Kayenta Mine facts for kids
| Location | |
|---|---|
 Kayenta mine
|
|
| Location | Navajo Nation, US |
| State | Arizona |
| Country | United States |
| Coordinates | 36°31′36″N 110°25′52″W / 36.52667°N 110.43111°W |
| History | |
| Opened | 1973 |
| Closed | 2019 |
| Owner | |
| Company | Peabody Energy |
| Website | http://www.peabodyenergy.com |
The Kayenta mine was a large surface coal mine in northern Arizona, on the land of the Navajo Nation. It was run by Peabody Western Coal Company, a part of Peabody Energy, from 1973 to 2019. Each year, about 400 acres of land were mined and then restored. The mine provided about 8 million tons of coal annually to the Navajo Generating Station, a power plant that made electricity.
Contents
History of the Kayenta Mine
The Kayenta mine was located near Black Mesa. This is a large highland area in northeast Arizona. It contains many coal deposits.
Early Coal Use
For hundreds of years, since about 1300 AD, the Hopi people used coal from this area. They used it for firing pottery and for heating their homes. In the early 1900s, small underground mines began operating. These mines supplied coal to local schools and communities.
Developing the Mines
In 1950, a law was passed to help the Navajo and Hopi reservations. This law aimed to improve their economies and use their natural resources better. Because of this, the coal deposits of Black Mesa were studied more closely.
In the early 1960s, Peabody Coal Company explored the area. They wanted to find places where coal could be mined easily and affordably.
Mining Leases and Operations
In 1964 and 1966, Peabody signed agreements with the Navajo and Hopi tribes. These agreements allowed them to mine coal on over 64,000 acres of land. Even when the land was later divided between the tribes, both tribes kept an equal share in the coal and other minerals.
Peabody developed two separate mines in this area. The Black Mesa mine started in 1970. It sent coal to the Mohave Generating Station in Nevada. The Kayenta mine began operating in 1973. It supplied coal to the Navajo Generating Station in Arizona.
The locations of the mines were chosen carefully. They were placed near points where coal could be moved easily. The mines and their facilities were known together as the Black Mesa Complex.
In 1982, the U.S. Office of Surface Mining approved the mining and land restoration plans for both mines. The permit for the Kayenta Mine was last renewed in 2012.
Mine Closure
In 2005, the Black Mesa Mine stopped producing coal. This happened when the Mohave Generating Station closed down. After that, the Kayenta Mine was the only active mine in the area.
By June 2019, the Kayenta mine began reducing its staff. This was because the Navajo Generating Station was also going to close. The mine delivered its last coal in August 2019. The power station closed in November 2019. These closures greatly reduced the Hopi tribe's budget.
What Kind of Coal Was Mined?
The coal mined at Kayenta came from a rock layer called the Wepo formation. This was the top coal-bearing layer on Black Mesa. The coal was found in several layers, usually 3 to 15 feet thick. These layers were typically within 130 feet of the surface.
The coal was a type called low-sulfur, high volatile C bituminous. This means it had a high heat content of about 10,820 BTU per pound. It also had a low ash content of 10.4% and a low sulfur content of 0.63%. The amount of mercury in the coal was also very low.
How the Mine Operated
Coal was removed using a method called open cut or strip mining. This process involves several steps.
Mining Process
First, the topsoil was carefully removed. This soil was either placed on areas that had already been mined and reshaped, or stored for later use. Then, the rock and soil above the coal, called overburden, was blasted to loosen it. Large electric draglines then removed most of this overburden. This exposed the coal layers.
Next, excavators, loaders, and haul trucks dug up the exposed coal. The coal was taken to a collection point. There, it was crushed and loaded onto a 17-mile-long conveyor belt.
The conveyor belt carried the coal to silos where it was loaded into BM&LP train cars. These trains then took the coal to the Navajo Generating Station.
Land Use and Relocation
Less than half of the total leased area was disturbed by mining activities. People were still allowed to use the land for traditional activities, as long as it was safe and away from active mining.
In 2010, about 83 families lived within the leased area. Four of these families were in an area planned for future mining. For families who needed to move, Peabody helped them relocate. They also paid them for any land they lost for grazing due to mining.
Protecting the Environment
The Kayenta mine had many plans and actions in place to protect the environment.
Protecting Ancient Sites
From 1967 to 1986, a very large archaeological project took place at Black Mesa. Peabody Coal Company helped with this project. Its goal was to find, protect, or move ancient artifacts within the mining area. Since 1986, Peabody continued to test for and protect archaeological sites before mining began. Mining operations were also changed to avoid places considered sacred or ceremonial.
Keeping the Air Clean
To protect air quality, the mine used several methods. Water sprays and sprinklers were used on dirt roads and disturbed areas to control dust. Enclosures and water sprays were used at conveyor belt transfer points. Special filters called baghouses were used on coal storage silos.
The Navajo Nation Environmental Protection Agency (NNEPA) monitored and enforced these rules. Peabody also had a network of monitors to check dust levels. This ensured the mine followed national air quality standards.
Managing Water Resources
Two main dry riverbeds, called washes, passed through the mine area. These were Moenkopi Wash and Dinnebito Wash. They eventually flowed into the Little Colorado River. Mining did not happen directly in these washes. However, rainwater runoff from mined areas could affect the water quality.
To prevent water pollution, the mine built sedimentation ponds. These ponds helped clean the water before it entered the washes. Water quality was monitored at these ponds, as well as at livestock watering ponds and other runoff points.
The mine also pumped about 1240 acre-feet of groundwater each year from the Navajo aquifer. This water was mainly used for dust control. Some water was also given to local residents. Before 2005, the Black Mesa mine used groundwater to transport coal through a long pipeline.
Restoring Mined Lands
Once a section of land was mined, it was carefully restored. This process is called reclamation.
The Restoration Process
The mined-out area was filled back in and reshaped to look like it did before. Then, suitable soil layers, including topsoil, were added to create a four-foot-thick area where plant roots could grow. After that, the land was seeded with plants. This helped restore it for grazing animals, wildlife, and growing traditional plants.
The restored areas were watched for at least 10 years. This was to fix any erosion problems and control unwanted weeds. It also made sure the plants were fully established before animals could graze there again.
Success of Reclamation
By 2012, more than 15,000 acres had been restored at the Black Mesa Complex. Also, 39 permanent ponds were created for livestock and wildlife.
The U.S. Office of Surface Mining recognized the mine's reclamation efforts with several awards. These included awards for reclamation excellence in 1998 and 2005, and for cultural, historic, and archaeological preservation in 2002. They also received "good neighbor" awards in 2003 and 2005.
