Land rehabilitation

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Recently constructed wetland regeneration in Australia, on a site previously used for agriculture. Wetland restoration in Australia.jpg
Recently constructed wetland regeneration in Australia, on a site previously used for agriculture.
Regenerated habitat for the superb parrot on the abandoned Boorowa railway line Regenerated habitat for superb parrot on the abandoned Boorowa railway line.jpg
Regenerated habitat for the superb parrot on the abandoned Boorowa railway line

Land rehabilitation as a part of environmental remediation is the process of returning the land in a given area to some degree of its former state, after some process (industry, natural disasters, etc.) has resulted in its damage. Many projects and developments will result in the land becoming degraded, for example mining, farming and forestry.

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Mine rehabilitation

Modern mine rehabilitation aims to minimize and mitigate the environmental effects of modern mining, which may in the case of open pit mining involve movement of significant volumes of rock. Rehabilitation management is an ongoing process, often resulting in open pit mines being backfilled.

After mining finishes, the mine area must undergo rehabilitation.

For underground mines, rehabilitation is not always a significant problem or cost. This is because of the higher grade of the ore and lower volumes of waste rock and tailings. In some situations, stopes are backfilled with concrete slurry using waste, so that minimal waste is left at surface.

The removal of plant and infrastructure is not always part of a rehabilitation programme, as many old mine plants have cultural heritage and cultural value. Often in gold mines, rehabilitation is performed by scavenger operations which treat the soil within the plant area for spilled gold using modified placer mining gravity collection plants.

Also possible is that the section of the mine that is below ground, is kept and used to provide heating, water and/or methane. Heat extraction can be done using heat exchangers, that convey the heat to a nearby city (hence making it be used for district heating purposes. [1] Water can be harvested from the mine as well (mines are often filled with water once the mine has been shut down and the pumps no longer operate). Methane is also often present in the mine shafts, in small quantities (often around 0,1%). This can still be recovered though with specialised systems. [2] [3] [4] An added advantage of recovering the methane finally is that the methane does not come into the atmosphere, and so does not contribute to global warming.

Mine rehabilitation market

Depending on the country, mining companies are regulated by federal and state bodies to rehabilitate the affected land and to restore biodiversity offset areas around the mines. [5] [6]

Mine rehabilitation, a legal obligation for mining companies in Australia for which they are required to pay bonds, could be a source of considerable employment generation and economic investment in regional areas, if governments were willing to enforce the laws covering the process. [7] [8] [9] [10]

Before mining activities begin, a rehabilitation security bond must be provided. [11] The Australian mine rehabilitation bonds totals $9.49bn, with the state of NSW bond totalling $2.68 billion in 2019. The size of mining security bonds has been questioned by NSW's Auditor General [12] as being insufficient to cover the complete costs associated with mine rehabilitation activities.

In addition to operational mine rehabilitation activities, often referred to as 'progressive rehabilitation', abandoned mines are also restored. The financing for restoration of abandoned mines is drawn from operating mines as well as public sources. The cost of reclaiming the abandoned mines in the US is estimated at $9.6bn.

See also

Related Research Articles

Environmental geology, like hydrogeology, is an applied science concerned with the practical application of the principles of geology in the solving of environmental problems created by man. It is a multidisciplinary field that is closely related to engineering geology and, to a lesser extent, to environmental geography. Each of these fields involves the study of the interaction of humans with the geologic environment, including the biosphere, the lithosphere, the hydrosphere, and to some extent the atmosphere. In other words, environmental geology is the application of geological information to solve conflicts, minimizing possible adverse environmental degradation, or maximizing possible advantageous conditions resulting from the use of natural and modified environment. With an increasing world population and industrialization, the natural environment and resources are under high strain which puts them at the forefront of world issues. Environmental geology is on the rise with these issues as solutions are found by utilizing it.

<span class="mw-page-title-main">Open-pit mining</span> Surface mining technique

Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow.

<span class="mw-page-title-main">Tailings</span> Materials left over from the separation of valuable minerals from ore

In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed.

<span class="mw-page-title-main">Coalbed methane</span> Form of natural gas extracted from coal beds

Coalbed methane, coalbed gas, or coal seam gas (CSG) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Australia, and other countries.

