Head-of-Rough Spring Discharge and Water-Quality Characterization

Hardin County Water District No. 1 (HCWD1) and the Kentucky Geological Survey (KGS) propose a collaborative investigation to improve monitoring and knowledge of discharge and water-quality characteristics of Head-of-Rough Spring. Data and findings obtained from the project will provide HCWD1 with information needed to revise the present water-withdrawal permit and improve the source-water protection plan (SWPP) for the spring, located in a karst sinkhole plain near Elizabethtown, Ky. Karst springs such as Head-of-Rough are the outlets for water discharging from subsurface conduit drainage basins that are recharged in part by surface runoff collected by sinkholes and sinking streams. Groundwater recharge and water quality in Head-of-Rough spring basin are affected by land-use practices and potential contaminants that infiltrate the soil and that leak, spill, or are flushed into the subsurface. Suspended sediment is one potential source of contamination and water-quality degradation that may adversely affect water treatment processes and the use of Head-of-Rough spring as a source of public water provided by HCWD1. The proposed project will involve the installation of a continuous monitoring station capable of collecting near-real-time data to track and assess variability in the discharge (flow), water temperature, pH, specific conductance, and turbidity of Head-of-Rough spring. The KGS shall install, operate, and maintain the monitoring station for a period of at least 1 year and shall directly gage the spring discharge at least once a month to enable development of a stage (waterlevel)- discharge rating curve. The continuous-monitoring data will be collected at 15-30 minute intervals, uploaded to a cloud-based webserver by satellite telemetry once every four hours, and downloaded and displayed as hydrographs on a KGS managed website to enable daily tracking of changes in water availability and field water-quality indicators. In addition, HCWD1 personnel will collect water samples monthly at the Pirtle Spring water treatment plant from the raw water intake from Head-of-Rough spring which will be analyzed by the KGS Water Laboratory for total suspended solids (TSS). Additional sediment samples will be collected at more frequent intervals over two storm-pulse events, once during the spring and once during the fall, as determined by local weather conditions and telemetered stage-discharge hydrograph data. Collection of turbidity readings and suspended sediment samples, along with the spring discharge data, will enable calculation of sediment loads and determination of the relationship between turbidity probe readings and suspended sediment concentrations and loads discharging from the spring. These data will significantly improve HCWD1’s ability to rapidly assess local karst basin flow conditions, optimize water treatment processes, and maximize the use of Headof- Rough spring as a reliable public water source.