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close this bookEnvironmental Handbook Volume II: Agriculture, Mining/Energy, Trade/Industry (GTZ, 1995, 736 p.)
close this folderMining and energy
close this folder37. Underground mining
View the document1. Scope
View the document2. Environmental impacts and protective measures
View the document3. Notes on the analysis and evaluation of environmental impacts
View the document4. Interaction with other sectors
View the document5. Summary assessment of environmental relevance
View the document6. References

1. Scope

Mining is defined as the extraction of mineral resources from the earth. Underground mining is the extraction of raw materials below the earth's surface (deep mining) and their conveyance to the surface. Access to the vein or lode is by shafts and tunnels with links to the surface. (The subsequent stages of raw material processing are dealt with in a separate brief: Minerals - Handling and Processing.) The present brief examines only the underground extraction of solid mineral resources.

There are some 70 individual types of useful minerals that occur in minable concentrations either alone or in combination with other minerals, frequently as natural mixtures (aggregates).

Underground mining includes all work involved in the winning of raw materials by people using technical contrivances. Apart from the actual extraction and conveyance processes, the term underground mining also covers development of the deposit and provision of the requisite infrastructure (transportation/handling, storage facilities, surface plant, e.g., administration building, workshops, etc.) and all measures devoted to ensuring the safety of the miners. This includes:

working

conveyance

ventilation

loading

drainage

support

Small-scale mining activities in many countries frequently include a transitional form of extraction referred to as trench mining, or burrowing.

In special cases, the mineral can be made transportable and hauled off from its natural surroundings with no need of exploratory work (brine mining, in-situ leaching and in-situ gasification of coal).

Deep mining creates underground spaces in which people work. Their working conditions with regard to air temperature and humidity, presence of harmful or explosive gases or radiation, as well as moisture, dust and noise, can be specific to the mined mineral and/or the surrounding rock, the depth of the mine, and the type of machinery in use.

The locations of deep mines are dictated by the presence of potentially profitable raw materials. Underground extraction is practiced in all climate zones, in remote areas as well as under large cities, on the ocean floor and in alpine regions. The size, or output, of such mines ranges from less than 1 to more than 15 000 tons a day, and the depth at which extraction takes place ranges from a few meters to more than 4 kilometers.

2. Environmental impacts and protective measures

Deep mining impacts the environment in three different areas: in the deposit itself and the surrounding rock, in the underground spaces created by and for the mine, and aboveground. Optimal exploitation of the resource with attendant limitation of environmental effects is dependent on detailed planning of the sequence of operations and on the mining methods and technology to be employed.

2.1 Environmental impacts on the deposit and the surrounding rock

2.1.1 Exploitation of resources

The most important environmental consequence of underground mining is that it involves the exploitation of a nonrenewable resource. The process of extracting the raw material necessarily also involves mining losses and impairment of other parts of the deposit. The best way to counter the latter effects is to carefully plan the extraction operations, stowing measures, etc.

Some raw materials (coal and several sulfidic ores) can under certain circumstances ignite spontaneously and cause mine fires.

2.1.2 Disruption of rock structure

The opening up of underground workings creates cavities and leads to stress and motion in the surrounding rocks. The effects of mining on the rock structure can include:

- subsidence due to cave-ins in the cavities. The resultant settling can propagate to the surface, possibly causing damage to structures and facilities (subsidence damage; cf. section 2.3.3 for protective measures);
- destruction of hanging parts of the deposit (most likely as a result of inadequate extraction planning).

2.1.3 Disruption of groundwater flow

The opening up of underground workings modifies the formerly stable water balance of the rock structure by creating new water conduits. Water drainage, for example, can cause significant recession of the groundwater level with substantial attendant detriment to vegetation within the affected area (cf. section 2.3.2).

2.1.4 Alteration of groundwater quality

Mining activities can pollute groundwater in several ways: mine waters (cf. item 2.2.4), for example, can enter the groundwater system, and various alkaline and other solutions used in in-situ dressing processes, as well as leakage losses of refrigerants used in the sinking of shafts, all can contaminate the groundwater, just as the leaching of dumps produces percolating water that can alter the character of groundwater. Effective preventive measures include the sealing off of soils, shafts and worked-out parts of the deposit, drainage and/or canalization.

