The Kentucky Geological Survey and the Kentucky Division of Water are evaluating groundwater quality throughout the commonwealth to determine regional conditions, assess impacts of nonpoint-source contaminants, provide a baseline for tracking changes, and provide essential information for environmental-protection and resource-management decisions. These evaluations include summarizing existing regional groundwater-quality data and reporting the results of expanded, focused groundwater collection programs in specific areas. This report summarizes groundwater sampling and analysis in Kentucky basin management unit 5 (watersheds of the Big Sandy River, Little Sandy River, and Tygarts Creek in eastern Kentucky).
Thirty wells and springs were sampled quarterly between the fall of 2002 and the summer of 2003. Temperature, pH, and conductance were measured at the sample site, and concentrations of a selected group of major and minor inorganic ions, metals, nutrients, pesticides, and volatile organic chemicals were measured at the Kentucky Division of Environmental Services laboratory. The new analytical data were combined with groundwater-quality records retrieved from the Kentucky Groundwater Data Repository. This repository is maintained by the Kentucky Geological Survey and contains reports received from the Division of Water’s Ambient Groundwater Monitoring Program as well as results of investigations by the U.S. Geological Survey, U.S. Environmental Protection Agency, U.S. Department of Energy, Kentucky Geological Survey, Kentucky Division of Pesticide Regulation, and other agencies. Statistical measures such as the number of measured concentrations reported, the number of sites sampled, quartile values (maximum 75th percentile, median, 25th percentile, and minimum), and the number of sites at which water-quality standards were exceeded were used to summarize the data, and probability plots were used to illustrate the distribution of reported concentrations. Maps were used to show well and spring locations and sites where water-quality standards were met or exceeded. Box-and-whisker diagrams were used to compare values between major watersheds, water from wells versus water from springs, and total versus dissolved metal concentrations. Plots of concentrations versus well depth were used to compare groundwater quality in shallow, intermediate, and deep groundwater flow systems.
Table A1 summarizes the findings. Water properties, inorganic anions, and metals are primarily controlled by natural factors such as bedrock lithology. Some exceptionally high values of conductance, chloride, and sulfate may be affected by nearby oil and gas production, leaking waste-disposal systems, or other human factors, and some exceptionally low pH values may indicate acid mine drainage. Ammonia and nitrate concentrations indicate a probable contribution from nutrient applications and waste-disposal practices. Synthetic organic chemicals such as pesticides and refined volatile organic compounds do not occur naturally. Although these chemicals rarely exceed water-quality criteria in the project area, their detection indicates there has been some degradation of groundwater quality. The occurrence of these synthetic chemicals should continue to be monitored, and renewed efforts are needed to protect the groundwater resource.
Report of Investigations 19
Digital Object Identifier (DOI)
Funding for this project was provided in part by a grant from the U.S. Environmental Protection Agency as authorized by the Clean Water Act Amendments of 1987, Section 319(h) Nonpoint Source Implementation Grant C9994861-01.
Fisher, R. Stephen; Davidson, Bart; and Goodmann, Peter T., "Groundwater Quality in Watersheds of the Big Sandy River, Little Sandy River, and Tygarts Creek (Kentucky Basin Management Unit 5)" (2008). Kentucky Geological Survey Report of Investigations. 21.