Safety Fact Sheet.pdf

Illinois Department of Natural Resources Office of Mines and Minerals Abandoned Mined Lands Reclamation Division

SAFETY FACT SHEET

The purpose of this fact sheet is to alert contractors, consulting engineers, landowners and the general public to the safety hazards which abandoned mine sites pose. While not intended to be a comprehensive safety manual, this document will provide some general guidelines for working or living near abandoned mines.

Mine Openings

Open mine shafts or other portals to underground mines are a problem commonly found at abandoned sites. In addition to the obvious hazard that an open, vertical shaft presents, seemingly sound shafts may, in fact, contain unstable fill material or be covered by poorly-constructed, deteriorated caps or seals. Such seals can fail without notice and extreme care should be taken to avoid unnecessary ground disturbance around old shafts.

Horizontal shafts, often called drifts or adits, can provide easy access to underground mines and, because there is no vertical drop, may seem harmless.

However, abandoned mines frequently contain heavy concentrations of harmful gases and may be severely deficient in oxygen. They may also contain other physical hazards such as flooded rooms or fractured and falling roofs, and may house a variety of vermin.

Mine Gas

Underground mine atmospheres frequently contain explosive or toxic gases such as methane and hydrogen sulfide. These gases can make their way to the surface either through shafts, fissures, or in the case of a very shallow mine, directly through the ground. A mere 5-15 percent concentration of methane escaping to the surface is highly combustible and explosive under certain conditions.

Consequently, smoking or use of any open flame near a mine opening of any type must be avoided. While methane is both flammable and an asphyxiant, hydrogen sulfide is poisonous and quite deadly at significantly lower concentrations. For this reason alone, abandoned underground coal mines should never be entered.

Mine Refuse

"Gob" refers to the coarse refuse, usually deposited in large, steep piles, stemming from the coal sorting process. "Slurry" is defined as the fine, silty refuse which remains after the coal washing process is completed. Both types of refuse have the potential to ignite and burn slowly for long periods of time due to their coal content. While some burning refuse areas are easily identified by smoke, ash or burned coal particles, other areas may be burning below the surface and exhibit no visible signs. As a result, extreme caution should be exercised when walking or driving on or near gob piles or slurry impoundments.

Highwalls

Surface mining for coal often results in a final cut pit with steep, sheer walls surrounding a flooded impoundment. These walls pose a unique hazard because of their vertical height above the water level, and because of their erosive nature resulting from their unstable slopes.

Drownings have occurred when individuals slipped into the pits and were unable to climb out. In some areas, final cuts do not fill with water, presenting a hazard due to the vertical drop.

Mine Buildings

Many abandoned mines include old machinery, buildings and equipment referred to collectively as the "tipple area". Abandoned mine structures are frequently quite deteriorated and subject to collapse. Coal hoppers, auger pits and underground steam ducts can also be found at most tipple sites and are sometimes obscured by vegetative growth or rubble accumulation, creating a trap-like situation.

Toxic Substances

Industrial chemicals and other harmful substances occasionally have been found at abandoned mine sites.

Coal oil, abandoned transformers containing PCB's, and asbestos insulation in tipple buildings are not uncommon.

Abandoned mine sites also attract illegal dumping of other substances not related to the mining operation, but equally as dangerous. Workers should consider any unknown substance to be potentially harmful until determined to be otherwise.

Safety Precautions

As with any construction site, standard safety precautions required by the Occupational Safety and Health Administration (OSHA) should be strictly followed when performing reclamation work. These include, but are not limited to, wearing hard hats, safety glasses and steel-toed boots. Be aware of any electrical or other cables on site and always take the necessary water safety precautions when working around water impoundments. Always contact J.U.L.I.E. before excavating.

The reclamation of abandoned mines sometimes involves the use of chemicals such as alkali materials and chemical grouts. Always follow the directions provided in the Manufacturer's Safety Data Sheet when ha1ndling these and other materials.

Finally, abandoned mine reclamation generally requires the use of bulldozers, pan scrapers, large backhoes, heavy-duty trucks and other heavy equipment.

Individual pieces must meet all OSHA standards and must never be operated in a negligent or reckless manner.

Individuals on the construction site, whether on foot or in a road vehicle, should always give the heavy equipment operator the right-of-way since visibility is often quite limited.