SEARCH · Search USGS
Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
This report lists data on ground-water levels for 16 wells and discharge for 18 springs in the Spring Mountain area of the Tolyabe National Forest. Water levels in wells ranged from 325 to 519 feet below land surface. The highest spring discharge listed is 107 gallons per minute. In addition, data on the chemical quality of the water from selected wells and springs are listed.
Nevada's reliance on ground-water resources has increased because of increased development and surface-water resources being fully appropriated. The need to accurately quantify Nevada's water resources and water use is more critical than ever to meet future demands. Estimated ground-water pumpage, artificial and natural recharge, and interbasin flow can be used to help evaluate stresses on aquifer systems. In this report, estimates of ground-water pumpage and artificial recharge during calendar year 2000 were made using data from a variety of sources, such as reported estimates and estimates made using Landsat satellite imagery. Average annual natural recharge and interbasin flow were compiled from published reports. An estimated 1,427,100 acre-feet of ground water was pumped in Nevada during calendar year 2000. This total was calculated by summing six categories of ground-water pumpage, based on water use. Total artificial recharge during 2000 was about 145,970 acre-feet. At least one estimate of natural recharge was available for 209 of the 232 hydrographic areas (HAs). Natural recharge for the 209 HAs ranges from 1,793,420 to 2,583,150 acre-feet. Estimates of interbasin flow were available for 151 HAs. The categories and their percentage of the total ground-water pumpage are irrigation and stock watering (47 percent), mining (26 percent), water systems (14 percent), geothermal production (8 percent), self-supplied domestic (4 percent), and miscellaneous (less than 1 percent). Pumpage in the top 10 HAs accounted for about 49 percent of the total ground-water pumpage. The most ground-water pumpage in an HA was due to mining in Pumpernickel Valley (HA 65), Boulder Flat (HA 61), and Lower Reese River Valley (HA 59). Pumpage by water systems in Las Vegas Valley (HA 212) and Truckee Meadows (HA 87) were the fourth and fifth highest pumpage in 2000, respectively. Irrigation and stock watering pumpage accounted for most ground-water withdrawals in the HAs with the sixth through ninth highest pumpage. Geothermal production accounted for most pumpage in the Carson Desert (HA 101). Reinjection of ground water pumped for geothermal energy production accounted for about 64 percent (93,310 acre-feet) of the total artificial recharge. The only artificial recharge by water systems was in Las Vegas Valley, where 29,790 acre-feet of water from the Colorado River was injected into the aquifer system. Artificial recharge by mining totaled 22,870 acre-feet. Net ground-water flow was estimated only for the 143 HAs with available estimates of both natural recharge and interbasin flow. Of the 143 estimates, 58 have negative net ground-water flow, indicating that ground-water storage could be depleted if pumpage continues at the same rate. The State has designated HAs where permitted ground-water rights approach or exceed the estimated average annual recharge. Ten HAs were identified that are not designated and have a net ground-water flow between -1,000 to -35,000 acre-feet. Due to uncertainties in recharge, the water budgets for these HAs may need refining to determine if ground-water storage is being depleted.
The investigation of the ground-water resources of Monmouth County is part of a Statewide water-resources program. This study was made by the U.S. Geological Survey in cooperation with the new Jersey Department of Conservation and Economic Development, Division of Water Policy and Supply. It was under the general direction of Philip E. LaMoreaux, Chief of the Ground Water Branch of the U.S. Geological Survey, and under the direct supervision of Allen Sinnott, District Geologist. This report presents data for most of the public-supply wells and for several irrigation wells in Monmouth County. The data for these wells are believed to be representative of large-capacity wells tapping the major aquifers present in the county. The information is released at this time in advance of an interpretive report because of its value to prospective users of ground water in Monmouth County. An earlier report presented data on small-capacity wells tapping both major and minor aquifers in the county. The data in these two reports form, in part, the basis for a comprehensive interpretive report on the ground-water resources of Monmouth County, now in preparation. Also to be included in the latter report are data for certain large-capacity industrial wells.
