Assessing Water-Supply Potential of Abandoned Underground Coal Mines in Eastern Kentucky

Use of water in abandoned underground coal mines for municipal, industrial, agricultural, or domestic water supplies is dependent upon the water quantity and quality. For either of these factors, the requirements of the user will play a role in what water quantity or quality is acceptable. This report provides analysis of field-derived water-quality and -quantity characteristics for six abandoned underground coal mines in the Eastern Kentucky Coal Field. In addition, some ancillary data from State regulatory agencies were used to help characterize water quality coming from the mines. This study demonstrates that water quality in abandoned deep mines can be quite variable. Water-quality characteristics vary from mine to mine because of the position of the mine within the groundwater flow system, the mineralogy of the coal seam and the enclosing bedrock, and the time elapsed since the mine was flooded. Total dissolved solids values ranged from 194 to 2,016 µS/cm. Based on TDS, coal mines in the Manchester and Upper Elkhorn No. 3 coals produced the poorest water quality. In the study area, these seams were mined below the elevation of local drainage. The increase in TDS is a result of increased mineralization of groundwater caused by relatively slow movement and increased age of the water in the distal ends of the groundwater fl ow system. Another water-quality factor to consider in below-drainage mines is the length of time since mine closure. The time since closure and subsequent flooding of the mine is important because the reduction of acid-generating salts depends on the amount of time available for flushing. For these reasons, water quality should be analyzed for each potential water source, even within a given mine. Water-quality monitoring must include sampling and analysis during water-withdrawal testing to identify any changes in quality associated with induced mobility of otherwise slow-moving to stagnant water within a mine. Water quantity from abandoned deep mines varies greatly, depending on many variables that control flooded volume of and recharge rate to the mine. Major variables controlling groundwater discharge from a mine are the surface area overlying the mine, the position of the mine within the local and regional groundwater systems, and the structural geology of the site, which determines how groundwater drains from the mine. Recharge rates ranged from 120,000 to 1,230,000 gal/day; however, some deep mines showed net losses in storage because of lack of recharge during drought periods. This study demonstrates that water quality and quantity in abandoned deep mines are suitable for water supplies. Both quantity and quality are variable between mines, however. Variations can be attributed to geologic controls, physical setting, the age of the mine, and the rate of flushing. Therefore, water quality and quantity must be analyzed for each potential mine source, and must be analyzed throughout the time of water withdrawal

Design, Construction, and Monitoring of the Ground-Water Resources of a Large Mine-Spoil Area: Star Fire Tract, Eastern Kentucky

By the year 2010, the Star Fire mining operation in Knott, Breathitt, and Perry Counties in eastern Kentucky, which uses mountaintop-removal and hollow-fill mining techniques, will have created approximately 5,000 acres of gently rolling terrain that could support alternative land uses. The present research is centered on approximately 1,000 acres of spoil created since mining began in 1981. An aquifer fed by both ground and surface water will be created within the spoil. Spoil-handling techniques such as cast blasting, dragline placement, end dumping by trucks, and surface grading have created porous coarse-rock zones within the spoil through which ground water can move. A vertical rubble chimney in the spoil has been constructed of durable rock to enhance infiltration to the ground-water reservoir through a surface infiltration basin. Fourteen monitoring wells have been installed along with flumes to gage surface-water discharge and monitor water quantity and quality at the site. Dye-tracing studies have identified ground-water flow paths and flow velocities. A preliminary assessment of the water resources at the site indicates that a stable water table has been created at the mined site. Based on an average saturated thickness of 21 feet for the entire site and an estimated porosity of 20 percent, the spoil stores approximately 4,200 acre-feet (1.37 billion gallons) of water. Dye-tracing data, hydraulic gradients, and water-quality data indicate that ground water moves more slowly in the spoil\u27s interior; from there it flows down into the hollow fills before discharging as springs along the bottom of the spoil. The springs discharge approximately 1 million gallons per day under normal flow conditions, and discharges of approximately 5 million gallons per day have been measured a week after rainfall events

Chemical Analysis of Fish Tissue: Kentucky Army National Guard Wendell H. Ford Western Kentucky Training Site, Muhlenberg County, Kentucky

