Generally revise water supply requirements for coal-fired generating units

This bill requires operators of coal-fired power plants in Montana to ensure permanent access to water for nearby cities and towns, even if the plant closes or retires. It mandates that operators maintain water conveyance systems until environmental contamination from the plant or its waste storage areas meets state cleanup standards. The legislation also updates legal definitions to clarify what constitutes "affected property" and "remediation" while establishing clearer financial assurance requirements for cleanup obligations. These changes directly impact coal plant operators and local municipalities by creating enforceable water supply protections and refining how cleanup responsibilities are defined and managed.