Cleaning Up

Open pit mining methods are used to expose and extract the coal seams. This can involve diverting streams around the site, and removing trees, soil and overburden to retrieve coal that may be more than 200 metres underground. This significant alteration of the landscape and ecosystem makes reclamation of an open pit mine a special challenge.

There are several factors that limit the ability to reclaim an open pit site to its previously undisturbed condition. The climactic conditions in mountainous areas (especially subalpine and alpine) are generally very limiting to some natural processes. Soil formation is typically slow, and the resultant thin soils tend to be rocks and of poor quality. In turn, the cooler temperatures, short growing season, drying winds and poor soils limit the speed and type of plant growth. Topography also plays a major role because steeper slopes generally increase the amount of runoff and soil erosion in exposed areas, further reducing the amount of soil and moisture available for plant growth. The combined effect of these factors means that regrowth on reclaimed lands occurs slowly. 

Contouring of the land, grading of overburden and soil, seeding with grass and legume mixtures, and extensive fertilization are designed to speed plant colonization and plant development on reclaimed mine sites. When a ground cover is well established, seedling trees can be planted in locations considered optimum for tree growth. Streams that were diverted are typically re-routed through their natural valley, and habitat enhancement methods are used to provide quality fish habitat. Depleted mine pits may be filled with water and stocked with fish to provide recreational fishing lakes where none existed previously. These reclamation techniques have proven successful in helping to restore mined areas, hastening their colonization by native plants and animals and subsequent use by people.