The Water Resources Section (WRS) conducts a variety of hydrogeological investigations and acts as a scientific-technical resource to assist the groundwater data needs of state and federal agencies, other KGS sections and UK research faculty, professional geoscientists and engineers, and the general public. In addition, by legislative mandate, the WRS is responsible for maintaining the Kentucky Groundwater Data Repository (KRS 151:035) and for oversight of the Kentucky Interagency Groundwater Monitoring Network (KRS 151.625). The Section Head is Charles J. “Chuck” Taylor.
CDC Private Well Initiative
Bart Davidson completed work on a third project with the Centers for Disease Control and Prevention (CDC) in Atlanta. The CDC has initiated a nationwide project to identify and characterize private drinking-water sources, primarily wells and springs, not covered by the Safe Drinking Water Act. This project is called the Private Well Initiative. Funded through the Kentucky Division of Water, KGS proposed a pilot study to review and compile bacteriological data from private water wells collected by local and regional health departments in different geologic areas. Over 13 health departments and two state laboratories were visited, with as many telephone contacts made. In recent years, many Kentuckians are switching from water wells to city or county water supplies as their primary drinking water source. However, most health departments continue to sample a few private wells per month at homeowners’ requests. Nearly 800 bacteria records, including E. coli and Total Coliform data, were added to the Kentucky Groundwater Data Repository as a result of this project, and thereby made available for public health research. In addition, environmentalists at these health departments and laboratories were introduced to the Kentucky Groundwater Data Repository, which could assist them in their work.
Hydrology of the Cane Run Karst Watershed
WRS staff and faculty in the UK College of Agriculture and the Department of Earth and Environmental Sciences have been working in collaboration since to attempt to better quantify the discharge of water and concentrations and loads of fecal bacteria, nitrate, and suspended sediments through the Cane Run karst watershed. Cane Run, a surface stream that heads in east-central Lexington-Fayette County and extends into Scott County, drains a total area of approximately 6,070 hectares. Near the Scott-Fayette County line, the surface flow of Cane Run is pirated by series of swallow holes that are hydraulically connected to the main karst conduit of Royal Spring, the source of municipal water for Georgetown, Kentucky. KGS began monitoring flow conditions and water quality in the Royal Spring karst aquifer May 2011, using a cluster of monitoring wells located at the Kentucky Horse Park that are drilled into the Royal Spring conduit and adjacent parts of the karst aquifer. The wells have been equipped with stage recorders, a velocity meter, a 12-volt pump to collect samples, and a water-quality testing device and data logger.
WRS karst hydrogeologist Jim Currens has been conducting research into methods of accurately measuring the discharge of water and flux of potential contaminants through the Royal Spring conduit. Unlike surface streams, conduit discharge and cross-sectional area, essential to calculating the flux of contaminants, as well as water-flow velocity distribution, are difficult to determine directly. Three methods have been used to calculate the cross section of the Royal Spring karst conduit: (1) downhole video, (2) Doppler sonar, and (3) quantitative groundwater tracing. The Doppler sonar was most useful in determining passage size. To analyze the sonar data, Currens performed vector analysis which showed the direction of flow, the speed of the suspended material, and the coordinates of the location of the observation. The quantitative groundwater tracing has been the most effective tool for determining discharge because the data generated by it reflect the increasing width and depth of flow as the higher and normally air-filled conduits begin to discharge. Most of the current effort is focused on collecting discharge measurements under a variety of flow conditions to develop a more precise discharge-rating curve for the Royal Spring conduit and hence the entire Cane Run karst watershed. In addition to enabling researchers to characterize the flux of nitrate and other potential contaminants through the Cane Run watershed, the results of this research are anticipated to result in a better understanding of the role of surface water and groundwater interaction in the Inner Bluegrass karst region.
Inventory of Sinkholes and Sinkhole Occurrences
National news reporting of several incidents of large sinkhole collapses in various parts of the United States, including one near Tampa, Florida which resulted in a fatality, dramatically increased the public’s awareness and concern about sinkhole occurrences in Kentucky during 2013. WRS staff responded to approximately sixty-eight requests for information or field inspections of sinkholes occurring on private landowner’s properties. Several interviews about karst and sinkhole occurrence were also given by WRS personnel to local and regional new outlets. Since 1997, the WRS has collected information about the occurrences of cover-collapse sinkholes in Kentucky, maintaining an inventory of these features which describes their locations, physical characteristics, and topographic and geological settings. A digital GIS file of sinkholes identified and mapped throughout the state at 1:24000 scale was prepared in 2003 and is available for download at http://www.uky.edu/KGS/gis/sinkpick.htm.
