The extraction of natural resources is responsible for lasting interventions in nature and the landscape in Germany, e. g. because overburden has to be removed and heaped up in piles or areas are temporarily used to erect conveyors or other operating plant. (1) The statutory requirements of the Federal Mining Act guarantee that rehabilitation will be planned at an early stage and taken into account. A balance is achieved between the interests of the extractive sector and the environment in the approval procedure reflecting the Federal State’s plans and mining law. Citizens, the elected political representatives of mining regions together with sectoral authorities, environmental associations and other public interest parties have various opportunities to exercise influence and be involved in co-determination. In general, the principle that the burden on the environment must be kept to the minimum applies to both the planning and operation of mines. In addition to this, the mining operator has an obligation to rehabilitate the areas affected by the extraction of natural resources (§ 55 BBergG). The measures on how the surface will be structured in an individual case is part of the planning and approval process and depends on the original condition of the area used for mining and what the plans are for its future use.
When the mining authorities approve the respective operating plans, one of the aspects they also check is whether the company can finance the costs that will be incurred at the time as a result of future rehabilitation obligations. If there are any doubts, the mining authorities can make approval of an operating plan dependent on implementation securities (§ 56(2) 2 BBergG).
As a rule, the companies make provisions to meet their future mining-related obligations. The purpose of these provisions is to provide financial security for the rehabilitation and the amount must be assessed accordingly. The principles of provisions are the rules on setting up provisions for future obligations that are binding for all businesses under commercial law.
Where rehabilitation is carried out during extraction and processing operations, the areas taken for extraction are generally rehabilitated in parallel to the continuing extraction. In the course of extracting natural resources, the material on the site is piled up and the shape of the land changed whilst adhering to safety requirements. The land is rehabilitated by means of geotechnical, landscaping, hydraulic engineering, agricultural and forestry measures to restore the land usage or biotopes.
One example of this is groundwater lowering required for operation in opencast mines. In these cases, backfilled areas must be designed in such a way that no unwanted waterlogging occurs preventing the intended public interest use (including agriculture, forestry or construction). In addition, the final slopes of opencast mines that are not backfilled and in which a lake is to be created after the end of coal extraction must be laid out and designed in such a way that permanent stability is ensured during and after the rise of groundwater and the filling of the former opencast mine with water. To this end, appropriate technical guidelines are applied and expert assessments are used.
A prerequisite for successful reclamation of minesites is the targeted, selective extraction of soil and the refilling of mining holes using soil material that meets the requirements relevant for the intended subsequent use of the minesite. This requires a correctly coordinated management of soil material. In slope areas, for example, this soil material must primarily fulfil the requirements relevant for ensuring stability. If, for example, a subsequent agricultural use of backfilled areas is planned, the primary reclamation and thus recultivation objective is to restore soil fertility and soil functions as a habitat for plants and cultivation.
The objectives of reclamation and the measures to be taken and requirements to be met for this purpose are defined in lignite plans or the operating plans approved under mining law. Depending on the type of use, the topsoil used for restoration must be “cultivated” and the areas must be gradually looked after and developed.
- Agricultural rehabilitation includes scientifically tested crop rotation with which the rehabilitation of the soil can be achieved. Once successful rehabilitation is complete, the areas are made available for their subsequent use and released from supervision by the mining inspection authorities.
- Rehabilitation through forestry aims to establish mixed woodland with a variety of uses. Depending on site conditions, native species of trees dominate an effective mix of broad-leaved trees and conifers.
Elements to benefit nature are incorporated to support integrated and widespread nature conservation, e. g. planting native trees, including dead wood and other small structures, hedge planting, planting solitary trees, including wild fruit, creating dry biotopes and wet scrapes, retention of small unplanned areas and small areas of succession sites. This work is undertaken according to locally recognised methods and in close cooperation with the specialist nature conservation authorities. It will still be necessary to dewater the surface, build paths and contour the surface for optimum site restoration in order to facilitate functional use after extraction has finished.
Once the natural resources have been extracted, renaturation will be undertaken in accordance with the specification in the final operating plan. In the large majority of cases, a remaining lake exists at the end once opencast lignite mining has finished. The needs of future use after mining will be taken into account in the completion work, providing it has been agreed with future users before the mine was authorised. Underground coal mining has finally ceased in Germany since the end of 2018. After the cessation of hard coal extraction, a targeted withdrawal from the operating buildings takes place. Mechanical equipment, operating materials, pipelines and other operating equipment have to be dismantled and removed from the minesite. In addition, the isolation of mine fields and the backfilling of extraction holes may be necessary. Besides, waste must be disposed of properly. As a rule, the withdrawal from an underground minesite is followed by a rise in mine water. The mine water level must often be limited by removing excess water to avoid any risk to aquifers used to extract drinking water. This usually requires conversion work in mining shafts to be able to resume mine water extraction in due course to limit the rise in mine water.
