(a) For the purposes of addressing reasonably attributable visibility impairment, each State containing a mandatory Class I Federal area must include in the plan a strategy for evaluating reasonably attributable visibility impairment in any mandatory Class I Federal area by visual observation or other appropriate monitoring techniques. Such strategy must take into account current and anticipated visibility monitoring research, the availability of appropriate monitoring techniques, and such guidance as is provided by the Agency.
(b) The plan must provide for the consideration of available visibility data and must provide a mechanism for its use in decisions required by this subpart. [45 FR 80089, Dec. 2, 1980, as amended at 64 FR 35764, July 1, 1999]