Abandoned mine drainage (also known as AMD [1] ) is a form of water pollution involving water that has been polluted by contact with mines, typically coal mines. [2] Although it is sometimes called "acid mine drainage", not all abandoned mine drainage is acidic. [3] [4]
The most common form of abandoned mine drainage is acid mine drainage, which is highly acidic water coming from mines. [2] Abandoned mine drainage can become acidic when it is exposed to oxygen and sulfur-containing minerals such as pyrite. [5]
Another form of abandoned mine drainage is alkaline mine drainage. [2] This typically occurs in the presence of minerals such as calcite, limestone, or dolomite. [2] [6] The third form of abandoned mine drainage is metal mine drainage, which occurs when large amounts of metals such as lead contaminate mine water. [2]
The precise chemistry of abandoned mine drainage discharges typically varies. [4] Abandoned mine drainage typically originates in surface mines, deep mines, and "gob piles". [6]
Abandoned mine drainage typically has high concentrations of metals and total dissolved solids. [5] Iron is the most common metal in abandoned mine drainage, but aluminium and manganese occur as well. [3] It may also have a high water temperature and an altered pH, though the characteristics of abandoned mine drainage depend heavily on the area's geochemistry. [5] Other signs of abandoned mine drainage include high sulfate levels and siltation. [3] Acid mine drainage has a pH of less than 7, while alkaline mine drainage has a pH of greater than 7. [1]
The concentrations of metals in abandoned mine drainage can range from several to several thousand parts per million. In Pennsylvania's Coal Region, it has an iron concentration of less than 100 milligrams per liter (0.100 oz/cu ft) and a pH of close to 7. [1]
Abandoned mine drainage can cause affected streams to take on a bright orange color. [7]
Abandoned mine drainage affects streams worldwide. [8] A 2017 United Nations Environmental Programme (UNEP) report documented "widespread destruction" from mining waste that is released into the environment as a result of dam failures. [9]
Mine drainage is prevalent in the United States state of Pennsylvania, as well as several other states that have historically had large mining industries. [2] In Pennsylvania, nearly 2,500 miles (4,000 km) of streams have been affected by abandoned mine drainage, and more than 7,500 miles (12,100 km) have been affected in the Appalachian Mountains, and more than 10,000 miles (16,000 km) are affected in Pennsylvania and West Virginia. [10] [3] [7]
In one watershed affected by abandoned mine drainage, the value of homes within 200 feet (61 m) of an affected stream decreased by $2500 per 1 acre (0.40 ha), as of 2009. [3]
Algae sometimes coat streams that are affected by abandoned mine drainage, although aquatic plants have difficulty surviving in such streams. The gills of fish are also harmed by the metals in abandoned mine drainage. The eggs of macroinvertebrates and fish are also smothered by the precipitate. Coldwater fish such as trout are especially harmed by abandoned mine drainage. [3]
Abandoned mine drainage also affects the plants and animals in the area surrounding the mine. Mine drainage pollution has been found in sheep that fed near abandoned mines. [11]
There are several methods by which abandoned mine drainage can be remedied: passive treatment, active treatment, and land reclamation. [3] Trompes may also be useful in treating abandoned mine drainage. [12]
The natural gas industry has suggested using abandoned mine drainage water in hydraulic fracturing. [13] Proponents of this idea say that it would remove toxic water from the environment while reducing the natural gas industry's need to use water from streams and rivers. However, opponents have said that it would "make a dirty process even dirtier". This has already been done with streams such as an unnamed tributary to Johnson Creek. [14] Abandoned mine drainage solids have shown potential in capturing mercury emissions from coal-fired power plants. [15]
The iron oxide generated by treating abandoned mine drainage can be used as a glaze for pottery. [16]
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.
Kettle Creek is a tributary of the West Branch Susquehanna River running through Tioga, Potter, and Clinton counties, in Pennsylvania. It is slightly less than 43 miles (69 km) long. Although many streams in the Kettle Creek watershed are considered "Class A Wild Trout streams" by the Pennsylvania Fish and Boat Commission, the lower reaches of the stream experience acid mine drainage. The upper reaches of the creek are considered to be very high-quality.
The health and environmental impact of the coal industry includes issues such as land use, waste management, water and air pollution, caused by the coal mining, processing and the use of its products. In addition to atmospheric pollution, coal burning produces hundreds of millions of tons of solid waste products annually, including fly ash, bottom ash, and flue-gas desulfurization sludge, that contain mercury, uranium, thorium, arsenic, and other heavy metals. Coal is the largest contributor to the human-made increase of carbon dioxide in Earth's atmosphere.