In San Juan County, Colo., the effects of historical mining continue to contribute metals to ground water and surface water. Previous research by the U.S. Geological Survey identified ground-water discharge as a significant pathway for the loading of metals to surface water in the upper Animas River watershed from both acid-mine drainage and acid-rock drainage. In support of this ground-water research effort, Prospect Gulch was selected for further study and the geochemistry of surface and ground water in the area was analyzed as part of four sampling plans: (1) ten streamflow and geochemistry measurements at five stream locations (four locations along Cement Creek plus the mouth of Prospect Gulch from July 2004 through August 2005), (2) detailed stream tracer dilution studies in Prospect Gulch and in Cement Creek from Gladstone to Georgia Gulch in early October 2004, (3) geochemistry of ground water through sampling of monitoring wells, piezometers, mine shafts, and springs, and (4) samples for noble gases and tritium/helium for recharge temperatures (recharge elevation) and ground-water age dating. This report summarizes all of the surface and ground-water data that was collected and includes: (1) all sample collection locations, (2) streamflow and geochemistry, (3) ground-water geochemistry, and (4) noble gas and tritium/helium data.
This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Geauga County Planning Commission and Board of County Commissioners, to determine directions of ground-water flow and to assess differences from 1986 to 1994 in groundwater levels in the glacial deposits and Pottsville Formation, Cuyahoga Group, and the Berea Sandstone. Water levels were measured in 219 wells in Geauga County, Ohio, in September 1994. Water levels measured in January and February 1986 in 88 of the 219 wells were used for comparison. Water-level maps constructed from measurements made in September 1994 show that ground-water levels in the Pottsville Formation and the glacial deposits generally correspond to the land-surface configuration and that ground water flows from the uplands to adjacent streams and buried valleys. Ground-water flow in the Cuyahoga Group is generally downward from the Pottsville Formation to the Berea Sandstone. Directions of ground-water flow in the Berea Sandstone are toward outcrop areas at the north and east edges of Geauga County and toward subcrops beneath buried glacial valley deposits in Chardon, Chester, Munson, and Russell Townships and along the west edge of the county. A comparison of water level measurements in 1986 and 1994 indicates that water levels declined in 70 percent of the measured wells and increased in 30 percent. The change in water levels from 1986 to 1994 ranged from an increase of 13.58 feet to a decrease of 29.25 feet. Thirty percent of all water-level changes were less than 1 foot in magnitude. In nearly 80 percent of the wells, water-level changes were within the range of plus or minus 5 feet. Among the wells for which two or more historical measurements were available, the 1994 water levels in 54 percent were outside the range of water-levels observed in previous studies (only 24 percent were greater than 1 foot outside of the previously-observed range). Water-level declines of greater than 10 feet were primarily in the Cuyahoga Group and Berea Sandstone. Some factors considered in the analysis of the differences in water levels in 1986 and 1994 were changes in water use, population, and the amount of available recharge. Water level differences could not be correlated to population changes between the 1980 and 1990 censuses. A decrease in the available recharge from 1986 to 1994 may be part of the cause for the decrease in water levels observed in two-thirds of the wells in and adjacent to Geauga County. Effects of withdrawal rates due to population increase on water levels, if present, are overshadowed by the effects of annual variations in precipitation.
The Environmental Restoration Program of the U.S. Department of Energy, Nevada Operations Office, was developed to investigate the possible consequences to the environment of 40 years of nuclear testing on the Nevada Test Site. The majority of the tests were detonated underground, introducing contaminants into the ground-water system (Laczniak and others, 1996). An understanding of the ground-water flow paths is necessary to evaluate the extent of ground-water contamination. This report provides information specific to Yucca Flat on the Nevada Test Site. Critical to understanding the ground-water flow beneath Yucca Flat is an understanding of the subsurface geology, particularly the structure and distribution of the pre-Tertiary rocks, which comprise both the major regional aquifer and aquitard sequences (Winograd and Thordarson, 1975; Laczniak and others, 1996). Because the pre-Tertiary rocks are not exposed at the surface of Yucca Flat their distribution must be determined through well logs and less direct geophysical methods such as potential field studies. In previous studies (Phelps and others, 1999; Phelps and Mckee, 1999) developed a model of the basement surface of the Paleozoic rocks beneath Yucca Flat and a series of normal faults that create topographic relief on the basement surface. In this study the basement rocks and structure of Yucca Flat are examined in more detail using the basement gravity anomaly derived from the isostatic gravity inversion model of Phelps and others (1999) and high-resolution magnetic data, as part of an effort to gain a better understanding of the Paleozoic rocks beneath Yucca Flat in support of groundwater modeling.
Recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, Nevada, and California, from the adjacent Carson Range and Pine Nut Mountains ranged from 22,000 to 40,000 acre-feet per year using water-yield and chloride-balance methods. In this study, watershed models were developed for watersheds with perennial streams and for watersheds with ephemeral streams in the Carson Range and Pine Nut Mountains to provide an independent estimate of ground-water inflow. This report documents the development and calibration of the watershed models, presents model results, compares the results with recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, and presents updated estimates of the ground-water budget for basin-fill aquifers of Carson Valley. The model used for the study was the Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Geographic Information System software was used to manage spatial data, characterize model drainages, and to develop Hydrologic Response Units. Models were developed for * Two watersheds with gaged perennial streams in the Carson Range and two watersheds with gaged perennial streams in the Pine Nut Mountains using measured daily mean runoff, * Ten watersheds with ungaged perennial streams using estimated daily mean runoff, * Ten watershed with ungaged ephemeral streams in the Carson Range, and * A large area of ephemeral runoff near the Pine Nut Mountains. Models developed for the gaged watersheds were used as index models to guide the calibration of models for ungaged watersheds. Model calibration was constrained by daily mean runoff for 4 gaged watersheds and for 10 ungaged watersheds in the Carson Range estimated in a previous study. The models were further constrained by annual precipitation volumes estimated in a previous study to provide estimates of ground-water inflow using similar water input. The calibration periods were water years 1990-2002 for watersheds in the Carson Range, and water years 1981-97 for watersheds in the Pine Nut Mountains. Daily mean values for water years 1990-2002 were then simulated using the calibrated watershed models in the Pine Nut Mountains. The daily mean values of precipitation, runoff, evapotranspiration, and ground-water inflow simulated from the watershed models were summed to provide annual mean rates and volumes for each year of the simulations, and mean annual rates and volumes computed for water years 1990-2002. Mean annual bias for the period of record for models of Daggett Creek and Fredericksburg Canyon watersheds, two gaged perennial watersheds in the Carson Range, was within 4 percent and relative errors were about 6 and 12 percent, respectively. Model fit was not as satisfactory for two gaged perennial watersheds, Pine Nut and Buckeye Creeks, in the Pine Nut Mountains. The Pine Nut Creek watershed model had a large negative mean annual bias and a relative error of -11 percent, underestimated runoff for all years but the wet years in the latter part of the record, but adequately simulated the bulk of the spring runoff most of the years. The Buckeye Creek watershed model overestimated mean annual runoff with a relative error of about -5 percent when water year 1994 was removed from the analysis because it had a poor record. The bias and error of the calibrated models were within generally accepted limits for watershed models, indicating the simulated rates and volumes of runoff and ground-water inflow were reasonable. The total mean annual ground-water inflow to Carson Valley computed using estimates simulated by the watershed models was 38,000 acre-feet, including ground-water inflow from Eagle Valley, recharge from precipitation on eolian sand and gravel deposits, and ground-water recharge from precipitation on the western alluvial fans. The estimate was in close agreement with that obtained from the chloride-balance method, 40,000 acre-feet, but was considerably greater than the estimate obtained from the water-yield method, 22,000 acre-feet. The similar estimates obtained from the watershed models and chloride-balance method, two relatively independent methods, provide more confidence that they represent a reasonably accurate volume of ground-water inflow to Carson Valley. However, the two estimates are not completely independent because they use similar distributions of mean annual precipitation. Annual ground-water recharge of the basin-fill aquifers in Carson Valley ranged from 51,000 to 54,000 acre-feet computed using estimates of ground-water inflow to Carson Valley simulated from the watershed models combined with previous estimates of other ground-water budget components. Estimates of mean annual ground-water discharge range from 44,000 to 47,000 acre-feet. The low range estimate for ground-water recharge, 51,000 acre-feet per year, is most similar to the high range estimate for ground-water discharge, 47,000 acre-feet per year. Thus, an average annual volume of about 50,000 acre-feet is a reasonable estimate for mean annual ground-water recharge to and discharge from the basin-fill aquifers in Carson Valley. The results of watershed models indicate that significant interannual variability in the volumes of ground-water inflow is caused by climate variations. During multi-year drought conditions, the watershed simulations indicate that ground-water recharge could be as much as 80 percent less than the mean annual volume of 50,000 acre-feet.