2.2 Underground environmental impacts

Man, machine, rock and climate all interact underground, whereas man is impacted most significantly. Matters concerning the health and safety of miners are therefore given priority consideration.

2.2.1 Air / climate

The underground climate is influenced by the elevated temperature of deep rock and by the gases and liquids it contains.

Table 1 - Factors influencing the atmosphere in underground mines

Potential hazard /

caused by...

danger of...

Preventive measures

Reference values

Oxygen deficiency (O2) --------- 19 % min.

displacement by irrespirable (black) damps and firedamps, respiration, open mining lamps, mine fires

fatigue, asphyxia

ventilation

Radiation

radioactive rock compo-nents, measuring probes

radiation affection

limited exposure time with dosimetric control

Radon

gas evolution from surrounding rock

radiation affection

ventilation, limited exposure time

Methane (CH4) --------- 5 - 14 % = explosive

gas evolution from coal

explosion

gas extraction, ventilation, flameproof equipment

Coal dust

mining, handling of coal

explosion

dust precipitation, flameproofing

Carbon monoxide (CO) --------- > 50 ppm

exhaust, gas evolution in abandoned hard-coal mines

poisoning

ventilation

Carbon dioxide (CO2) --------- > 1 %

gas eruption in salt, exhaust, gas evolution from thermal waters

asphyxia

ventilation

Hydrogen sulfide (H2S) --------- > 20 ppm

gas evolution from mine and thermal waters

poisoning

ventilation

Oxydes of nitrogen (NOx) and blast damp

blasting

poisoning

ventilation, specification of blasting times

Exhaust gases

engine exhaust

poisoning

ventilation

Low-temperature carboni-zation gases, smoke

mine fires

poisoning

extinguishment, damming off, precautionary measures

Aerosols of oil

pneumatic equipment

poisoning

oil precipitation

Heat

elevated rock temperatures, off-heat from engines

fatigue

ventilation, air cooling

2.2.2 Noise

In underground workings, noise is generated by drilling and blasting, by internal-combustion engines and pneumatic and hydraulic motors, and by various means of conveyance (conveyor belts, trains, vehicles) and fans.

Machine-generated noise can be reduced by various design measures, and ear protectors are mandatory beginning at certain sound intensity levels.

2.2.3 Dust

Exposure to dust (stone dust in coal mines, for example) must be limited to minimize the incidence of related diseases, the most dangerous of which is silicosis resulting from the inhalation of silica particles. Dust forms when rock is destroyed by mechanical means (drilling, blasting, crushing, handling, etc.).

Dust consisting of the following mineral substances poses a hazard to human health: asbestos, beryllium, fluorspar, nickel ores, quartz, mercury, cinnabar, titanium dioxide, manganese oxide, uranium compounds and tin ores. Pulverized asbestos and respirable dust containing nickel ore and/or beryllium, as well as soot from diesel engines, are carcinogenic. Coal dust can cause dust explosions.

Countermeasures against dust pollution include its consolidation during drilling and conveying, either by spraying it with water or by saturating the face through appropriately arranged boreholes prior to extraction. Gas masks prevent the inhalation of dust, and filters on engines bond soot particles.

2.2.4 Mine waters

Mining activities alter the characteristics of mine waters.

Appropriate safety clothing protects miners against aggressive mine waters, and appropriately resistant materials prevent corrosion of material goods.

Table 2 - Pollution of mine and surface waters

Type of pollution

Typical polluting substances

Preventive Measures

Altered pH

neutralization

Soluble inorganic substances

heavy metals, salts, sulfur

precipitation

Insoluble inorganic suspended solids

mud

agglomeration and settling

Organic substances

oil, grease, lubricants, emulsifying agents

precipitation in settling tanks

Heat

cooling, mixing

2.3 Aboveground environmental impacts

The aboveground environmental consequences derive from communication between the mine and the surface in the form of ventilation, mine pumping and conveyance of the product, in combination with establishment of the requisite aboveground mining infrastructure. Vibrations caused by blasting and ground movement are also perceptible aboveground.

2.3.1 Air / climate

The harmful effects of air pollution, particularly on nearby vegetation can be alleviated by filtering the outgoing air from the shafts and tunnel faces. Dumping and wind-induced erosion of dumps can cause substantial air pollution, most notably in the form of dust.

