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At least 217 records · Page 12Linked to original sources
USGS2009

Detailed Geophysical Fault Characterization in Yucca Flat, Nevada Test Site, Nevada

Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada. Between the years 1951 and 1992, 659 underground nuclear tests took place in Yucca Flat; most were conducted in large, vertical excavations that penetrated alluvium and the underlying Cenozoic volcanic rocks. Radioactive and other potential chemical contaminants at the NTS are the subject of a long-term program of investigation and remediation by the U.S. Department of Energy (DOE), National Nuclear Security Administration, Nevada Site Office, under its Environmental Restoration Program. As part of the program, the DOE seeks to assess the extent of contamination and to evaluate the potential risks to humans and the environment from byproducts of weapons testing. To accomplish this objective, the DOE Environmental Restoration Program is constructing and calibrating a ground-water flow model to predict hydrologic flow in Yucca Flat as part of an effort to quantify the subsurface hydrology of the Nevada Test Site. A necessary part of calibrating and evaluating a model of the flow system is an understanding of the location and characteristics of faults that may influence ground-water flow. In addition, knowledge of fault-zone architecture and physical properties is a fundamental component of the containment of the contamination from underground nuclear tests, should such testing ever resume at the Nevada Test Site. The goal of the present investigation is to develop a detailed understanding of the geometry and physical properties of fault zones in Yucca Flat. This study was designed to investigate faults in greater detail and to characterize fault geometry, the presence of fault splays, and the fault-zone width. Integrated geological and geophysical studies have been designed and implemented to work toward this goal. This report describes the geophysical surveys conducted near two drill holes in Yucca Flat, the data analyses performed, and the integrated interpretations developed from the suite of geophysical methodologies utilized in this investigation. Data collection for this activity started in the spring of 2005 and continued into 2006. A suite of electrical geophysical surveys were run in combination with ground magnetic surveys; these surveys resulted in high-resolution subsurface data that portray subsurface fault geometry at the two sites and have identified structures not readily apparent from surface geologic mapping, potential field geophysical data, or surface effects fracture maps.

Open-File Report↗
USGS2015

Depth-dependent groundwater quality sampling at City of Tallahassee test well 32, Leon County, Florida, 2013

Public-supply wells sometimes produce water of less than desirable quality because contaminants can migrate to the open interval of wells through preferential pathways. If these pathways can be identified, zones that produce poor quality water can be excluded during the well-construction process. The U.S. Geological Survey has developed geophysical testing methods that can be used to delineate zones of high permeability in test wells. Once the highly permeable zones are identified, water-quality data can be collected from each zone to identify whether any of the zones produce water of poor quality. The zones producing poor quality water can then be cased off in the final well design so that they do not contribute flow to the production well, reducing subsequent water-treatment costs. A test well was drilled by the City of Tallahassee to assess the suitability of the site for the installation of a new well for public water supply. The test well is in Leon County in north-central Florida. The U.S. Geological Survey delineated high-permeability zones in the Upper Floridan aquifer, using borehole-geophysical data collected from the open interval of the test well. A composite water sample was collected from the open interval during high-flow conditions, and three discrete water samples were collected from specified depth intervals within the test well during low-flow conditions. Water-quality, source tracer, and age-dating results indicate that the open interval of the test well produces water of consistently high quality throughout its length. The cavernous nature of the open interval makes it likely that the highly permeable zones are interconnected in the aquifer by secondary porosity features.

Florida↗
USGS1962

Aquifer-test compilation for the San Joaquin Valley, California

This report is the first of a series the purpose of which is to make available in standard tabular form the results of aquifer tests that have been made by various private and public agencies in California. The scope of the compilation is to describe systematically, in a form agreed upon by the California Department of Water Resources and the Geological Survey, the (1) test location, (2) pumping data, (3) well data, and (4) summary of results. The results of these tests sometimes have been published but most frequently have been used only as a step in obtaining other information, consequently the results and even the location of aquifer tests have not been readily available. This report has been prepared by the Geological Survey under the immediate supervision of Fred Kunkel, district geologist for California, in cooperation with the California Department of Water Resources, and tabulates through October 1962 all tests analyzed by the Geological Survey for the San Joaquin Valley. The report is designed to be expanded when additional tests are analyzed or new tests are made.