<span class="mw-page-title-main">Mine reclamation</span> Process of restoring land that has been mined to a natural or usable state

Mine reclamation is the process of modifying land that has been mined to ecologically functional or economically usable state. Although the process of mine reclamation occurs once mining is completed, the planning of mine reclamation activities occurs prior to a mine being permitted or started. Mine reclamation creates useful landscapes that meet a variety of goals ranging from the restoration of productive ecosystems to the creation of industrial and municipal resources. In the United States, mine reclamation is a regular part of modern mining practices. Modern mine reclamation reduces the environmental effects of mining.

<span class="mw-page-title-main">Longwall mining</span> Form of underground coal mining

Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice. The section of rock that is being mined, known as the longwall panel, is typically 3–4 km (1.9–2.5 mi) long, but can be up to 7.5 km (4.7 mi) long and 250–400 m (820–1,310 ft) wide.

<span class="mw-page-title-main">Surface mining</span> Type of mining in which the soil/rock above mineral deposits is removed

Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit are removed, in contrast to underground mining, in which the overlying rock is left in place, and the mineral is removed through shafts or tunnels.

The Colomac Mine was a privately owned and operated open pit gold mine located 200 km northwest of Yellowknife in the Northwest Territories in Canada. The Colomac mine operated between 1990–1992, and 1994–1997. It was operated by Neptune Resources Limited that had little success in making a profit during its operation. In 1994, the mine had reopened under Royal Oak Mines Inc. Both Neptune Resources and Royal Oak Mines where both owned and operated by Peggy Witte. Due to low gold prices and high cost of mining, Royal Oak Mines was forced into bankruptcy. The Federal Government of Canada became owners of the mine, along with the related environmental issues. A major cleanup effort was completed to prevent the mine from polluting the environment. On January 26, 2012, Nighthawk Gold Corporation completed an agreement to acquire 100% of the mineral claims and leases of the former producing Colomac Gold Mine and surrounding mineral leases, from then Aboriginal Affairs and Northern Development Canada (AANDC) now Crown Indigenous Relations and Northern Affairs Canada (CIRNAC). The Colomac Property lies within the central portion of Nighthawk Gold’s 930 square kilometre property. Nighthawk Gold has since been responsibly exploring and advancing the Colomac Gold Project with the goal to restart gold mining operations in the future, assuming positive economics and the receipt of operating permits.

<span class="mw-page-title-main">Sulphur Bank Mine</span>

The Sulphur Bank Mine is located near Clearlake Oaks and Clear Lake in Lake County, California. The 150-acre (0.61 km2) mine became one of the most noted mercury producers in the world.

<span class="mw-page-title-main">Health and environmental impact of the coal industry</span>

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.

<span class="mw-page-title-main">Environmental effects of mining</span> Environmental problems from uncontrolled mining

Environmental effects of mining can occur at local, regional, and global scales through direct and indirect mining practices. Mining can cause in erosion, sinkholes, loss of biodiversity, or the contamination of soil, groundwater, and surface water by chemicals emitted from mining processes. These processes also affect the atmosphere through carbon emissions which contributes to climate change. 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.

<span class="mw-page-title-main">Land restoration</span> Reinstatement of damaged landscape

Land restoration, which may include renaturalisation or rewilding, is the process of ecological restoration of a site to a natural landscape and habitat, safe for humans, wildlife, and plant communities. Ecological destruction, to which land restoration serves as an antidote, is usually the consequence of pollution, deforestation, salination or natural disasters. Land restoration is not the same as land reclamation, where existing ecosystems are altered or destroyed to give way for cultivation or construction. Land restoration can enhance the supply of valuable ecosystem services that benefit people.

The Del Amo Superfund Site is located in southern Los Angeles County between the cities of Torrance and Carson. It is a U.S. EPA Region 9 Superfund Site. The waste-disposal site of a rubber manufacturer is one of 94 Superfund Sites in California as of November 29, 2010.

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.

