Abstract

Phosphate mining in the Crawford Mountains began in 1902 and continued until 1972 using underground stope mining and surface strip mining methods. Several unique abandoned mine land problems have resulted. Vertical shafts, inclined shafts, open subsidence holes, and horizontal access into the mines are the primary dangers. An abandoned mine land (AML) hazard inventory performed in 1990 included aerial photography and field reconnaissance; 234 physical hazards were documented. Also found were extensive waste rock piles with a heavy concentration of phosphoric acid generating material, along with exposed highwalls and other barren mining spoils. Morgan Mining and Environmental Consultants estimated a total reclamation cost of $25 million for the entire Crawford Mountains abandoned mine land problem. Ten incremental construction projects have been scheduled for the reclamation work. The first, the Brazier Demonstration Project (1991), was completed at a cost of $330,000. The successful results and experience gained from this project reduced the total estimated reclamation cost to $15 million. The Utah Division of Oil, Gas & Mining has continued the reclamation projects with Molly’s Canyon (1993), Arickaree Mine (1994), Coal Hollow (scheduled for completion in the summer of 1995) and Molly’s Canyon West (scheduled for construction in 1996).