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, burning coal produces hundreds of millions of tons of solid waste products annually, including fly ash,RadTown USA | US EPA 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.
There are severe health effects caused by burning coal. Worldwide 25 people die early for each terawatt hour of electricity generated by coal, around a thousand times more than nuclear or solar.
In addition, there have been many coal mining disasters, although work related coal deaths has declined substantially as safety measures have been enacted and underground mining has given up market share to surface mining. Underground mining hazards include suffocation, gas poisoning, roof collapse and gas explosions. Open cut hazards are principally mine wall failures and vehicle collisions. Hundreds of people died in coal mine accidents in 2022.
Land use management
Impact to land and surroundings Strip mining severely alters the landscape, which reduces the value of the natural environment in the surrounding land. The land surface is dedicated to mining activities until it can be reshaped and reclaimed. If mining is allowed, resident human populations must be resettled off the mine site; economic activities, such as agriculture or hunting and gathering food and medicinal plants are interrupted. What becomes of the land surface after mining is determined by the manner in which the mining is conducted. Usually reclamation of disturbed lands to a land use condition is not equal to the original use. Existing land uses (such as livestock grazing, crop and timber production) are temporarily eliminated in mining areas. High-value, intensive-land-use areas like urban and transportation systems are not usually affected by mining operations. If mineral values are sufficient, these improvements may be removed to an adjacent area.
Strip mining eliminates existing vegetation, destroys the genetic soil profile, displaces or destroys wildlife and habitat, alters current land uses, and to some extent permanently changes the general topography of the area mined.U.S. Department of the Interior. 1979. Permanent Regulatory Program Implementing Section 01(b) of the Surface Mining Control and Reclamation Act of 1977: Environmental Impact Statement. Washington, D.C. Adverse impacts on geological features of human interest may occur in a coal strip mine. Geomorphic and geophysical features and outstanding scenic resources may be sacrificed by indiscriminate mining. Paleontological, cultural, and other historic values may be endangered due to the disruptive activities of blasting, ripping, and excavating coal. Stripping of overburden eliminates and destroys archeological and historic features, unless they are removed beforehand.Squillace, Mark. The Strip Mining Handbook: A Coalfield Citizens' Guide To Using The Law To Fight Back Against The Ravages Of Strip Mining And Underground Mining , Washington, D.C.: Environmental Policy Institute, Friends of the Earth, 1990.United States Department of the Interior. Coal: Construction and Mining Impacts , Washington, D.C.: Office of Indian Energy and Economic Development, Tribal Energy and Environmental Information Clearinghouse (TEEIC). Retrieved 9 March 2012.
The removal of vegetative cover and activities associated with the construction of haul roads, stockpiling of topsoil, displacement of overburden and hauling of soil and coal increase the quantity of dust around mining operations. Dust degrades air quality in the immediate area, has an adverse impact on vegetative life, and constitutes health and safety hazards for mine workers and nearby residents.
Surface mining disrupts virtually all aesthetic elements of the landscape. Alteration of land forms often imposes unfamiliar and discontinuous configurations. New linear patterns appear as material is extracted and waste piles are developed. Different colors and textures are exposed as vegetative cover is removed and overburden dumped to the side. Dust, vibration, and diesel exhaust odors are created (affecting sight, sound, and smell). Residents of local communities often find such impacts disturbing or unpleasant. In case of mountaintop removal, tops are removed from mountains or hills to expose thick coal seams underneath. The soil and rock removed is deposited in nearby valleys, hollows and depressions, resulting in blocked (and contaminated) waterways.
Removal of soil and rock overburden covering the coal resource may cause burial and loss of topsoil, exposes parent material, and creates large infertile wastelands. Soil disturbance and associated compaction result in conditions conducive to erosion. Soil removal from the area to be surface-mined alters or destroys many natural soil characteristics, and reduces its biodiversity and productivity for agriculture. Soil structure may be disturbed by pulverization or aggregate breakdown.
In response to negative land effects of coal mining and the abundance of abandoned mines in the US the federal government enacted the Surface Mining Control and Reclamation Act of 1977, which requires reclamation plans for future coal mining sites. These plans must be approved by federal or state authorities before mining begins.
Mine collapses Mine collapses (or mine subsidences) have the potential to produce major effects above ground, which are especially devastating in developed areas. German underground coal-mining (especially in North Rhine-Westphalia) has damaged thousands of houses, and the coal-mining industries have set aside large sums in funding for future subsidence damages as part of their insurance and state-subsidy schemes. In a particularly spectacular case in the German Saar region (another historical coal-mining area), a suspected mine collapse in 2008 created an earthquake measuring 4.0 on the Richter magnitude scale, causing some damage to houses. Previously, smaller earthquakes had become increasingly common and coal mining was temporarily suspended in the area.