Dust evolution can be controlled by appropriate sprinkling in connection with dumping and by immediate greenbelting, oversowing and protective dams. In arid regions where land planting is hardly possible, preventive measures must be taken in the form of restricted use in the prevailing wind direction.

Coal mining releases large quantities of methane (CH4), one of the most notorious "greenhouse gases". The best way to control methane is to "drill and extract" (with subsequent utilization). Particulate solids in the vitiated air from underground mines can be extensively eliminated by filtration.

2.3.2 Water

The pH of mine waters, particularly in the presence of sulfidic ores, can range below 5.5 (acidic). Adherence to the limits prescribed for sulfates, chlorides and metals is essential.

If the groundwater is being used as drinking water and ore is being discharged into a body of surface water, the relevant values must be monitored. It is important to know which anions and cations can occur in mine water and which of them constitute potential hazards on the basis of their concentration or toxicity.

It is also important to mention that heaps of material extracted from an underground mine are liable to contain high concentrations of chlorides and sulfates and that, in a humid climate, such salts can be leached out by precipitation.

Whenever minewater is discharged into a body of surface water, care must be taken to avoid damaging any sensitive ecosystems and to ensure that no long-term accumulation of pollutants occurs in the sediment and that overall use of the water in question, e.g., for fishing purposes, is not impaired.

Marine pollution and alteration of the ocean floor or fishing/spawning grounds can result from the conveyance of polluted water through rivers leading to the coast.

Finally, underground mining consumes water for such activities as drilling, gobbing/stowing, hydro-mining, etc.

The measures described in section 2.2.4 (table 2) should be adopted to prevent pollution of surface and groundwater by mine waters.

2.3.3 Subsidence

For the day surface, the most frequent danger resulting from underground mining activities is subsidence, or settling. Subsidence-induced tilt, curvature, thrust, stretch and compression of the day surface can cause damage to buildings and infrastructural facilities as well as to the natural environment. Watercourses such as canals and rivers - and rice paddies, for example - react very sensitively to the slightest change in ground inclination.

Protective measures begin with early regional planning with due consideration of the potential mining-induced consequences of ground subsidence.

Settling can also be avoided or at least reduced by properly lining the mine with support material and backfilling the face workings with rejects and/or the use of certain suitable extraction techniques. Well-planned and controlled extraction allows slow areal settling that is unlikely to damage buildings or public utility lines and facilities.

2.3.4 Dumps, land consumption, landscape

Underground mining activities are usually accompanied by the appearance of large rubbish heaps within the immediate vicinity of the mine, where rejects and other useless material are dumped. The residual metal contents of such material should be ascertained, even though the metal burdens emanating from dressing heaps can be expected to be higher. Frequently, rubbish dumps are difficult to recultivate, and appropriate measures therefore should be included in the working plans.

Underground mines require a certain extent of surface area for the requisite infrastructure (hoists, buildings, workshops, storage areas, power generating equipment, access road, etc.). The aboveground facilities can impair the appearance of the landscape, and relevant architectural measures have limited effects. The establishment of any such industrial complex is bound to alter the landscape in the vicinity of the mining facilities. To the extent that resettlement is necessary, the affected parties must receive appropriate compensation.

Lowering the groundwater level can have detrimental effects on the local vegetation, including the drying out of ponds, streams, etc. Moreover, the local fauna and human population can be adversely affected by a diminishing supply of drinking water as a result of the altered water regimen.

Adequate protection of wetlands against such negative impacts may require the artificial recharge of groundwater, particularly since receding groundwater tends to cause settling, with damage to structures as one likely result.

Finally, vibrations caused by blasting and ground movement are also perceptible aboveground.

2.4 Other consequences of underground mining

Establishing mining operations in remote areas can have the inadvertent effect of opening the area up to uncontrolled settlement and land use. Appropriate planning-stage backup measures are therefore called for.

The intensive use of wood for timbering mines can trigger the large-scale felling of trees and, hence, erosion of the exposed soil. Orderly silvicultural activities in the area around the mine can help prevent such problems, especially if fast-growing species of trees are planted. Nonetheless, long-term effects on the ecosystem remain unavoidable. The use of anchoring techniques and steel supports in underground mines can extensively reduce wood consumption.

