Mining remains an essential and growing part of the modern industry. By some estimates, itmakes up nearly 45%of the total global economy, and mineral production continues to increase as demand for raw materials grows around the world.
However, many mining techniques still in use can have serious impacts on both the mining site itself and the surrounding environment.
Here aresome general effects of mining on the environment, the impact of different mining methods, and ways in which the industry is trying to make itself more eco-friendly.
The Environmental Impact of Mining
Here’s a quick outline of the various environmental effects of mining, and why mining is bad for the environment.
Air Pollution
Ore dust and gases released by themining process are bad for the health of miners as well as the environment.Over time, exposure to the dust created by mining operations can lead todisease and buildup of scar tissue in the lungs.
Diesel-powered equipment, which naturally creates carbon emissions, furthercontributes to air pollution produced by mining.
Water Pollution
Materials left over by the miningprocess can easily make their way into local water systems, leading toincreased acidity and heavy metal contamination that can destroy wildlife andrender water undrinkable.
Some forms of mining also require thedraining of underground water reservoirs called aquifers, which can causeserious impacts — like drying up springs, cutting off rivers and degradinglocal ecosystems.
Soil Erosion
Pit mining, one of the most commontechniques, hollows out land to extract raw materials. It blasts away land andstrips vegetation, leaving the area vulnerable to soil erosion — the wearingaway of the topsoil layer of time. Topsoil is necessary for plants to grow, andwithout it, mining sites can’t truly recover.
Worse, soil erosion can often spread,meaning that mining can lead to effects on the soil beyond the site.
Habitat Damage
All these different effects add up toserious on-site habitat damage. Mining also creates knock-on effects — likewater pollution, air pollution and vegetation loss as a result of soileruption. This can lead to greater habitat loss beyond the immediate location.
Habitats can be restored after miningoperations are finished, but some impacts will linger. Even in sites that arerehabilitated, biodiversity will typically be lower than it was before.
Different Mining Methods and their Environmental Impact
Different methods of mining have a variety of environmental impacts, ranging from minor to major.
Open-Pit Mining
Open-pit mining, one of the most common forms, is one of the most damaging.Miners hollow out a section of land, digging down to create a workable area and extract valuable raw materials.
This method leaves behind large pits in the earth and can contaminate the groundwater with chemicals used in the mining process.
The land left behind, if not rehabilitated, is typically vulnerable to further soil erosion, further scattering what little topsoil was left over. It’s often not suitable for plant or animal life. Without human intervention, it may take years or decades for the land to become usable again.
Underground Mining
Underground mining, where miners tunnel beneath the Earth’s surface to extract mineral deposits, is rarer than open-pit mining. In 2014, itmade up about 5%of all American mining operations — and has less of an impact on the surface.
However, this doesn’t mean that underground mining doesn’t have an effect on the environment. In fact, its environmental impact is quite large.
With this mining method, rocks and minerals are brought to the surface from tunnels underground. There, toxic chemicals in the waste material can escape into the environment and local waterways if not properly disposed of.
Underground mines can also cause subsidence on the surface — the land above begins to sink, usually when underground supports fail in abandoned or inactive mines. This can shift buildings, destroy infrastructure and harm the surface environment.
Undergroundmining can also sometimes lower the water table. If miners need to dig throughan aquifer or water-laden layer of earth, water will need to be pumped out ofthe mine for work to continue. This dewatering can dry up springs,cut off rivers and degrade local ecosystems.
Somestudies even suggest that while underground mining typically has less of asurface impact than the open-pit variety, it may have a worse effecton the environment overall.
Other Mining Methods
Somemining techniques—like in-situ leaching, which uses acid and waterto remove minerals from a site without significantly disturbing the surface —have much less environmental impact. In-situ mining techniques can use lesswater than open-pit mining and underground mining, and also reduce the risk ofreleasing ore dust into the atmosphere.
