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Since the earliest days of mining, the job of digging coal and other useful materials out of the earth has been considered one of the world's most dangerous occupations.
And, even though mine safety has improved over the years, with technology advances and regulatory activity, the industry still poses many hazards to its workers.
Safety issues
The safety issues facing the mine industry vary according to the type of mine (underground or surface) and whether the mine is a coal or mineral mine. But, many hazards are the same. Here are some of the more common hazards at mine sites:
- Machinery and equipment operation and maintenance is a problem when not maintained in safe operating condition or operated by untrained or unauthorized persons. In addition, repairs or maintenance can lead to injury unless the work is unless the power is off and the machinery is blocked against motion (except where machinery motion is necessary to make adjustments.) Inoperable horns or other audible warning devices for self-propelled mobile equipment pose hazards to mine workers.
- Moving machine parts also pose hazards unless they are guarded with adequately constructed, installed, and maintained guards to provide the required protection.
- Accumulations of combustible materials such as grease, lubricants, paints, or flammable liquids can create a fire hazard in mine work. For underground coal mines, coal dust, including float coal dust deposited on rock-dusted surfaces, loose coal, and other combustible materials, must not be permitted to accumulate in active workings, or on diesel- powered and electric equipment therein.
- Miners also face electrical hazards. Electrical conductors must be of a sufficient size and current-carrying capacity to ensure that a rise in temperature resulting from normal operations will not damage the insulating materials. Electrical conductors exposed to mechanical damage must be protected.
All electric equipment must be frequently examined, tested, and properly maintained by a qualified person to assure safe operating conditions.
Environmental concerns
While mining operations are subject to varying levels of scrutiny, all operations must comply with applicable state and federal laws, including air and water quality standards such as those established under the Clean Air Act (CAA), Clean Water Act (CWA), Emergency Planning and Community Right-to-Know Act (EPCRA), and standards for the disposal of solid waste under the Resource Conservation and Recovery Act (RCRA).
Under the Clean Water Act, National Pollution Discharge Elimination System (NPDES) permits must be acquired before any pollutant can be discharged from a point source into U.S. waters. The Environmental Protection Agency (EPA) has established national technology-based effluent limitation guidelines for ore mining and dressing operations.
Contaminated stormwater runoff from some mining operations has been documented as causing water quality degradation. EPA regulations specifically address point source discharges of storm water from industrial facilities, including active and inactive/abandoned mine sites. In addition, these regulations require NPDES permits for all discharges of contaminated storm water.
In addition to applicable general CWA requirements, active mineral mining and processing operations are subject to the requirements contained in 40 CFR Part 436, EPA Effluent Guidelines and Standards for Mineral Mining and Processing.
The Safe Drinking Water Act may also apply to mine operations if primary drinking water sources and Class 3 wells are affected by mine wastewater releases. EPA regulates cadmium, lead, and arsenic under its primary drinking water standards (40 CFR 141.11(b)), and regulates copper, iron, manganese, and zinc under its secondary drinking water standards (40 CFR 143.3).
Wastes generated by mines that may be subject to hazardous waste regulation may include used oil, polychlorinated biphenyls, discarded commercial chemicals, cleaning solvents, filters, empty drums, laboratory wastes, and general refuse. Some wastes from the extraction and beneficiation of ores and minerals are exempt from the hazardous waste rules.
Mining companies may be liable under CERCLA for the release or threat of release of hazardous substances, covering releases to air, surface water, groundwater, and soils. Many mines, where practices did not incorporate the safeguards now required under the CWA, allowed runoff from mine and tailings sites to flow into nearby streams and lakes. Even newer mines, which have been subject to CWA regulations, have been targeted for CERCLA enforcement. Mine owners may also be liable for damages to natural resources as a result of mining activity.
Under the CAA, New Source Performance Standards (NSPS) applicable to metallic mineral-processing plants have been established (40 CFR 60 Subpart LL). These standards regulate emissions of particulate matter in metal mining operations in crushers, conveyor belt transfer points, thermal dryers, product packaging stations, storage bins, truck loading and unloading stations, and rail car loading and unloading. Although all underground mining facilities are exempt from these provisions, fugitive dust emissions from mining activities may be regulated (usually by requiring dust suppression management activities) through state permit programs established to meet federal National Ambient Air Quality Standards (NAAQS).
Although nonmetallic mining operations are not specifically regulated by the CAA, businesses involved in the processing of the minerals are regulated. 40 CFR Part 60 Subpart OOO, Standards of Performance for Nonmetallic Mineral Processing Plants, and 40 CFR Part 60 Subpart UUU, Standards of Performance for Calciners and Dryers in Mineral Industries, require these industries to control or reduce emissions of particulate matter and impose specific monitoring, recordkeeping, and reporting requirements.