Geologic, Hydrologic, and Urban Hazards for Design in Desert Environments - Design with the Desert: Conservation and Sustainable Development - page 106

required. Minerals mined in the region include metals and metalloids, such as gold, silver,
and copper; fossil fuels, particularly coal, natural gas, and oil; materials used in industrial
processes, such as clays, diatomite, and zeolites; gemstones; and materials used to develop
building materials, such as building stone, lime, limestone, gypsum, and sand and gravel.
For nonfuel resource extraction, California is ranked third behind Arizona and Nevada
in the southwestern United States. The economic impact to these three States is enormous:
in Arizona, mining contributes $6.71 billion to the state's economy, which is the largest
contribution of the 50 states and about 10% of U.S. total mineral production.* Copper is
the largest mineral industry, followed by molybdenum products, sand and gravel, and
limestone products. In Nevada and California, mining contributes $5.24 billion (second)
and $4.5 billion (third), respectively. 50 Online map servers provide location information
for most of these mines. † Although the economic benefits of mining are large, the environ-
mental impacts particularly waste management and site rehabilitation associated with the
mining industry are also substantial.
Both surface and subsurface mining have substantial impacts on landscapes that range
from subsidence or collapse features associated with subsurface mining and diversion
or blockages of watercourses with mines and their attendant tailings piles. Viewscape
impacts are substantial and may have some of the largest impacts in terms of regional
planning and design. The environmental impact of mining includes acid mine drainage,
increased sedimentation in channels, contamination of surface and ground water by met-
als, release of toxins such as cyanide, increased dust emission and deposition, and local
impacts, such as contamination from solvents, petroleum, and chemicals used in process-
ing operations. ‡ Water and air pollution are the largest offsite impacts, requiring special
mitigation and (or) warning systems. For example, the town of Green Valley, Arizona, has
special wind forecasts to warn of dust emissions from nearby tailings piles accumulated
from strip mining for copper. §
Mining operations for common building materials typically create large depressions
along the streambeds on the outskirts of urban areas and create a significant amount of fine
particulates, which often contributes to an increased PM 10 levels in the areas surrounding
these operations. In-stream mining for sand and gravel is largely banned in Arizona
because of its impact on channel geometry, particularly bed degradation during floods,
both upstream and downstream from the mining site. Channel erosion has numerous
negative environmental impacts that range from effects on shallow groundwater to
destruction of riparian vegetation.
Pollution from mining operations has lasting impacts to lands, groundwater, surface
water, and air quality, and lengthy and costly rehabilitation is necessary in many cases
to rehabilitate the affected lands to mitigate impacts, particularly those that transport
contaminants offsite. ¶ Mining wastes from both active and inactive mines cause negative
environmental impacts on the land, air, and water.** These include waste generated during
the extraction, beneficiation, and processing of minerals. Most extraction and beneficiation
* http://minerals.usgs.gov/minerals/pubs/mcs/2007/mcs2007.pdf (accessed June 25, 2010) 50 ; http://www.
admmr.state.az.us/ (accessed June 28, 2010).
† For example, mines in Nevada can be mapped using http://www.nbmg.unr.edu/dox/mm/mm97/mm97.htm
(accessed June 25, 2010).
‡ http://www.techtransfer.osmre.gov/NTTMainSite/Library/hbmanual/epa530c/chapter3.pdf (accessed June
28, 2010).
§ http://www.azdeq.gov/environ/air/ozone/gvwind.pdf (accessed June 23, 2010).
¶ http://www.epa.gov/osw/nonhaz/industrial/special/mining/index.htm (accessed June 25, 2010).
** http://www.epa.gov/osw/nonhaz/industrial/special/mining/index.htm (accessed June 28, 2010).