Field Report by Edward Beale
Though located on a remote mesa
in the Navajo Nation of Arizona, the Black Mesa coal mine
complex is directly linked to the major cities of the Southwest
in a surprising network of elaborate forms of conveyance:
a dedicated railway, a 17 mile long conveyor belt, electrical
transmission cables, and the world's longest slurry pipeline.
The two strip mines on the mesa
are the sole source of coal for two separate power plants,
situated miles away from the mine, and from each other.
These plants in turn provide electricity to Los Angeles,
Phoenix, and elsewhere, through high voltage transmission
lines. In this manner, the large hole forming from the removal
of coal on Black Mesa is the physical byproduct of electrical
consumption in these urban areas.
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Coal
silo at the end of the 17 mile conveyor. The other
end of the conveyor is the Kayenta Mine, on Black
Mesa. Electric-powered rail cars drive through the
base of the silo to be loaded with coal, then travel
75 miles to the Navajo Power Plant near Page.
CLUI photo
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The Black Mesa mine complex is
comprised of two principal mines, covering thousands of
acres on a remote plateau. The southern complex is called
the Black Mesa Mine, and is the origin of the coal slurry
pipeline, and the northern mining area is known as the Kayenta
Mine, which is connected to a railhead by a 17 mile long
conveyor belt. Both mines are operated by the English-owned
Peabody Western Coal Company, which leases the land from
the Navajo and Hopi tribes. Said to be one of the largest
strip mines in America, the mines generate 80% of the Hopi
Tribal government's revenue (about $11 million per year
in royalties).
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Structures
containing the crusher and the origin of the longest
slurry pipeline in the world.
CLUI photo
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The 273 mile long pipeline connects
the Black Mesa Mine to the Mohave Generating Station in
Laughlin, Nevada, and is operated by the Black Mesa Pipeline
Company. It was built by the Southern Pacific Company in
1970, after they decided that a pipeline would be more economical
and feasible method of transporting the coal to the plant
than a railway, the more conventional means of transporting
coal. Buried beneath a minimum of three feet of soil, the
path of the 18" pipeline is barely visible.
The coal removed
from the mine is crushed to a diameter of around one millimeter,
and is mixed with water in holding tanks with agitators,
which keep the coal in suspension in the water. From the
tanks the half water, half coal slurry enters the pipeline
at the first set of pumps, beginning its journey west through
some of the most scenic American desert, passing south of
the Grand Canyon, crossing four mountain ranges, and boosted
by three more pumping stations that keep the water moving.
In order to
do this, the pipeline consumes around a billion gallons
of water annually, and some Hopi communities are claiming
that lakes and groundwater sources are drying up due to
the massive consumption of water by the pipeline. A proposal
to build a water pipeline to bring water from Lake Powell,
70 miles away, is being considered.
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The
Navajo Generating Station, near Page, is fueled by
rail car loads of Black Mesa coal.
CLUI photo
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After three days the slurry reaches
the end of the pipeline, at the Mohave power plant, where
it is held in agitated tanks, for immediate use, and in
drying ponds, for later use. Heated centrifuges are used
to get the water out.
Like the pipeline,
the Mohave Generating Station was constructed around 1970.
Most of the electricity from the plant travels via 500,000
volt lines to the Lugo Substation, near Victorville, on
the outskirts of Los Angeles.
The second
mine on Black Mesa is the Kayenta Mine, which supplies the
Navajo Generating Station, near Lake Powell, in northern
Arizona. Coal travels from the mine on a 17 mile long, elevated
conveyor belt to a large silo, where it is stored and loaded
onto rail cars, on the only railway on the Navajo reservation.
The 75 mile long private railway connects directly to the
power plant, and its only traffic are the coal trains. Three
electric-powered, 80-car trains deliver coal to the plant
every day.
The plant
is located at the site to take advantage of the water at
Lake Powell, which is used as a coolant (though no water
is discharged back into the lake), and to be near the high-tension
transmission line hub at the nearby Glen Canyon Dam, which
distributes the electricity to Las Vegas, Los Angeles, Phoenix,
and other southwestern cities.
