17.8.1110    VISIBILITY MONITORING

(1) The owner or operator of a proposed major stationary source or major modification shall submit with the application an analysis of existing visibility in or immediately adjacent to the federal Class I area potentially impacted by the proposed project. The validity of the analysis shall be determined by the department.

(2) As necessary to establish visibility conditions within the mandatory Class I area prior to construction and operation of the source or modification, the analysis shall include a collection of continuous visibility monitoring data. Such data shall relate to and shall have been gathered over the year preceding receipt of the complete application, except that if the department determines that a complete and adequate analysis can be accomplished with monitoring data gathered over a period shorter than one year, the data that is required must have been gathered over at least that shorter period. Where applicable, the owner or operator may demonstrate that existing visibility monitoring data may be sufficient.

(3) Pursuant to the requirements of this subchapter, the owner or operator of the source shall submit a preconstruction visibility monitoring plan prior to the filing of a permit application. Within 30 days, the department must, after consultation with the affected federal land manager, review and either approve the monitoring program or specify the changes necessary for approval. If the department fails to act within the 30 days, the monitoring program shall be deemed approved.

(4) The owner or operator of a proposed major stationary source or major modification, after construction has been completed, shall conduct such visibility monitoring as the department may require as a permit condition to establish the effect the source has on visibility conditions within the mandatory Class I area being impacted.

(5) The department may waive the requirements of (1), (2), and (3) if the value of "V" in the equation below is less than 0.50 or, if for any other reason which can be demonstrated to the satisfaction of the department, an analysis of visibility is not necessary.

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��������������������V��������=��������(Emissions)^1/2�����������������Distance

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�������where: Emissions = emissions from the major stationary source or modification

������������������������������������������of nitrogen oxides, particulate matter, or sulfur dioxide, whichever

������������������������������������������is highest, in tons per year.

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��������������������Distance =�� distance, in kilometers, from the proposed major stationary source or

������������������������������������������major modification to each federal Class I area.

History: 75-2-111, 75-2-203, MCA; IMP, 75-2-203, 75-2-204, MCA; NEW, 1985 MAR p. 1326, Eff. 9/13/85; AMD, 1988 MAR p. 826, Eff. 4/29/88; TRANS, from DHES, 1996 MAR p. 2285.