Project

Herrera led the effort to develop planning documents and conduct site inspections to characterize the Black Pine Mine site for Montana Department of Environmental Quality under an ASARCO settlement with the state of Montana for $17.5 million dollars. The site includes 1,000 acres of patented mining claims and 157 unpatented lode claims on lands administered by the United States Forest Service. The range of mining impacted lands includes tailings impoundments, waste rock piles, mine audits and shafts, and fluvially deposited mine tailings and mill deposits. The Site Investigation characterized waste onsite, and the data collected was analyzed for impacts to human health and the ecology and contaminants of concern were developed.  An alternatives evaluation of reclamation options was performed and a preferred alternative was identified and presented to the public. The preferred alternative included the removal of approximately 400,000 cubic yards of mine waste from waste rock piles, tailings impoundments, and dispersed tailings in the floodplain and placing them in an onsite repository.  The excavated areas will be regraded and a reach of South Fork Lower Willow Creek will be reconnected with the floodplain following the removal of tailings from the tailings impoundments.  Additionally a tributary to South Fork Lower Willow Creek will be restored to its natural alignment. A natural regrade design for the repository was developed so the repository would blend in the surrounding landscape. Herrera led the geotechnical investigation of the repository location and assisted with the development of bid packages for the multi-phased reclamation project.  The excavation of the repository occurred in the summer of 2015 with Herrera providing construction oversight.  The site reclamation bid package was released for bid in the fall of 2015 and Herrera assisted with the design and bid process and performed construction oversight during the 2016 construction season. Construction of the site reclamation is scheduled to be completed in 2017 and Herrera will perform construction oversight as well as project closeout documentation.