The Colorado Supreme Court held that Summit County’s ban on the use of cyanide or other toxic chemicals in certain mining operations for all zoning districts in the county is impliedly preempted by the State Mined Land Reclamation act (MLRA), amended in 1993 to give the State Mined Land Reclamation Board (Board) authority over the use of these chemicals. The Court determined that the amended statute gave the Board extensive authority to authorize and regulate the use of such chemicals under the terms of an Environmental Protection Plan for each operation. The Court concluded that the County’s ordinance “is not a proper exercise of its land use authority because it excludes what the General Assembly has authorized.” The Court noted that although express preemption did not apply since the Act recognizes legitimate exercise of Counties’ land use authority, such authority is not without bounds. The Court cited the following three reasons for its conclusion of implied preemption: “(1) the ordinance impedes the MLRA’s goal of encouraging mineral development while protecting human health and the environment; (2) the ordinance is inconsistent with both the General Assembly’s decision to authorize mining operations that use chemicals for extraction and the resulting Board-regulated permitting regime for Designated Mining Operations; and (3) state statutes and cannons of statutory construction require that we resolve the conflict between the MLRA and Summit County’s ban ordinance in favor of the MLRA.” Lastly, the Court explained that “Implied preemption occurred here because the General Assembly expressed a sufficiently dominant interest by assigning to the Board the field of the use of chemicals and other toxic and acidic reagents in mining operations for mineral processing.”
Colorado Mining Association v. Board of County Commissioners of Summit County, 2009 WL 60506 (Colo. 1/12/2009).
The opinion can be accessed at: http://www.cobar.org/opinions/opinion.cfm?opinionid=6969&courtid=2
