Evaluation of Airborne Thermal Infrared Imagery for Locating Mine Drainage Sites in the Lower Kettle Creek and Cooks Run Basins,Pennsylvania, USA

Abstract.  High-resolution airborne thermal infrared (TIR) imagery data were collected over 90.6 km² (35 mi²) of remote and rugged terrain in the Kettle Creek and Cooks Run Basins, tributaries of the West Branch of the Susquehanna River in north-central Pennsylvania. The purpose of this investigation was to evaluate the effectiveness of TIR for identifying sources of acid mine drainage (AMD) associated with abandoned coal mines. Coal mining from the late 1800s resulted in many AMD sources from abandoned mines in the area. However, very little detailed mine information was available, particularly on the source locations of AMD sites. Potential AMD sources were extracted from airborne TIR data employing custom image processing algorithms and GIS data analysis. Based on field reconnaissance of 103 TIR anomalies, 53 sites (51%) were classified as AMD. The AMD sources had low pH (<4) and elevated concentrations of iron and aluminum. Of the 53 sites, approximately 26 sites could be correlated with sites previously documented as AMD. The other 27 mine discharges identified in the TIR data were previously undocumented. This paper presents a summary of the procedures used to process the TIR data and extract potential mine drainage sites, methods used for field reconnaissance and verification of TIR data, and a brief summary of water-quality data.     

What Limits the Productivity of Acid Mine Drainage Treatment Ponds?

Abstract.  Acid mine drainage (AMD) treatment ponds are very common in the U.S. Appalachian coal region and are the main source of many headwater streams. Though the water that discharges from these ponds generally meets state and federal water quality standards, there is a distinct lack of productivity in most of these ponds. Our first objective was to compare the productivity of chemically-treated, biologically-treated, and untreated AMD ponds with uncontaminated (reference) ponds. Next, we used principal component analysis and multiple regression of 20 physicochemical characteristics of these ponds to resolve which factor(s) were responsible for inhibiting productivity. We discovered that chemically-treated AMD ponds and untreated AMD ponds exhibited significantly less gross primary productivity (GPP) than reference ponds; biologically-treated ponds (containing AMD that has passed through a wetland) did not vary significantly from reference ponds. Chemically-treated ponds also had significantly less net primary productivity (NPP) than reference ponds. Community respiration did not vary among the pond types. Our test results indicated that soluble reactive phosphate concentration explained most of the variance in both GPP and NPP. Apparently, phosphate availability, not metal toxicity, regulated phytoplankton productivity in these ponds.     

Geochemical and Stable Isotope Evidence for Precipitation and Groundwater Sourcing of Recharge at the Green Valley Site,Vigo County,Indiana

Abstract  We examined the recharge sources of acid mine drainage (AMD) seeps that form at the toe of the coal refuse (gob) pile at a site in Indiana, using traditional geochemistry and oxygen isotopes. AMD from this site has impacted local waterways, and reducing the volume of AMD is a priority. Our observations indicate that there are two main sources of recharge. The first is relatively dilute, isotopically homogenous, geochemically-reducing groundwater that flows up through pre-mining karst-like features beneath the gob pile due to localized, precipitation-induced, hydraulic head. This produces a perched water table above the regional water table. The second source of recharge is oxidizing and isotopically variable meteoric precipitation that percolates through the permeable capping material; a partially buried and abandoned railroad grade may also channel meteoric waters into the pile. During periods of low precipitation, oxygenated pore moisture in the unsaturated zone facilitates AMD generation. During periods of elevated precipitation, these metal-rich pore fluids are flushed through the system by isotopically variable, oxygenated, metal-poor meteoric waters. Each source contributes subequal but variable amounts of recharge waters. The hydraulic conductivity and permeability of the gob pile, as calculated by isotopic lag, is consistent with values for silty to clean unconsolidated sand.Electronic Supplementary Material  Electronic Supplementary Material is available for this article if you access it at     

The Use of Measured and Calculated Acidity Values to Improve the Quality of Mine Drainage Datasets