Use of LiDAR Technology to Map Karst Sinkholes in Floyds Fork Watershed, Central Kentucky
To investigate new methods to improve the ease and accuracy of sinkhole identification and mapping, Junfeng Zhu has been investigating the use of digital topographic data collected using the remote sensing technology LiDAR (Light Detecting and Ranging) to identify and map sinkholes in karst areas. He and student worker Patrick Taylor developed digital LiDAR data processing methods and applied these methods to delineate sinkholes occurring in the drainage area of Floyds Fork, a surface stream draining portions of Jefferson, Oldham, Shelby, and Bullitt Counties in north-central Kentucky. Using the new LiDAR mapping method, they identified four times more probable sinkholes than could be identified using contoured depressions visible on topographic maps. A field inspection of 80 probable sinkholes located using the LiDAR mapping method indicated that interpretation of LiDAR data was 89% successful in identifying and delineating sinkhole depressions actually created by karst hydrogeologic processes.
Groundwater Contaminant Modeling at the Paducah Gaseous Diffusion Plant
Junfeng Zhu, working in collaboration with the Kentucky Research Consortium for Energy and the Environment, developed a numerical (computer) model of groundwater flow in the aquifer system present at the Paducah Gaseous Diffusion Plant, where a variety of radioactive and non-radioactive hazardous wastes were released in the past. The model will be used to help assist Department of Energy and other state and federal resource managers and contractors in remediation of groundwater at the Site by simulating the movement of contaminants. Junfeng will use the model to test the potential outcomes of different groundwater remedial actions that are being considered and employed in cleanup of the Paducah Site.
Cumberland Gap Tunnel Roadway Subsidence
The WRS staff worked in collaboration with personnel of the Kentucky Transportation Center at UK to investigate the causes of roadbed aggregate dissolution and subsidence in the Cumberland Gap Tunnel near Middlesboro, Kentucky. In a previous project completed in 2012, groundwater and roadbed drainage samples were collected and analyzed to characterize water chemistry and the dissolution of samples of limestone aggregate suspended in 2-inch-diameter stainless steel baskets in four test borings in the northbound tunnel was monitored to better understand and quantify the processes involved in the roadbed subsidence. Using geochemical modeling, Junfeng Zhu analyzed the water chemistry and dissolution data and found that water draining through the tunnels is corrosive to limestone and that in some areas within the tunnel bores the aggregate may be totally dissolved away by groundwater in 15 years. These findings have prompted KTC and federal highway engineers to initiate remedial measures to replace the existing limestone roadway aggregate with insoluble granite aggregate. Future monitoring of changes in the chemistry of water within the roadbed aggregate before, during, and after the remedial highway construction is planned. At present, water-level recorders in the tunnel are being maintained by Steve Webb to help monitor groundwater-inflow and quantify drainage through the existing roadbed aggregate.
Emerging Contaminants
According to the U.S Geological Survey, recent water resources research is “documenting with increasing frequency that many chemical and microbial constituents that have not historically been considered as contaminants are present in the environment on a global scale”. These "emerging contaminants" are commonly derived from municipal, agricultural, and industrial wastewater sources and pathways” (http://toxics.usgs.gov/regional/emc/). The U.S. EPA has also defined these contaminants as “a chemical or material that is characterized by a perceived, potential or real threat to human health or the environment or lack of published health standards. A contaminant may also be “emerging” because of the discovery of a new source or a new pathway to humans, or a new detection method or treatment technology has been developed.” These potential contaminants include antimicrobial and endocrine disruptor chemicals contained in various pharmaceuticals and personal care products (PPCPs).
In 2011-12, Glynn Beck, hydrogeologist at the KGS Western Field Office in Henderson, KY, conducted an investigation that involved the sampling of 56 surface stream sites in six watersheds in Kentucky for two emerging contaminant compounds of interest: 17-β estradiol (one of three naturally produced estrogens) and fluoroquinolones (a subset of the synthetic broad-spectrum antibacterial drugs known as quinolones antibiotics). Two of the watersheds are in the Jackson Purchase Region, two are in central Kentucky, and one each in northern and eastern Kentucky. These watersheds were chosen because they are distributed in different physiographical regions, and contain a wide variety of land-cover types (developed, cultivated, forest, and pasture). In addition, five of the six watersheds have mapped municipal waste water treatment plant outfalls, and five of the six watersheds are classified as priority watersheds by the Kentucky Division of Water.
In 2012-13, four of the six watersheds were resampled to obtain more statistically significant data. Twenty sites in the four watersheds were sampled four times each. In addition to water-quality samples, field measurements (pH, specific conductance, dissolved oxygen, temperature, and total dissolved solids) were recorded and stream discharge was measured at some of the sites.
Results from the study will be described in a KGS report presently under preparation. Among the findings: (1) Estradiol was detected in all 6 watersheds; (2) Fluoroquinolones were detected in 4 of the 6 watersheds; (3) Watersheds with the most developed land cover (South Elkhorn Creek, 24%; Banklick Creek, 36%; and Floyds Fork, 18%) had the highest detected estradiol concentrations (14.3, 11.1, and 8.2 ppt, respectively).
Sampling and analysis was funded in part by the U.S. Department of Agriculture National Institute of Food and Agriculture Southern Regional Water Program and the USGS State Water Resources Research Institute Program. The project work was also conducted in collaboration with UK Department of Biosystems and Agricultural Engineering, UK Department of Plant and Soil Sciences, and Kentucky State University College of Agriculture, Food Science and Sustainable Systems.