This report is intended to serve two purposes: (1) to make available to the public basic ground-water data useful in planning and studying development of water resources, and (2) to supplement an interpretive report that will be published later. Records were collected during the period 1935-64 by the U.S. Geological survey in cooperation with the Utah State Engineer as part of the investigation of ground-water conditions in the Sevier Desert, in Juab and Millard Counties, Utah. The interpretive material will be published in a companion report by R. W. Mower and R. D. Feltis. This report is most useful in predicting conditions likely to be found in areas that are being considered as well sites. The person considering the new well can spot the proposed site on plate 1 and examine the records of nearby wells as shown in the tables and figures. From table 1 he can note such things as depth, diameter, water level, yield, use of water, temperature of water, and depth of perforations. By comparing the depth of perforations with the drillers' logs in table 3 he can note the type of material that yields water to the wells. Table 2 and figure 2 show the historic fluctuations and trends of water levels in the vicinity. From table 4 he can note the chemical quality of the water from wells in the vicinity. Table 5 shows the amount of water discharged during 1951-63 from the pumped irrigation, public supply, and industrial wells. If the reader decides from his examination that conditions are favorable, he can place an application to drill a well with the state Engineer. If the State Engineer believes unappropriated water is available, the application may be approved after minimum statutory requirements have been satisfied. The report is also useful when planning large-scale developments of water supply. This and other uses of the report will be helped by use of the interpretive report upon its release.
A contour map showing minimum depth to ground water from 1973 through 1979 was constructed for the upper Santa Ana River valley region. The map was prepared as an initial step in an ongoing liquefaction-potential study, but is not a liquefaction-hazard map. The contour map indicates where ground water shallower than 50 ft below land surface occurred at least once during the 1973-1979 period, and also indicates the probable future distribution of ground water shallower than 50 ft below land surface for periods when climatic conditions and water-management policies similar to those in the 1970's recur. This contour map does not show how the water table actually looked at any particular instant during the reporting period, nor does it show average or typical ground-water conditions during the reporting period. Instead, this map shows what the regional ground-water table would look like if the shallowest water level measured in each well during the 1973-1979 period is used as the basis for constructing a map of minimum depth to ground water. This map identifies twenty areas within the upper Santa Ana River valley where water levels in wells were shallower than 50 ft below land surface at least once during the period 1973-1979. In the greater Santa Ana River area, between the San Jacinto ground-water barrier and Prado flood-control dam, ground water was shallower than 50 ft below land surface intermittently throughout the 1973-1979 period. In this area, shallow water generally reflects shallow depths to impermeable bedrock and the ease and frequency with which ground water is replenished by natural and artificial recharge. Most of the other areas of shallow ground water identified on this map experienced pervasive shallow water levels only after mid-1977. Prior to mid-1977, ground water in these areas generally was deeper than 50 ft below land surface. During later parts of the 1973-1979 period, water tables rose mainly because of two factors: (1) wetter-than-normal winters in 1977-1978 and 19781979 contributed increased volumes of surface runoff and natural recharge in the upper Santa Ana River valley region; and (2) commencing in 1972, ground water in the Valley region has been replenished by artificial recharge of imported water derived from the California State Water Project. The accelerated natural and artificial recharge of ground water basins in 1977, 1978, and 1979 raised ground water tables throughout the Valley region. Water-level records more recent than September 1979 indicate that for most of the twenty areas of shallow ground water, water levels have remained shallower than 50 ft below land surface through December 1981. In some areas, water levels have risen even more. For example, in the San Bernardino area, rising water locally has invaded basements, undermined roadways, and affected foundation construction. Where post-1979 water levels have continued to rise, the areas underlain by shallow ground water have expanded and now are larger than the areas shown on the contour map of this report.
