The Center for Land Use Interpretation Newsletter

Black Mesa Coal

A Long, Strange Trip To Fuel the Grid

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.1245Coal 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 photoThe 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).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.1244The Navajo Generating Station, near Page, is fueled by rail car loads of Black Mesa coal. CLUI photoAfter 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.