Background:
On September 2, 2024, an On-Scene Coordinator (OSC) and contractors from the Emergency Management Branch (EMB) mobilized to conduct an emergency response to the Bonita Peak Mining District (BPMD) and the Anglo Saxon Mine Site. The response was focused on addressing the failure of an historic crib wall retaining mining waste rock and tailings at the edge of County Road 110 between Silverton, CO and Gladstone, CO. The crib wall partially collapsed on August 25, 2024, due to excessive precipitation and decaying timbers, and was blocking part of the roadway. The collapsed wall and mining wastes were also encroaching on a nearby drainage culvert that conveyed diverted mineralized water from draining a nearby adit. San Juan County was concerned about the potential for additional collapse blocking the road, plugging the culvert, or impacting nearby Cement Creek, a tributary to the Animas River. The objectives of the response were to clear debris and mine wastes from the roadway, remove the remaining crib wall, relocate waste rock and tailings to the nearby Anglo Saxon repository, protect the culvert and adit flow path, and stabilize the native material on the hillside to prevent erosion or slope failures. This work was completed on September 8, 2024. Remedial Branch will transfer Superfund resources from the BPMD site funding to cover the cost of this response action and will continue working with CDPHE and DRMS on post-removal site controls and other activites, as outlined in the interim ROD and associated work plans.