This report describes the availability, quantity, quality, variability, and cost of development of the ground-water resources in the lower Susquehanna River basin. The report has been prepared for and under specifications established by the Corps of Engineers, U. S. Army, and the Public Health Service, Department of Health, Education, and Welfare. A comprehensive study of the water and related land resources of the Susquehanna River basin was authorized by the Congress of the United States in October 1961, and the task of preparing a report and of coordinating the work being done by others in support of the study was assigned to the Corps of Engineers. The comprehensive study is being conducted by several Federal departments and independent agencies in cooperation with the States of New York, Pennsylvania, and Maryland. The Public Health Service under its authority in the Federal Water Pollution Control Act (P. L. 660) initiated a comprehensive water quality control program for the Chesapeake drainage basin, which includes the Susquehanna River basin. This report is intended to serve the specific needs for ground-water information of both the Corps of Engineers and the Public Health Service, as well as those of the other participating Federal and State agencies.
Ground-water data for the Baker County-northern Malheur area, Oregon, are tabulated for the Bureau of Land Management. The data include well and spring records, a well-location map, drillers' logs of wells, observation-well hydrographs, and chemical analyses of ground-water samples. The reported yields of wells and springs in the area ranged from less than 1 to 2,500 gallons per minute. Dissolved solids in ground-water samples ranged from 50 to 1,587 milligrams per liter, and arsenic ranged from 0.001 to 0.317 milligrams per liter.
This memorandum summarizes briefly the data obtained by test drilling and in an aquifer test at Mount Airy, Md. The tests were a part of the State - Federal cooperative study of the ground-water resources of Frederick County, and it is intended that a more complete analysis of the test data will be included in a future report describing the ground-water resource of Frederick County. The purpose of this memorandum is to make the test data immediately available to the general public. Mount Airy is located along the Carroll-Frederick County boundary bout 2 miles north of the intersection of U.S. Highway 40 with the county boundary. Its population is approximately 1,000. The municipal well field, consisting of two drilled wells (fig. 1) is in a valley about one-half mile west of the center of Mount Airy, within about 400 feet of a small stream, and north of Prospect Road. Well 1, about 40 feet north of Prospect Road, is 125 feet deep, 8 inches in diameter, and reportedly yielded 265 gallons per minute (gpm) in 1947 and 201 gpm in a half hour test in March 1955. The writer determined during the tests described in this memorandum that the well has about 34 feet of casing. Well 2, 85 feet north of well 1, is 96 feet deep, 8 inches in diameter, and reportedly yielded 120 gpm in 1947 and 127 gpm in a half hour test in March 1955. The wells are equipped with deep-well turbine pumps powered by electric motors. Cenorally only well 1 is used, and it is pumped for only a few short intervals each day to meet the water requirements of the town (about 75,000 - 80,000 gallons daily). The reported yields of these wells are considerably higher than the average for crystalline-rock wells in the Piedmont of Maryland. The test drilling was done under contract with Edward I. Brown, well driller, between May 3 and May 12, 1955. Water-supply facilities of the town of Mount Airy were kindly made available for the aquifer tests from May 22 to May 30, 1955. The pumping tests consisted of a step-drawdown and interference test on the public-supply wells on May 30, 1955, and aquifer test in which public-supply well 1 was pumped constantly for 48 hours and the effect of this pumpage was measured in all the wells and test holes on May 23-25.