Abstract:  The net acidity of a water sample can be measured directly by titration with a standardized base solution or calculated from the measured concentrations of the acidic and basic components. For coal mine drainage, the acidic components are primarily accounted for by free protons and dissolved Fe²⁺, Fe³⁺, Al³⁺, and Mn²⁺. The base component is primarily accounted for by bicarbonate. A standard way to calculate the acidity for coal mine drainage is: Acid^calc = 50*(2*Fe²⁺/56 + 3*Fe³⁺/56 + 3*Al/27 + 2*Mn/55 + 1000*10^-pH)—alkalinity, where acidity and alkalinity are measured as mg/L CaCO₃ and the metals are mg/L. Because such methods of estimating acidity are derived by independent laboratory procedures, their comparison can provide a valuable QA/QC for AMD datasets. The relationship between measured and calculated acidities was evaluated for 14 datasets of samples collected from mine drainage discharges, polluted receiving streams, or passive treatment systems, containing a total of 1,484 sample analyses. The datasets were variable in nature, ranging from watersheds where most of the discharges contained alkalinity to ones where all of the discharges were acidic. Good relationships were found to exist between measured and calculated acidities. The average acidity measurement was 239 mg/L CaCO₃ and the average acidity calculation was 226 mg/L CaCO₃. Linear regressions were calculated for individual datasets and for the entire dataset. The linear regression for the entire dataset was: Acid^calc = 0.98 * Acid^meas – 8, r² = 0.98. The good correlation between calculated and measured acidity is the basis for an easy and inexpensive QA/QC for AMD data. Substantial variation between measured and calculated acidities can be used to infer sampling or analytical problems.     

Resistivity Level Runs to Detect Water-filled Mine Voids between Drill Holes

Abstract.  Resistivity level runs are collected by lowering a current source down one well and measuring the resulting voltage at the same depth in another well. Mine voids between the wells that contain acid water appear as conductive anomalies on the resulting apparent resistivity profiles. Resistivity level runs can be collected rapidly and without lowering expensive equipment down holes of unknown stability. The data can be interpreted on-site, and are relatively insensitive to positioning errors. The method is well suited to sites where several drill holes have failed to intersect a known mine void. We demonstrated the feasibility of resistivity level run profiling at an abandoned mine complex in central Pennsylvania, where resistivity level runs were successfully used to locate haulage ways containing mine water.     

The Influence of Coal Quality Variation on Utilization of Water from Abandoned Coal Mines as a Municipal Water Source

Abstract.   As population increases and high quality water becomes more difficult to obtain, many communities will seek alternative water supply sources. Some municipalities have realized that they have a reservoir of unexploited water readily available in abandoned underground coal mines. Analysis of the mines history, the quality of the coal and water that reside within the mine, and knowledge of local hydrology, geology, and mine chemistry will provide communities with the information they need to determine the best mine sites to use.     

Performance of Three Aquatic Plant Species in Bench-scale Acid Mine Drainage Wetland Test Cells

Abstract  We investigated pollutant removal from acid mine drainage (AMD) by three different aquatic plant species (Typha angustifolia, Desmostachya bipinnata, and Sacharum bengalense) in bench-scale wetland test cells of 1 m³. AMD was generated in the laboratory using chalcopyrite, galena, and sphalerite ore. A substrate containing 75% soil, 20% powdered goat manure, and 5% wood shavings was used in each cell. The performance of the system was evaluated for different water column heights (100, 150, and 200 mm) and for different retention periods (24, 48, 72, 96, and 168 hrs). The performance of the plant species was different for the various metals of AMD; therefore, multi-species plantings should be considered in constructed wetlands.     

Underground Mine Water for Heating and Cooling using Geothermal Heat Pump Systems

Abstract  In many regions of the world, flooded mines are a potentially cost-effective option for heating and cooling using geothermal heat pump systems. For example, a single coal seam in Pennsylvania, West Virginia, and Ohio contains 5.1 x 10¹² L of water. The growing volume of water discharging from this one coal seam totals 380,000 L/min, which could theoretically heat and cool 20,000 homes. Using the water stored in the mines would conservatively extend this option to an order of magnitude more sites. Based on current energy prices, geothermal heat pump systems using mine water could reduce annual costs for heating by 67% and cooling by 50% over conventional methods (natural gas or heating oil and standard air conditioning).     

Optimizing the Effluent Treatment at a Coal Mine by Process Modelling

Abstract:   The water network of a coal mine was audited and simulated by an interactive steady state model and the results were used to optimise the mines water management strategy. Simulation of the interactions showed that calcium carbonate powder could be used as an alternative to lime for neutralization of acid water at a reagent cost saving of 56%. Gypsum crystallization would reduce sulphate concentrations in the neutralization plant by 30% and in the coal processing plant by 60%. The capital cost for a neutralization/gypsum crystallization plant for separate treatment of coal discard leachate and less polluted streams would cost 3.0 million Rand (R), compared to R10.3 million for combined treatment. Only slightly less (8.9 t/d vs. 9.5 t/d) sulphate removal would be achieved during separate treatment. The over-saturation index (OSI) value can be controlled effectively by removing sulphate from the feed water for coal processing. Sulphate has to be lowered to 350 mg/L in a flow of 222 m³/h to obtain an OSI value less than 1. The capital cost of a 222 m³/h biological sulphate removal plant was estimated at R21.8 million (R4.1 million/(ML/d)); the running cost was estimated at R13.7 million/a (R4.10/m³). Pre-washing of the coal would reduce capital and running costs.     

