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USGS1994

Review of literature on the testing of point-velocity current meters

The U.S. Geological Survey is in the process of evaluating point-velocity current meters. As part of this evaluation process, a review of the literature pertaining to the testing of point-velocity current meters was conducted. A listing of current-meter testing found in the literature was compiled and is grouped according to the type of meter tested and the type of test conducted. Meter types included in the review were vertical- and horizontal-axis mechanical current meters and electromagnetic acoustic electronic current meters. Laser current meters are not included in the review because there are no practical laser meter designs for field velocity measurements. The results of the literature review indicated that there has not been a comprehensive testing of the commonly available current meters since the 1920's.

Open-File Report↗

USGS2002

Cyclic injection, storage, and withdrawal of heated water in a sandstone aquifer at St. Paul, Minnesota--Analysis of thermal data and nonisothermal modeling of short-term test cycles

In May 1980, the University of Minnesota began a project to evaluate the feasibility of storing heated water (150 degrees Celsius) in the Franconia-Ironton Galesville aquifer (183 to 245 meters below land surface) and later recovering it for space heating. The University's steam-generation facilities supplied high-temperature water for injection. The Aquifer Thermal-Energy Storage system is a doublet-well design in which the injection-withdrawal wells are spaced approximately 250 meters apart. Water was pumped from one of the wells through a heat exchanger, where heat was added or removed. This water was then injected back into the aquifer through the other well. Four short-term test cycles were completed. Each cycle consisted of approximately equal durations of injection and withdrawal ranging from 5.25 to 8.01 days. Equal rates of injection and withdrawal, ranging from 17.4 to 18.6 liters per second, were maintained for each short-term test cycle. Average injection temperatures ranged from 88.5 to 117.9 degrees Celsius. Temperature graphs for selected depths at individual observation wells indicate that the Ironton and Galesville Sandstones received and stored more thermal energy than the upper part of the Franconia Formation. Clogging of the Ironton Sandstone was possibly due to precipitation of calcium carbonate or movement of fine-grain material or both. Vertical-profile plots indicate that the effects of buoyancy flow were small within the aquifer. A three-dimensional, anisotropic, nonisothermal, ground-water-flow, and thermal-energy-transport model was constructed to simulate the four short-term test cycles. The model was used to simulate the entire short-term testing period of approximately 400 days. The only model properties varied during model calibration were longitudinal and transverse thermal dispersivities, which, for final calibration, were simulated as 3.3 and 0.33 meters, respectively. The model was calibrated by comparing model-computed results to (1) measured temperatures at selected altitudes in four observation wells, (2) measured temperatures at the production well, and (3) calculated thermal efficiencies of the aquifer. Model-computed withdrawal-water temperatures were within an average of about 3 percent of measured values and model-computed aquifer-thermal efficiencies were within an average of about 5 percent of calculated values for the short-term test cycles. These data indicate that the model accurately simulated thermal-energy storage within the Franconia-Ironton-Galesville aquifer.

