Coal - Energy Policy Analysis: A Conceptual Framework - page 26

recovery system is included in the preparation plant. Fine coal particulates of less than two
millimeters contain the same heat value as larger pieces of coal and are highly combustible.
Consequently, coal fines are routinely recovered and sold as part of the product shipped from
mines in the United States (Hamilton 2005, 158, 144). Both waste piles and sediment ponds
are sources of airborne fugitive dust, particularly in dry regions. Coal cleaning also generates
dust in and around the plant during transport, storage, transfer, and processing. Airborne emis-
sions from thermal dryers include combustion products from coal-fired furnaces, particulates,
and heavy metals (Nunenkamp 1976). Emissions can adversely impact visibility in the im-
mediate vicinity of the dryer and may negatively affect local flora and fauna with particulate
deposition.
Land areas occupied by the preparation plant and associated disposal areas entail loss of
wildlife habitat. With low pH conditions common at these sites, plant growth is inhibited and
sometimes limited to acid-tolerant species. If the water table is lowered by diversion of water
for processing activities, nearby ponds and streams may dry up, causing a further loss of habitat.
The discharge or runoff of acid waters from coal-washing plants has impacts similar to those of
acid mine drainage (Christman et al. 1980). Noise in coal preparation plants results from use
of heavy industrial machinery that must be quieted to some extent or contained inside build-
ings to meet existing standards governing allowable noise levels in industrial environments
(Christman et al. 1980).
COAL TRANSPORTATION
Transporting coal from a mine to the point of combustion requires trucks, barges, trains, and pipe-
lines utilized in various combinations, with attendant safety, environmental, and social impacts.
Foremost are consumption of diesel and gasoline fuels, air pollution, and deaths and injuries from
transportation accidents. The principal environmental impacts of coal transportation are ambient
air quality deterioration resulting from loading and unloading operations and fugitive particulate
emissions during rail, barge, and truck transport. Water quality deterioration is of concern for
slurry pipeline and barge operations. Social impacts stem primarily from increased congestion in
rail, barge, and truck operation.
Rail
Of the billion tons of coal shipped annually to utilities and other industrial users, more than half
is transported by rail. A typical coal unit train consists of approximately a hundred 100-ton coal
cars and five 3,000-horsepower diesel locomotives (Rifas and White 1976). Fugitive dust release is
unavoidable in transporting coal by rail. Although hoppers can be covered to dampen dust release,
the usual practice is to carry loads uncovered. A variety of light oil coatings may be sprayed on
coal after loading to prevent loss of fine coal particulates during transport. The principal emissions
that result from combustion of diesel fuel in locomotives are particulate matter, sulfur oxides,
carbon monoxide, hydrocarbons, nitrogen oxides, aldehydes, and organic acids. These must be
controlled pursuant to applicable air quality standards for mobile sources. Rail transport has the
added problems of noise and vibration, accidents with vehicles at rail crossings, excessive wear
of rail and roadbed due to the weight of unit trains, and congestion of the rail network. Of these
effects, the most serious and most quantifiable is accidents at grade crossings. It has been estimated
that approximately 0.79 deaths and 8.8 injuries result from every million tons of coal transported
by rail (Christman et al. 1980, 191).