Occurrence of Ground Water in Mine Spoil, a Renewable Resource: Star Fire Tract, Eastern Kentucky

Abstract

Toe Star Fire site is a large surface mining operation in eastern Kentucky owned and operated by Gyprus-Southem Realty. Approxlmately 10,000 acres of reclaimed, usable land will result from the ongoing mining operation by the year 201 O. Ultimately, development on the tract will depend on the avallabilityof an adequate water supply utilizing both surface and ground waters. Toe water resources of the first 1,000-acre tract of mine spoil have been investigated. Areas of groundwater recharge and discharge have been identified at the site. Major recharge enters the spoil by way of disappearing streams, groundwater flow from bedrock that is in contact with the mine spoil, and specially designed infiltration basins. Ground water discharges predominantly from springs and seeps along the western outslope of the spoil. Monitoring wells drilled into the spoil Indicate a saturated zone ranges from 8 to 25 feet in thickness. Data from waterlevel measurements, dye-tracing, and geochemical analyses of water samples indicate that a compacted haul road acts as a low-permeability barrier to groundwater movement. Water samples from surface and ground water taken from the site show that all waters are a Ca-Mg-sulfate type, differing only in the total concentration of these constituents. Specific conductance measurements of samples collected at the site ranged from 257 microsiemens In surface runoff to 3,725 microsiemens In a monitoring well situated in the interior of the spoil. The pH ranged between 6.23 and 6.66 for ground water sampled at the site, and between 7 .67 and 8.28 for surface water.

Creating a More Perennial Problem? Mountaintop Removal Coal Mining Enhances and Sustains Saline Baseflows of Appalachian Watersheds

“…Therefore, instead of increasing stormflow because of surface compaction, the valley fills increase the baseflow portion of total streamflow. Additionally, preferential flowpaths along the spoil-bedrock interface could enhance infiltration into the VF . Unfortunately, little published research provides insight on the internal structure of valley fills and how settlement or sorting of material may affect hydrologic flowpathways. ,, Greer et al, for example, demonstrated high subsurface heterogeneity in a valley fill in Virginia using electrical resistivity imaging.…”

“…Additionally, preferential flowpaths along the spoil-bedrock interface could enhance infiltration into the VF . Unfortunately, little published research provides insight on the internal structure of valley fills and how settlement or sorting of material may affect hydrologic flowpathways. ,, Greer et al, for example, demonstrated high subsurface heterogeneity in a valley fill in Virginia using electrical resistivity imaging. It is reasonable to assume that the physical characteristics of the VFs affect how much water can be stored in the VFs and how the stored water is subsequently released to sustain streamflow.…”

Reclaimed Mineland Curve Number Response to Temporal Distribution of Rainfall1

“…Average saturated thickness of the spoil aquifer was calculated at 6.5 m; measured hydraulic conductivities ranged from 6.1 × 10 −7 to >8.8 × 10 −6 m/s. Further details of mining activities, spoil construction, and mine geology and hydrogeology of the Starfire Mine are given by (Dinger et al. , 1988, 1990; Kemp, 1990; Wunsch et al.…”

The Hydrogeology and Hydrogeochemistry of the Star Fire Site, Eastern Kentucky

“…If PA < 5, the stratum is generally considered a non-acid producer, regardless of the neutralization potential (Sobek et al, 1978). water at the site (Wunsch et al 1992;Dinger et al 1990). Therefore, these points are "discussed only briefly here.…”

“…If surface-water runoff at the site were making a significant contribution to the total mine outflow, it would be expected that the TDS would be considerably less than that observed. Water from the stream at Chesnut Branch and water entering the infiltration basin have TDS concentrations that are generally less than 500 mg/L (Dinger et al 1990). …”