N.M. Admin. Code § 19.8.20.2003
When no longer needed for monitoring or other use approved by the director upon a finding of no adverse environmental or health and safety effects, or unless approved for transfer as a water well under 19.8.20.2021 NMAC, each exploration hole, other drilled hole or borehole, well, and other exposed underground openings such as shafts, drifts, adits, tunnels or entryways shall be capped, sealed, backfilled, or otherwise properly managed, as required by the director, under 19.8.20.2001 NMAC and consistent with 30 CFR 75.1711. Permanent closure measures shall be designed to prevent access to the mine workings by people, livestock, fish and wildlife, and machinery, and to keep acid or other toxic drainage from entering ground or surface waters.
N.M. Admin. Code § 19.8.20.2003