The world over, underground mining provides employment almost exclusively for men, because cultural and traditional conceptions forbid women to work underground. If at all, jobs for women are to be found in the areas of mineral processing, marketing and attendant services. Children should never be allowed to work in underground mines. Other social problems can arise in connection with mining if the housing for the miners and their families is either inadequate or not accompanied by the appropriate infrastructure (water, markets, schools, etc.) and if the miners are not covered by social insurance.

3. Notes on the analysis and evaluation of environmental impacts

3.1 Air / climate

The gas contents of air in underground mines is regulated in Germany by pertinent laws such as the mining ordinances (Bergbauverordnung) BVOSt and BVOE of the North Rhine-Westphalian mining inspectorate (Landesoberbergamt LOBA) and its pertinent and specific directives.

For methane (CH4), the following limits apply to free airflow:

more than 0.3 %: tram shutdown
more than 0.5 %: recorded monitoring
more than 1.0 %: electrical equipment shutdown
more than 2.0 %: monitoring equipment shutdown

Gas extraction equipment is subject to measures in accordance with the relevant gas extraction directives.

Carbon monoxide (CO) in concentrations of 50 ppm and higher calls for special rescue, recovery and security measures according to a life-saving plan (Hauptstelle f Grubenrettungswesen der Bergbau-Forschung GmbH, 1982).

Mines must be evacuated if the carbon dioxide (CO2) level reaches 1.0 % or higher.

Nitrous gas levels of 300 ppm NOx, including 30 ppm NO2, allow a maximum exposure time of 5 minutes. A level of 100 ppm NOx (including not more than 10 ppm NO2) extends the maximum exposure time to 15 minutes per shift.

The oxygen content must amount to at least 19 %.

The hydrogen sulfide (H2S) concentration must not exceed 20 ppm.

All gas measurements must be performed using calibrated commercial-type instruments.

The airflow velocity should amount to at least 0.1 m/s in large spaces and at least 1.0 m/s in fast-line sections. The air velocity in levels used for travel (tram levels) should not exceed 6.0 m/s.

Minimum air volumes amount to 6 m3/min per person, plus 3 - 6 m3/min per diesel horsepower for CO levels ranging from 0.06 % to 0.12 %.

Airflow velocities are measured with anemometers, and the airflow volumes are calculated by multiplying the velocity by the cross-sectional area.

The regulations governing gas contents, air volumes and airflow velocities differ from country to country (hard-coal mines in India, mines in Chile, the People's Republic of China, etc.).

3.2 Noise

Underground noise limits can be drawn up along the lines of rules issued by the North Rhine-Westphalian Mines Inspectorate (LOBA) in Dortmund.

The sound intensity level of noise generated by drills should not exceed 106 dB (A) at a distance of 1 m (LOBA Rundverf/I>).

Transgression of a certain reference intensity calls for the use of ear protectors. The 1988 EC directive on noise in mining came into force in Germany in 1992. Noise measuring specifications have been developed by the Westphalian miners' union fund Westfsche Berggewerkschaftskasse in Bochum, and the appropriate measuring instruments are commercially available.

3.3 Dust

In the Federal Republic of Germany, the German Research Foundation (DFG - Deutsche Forschungsgemeinschaft) publishes yearly dust emission limits/standards in the form of occupational exposure limits (MAK-Werte), technical exposure limits (TRK) and biological tolerance values for working materials (BAT). To the extent that the limit values in question are directly relevant to human health, the above or comparable guidelines, e.g., from the World Bank or other international organizations, should be adhered to.

The most important occupational exposure limit, or MAK-value, is that pertaining to fine silica dust, which amounts to 0.15 mg/m3. The corresponding value for siliceous fine dust is 4 mg/m3. In hard-coal mining, the limits for fine silica and siliceous dust presently (as of this writing) amount to 0.60 mg/m3 and 12 mg/m3, respectively, and were scheduled for reduction in 1992. Fine dust is referred to as siliceous if it contains more than 1 % quartz.

The maximum personal dust exposure, measured in mg/m3 x number of shifts worked in five years, shall not exceed 2500. All underground work is classified according to different dust-exposure categories.

Workers suffering from incipient pneumonoconiosis (or anthracosis) may not be exposed to more than 1500 (mg/m3 x number of shifts worked) in the span of five years. In North Rhine-Westphalia, the German land with the largest number of mines, the mining ordinance for hard-coal mines Bergbauverordnung finkohlebergwerke, section 44 - 48, version dating from February 19, 1979) governs the measurements and interpretation.