California↗
USGS1979

Preliminary data for Madison Limestone test well 3, NW 1/4 Sec. 35. T. 2 N., R. 27 E., Yellowstone County, Montana

This report provides preliminary data for Madison Limestone test well 3 in Yellowstone County, Mont., including test-well history , geology of the test well, hydrologic testing, and geochemistry. It also discusses the preliminary results and future testing. The test well was drilled as part of the study to determine the water-resource potential of the Madison Limestone and associated rocks to meet future water needs in a 188,000-square-mile region that includes the coal-rich area of the Northern Great Plains. Drilling and testing were designed to yield a maximum of stratigraphic, structural, geophysical, and hydrologic information. (Woodard-USGS)

Open-File Report↗
USGS1985

Selected test-well data from the MX-missile siting study, Tooele, Juab, Millard, Beaver, and Iron Counties, Utah

This report contains well data collected from 1979 to 1983 in a part of the Great Basin in western Utah (fig. 1). The area is characterized by a series of generally north-trending mountain ranges separated by alluviumfilled basins that are partially filled with sedimentary deposits eroded from the adjacent mountains and lacustrine sediments deposited by Lake Bonneville. Most of the intermountain basins are elongated in the northward direction, but some are almost equidimensional. This report was prepared as part of the Great Basin Regional AquiferSystem Analysis (RASA) program. The report is intended to make well data from the MX-missile siting study readily available to water-resource managers and the general public. It includes well data obtained in areas for which little or no such data have been published previously. Well-drilling and well-completion data were compiled by Ertec, Inc. (formerly Fugro National, Inc.) under contract with the U. S. Air Force. Those data along with aquifer test data, geophysical logs, and drillers1 or geologists1 logs were obtained from Ertec, Inc. under an agreement with the U.S. Air Force. The authors thank the officials of both Ertec, Inc. and the U.S. Air Force for their helpful cooperation. The U.S. Geological Survey obtained accurate locations of the test wells (pi. 1) and accurate water-level measurements in those wells (table 1). Chemical analyses of water samples collected from several of the test wells drilled in the Sevier Desert have been published in a report by Enright and Holmes (1982, table 5). Test drilling for the MX-missile siting study consisted of two parts, the verification phase and the water-resources phase. The verification jhase was designed to obtain information necessary for the design and construction of the MX-basing system. Numerous small diameter wells were bored with depths ranging from 92 to 205 feet. Two-inch diameter JVC casing with the bottom 20 feet perforated was installed in each borehole. The water-resources phase was designed to determine ground-water availibility and to estimate the effects of ground-water withdrawals required for the construction of the MX-basing system. Six large-diameter production test wells were drilled along with associated small-diameter observation wells. Depths ranged from 310 to 1,399 feet. Lithologic logs for selected production test wells or associated observation wells are listed in table 2. Geophysical logs and aquifer test data are available in the files of the U. S. Geological Survey, as indicated in table 1.

Utah↗
USGS1992

Geologic and hydrologic data collected at test holes NC-4 and NC-14, Manati and Vega Baja, Puerto Rico

Test holes NC-4 and NC-14 were drilled in the municipalities of Manati and Vega Baja, respectively, in northern Puerto Rico as part of a study of the ground-water resources in the Northern Coastal Province of Puerto Rico. This study was conducted from 1986 to 1988 by the U.S. Geological Survey in cooperation with the Puerto Rico Department of Natural Resources. Test holes NC-4 and NC-14 were drilled to depths of 1,898 and 1,837 feet below land surface, respectively. Geologic and hydrologic data collected during drilling included continuous core lithology, water-quality measurements, water levels, and estimates of aquifer yields from the water-bearing zones. Detailed petrological and microfaunal analyses of the cores were used to determine the mineralogical content, ages, and paleoenvironments of deposition. Analysis of the core recovered from test hole NC-4 indicated that four geologic formations of middle Tertiary age were penetrated, these were in descending order: the Aymam6n Limestone, the Los Puertos Limestone, the Cibao Formation, and the Lares Limestone. The Tertiary formations are capped by surficial deposits of Quaternary age. Test hole NC-14 penetrated rocks of middle Tertiary age that included three geologic formations, these were in descending order: the AymamOn Limestone, the Los Puertos Limestone, and the Cibao Formation. These formations are overlain by surficial deposits of Quaternary age. In both test holes the Cibao Formation consisted of the undifferentiated Quebrada Arenas and the Rio Indio Limestone Members of the Cibao Formation and an unnamed mudstone unit. Test hole NC-4 penetrated three water-bearing units: a water-table aquifer and two artesian aquifers. The specific conductance in the water-table aquifer ranged from 500 to 38,000 microsiemens per centimeter at 25 degrees Celsius. The specific conductance ranged from 740 to 800 microsiemens per centimeter at 25 degrees Celsius in the two artesian aquifers. The relative yield ranged from 120 to 195 gallons per minute in the water-table aquifer and from 60 to 195 gallons per minute in the artesian aquifers. The water level ranged from 81 to 89 feet below land surface in the water-table aquifer. In the artesian aquifers, water levels ranged from 22 feet below land surface to 88 feet above land surface. Test hole NC-14 penetrated four water-bearing units: a water-table aquifer and three artesian aquifers. The specific conductance in the water-table aquifer ranged from 590 microsiemens per centimeter at 25 degrees Celsius at a depth of 40 feet to 49,500 microsiemens per centimeter at 25 degrees Celsius at 1,010 feet below land surface. In the artesian aquifers specific conductance was about 700 microsiemens per centimeter at 25 degrees Celsius. The relative yield ranged from 58 to 370 gallons per minute in the water-table aquifer, and from 15 to 60 gallons per minute in the artesian aquifers. The water level in the water table aquifer ranged from 20 to 32 feet below land surface. In the artesian aquifers the water levels ranged from 18 feet below land surface to 19 feet above land surface.

