Indiana Geological Survey

Permanent link for this communityhttps://hdl.handle.net/2022/154

The Indiana Geological and Water Survey (IGWS) is a long-standing, state-supported organization benefiting the welfare of the citizens of Indiana since Dr. David Dale Owen was hired to conduct a geological assessment of the state during 1837 and 1838. For most of the 20th century, the IGWS was associated with Indiana University (IU), and in 1993, Indiana statute (IC 21-47-2) formally established the IGWS as part of the university. The IGWS director serves as the state geologist of Indiana. Under the direction of the state geologist, the survey is charged with conducting geological research, providing geological information, data and educational outreach, and maintaining physical and digital geological collections.

https://igws.indiana.edu/

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Browsing Indiana Geological Survey by Subject "acid mine drainage"

Now showing 1 - 7 of 7
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    Assessment of Two Field-Scale Sulfate-Reducing Bioreactors Using Sulfur Isotopes
    (2010-06) Reeder, M.D.; Branam, T.D.; Olyphant, G.A.
    Sulfate-reducing bioreactors (SRBRs) have shown promise as a cost-effective option in the passive remediation of acid mine drainage (AMD). While these systems do provide the necessary conditions for increased bacterial activity, little is known about the internal dynamics and the functional lifespan of the systems in field settings. To help address these issues, two field-scale bioreactors are being monitored using an array of sampling ports distributed at varying depths throughout the treatment cells. These internal monitoring ports are located in such a way as to observe 3-D trends in activity occurring within the system. Water samples collected from the ports, as well as samples from the AMD inflow and outflow, have been analyzed for δ34S of sulfate as well as standard chemical parameters. Preliminary results indicate that in both systems, bacterial sulfate reduction is occurring yet the degree of reduction is not uniform throughout the cells. Within each system, areas where only a limited amount of bacterial sulfate reduction has occurred are characterized by high concentrations of sulfate coupled with δ34S values only slightly different than the influent AMD. In contrast, low sulfate concentrations together with large δ34S fractionations are found in areas where extensive bacterial sulfate reduction has taken place. The observed range in fractionation values likely reflects the development of preferential flow paths and points of stagnation within the systems. This implies that not all of the reactive substrate put into a cell will contribute to AMD treatment. The results of this study provide information not typically attainable in smaller laboratory-scale studies and point to the need for further engineering of SRBRs to optimize field-scale applications.
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    Challenges of Coal-Mine Reclamation in Indiana
    (2010-03-11) Harper, Denver; Branam, Tracy
    Since the nineteenth century, more than 2.2 billion metric tons (2.4 billion short tons) of coal have been extracted from underground and surface mines of Indiana, directly affecting approximately 2,000 square kilometers (770 square miles) of southwestern Indiana. In addition, coal-preparation facilities have produced deposits of pyritic refuse materials that extend across more than 2,400 hectares (6,000 acres). Some of the environmental effects of these very large-scale activities—particularly those conducted before passage of the Surface Mining Control and Reclamation Act of 1977—include land subsidence, erosion, stream siltation, acidic mine drainage, and groundwater contamination. A great variety of field-scale engineering, chemical, biological, and ecological techniques have been developed and implemented over a period of decades to address these problems, and research is ongoing. The potential also exists for development of geothermal resources related to groundwater in flooded underground mines, representing a high-yield aquifer that contains as much as 640 billion liters (170 billion gallons) of water.
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    Controls on pH and Pyrite Oxidation Pathways across the Phreatic Surface of a Coal Waste Deposit in Southwest Indiana
    (2010-06) Hardisty, D.S.; Olyphant, G.A.; Pratt, L.M.
