Description: The minfile_producer_compilation layer described below includes all MINFILE occurrences that
have any indication of actual mining. For some use cases, that is too permissive. This layer is a
more selective version, requiring a MINFILE occurrence to also have been issued a permit
number at some point, or being given a mine name or mine plan number, in a government
database, or having nonzero production volume. Adding these stricter criteria eliminates over
50% of the MINFILEs matched by minfile_producer_compilation. Because of higher selectively
MINFILEs in this layer are more likely to have prospective disposal sites.