SB365

Montana SB365 revises siltation structure capacity requirements at mines.

Montana SB365 revises the capacity requirements for siltation structures at strip mines and underground mines. The bill mandates that siltation structures must be designed to detain water inflow or runoff from an anticipated precipitation event plus the average inflow from the underground mine. The structures must be constructed with a specified design capacity to ensure compliance. The bill also outlines various operational and reclamation requirements for mining activities, including measures to prevent land subsidence, avoid channel deepening, and preserve hydrologic functions.