Open-File Report↗
USGS1906

Report on the operations of the coal-testing plant of the United States Geological Survey at the Louisiana Purchase Exposition, Saint Louis, Missouri, 1904: Part I.--Field work, classification of coals, chemical work

The authority for conducting at the Louisiana Purchase Exposition an investigation of the coals and lignites of the United States is contained in the act of Congress providing for the urgent deficiencies in the appropriations for the fiscal year 1905, and approved February 18, 1904, as follows: For analyzing and testing. at the Louisiana Purchase Exposition the coals and lignites of the United States, in order to determine their fuel values mid the most economical method for their utilization for different purposes, under the supervision of the Director of the United States Geological Survey, thirty thousand dollars, to be available until expended: Provided, That all testing machinery and all coals and lignites to be tested shall be contributed without charge to the Government. In the general deficiency bill approved April 27, 1904, an additional appropriation of $30,000 was provided, making the total sum appropriated for this work $60,000. For carrying out the provisions of these acts the Director of the Geological Survey appointed a committee, consisting of Edward W. Parker, Joseph A. Holmes, and Marius R. Campbell, to direct the construction and operation of the plant. It will be observed that under the law authorizing this work all of the testing machinery and all of the coals to be tested had to be furnished to the Government free of charge. Under these conditions it was not possible to equip an ideal testing plant, and the assembling and construction of such equipment as conld be obtained under these provisions entailed some annoying delays in the completion of the plant. In addition to this, the delivery of a considerable quantity of operating and conveying apparatus purchased from the Link Belt Machinery Company, of Chicago, was delayed by a strike in the works of that company. As a result of these combined influences the plant was not put in operation until the 1st of September. Notwithstanding these delays, the committee feels that through the hearty and patriotic cooperation of a large number of manufacturers of apparatus and machinery it was able to collect and install, within a notably short time, a testing plant that was well suited for such pioneer work.

Missouri↗
USGS2008

Geophysical Logs, Aquifer Tests, and Water Levels in Wells in and Near the North Penn Area 7 Superfund Site, Upper Gwynedd Township, Montgomery County, Pennsylvania, 2002-2006

