Committee backs measure letting mines exceed detention capacity during extreme storms if operators restore capacity

The House Natural Resources Committee voted to recommend concurrence on Senate Bill 365, which clarifies compliance expectations for siltation and detention ponds at mine sites during extreme weather.

Sen. Barry Usher, sponsor in opening remarks, said increasingly frequent storms followed by wet ground conditions have made it difficult for operators to dewater detention basins quickly. He and industry witnesses told the committee that when ponds overflow during a major storm event, operators should not automatically be declared out of compliance if the facility was built to the applicable design specifications and the operator is working to restore capacity as weather permits.

Darryl James, representing Westmoreland Mining (owner/operator of the Rosebud Mine at Colstrip), explained that increasing basin size indefinitely is impractical for cost and downstream-flow reasons. He and other proponents, including the Montana Coal Council and the Billings Chamber of Commerce, said the bill keeps water-quality responsibilities in place and requires operators to undertake timely measures to restore capacity.

The bill was amended in the Senate to require an operator to restore capacity “as soon as weather and ground conditions permit,” language proponents said maintains an incentive to promptly address pond filling. Dan Walsh, Air, Energy and Mining Division administrator at DEQ, appeared as an informational witness and was available for committee questions. No opponents testified in the committee hearing. Vice Chair Oblander moved that the committee concur; the motion passed on a voice vote with proxies recorded. The committee’s concurrence moves the bill to the House floor.