Professional Paper↗

USGS2023

Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21

The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth Air Force Base (study area). Natural gamma and electromagnetic induction data were collected to refine or determine surficial deposit thickness at selected wells. Additionally, data from previous geophysical studies and driller logs were compiled and combined with results from natural gamma and electromagnetic induction data to provide a more spatially complete image of the subsurface. Borehole nuclear magnetic resonance (bNMR) data were collected to estimate hydraulic conductivity and water content of surficial deposits overlying Pierre Shale. Simple aquifer tests using water slugs (slug tests) were completed to estimate hydraulic conductivity of surficial deposits, and results were compared to hydraulic conductivity estimates from bNMR data. All data used to construct maps and estimate hydraulic properties are provided in an accompanying U.S. Geological Survey data release (available at https://doi.org/10.5066/P9FLR79F ). Generalized contour maps were constructed using results from 26 borehole geophysical logs, 35 geophysical transects from previous studies, and 304 wells with driller logs. Pierre Shale elevation generally followed land-surface topography, sloping from high elevations in the north to lower elevations in the south. Topographic highs of Pierre Shale, where present, could act as groundwater divides that potentially affect groundwater flow direction. Surficial deposit thickness varied spatially and ranged from 0 to 86 feet. Surficial deposits generally were thickest in higher elevation areas near ephemeral streams in the northern part of the study area. Hydraulic conductivity estimated from bNMR results using two analytical methods ranged from 0.1 to 2,314 feet per day, whereas hydraulic conductivity estimated from slug tests ranged from 0.001 to 193 feet per day. Hydraulic conductivity estimates from slug tests were plotted with surficial deposit thickness contours instead of bNMR estimates because bNMR estimates were determined to overestimate hydraulic conductivity. Hydraulic conductivity values generally were greater in the southwestern part of study area than the northeastern part.

South Dakota↗

USGS2004

Distribution of methyl tert-butyl ether (MTBE) and selected water-quality constituents in the surficial aquifer at the Dover National Test Site, Dover Air Force Base, Delaware, 2001

A joint study by the Dover National Test Site, Dover Air Force Base, Delaware, and the U.S. Geological Survey was conducted from June 27 through July 18, 2001, to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site. This report provides a summary assessment of the distribution of methyl tert-butyl ether and a preliminary screening of selected constituents that may affect natural attenuation and remediation demonstrations at the Dover National Test Site. The information gathered during this study is designed to assist potential remedial investigators who are considering conducting a methyl tert-butyl ether remedial demonstration at the test site. In addition, the study supported a planned enhanced bioremediation demonstration and assisted the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. A direct-push drill rig was used to collect a total of 147 ground-water samples (115 VOC samples and 32 quality-assurance samples) at varying depths. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloro-ethene, 1.14 micrograms per liter of trichloro-ethene, 2.65 micrograms per liter of tetrachloro-ethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest concentrations of methyl tert-butyl ether were detected in the surficial aquifer from ?4.6 to 6.4 feet mean sea level; however, methyl tert-butyl ether was detected as deep as ?9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations that were found in association with the ground-water samples that contained methyl tert-butyl ether are preliminary indicators that will assist in determining if natural attenuation of methyl tert-butyl ether is occurring in the surficial aquifer. A full assessment of natural attenuation of methyl tert-butyl ether at the site is beyond the scope of this study, but the data collected during the study will be useful in selecting appropriate remedial methyl tert-butyl ether demonstrations.

Delaware↗

USGS2004

Use of short-term (5-Minute) and long-term (18-Hour) leaching tests to characterize, fingerprint, and rank mine-waste material from historical mines in the Deer Creek, Snake River, and Clear Creek Watersheds in and around the Montezuma Mining District, Colorado

Precipitation-induced runoff from historical mine-waste located adjacent to the headwaters of the Snake River, Deer Creek, Saints John Creek, Grizzly Gulch, Stevens Gulch, and Leavenworth Creek contributes to the degradation of water quality in these streams. Because historical mine-waste piles have had long-term exposure to the atmosphere, it is surmised that runoff from these piles, induced by meteorological events such as cloudbursts and snowmelt, may cause mobility of acid and metals into a watershed due to dissolution of soluble minerals. For this study, 13 mine-waste composite samples from various mine-wastes in these drainage basins were leached using both a short-term and a long-term leach test. Analytical results from this combination of leach tests are tools that allow the investigator to quantify (fingerprint) which geochemical components could be expected in runoff from these piles if they were leached by a cloudburst (5-minute leach test), as well as what the ?worst-case? geochemical profile would look like if the material were subject to extended leaching and breakdown of the mine-waste material (18-hour leach test). Also, this combination of leach tests allows the geoscientist the ability to see geochemical changes in the mine-waste leachate over time. That is, does the leachate become more or less acidic over time; does the specific conductance increase or decrease; and are there changes in the concentrations of major or trace elements? Further, use of a ranking scheme described herein will aid in prediction of which historical mine-waste piles have the greatest potential for impact on a watershed should runoff occur. Because of long-term weathering of these historical mine-waste piles, geochemical profiles, leachate time-trends, and relative ranking of the mine-wastes produced from analysis of the leachates are Hageman_SIR_2508.doc 1 7/21/2004 2:50 PM indicative of how the mine-waste piles can be expected to act in the environment and may help to identify the ?bad actors??this may aid in understanding the reasons for water-quality differences between the drainages.

