This Site was the subject of a Removal Action in 2014, where the State of Colorado rehabilitated a length of tunnel and EPA installed a bulkhead (also referred to as a plug in some documents).
In the fall of 2020, the Colorado Department of Reclamation and Mine Safety (DRMS) approached EPA for some repairs to the bulkhead pressure monitoring system. Specifically, the pressure gauge was under substantial pressure ~360 psi - and was showing very early signs of failure. The gauge had been installed during the removal action, and lacked proper isolation controls to service the gauge.
Construction plans have been developed to replace the gauge and reconfigure the bulkhead piping, and have undergone review and concurrence from the U.S. Army Corps of Engineers. Repairs were completed in May 2022.
A link to the original removal action webpage is provided in the Links section.