Reclaimed Phosphate Clay Settling Area Investigation: Hydrologic Model Calibration and Ultimate Clay Elevation Prediction
Presently operating phosphate mines in Florida have over 60,000 acres of above ground clay settling areas (CSAs), with an additional 20,000 acres designated for future CSAs. The Florida Institute of Phosphate Research sponsored a three-year project to further evaluate the unique characteristics of CSAs. This research included monitoring hydrologic and meteorological conditions, mapping soils and vegetation, and developing topographic maps using photogrammetry. Field and laboratory data were used in models to estimate the effects of clay consolidation on post-reclamation topography and to calibrate hydrologic simulation programs. This report presents the research objectives, work plan, and study results of a research project designed to monitor and evaluate the hydrology and clay consolidation behavior of phosphate CSAs. Results from this investigation indicate that CSAs discharge less surface water than previously expected, with hydrologic characteristics that change over time. Based on results from the investigation, guidelines for CSA reclamation were developed including monitoring, testing, model reevaluations and possible modification of discharge control structures at CSAs.