The Environmental Improvement Board amended N.M. Code §20.2.81 to conform those rules to federal requirements for regional haze. The plan establishes requirements for state rules to meet the requirements of 40 C.F.R. §51.309, including a determination of best available retrofit technology for nitrogen oxides. Changes took effect July 6, 2011. http://www.nmcpr.state.nm.us/nmregister/xxii/xxii12/20.2.81amend.htm.