Groundwater Modeling and Source Study in the Turkey Creek Basin

Working closely with the Florida Institute of Technology Indian River Lagoon Research Institute (IRLRI) and funded by the State Legislature, Dr. Listopad developed a methodology for identifying groundwater sources of nutrients contributing to muck accumulation in Turkey Creek. Nutrients are contributing to muck accumulation by fueling organic blooms and hastening hyper-eutrophication. The project collected groundwater data in four select study sites in the Turkey Creek area to calibrate and refine pollutant load models. Initial exploratory work identified study areas receiving various wastewater treatment systems (septic, sanitary sewer, reclaimed water, and natural areas) that have similar flow dynamics. The project reviewed the current groundwater literature and obtained current surface and groundwater data, rainfall, elevation, septic tanks, and soil data.

Temporary and permanent wells were installed to understand groundwater levels, flows, hydraulic head, and nitrogen concentrations. Field data collection included water levels, ammonium, nitrate, TKN, and δN15 and δO18 in nitrate. Reporting included groundwater final outputs, calibration results and statistical comparisons of concentration data, water levels, and potential isotopic signatures by season and study location. This calibration data can inform various predictive models being used to estimate nitrogen concentrations. Additionally, this project is a precursor to a county-wide modeling effort using the tested and calibrated proposed methodology .