The following are descriptions of some of the hazards associated with abandoned mine land.
The vertical face remaining from the final cut of a surface mining operation. The associated pit may be either water-filled or dry.
Hazardous Water Body
Any strip pit with impounded water, regardless of depth or surface area, is considered an attractive nuisance and is located within close proximity to a populated area, public road, or other areas of intense visitation. The hazard must result from some AML-related feature(s) such as steep or unstable banks and hidden underwater ledges. Hazardous water bodies are generally associated with dangerous highwalls.
Unauthorized use of AML-impacted areas for residential or industrial waste disposal that poses a danger from unsanitary conditions or from the toxic emissions of burning refuse.
Hazardous Equipment or Facilities
Any AML-related dilapidated hazardous equipment or facilities (old engines, mine cars, rails, mine entrance, load-out and processing facilities) located within close proximity to populated areas, along public roads, or other areas of intense visitation.
Any surface expression such as caving, potholes, troughs, tension cracks, or shearing faults caused by AML underground mine voids that damages property and poses a danger to the public.
Acid Mine Drainage
Water that is discharged from mining or mine-related operations which contains high levels of dissolved iron and aluminum sulfates in conjunction with pH values less than 4.5 (acidic). It is produced when oxygen dissolved in water reacts with pyritic (iron sulfide) materials found in association with most coal deposits. Acid mine drainage (AMD) degrades the water quality of streams and water supplies, often to the point of eliminating all biological activity within the stream contaminated with AMD.
The refuse or waste is removed from an underground mine. This includes mine waste, rock, pyrites, slate, or other unmarketable materials that are separated during the cleaning process. Gob piles are generally found at coal load-out and processing facilities.
The filling of a stream bed with AML-originated silt and debris sedimentation carried downstream by surface runoff. The sedimentation causes a blockage of the stream resulting in the flooding of roads and/or residences and posing a danger to improved property and the public.
A surface entrance to a drift, tunnel, adit, or entry that is not sealed or barricaded. It poses a threat when it is located in close proximity to a populated area, public road, or another area of intense visitation.
A vertical or steeply inclined shaft or opening that is not sealed or barricaded, or a subsidence-caused opening that has become a hazard, regardless of proximity to populated areas, a public road, or another area of intense visitation, posing a threat to the public.