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The NRP had its beginnings in the late 1950's. Since that time, the program has grown to encompass a broad spectrum of scientific investigations. The sciences of hydrology, mathematics, chemistry, physics, ecology, biology, geology, and engineering are used to gain a fundamental understanding of the processes that affect the availability, movement, and quality of the Nation's water resources. Results of NRP's long-term research investigations often lead to the development of new concepts, techniques, and approaches that are applicable not only to the solution of current water problems, but also to future issues that may affect the Nation's water resources. Basic tools of hydrology that have been developed by the...
Categories: Project; Types: ScienceBase Project; Tags: Acid Mine Drainage, Aquatic Habitat, Arid Land Hydrology, Carbon Cycle, Contaminant Reactions and Transport, All tags...
Copiapite-group minerals of the general formula AR4(SO4)6(OH)2·nH2O, where A is predominantly Mg, Fe2+, or 0.67Al3+, R is predominantly Fe3+, and n is typically 20, are among several secondary hydrous Fe sulfates occurring in the inactive mine workings of the massive sulfide deposit at Iron Mountain, CA, a USEPA Superfund site that produces extremely acidic drainage. Samples of copiapite-group minerals, some with coexisting water, were collected from the Richmond mine. Approximately 200 mL of brownish pore water with a pH of −0.9 were extracted through centrifugation from a 10-L sample of moist copiapite-group minerals taken from pyritic muck piles. The pore water is extremely rich in ferric iron (Fe3+=149 g L−1,...
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On July 26, 2017, a solution containing approximately 200 kilograms of dissolved sodium bromide was added to the the flooded underground shaft of the Minnesota Mine, near Empire, Colorado. This addition was conducted as part of an effort to determine the degree to which the mine shaft is hydrologically connected to a series of downgradient seeps and springs. These seeps and springs discharge from the hillside and enter Lion Creek, an acidic, metal-rich stream that lies immediately to the west of the Minnesota Mine. A water quality sonde and pressure transducer deployed within the shaft recorded temperature, specific conductance, and stage before, during, and after the addition. The downgradient seeps and springs...
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Two synoptic sampling campaigns were conducted near Breckenridge, Colorado, to quantify metal loading to Illinois Gulch, a tributary of the Blue River. The first campaign, conducted in August 2016, was designed to determine the degree to which Illinois Gulch loses water to the underlying mine workings, and to determine the effect of these losses on observed metal loads. The second campaign, conducted in September 2017, was designed to evaluate metal loading within Iron Springs, a subwatershed that was responsible for the majority of the metal loading observed in 2016. A continuous, instream injection of a sodium bromide (NaBr) tracer was initiated at the head of the respective study reaches several days prior to...
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Rio Tinto, Spain, is an example of a fluvial system strongly influenced by acid rock and acid mine drainage. During the spring of 2018 and 2019, samples of stream waters and mine waters, biofilms, sediments and rocks, were collected in the field by Aubrey Zerkle. These samples were analyzed for comprehensive geochemistry, including Cr isotope geochemistry, anions and cations. Mineralogical analysis was conducted on powdered sediments and rocks.
Pre- and post-remediation data sets are used herein to assess the effectiveness of remedial measures implemented in the headwaters of the Mineral Creek watershed, where contamination from hard rock mining has led to elevated metal concentrations and acidic pH. Collection of pre- and post-remediation data sets generally followed the synoptic mass balance approach, in which numerous stream and inflow locations are sampled for the constituents of interest and estimates of streamflow are determined by tracer dilution. The comparison of pre- and post-remediation data sets is confounded by hydrologic effects and the effects of temporal variation. Hydrologic effects arise due to the relatively wet conditions that preceded...
Rainfall events cause both increases and decreases in acid and metals concentrations and their loadings from mine wastes, and unmined mineralized areas, into receiving streams based on data from 3 mines sites in the United States and other sites outside the US. Gradual increases in concentrations occur during long dry spells and sudden large increases are observed during the rising limb of the discharge following dry spells (first flush). By the time the discharge peak has occurred, concentrations are usually decreased, often to levels below those of pre-storm conditions and then they slowly rise again during the next dry spell. These dynamic changes in concentrations and loadings are related to the dissolution...
With the increased importance of water resources in the western United States and many areas worldwide, the remediation of impacts from historical mining becomes ever more important. A possible process of making decisions about remediation for a catchment might include identification of principal sources of metals in the catchment, classification of the sources as natural or anthropogenic, and simulations to evaluate different options for removal of anthropogenic sources. The application of this process is based on understanding the pre-mining conditions in the catchment, so that remediation goals appropriately correct for the impacts of mining. A field experiment in Redwell Basin, Colorado, provided a setting to...
