User:Taylorbenda/EnviroImpactofMin

Introduction
Environmental impacts of mining can occur at local, regional, and global scales through direct and indirect mining practices. Impacts 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 have an impact on the atmosphere from the emissions of carbon which have 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.

Erosion
Erosion of exposed hillsides, mine dumps, tailings dams and resultant siltation of drainages, creeks and rivers can significantly impact the surrounding areas, a prime example being the giant Ok Tedi Mine in Papua New Guinea. In wilderness areas mining may cause destruction and disturbance of ecosystems and habitats, and in areas of farming it may disturb or destroy productive grazing and croplands.

Sinkholes
A sinkhole at or near a mine site is typically caused from the failure of a mine roof from the extraction of resources, weak overburden or geological discontinuities. The overburden at the mine site can develop cavities in the subsoil or rock, which can be infilled by sand and soil from the overlying strata. These cavities in the overburden will eventually cave in and a sinkhole will appear at the surface. The sudden failure of Earth creates a large depression at the surface without warning, this can be seriously hazardous to life and property. Sinkholes at a mine site can be mitigated with the proper design of infrastructure such as mining supports and better construction of walls to create a barrier around an area prone to sinkholes. Back-filling and grouting can be done to stabilize abandoned underground workings.

Water Pollution
Mining can have harmful effects on surrounding surface and groundwater. If proper precautions are not taken, unnaturally high concentrations of chemicals, such as arsenic, sulfuric acid, and mercury over a significant area of surface or subsurface water. With large amounts of water used for mine drainage, mine cooling, aqueous extraction and other mining processes, increases the potential for these chemicals to contaminate ground and surface water. As mining produces copious amounts of waste water, disposal methods are limited do to contaminates within the waste water. Runoff containing these chemicals can lead to the devastation of the surrounding vegetation. The dumping of the runoff in surface waters or in a lot of forests is the worst option. Therefore, submarine tailings disposal are regarded as a better option (if the waste is pumped to great depth). Land storage and refilling of the mine after it has been depleted is even better, if no forests need to be cleared for the storage of debris. The contamination of watersheds resulting from the leakage of chemicals also has affect on the health of the local population.

In well-regulated mines, hydrologists and geologists take careful measurements of water to take precaution to exclude any type of water contamination that could be caused by the mine's operations. The minimization of environmental degradation is enforced in America mining practices by federal and state law, by restricting operators to meet standards for the protection of surface and groundwater from contamination. This is best done through the use of non-toxic extraction processes as bioleaching.

Tailings
Mining processes produce an excess of waste materials known as tailings. The materials that are left over after are a result of separating the valuable fraction from the uneconomic fraction of ore. These large amounts of waste are a mixture of water, sand, clay, and residual bitumen. Tailings are commonly stored in tailings ponds made from naturally existing valleys or large engineered dams and dyke systems. Tailings ponds can remain part of an active mine operation for 30-40 years. This allows for tailings deposits to settle, or for storage and water recycling.

Tailings have great potential to damage the environment by releasing toxic metals by acid mine drainage or by damaging aquatic wildlife, these both require constant monitoring and treatment of water passing through the dam. However the greatest danger of tailings ponds is dam failure. Tailings ponds are typically formed by locally derived fills (soil, coarse waste, or overburden from mining operations and tailings) and the dam walls are often built up on to sustain greater amounts of tailings. The lack of regulation for design criteria of the tailings ponds are what put the environment at risk for flooding from the tailings ponds.

Spoil Tip
A spoil tip is a pile of accumulated overburden that was removed from a mine site during the extraction of coal or ore. These waste materials are composed of ordinary soil and rocks, with the potential to be contaminated with chemical waster. Spoil is much different from tailings, as it is processed material that remains after the valuable components have been extracted from ore. Spoil tip combustion can happen fairly commonly as, older spoil tips tend to be loose and tip over the edge of a pile. As spoil is mainly composed of carbonaceous material that is highly combustible, it can be accidentally ignited by the lighting fire or the tipping of hot ashes. Spoil tips can often catch fire and be left burning underground or within the spoil piles for many years.

Need to rewrite paragraph.

Air Pollution
Air pollution from coal mines are typically caused from emissions of particulate matter and gases including methane (CH4), sulfur dioxide (SO2), and oxides of nitrogen (NOx), as well as carbon monoxide (CO). Open-pit mining is one of the lead methods of production for coal mining. However this method is a major contributor to air pollution. The dust particles emitted from the mining process act as a catalysis in the air allowing for chemical reactions to take place. An extreme example that is a source of air pollution are coal fires caused by left over coal.

Mines have begun to implement preventative and suppression measures such as dust extraction systems. Natural pollution control is one of the best measures for controlling air pollution, this can be done through the plantation of trees surrounding the impacted area.

Other methods of mining (do or dont) contribute to air pollution. If so how or how not.

Sustainable mining
https://www-sciencedirect-com.proxy.library.carleton.ca/science/article/pii/S2212827117301956

https://www-sciencedirect-com.proxy.library.carleton.ca/science/article/pii/S0964830517313707

Sources

https://www-sciencedirect-com.proxy.library.carleton.ca/science/article/pii/S0964830517313707

https://ebookcentral-proquest-com.proxy.library.carleton.ca/lib/oculcarleton-ebooks/reader.action?docID=1185748

https://www.sciencedirect.com/science/article/pii/S0375674208000861

https://miningwatch.ca/sites/default/files/01.STDtoolkit.intr_.pdf