Scientific Investigations Report↗

USGS2005

Hydraulic characterization of overpressured tuffs in central Yucca Flat, Nevada Test Site, Nye County, Nevada

A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

Nevada↗

USGS2007

Questa baseline and pre-mining ground-water quality investigation 15.—Methods of phase II and III well installation and development and results of well logging, hydraulic testing, and water-level measurements in the Red River Valley, New Mexico, 2002-04

In April 2001, the U.S. Geological Survey and the New Mexico Environment Department began a cooperative study to infer the pre-mining ground-water chemistry at the Molycorp molybdenum mine site in the Red River Valley of north- central New Mexico. This report is one in a series of reports that can be used to determine pre-mining ground-water conditions at the mine site. Weathering of hydrothermally altered bedrock in the study area has resulted in steep, highly erosive, and sparsely vegetated scar areas that are clearly visible from the ground and in aerial photographs. Runoff from intense summer rainfall over tributary drainages containing scar areas can transport large quantities of sediment and form debris fans where these tributaries join the Red River. Twenty-nine observation wells were installed in three phases as part of this study in the Red River Valley and tributary drainages. Eight Phase II observation wells were drilled using an air-rotary/hammer rig. Three Phase II and 10 phase III small-diameter wells were installed using a direct-push rig. Lithologic logs were recorded for all eight Phase II drilled wells. Borehole geophysical logging (including natural gamma, induction, and single-detector neutron) was conducted in three Phase II wells. Aquifer tests conducted during 2003 to estimate the hydraulic properties of debris-flow and Red River alluvial deposits in and near Straight Creek included a flow-meter survey, slug tests, and a pumping test. Results of a flow-meter survey in well SC-7A indicated that about 77 percent of the water entered the well from a 10-foot-thick zone near the top of the screened interval and about 23 percent of the water entered the well from a 15-foot-thick zone near the bottom of the screened interval. Slug tests, performed in 11 wells during June 3-5, 2003, indicated that the mean and median estimated hydraulic conductivities for debris-flow deposits were 15.25 and 15.35 feet per day, respectively, for bedrock were 0.12 and 0.08 feet per day, respectively, and for mixed debris flow and Red River alluvium were 73-207 (estimated range) and 80 feet per day. In general, bedrock has the smallest hydraulic conductivity, debris-flow material has the next highest hydraulic conductivity, and mixed debris flow and Red River alluvium has the largest hydraulic conductivity. A pumping test conducted December 3-4, 2003, using well AWWT-1 as the pumped well, and wells AWWT-2, SC-5A, SC-5B, SC-7A, and SC-8A as observation wells, indicated estimated transmissivity of 12,000 to 34,000 feet squared per day and estimated hydraulic conductivity of 230 to 340 feet per day. Water-level measurements in wells SC-6A, SC-7A, SC-8A, and the Hottentot, Hansen, and La Bobita wells show that water levels typically rose rapidly during melting of the winter snowpack in the springtime and then generally declined during the rest of the year. The water-level rise in response to spring snowmelt occurred earlier and was smaller at larger distances from the Red River. Differences between the stage in the Red River and water levels in wells SC-8A and SC-9A, and the absence of water in well SC-9A at the time of well completion, indicate that the Red River has a poor hydraulic connection to the underlying ground-water system and the surface-water system is perched above the ground-water system at this site. Water levels in Phase III wells indicate that the Red River and the shallow ground-water system are connected hydraulically from near wells 4-1D and 4-1S downstream to near wells 2-1 and 2-2 but are poorly connected near the La Bobita well and well 1.

