Wekiva River Nitrogen Load Allocation Study

Dr. Souto and Dr. Listopad completed this unique watershed research project that examined relationships among socio-economic groups, human behavior, and water quality data taking geospatial and, potentially, temporal distributions into account. The Wekiva Nitrogen Source Allocation Study completed in 2009, was unparalleled because it parsed out sources of nitrogen based on land use and refined them based on the residents’ land management techniques. This was one of the earliest research studies attempting to integrate behavior data into pollutant load models. The outcome of the research resulted in a modification to the watershed-loading model.

The relative contribution of polluted groundwater had to be considered as the Wekiva River is a spring-fed river. The project strategy was to estimate nitrogen loads from residential lands in the Wekiwa springshed and then ground-truth the load estimates by monitoring groundwater nutrient concentrations within the neighborhoods. Dr. Souto, Principal Investigator, conducted a representative telephone survey within the watershed and a door to door interviews of residents. Dr. Souto recruited homeowners to allow well installation and sampling in their yards. She managed quality assurance, analysis of water quality and social data. Results were discussed in white papers and peer-review journal articles. Twenty-four groundwater wells were installed using direct push and drill rig technology. These were sampled quarterly for 18 months. The research had many interesting findings, including the importance of fertilizer (both agricultural and residential) as source nitrogen loads, the spatial distribution of residential fertilizer use in relation to both median household value and, most importantly, location of golf courses.

Dr. Listopad was the lead geospatial and geostatistician on the team. She was also involved in water quality analyses, database development, and impervious area extraction using remote sensing, geostatistical analyses and multivariate analyses, and reporting.

Project Manuscript