I conduct field and laboratory research on processes affecting the distribution of inorganic constituents in natural waters. Most of my research focuses on redox sensitive compounds of arsenic, chromium, iron, sulfur, and mercury. I also study conductivity methods and applications for natural waters. Field sites have included the Summitville mine, CO, the Boulder Creek watershed, CO, the Mojave Desert, CA, the Questa mine, NM, and Yellowstone National Park.
The project focuses on the use of analytical techniques that we have developed to support a wide range of studies in water-rock interaction, integrating solid phase mineralogy and elemental chemistry and clay mineralogy into hydrologic and contaminant studies.
Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas River watershed have shown that cost-effective remediation of mine sites must be carefully planned. Of the more than 5400 mine, mill, and prospect sites in the watershed, Published in Understanding and Responding to Hazardous Substances at Mine Sites in the Western United States: Geological Society of America, Reviews in Engineering Geology, on pages 47 - 83, in 2007.
Aqueous chemical models have become popular tools for the interpretation of natural water chemistry. Unfortunately, these models have deficiencies because of (1) incorrect or inconsistent thermodynamic data, (2) invalid assumption regarding the equilibrium state, (3) inappropriate or invalidated corrections for nonideality, (4) inadequate expressions for temperature dependence, (5) invalidated limitations for ionic strength, composition and temperature, and (6) lack of data on solid solution solubility. The plethora of models and databases has prompted federal agencies, especially hazardous waste and nuclear waste managers, to request geochemical code validation. Acid mine waters are a major source of water pollution...
Pre- and post-remediation data sets are used herein to assess the effectiveness of remedial measures implemented in the headwaters of the Mineral Creek watershed, where contamination from hard rock mining has led to elevated metal concentrations and acidic pH. Collection of pre- and post-remediation data sets generally followed the synoptic mass balance approach, in which numerous stream and inflow locations are sampled for the constituents of interest and estimates of streamflow are determined by tracer dilution. The comparison of pre- and post-remediation data sets is confounded by hydrologic effects and the effects of temporal variation. Hydrologic effects arise due to the relatively wet conditions that preceded...
Abandoned mine land (AML) is one of the legacies of historic mining activities, causing a wide range of environmental problems worldwide. A stream monitoring study was conducted for a period of 7 years to evaluate the water quality trend in a Mid-Appalachian watershed, which was heavily impacted by past coal mining and subsequently reclaimed by reforestation and revegetation. GIS tools and multivariate statistical analyses were applied to characterize land cover, to assess temporal trends of the stream conditions, and to examine the linkages between water quality and land cover. In the entire watershed, 15.8% of the land was designated as AML reclaimed by reforestation (4.9%) and revegetation (10.8%). Statistic...
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Three synoptic sampling campaigns were conducted on upper Cement Creek, near Gladstone, Colorado, under low-flow conditions. The first campaign, conducted October 2012, was part of a larger campaign to characterize low-flow water quality in the entire Cement Creek watershed. The second campaign, conducted in September 2019, was designed to quantify metal loading and identify sources of contamination along a 2.5-kilometer study reach. The third campaign, conducted in September 2020, was designed to quantify loads and sources along the same 2.5-kilometer study reach during a test closure of a bulkhead on the Red and Bonita Mine, one of the primary sources of metals within the watershed. Streamflow measurements during...
    map background search result map search result map Minnesota Mine Shaft Tracer Data, Lion Creek Watershed near Empire, Colorado, July-November, 2017 Synoptic sampling data from Illinois Gulch and Iron Springs near Breckenridge, Colorado, August 2016 and September 2017 Synoptic sampling data from upper Cement Creek near Gladstone, Colorado, October 2012, September 2019, and September 2020 Geochemical data for waters, rocks, sediments and biofilms from Rio Tinto, Spain Minnesota Mine Shaft Tracer Data, Lion Creek Watershed near Empire, Colorado, July-November, 2017 Synoptic sampling data from upper Cement Creek near Gladstone, Colorado, October 2012, September 2019, and September 2020 Synoptic sampling data from Illinois Gulch and Iron Springs near Breckenridge, Colorado, August 2016 and September 2017 Geochemical data for waters, rocks, sediments and biofilms from Rio Tinto, Spain