1. Nutrient and Pesticide Accounting in the Chipola River/Floridan Aquifer System—Update Presented by Rick Hicks of FDEP And Christy Crandall of USGS This Study Jointly Funded by U.S. Geological Survey and Florida Department of Environmental Protection

2. STUDY OBJECTIVES Identify significant nutrients and pesticides inputs to the Chipola River/Floridan aquifer system using existing informationIdentify significant nutrients and pesticides inputs to the Chipola River/Floridan aquifer system using existing information Characterize the hydrologic and geochemical processes occurring along flowpaths using a groundwater flow and tracking model and a geochemical model along flow paths.Characterize the hydrologic and geochemical processes occurring along flowpaths using a groundwater flow and tracking model and a geochemical model along flow paths. Test 1 or possibly 2 hypothetical scenarios—tracking nitrate and maybe an organic compound to the Jackson Blue Spring and the Chipola River.Test 1 or possibly 2 hypothetical scenarios—tracking nitrate and maybe an organic compound to the Jackson Blue Spring and the Chipola River. Provide a model that will assist in predicting spring and ground water impacts from land use modificationsProvide a model that will assist in predicting spring and ground water impacts from land use modifications

3. BACKGROUND

4. Chipola Watershed Study Area Location

5. Vertically contiguous thick sequence of limestone and dolostone of late Paleocene to early Miocene ageVertically contiguous thick sequence of limestone and dolostone of late Paleocene to early Miocene age Highly potable--drinking water is derived from Floridan aquifer systemHighly potable--drinking water is derived from Floridan aquifer system Contains numerous springs, sinks and other karst features—highly vulnerable.Contains numerous springs, sinks and other karst features—highly vulnerable. Floridan Aquifer System

6. The Floridan Aquifer and the Chipola River Basin Recharge occurs mainly in unconfined and semi-confined areas Potentiometric surface— flows southward from northern extent

7. Ground water makes up the majority of the Chipola River's discharge during low and medium flow conditions At least 63 springs identified(Barrios and Chellette, 2004) The Floridan Aquifer and the Chipola River Basin

8. Higher nitrate concentrations and more occurrances of nitrate and pesticides in the Chipola River and Floridan aquifer in this area than in other areas of the Floridan aquifer system (U.S. Geological Survey data).Higher nitrate concentrations and more occurrances of nitrate and pesticides in the Chipola River and Floridan aquifer in this area than in other areas of the Floridan aquifer system (U.S. Geological Survey data).

9. Progress

10. 1) Acquired and compiled existing data

11. 2. Selected and sampled field parameters, NO 3, and E.Coli at contributing springs and in the Chipola River (57 sites total sampled)

12. Preliminary Nitrate Results in mg/L as N

13. Preliminary E.Coli. Results In count per 100 ml

14. 3. Used preliminary data to target 3 flowpaths and obtained permission to sample wells within these flowpaths: -2 flowpaths were selected for nutrient issues - 1 flowpath was selected for E.Coli

15. 4 ) Sampled 3 wells along each flowpath for major ions, nutrients, age tracers, isotopes, pesticides, pharmaceuticals, field parameters

16. The 3 Selected Flowpaths With preliminary NO 3 in mg/L as N From all data and networks -most flowpath data is not back from the lab yet.

17. 4. Continue to build and calibrate a ground-water flow and particle- tracking model for the Floridan Aquifer/Chipola River system —progress

18. Existing Finite Element Ground- water Flow Model Boundaries (2) Tallahassee New MODFLOW based Ground- water Flow Model Boundary

19. GW Flow Model is built in MODLFOW using the following data and parameters from Finite element Model: Hydraulic parameters Aquifer tops and bottoms Pumping data Recharge Boundary conditions River stage and parameters Starting heads

20. Model Currently running in MODLFOW but still needs work: Boundary conditions are not working properly yet.Boundary conditions are not working properly yet. Currently working on this as Rick is giving this talk.Currently working on this as Rick is giving this talk. Will have to adjust parameters from old model during calibration.Will have to adjust parameters from old model during calibration.

21. Timetable Model calibration completed by 12/07Model calibration completed by 12/07 Particle tracking along flowpaths hopefully completed by 03/08Particle tracking along flowpaths hopefully completed by 03/08