New Mexico↗

USGS2008

Predevelopment Water-Level Contours for Aquifers in the Rainier Mesa and Shoshone Mountain area of the Nevada Test Site, Nye County, Nevada

Contaminants introduced into the subsurface of the Nevada Test Site at Rainier Mesa and Shoshone Mountain by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. Although contaminants were introduced into low-permeability rocks above the regional flow system, the potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by ground-water transport. The primary hydrologic control on this transport is evaluated and examined through a series of contour maps developed to represent the water-level distribution within each of the major aquifers underlying the area. Aquifers were identified and their extents delineated by merging and analyzing multiple hydrostratigraphic framework models developed by other investigators from existing geologic information. The contoured water-level distribution in each major aquifer was developed from a detailed evaluation and assessment of available water-level measurements. Multiple spreadsheets that accompany this report provide pertinent water-level and geologic data by well or drill hole. Aquifers are mapped, presented, and discussed in general terms as being one of three aquifer types?volcanic aquifer, upper carbonate aquifer, or lower carbonate aquifer. Each of these aquifer types was subdivided and mapped as independent continuous and isolated aquifers, based on the continuity of its component rock. Ground-water flow directions, as related to the transport of test-generated contaminants, were developed from water-level contours and are presented and discussed for each of the continuous aquifers. Contoured water-level altitudes vary across the study area and range from more than 5,000 feet in the volcanic aquifer beneath a recharge area in the northern part of the study area to less than 2,450 feet in the lower carbonate aquifer in the southern part of the study area. Variations in water-level altitudes within any single continuous aquifer range from a few hundred feet in a lower carbonate aquifer to just more than 1,100 feet in a volcanic aquifer. Flow directions throughout the study area are dominantly southward with minor eastward or westward deviations. Primary exceptions are westward flow in the northern part of the volcanic aquifer and eastward flow in the eastern part of the lower carbonate aquifer. Northward flow in the upper and lower carbonate aquifers in the northern part of the study area is possible but cannot be substantiated because data are lacking. Interflow between continuous aquifers is evaluated and mapped to define major flow paths. These flow paths delineate tributary flow systems, which converge to form the regional ground-water flow system. The implications of these tributary flow paths in controlling transport away from the underground test areas at Rainier Mesa and Shoshone Mountain are discussed. The obvious data gaps contributing to uncertainties in the delineation of aquifers and development of water-level contours are identified and evaluated.

Scientific Investigations Report↗

USGS2015

Geophysical log analysis of selected test and residential wells at the Shenandoah Road National Superfund Site, East Fishkill, Dutchess County, New York

