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Dunn, J., Russell, C., & Morrissey, A. (1999). Remediating historic mine sites in Colorado. Min. Eng., 51(8), 32–35.
Abstract: This article provides examples of reclamation and remediation in Colorado watersheds. The projects were undertaken by the US Environmental Protection Agency (EPA) Region 8, in cooperation with the Colorado Division of Minerals and Geology (CDMG), Colorado Department of Public Health and Environment (CDPHE), US Forest Service (USFS), the Bureau of Land Management (BLM), Bureau of Reclamation (BOR) and the US Geological Survey (USGS). These agencies collaborated on the environmental problems at abandoned mines. These samples involved the interaction of surface and ground waters with sulfide-bearing rocks, mine workings and surface mine spoils that produce acid solutions charged with heavy metals that are toxic to organisms. In these examples, acid mine drainage from historic mines in Colorado has been approached cooperatively with stakeholders. Each example emphasizes one aspect of the three-stage process. These stages include characterization and prioritization, hydrologic controls and the evaluation of long-term remediation activities.
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Dillard, G. (2000). A win-win way to clean up by changing ionic state, new process can precipitate heavy metals. Pay Dirt, 734, 10–11.
Keywords: acid mine drainage; California; chemical composition; companies; environmental analysis; environmental management; heavy metals; ion exchange; ions; metal ores; metals; mining; pollutants; pollution; precipitation; processes; remediation; soils; surface water; United States; water treatment 22, Environmental geology
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Davies, G. J., Holmes, M., Wireman, M., King, K., Gertson, J. N., & Stefanic, J. M. (2001). Water tracing at scales of hours to decades as an aid to estimating hydraulic characteristics of the Leadville Mine drainage tunnel.
Abstract: The Leadville Mine Drainage Tunnel (LMDT) is a 3.3 kilometer structure that was constructed in the complicated geology of the Leadville mine district in the 1940's. Discharge from the LMDT is impacted by heavy metals and is treated at a plant built in 1992 operated by the United States Bureau of Reclamation. On the surface waste rock and other remnants of the mining operations litter the landscape and this material is exposed to precipitation. As a result of contact with this material, surface water often has pH of less than 3 and its containment and disposal is necessary before it impacts surface drainage and the nearby Arkansas River. Using a borehole drilled into the mine workings the U.S. EPA has devised a plan in which the impacted water is contained on the surface which then can be discharged into the mine workings to discharge from the LMDT and be treated. The percentage of water discharging from the mining district along the drainage tunnel is unknown, and since there is no access, information about the condition of the tunnel with regards to blockages is also relatively obscure. Application of quantitative water tracing using fluorescent dyes was used to model the flow parameters at the scale of hours in the tunnel and evaluate the likelihood of blockages. Because the tunnel has intersected several lithologies and faults, other locations such as discharging shafts, adits and surface streams that could be hydraulically connected to the LMDT were also monitored. An initial tracer experiment was done using an instantaneous injection, which was followed by additional injections of water. Another tracer injection was done when there was a continuous flow of impacted water into the workings. Analysis of the tracer concentration responses at water-filled shafts and at the portal were used to model the flow along the tunnel and estimate several hydraulic parameters. Waters in these settings are mixtures of components with different residence times, so, qualitative tritium data were used to evaluate residence times of decades. The combined injected tracer and tritium data as well as other geochemical data were used to infer the nature of flow and recharge into the tunnel.
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Becker, G., Wade, S., Riggins, J. D., Cullen, T. B., Venn, C., & Hallen, C. P. (2005). Effect of Bast Mine treatment discharge on Big Mine Run AMD and Mahanoy Creek in the Western Middle Anthracite Field of Pennsylvania.
Abstract: The Bast Mine (reopened in 2001) and Big Mine are two anthracite coal mines near Ashland, PA, that were abandoned in the 1930's and that are now causing drastic and opposite effects on the water quality of the streams originating from them. To quantify these effects, multiple samples were taken at 5 different sites: 3 along Big Mine Run and 2 from Mahanoy Creek (1 upstream and 1 downstream of the confluence with Big Mine Run). At each site, one set of the samples was treated with nitric acid for metals survey, one set was acidified with sulfuric acid for nitrate preservation, one set was filtered for sulfate and phosphate tests, and one set was unaltered. Measurements of pH, TDS, dissolved oxygen, and temperature were made in the field. Alkalinity, acidity, hardness, nitrates, orthophosphates and sulfates were analyzed using Hach procedures. Selected metals (Fe, Ni, Mg, Ca, Cu, Zn, Hg, Pb) were analyzed utilizing flame atomic absorption spectroscopy. Drainage from the Bast Mine is actively treated with hydrated lime before the water is piped down to Big Mine Run. pH and alkalinity values were much higher at the outflow compared to those in the water with which it merged. The two waters could be visibly distinguished some distance downstream. pH values decreased, sulfate and dissolved iron increased and alkalinity was reduced to zero until the confluence with Mahanoy Creek. The high alkalinity, turbidity, TDS and calcium values in Mahanoy Creek were somewhat reduced downstream of the confluence with the much lower discharge Big Mine Run.
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Al-Abed, S., Allen, D., Bates, E., & Reisman, D. (2002). Lime treatment lagoons technology for treating acid mine drainage from two mining sites.
Keywords: acid mine drainage; case studies; Copper Mine; drainage; geochemistry; heavy metals; hydrochemistry; Leviathan Mine; mining; Nevada; pH; pollutants; pollution; precipitation; remediation; runoff; surface water; Tennessee; United States; waste lagoons; water treatment 22 Environmental geology; 02B Hydrochemistry
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