Does MSHA have jurisdiction over inactive mine facilities?

The owner of a coal mine is maintaining one bulk anhydrous ammonia tank and satellite ammonia tanks because of an agreement with the State pursuant to environmental regulations concerning acid mine drainage.  Ammonia is used to treat surface water runoff (raise the pH of the effluent).  The mine is no longer operational as the coal deposits were depleted.  When it was operational, the mine was operated as a surface extraction operation.  Since the mine is not in operation now, is the activity involving treatment of the water with ammonia regulated under Mine Safety and Health Administration (MSHA)?  Does MSHA have jurisdiction of the mine facility now even though it is not operational?

As interpreted by OSHA/MSHA, the purpose of the Federal Mine Safety and Health Act of 1977 is to protect the health and safety of miners working at underground and surface coal and other mines.  Based on the information provided, OSHA/MSHA have advised EPA that it appears that extraction has stopped since the coal reserves appear to be depleted.  In other words, OSHA/MSHA would say that the mine is not operational and permanently abandoned due to the fact that the coal has been mined out and the only activities occurring at the site are activities associated with the treatment of acid mine drainage.  According to MSHA, this type of activity is not the type of activity that would cause MSHA to exercise jurisdiction over the property since the nature of the land has changed from that of a "mine" where the purpose and intent of the mine operator was to exploit the land for minerals.  Thus, MSHA generally would not exercise jurisdiction over such a site.  Therefore, according to OSHA, the activity involving the treatment of water with ammonia may be regulated under the Occupational Safety and Health Act (OSHA) Hazard Communication Standard.  If this activity is regulated under OSHA, and if the facility has any hazardous chemical at or above the thresholds defined under 40 CFR part 370, pursuant to EPCRA, EPA believes the facility would have to report this hazardous chemical as required.