Groundwater Quality in Watersheds of the Kentucky River, Salt River, Licking River, Big Sandy River, Little Sandy River, And
Total Page:16
File Type:pdf, Size:1020Kb
1 Groundwater Quality in Watersheds of the Kentucky River, Salt River, Licking River, Big Sandy River, Little Sandy River, and Tygarts Creek (Kentucky Basin Management Units 1, 2, and 5) R. Stephen Fisher1 Bart Davidson1 Peter T. Goodmann2 Abstract The Kentucky Geological Survey, University of Kentucky, and the Kentucky Division of Water (of the Kentucky Environmental and Public Protection Cabinet) are evaluating ground- water quality throughout the commonwealth to determine regional conditions, assess impacts of nonpoint-source pollutants, establish a basis for detecting changes, and provide essential informa- tion for environmental-protection and resource-management decisions. These evaluations are being conducted in stages. Under the Kentucky Watershed manage- ment Framework, Kentucky’s 12 major river basins and tributaries of the Ohio River were grouped into fi ve basin management units (BMU’s). A previous report summarized and evaluated ground- water quality in BMU 3 (watersheds of the Upper Cumberland River, Lower Cumberland River, Tennessee River, the Jackson Purchase Region, and adjacent Ohio River tributaries). That report is available on the KGS Web site (www.uky.edu/KGS/water/RI_15/). This report summarizes results of analyses of groundwater samples from wells and springs in BMU 1 (Kentucky River watershed and adjacent Ohio River tributaries), BMU 2 (Salt River and Licking River watersheds and adjacent Ohio River tributaries), and BMU 5 (Big Sandy River, Little Sandy River, and Tygarts Creek watersheds, and adjacent Ohio River tributaries). Analytical results for selected water properties, major and minor inorganic ions, metals, nu- trients, pesticides, and volatile organic chemicals were retrieved from the Kentucky Groundwater Data Repository. The 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 data from investigations by the U.S. Geological Survey, U.S. Environmental Protection Agency, U.S. Department of Energy, Kentucky Geological Survey, Kentucky Division of Pesticide Regu- lation, and other agencies. The Kentucky Division of Water provided water-quality standards. Statistics such as the number of measurements reported, the number of sites sampled, quartile con- centration values, and the number of sites at which water-quality standards were met or exceeded are used to summarize the data. Maps show sampled locations and sites where water-quality stan- dards were met or exceeded. Cumulative data plots are used to show concentration distributions 1Kentucky Geological Survey 2Kentucky Division of Water 2 Abstract in each basin management unit. Box-and-whisker diagrams compare values between physiographic regions, major watersheds, wells and springs, and total versus dissolved metal concentrations. Plots of analyte concentrations ver- sus well depth compare groundwater quality in shallow, intermediate, and deep groundwater fl ow systems. Table A1 summarizes the fi ndings. General water-quality properties, inorganic anions, and metals are pri- marily controlled by natural factors such as bedrock lithology. Some exceptionally high values of conductance, hardness, chloride, and sulfate may be affected by nearby oil and gas production or improperly sealed oil and gas wells, leaking waste-disposal systems, or other man-made factors, and some exceptionally low pH values probably result from acid mine drainage. Nitrate concentrations show a strong contribution from agricultural and waste-disposal practices, whereas orthophosphate and total phosphorus concentrations are largely determined Table A1. Summary of evidence for nonpoint-source impacts on groundwater quality in basin management units 1, 2, and 5. No Strong Evidence for Evidence for Some Evidence for Defi nite Parameter Widespread Nonpoint- Nonpoint-Source Impact Nonpoint-Source Impact Source Impact Conductance X Hardness X Water pH X Properties Total dissolved solids X Total suspended solids X Chloride X Inorganic Sulfate X Ions Fluoride X Arsenic X Barium X Metals Iron X Manganese X Mercury X Ammonia-nitrogen X Nitrate-nitrogen X Nutrients Nitrite-nitrogen X Orthophosphate X Total phosphorus X 2,4-D X Alachlor X Pesticides Atrazine X Cyanazine X Metolachlor X Simazine X Benzene X Volatile Ethylbenzene X Organic Toluene X Compounds Xylenes X MTBE X 1 Methyl tertiary-butyl ether Previous Investigations 3 by the chemical composition of limestone bedrock and coal strata. Synthetic organic chemicals such as pesticides and refi ned volatile organic compounds do not occur naturally in groundwater. Although these chemicals rarely exceed water-quality criteria in the project area, the detection of these man-made chemicals in