Ground water in the vicinity of several industrial facilities in Upper Gwynedd Township and Lansdale Borough, Montgomery County, Pa., is contaminated with several volatile organic compounds (VOCs). The 2-square-mile area was placed on the National Priorities List as the North Penn Area 7 Superfund Site by the U.S. Environmental Protection Agency (USEPA) in 1989. The U.S. Geological Survey (USGS) conducted geophysical logging, aquifer testing, water-level monitoring, and streamflow measurements in the vicinity of North Penn Area 7 from October 2002 through December 2006. This followed work that began in 2000 to assist the USEPA in developing an understanding of the hydrogeologic framework in the area as part of the USEPA Remedial Investigation. The study area is underlain by Triassic- and Jurassic-age sandstones, siltstones, and shales of the Lockatong Formation and the Brunswick Group. Regionally, these rocks strike northeast and dip to the northwest. The sequence of rocks form fractured-rock aquifers that act as a set of confined to semi-confined layered aquifers of differing permeabilities. The aquifers are recharged by precipitation and discharge to streams and wells. The Wissahickon Creek headwaters are less than 1 mile northeast of the study area. This stream flows southwest approximately parallel to strike and bisects North Penn Area 7. Ground water is pumped in the vicinity of North Penn Area 7 for industrial use and public supply. The USGS collected geophysical logs for 42 wells that ranged in depth from 40 to 477 ft. Aquifer-interval-isolation testing was done in 17 of the 42 wells, for a total of 122 zones tested. A multiple-well aquifer test was conducted by monitoring the response of 14 wells to pumping and shutdown of a 600-ft deep production well in November-December 2004. In addition, water levels were monitored continuously in four wells in the area from October 2002 through September 2006, and streamflow was measured quarterly at two sites on Wissahickon Creek from December 2002 through September 2005. Geophysical logging identified water-bearing zones associated with high-angle fractures and bedding-plane openings throughout the depth of the boreholes. Heatpulse-flowmeter measurements under non-pumping, ambient conditions in 16 wells greater than 200 ft in depth indicated that borehole flow, where detected, was only upward in 2 wells and only downward in 5 wells. In nine wells, both upward and downward flow were measured. Geologic structure and pumping in the area affect the spatial distribution of vertical gradients. Heatpulse-flowmeter measurements under pumping conditions were used to identify the most productive intervals in wells. Correlation of natural-gamma-ray logs indicated bedding in the area probably strikes about 45 to 65 degrees northeast and dips about 9 degrees northwest. Aquifer intervals isolated by inflatable packers in 17 wells were pumped to test productivity of water-bearing zones and to collect samples to determine chemical quality of water produced from the interval. Interval-isolation testing confirmed the vertical hydraulic gradients indicated by heatpulse-flowmeter measurements. The specific capacities of the 122 isolated intervals ranged over about three orders of magnitude, from 0.01 to 10.6 gallons per minute per foot, corresponding to calculated transmissivities of 1.2 to 2,290 feet squared per day. Intervals adjacent to isolated pumped intervals commonly showed little response to pumping of the isolated zone. The presence of vertical hydraulic gradients and lack of adjacent-interval response to pumping in isolated intervals indicate a limited degree of vertical hydraulic connection between the aquifer sections tested. Differences were apparent in inorganic water quality of water from isolated intervals, including pH, specific conductance, and dissolved oxygen. Concentrations of most VOC contaminants in most wells with predominantly upward vertical gradients were g

Scientific Investigations Report↗
USGS2018

Completion summary for borehole TAN-2312 at Test Area North, Idaho National Laboratory, Idaho

In 2017, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, drilled and constructed borehole TAN-2312 for stratigraphic framework analyses and long-term groundwater monitoring of the eastern Snake River Plain aquifer at the Idaho National Laboratory in southeast Idaho. The location of borehole TAN-2312 was selected because it was downgradient from TAN and believed to be the outer extent of waste plumes originating from the TAN facility. Borehole TAN-2312 initially was cored to collect continuous geologic data, and then re-drilled to complete construction as a monitor well. The final construction for borehole TAN-2312 required 16- and 10-inch (in.) diameter carbon-steel well casing to 37 and 228 feet below land surface (ft BLS), respectively, and 9.9-in. diameter open-hole completion below the casing to 522 ft BLS. Depth to water is measured near 244 ft BLS. Following construction and data collection, a temporary submersible pump and water-level access line were placed near 340 ft BLS to allow for aquifer testing, for collecting periodic water samples, and for measuring water levels. Borehole TAN-2312 was cored continuously, starting at the first basalt contact (about 37 ft BLS) to a depth of 568 ft BLS. Not including surface sediment (0–37 ft), recovery of basalt and sediment core at borehole TAN-2312 was about 93 percent; however, core recovery from 170 to 568 ft BLS was 100 percent. Based on visual inspection of core and geophysical data, basalt examined from 37 to 568 ft BLS consists of about 32 basalt flows that range from approximately 3 to 87 ft in thickness and 4 sediment layers with a combined thickness of approximately 76 ft. About 2 ft of total sediment was described for the saturated zone, observed from 244 to 568 ft BLS, near 296 and 481 ft BLS. Sediment described for the saturated zone were composed of fine-grained sand and silt with a lesser amount of clay. Basalt texture for borehole TAN-2312 generally was described as aphanitic, phaneritic, and porphyritic. Basalt flows varied from highly fractured to dense with high to low vesiculation. Geophysical and borehole video logs were collected after core drilling and after final construction at borehole TAN-2312. Geophysical logs were examined synergistically with available core material to suggest zones where groundwater flow was anticipated. Natural gamma log measurements were used to assess sediment layer thickness and location. Neutron and gamma-gamma source logs were used to identify fractured areas for aquifer testing. Acoustic televiewer logs, fluid logs, and electromagnetic flow meter results were used to identify fractures and assess groundwater movement when compared against neutron measurements. Furthermore, gyroscopic deviation measurements were used to measure horizontal and vertical displacement for borehole TAN-2312. After construction of borehole TAN-2312, a single-well aquifer test was completed September 27, 2017, to provide estimates of transmissivity and hydraulic conductivity. Estimates for transmissivity and hydraulic conductivity were 1.51×102 feet squared per day and 0.23 feet per day, respectively. During the 220-minute aquifer test, well TAN-2312 had about 23 ft of measured drawdown at sustained pumping rate of 27.2 gallons per minute. The transmissivity and hydraulic conductivity estimates for well TAN-2312 were lower than the values determined from previous aquifer tests in other wells near Test Area North. Water samples were analyzed for cations, anions, metals, nutrients, volatile organic compounds, stable isotopes, and radionuclides. Water samples for most of the inorganic constituents showed concentrations near background levels for eastern regional groundwater. Water samples for stable isotopes of oxygen, hydrogen, and sulfur indicated some possible influence of irrigation on the water quality. The volatile organic compound data indicated that this well had some minor influence by wastewater disposal practices at Test Area North.

