EPA contractors failed to beat back claims by states, private property owners, and the Navajo Nation over the 2015 Gold King mine spill allegedly triggered by their negligence.

New Mexico, Utah, and the Navajo Nation may go forward with their Superfund claims against the contractors as facility operators, arrangers for disposal of hazardous waste, and waste transporters, the U.S. District Court for the District of New Mexico said March 20.

The contractors, Weston Solutions Inc. and Environmental Restoration LLC, aren’t immune from suit under the government contractor defense.

They failed to show the government provided reasonably precise specifications, that the...