A Feasibility Analysis of the Implementation of Passive Treatment Systems for Remediating Acid Mine Drainage in the Lick Run Watershed

Abstract

Historical mining operations, mostly coal mining, has left the State of West Virginia with many abandoned mine lands that often produce nonpoint sources of Acid Mine Drainage (AMD) pollution. This work studied a small tributary to the Cheat River, Lick Run, which has been heavily impaired by AMD through legacy coal mining. Field and laboratory water quality testing verified that Lick Run does not meet Water Quality Standards (WQS). The purpose of this research was to evaluate current stream conditions of Lick Run and to provide means of remediation through passive treatment systems to reduce metal and acidity loads. Lick Run is located in Preston County, West Virginia. Within the watershed, a total of six mine portals and three in-stream sites were monitored, along with two locations on the Cheat River. Water quality testing was performed quarterly from July 2013 to May 2014. Field tests measured pH, conductivity, total dissolved solids (TDS), dissolved oxygen (DO), and temperature. Grab samples were analyzed for pH, alkalinity, acidity, sulfate (SO4), conductivity, iron (Fe), aluminum (Al), calcium (Ca), magnesium (Mg), and manganese (Mn). Benthic macro-invertebrate communities were also assessed at the in-stream sampling locations (October 2013 and May 2014); West Virginia Stream Condition Index (WVSCI) metrics were calculated. Watershed characteristics were evaluated to help assess pollutant transfer fates. Characteristics included coal seam boundaries, elevations, soils, land use, impervious surfaces, imagery, natural wetland areas, sampling locations, problem area description locations, and abandoned mine lands. AMD Treat was utilized to help determine appropriate module dimensions and to generate cost estimates for each system. Results of the project suggest that treatment of the watershed to 80% reduction of metal and acidity loads is feasible, but capital costs are high (greater than $2,000,000). Once the proposed systems are built, however, little maintenance would be required, thus operating costs would be low during the expected lifespan of 20 years. Macro-invertebrate assessments revealed that stream conditions of Lick Run were poor to marginal. Levels of pH were below WQS with values that were nearly 4 for most sites. While this indicates considerable acid loads, these are reasonable levels for management and treatment purposes. Iron and aluminum concentrations proved to be the most detrimental to the watershed.