However,even low-impact mining techniques like in-situ mining aren’t consequence-free.The strong acids used to break down ore and rocks can result in acidification of the surrounding environment. The acids can alsodissolve the metal and radioactive isotopes in these ores during the leachingprocess, both of which can find their way into nearby water sources.
The Lasting Impacts of Mining
Partof what makes the environmental impact of mining so severe is how long theirside-effects can last after the initial mining operations have ended.
Forexample, disturbed soil will often continue to erode away for a long time intothe future, especially if leftover waste or a scattered topsoil layer preventsnew vegetation from growing.
Oreresidue and acid leach heaps left by mining processes can also erode rock andeventually pollute waterways. At the Holden Mine Superfund Site, for example, more than 100 million metric tons of leftover materials are currently at risk of leachinginto the Columbia River.
Thecompany that owns the mine invested in a remediation wall to prevent thesetoxic waste materials from leaching into the river, but the wall isn’t apermanent solution. Severe flooding could easily wash the waste elements intowaterways, meaning the site will likely require further rehabilitation.
Plasticand rubber left by equipment like earth-mover tires will stick around if notdirectly addressed. This can pose other problems, too — like the air pollutioncreated as a result of diesel-burning engines.
Thesenegative environmental effects can continue long after a mining company hasstopped operations, packed up its equipment and moved on.
What’smore, even though rehabilitation can prevent the effects of mining from gettingworse over time, not all companies invest in rehabilitating their sites. As aresult, many are left alone to pollute the nearby environment for years or evendecades to come.
Possible Green Future of Mining
Companiesmay move in the direction of sustainability — especially as pressure fromindividuals and governments push them to comply with higher standardsofenvironmental and social governance (ESG). Expert leaders on ESGand industry professionals from within miningpredict operations will begin to think moreseriously about sustainability.
Forexample, some mining companies are experimenting with advanced landrehabilitation schemes that can help reintroduce plant life to formersites.
Withthe use of biosolids —nutrient-rich organics derived from sewagetreatment processes that are often used as soil conditioners in agriculture —it may be possible to reintroduce plant life to former mining sites in as few as 12weeks.
Other,even more ambitious rehabilitation plans are focused on the best possiblestewardship of former mining sites. These plans look to not only rehabilitatethe land, but also aim to reintroduce 100%of the species that were living there before operationsbegan.
Equipmentupgrades could also reduce the impact mining has on the environment.
Machineswith electric engines are becoming increasingly popular, with some companies,like Swedish mining equipment manufacturer Epiroc, even going so far as topledge using100% electric products over the next few years. Widespread adoption of electric enginescould easily help the industry reduce the amount of carbon dioxide it naturallyproduces.
Low-impactmining techniques are also becoming more popular. In-situ mining is seeingbigger use in countries like China, which is trying to grapple withgrowing mineraldemand,the size of the mining industry and the significant impact on theenvironment.
Socialchanges from outside the industry may also naturally reduce mining’s carbon footprintover time and encourage more environmentally friendly techniques. For example,as businessesturn away from nonrenewable resources, mining may naturally follow suit.
Conclusion
Miningcontinues to be a huge component of the global economy — and in the future,it’s likely to only grow larger as the demand for raw materials increases.
Thisis troubling for those who care about the environment. Mining can often bedevastating — causing water acidification, soil erosion and the degradation oflocal ecosystems. While some methods have less impact than others, it almostalways has a serious and lasting environmental impact.
Fortunately, there is some hope that mining will become more sustainable in the future. The adoption of low-impact techniques and more eco-friendly equipment — plus pressure from environmentally minded individuals and governments — may make the industry more eco-friendly over time.
About the Author: Jenna Tsui
Jenna is a tech journalist who co-ownsThe Byte Beatand frequently writes about the latest news in technology, disruptive tech, and environmental science and more. Check out her work on TBB or follow her on Twitter@jenna_tsui!