    During acid mine drainage (AMD) generation, the factors controlling pH and pyrite oxidation can differ between the saturated and unsaturated zones. These differences, however, may not always be considered during field-scale remediation efforts. At an unreclaimed coal waste deposit in southwest Indiana, preliminary studies have identified a horizontal pH gradient that increases from 2.8 to 6.5 along a 90 meter shallow groundwater flow path. This site provides a unique opportunity to determine pyrite oxidation pathways under varying conditions within both the saturated and unsaturated zones of coal mine refuse being subjected to weathering processes. Vertical profiles of pore-water were obtained using Diffusion-Controlled Dialysis Membrane Samplers installed across the phreatic surface. Samples were collected at 2 cm intervals from the ground surface to a depth of 40 cm with the bottom 10 cm being fully saturated. Samples collected during the summer reveal a linear trend with respect to pH and depth with pH values of approximately 2.5 near the surface to 3.4 at the base of the profile. Concentrations of sulfate (SO42-) and iron (Fe-total) during the summer are highest near the surface and in the case of Fe, decrease by an order of magnitude at the bottom of the profile. Samples collected during the autumn show that within the saturated zone, ferrous iron (Fe2+) concentrations are elevated relative to ferric iron (Fe3+), but Fe3+ increases with decreasing pH. This indicates that atmospheric oxygen is the limiting factor in pyrite oxidation both through direct oxidation of pyrite and through the oxidation of Fe2+ to Fe3+ that can then oxidize pyrite in both saturated and unsaturated conditions at lower pH values. These results imply that an increase in the thickness of the saturated zone can act as a control on acidity generation by preventing positive feedback cycling of Fe3+ to oxidize pyrite.
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    Effects of passive reclamation on water quality in the northeastern drainage of Augusta Lake, Pike County, Indiana
    (2006-11-20) Comer, J. B.; Smith, R. T.; Ennis, M. V.; Branam, T. D.; Welp, L. R.; Simon, T. P.
    Augusta Lake is a 33-acre man-made lake located on Mill Creek, a tributary of the Patoka River in the coal mining region of south-central Pike County, Indiana. The lake is strongly acidic (pH = 3.1-4.4) and mostly barren, receiving acidic inflows from a 1.5-square-mile drainage area, 60 percent of which consists of abandoned coal mines. The dominant source of acidity, sulfate, and metals is in the northeastern drainage area where acidic water seeps from mine spoil. An array of wetlands, anoxic limestone drains, and successive alkaline-producing systems (SAPS) was emplaced to treat this area. Beginning in 1997, water quality was monitored for 2 years at eight sites to evaluate the effectiveness of this passive reclamation strategy. The pH of water at all sites, other than the discharge from the SAPS and where surface water and SAPS outflow mix, remained acidic throughout the monitoring period. Acidity and pH varied seasonally at four sites, and pH was lowest and acidity highest during the months from late spring to early fall. Although Augusta Lake remained strongly acidic, outflows contained significantly reduced metals concentrations, indicating that natural processes operating in the lake remove metals from solution. Water flowing northward from the lake along Mill Creek rapidly approaches pH neutrality through natural reactions with the bedrock and sediments, and downstream reaches support aquatic life. Although Augusta Lake may not be suitable for recreational uses, it does serve the important function of cleaning dissolved metals from mine effluent.
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    Groundwater Flow Modeling of an Abandoned Mine Lands Site Scheduled for Reclamation
    (2010-06) Waddle, Robert C.; Olyphant, Greg A
    Groundwater flow models represent one tool that can be used in evaluating the hydrologic conditions of abandoned mine land (AML) sites, and they can be used to preview the probable hydrologic outcomes of reclamation designs. A three-dimensional, variably saturated groundwater flow model was used to characterize the hydrology of a 47 ha AML site in southwestern Indiana. Of particular concern was the flow field extending through a tailings deposit to a large seep contributing acid mine drainage to the local stream. The model was then used to evaluate a potential reclamation plan that would redirect the acidic flow into an onsite lowland area for passive treatment. A transient model was calibrated by adjusting the model parameters until a minimum residual was achieved between simulated and observed water table elevations in 6 observation wells over a time period of 50 days. The best-fit model had a root mean squared error (RMSE) of 0.195 m. Modeling results show that the seep is fed from a ground watershed of approximately 7.7 ha which spans across the tailings into the coarse-grained refuse bordering the deposit. Further results show that minor alterations of surface topography within the tailings deposit could potentially redirect and contain the acidic groundwater on site for passive treatment prior to discharging into the local drainage network. This study demonstrates the utility of using groundwater flow models to preview hydrologic conditions at AML sites and to anticipate the results of reclamation alternatives.