Idaho↗
USGS2003

Aquifer tests and simulation of ground-water flow in Triassic sedimentary rocks near Colmar, Bucks and Montgomery Counties, Pennsylvania

This report presents the results of a study by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency to evaluate ground-water flow in Triassic sedimentary rocks near Colmar, in Bucks and Montgomery Counties, Pa. The study was conducted to help the U.S. Environmental Protection Agency evaluate remediation alternatives at the North Penn Area 5 Superfund Site near Colmar, where ground water has been contaminated by volatile organic solvents (primarily trichloroethene). The investigation focused on determining the (1) drawdown caused by separately pumping North PennWater Authority wells NP–21 and NP–87, (2) probable paths of groundwater movement under present-day (2000) conditions (with NP–21 discontinued), and (3) areas contributing recharge to wells if pumping from wells NP-21 or NP–87 were restarted and new recovery wells were installed. Drawdown was calculated from water levels measured in observation wells during aquifer tests of NP–21 and NP–87. The direction of ground-water flow was estimated by use of a three-dimensional ground-water-flow model. Aquifer tests were conducted by pumping NP–21 for about 7 days at 257 gallons per minute in June 2000 and NP–87 for 3 days at 402 gallons per minute in May 2002. Drawdown was measured in 45 observation wells during the NP–21 test and 35 observation wells during the NP–87 test. Drawdown in observation wells ranged from 0 to 6.8 feet at the end of the NP–21 test and 0.5 to 12 feet at the end of the NP–87 test. The aquifer tests showed that ground-water levels declined mostly in observation wells that were completed in the geologic units penetrated by the pumped wells. Because the geologic units dip about 27 degrees to the northwest, shallow wells up dip to the southeast of the pumped well showed a good hydraulic connection to the geologic units stressed by pumping. Most observation wells down dip from the pumping well penetrated units higher in the stratigraphic section that were not well connected to the units stressed by pumping. The best hydraulic connection to the pumped wells was indicated by large drawdown in observation wells that penetrate the water-bearing unit encountered below 400 feet below land surface in wells NP–21 and NP–87. The hydraulic connection between wells NP–21 (or NP–87) and observation wells in the southern area of ground-water contamination near the BAE Systems facility is good because the observation wells probably penetrate this water-bearing unit. A 3-dimensional, finite-difference, groundwater- flow model was used to simulate flow paths and areas contributing recharge to wells for current (2000) conditions of pumping in the Colmar area and for hypothetical situations of pumping suggested by the U.S. Environmental Protection Agency that might be used for remediation. Simulations indicate that under current conditions, ground water in the northern area of contamination near the former Stabilus facility moves to the northwest and discharges mostly to West Branch Neshaminy Creek; in the southern area of contamination near BAE Systems facility, ground water probably moves west and discharges to a tributary of West Branch Neshaminy Creek near well NP–21. Model simulations indicate that if NP–21 or NP–87 are pumped at 400 gallons per minute, groundwater recharge is likely captured from the southern area of contamination, but ground-water recharge from the northern area of contamination is less likely to be captured by the pumping. Simulations also indicate that pumping of a new recovery well near BAE Systems facility at 8 gallons per minute and two new recovery wells near the former Stabilus facility at a total of about 30 gallons per minute probably would capture most of the ground-water recharge in the areas where contamination is greatest.

