Colo. Rev. Stat. § 34-32-121.5
Any person engaged in a mining operation shall notify the office of any failure or imminent failure as soon as reasonably practicable after such person has knowledge of such condition, but for in situ leach mining operations in no event more than twenty-four hours after the discovery of such failure or an imminent failure, of: Any impoundment, embankment, or slope that poses a reasonable potential for danger to any persons or property or to the environment; any structure for in situ leach mining operations designed to detect, prevent, minimize, or mitigate adverse impacts on groundwater; any structure used in connection with in situ leach mining designed to detect, prevent, minimize, or mitigate adverse impacts on human health, wildlife, or the environment; or any environmental protection facility designed to contain or control chemicals or waste that are acid- or toxic-forming, as identified in the permit.
C.R.S. § 34-32-121.5