerock drainage center for water, earth science and. Runoff from the surrounding land surface must be diverted away from the mine, for example by using collector drains and diversion bunds. As this mine water reaches the surface it comes into contact with the air. The simplest treatment is neutralization and clarification. Dec 17, 2016 there are four main types of mining impacts on water quality. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2. Acid mine drainage amd forms when sulfide minerals, particularly pyrite and marcasite, have been exposed to oxidizing conditions during mining and other excavation activities, such as highway. The ideal neutralization first combines one of the reactants with previously precipitated solids. Some of this water will be dirty water and will require some form of treatment most commonly to remove suspended solids before it can be used or disposed of. Mine water quality deterioration due to acid mine drainage. Mining and water pollution safe drinking water foundation. The objective of the water management plan mine is to describe a safe and reliable system for managing the water at the mine site in a manner that results in compliance with applicable surface water and groundwater quality standards at appropriate mine site compliance points as demonstrated by modeling outcomes discussed in reference 2. 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.
Failure to properly monitor, collect, and treat amd can lead to contamination of groundwater and surface water. Within a mine any surface water must be controlled by the drains and sumps to collect the water away from working areas. Major environmental incidents caused by acid mine drainage. Mine drainage is formed when pyrite an iron sulfide is exposed and reacts with air and water to form sulfuric acid and dissolved iron. The water treatment performances of two anoxic limestone drains alds were evaluated. Mines should be able to use human rights rhetoric and additional contextual analysis to better understand how social impact issues can evolve into potential human rights violations. Since 1994 he has designed 47 passive treatment systems that have been installed largely in pennsylvania.
The applications include mine drainage water from underground mines, intrusion water in open pit mines and excess water from tailing storage facilities. Mine drainage is formed when pyrite, an iron sulfide, is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Use of polluted water upsets the whole ecological system 912. The mine drainage water emanating from various collieries are highly acidic in character and contain high hardness, sulphate, total dissolved solids and iron coupled with low ph valueswhich further results in contamination of trace heavy. When a mine extends below the water table groundwater will, due to gravity, infiltrate the mine workings. When the rocks made of sulfur are excavated from a mine surface or an underground mine, they. Acid mine drainage is the second most important source of stream impairment in the appalachian basin. Percola tion of water through these materials results in a discharge with low ph and high metals concentration. The water that is impacted by acid mine drainage must be treated in order to stop any more problems from starting in the stream or river and to help reverse any effects that have already occurred in the area where the drainage is entering the water. Addressing acid mine drainage improves water quality in. The acid runoff further dissolves heavy metals such as copper, lead, and. Research efforts have proceeded recently through the acid drainage technology initiative. Compared with conventional chemical treatment, passive methods.