The U.S. Geological Survey collected and analyzed geophysical logs from 20 test wells and 23 residential wells at the Shenandoah Road National Superfund Site in East Fishkill, New York, from 2006 through 2010 as part of an Interagency Agreement to provide hydrogeologic technical support to the U.S. Environmental Protection Agency, Region 2. The geophysical logs collected include caliper, gamma, acoustic and optical televiewer, deviation, electromagnetic-induction, magnetic-susceptibility, fluid-property, and flow under ambient and pumped conditions. The geophysical logs were analyzed along with single-well aquifer test data and drilling logs to characterize the lithology, fabric, fractures, and flow zones penetrated by the wells. The results of the geophysical log analysis were used as part of the hydrogeologic characterization of the site and in the design of discrete-zone monitoring installations in the test wells and selected residential wells. Most of the logged test and residential wells penetrated gneiss of the Hudson Highlands Complex or dolostones in the Wappinger Group, and some wells penetrated both the dolostone and gneiss. The bedrock fabric reflects the regional northeast-southwest structural trend, as well as localized folding, and includes foliation in the gneiss and bedding in the dolostone. Many fractures were oriented along the bedrock fabric, whereas others were orthogonal to the fabric. Total wellbore transmissivity of the wells was estimated from short-term, single-well aquifer test data through the use of the Cooper-Jacob analytical solution. An empirical relation was established to estimate total wellbore transmissivity from specific-capacity data for wells with insufficient transient drawdown measurements. Wellbore transmissivity estimates ranged from 0.36 to 370 feet squared per day (ft 2 /d), whereas specific capacities ranged from 0.03 to 2.1 gallons per minute per foot ((gal/min)/ft). Transmissivity and hydraulic heads of individual fracture zones were estimated from the total wellbore transmissivity and flow logs through use of an analytical model based on the Thiem equation. The model-estimated transmissivity of 95 fracture zones delineated in the 43 wells ranged from 0.25 to 340 ft 2 /d, with a median value of 6.7 ft 2 /d. The difference between model-estimated fracture-zone heads and the composite heads in each well ranged from less 0.01 to more than 10 feet (ft). Flow-log analysis generally provided an order of magnitude estimate for the fracture-zone hydraulic-head difference on the basis of a comparison of estimated and measured values. The geophysical logs and their analyses are available for display and download from the U.S. Geological Survey, New York Water Science Center, online geophysical log archive ( http://ny.water.usgs.gov/maps/geologs/ ) in LAS (Log ASCII Standard), PDF, and WellCad formats.

New York↗

USGS2020

Transmissivity estimated from brief aquifer tests of domestic wells and compared with bedrock lithofacies and position on hillsides in the Appalachian Plateau of New York

Procedures for undertaking and analyzing recovery from aquifer tests of 13 to 132 seconds (described in reports cited herein) were applied to 51 domestic drilled wells that penetrated bedrock outside major valleys in the part of the Appalachian Plateau of New York drained by the Susquehanna River. Transmissivities calculated from these tests ranged over three orders of magnitude in both the Catskill-Cattaraugus lithofacies (shales, mudstones, siltstones, medium to coarse sandstones, pebbly sandstones) and the Chemung-Hamilton lithofacies (shales, mudstones, siltstones, fine to medium sandstones). Median transmissivity values were 0.000425 foot squared per second (36.7 feet squared per day) in the Catskill-Cattaraugus lithofacies and 0.00055 foot squared per second (47.5 feet squared per day) in the Chemung-Hamilton lithofacies. The distributions of transmissivity values within the two lithofacies were likewise similar. The range and median values of transmissivity were also nearly the same on lower and midlevel hillsides and were only slightly greater on a few upper hillsides. Transmissivities estimated from such easily arranged and analyzed tests may be appropriate for estimating groundwater flux under the small gradients that prevail under natural conditions, but not under larger drawdowns and steeper gradients near clusters of domestic wells. Four of the 51 wells tested were also pumped for 10 to 32 minutes; analysis by the Theis recovery method yielded transmissivities consistent with the brief tests for 2 wells, but 7 to 9 times smaller for 2 wells. Transmissivity values estimated by the PICKINGmodel were not significantly different from values estimated by an automated application of the Picking method (PPC-Recovery) at a probability of 95 percent. Transmissivities calculated by either method from data for time intervals of 120 seconds or less may be of limited practical value because they apply only to a small volume of bedrock close to the pumped well.