Using Helicopter Electromagnetic Surveys to Identify Environmental Problems at Coal Mines

Abstract.  Helicopter-mounted electromagnetic (HEM) surveys have been used to delimit conductive mine pools and groundwater features at various areas in the eastern United States that contain abandoned surface and underground coal mines. HEM was used to delineate the source areas and flow paths for acidic, metal-containing groundwater. This will aid remediation efforts. A recent HEM survey of Kettle Creek Watershed, Clinton County, Pennsylvania, using a 6-frequency electromagnetic data acquisition system, is presented. The survey accurately located conductive pools within underground mines, acidgenerating mine spoil at surface mines, and areas of groundwater recharge and discharge.     

Using the GRAM Model to Reconstruct the Important Factors in Historic Groundwater Rebound in Part of the Durham Coalfield,UK

Abstract:  Modeling of mine water rebound in the southernmost zone of the Durham Coalfield has been undertaken in an attempt to reproduce observed water level recovery, since the 1970s, within five coal blocks south of the Butterknowle Fault. The lumped parameter model GRAM (groundwater rebound in abandoned mineworkings) was chosen to perform the simulations since it overcomes, to a large extent, a common problem found in such studies, namely a lack (especially concerning historic hydrogeological records) and superabundance of various kinds of data. The results obtained from this approach are satisfying and closely resemble the observed pattern of mine water rebound for the mining blocks studied. Such research indicates the critical dependence of predictions on factors such as the volume of water flowing into the system, the percentage runoff, and the value of storage coefficient assigned to the old workings. Model predictions are most useful as a tool for improving the conceptual understanding of abandoned mine systems and as a basis for evaluating alternative possibilities of coalfield behaviour, rather than as a strict quantitative assessment for all management purposes.     

Effects of a Barite Mine on Ground Water Quality in Andhra Pradesh,India

Abstract.  An investigation was undertaken to determine the effects of a large barite mining operation on local ground water quality near Mangampeta,Andhra Pradesh, India.Water samples were collected from drinking water wells in the mining and adjacent regions. The drinking water in the mining region had sulphate concentrations that ranged from 211 to 589 mg/L, compared to sulphate concentrations of 25 mg/L or less in the non-mined areas. The natural existence of barite and the widespread mine waste dumps at Mangampeta are believed to be responsible for the higher levels of sulphate in the ground water.     

Reclamation of Abandoned Coal Mine Waste in Korea using Lime Cake By-Products

Abstract.  There are hundreds of abandoned coal mines in Korea's steep mountain valleys. Enormous amounts of coal waste from these mines were dumped on the slopes, contaminating streams with sediment and acid mine drainage. A limestone slurry by-product (lime cake), which is produced during the manufacture of soda ash, was investigated for its potential use in reclaiming the coal waste. The lime cake is fine grained, has low hydraulic conductivities (10^-8 to 10^-9 cm sec^-1), high pH, high electrical conductivity, and trace amounts of heavy metals. A field experiment was conducted; each plot was 20 x 5 m in size on a 56% slope. Treatments included a control (waste only), lime (CaCO₃), and lime cake. The lime requirement (LR) of the coal waste to pH 7.0 was determined; treatments consisted of adding 25, 50, and 100% of the LR. The lime cake and lime were applied either as a layer between the coal waste and topsoil or mixed into the topsoil and waste. Each plot was hydroseeded with grasses, and planted with trees. In each plot, soils, surface runoff, and subsurface water were collected and analyzed, and plant cover was measured. Lime cake treatments increased the pH of the coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7. Moreover, the surface cover of seeded species was significantly increased; sufficient acidity in the coal waste was neutralized in the 25% LR plots to allow seed germination.     

Treatment of Mine Water by a Microbial Mat: Bench-scale Experiments

Abstract.   We investigated the treatment of acid mine drainage (AMD) by a blue-green algae-microbial consortium and substrate (containing powdered goat manure, wood chips, and soil) in 1 m³ bench scale biological treatment test cells. The microbial mat resulted from the interaction of bacteria and filamentous blue-green algae (predominantly Oscillatoria spp). The experiments were carried out for different water column heights, and were evaluated for 24, 48, 72, 96, and 168 hours of retention. Within 24 hours of retention, the pH increased from 2.93 to 6.78 as net alkalinity went from -125 mg/L to 197 mg/L as CaCO₃. Turbidity decreased by 33–54%, sulphate decreased by 23–29%, and hardness decreased by 19 to 26%. We also observed that: 95% of the Fe, 79–97% of the Cu, 84–86% of the Zn, 88% of the Pb, 59–83% of the Co, 22–62% of the Ni, and 28–45% of the Mn were removed. A blue-green algae/microbial mat consortium may be a cost–effective treatment technique for removing metals from AMD.     

