Bill > SB365

This bill revises the requirements for siltation structures at strip mines and underground mines in Montana. Specifically, the bill modifies existing law to require that siltation structures (which are ponds or basins designed to collect sediment from mine runoff) be constructed with a design capacity specified in administrative rules to detain water inflow or runoff from an anticipated precipitation event, plus any average inflow from the underground mine. Notably, the bill provides that a siltation structure will be considered compliant even if its capacity is exceeded during a series of small, consecutive storm events, as long as the operator actively works to restore pond capacity when weather and ground conditions permit. The bill also includes provisions for severability (meaning if one part of the act is found invalid, the rest can remain in effect) and a contingent voidness clause that would nullify the act if it is disapproved by the U.S. Secretary of the Interior. The bill is effective immediately upon passage and approval, and it aims to provide more flexibility for mine operators in managing water runoff and sediment collection while maintaining environmental protections.

Agriculture and Natural Resources

https://bills.legmt.gov/#/laws/bill/2/LC1508