CHEMISTRY OF ABANDONED SILTATION POND WATER AND STREAM WATERS FROM A SMALL ABANDONED WALL COAL MINE ON PROPERTY IN NORTHERN BREATHITT COUNTY KENTUCKY: A CASE OF NEAR ATTENUATION

The “Wyatt” property located in Breathitt County in Eastern Kentucky consists of 750 acres of privately owned land. The property has an extensive history of varied land use which includes: farming, wall coal mining, natural gas wells, and forestry. The property is representative of many areas in the region that have extensive environmental resources and experienced a range of uses over the last 250 years. For example, hundreds of small abandoned wall mines exist in eastern Kentucky and these are not currently being investigated extensively or remediated. Whether or not small abandoned mine sites are a major environmental issue in Kentucky is not known. A basic aqueous geochemistry survey was conducted to determine if significant water quality issues exist on the Wyatt property. Water samples were collected starting at a siltation pond and followed downstream. The pH of the water samples at the siltation pond was found to have an average value of approximately 6.2. Stream pH values were found to have an average value of 5.4. Inductively coupled plasma – optical emission spectroscopy (ICP-OES) analysis of major elements showed variation with values of Ca (6.8 – 24.0 ppm), Mg (4.5-25.7 ppm), K (1.1-3.65 ppm), Na (1.5-6.75), Si (3.9-9.1 ppm), and Fe (b.d.- 2.4 ppm). Ca and Mg showed a very strong positive correlation (r²= 0.95). High performance liquid chromatography (HPLC) analysis showed concentrations of major anions to have values of Cl^- (0.5 – 22.2 ppm), SO₄^2- (7.9 – 144.1 ppm) and NO₃^- (b.d. – 0.9 ppm). Na and Cl exhibit a linear relationship but not a 1:1 ratio. Inductively coupled plasma – mass spectrometry analysis for metals of environmental concern show a range of concentrations were observed for As (0.1 – 0.7 ppb), Ba ( 2.5 – 17.6 ppb), Cr (0.3 – 0.9 ppb), Ni (0.7 – 24.6 ppb), V( 0.1 – 0.6 ppb), and Zn (0.1 – 2.85 ppb). Comparison to the U.S. Environmental Protection Agency’s maximum contaminant levels (MCLs) found that the concentrations of Cu, Ni, Cr, Zn, and As were below their MCLs. Overall water chemistry shows a single compositional trend consistent with mild acid mine drainage that appears to largely have attenuated. The results of this study serve as a comparative for other small scale coal mining sites in eastern Kentucky and demonstrate that such sites can potentially attenuate over a period of approximately 50 years.