The bill amends Section 82-4-231 of the Montana Code Annotated to revise the capacity requirements for siltation structures at strip and underground mines. It mandates that these siltation structures must be constructed with a design capacity that can detain water inflow or runoff from anticipated precipitation events, as well as average inflow from the underground mine, if applicable. The bill specifies that compliance is maintained even if the pond capacity is exceeded due to a series of small, consecutive storm events that cumulatively surpass the anticipated precipitation event.

Additionally, the bill introduces provisions for severability and contingent voidness, stating that if any part of the act is deemed invalid, the remaining valid parts will remain in effect. It also stipulates that if any provision is disapproved by the United States Secretary of the Interior, that portion will be void. The act is set to take effect immediately upon passage and approval.

Statutes affected:
LC Text: 82-4-231