springs and shallow wells indicates there has been some degradation of groundwater quality. Monitoring of these synthetic, potentially health-threatening chemicals should continue, and efforts to protect the groundwater resources from them should be a priority for the commonwealth of Kentucky. tors make replacing groundwater with surface-water Introduction supplies expensive or impractical in rural areas, and Purpose because some cities along the Ohio River are turning Evaluating groundwater quality is essential for to groundwater from alluvial deposits for urban water determining its suitability for various uses and the supplies. An estimated 400,000 Kentuckians will still sources of dissolved chemicals, and because regional depend on private, domestic water supplies in the year groundwater quality provides a sensitive indicator of 2020 (Kentucky Geological Survey, 1999). the general condition of the natural environment. This Both natural and man-made processes affect report summarizes groundwater quality in the north- groundwater quality. The major natural processes that eastern part of Kentucky (watersheds of the Kentucky contribute cations, anions, metals, nutrients, and sedi- River, Salt River, Licking River, Big Sandy River, Little ment to groundwater are dissolution of atmospheric Sandy River, and Tygarts Creek, and Ohio River tribu- gases as rain falls through the atmosphere, dissolution taries adjacent to those watersheds). Similar reports on of soil particles and physical transport of chemicals groundwater quality in the southwestern part of Ken- and sediment as rainfall fl ows across the land surface, tucky were previously completed (Fisher and others, dissolution of soil gases and reactions with inorganic 2004). and organic material in the soil zone above the water table, and reactions with gases, minerals, and organic Goals material beneath the water table. The goals of this report are to summarize regional Groundwater quality is also affected by human values for a group of groundwater-quality parameters activities that contribute synthetic organic chemicals and to determine whether nonpoint-source chemicals such as pesticides, fertilizers, and volatile organic com- have affected groundwater systems. The results identi- pounds, as well as cations, anions, metals, nutrients, fy natural and anomalous concentrations of dissolved and sediment, to the water system. Nearly all activities chemicals, show areas where nonpoint-source chemi- that threaten surface waters and aquatic ecosystems cals have entered the groundwater system and imple- also endanger groundwater systems. Agriculture, con- mentation of best management practices are needed, fi ned animal-feeding operations, forestry, mining, oil provide information for Kentucky Division of Water and gas production, waste disposal, and urban storm- watershed assessment reports, provide groundwater- water runoff can deliver pesticides, fertilizers, nutri- quality data to the DOW’s Groundwater Protection ents, metals, and hydrocarbons to groundwater. program, help the DOW’s Wellhead Protection pro- gram set priorities to protect areas and activities, and Previous Investigations provide critical information for long-term protection Numerous reports covering the study area or and management of water resources. nearby areas describe the hydrology, groundwater re- sources, and general water quality of the study area. Background Few address the issue of nonpoint-source contamina- Evaluating groundwater quality is particularly tion, however. In the 1960’s and early 1970’s, the U.S. important in Kentucky because groundwater use is Geological Survey published reconnaissance studies extensive and will continue to be so. The 1990 cen- of the geology, groundwater supplies, and general sus data and recent DOW estimates indicate that ap- groundwater quality in Kentucky. These reports in- proximately 60 percent of public water-supply compa- clude a Hydrologic Atlas series, which was made in nies use groundwater as a sole or contributing water conjunction with the Kentucky Geological Survey; source, more than 25 percent of the population uses each atlas covers from two to 10 counties across the groundwater for domestic purposes, and more than state (except in the Jackson Purchase area, which had 226 million gallons of groundwater are consumed dai- coverage for each 7.5-minute quadrangle). Each atlas ly by individuals, municipalities, utilities, businesses, includes three sheets showing geology, lithology, and and farms. Groundwater will continue to be important availability of groundwater. The atlases have been to Kentuckians because economic and logistical fac- 4 Project Area scanned and are currently available online (www.uky. The project area includes six of Kentucky’s phys- edu/KGS/water/library/USGSHA.html).