Provide categorical exclusions from MEPA

This bill clarifies Montana's environmental review process by officially defining "categorical exclusions," which are actions state agencies can identify as having no significant environmental impact and therefore exempt from detailed environmental analysis. It directly affects state agencies by giving them the authority to determine which routine projects bypass the Montana Environmental Policy Act's requirements, reducing the need for courts to rely on federal definitions. The law includes a rebuttable presumption that these excluded actions do not require environmental impact statements, while also listing numerous existing exemptions such as building construction, historic preservation grants, and various natural resource activities. By codifying these exclusions, the bill aims to provide clearer guidance for decision-makers and the public while maintaining existing protections for specific agency functions.