Environmental Engineering Reference
In-Depth Information
Surface
mining
Soil erosion, acid drainage*
Gravel, sand, coal, oil sands
Mountaintop
removal
Deforestation, soil erosion, complete modification of local
communities
Coal
Placer min-
ing
Excessive debris in streams inhibiting biotic community,
erosion of stream banks, loss of riparian habitat
Gems, gold
Open-pit
mining
Complete ecosystem destruction, acid drainage*
Copper, iron, diamonds, gold, coal
Subsurface
mining
Gold, copper, uranium, zinc, lead,
nickel, coal, other metals
Health hazards to miners, acid drainage*
* Acid drainage occurs when sulfuric acid is created by the exposure of oxygen and water to sulfide compounds, which causes a re-
action. This natural process is accelerated by the increased exposure of rock surfaces during mining processes. In some situations,
the leakage from acid drainage could continue for hundreds of years and has the potential to filter into groundwater.
While the specific negative impacts of mining techniques are noted in the table above, all mining processes
cause habitat alteration and degrade ecosystems for the short term and potentially the long term. Ecosystem
changes due to mining can include deforestation, soil removal, soil erosion, stream alteration, and the displace-
ment of many organisms.
Mining Oceans
The ocean floor provides many resources, and the extraction of these resources is a relatively recent human en-
deavor. Sand, gravel, calcium carbonate, sulfur, phosphorites, silica, and valuable ores are all mined from the
ocean bottom.
Manganese nodules,
a unique creation in the benthic environment, are ball-like structures cre-
ated on the ocean floor. They contain manganese, along with many other minerals in smaller amounts, such as
copper, zinc, and nickel. Mining of manganese nodules can be very destructive, as it disrupts and relocates
large amounts of sediment. Also, the mining processes remove benthic organisms and can destroy structures on
the ocean floor.
Mining Reclamation
Mining operations are destructive to the land, so the
reclamation,
or restoration, of the land after mining activ-
ities are completed can be a difficult and costly process. The process of reclamation varies depending on the
type of mine, type of operations, location, and extent of environmental destruction. Metal mining can produce
heavy metal and acid contamination, which can affect surface water and groundwater as well as potentially be-
ing toxic to humans and wildlife. With mining practices that disturb the surface of the land, it is not always
possible to return the land back to its original state. One technique to restore land disturbed by mining is to re-
place lost topsoil with new topsoil reclaimed from agriculture.
Some mining sites are contaminated with hazardous wastes that require specialized cleaning techniques, as
specified by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Su-
perfund. The cleanup of
Superfund
sites is the job of the federal government and paid for by a tax on the
chemical and petroleum industries.
Mining Laws and Treaties
The General Mining Act of 1872 gives people the right to prospect on public lands, serving as the basis for fur-
ther mining regulations. Mining operations also must comply with federal laws such as the Surface Mining
