U.S. Department of the Interior U.S. Geological Survey Analysis of Water Levels in the Frenchman Flat Area, Nevada Test Site Water-Resources Investigations Report 00-4272 Prepared in cooperation with the U.S. DEPARTMENT OF ENERGY NEVADA OPERATIONS OFFICE under INTERAGENCY AGREEMENT DE-AI08-96NV11967 Analysis of Water Levels in the Frenchman Flat Area, Nevada Test Site By Daniel J. Bright, Sharon A. Watkins, and Barbara A. Lisle U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00-4272 Prepared in cooperation with the U.S. DEPARTMENT OF ENERGY NEVADA OPERATIONS OFFICE under INTERAGENCY AGREEMENT DE-AI08-96NV11967 Carson City, Nevada 2001 U.S. DEPARTMENT OF THE INTERIOR GALE A. NORTON, Secretary U.S. GEOLOGICAL SURVEY CHARLES G. GROAT, Director Any use of trade names in this publication is for descriptive purposes only and does not constitute endorsement by the U.S. Government For additional information Copies of this report can be contact: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Information Services 333 West Nye Lane, Room 203 Building 810 Carson City, NV 89706-0866 Box 25286, Federal Center Denver, CO 80225-0286 email: [email protected] http://nevada.usgs.gov CONTENTS Abstract.................................................................................................................................................................................. 1 Introduction............................................................................................................................................................................ 1 Purpose and Scope ..................................................................................................................................................... 3 Hydrogeology............................................................................................................................................................. 3 Acknowledgments...................................................................................................................................................... 5 Water-Level Fluctuations....................................................................................................................................................... 5 Climate and Earth Tides............................................................................................................................................. 5 Precipitation.................................................................................................................................................... 5 Barometric Pressure........................................................................................................................................ 9 Earth Tides...................................................................................................................................................... 9 Seismic Activity ......................................................................................................................................................... 9 Underground Nuclear Testing .................................................................................................................................... 11 Ground-Water Withdrawal ......................................................................................................................................... 12 Water-Level Measurements ................................................................................................................................................... 17 Periodic Measurements .............................................................................................................................................. 26 Continual Measurements............................................................................................................................................ 26 Water-Level Adjustments ...................................................................................................................................................... 26 Barometric Pressure ................................................................................................................................................... 26 Water Density............................................................................................................................................................. 28 Borehole Deviation .................................................................................................................................................... 30 Land-Surface Altitude................................................................................................................................................ 31 Analysis of Water Levels....................................................................................................................................................... 32 Statistical Analysis Methods ...................................................................................................................................... 32 Trend Analysis Results............................................................................................................................................... 33 Alluvial Aquifer.............................................................................................................................................. 35 Volcanic Aquifer............................................................................................................................................. 36 Carbonate Aquifer .......................................................................................................................................... 39 Quartzite Confining Unit ................................................................................................................................ 41 Summary ............................................................................................................................................................................... 41 References Cited .................................................................................................................................................................. 42 FIGURES 1. Map showing location of Nevada Test Site, and Frenchman Flat, Mercury Valley, and Yucca Flat Hydrographic Areas, southern Nevada .................................................................................................................. 2 2. Map showing surface distribution of rocks in the Frenchman Flat area, Nevada Test Site, Nevada.......................... 4 3-13. Graphs showing for selected areas on the Nevada Test Site: 3. Cumulative departure from mean monthly precipitation at Yucca Flat station and monthly precipitation at Mercury, well WW-5b, and Yucca Flat stations for selected periods during 1958–97 ................................. 8 4. Barometric pressure and water levels at well WW-5a for 1996 and barometric pressure at Desert Rock station near Mercury, Nevada, for 1985–96...................................................................................................... 10 5. Monthly withdrawals for selected wells in the Frenchman Flat area .................................................................. 13 6. Total annual withdrawals for wells in the Frenchman Flat area ..........................................................................18 7. Periodic water-level measurements and associated linear-regression line for selected wells in the Frenchman Flat area .......................................................................................................................................... 19 8. Continual water levels in wells SM-23, WW-5a, and WW-4a ............................................................................ 27 9. Temperature of water samples collected from selected wells in the Frenchman Flat area.................................. 29 10. Water levels in observation well WW-5a and withdrawal from water-supply wells WW-5b and WW-5c from September through December 1997 ......................................................................................................... 35 11. Water levels in wells UE-5n and RNM-2s and withdrawals from wells RNM-2s, WW-5b, and UE-5c ............ 37 CONTENTS III 12. Water-level altitudes in water-supply well WW-4 and observation well WW-4a for January–March 1993....... 38 13. Lagged water levels in wells TW-F and TW-3, cumulative departure from mean monthly precipitation at Yucca Flat station, and withdrawal from water-supply wells WW-C1, WW-C, and Army-1 in carbonate-rock aquifer....................................................................................................................................... 40 TABLES 1. Well-completion, water-level, and water-use information for wells in the Frenchman Flat area, Nevada Test Site ........ 6 2. Underground nuclear tests in the Frenchman Flat area, Nevada Test Site ........................................................................ 12 3. Annual water withdrawal from water-supply wells and test well RNM-2s in the Frenchman Flat area, Nevada Test Site, 1951–97............................................................................................................................................. 16 4. Mean, minimum, and maximum water levels and land-surface altitudes for wells in the Frenchman Flat area, Nevada Test Site ............................................................................................................................................................