Water-Resources Investigations Report↗
USGS1986

Selected drill-stem test data for the Upper Colorado River basin

Permeability data from aquifers and confining layers may be available from drill-stem tests made during the course of petroleum exploration. During the drill-stem test, the stratigraphic interval of interest is isolated in the hole by the use of packers attached to the drill string. Fluid flows into the drilling pipe under the influence of the formation head. Pressure measurements and other data collected during the course of the test are used to gain information on undisturbed formation head, permeability, hydraulic conductivity, and fluid temperature. Drill-stem test data for individual formation in the Upper Colorado River Basin presented in tables in this report are arranged in groups of 10 hydrogeologic units that were classified on the basis of geologic age, location, depositional environment and lithology. Maps indicating the locations of test sites and areal distribution of test data within the 10 units are provided at the beginning of each table. Stratigraphic columns also are provided to identify the relative ages of the formation tested and to correlate regional hydrogeologic units. (USGS)

Water-Resources Investigations Report↗
USGS1996

Summary of hydrogeologic controls on ground-water flow at the Nevada Test Site, Nye County, Nevada

The underground testing of nuclear devices has generated substantial volumes of radioactive and other chemical contaminants below ground at the Nevada Test Site (NTS). Many of the more radioactive contaminants are highly toxic and are known to persist in the environment for thousands of years. In response to concerns about potential health hazards, the U.S. Department of Energy, under its Environmental Restoration Program, has made NTS the subject of a long-term investigation. Efforts supported through the U.S. Department of Energy program will assess whether byproducts of underground testing pose a potential hazard to the health and safety of the public and, if necessary, will evaluate and implement steps to remediate any of the identified dangers. Test-generated contaminants have been introduced over large areas and at variable depths above and below the water table throughout NTS. Evaluating the risks associated with these byproducts of underground testing presupposes a knowledge of the source, transport, and potential receptors of these contaminants. Ground-water flow is the primary mechanism by which contaminants can be transported significant distances away from the initial point of injection. Flow paths between contaminant sources and potential receptors are separated by remote areas that span tens of miles. The diversity and structural complexity of the rocks along these flow paths complicates the hydrology of the region. Although the hydrology has been studied in some detail, much still remains uncertain about flow rates and directions through the fractured-rock aquifers that transmit water great distances across this arid region. Unique to the hydrology of NTS are the effects of underground testing, which severely alter local rock characteristics and affect hydrologic conditions throughout the region. Any assessment of the risk must rely in part on the current understanding of ground-water flow, and the assessment will be only as good as the understanding itself. This report summarizes what is known and inferred about ground-water flow throughout the NTS region. The report identifies and updates what is known about some of the major controls on ground-water flow, highlights some of the uncertainties in the current understanding, and prioritizes some of the technical needs as related to the Environmental Restoration Program. An apparent deficiency in the current understanding is a lack of knowledge about flow directions and rates away from major areas of testing. Efforts are necessary to delineate areas of downgradient flow and to identify factors that constrain and control flow within these areas. These efforts also should identify the areas most critical to gaining detailed understanding and to establishing long-term monitoring sites necessary for effective remediation.

Nevada↗
USGS2016

Recommended reporting standards for test accuracy studies of infectious diseases of finfish, amphibians, molluscs and crustaceans: the STRADAS-aquatic checklist