A cooperative observation-well monitoring program was begun in New Mexico in 1925 between the U.S. Geological Survey and the New Mexico State Engineer Office. The majority of the wells are located in New Mexico; however, a few are in Texas east of Curry and Roosevelt County, New Mexico, and in Colorado along the Rio Grande. The program presently includes 22 wells equipped with continuous water-level recorders and 34 monitoring areas in which selected wells are measured periodically, usually every 5 years, to record changes in ground-water levels. These monitoring areas are those where ground water is used in large quantities for irrigation, municipal, or industrial purposes. Water-level data and water-level changes computed from these data are used to determine areas of ground-water-level rises and declines. This information is necessary for management of ground-water resources in New Mexico. Included in this report are hydrographs of ground-water levels obtained from 22 wells equipped with continuous water-level recorders and maps of ground-water-level changes computed for a 5-year period in each of 34 monitoring areas. Well locations and ground-water-level data for a 5-year period are listed in tables for each monitoring area. Where available, plots of annual precipitation data for climatological stations within or adjacent to each monitoring area are included.
This is a supplement to the report, ' Effect of pumpage on ground-water levels as modeled in Laramie County, Wyoming, ' published as U.S. Geological Survey Water-Resources Investigations Open-File Report 80-1104. The computer program and data used to model ground-water conditions in post-Cretaceous rocks in Laramie County are listed. (USGS)
The U.S. Geological Survey (USGS) and the city of Cedar Rapids conducted a cooperative study from 1992 to 1996 to assess the hydrogeology and water quality in the Cedar River, Cedar River alluvial aquifer, Devonian aquifer, and Silurian aquifer in a 231-square-mile area of Benton and Linn Counties near Cedar Rapids, Iowa. The city of Cedar Rapids withdrew an average of 34 million gallons per day between July 1,1995, and June 30, 1996, from the Cedar River alluvial aquifer for its drinking-water supply. The ground-water flow system in the 231-square-mile area was simulated using a modular, three-dimensional, finite-difference groundwater flow model (MODFLOW) under steady-state conditions. The three-layer groundwater flow model simulates ground-water flow in layer 1 for unconsolidated deposits that include the Cedar River alluvial aquifer; in layer 2 for the Devonian aquifer and buried-channel aquifer; and in layer 3 for the Silurian aquifer. Primary sources of inflow to the ground-water flow system in the model area include infiltration of precipitation (63.5 percent) and leakage from the Cedar River (34.7 percent). Pumpage from municipal, industrial, and private wells accounts for about 48.3 percent of system outflow. Primary sources of inflow to the Cedar River alluvial aquifer include leakage from the Cedar River (74.2 percent), leakage from adjacent or underlying hydrogeologic units (20.9 percent), and infiltration of precipitation (4.9 percent). Pumpage by municipal water-supply wells from the alluvial aquifer accounts for about 78.0 percent of system outflow. Simulations of two hypothetical conditions using the steady-state ground-water flow model were conducted to evaluate quantitative changes on sources of water to the Cedar River alluvial aquifer. Results for the scenario representing a period of less-than-average annual precipitation for 1961-90 indicate a 32.0-percent reduction of total ground-water flow and a 5.7-percent increase in river leakage to the Cedar River alluvial aquifer. Results for the scenario representing increased pumping from the Cedar River alluvial aquifer, with pumping increased 68.3 percent from about 41 million gallons per day (for the calibrated model) to about 70 million gallons per day, indicate a 70.9-percent increase in simulated river leakage. Commonly used herbicides in Iowa such as atrazine (and the metabolite products deethylatrazine and deisopropylatrazine), cyanazine, and metolachlor, when detected in the Cedar River alluvial aquifer, were typically at small concentrations (less than 1.0 microgram per liter). Atrazine concentrations in 26 of the 64 wells sampled were less than the 0.05 microgram per liter minimum reporting level. Most ground-water samples collected from the Devonian and Silurian aquifers had herbicide concentrations less than 0.05 microgram per liter. Nitrite-plus-nitrate nitrogen (nitrate) concentrations in ground-water samples varied from less than the minimum reporting level (0.05 milligram per liter) to 15.0 milligrams per liter. Nitrate was not detected in samples from 18 wells, and nitrate concentrations greater than the Maximum Contaminant Level for nitrate as nitrogen (10 milligrams per liter) were detected in samples from 4 wells. Several areas in the Cedar River alluvial aquifer with large iron and manganese concentrations could be related to the original depositional environment of the sediment. In general, large iron and manganese concentrations in ground water are often associated with abundant organic and argillaceous material in sediment near old meander channels and sloughs.
