Governing Law and Regulations
Montana Department of Environmental Quality (DEQ) Permitting and Compliance Division Air Resources Management Bureau
U.S. Environmental Protection Agency Region 8
See national section for basic information and federal regulations.
Comparison: State vs. Federal
• Rules. Montana requires any new or modified source of air contaminants to secure an air quality permit to construct, unless specifically excluded. New major sources or modifications to existing major sources must comply with the applicable provisions of nonattainment New Source Review (NSR) and/or Prevention of Significant Deterioration (PSD) depending on the attainment status of the area where the source is located and the type and quantity of air pollutants emitted.
Montana currently has several counties that are in nonattainment with one or more of the National Ambient Air Quality Standards (NAAQS). The provisions of nonattainment NSR apply to new major sources or major modifications in those areas, while PSD requirements apply to attainment areas. Montana ...