Environmental effects of mining can occur at local, regional, and global scales through direct and indirect mining practices. The effects can result in erosion, sinkholes, loss of biodiversity, or the contamination of soil, groundwater, and surface water by the chemicals emitted from mining processes. These processes also affect the atmosphere from the emissions of carbon which have an effect on the quality of human health and biodiversity. Some mining methods may have such significant environmental and public health effects that mining companies in some countries are required to follow strict environmental and rehabilitation codes to ensure that the mined area returns to its original state.
Coal mining in Brazil is the country's largest source of non-renewable energy, and is an important part of Brazil's energy economy. Brazil is the tenth largest energy consumer and the third largest in the Western Hemisphere. Coal accounts for approximately 5.8 percent of the country's total primary energy supply. It is the country's largest source of non-renewable energy, followed by nuclear energy, petroleum, and natural gas. Brazil produces about 6 million tons of coal per year, and total coal reserves are estimated at approximately 32.3 billion tons. It is also important in reducing reliance on imported oil and gas.
The Audenried Tunnel is a drainage tunnel located in East Union Township, Schuylkill County, Pennsylvania, in the United States. It is approximately three miles long and drains the western portion of a coal basin near Kelayres. It is among the largest sources of acid mine drainage into Catawissa Creek. It also contributes up to 80% of the acidity to Catawissa Creek. The Audenried Tunnel's pH is approximately 4. However, there have been somewhat successful attempts at treating the tunnel outflow in the 21st century. The bedrock in the vicinity of the tunnel is mostly shale and sandstone.
Solomon Creek is a tributary of the Susquehanna River in Luzerne County, Pennsylvania, in the United States. It is approximately 8.8 miles (14.2 km) long and flows through Fairview Township, Hanover Township, and Wilkes-Barre. The creek is affected by acid mine drainage and has significant loads of iron, aluminum, and manganese. The creek's named tributaries are Spring Run, Sugar Notch Run, and Pine Creek. The Solomon Creek watershed is located in the Anthracite Valley section of the ridge-and-valley geographical province. Major rock formations in the watershed include the Mauch Chunk Formation, the Spechty Kopf Formation, and the Catskill Formation.
Drury Run is a tributary of the West Branch Susquehanna River in Clinton County, Pennsylvania, in the United States. It is 7.71 miles (12.41 km) long and its watershed is 11.5 square miles in area, most of which is forest. The stream's tributaries are affected by acid mine drainage, as are the lower reaches of the stream itself. It begins in Tamarack Swamp and flows through Leidy Township, Noyes Township, and Renovo. Brook trout, brown trout, creek chub, and eastern blacknose dace all inhabit the stream.
Twomile Run is a tributary of Kettle Creek in Clinton County, Pennsylvania, in the United States. It is 4.5 miles (7.2 km) long. Tributaries of the stream include Huling Branch and Middle Branch Twomile Run. The stream flows through Leidy Township and Noyes Township. The stream's watershed has an area of approximately 9 square miles. Coal is mined in the watershed. Most of the acid mine drainage in Kettle Creek comes from Twomile Run.
Cranberry Creek is a tributary of Stony Creek in Luzerne County, Pennsylvania, in the United States. It is approximately 4.4 miles (7.1 km) long and flows through Hazle Township. The creek is affected by acid mine drainage. It also contains metals such as iron, manganese, and aluminum. It is in the drainage basin of the Jeddo Tunnel. Major roads in the creek's watershed include Pennsylvania Route 924, Pennsylvania Route 309, and Interstate 81. At least one bridge has been built over it. The creek has undergone restoration and there are plans to construct an area known as the Cranberry Creek Gateway Park in its vicinity.
Sugar Notch Run is a tributary of Solomon Creek in Luzerne County, Pennsylvania, in the United States. It is approximately 3.0 miles (4.8 km) long and flows through Hanover Township, Sugar Notch, and Ashley. The watershed of the stream has an area of 2.33 square miles (6.0 km2). The stream is considered to be impaired by abandoned mine drainage for its entire length. Brook trout and various macroinvertebrate taxa inhabit portions of the stream and it is designated as a Coldwater Fishery. Coal mining has historically been done in the watershed and a small intake dam was on the stream in the early 1900s. Recreational opportunities in the watershed include the Sugar Notch Trail System and Pennsylvania State Game Lands Number 207.
