The owner or operator of an existing nonferrous smelter shall not permit, cause, suffer or allow the establishment, operation, or use of storage piles for copper ore concentrate, copper precipitate, lime or limestone, or fine silica flux materials within the boundary of the smelter unless the storage and associated materials handling areas are enclosed or other control methods approved by the Department as at least as effective to reduce fugitive particulate matter emissions to the atmosphere are utilized.
N.M. Admin. Code § 20.2.21.109