A Little Applied Geochemistry and Some Useful Physical Characteristics

1. A Little Applied GeochemistryandSome Useful Physical Characteristics Relating to Karst Aquifers Ralph O. Ewers, Ph.D. Peter J. Idstein, M.S. ewc@mis.net

2. Spring and Karst Aquifer Types Schuster and White, 1971

3. Conduit Flow Springs vs. Diffuse Flow Springs Schuster and White, 1971 After Jacobsen and Langmuir, 1974

4. Conduit Flow Springs vs. Diffuse Flow Springs Schuster and White, 1971 • These unfortunate names have prompted comments such as: • “This is a diffuse flow aquifer and therefore it must be an equivalent porous medium. Therefore, our wells should work properly and we can even model this aquifer in the standard granular aquifer manner.”

5. Conduit Flow Springs vs. Diffuse Flow Springs Schuster and White, 1971 • These unfortunate names have prompted comments such as: • “This is a diffuse flow aquifer and therefore it must be an equivalent porous medium. Therefore, our wells should work properly and we can even model this aquifer in the standard granular aquifer manner.” • The response of a person familiar with carbonate aquifers: • Only a tiny fraction of the carbonate aquifers of the world are truly equivalent porous media. • Traditional methods in very highly fractured carbonates or those possessing significant inter-granular permeability may appear to predict tolerable head response and production values. • Traditional methods do not provide useful predictions relative to contaminant transport in most carbonates.

6. Quick-flow Recharge vs. Seepage Recharge Schuster and White, 1971 After Jacobsen and Langmuir, 1974

7. Coefficients of Variation Jacobsen and Langmuir, 1974

8. Coefficients of Variation Jacobsen and Langmuir, 1974

9. Coefficients of Variation Jacobsen and Langmuir, 1974

10. Hydraulic Conductivity Measurements In Karst (Quinlan, Worthington and Davies, 1992; Teutsch and Sauter, 1992; Worthington, 1992)

11. Sinkholes DO NOT Define Karst • Many demonstrably karst aquifers do not have them • Conduits formed by dissolution of the carbonate rock do define them.

12. Sinkholes DO NOT Define Karst • Many demonstrably karst aquifers do not have them • Conduits formed by dissolution of the carbonate rock do define them. 18Miles

13. High Level Overflow Routes Between Basins May Complicate a Site

14. Traditional Potentiometric Surface Maps are Reliable ONLY at Regional Scale

15. Groundwater Flow is CONVERGENTIn Karst, Not Divergent and Dispersive

16. Digital Data Loggers An Asset in Understanding Karst Aquifers

17. A typical Installation with auto-sampler

19. Campbell 21X and CR-10 Series

20. Stage SensorDruck Pressure Transducer

21. Conductivity SensorA Simple Proprietary Device

22. Temperature SensorPlatinum Resistance Thermometer

23. Typical Data-Logger Program Measure 10 seconds Measure 10 Seconds Measure 10 Seconds “ “ “ “ “ “ “ “ “ Calculate 2 Minute Average Compare To Previously Stored Value Same Different Store New Value

24. A phreatic conduit system

25. An epiphreatic or vadose conduit system

27. END Part 4