Recommended Strategies for the Response to Hazardous Materials Releases in Karst

Abstract

The US Environmental Protection Agency has identified karst aquifers as one of the most vulnerable aquifer types to contamination. Many karst aquifers have a direct connection to the surface through sinkholes, sinking streams, fractures and faults, and cave entrances. Thin soils or soils containing root zones, desiccation cracks, and animal burrows provide little filtration or retention of contaminants. Karst aquifers are noted for rapid recharge, high groundwater velocities, and little attenuation of contaminants. The release of hazardous materials into a karst terrain can result in a direct and rapid impact to groundwater resources, surface, and groundwater ecological systems and threaten public and private water supplies. Most industrialized and urbanized communities have well-developed hazardous materials (Hazmat) response teams to contain and mitigate hazards. However, Hazmat teams may not understand some of the unique aspects of karst terrains, and remediation measures to prevent direct exposure to a release. This may result in unforeseen contamination of groundwater resources. This paper is intended to identify potential strategies to mitigate potential impacts from the release of hazardous materials in karst terrains. This includes preplanning with hazardous materials response professionals, hydrogeologic research, techniques to investigate potential receptors, and on-site remediation and monitoring recommendations that include special considerations in karst.