29-4 A Geochemical Study of Acid Mine Drainage at the Ravenscroft Mine in White Co., Tennessee

Session: Undergraduate Research, Part II (Posters)

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Abstract:

Acid mine drainage (AMD) is a biogeochemical process that is associated with metallic ore and coal deposits. The oxidation of sulfide minerals (commonly pyrite) in these deposits generates sulfuric acid which lowers the pH of the surrounding soil, surface water and groundwater. Additionally, these reactions also release metals into the environment, such as aluminum, iron and zinc. In the U.S., AMD impacts over 20,000 km of streams causing a degradation of water quality and biodiversity in affected soil and water.

The Ravenscroft mine near Sparta, TN began operation in 1902. It was one of several area coal mines that operated until 1936. The mine consisted of a vertical shaft 178 ft deep, a tipple to load coal into hopper cars and a powerplant. Part of the mining operation was the removal of subsurface rock to access the coal. Waste rock was brought up to the surface forming large coal refuse piles. Oxidation of these refuse piles produces acidic leachate that enters the soil, groundwater and flows away from the site as runoff. Today, the Ravenscroft mine is a historic site with a walking trail.

This research expands on a study by Mofield (2024) on evaluating the potential for AMD at the Ravenscroft mine. Mofield (2024) determined that the coal refuse produces acidic leachate with conductivities of 54-281 µS/cm, indicating the presence of dissolved ions. In this study, we tested the AMD for over 20 metals and 8 anions as well as other water properties such as hardness, conductivity and dissolved organic content (DOC). Preliminary results show that spring and stream water sampled in May-October 2025 had a pH that ranged from 3.4-6.9 and that the AMD contained elevated concentrations of aluminum (up to 14.3 mg/L), iron (13.2 mg/L) and sulfate (157 mg/L). Iron precipitate staining is ubiquitous in streams on and off the mining site including Buck Creek, a tributary of the Calfkiller River to the northwest. Streams and ponds on the site contain few if any fish, insects or macroinvertebrates. Site investigation indicates that the mine tailings extend far off the site and have the potential to generate AMD over a large area. Future work will map the extent of the coal refuse and generation of AMD.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1, 2026

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