Abstract
A legacy of waste rock associated with abandoned mining operations continues to degrade water quality in the Colorado Front Range. The success of remediation at these sites may be impeded by financial constraints, uncertain liability, and the legal status of lands in question. However, the development of safe, cost-effective reuses for orphan mine wastes may offset remediation costs and encourage stakeholder participation. Service-based, experiential education adds value to the effort, allowing undergraduate students to provide preliminary assessments of mine waste while interacting with nonprofit and consulting organizations. To investigate the feasibility of this approach, collaboration among the nonprofit Clear Creek Watershed Foundation, Colorado School of Mines, and Frontier Environmental Services, Inc., examined waste piles along Trail Creek, near Idaho Springs, CO. Piles were assessed for impact on the surrounding watershed and for potential reuse as foundational concrete aggregate for a proposed local wind farm. Grab samples and 30-subsample composites were evaluated according to established physical and chemical criteria. Physical data gathered included volumetric assessments of the piles, sieving to compare particle size distributions to ASTM aggregate standards, and ranking of each site according to distance to drainage, erosion, and vegetation present. Concentrations of metals regulated by EPA maximum contaminant levels (MCLs) were analyzed in leachates by ICP-AES and compared to regulatory limits. Slag material had sufficient coarse aggregate content for concrete applications (ASTM standards), while unprocessed waste rock, which comprised most of the material available, contained an excess of fines. Regarding chemical leachability, both waste rock and slag were found to be acceptable for landfill disposal with the exception of isolated lead measurements exceeding hazardous waste regulations. Over the investigated reach of Trail Creek, total metal loading increased by 4.8 kg/day proximal to the piles, suggesting that removal could alleviate the metal burden (particularly Zn and Cu) on receiving waters.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal American Society of Mining and Reclamation
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