Table 3 - Miscellaneous dust limits (MAK-values) with mining relevance

Fibers/m³

mg/m³



Asbestos, crocidolite

0.5 x 106*

0.025*



All other types of asbestos-laden fine dust

1 x 106* --

0.05* 2.0*



Beryllium

carcinogenic



Iron-oxide powder

--

6



Fluorspar

--

2.5



Nickel-ore dust (sulfid.)

carcinogenic



Mercury

0.1



Cinnabar

0.01



Titanium dioxide

6



Manganese oxide

1



Uranium compounds

0.25



Determined by means of atomic absorption analysis and X-ray fluorescence analysis. Application to projects in developing countries in accommodation of local measuring techniques and analytical methods (cf. references) is recommended. * technical exposure limit (TRK)





3.4 Water

The discharge of industrial process water and mining effluent is strictly regulated in Europe. The EC Council Directive 80/778 relating to the quality of water intended for human consumption, dated July 16, 1975, supplemented July 15, 1980, lists three water categories requiring less extensive (category A1) or more extensive (categories A2 and A3) treatment. The guideline values (G) and imperative values (I) for the third category are listed in the following table along with the threshold values (TV) and limit values (LV) stipulated by the North-Rhine Westphalian State Agency for Water and Waste (Landesamt fser und Abfall Nordrhein-Westfalen) in the draft ordinance on potable water Trinkwasserverordnung (TVO) dated July 26, 1994, selected on the basis of relevance to deep-mine waters.

Table 4 - Potable water obtainment guidelines

Element

EC-values



NRW (North-Rhine/ Westphalia)



Element

EC-values




NRW






















[g/l]

G

I

TV


LV

[mg/l]


G

I


TV



LV



Fe

-

0.2

-


0.2

Cr


-

0.05


0.03



0.05



Mn

-

0.1

-


0.1

Pb


-

0.05


0.01



0.04



Cu

1

-

0.03


-

Se


-

0.01


-



-



Zn

1

-

0.1


2.0

Hg


0.0005

0.001


-



-



B

1

-

-


-

Ba


-

1


-



-



Mg

-

-

25


50

NO3


25

50


5



11



Na

-

-

50


150

SO4


150

250


120



240



K

-

-

5


12

Cl


200

-


25



-



Ni

-

0.05

0.03


0.05

F


0.7/1.7

1


-



-



As

-

0.1

0.006


0.04







Cd

-

5

2


5

pH


5.5-9





6.5-8




3.5 Soil

Oversown dumps are rarely used for agricultural purposes. In the event that such a use is envisioned, the applicable heavy-metal tolerance values for soils are to be found in the guidelines and directives issued by the Darmstadt-based Verband Deutscher Landwirtschaftlicher Untersuchungs- und Forschungsanstalten (German association of agricultural research and analysis stations) and by the Biologische Bundesanstalt fd- und Forstwirtschaft (Federal Biological Research Centre for Agriculture and Forestry) in Berlin. It is generally necessary to determine the constituents of the dump and any leaching behavior that could impose limits on the available soil utilization options.

4. Interaction with other sectors

With regard to environmental consequences, underground mining is closely linked to a number of other sectors, including in particular:

- prospection and exploration of deposits in preparation for the actual underground extraction activities;
- processing of the raw materials to obtain marketable products, with such processing normally taking place in centralized plants situated directly at or near the mine;
- conversion into electricity in thermal power stations, many of which are located in the near vicinity of brown-coal mining operations;
- building construction and civil engineering as sectors pertinent to establishment of the requisite mining infrastructure and means of transportation to the market. (Mines tend to be found in isolated locations, accordingly intensive construction activities are required.);
- waste disposal, e.g., for thickener sludge, hydraulic oil, spent oil and the like, and problems concerning ultimate disposal;
- water management, since natural water is quantitatively and qualitatively altered by the discharge of mine water into surface waters or groundwater as well as by the extraction of water for use as process water;
- forestry as a bulk provider of timbering wood;
- and, finally, regional development, which consistently derives strong impetus from mining activities.