Land used up for mining activities above ground shall also be properly reclaimed with due regard to the public interest. Here, too, operational facilities and equipment must be dismantled, provided that no other subsequent use is envisaged for them. If the result of a risk assessment indicates a need for remediation, any necessary remediation or safeguarding measures are planned and then implemented. Waste rock piles must also be made usable again so that they do no longer pose a danger even after filling of further material has stopped to enable a duly planned subsequent use.
Any temporary storage or outside heaps created during mining operations are removed or recultivated. Once checks have been carried out to ensure that the soil is safe, waste that had accumulated in heaps since the start of mining is recultivated to form features such as landmarks and also to meet regional planning criteria.
Potash and salts are natural resources mined in underground mines at depths of up to 1,500 metres. In contrast to above-ground extraction of natural resources in opencast mining, apart from the areas required for processing plant the mining of potash and salts does not take up large areas of the surface that would then require extensive rehabilitation of the surface used. For areas used for heaps of residues in potash mining, compensatory and substitution measures are implemented (e. g. reforestation, species protection measures). The heaps are established, operated and shut down (including possible rehabilitation) in line with the relevant requirements under mining and environmental law and taking the relevant site conditions into account.
Once the drilling phase that lasts between two and five months depending on the depth has been completed, the operating site is reduced in size. As only the borehole seal and a few items of plant to separate, collect and transport the extracted crude oil/natural gas remain there, the production equipment is barely visible or audible any more during the entire period of usage.
The deposit is depleted after 20 to 30 years on average. The plant is then removed, and the whole borehole filled up and sealed. The production and processing plant as well as the operating site including the seal are completely removed and the area used recultivated. Aquifers therefore remain protected in the long term and the area can be used again. (2)
Quarrying can be authorised both under mining law and outside mining law (as described here (Approval of mining projects). The regulations in the Federal Immission Control Act (BImSchG), Water Resources Act (WHG) and the Federal Nature Conservation Act (BNatSchG) are important for the extraction of natural resources which, as what are termed free-to-mine and privately-owned natural resources, do not come under mining law as defined by § 3 BBergG..
The provisions of these laws guarantee that the impact of the mining will be balanced out (see Managing human intervention in nature and landscape). This means the operating licence is granted on the basis of planning and rehabilitation considerations or, expressed in other terms, authorisation to operate will not be granted unless provision has been made for the needs of nature conservation. A balance is achieved in the approval process between the interests of the extractive sector and the environment, both in respect of regional planning criteria and also the plant. The groups that are to be consulted (citizens, elected representatives, sectoral authorities, environ- mental associations and chambers) are given various options to participate.
In general, the principle that the burden on the environment must be kept to the minimum and both land and soil must be carefully conserved applies to both the planning and the operation of plants that require a licence. In addition to this the plant operator has an obligation to compensate for significant unavoidable impacts to nature and the environment through compensatory and substitution measures. In addition to the condition of the surfaces, the measures to take for shaping the surface in an individual case and also during the extraction phase depend on the future use of the site.
The companies in the sector temporarily intervene in nature and the landscape because of economic imperatives. A wide variety of habitats is already created during the active extraction phase, which we hardly ever find in our cultural landscape. Even after the end of extraction, these former extraction sites can still represent important refuges for rare animals and plants. Valuable biotopes may develop here after a short time.
For this reason, nature conservation concerns often dominate the subsequent use of quarrying areas. In general, the areas on which natural resources were extracted are upgraded through recultivation and renaturation and returned to society.
The companies encourage biodiversity as a result of cooperation with nature conservationists and targeted management measures. In 2004, the building materials industry affirmed its commitment at national level with a declaration together with the German Nature and Biodiversity Conservation Union (NABU), the industrial trade union for construction, agriculture and environment (IG BAU) and the industrial trade union for mining, chemicals and the energy trade (IG BCE). In addition to this, companies in the quarried natural resources industry are involved in the “Biodiversity in Good Company” corporate network; the German Building Materials Association – Quarried natural resources (bbs) is involved as the sector’s umbrella organisation in the corresponding “Enterprise biological diversity” association network.
The bbs, in cooperation with its members in the extractive sector, are establishing a nationwide biodiversity database to document the contributions that the quarried natural resources sector is making to protect and conserve biodiversity.
(1) See Managing human intervention in nature and landscape for more information on how nature is affected by extracting natural resources.
(2) Bundesverband Erdgas, Erdöl und Geoenergie e.V. (German association for natural gas, petroleum and geothermal energy) (2021): Removal and recultivation of operating sites. URL: https://www.bveg.de/Erdgas/Umwelt-und-Sicherheit/Rueckbau-und-Rekultivierung [Accessed on 9 December 2022].