N.M. Code R. § 20.2.7.115
The department may issue a determination regarding an owner or operator's assertion of the affirmative defense under Section 111, 112, or 113 of 20.2.7 NMAC on the basis of any relevant information, including but not limited to information submitted pursuant to this part or obtained through an inspection. Any such determination is not a final action and is not reviewable, shall not be a prerequisite to the commencement of an administrative or judicial enforcement action, does not constitute a waiver of liability pursuant to Section 116 of 20.2.7 NMAC, and shall not preclude an enforcement action by the federal government or a citizen pursuant to the federal Clean Air Act. A source may not assert an affirmative defense under Section 111, 112, or 113 of 20.2.7 NMAC in an administrative or judicial enforcement action unless it asserted such defense pursuant to Subsection B of 20.2.7.110 NMAC.
N.M. Code R. § 20.2.7.115