This research investigated the effect of quick-release and slow-release fertilizers on the transport of nitrate through the subsurface. The main focus of this study was studying nitrate concentrations in subsurface water samples over time, particularly in the presence of overfertilization. Evaluating nitrate movement allowed for assessment of the potential for contamination of shallow groundwater systems. Rainfall data was also evaluated to see the effects that precipitation had on nitrate concentration trends. Additionally, soil was studied to evaluate nitrate soil water concentrations and organic matter content. It was concluded that nitrate concentrations remained elevated above the Maximum Contaminant Level (MCL) of 10 mg/L nearly a year after initial fertilizer applications for both fertilizer types and moved past the rooting zone of plants. The data also suggested that fertilizer plays a larger role on changes in nitrate concentrations than increased precipitation. The conclusions of this study emphasize the need for fertilizer users to more fully understand their soil and vegetation’s nutritional needs prior to fertilizer application. Over-fertilization can have long term consequences, including the potential to pollute shallow groundwater systems.