Complete and transparent reporting of key elements of diagnostic accuracy studies for infectious diseases in cultured and wild aquatic animals benefits end-users of these tests, enabling the rational design of surveillance programs, the assessment of test results from clinical cases and comparisons of diagnostic test performance. Based on deficiencies in the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines identified in a prior finfish study (Gardner et al. 2014), we adapted the Standards for Reporting of Animal Diagnostic Accuracy Studies—paratuberculosis (STRADAS-paraTB) checklist of 25 reporting items to increase their relevance to finfish, amphibians, molluscs, and crustaceans and provided examples and explanations for each item. The checklist, known as STRADAS-aquatic, was developed and refined by an expert group of 14 transdisciplinary scientists with experience in test evaluation studies using field and experimental samples, in operation of reference laboratories for aquatic animal pathogens, and in development of international aquatic animal health policy. The main changes to the STRADAS-paraTB checklist were to nomenclature related to the species, the addition of guidelines for experimental challenge studies, and the designation of some items as relevant only to experimental studies and ante-mortem tests. We believe that adoption of these guidelines will improve reporting of primary studies of test accuracy for aquatic animal diseases and facilitate assessment of their fitness-for-purpose. Given the importance of diagnostic tests to underpin the Sanitary and Phytosanitary agreement of the World Trade Organization, the principles outlined in this paper should be applied to other World Organisation for Animal Health (OIE)-relevant species.

Diseases of Aquatic Organisms↗
USGS2019

Gas hydrate production testing – Knowledge gained

Since their initial discovery in the 1960’s, gas hydrates have been considered to be an important potential source of unconventional natural gas. Significant progress has been made relative to our understanding of the geologic and engineering controls on the ultimate energy potential of gas hydrate; however, more work is required to realize the promise of gas hydrates as a future energy source. Gas hydrates have been encountered, recovered or inferred to exist in numerous sedimentary basins in Arctic permafrost settings, regions of alpine permafrost, marine sediments of outer continental margins and in deep lakes. Despite the great abundance of potential gas hydrate resources in the world, a large portion of these resources reside in clay-rich sediments and fracture dominated reservoir systems, and are not generally considered producible with existing technology, but may have future potential with the emergence of new technologies. For a large portion of the world, gas hydrate in sand reservoirs have become a viable production target and the focus of the first production testing efforts. Production tests in Arctic Canada (Mackenzie Delta) and Alaska have shown that gas can be produced from highly-concentrated gas hydrate accumulations in coarse-grained (i.e., sand rich) reservoir systems with conventional production technologies. Production can be achieved through the depressurization method and by more complex methods such as molecular substitution (e.g., CO2-CH4 exchange). In 2013, the gas hydrate production test was conducted in a marine setting in the offshore of Japan. An additional test was conducted in Japan in 2017 to further evaluate alternative well completion technologies. Also in 2018, China initiated a 60-day gas hydrate production test in the Shenhu region of the South China Sea. This report reviews the results of gas hydrate engineering and production testing studies associated with the Mallik, Mount Elbert, and Iġnik Sikumi projects in northern Canada and Alaska. The results of the marine gas hydrate producing testing efforts in the Nankai Trough (Japan) and in the South China Sea (China) are also summarized

Conference Paper↗
USGS1998

Preliminary evaluation of a simple in vitro test for the diagnosis of type C botulism in wild birds

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of type C botulinum toxin ( Clostridium botulinum ) in wild birds. This simple, antigen-capture ELISA utilizes polystyrene immunosticks as the solid substrate, chicken antitoxin (IgY) as the coating antibody, rabbit antitoxin as the primary antibody, and peroxidase-labeled goat-anti-rabbit as the secondary antibody. To evaluate the immunostick ELISA as a diagnostic test for avian botulism, known concentrations of toxin were added to heparinized blood collected from healthy birds and tested by both the ELISA and mouse bioassay. Also, blood samples from 236 bird carcasses submitted to the National Wildlife Health Center (NWHC) for cause of death determinations were tested by both procedures. Using ≤ 0.5 ml as the test volume for both procedures, the ELISA was less sensitive, detecting 0.25 ng/ml of toxin compared to 0.12 ng/ml for the mouse bioassay. Using the same volume of test sample for diagnostic submissions (≤ 0.5 ml), the ELISA was positive for 60% of the 149 clinically-diagnosed cases of botulism, whereas the mouse bioassay was positive for 79%. However, we demonstrated that with larger sample volumes (≥ 1.0 ml), the sensitivity of the ELISA may be equivalent or better than the mouse test due to the concentrating effect of the ELISA procedure. These preliminary results suggest that when adequate sample volumes are available, the immunostick ELISA can replace the mouse test for the diagnosis of botulism in wild birds.