Thirty-one analytes were measured in fish tissue taken from largemouth bass, catfish, and bluegill harvested from lakes and ponds in reclaimed and unreclaimed coal-mine spoil of Pennsylvanian age. The spoil area is approximately 7,756 acres created primarily from surface mining, and has been used in increasing intensity since 1969 as a training site by the Kentucky Army National Guard. Four fish were harvested for analysis from the area of unreclaimed spoil that resulted from mining prior to 1977, and 15 fish were harvested for analysis from the part of the training facility that was reclaimed by 1985. Twenty-six analytes had values above the method reporting limit, and only one sample, L15-8A, had a mercury concentration of 1.22 mg/kg. This concentration is slightly above the federal Food and Drug Administration action concentration level of 1 mg/kg

Assessment of Groundwater Quality in a Remediated Abandoned Feedlot, Henderson County, Kentucky: Data Report

A three-phase project investigated the influence of past and present agricultural practices on groundwater resources in the Western Kentucky Coal Field. Phase III concentrated on an abandoned dairy feedlot that had been remediated. Results of phase III analyses are presented in this report

Assessment of Groundwater Quality in an Abandoned Feedlot, Henderson County, Kentucky: Data Report

A three-phase project investigated the influence of past and present agricultural practices on groundwater resources in the Western Kentucky Coal Field. Phase II concentrated on past practices, specifically those associated with an abandoned dairy feedlot and an old homestead. Results of phase II analyses are presented in this report

Assessment of Row Crop, Alfalfa, and Pasture Field Practices on Groundwater Quality in an Upland Bedrock Setting, Henderson County, Kentucky: Report of Soil- and Water-Quality Data

An assessment of how present agricultural practices have influenced shallow groundwater and soil quality was conducted on a 540-acre farm in north-central Henderson County. Groundwater- and soil-quality data were collected from row crop (corn and soybean), alfalfa, and pasture fields. In addition to the field settings, groundwater and soil data were collected from the existing farmyard and an abandoned feedlot. Groundwater samples were analyzed for pH, specific conductance, temperature, oxidation-reduction potential, metals, anions, nutrients, herbicides, and various isotopes. Soil samples were analyzed for pH, bioavailable phosphorus, potassium, calcium, magnesium, zinc, organic matter, total nitrogen, and inorganic nitrogen (nitrate-N). Soil- and groundwater-quality data are presented in the appendices

Using Remote Sensing and Inclined Drilling to Locate High-Yield Water Wells in the Eastern Kentucky Coal Field

The Kentucky Geological Survey has developed a method using lineament analysis in conjunction with inclinced exploration boreholes to identify subsurface fractures in the Eastern Kentucky Coal Field. Wells are then drilled to intersect these fractures, with the hope that the wells will be high yielding (greater than 30 gal/min). Lineaments were selected from Landsat TM imagery, side-looking airborne radar (SLAR) imagery, and two enhanced Landsat TM images for over 6,400 square miles of eastern Kentucky. Lineaments were replotted on 7.5-minute topographic quadrangle maps, and field reconnaissance identified locations where lineaments correlated with straight-line topographic features and fracture zones. Subsquent application of an inclined drilling technique at six sites has resulted in four production wells with yields ranging from 47 to 72 gal/min. All production wells intersected fractured rock. According to data from the Kentucky Groundwater Data Repository through October 2002, the yields of these four production wells are greater than the yields of 95 percent of the wells drilled in the Eastern Kentucky Coal Field. This study suggests that to minimize the chances of encountering salty groundwater, the best sites for high-yield wells are in first- or second-order stream valleys with fracture zones

Water-Quality and -Quantity Data for Abandoned Underground Coal Mines in Eastern Kentucky

Water-quality and -quantity analyses were performed between 1997 and 2003 by the Kentucky Geological Survey under contract from the Kentucky River Authority and the Kentucky Infrastructure Authority to study abandoned underground coal mines as possible water supplies for communities in the Eastern Kentucky Coal Field. The steep terrain of the coal field limits surface-water supplies, and groundwater systems are difficult to locate and often have too low a yield to provide community water supplies. KGS has been working with the Kentucky River Authority, the Kentucky Infrastructure Authority, and local government officials to search for water supplies in abandoned underground coal mines. The data in the appendices of this report are interpreted in Cumbie and others (2006)