Geospatial Evaluation of Acid Mine Drainage Potential from Historic Coal Mines in Chattanooga, Tennessee

Abstract. Chattanooga has undergone a remarkable transformation from a heavily industrialized rail depot and one of the nation’s most polluted cities to the first designated National Park City in the United States of America. However, environmental challenges remain, particularly in nearby Soddy Daisy area, where historic coal mining continues to pose potential risks to water quality through acid mine drainage (AMD). This study evaluates the risk of AMD from abandoned coal mines along Walden Ridge using geospatial analysis. Mine locations were identified through mineral surveys, topographic maps, and field knowledge, while hydrologic features were digitized to overcome gaps in existing datasets. A suitability model was developed using a digital elevation model (DEM) and proximity analysis of geospatial data to predict areas most vulnerable to contamination. Among the sixty-eight coal mines evaluated, twenty-four were categorized as high risk, seven as marginal risk, and thirty-seven as low or no risk. Results indicate that although fewer mines than expected pose an immediate threat, high-risk mines tend to occur in clusters, intensifying localized impacts. Northern Big Possum Creek and the confluence of Deep Creek and Carr Branch were identified as priority areas for remediation. These findings highlight the enduring legacy of coal mining in the region and underscore the need for targeted mitigation strategies to protect water resources.