New York↗

USGS1976

Results of infiltration tests near Scott City, western Kansas

Several types of ring infiltrometers were used to determine infiltration rates in loessial soil near Scott City, Kansas. Test results were evaluated for consistency, and were compared with infiltration rates in the underlying loess and with hydraulic conductivities in the unsaturated zone. Average daily infiltration rates in the Richfield soil ranged from 3 to 5 feet or 0.9 to 1.5 m (metres) after 16 days using 22-inch or 560mm (millimetre) ring infiltrometers; 2.3 feet (0.7 m) after 68 days using a 10-inch (250-mm) ring infiltrometer; and from 1.3 to 2.2 feet (0.4 to 0.7 m) after 38 days using double-ring infiltrometers. By comparison, the average daily infiltration rate in the underlying Peoria Loess using a 10-inch (250-mm) ring infiltrometer was about 13 feet (4.0 m) after 7 days. Tests using the double-ring infiltrometer, a paraffin seal in the 22-inch (560-mm) infiltrometer, and the measurement of flow through concentric areas of the soil core indicated that leakage of water between the infiltrometer wall and the soil was not significant. Lateral movement of the wetting front extended radially 4.7 feet (1.4 m) from the infiltrometer wall. Laboratory tests of a soil core indicated that the lowest hydraulic conductivity was in the depth interval from 3.9 to 8.6 inches (99 to 218 mm). Soil in this interval, which coincides with the depth of cultivation, evidently limits the rate of infiltration. Air-permeability tests in the unsaturated deposits gave a hydraulic conductivity of 0.2 foot per day (0.1 m/day) for the depth interval from 57 to 75 feet (17.0 to 23.0 m) as compared to a hydraulic conductivity of 1.9 feet per day (0.6 m/day) for the depth interval from 0 to 5 feet (0 to 1.5 m). A perched water table probably would occur above this interval during prolonged infiltration. Infiltration rates determined from the different types of ring infiltrometers were not consistent, but the tests showed that substantial quantities of water could infiltrate the Richfield soil.

Kansas↗

USGS1982

Results of hydrologic tests and water-chemistry analyses, wells H-5A, H-5B, and H-5C, at the proposed Waste Isolation Pilot Plant site, southeastern New Mexico

Data were collected during hydrologic testing at wells H-5A, H-5B, and H-5C in the northeastern part of the proposed Waste Isolation Pilot Plant site in southeastern New Mexico. The three water-bearing zones tested, the Magenta and Culebra Dolomite Members of the Rustler Formation and the Rustler Formation-Salado Formation contact, yield water to wells at rates less than 0.6 gallon per minute. Throughout the testing, water-pressure response in the tested zone was monitored by a pressure-transducer system. Shut-in and slug tests were conducted to acquire data from which the following values were derived. Dissolved-solids concentrations In water samples were: (1) Magenta Dolomite Member, 6,090 milligrams per liter; (2) Culebra Dolomite Member, 144,000 milligrams per liter; and (3) Rustler Formation-Salado Formation contact, 412,000 milligrams per liter. The major chemical constituents of water samples from the Magenta Dolomite Member were sodium and sulfate; from the Culebra Dolomite Member, sodium and chloride; and from the Rustler Formation-Salado Formation contact, magnesium and chloride. Radium-226, a naturally occurring radioactive element, was present in samples from all three zones.

New Mexico↗

USGS1984

Geohydrology of volcanic tuff penetrated by test well UE-25b#1, Yucca Mountain, Nye County, Nevada

Test well UE-25bNo1, located on the east side of Yucca Mountain in the southwestern part of the Nevada Test Site, was drilled to a total depth of 1,220 meters and hydraulically tested as part of a program to evaluate the suitability of Yucca Mountain as a nuclear-waste repository. The well penetrated almost 46 meters of alluvium and 1,174 meters of Tertiary volcanic tuffs. The composite hydraulic head for aquifers penetrated by the well was 728.9 meters above sea level (471.4 meters below land surface) with a slight decrease in loss of hydraulic head with depth. Average hydraulic conductivities for stratigraphic units determined from pumping tests, borehole-flow surveys, and packer-injection tests ranged from less than 0.001 meter per day for the Tram Member of the Crater Flat Tuff to 1.1 meters per day for the Bullfrog Member of the Crater Flat Tuff. The small values represented matrix permeability of unfractured rock; the large values probably resulted from fracture permeability. Chemical analyses indicated that the water is a soft sodium bicarbonate type, slightly alkaline, with large concentrations of dissolved silica and sulfate. Uncorrected carbon-14 age dates of the water were 14,100 and 13,400 years. (USGS)