Predicting Groundwater Rebound in the South Yorkshire Coalfield,UK

Abstract:  The semi-distributed model GRAM (groundwater rebound in abandoned mineworkings) has been applied to part of the South Yorkshire Coalfield, UK, to predict the pattern of groundwater rebound, in particular the timing and rates of changes in mine water flows between abandoned collieries. The model is based upon the mining hydrogeologist's concept of ‘ponds’ (discrete volumes of interconnected workings) and calculates water balances over time for all ponds in a multi-pond mined system. GRAM was successfully calibrated against observed groundwater levels over a 5 year period from 2001 to 2005 before being used to predict future rates of groundwater rebound, in accordance with different scenarios, including average, low, and high rainfall scenarios. The results reveal that it could take up to 22 years before an inflow of water occurs into the last remaining colliery in the area at Maltby, with the first surface discharge expected in approximately 15 years time from an old mine shaft. If Maltby is closed and pumping ceases across the area, then it could be 100 years before groundwater rebound is complete.     

Microbial Growth and Action: Implications for Passive Bioremediation of Acid Mine Drainage

Abstract.  Due to the variable environmental nature of mine water, several species of bacteria are important in the generation of acid mine drainage (AMD) and in bioremediation treatment technology. Enzymatic metal transport and transformation allow bacteria to survive in high-metal environments and to oxidize, reduce, and exude metals. For example, the enzymes Cr (VI) reductase and cytochrome-c3 hydrogenase allow Pseudomonas sp. to reduce Cr (VI) to less toxic Cr (III). Much more toxic organomercuric compounds are transformed by Pseudomonas fluorescens and Escherichia coli, using the enzymes organomercurial lyase and mercuric reductase. The role of bacteria in the AMD environment is not yet fully understood and consequently researchers should pay attention in this field.     

Surface Pre-grouting and Freezing for Shaft Sinking in Aquifer Formations

Abstract  Special techniques are used for shaft sinking in aquifer formations. In the unstable aquifer formations encountered in Chinese coal mines, freezing is always adopted for shaft constructions in an aquifer alluvium, while surface pre-grouting is generally adopted in bedrock formations. So far, freezing has been used to construct 500 vertical shafts, comprising a total length of 80 km, and surface pre-grouting has been used in more than 150 vertical shaft sinking projects. The maximum depth of freezing is about 700 m, while the maximum depth of surface pre-grouting exceeds 1000 m.     

Injection of Fluidized Bed Combustion Ash into Mine Workings for Treatment of Acid Mine Drainage

Abstract  A demonstration project was conducted to investigate treating acid mine water by alkaline injection technology (AIT). A total of 379 t of alkaline coal combustion byproduct was injected into in an eastern Oklahoma drift coal mine. AIT increased the pH and alkalinity, and reduced acidity and metal loading. Although large improvements in water quality were only observed for 15 months before the effluent water chemistry appeared to approach pre-injection conditions, a review of the data four years after injection identified statistically significant changes in the mine discharge compared to pre-injection conditions. Decreases in acidity (23%), iron (18%), and aluminum (47%) were observed, while an increase in pH (0.35 units) was noted. Presumably, the mine environment reached quasi-equilibrium with the alkalinity introduced to the system.     

Small-Scale Chemical Changes Caused by In-stream Limestone Sand Additions to Streams

Abstract.  In-stream limestone sand addition (ILSA) has been employed as the final treatment for acid mine drainage discharges at Swamp Run in central West Virginia for six years. To determine the small-scale longitudinal variation in stream water and sediment chemistry and stream biota, we sampled one to three locations upstream of the ILSA site and six locations downstream. Addition of limestone sand significantly increased calcium and aluminum concentrations in sediment and increased the pH, calcium, and total suspended solids of the stream water. Increases in alkalinity were not significant. The number of benthic macroinvertebrate taxa was significantly reduced but there was no effect on periphyton biomass. Dissolved aluminum concentration in stream water was reduced, apparently by precipitation into the stream sediment.     

Treatment of Acid Leachate from Coal Discard using Calcium Carbonate and Biological Sulphate Removal

Abstract.   An integrated approach is proposed for treating acidic coal discard leachate, consisting of CaCO₃ handling and dosing, CaCO₃-neutralization, and biological sulphate removal. It was found that: powdered CaCO₃ can be slurried to a constant density and used to neutralize the acid water, remove Fe (II), Fe (III), and Al, and partially remove the sulphate (to saturation level); biological sulphate removal can be used to lower the sulphate to less than 200 mg/L using ethanol as the carbon and energy source; CO₂ produced during calcium carbonate treatment can be used for H₂S-stripping and; H₂S gas recovered in the sulphate removal stage can be used for iron removal.