This report is an index of all surface-water, ground-water, and quality-of-water data which have been or are now being collected on a continuous or periodic basis, by the U. S. Geological Survey and the cooperating agencies in the Delaware River basin, to September 30, 1951. The index is divided into two principal sections, the surface-water section relating to streams and the ground-water section to wells and springs. Each section contains an index of records on quality of water. All surface-water data in this report are classified by stream name and state. The ground-water data are classified by state and county inasmuch as most ground-water studies and compilations are made on the basis of a county as a unit. Lists of selected publications relating to surface and ground waters appear at the end of the respective sections. These lists include not only most of the publications issued or prepared by the Geological Survey, but also a representative group of publications prepared elsewhere, particularly reports concerned with large parts of, or the entire, basin. Those Federal, State, and municipal agencies now engaged in cooperative water-resources investigations with the Geological Survey are listed in a section following the ground-water portion of this report. In addition to the data indicated in this index, the Geological Survey has obtained information at many miscellaneous localities throughout the Delaware River basin. Much of this information is available to the public upon application to the Survey field offices, and to facilitate the use of these miscellaneous data, a list of the field offices having
As part of the U.S. Geological Survey's National Water-Quality Assessment program, an analysis of the existing ground-water-quality data in the Upper Colorado River Basin study unit is necessary to provide information on the historic water-quality conditions. Analysis of the historical data provides information on the availability or lack of data and water-quality issues. The information gathered from the historical data will be used in the design of ground-water-quality studies in the basin. This report includes an analysis of the ground-water data (well and spring data) available for the Upper Colorado River Basin study unit from water years 1972 to 1992 for major cations and anions, metals and selected trace elements, and nutrients. The data used in the analysis of the ground-water quality in the Upper Colorado River Basin study unit were predominantly from the U.S. Geological Survey National Water Information System and the Colorado Department of Public Health and Environment data bases. A total of 212 sites representing alluvial aquifers and 187 sites representing bedrock aquifers were used in the analysis. The available data were not ideal for conducting a comprehensive basinwide water-quality assessment because of lack of sufficient geographical coverage. Evaluation of the ground-water data in the Upper Colorado River Basin study unit was based on the regional environmental setting, which describes the natural and human factors that can affect the water quality. In this report, the ground-water-quality information is evaluated on the basis of aquifers or potential aquifers (alluvial, Green River Formation, Mesaverde Group, Mancos Shale, Dakota Sandstone, Morrison Formation, Entrada Sandstone, Leadville Limestone, and Precambrian) and land-use classifications for alluvial aquifers. Most of the ground-water-quality data in the study unit were for major cations and anions and dissolved-solids concentrations. The aquifer with the highest median concentrations of major ions was the Mancos Shale. The U.S. Environmental Protection Agency secondary maximum contaminant level of 500 milligrams per liter for dissolved solids in drinking water was exceeded in about 75 percent of the samples from the Mancos Shale aquifer. The guideline by the Food and Agriculture Organization of the United States for irrigation water of 2,000 milligrams per liter was also exceeded by the median concentration from the Mancos Shale aquifer. For sulfate, the U.S. Environmental Protection Agency proposed maximum contaminant level of 500 milligrams per liter for drinking water was exceeded by the median concentration for the Mancos Shale aquifer. A total of 66 percent of the sites in the Mancos Shale aquifer exceeded the proposed maximum contaminant level. Metal and selected trace-element data were available for some sites, but most of these data also were below the detection limit. The median concentrations for iron for the selected aquifers and land-use classifications were below the U.S. Environmental Protection Agency secondary maximum contaminant level of 300 micrograms per liter in drinking water. Median concentration of manganese for the Mancos Shale exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level of 50 micrograms per liter in drinking water. The highest selenium concentrations were in the alluvial aquifer and were associated with rangeland. However, about 22 percent of the selenium values from the Mancos Shale exceeded the U.S. Environmental Protection Agency maximum contaminant level of 50 micrograms per liter in drinking water. Few nutrient data were available for the study unit. The only nutrient species presented in this report were nitrate-plus-nitrite as nitrogen and orthophosphate. Median concentrations for nitrate-plus-nitrite as nitrogen were below the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter in drinking water except for 0.02 percent of the sites in the alluvial aquifer and 0.03 percent of the sites in the Mancos Shale. Concentrations of orthophosphate did not vary significantly among aquifers or land-use classifications. Historic water-quality data from wells and springs helped to characterize the regional distribution of ground-water quality information in the Upper Colorado River Basin study unit. The historical ground-water data summarized in this report will be used in the design of a ground-water-quality network. Because ground-water-quality issues in the study unit are related to high dissolved solids, sulfate, selenium, and nutrients, this report discusses some of the important findings related to these issues.