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    Mapping the Variability of Groundwater Quality in an Abandoned Tailings Deposit using Electromagnetic Geophysical Techniques
    (2010-06) Gore, D. Alex; Olyphant, G.A.
    A geophysical study was conducted at an abandoned coal mine site in southwestern Indiana in an effort to characterize the spatial variability of groundwater quality and to identify areas that contain high concentrations of total dissolved solids (TDS) and other indicators of acid mine drainage. The study utilized an EM34-3 terrain conductivity instrument to measure the apparent electrical conductivity of the underlying earth. Terrain conductivity is routinely attributed to the electrical conductivity of the underlying material, porosity, moisture content, and the dissolved electrolytes in pore fluid. To interpret the instrument response, terrain conductivity data were compared to field and laboratory chemistry of water samples collected from 27 monitoring wells. Terrain conductivity values ranged from 17-58 millisiemens/meter over the extent of the study area which included mine refuse, levee material, and natural soils. The contribution of pore water chemistry to the overall terrain conductivity was analyzed by measuring the specific conductance (SpC) of ground water samples which is a reflection of the concentration of TDS. The specific conductance ranged from 1380-5410µmhos/cm at 25° C; where the higher SpC values correspond to a higher concentration of TDS due to pyrite dissolution. A map of the terrain conductivity values indicated that high conductivity values were concentrated in specific areas which will need special attention in remediation plans. The mapping also indicated that the majority of the site contains groundwater with a low SpC and should be amenable to less intensive remediation. A map of the contamination plume based on terrain conductivity values was consistent with a groundwater flow model constructed for this site. A correlation was also observed between subsurface hydraulic conductivity and terrain conductivity measurements (R2=0.66) indicating an instrument response to soil permeability. This study indicates that shallow electrical geophysical exploration can be used to locate groundwater contamination plumes when subsurface hydraulic properties are taken into account.
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    Toxic Metals Removal in Acid Mine Drainage Treatment Wetlands
    (Indiana Geological Survey, 2001) Smith, Ronald T.; Comer, John B.; Ennis, Margaret V.; Branam, Tracy D.; Butler, Sarah M.; Renton, Patricia M.
    The removal of trace metals from acid mine drainage was studied in four constructed wetlands on abandoned mine lands in southwestern Indiana. The wetlands vary in the constraints of their settings, their design, the materials used in their construction, and their effectiveness at removing metals. Aqueous and sediment samples were collected twice a year at each of sixteen sampling locations. Water, pore water, and sediment extracts were analyzed for their physicochemical characteristics, major ions, and the trace metals arsenic, beryllium, boron, cadmium, chromium, copper, lead, molybdenum, nickel, selenium, and vanadium. A simplified sequential extraction was used to distinguish between bio-available and residual metals. The relative distributions of metals between the bio-available and residual fractions were compared with one another in order to determine the factors which control precipitation, sorption, and mineralization of trace metals, and assess their potential mobility. Data representing late winter and late summer conditions were compared to identify seasonal differences in metals concentrations in the various wetland cells. The overall percentage of major metals removed from the AMD was determined. The Aquachem computer program was used to generate a diagram of the prevalent chemical character of the wetlands waters and to introduce data to a water chemistry modeling program, PhreeqC. The PhreeqC program determined saturation indices for mineral phases in water entering and leaving the wetlands. The water and sediment metals values were compared with published criteria for water and sediment quality.