Water management Surface mining may impair groundwater in numerous ways: by drainage of usable water from shallow aquifers; lowering of water levels in adjacent areas and changes in flow direction within aquifers; contamination of usable aquifers below mining operations due to infiltration (percolation) of poor-quality mine water; and increased infiltration of precipitation on spoil piles. Where coal or carbonaceous shale is present, increased infiltration may result in: increased runoff of poor-quality water and erosion from spoil piles, recharge of poor-quality water to shallow groundwater aquifers and poor-quality water flow to nearby streams.
The contamination of both groundwater and nearby streams may be for long periods of time. Deterioration of stream quality results from acid mine drainage, toxic trace elements, high content of dissolved solids in mine drainage water, and increased sediment loads discharged to streams. When coal surfaces are exposed, pyrite comes in contact with water and air and forms sulfuric acid. As water drains from the mine, the acid moves into the waterways; as long as rain falls on the mine tailings the sulfuric-acid production continues, whether the mine is still operating or not. Also waste piles and coal storage piles can yield sediment to streams. Surface waters may be rendered unfit for agriculture, human consumption, bathing, or other household uses.
There are five principal technologies used to control water flow at mine sites: diversion systems, ash ponds (surface impoundments), groundwater pumping systems, subsurface drainage systems, and subsurface barriers.
In the United States, due to few federal and state regulations concerning ash ponds, most power plants do not use geomembranes, leachate collection systems, or other flow controls often found in municipal solid waste landfills. EPA promulgated more stringent requirements for ash ponds and landfills in its first national regulation in 2015.EPA. "Hazardous and Solid Waste Management System; Disposal of Coal Combustion Residuals From Electric Utilities." , 2015-04-17. In response to litigation, EPA published final regulations for ash ponds in 2020, requiring unlined ponds to be retrofitted with liners, or using alternatives to ponds for managing ash wastes.EPA. "Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals From Electric Utilities; A Holistic Approach to Closure Part A: Deadline To Initiate Closure." . 2020-08-28.EPA (2020-11-12). "Hazardous and Solid Waste Management System: Disposal of CCR; A Holistic Approach to Closure Part B: Alternate Demonstration for Unlined Surface Impoundments." Final rule. A final regulation for inactive surface impoundments was published in 2024.EPA (2024-05-08)."Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals From Electric Utilities; Legacy CCR Surface Impoundments." Final rule.
Water pollution Coal-fired boilers, using either coal or lignite rich in limestone, produces fly ash containing calcium oxide (CaO). CaO readily dissolves in water to form slaked lime (Ca(OH)2) which is carried by rainwater to rivers/irrigation water from the ash dump areas. Lime softening process precipitates Ca and Mg ions / removes temporary hardness in the water and also converts sodium bicarbonates in river water into sodium carbonate. Sodium carbonate (washing soda) further reacts with the remaining Ca and Mg in the water to remove / precipitate the total hardness. Also, water-soluble sodium salts present in the ash enhance the sodium content in water further. Thus river water is converted into soft water by eliminating Ca and Mg ions and enhancing Na ions by coal-fired boilers. Soft water application in irrigation (surface or ground water) converts the fertile soils into alkaline sodic soils.Managing irrigation water quality, Oregon State University, US , Retrieved on 4 October 2012. River water alkalinity and sodicity due to the accumulation of salts in the remaining water after meeting various transpiration and evaporation losses, become acute when many coal-fired boilers and power stations are installed in a river basin. River water sodicity affects downstream cultivated river basins located in China, India, Egypt, Pakistan, west Asia, Australia, western US, etc.
Pollutant discharges from ash ponds to surface waters typically include arsenic, lead, mercury, selenium, chromium, and cadmium. In the US, discharges to surface waters from mine drainage, coal storage facilities, coal preparation plants and ash ponds are regulated by permits in the National Pollutant Discharge Elimination System (NPDES).
Waste management
The burning of coal leaves substantial quantities of fly ash, which is usually stored in ash ponds (wet storage) or landfills (dry storage). Pollutants such as heavy metals leach into groundwater from unlined ponds or landfills, and can pollute aquifers for decades or centuries. The EPA classified 44 sites in the US as potential hazards to communities. Such a classification means that the waste sites could cause death and significant property damage if an event such as a storm, a terrorist attack or a structural failure caused a spill. EPA estimated that about 300 dry landfills and wet storage ponds are used around the country to store ash from coal-fired power plants. The storage facilities hold the noncombustible ingredients of coal, including the ash captured by equipment designed to reduce air pollution.