FRUITLAND— When it comes to reclamation, Navajo Mine is following in the footsteps of its cousin, the La Plata Mine, using a process called "geomorphic reclamation."
Geomorphic reclamation is a method of returning the land to its original condition by recreating surface contours that existed prior to mining activities. The goal is to restore the natural functions of the land, particularly in relation to water runoff.
Navajo Mine is a 34,000-acre open-pit coal mine operated by BHP Billiton New Mexico Coal on the Navajo reservation.
There are three draglines at the mine with pits that can go as deep as 270 feet.
The company first used geomorphic reclamation at the La Plata Mine, located 16 miles north of Farmington, which supplied coal to the San Juan Generating Station from 1986 to 2002.
Over La Plata Mine's lifetime, 42 million tons of coal was extracted and delivered to the power plant.
When coal production ended, full-time reclamation of the 2,066-acre mine site started. The project restored the rolling hills and valleys that sustain native vegetation.
This reclamation effort resulted in La Plata Mine receiving the Excellence in Reclamation award from the Mining and Minerals Division of the New Mexico Energy, Minerals and Natural Resources Department and the 2009 National Award for Excellence in Surface Coal Mining from the Office of Surface Mining.
At Navajo Mine, 227 acres already have been reclaimed in the Pinto, Barber and Chinde areas using geomorphic reclamation.
The mine's oldest geomorphic reclamation site is Barber Ramp 3, which was regraded at the end of 2006, top soiled in 2008 and seeded in 2009.
During an Oct. 9 visit to the mine, production planner Cassandra Brandt stood beside the dirt road that runs along the Chinde site, located in Area 2.
Irrigation pipes and feeders crisscross the land in a grid pattern and provide water to seeds planted last summer after the area was regraded and top soil was laid down.
Healthy plants crowded the irrigated area, which contrasted with the more sparsely vegetated natural areas. After a watering period that allows the vegetation to take root, the area will look like the natural landscapes, mine officials said.
As Brandt looked at the area, she explained that the principle of geomorphic reclamation is to mimic natural landscape functions, for example, the arroyos that were constructed to channel water in a meandering course that ultimately will cut its own route. During a recent downpour, the contours ensured that the topsoil and seeds were not washed away.
"We've worked hard at implementing it in Area 2," Brandt said.
Ken Logan, an analyst and assistant to the general manager, said the mixture of indigenous seeds were planted and will be watered for a minimum of two years with water delivered from Morgan Lake, which is next to the Four Corners Power Plant.
Water is also used to suppress dust associated with mining operations.
"That's why we irrigate for two years, to get it as strong (as possible, and) then it relies on Changing Woman," Logan said.
In Navajo stories, Changing Woman represents the changing seasons by growing into an old woman in the winter and a young woman in the spring.
The purpose of introducing geomorphic reclamation at La Plata and Navajo mines was manyfold, said Brent Musslewhite, who works with BHP Billiton's environmental services.
Musslewhite said areas where conventional reclamation practices were used require continuing maintenance but geomorphic reclamation represents a different approach.
Geomorphic reclamation, he said, allows the reclaimed area to be stabilized from excessive erosion, restores topography, and enhances vegetation diversity and wildlife usage.
Other forms of reclamation employed at Navajo Mine are referred to as "traditional" or "conventional," and differ from geomorphic reclamation by incorporating hard engineering controls such as riprap lined channels, gradient terraces and rock-lined down-drains to convey storm water into the land form design, Musslewhite said.
The mine's reclamation efforts also include creating wildlife habitat. A pile of large rocks provides shelter for small animals that are food for the larger ones.
Annual wildlife surveys at Navajo Mine have identified numerous animals in the reclaimed areas. Among them are bobcats, coyotes, black-tailed jack rabbits, desert cottontails, hawks, rattlesnakes and lizards.
The new approach aligns with BHP Billiton's commitment to sustainability and ensuring the lands used for mining continue to add value to communities after mining ends, Musslewhite said.