5. Summary assessment of environmental relevance

In sum, underground mining can be referred to as an activity with substantial impact on the environment. The consequences can be very detrimental to the environment, especially through the extraction of resources, alteration of the rock structure and groundwater regimen, pollution of the air, the effects of noise and dust, pollution of surface water and alteration and disruption of the landscape. Compared to surface mining, underground mining has modest surface area requirements, both for the winning of raw materials and for other industries. With the exception of leftover rubbish dumps, the area in question is only needed for as long as the deep mine remains in operation.

Among the most significant environmental effects of underground mining is its impact on the miners themselves, whose health and safety are quickly and seriously jeopardized, if the protective rules, regulations and measures are not systematically adhered to.

Finally, underground mining has social consequences, especially in connection with speculative forms of mining, e.g., for precious metals or gems.

Many environmental consequences can be moderated but not prevented. Extensive data is needed as a basis for assessing the environmental impacts and designing protective measures; the uncertainty levels are accordingly high. Even the preparatory activities (reconnaissance, prospection and exploration) necessitate good coordination between the relevant environmental impact assessments and their data requirements.

The stipulation, enforcement, monitoring and control of limit values and underground mining operations has, to a certain extent, evolved to exemplary levels. Direct application of limit-value enforcement and monitoring to other countries is only conditionally possible, since the basic prerequisites usually differ. Nevertheless, every attempt should be made to apply and meet standards designed to preclude detrimental effects on man and the environment. Probably the biggest problem from an environmental standpoint are the uncounted "informal" small-scale mining activities employing uncontrolled, inadequate, unsafe methods that also tend to be hazardous to the environment.

Proper and orderly mining operations require stringent supervision (routine measurements, data collection and monitored adherence to essential limit values). That, in turn, calls for competent executing agencies.

6. References

General Literature

Arndt, P., Luttig, G.W.: Mineral resources, extraction, environmental protection and land-use planning in the industrial and developing countries. Stuttgart 1987.

Bender, F. (Ed.), 1984: Geologie der Kohlenwasserstoffe, Hydrogeologie, Ingenieurgeologie, Angewandte Geowissenschaften in Raumplanung und Umweltschutz. - In: Angewandte Geowissenschaften III: 674 pages; Stuttgart (Enke).

Bundesberggesetz (B Berg G) - 2. Auflage, Gl-Verlag, Essen 1989.

Deutsche Forschungsgemeinschaft: Maximale Arbeitsplatz-Konzentrationen und Biologische Arbeitsstofftoleranzwerte, Weinheim 1990.

Down, C. G.; Stocks, J.: Environmental Impact of Mining. Applied Science Publishers Ltd., London 1977.

EEC 85/337: Council Directive of 27 June 1985 on the assessment of the effects of certain public and private projects on the environment - Off. J. no. L175, 05/07/85, p. 0040.

Environmental impact of iron ore mining and control. Jain N.C.J. Mines Metals Fuels, vol. 29, no. 7/8, July/Aug. 1981.

Environmental monitoring and control. Wld. Min. Equip., vol. 10, no. 5, May 1986.

Franke, H., Guntermann, J. und Paersch, M.: Kohle und Umwelt, Gl-Verlag, Essen, 1989.

Inter-American Development Bank - Environmental Checklist fing Projects.

Johnson, M.S., Mortimer A.M., comps.: Environmental aspects of metalliferous mining. A select bibliography. Letchworth, Herts.: Technical Communications, 1987.

Jones, S.G.: Environmental aspects of mining developments in Papua New Guinea. Prepr. Soc. Min. Engrs. AIME, no. 88 - 155, 1988.

Kelly, M.; assisted by Allison, W.J., Garman, A.R., Symon, C.J.: Mining and the freshwater environment. (Elsevier Applied Science)

Klima-Bergverordnung (Klima Berg V), Gl-Verlag, Essen 1983.

Lambert, C.M., comp.: Environmental impact assessment, a select list of references based on the DOE/DTp. London, Department of the Environment and Department of Transport Library, 1981.

Rawert, H.: Die Erschlieng neuer Abbraure als landes- und regionalplanerisches Problem - das Beispiel Haard. In: Markscheidewesen 86 (1979), Nr. 2, p. 31 - 41.

Schmidt, G.: Umweltvertrichkeitsprbei Projekten des Bergbaus. Gl 125 (1989) Nr. 5/6.

Sengupta, M.: Mine Environmental Engineering, Volume I and II, CRC Press, Inc., Boca Raton, Florida, 1990.