Water-Resources Investigations Report↗

USGS1986

Hydraulic properties of rock units and chemical quality of water for INEL-1 — A 10,365-foot deep test hole drilled at the Idaho National Engineering Laboratory, Idaho

A 10,365-ft deep test hole drilled at the INEL (Idaho National Engineering Laboratory) in southeastern Idaho provided hydraulic information for rock units underlying the Snake River Plain aquifer. Four aquifer tests showed that the hydraulic conductivity decreased with depth--from an average of 0.03 ft/day for the interval from 1,511 to 2,206 ft below land surface to an average of 0.002 ft/day for the interval from 4 ,210 to 10,365 ft. In contrast the hydraulic conductivity of the Snake River Plain aquifer ranges from 1 to 100 ft/day. The hydraulic head increased with depth; the head at depth was about 115 ft greater than that for the Snake River Plain aquifer. Water temperature in the test hole increased from 26 C at 600 ft below land surface to 146 C at 9,985 ft. The gradient was nearly linear and averaged about 1.3 C/100 ft of depth. Water from the Snake River Plain aquifer contained 381 mg/L of dissolved solids and had a calcium bicarbonate chemical composition. The dissolved solids concentration in underlying rock units ranged from 350 to 1,020 mg/L and the water had a sodium bicarbonate composition. Hydrologic data for the test hole suggest that the effective base of the Snake River Plain aquifer near the test hole is between 840 and 1,220 ft below land surface. The upward vertical movement of water into the Snake River Plain aquifer from underlying rock units could be on the order of 15,000 acre-ft/year at INEL. (Author 's abstract)

Idaho↗

USGS1995

Hydrogeology and results of tracer tests at the old Tampa well field in Hillsborough County, with implications for wellhead-protection strategies in west-central Florida

Wellhead-protection strategies were evaluated for the Upper Floridan aquifer of west-central Florida using the old Tampa well field in northeastern Hillsborough County, Florida, as a test site. The upper 400 feet of the Upper Floridan aquifer responded to pumping as an equivalent, porous medium for a range of discharge rates from 450 to 1,000 gallons per minute. Transmissivity and storage coefficient values determined for the Upper Floridan aquifer were 23,000 feet squared per day and 0.0001, respectively. Rock cores from the Upper Floridan aquifer have effective porosity values from 21 to 46 percent. Tracer tests were conducted using a fluorescent dye. A bimodal distribution of tracer arrival times indicates ground-water flow through a dual porosity system. Analysis of tracer test results an effective porosity of 25 percent and a longitudinal dispersivity of 1.3 feet for the aquifer matrix. A numerical aquifer-simulation equivalent porous media model of the Upper Floridan aquifer was calibrated using results of aquifer tests. A particle-tracking program was used to simulate the matrix flow groundwater travel time measured with the fluorescent dye tracer test. An evaluation of wellhead-protection strategies was conducted using the particle-tracking program to simulate areas of contribution from the aquifer matrix. The results of this study demonstrate the heterogeneity of the Upper Floridan aquifer. Because of this heterogeneity, the use of uniform porosity models to delineate time-related areas of wellhead protection in the karst Upper Floridan aquifer is inappropriate; however, ground-water movement in the aquifer matrix can be simulated with uniform porosity models.