Journal of Wildlife Diseases↗
USGS2002

Evaluation of longitudinal dispersivity estimates from forced-gradient tracer tests in heterogeneous aquifers

Converging radial-flow and two-well tracer tests are simulated in two-dimensional aquifers to investigate the effects of heterogeneity and forced-gradient test configuration on longitudinal dispersivity (??L) estimates, and to compare ??L estimates from forced-gradient tests with ??L values that characterize solute spreading under natural-gradient flow. Results indicate that in both mildly and highly heterogeneous aquifers, ??L estimates from two-well tests are generally larger than those from radial-flow tests. In mildly heterogeneous aquifers, ??L estimates from two-well tests with relatively large tracer transport distances are similar to ??L values from natural-gradient simulations. In highly heterogeneous aquifers, ??L estimates from two-well tests at all tracer transport distances are typically smaller than ??L values from natural-gradient simulations.

IAHS-AISH Publication↗
USGS2020

Design and operations of the Hydrate 01 Stratigraphic test well, Alaska North Slope

The National Energy Technology Laboratory, the Japan Oil, Gas and Metals National Corporation, and the U.S. Geological Survey are leading an effort to conduct an extended gas hydrate production test in northern Alaska. The proposed production test required the drilling of an initial stratigraphic test well (STW) to confirm the geologic conditions of the proposed test site. This well was completed in December 2018 in cooperation with the Prudhoe Bay Unit Interest Owners. With the success of the STW, the project leadership group is developing plans to drill a geologic data well and a production test well. Drilling plans for the STW were advanced in late 2018. The Prudhoe Bay Unit Hydrate-01 well was spudded on 10-December-2018. Downhole data acquisition was completed on 25-December-2018 and the rig was released on 01-January-2019. The STW was drilled in two sections. The surface hole was drilled to a depth of 2248 ft (MD, measured depth) and cased, and the “production hole section” was drilled to a depth of 3558 ft (MD) and also cased. A thermally chilled mineral-oilbased mud was used to maintain drillhole stability and quality of the borehole acquired data. The primary borehole data were acquired using a suite of Schlumberger logging-while-drilling tools. To gather grain size and other data needed to inform the design of the production test well, sidewall pressure cores were collected using Halliburton’s CoreVault tool. In addition to confirming the geologic conditions at the test site, the Hydrate-01 well was designed to serve as a monitoring well during future field operations. Therefore, two sets of fiber optic cables, each including bundled Distributed Acoustic Sensors (DAS) and Distributed Temperature Sensors (DTS), were clamped to the outside of the well casing and cemented in place. In March 2019, the project team worked with SAExploration to acquire 3D DAS Vertical Seismic Profiling (VSP) data in the Hydrate-01 well, which was the largest 3D DAS-VSP ever conducted. Additionally, since the December 2018 completion of the STW, several borehole temperature surveys have been acquired with the DTS deployed in the Hydrate-01 well.

Alaska↗
USGS2016

A goodness-of-fit test for occupancy models with correlated within-season revisits

Occupancy modeling is important for exploring species distribution patterns and for conservation monitoring. Within this framework, explicit attention is given to species detection probabilities estimated from replicate surveys to sample units. A central assumption is that replicate surveys are independent Bernoulli trials, but this assumption becomes untenable when ecologists serially deploy remote cameras and acoustic recording devices over days and weeks to survey rare and elusive animals. Proposed solutions involve modifying the detection-level component of the model (e.g., first-order Markov covariate). Evaluating whether a model sufficiently accounts for correlation is imperative, but clear guidance for practitioners is lacking. Currently, an omnibus goodnessof- fit test using a chi-square discrepancy measure on unique detection histories is available for occupancy models (MacKenzie and Bailey, Journal of Agricultural, Biological, and Environmental Statistics, 9, 2004, 300; hereafter, MacKenzie– Bailey test). We propose a join count summary measure adapted from spatial statistics to directly assess correlation after fitting a model. We motivate our work with a dataset of multinight bat call recordings from a pilot study for the North American Bat Monitoring Program. We found in simulations that our join count test was more reliable than the MacKenzie–Bailey test for detecting inadequacy of a model that assumed independence, particularly when serial correlation was low to moderate. A model that included a Markov-structured detection-level covariate produced unbiased occupancy estimates except in the presence of strong serial correlation and a revisit design consisting only of temporal replicates. When applied to two common bat species, our approach illustrates that sophisticated models do not guarantee adequate fit to real data, underscoring the importance of model assessment. Our join count test provides a widely applicable goodness-of-fit test and specifically evaluates occupancy model lack of fit related to correlation among detections within a sample unit. Our diagnostic tool is available for practitioners that serially deploy survey equipment as a way to achieve cost savings.

Ecology and Evolution↗