Servicio Nacional de Geologia y mineria - Chile: Reglamento de Seguridad Minera. Decreto Supremo No. 72 of October 21, 1985, Ministerio de Mineria, 1988.

Solving environmental problems. World Min. Equip., vol. 9, no. 6, June 1985.

Stein, V.: Bergbau und Umwelt, Erzmetall 37, 1984 Nr. 1, p. 9 - 14.

United Nations Department of Technical Cooperation for Development (UNDTCD): Proceedings International Round Table for Mining and Environment, DSE Berlin, 1991.

World Health Organisation: Environmental pollution control in relation to development, report of a WHO Expert Committee. (World Health Organisation technical report series, no. 178). Geneva 1985.

Specialized Literature

Methane

Landesoberbergamt Dortmund: Rundverf33-111.15/7455/64-17.2.65; Bergbauverordnung Steinkohle (BVOSt) § 158, § 150; Bergbauverordnung Erzbergwerke (BVOE), § 97; Sonderbewetterungsrichtlinien; Gebirgsschlagrichtlinien; Gasausbruchrichtlinien; Gasabsaugrichtlinien

Carbon Monoxide

Landesoberbergamt Dortmund: BVOSt § 150.

Plan fbenrettungswesen, Hauptstelle f Grubenrettungswesen der Bergbau-Forschung GmbH, Essen, 1982.

Carbon Dioxide

Landesoberbergamt Dortmund: BVOSt, § 150.

Hydrogen Sulfide

Landesoberbergamt Dortmund: BVOSt, § 150.

Oxides of Nitrogen

Landesoberbergamt Dortmund: Sprengschadenrichtlinie.

Air Velocity

Landesoberbergamt Dortmund: BVOE, § 19; BVOSt, § 151; Sonderbewetterungsrichtlinien.

Airflow

Landesoberbergamt Dortmund: BVOSt, § 150.

Temperatures

Landesoberbergamt Dortmund: Klima-Bergverordnung, § 3.

Noise

Landesoberbergamt Dortmund: Maahmen f Lschutz Kleinkaliber-Bohrger (Bohrhammer, Drehbohrmaschinen), Rundverf12.21.11-4-7 (SB1.A 2.4).

Westfsche Berggewerkschaftskassen, Bochum: Gerchmeorschriften DIN 45, 365; 52 Gruben-Diesellokomotiven; 53 Dieselkatzen; 54 Gruben-Gleislos-Fahrzeuge; 55 Rangierkatzen.

Dust

Landesoberbergamt Dortmund: BVOSt, § 44 bis 48, mit Plan f Staubmessungen an ortsfesten Metellen zur Feststellung und zur gravimetrischen Beurteilung der Feinstaubbelastung, MAK und BAT.

Water

Landesamt fser und Abfall Nordrhein-Westfalen: Grundwasserbericht 84/85, Dorf 10/85.

EEC 75/448: Council Directive of 16 June 1975 concerning the quality required of surface water intended for the abstraction of drinking water in the Member States - Off J. no. L194, 25/07/75, p. 0026

EEC 80/778: Council Directive of 15 July 1980 relating to the quality of water intended for human consumption - Off. J. no. 2229, 30/08/80, p. 0011.

Dumps, Soil

Kloke, A.: Orientierungsdaten ferierbare Gesamtgehalte einiger Elemente in Kulturb, Mitteilungen des Verbandes deutscher landwirtschaftlicher Untersuchungs- und Forschungsanstalten, Heft 1 - 3. Januar, Juni 1980.

Kloke, A.: Die Bedeutung von Richt- und Grenzwerten fwermetalle in B und Pflanzen, Mitteilungen der Biologischen Bundesanstalt fd- und Forstwirtschaft, Berlin-Dahlem, Heft 223, Oktober 1984.

Stein, V.: Anleitung zur Rekultivierung von Steinbrund Gruben der Stein und Erden Industrie, K Deutscher Institutsverlag, 1985.

er die Schwermetallbelastung von B, Pflanzenschutzamt Berlin, 1985.

Clarifying Ponds

Davis, R.D.; Hucker, G.; L'Hermite, P.: Environmental Effects of Organic and Inorganic Contaminants in Sewage Sludge, Commission of the European Communities, 25./26.05.1982, Reidel D. Publishing Company Dordrecht, Boston, London.