Contents III 36 21. Map showing potentiometric surface of the shallow bedrock zone, June 28,1988 39 22. Cross-sectional model grid and boundaries 40 23. Hydraulic-conductivity distributions, unadjusted for horizontal anisotropy, for cross-sectional model simulations 1 and 2 42 24. Hydrograph of well 474 showing water-level fluctuations from April 1983 through September 1988 43 25. Simulated water levels and general directions of groundwater flow for cross-sectional model simulations 1 and 2 44 26-32. Maps showing: 26. Areal model grid and boundary conditions 47 27. Areal distribution of simulated recharge 48 28. Saturated thickness of layer 1, June 28,1988 50 29. Simulated water levels for layer 1 51 iv Hydrology of Melton Valley at Oak Ridge National Laboratory, Tennessee 30. Simulated water levels for layer 2 52 31. Simulated water levels for layer 3 53 32. Simulated water levels for layer 4 55 33-36. Graphs showing: 33. Changes in root mean square error of simulated water levels with respect to changes in recharge rate and layer 1 hydraulic conductivity 57 34. Changes in root mean square error of simulated water levels with respect to simultaneous changes in recharge and hydraulic conductivity 59 35. Changes in root mean square error of simulated water levels with respect to changes in layer 1 row-to-column anisotropy and layer 2 transmissivity 60 36. Changes in root mean square error of simulated water levels with respect to changes in river and drain conductance values and vertical leakance between layers 1 and 2 61 37. Map showing location of water-quality sampling sites and burial grounds 63 38. Trilinear diagram of principal-ion data of water from 31 wells in Melton Valley 69 39. Graph showing concentrations of dissolved gross beta and tritium in groundwater samples collected at Oak Ridge National Laboratory in August and September 1987 71 TABLES 1. Monthly and annual precipitation at Oak Ridge National Laboratory and normal monthly and annual precipitation at Oak Ridge, Tennessee 5 2. Results of slug tests in wells at Oak Ridge National Laboratory 9 3. Streamgaging stations on Whiteoak Creek and Melton Branch, and periods of record and drainage areas above the stations 15 4. Summary of discharge data for stations on Whiteoak Creek and Melton Branch, water year 1988, and Poplar Creek, water years 1988 and 1961 through 1988 20 5. Summary of annual discharge data, including effluent part, in cubic feet per second, for all complete years of record at stations on Whiteoak Creek and Melton Branch 21 6. Annual base flow at stations on Whiteoak Creek and Melton Branch that are not affected by effluent discharge 23 7. Estimates of annual base flow at stations on Whiteoak Creek and Melton Branch that are affected by effluent discharge 25 8. Model-calculated water-budget components for cross-sectional model simulations 45 9. Adjustments to June 28,1988, water levels used to estimate average-annual water levels 49 10. Percentage of simulated water levels within 20,10, and 5 feet of estimated averageannual water leve...
