PKAA, El Paso Coal Legacy Project

The EL PASO COAL LEGACY Legacy project involves coal mine-related features, highwalls, shafts/sinkholes, and previously closed mines that need maintenance east of Colorado Springs, CO. The coal mines in this area were operational from the 1880s until the mid-1950s. The primary hazards relating to these old coal mines is surface sinkhole subsidence from ongoing subsurface collapse. Groundwater level fluctuation contributes to the ongoing collapse of these mines. There are also some highwalls left in place after surface mining, which present a risk of falling and encroachment into a seasonal stream channel. Closure methods are backfill, monolithic plug, and surface grading. Imported rockfill and imported fill will be required for these closures.