Environment: Stewardship

Photo of grassy hillside.

  • Reclamation/Restoration programs began in 1970
  • 5,500 acres reclaimed
  • 500,000 seedlings transplanted (approx. 25,000 to 30,000 per year)
  • 16,000 lbs. of seeds planted each year
  • 30 tons of fertilizer is spread each year
  • Hydro seeding
  • Aerial seed application


Environmental Stewardship in the Far North

By Cathy Brooks & Bartly Coiley
Reprinted with permission of the publisher, American Coal Council, 2005

Enviromental stewarship in the far north map.Reclamation at Usibelli Coal Mine, Inc. (UCM) calls for a unique and innovative application of technology, equipment, people, and science. Although located in the remote mountainous foothills north of Denali National Park, near Healy, Alaska, the mine contends with the same laws and regulations others in the industry face. Managing the resources can be challenging with the short summer field season and long cold winters.

UCM got its start in 1943 when founder, Emil Usibelli contracted to supply 10,000 tons of coal to a military base located in Fairbanks, Alaska. More than 60 years later, a workforce of 96 UCM employees led by Emil's grandson, Joseph Usibelli, Jr., now ship approximately 1.5 million tons of coal annually to 10 customers, including three interior Alaska military bases. Most of the customers are power plants based in interior Alaska. However, UCM has established relationships in the international market, having sold coal to South Korea since 1984.

The coal found in interior Alaska is a subbituminous coal that comes from three seams of the Suntrana Formation. The coal seams vary in depth from 18 to 30 feet with the interburden ranging from 70 to 125 feet.  The mine operation consists of a dragline and truck/shovel combination. UCM began its land reclamation program in 1970, well ahead of the passage of the 1977 Surface Mining Control and Reclamation Act (SMCRA).

 

Changes in ground cover over time of comerical grass seed on fertillized verburden.UCM worked with Alaska's Department of Natural Resources Division of Mining, Land and Water to establish bond release standards by selecting several sites that were considered successfully revegetated. This helped establish reasonable revegetation goals, which took into consideration the post-mining ground cover, water quality, and wildlife habitat. 
   
Conducting studies with researchers from the University of Alaska, UCM has been able to examine revegetation ranging from the natural reinvasion to actively providing seed, transplants and/or selected growth media to facilitate plant community development. A compilation of results from several studies suggested the following changes in ground cover over time (see Figure 1). The research indicated seeded grasses have a high ground cover at first while the vegetative litter and locals are essentially nonexistent. Over the next five years, ground cover from litter develops from the seeded grasses and then declines for another five years. Meanwhile, groundcover from locals slowly increases, hitting a low point of ground cover from all sources and at the 10-year mark. This could be interpreted as a reclamation failure. However, as depicted on Figure 1, from this point on, ground cover sharply increases. The conclusion is that initial grasses appear to assist soil development, but it takes 10 growing seasons to see the effect.

 

The coal found in interior Alaska is a subbituminous coal that comes from three seams of the Suntrana Formation. The coal seams vary in depth from 18 to 30 feet with the interburden ranging from 70 to 125 feet.

This research and other studies helped to develop a successful reclamation plan. UCM has applied for and received phase II bond release and is in the process of applying for phase III bond release. Research also assisted in developing the mixture of grasses that would provide the necessary ground cover until the slower growing native plants began to flourish. UCM conducts aerial seeding twice during the rapid summer growing season and has experimented with hydro-seeding while continuing to look for innovative ideas. A summer crew, consisting of local college students, transplants approximately 25,000 native shrubs and trees each year. The trees and shrubs planted include spruce, birch, alder, and willow with a few other species depending upon seed availability. During the fall, local grade-school children assist by collecting seeds that are cleaned and germinated for transplanting.

Reclamation is a challenge due to the lack of top soil on north-facing slopes, deep permafrost layers, abbreviated field season (best time for regrading is between September through December), and a high rate of naturally occurring erosion. The spring and summer seasons bring quick moving rain storms with abundant rainfall which challenge soil stability, especially on our 3:1 slopes.

UCM constructed sediment ponds to collect and treat storm water runoff to meet the mine's National Pollutant Discharge Elimination System (NPDES) permit limits. The sediment ponds have been designed into the post-mining land use plan as constructed wetlands. Several access roads will remain in place, something that is in short supply in Alaska. Another post-mining design feature, approved for one area of the mine, is a man-made lake that will be stocked with fish grown in a hatchery. The hatchery will utilize the waste heat from a power plant generating electricity and heat from coal mined at UCM.

UCM has worked for many years with state and federal agencies to develop reclamation standards and permit conditions that are protective, reasonable, and achievable. These permits span eight state and federal agencies, which have responsibility for more than 30 plus environmental permits required to mine coal in Alaska.
 

At the time of publishing this article: Cathy Brooks was a Mine Technician in the Engineering Department at Usibelli Coal Mine.
Bartly Coiley is a Civil Engineer and worked with Permitting at Usibelli Coal Mine.

Before and after photos of a hillside recalmation.