Environmental Contaminants in Coal Slurry Intended for Underground Injection in the State of West Virginia

Abstract

Waste from coal cleaning processes includes coarse size fractions (i.e., coarse refuse) and small particles (i.e., fine refuse). The aqueous suspension of fine refuse, referred to as coal slurry, frequently contains potentially toxic substances, including hydrocarbons, heavy metals, and coal cleaning chemicals. Disposal of coal slurry using underground injection has raised environmental concerns because it may lead to contamination of groundwater and water supplies. In the present study, liquid and solid fractions of coal slurries collected from five underground injection sites and one coal preparation site in West Virginia (WV) were analyzed for a suite of 177 organic and inorganic constituents. The original data presented in this article were all collected by the WV Department of Environmental Protection, Office of Mining and Reclamation, and the U.S. Department of Interior, Office of Surface Mining, with input from the WV Department of Health and Human Resources. Several metals of health and environmental concern, including aluminum, antimony, arsenic, iron, lead, and manganese, were detected at concentrations exceeding the U.S. EPA environmental guidelines. Total suspended solids, pH, and inorganic ions, including nitrite, chloride, fluoride, and sulfate, were also measured at levels above the U.S. EPA guidelines at one or more sites. Several volatile and semivolatile organic compounds listed in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Priority List of Hazardous Substances were positively detected, but at concentrations well below the U.S. EPA environmental guidelines. The present study provides new information about the chemical composition of coal slurry from different sites in WV that will be useful for environmental and health risk assessment.