Nanticoke Creek is a tributary of the Susquehanna River in Luzerne County, Pennsylvania, in the United States. It is approximately 4.4 miles (7.1 km) long and flows through Hanover Township and Nanticoke. The watershed of the creek has an area of 7.57 square miles (19.6 km2). The creek has one named tributary, which is known as Espy Run. Nanticoke Creek impaired by pH and metals due to abandoned mine drainage. Abandoned mine drainage discharges in the creek's watershed include the Truesdale Mine Discharge and the Askam Borehole. The creek is located in the Northern Middle Anthracite Field and is in the Anthracite Valley Section of the ridge and valley physiographic province. The main rock formations in the watershed include the Mauch Chunk Formation, the Pottsville Group, and the Llewellyn Formation. The surficial geology consists of coal dumps, surface mining land, alluvium, Wisconsinan Outwash, Wisconsinan Till, urban land, and bedrock.
Operation Scarlift was a program carried out by the Pennsylvania government in the 1960s and 1970s. Its mission was to repair environmental damage caused by abandoned mine lands, acid mine drainage, and other issues associated with historic mining. The operation began around the time that the Land and Water Conservation and Reclamation Act was passed and became inactive in the 1970s due to a lack of funding. During the operation, a total of $141,000,000 was spent on a variety of tasks, including remedying pollution in hundreds of streams, extinguishing dozens of mine fires, and constructing acid mine drainage treatment plants. Numerous reports on mining-impacted streams were produced during the operation, many of which continue to be used for assessing watersheds.
The Askam Borehole is a borehole that is located in Luzerne County, Pennsylvania, in the United States. It is situated in the watershed of Nanticoke Creek north of PA 29 and Dundee Road and contributes several million gallons of acid mine drainage to that creek daily. The borehole also discharges large loads of iron and other substances. It was constructed by the Pennsylvania Department of Environmental Protection in the early 1970s and drains mine water from the South-East Mine Pool Complex. The discharges of the borehole have been treated by active treatment systems and artificial wetlands.
Aylesworth Creek is a tributary of the Lackawanna River in Lackawanna County, Pennsylvania, in the United States. It is approximately 4.9 miles (7.9 km) long and flows through Carbondale Township and the boroughs of Mayfield and Archbald. The watershed of the creek has an area of 6.73 square miles (17.4 km2). Part of the creek is impaired by abandoned mine drainage and/or resource extraction. The creek tends to be slightly acidic, but its iron, manganese, and aluminum concentrations do not need reduction to meet its total maximum daily load requirements. Its watershed is in the Appalachian Mountain section of the ridge and valley physiographic province. The headwaters of the creek are in the Moosic Mountains. The rock formations in the watershed mainly consist of interbedded sedimentary rock and sandstone.
Wilson Creek is a tributary of the Lackawanna River in Lackawanna County, Pennsylvania, in the United States. It is approximately 3.7 miles (6.0 km) long and flows through Fell Township. The watershed of the creek has an area of 3.82 square miles (9.9 km2). The creek is impaired by metals and pH from abandoned mine drainage. Some reaches of it also experience total flow loss. There are three discharges of acid mine drainage entering the creek: the Upper Wilson Outfall, the Lower Wilson Outfall, and the Molensky Slope Outfall. The watershed of the creek is in the Appalachian Mountain section of the Ridge and Valley physiographic province. The main rock types in the watershed are interbedded sedimentary rock and sandstone. The creek flows past areas of disturbed mining land.
Carbon Run is a tributary of Shamokin Creek in Northumberland County, Pennsylvania, in the United States. It is approximately 5.2 miles (8.4 km) long and flows through Zerbe Township, Coal Township, and Shamokin. The watershed of the stream has an area of 8.78 square miles (22.7 km2). Carbon Run is impaired due to metals from acid mine drainage, which colors the stream orange. Metals such as manganese, iron, aluminum, and others occur within its water. The watershed of the stream is in the Coal Region of Pennsylvania. Much of the area in the vicinity of the stream consists of spoil piles and abandoned mining land.
Coal Run is a tributary of Shamokin Creek in Northumberland County, Pennsylvania, in the United States. It is approximately 4.7 miles (7.6 km) long and flows through Mount Carmel Township, Coal Township, and Shamokin. The watershed of the stream has an area of 6.25 square miles (16.2 km2). The stream is designated as an impaired waterbody due to metals from abandoned mine drainage. It is an ephemeral stream. Virtually all of the watershed is in coal mining regions.
According to a survey completed by the Colorado Geological Survey between 1991 and 1999, the number of abandoned mines in Colorado is 18,382. The Arkansas Headwaters, Las Animas River, Rio Grande Headwaters, Alamosa, and Uncompahgre were the priority watersheds studied in this survey. In the survey, analysis was completed with Environmental Degradation Measures ranging from none to extreme. Results showed 26 abandoned mines with extreme degradation and mineral hazards, 219 with significant degradation, and 672 potentially significant hazards.