R307-406-4. Adverse Impact

If the analysis required by R307-406-2 predicts that an adverse impact on visibility may reasonably be expected to occur in a mandatory Class I area, the director may require a proposed new major source or major modification to perform pre-construction and/or post-construction visibility monitoring in any mandatory Class I area as deemed necessary and appropriate to assess the impact of the proposed source or modification on visibility. Such monitoring shall be conducted in accordance with a monitoring plan prepared by the owner or operator of the source or his representative and approved by the director.