What Are the Hazards Associated with Open Pit Mining?

Open pit mines pose hazards to both workers and natural resources.

Open pit mines are surface mines exposed to the air. They are excavated by chiseling ever-deeper ledges out of rock from which ore or coal can be mined. Although these mines, according to The Daily Star, are generally safer than underground mines in terms of human fatalities, they still pose considerable hazards to be aware of. Some of these dangers extend to natural resources, as well as posing potential safety concerns to people, and are essential to be aware of for general safety and environmental awareness.

Falls from Ledges

People working in open pit mines are in danger of falling from a "bench," or ledge cut from the rock, while excavating. Such a fall onto a lower ledge or worse--deep into the pit of the mine--can obviously result in injury and may be fatal. Extreme caution must be used when standing on an open pit mine bench to avoid this literal pitfall, and also to keep an eye out for falling rock from above as ore or coal is excavated by heavy machinery or explosives.

Collapse of Underground Mines

A hazard to people unique to open pit mining, according to Australia's Department of Consumer and Employment Protection, is the possibility of collapse of old underground mine shafts beneath an open pit mine. Open pit mines are carefully planned out, but if a pre-existing underground mine is discovered too late while digging is going on, it can cause a potentially deadly structural collapse.

In order to avoid this hazard associated with open pit mining, says the Department, mine planners should carefully survey all records of mining in the area where the open pit mine is to be excavated. Also, if old underground mines are present, planners must take into account that the size, structure and layout of the tunnels may have changed due to factors such as earthquakes, simple structural collapse and flooding.

Environmental Hazards

According to the Daily Star, the nature of an open pit mine--being a massive hole dug into the ground--contributes to a disruption of the nature and appearance of the natural environment around it. Deterioration of the quality of ground water is a possible danger. Also, open pit mines strip the topsoil of the land nearby, and unexpected water runoff from these mines--especially those that excavate coal--can be hazardous to life in nearby rivers and streams.

Although hazards to the environment from open pit mining are not always reversible, they can be minimized. One method to reduce damage to the natural landscape is to fill a depleted mine with water to replace the earth and coal or ore removed. Such lakes can eliminate the hazards associated with wildlife falling into a depleted mine, as well as restore beauty to the landscape.

References

• Mining Basics: Open Pit Mine
• The Daily Star: Keeping an Open Mind About Open Pit Mining
• Dept. of Consumer and Employment Protection (Australia): Open Pit Mining Over Old Workings

Resources

• U.S. Mine Safety and Health Administration