This report describes the geography, geology, and ground-water resources of Wichita and Greeley counties in western Kansas. The area consists of a flat to gently rolling plain, which slopes eastward [at] about 15 feet per mile. A short reach of Ladder Creek (Beaver) is the only perennially flowing stream in the two counties. Ephemeral streams, which flow only during and after heavy rains, are White Woman and Sand Creeks and the western reach of Ladder Creek. The climate is semiarid, the normal annual precipitation being about 17 inches in Wichita County and 16 inches in Greeley County. Agriculture is the principal occupation in the area, and wheat is the most important crop. A considerable area is irrigated; sugar beets and sorghums are the principal irrigated crops. The outcropping rocks range in age from late Cretaceous to Recent; the Smoky Hill chalk member of the Niobrara formation, which is exposed along White Woman Creek in western Greeley County, is the oldest. The Niobrara is almost everywhere overlain by the Ogallala formation of Pliocene age. Generally the Ogallala is overlain by windblown silt of the Pleistocene Sanborn formation, but in places it is exposed along streams. The most recent deposits are dune sand and the alluvium along the streams. The Dakota formation, which is an important aquifer in parts of Kansas, is 300 to 450 feet beneath the Niobrara formation. The ground water that is available to wells in Wichita and Greeley counties is derived entirely from precipitation in the area or in areas immediately west and north. Ground water moves in a generally easterly direction with a gradient that varies inversely with the permeability of the water-bearing beds. The ground-water reservoir is recharged principally by precipitation within the area or within adjacent areas, Ground-water discharge takes place principally by pumping from wells, subsurface outflow, and evaporation and transpiration. Most of the domestic, stock, public, and irrigation supplies are obtained from wells. It is estimated that probably more than 2 billion gallons of water is pumped annually from wells in the area. Since 1947, ground-water recharge has been about equal to ground-water discharge. The use of ground water for irrigation has increased greatly since 1946 and indications are that many more wells may be drilled and pumped without dangerously lowering the water table. Approximately 11,000 to 12,000 acres were irrigated in 1951. A map showing the thickness of water-bearing materials indicates that although much of the area has enough water-bearing material to support irrigation wells, parts of Wichita and Greeley counties have little or none. The Ogallala is the principal water-bearing formation in the area. Small amounts of water may also be obtained locally from alluvial deposits and from cracks in the Niobrara formation. Two deep test wells to the Dakota formation have been drilled but, because of the poor quality of the water, have never been used. The ground water in Wichita and Greeley counties, though hard, is suitable for most purposes. Water from the Ogallala is generally high in fluoride and in some cases may be injurious to the teeth of children. Water from the Dakota, though soft, is unfit for irrigation because of a high content of sodium. The field data upon which most of this report is based are given in tables; they include records of 417 wells, chemical analyses of 31 samples of water, and logs of 57 test holes and wells.