This document summarizes a study of the Floridan Aquifer/Chipola River System funded by the USGS and FDEP. The objectives are to identify nutrient sources to the aquifer, characterize hydrologic transport processes using modeling, and match nitrate concentrations in springs using the model. The study area includes the Dougherty Karst Plain where the Floridan Aquifer is recharged through sinkholes and rivers. A MODFLOW model is being used to simulate nitrate tracking from recharge areas and calibrate to spring discharge concentrations. Local grid refinement is being added to improve flow path and travel time estimates in key springs.