<span class="mw-page-title-main">Mount Polley mine</span> Gold and copper mine in British Columbia, Canada

The Mount Polley mine is a Canadian gold and copper mine located in British Columbia near the towns of Williams Lake, and Likely. It consists of two open-pit sites with an underground mining component and is owned and operated by the Mount Polley Mining Corporation, a wholly owned subsidiary of Imperial Metals. In 2013, the mine produced an output of 38,501,165 pounds (17,463,835 kg) of copper, 45,823 ounces of gold, and 123,999 of silver. The mill commenced operations in 1997 and was closed and placed on care and maintenance in 2019. The company owns 20,113 hectares (201.13 km2) of property near Quesnel Lake and Polley Lake where it has mining leases and operations on 2,007 hectares (20.07 km2) and mineral claims on 18,106 hectares (181.06 km2). Mineral concentrate is delivered by truck to the Port of Vancouver.

Water in Arkansas is an important issue encompassing the conservation, protection, management, distribution and use of the water resource in the state. Arkansas contains a mixture of groundwater and surface water, with a variety of state and federal agencies responsible for the regulation of the water resource. In accordance with agency rules, state, and federal law, the state's water treatment facilities utilize engineering, chemistry, science and technology to treat raw water from the environment to potable water standards and distribute it through water mains to homes, farms, business and industrial customers. Following use, wastewater is collected in collection and conveyance systems, decentralized sewer systems or septic tanks and treated in accordance with regulations at publicly owned treatment works (POTWs) before being discharged to the environment.

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.

Waste valorization, beneficial reuse, beneficial use, value recovery or waste reclamation is the process of waste products or residues from an economic process being valorized, by reuse or recycling in order to create economically useful materials. The term comes from practices in sustainable manufacturing and economics, industrial ecology and waste management. The term is usually applied in industrial processes where residue from creating or processing one good is used as a raw material or energy feedstock for another industrial process. Industrial wastes in particular are good candidates for valorization because they tend to be more consistent and predictable than other waste, such as household waste.

<span class="mw-page-title-main">Legacy pollution</span> Pollution caused by historical use of a chemical

Legacy pollution or legacy pollutants are persistent materials in the environment that were created through a polluting industry or process that have polluting effects after the process has finished. Frequently these include persistent organic pollutants, heavy metals or other chemicals residual in the environment long after the industrial or extraction processes that produced them. Often these are chemicals produced by industry and polluted before there was widespread awareness of the toxic effects of the pollutants, and subsequently regulated or banned. Notable legacy pollutants include mercury, PCBs, Dioxins and other chemicals that are widespread health and environmental effects. Sites for legacy pollutants include mining sites, industrial parks, waterways contaminated by industry, and other dump sites.

References

  1. MijnWater BV recovering heat from abandoned mines
  2. The West Cliff Collier Power Plant has successfully been able to recover methane from ventilation shafts of mines
  3. Ventilation Air Methane
  4. The Blue Economy By Gunter Pauli
  5. https://nma.org/wp-content/uploads/2016/08/Federal-Environmental-Laws-that-Govern-US-Mining-2018.pdf [ bare URL PDF ]
  6. https://www.industry.gov.au/sites/default/files/2019-04/lpsdp-mine-rehabilitation-handbook-english.pdf [ bare URL PDF ]
  7. "Mind the Gap: how fixing mine rehabilitation shortfalls could fuel jobs growth in the Hunter Valley". Lock the Gate Alliance. 2018. Archived from the original on 2023-06-04. Retrieved 2022-12-14.
  8. "Creating up to 5,000 job is Central Queensland by eliminating the coal mine rehabilitation deficit". Lock the Gate Alliance. 2018. Archived from the original on 2023-06-04. Retrieved 2022-12-14.
  9. "Mine rehabilitation and closure cost : a hidden business risk". Lock the Gate Alliance. 2016. Archived from the original on 2023-06-08. Retrieved 2022-12-14.
  10. "Abandoned mines In Queensland : toxic time-bomb or employment opportunity?". Lock the Gate Alliance. 2016. Archived from the original on 2023-06-06. Retrieved 2022-12-21.
  11. "Rehabilitation | NSW Resources Regulator".
  12. "New South Wales Auditor-General's Report: Performance Audit" (PDF). audit.nsw.gov.au. Department of Planning and Environment.