Water-Resources Investigations Report↗

USGS1996

Results of ground-water tracer tests using tritiated water at Oak Ridge National Laboratory, Tennessee

Ground-water tracer tests were conducted at two sites in the radioactive-waste disposal area of Oak Ridge National Laboratory from 1977 to 1982. The purpose of the tests was to determine if the regolith beds had weathered sufficiently to permit the substantial flow of water across them. Regolith of the sites has developed on the Pumpkin Valley Shale and the Nolichucky Shale of the Conasauga Group, both of Cambrian age. About 50 curies of tritium dissolved in water were used as the tracer at one site, and about 100 curies at the other. Distances from the injection wells to a semi-circle of observation wells were 12 and 30 feet, respectively. Results demonstrated that ground water is able to flow through joints in the weathered bedding and that the direction of the water-table gradient is the primary factor governing flow direction. Nevertheless, the substantial lateral spread of the plume as it developed showed that bedding-plane openings, important in controlling flow in the deeper rock, can still exert a significant secondary influence on flow direction in the weathered rock. About 3,500 water samples from the injection and observation wells were analyzed for tritium during the test period. Concentrations detected spanned 11 orders of magnitude. Measurable concentrations were still present in the two injection wells and most observation wells 5 years after the tracer was introduced. Matrix diffusion may have played a significant role in these tests. The process would account for the sustained concentrations of tritium at many of the observation wells, the long-term residual concentrations at the injection and observation wells, and the apparent slow movement of the centers of mass across the two well fields. The process also would have implications regarding aquifer remediation. Other tracer tests have been conducted in the regolith of the Conasauga Group. Results differ from the results described in this report.

Tennessee↗

USGS2001

Copper avoidance and mortality of juvenile brown trout ( Salmo trutta ) in tests with copper-sulfate-treated water from West Branch Reservoir, Putnam County, New York

Copper-avoidance tests and acute-toxicity (mortality) tests on hatchery-reared, young-of- the-year brown trout ( salmo trutta ) were conducted with water from West Branch Reservoir to assess the avoidance response to copper sulfate treatment, which is used occasionally by New York City Department of Environmental Protection to decrease phytoplankton populations in the reservoir. Avoidance-test results indicate that juvenile brown trout tend to avoid dissolved copper concentrations greater than about 55 μg/L (micrograms per liter), which is the approximate avoidance-response threshold. The mean net avoidance response of brown trout to dissolved copper concentrations of 70 and 100 μg/L, and possibly 80 μg/L, was significantly different (at α= 0.1) from the mean net avoidance response of fish to control (untreated) water and to treated water at most other tested concentrations. Mortality-test results indicate that the 96-hr median lethal concentration (LC 50 ) of dissolved copper was 61.5 μg/L. All (100 percent) of the brown trout died at a dissolved copper concentration of 85 μg/L, many died at concentrations of 62 μg/L and 70 μg/L, and none died in the control waters (7 μg/L) or at concentrations of 10, 20, or 45 μg/L. The estimated concentration of dissolved copper that caused fish mortality (threshold) was 53.5 μg/L, virtually equivalent to the avoidance-response threshold. Additional factors that could affect the copper-avoidance and mortality response of individual brown trout and their populations in West Branch Reservoir include seasonal variations in certain water-quality parameters, copper-treatment regimes, natural fish distributions during treatment, and increased tolerance due to acclimation. These warrant additional study before the findings from this study can be used to predict the effects that copper sulfate treatments have on resident fish populations in New York City reservoirs.

New York↗

USGS1985

Simulation of an aquifer test on the Tesuque Pueblo Grant, New Mexico

An aquifer test was designed and conducted in the anisotropic dipping beds of the Tesuque Formation on the Tesuque Pueblo Grant, New Mexico. The three-dimensional digital model used to analyze the test approximated the response to the test. The analysis of the geohydrology of the test site in combination with the model calibration has provided estimates of average aquifer characteristics for the group of beds penetrated at the test site; the hydraulic conductivity parallel to the beds is about 2 feet per day, the hydraulic conductivity normal to the beds is about 0.0001 foot per day or lower, the specific yield is about 0.15, and the specific storage is about 2 x 10 -6 per foot.

Water Supply Paper↗