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At least 955 records · Page 53Linked to original sources

USGS1982

Mineral resource potential map of the Ramseys Draft Addition, Augusta and Highland counties, Virginia

Under the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and the U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. The act directs that the results of such surveys are to be made available to the public and be submitted to the President and the Congress. This report presents the results of a mineral survey of the Ramseys Draft Addition, which is a roadless area adjoining Ramseys Draft Wilderness Study Area in the George Washington National Forest, Augusta and Highland Counties, Virginia. The area was classified as a further planning area during the Second Roadless Area Review and Evaluation (RARE II) by the U.S. Forest Service, January 1979.

Virginia↗

USGS1980

Reassessment of the effects of construction dewatering on ground-water levels in the Cowles Unit, Indiana Dunes National Lakeshore, Indiana : Supplement to Geological Survey Water Resources Investigations 78-138

A revised dewatering plan for the construction of a nuclear power plant at the Northern Indiana Public Service Company 's (NIPSCO) Bailly Generating Station and evidence that suggests that a change in the characteristics of the confining unit 2 in and near Cowles Bog National Landmark may exist have resulted in a reassessment of the effects of construction dewatering on ground-water levels in the Indiana Dunes National Lakeshore. Model results indicate that the revision in the dewatering plan produces water-level declines that do not differ significantly from those described previously. However, when the change in the confining unit beneath Cowles Bog is considered, simulations of the simultaneous decline of a seepage mound after sealing of the fly-ash-ponds and the second phase of construction dewatering indicate that the simulated water-level declines in the aquifer unit 1 at Cowles Bog may be below the water levels tolerated by the National Park Service after 18 months. The water levels may even decline below the tolerable levels in spite of NIPSCO 's proposed plan of artificially recharging the aquifer unit 1 near the excavation site at 400 gal/min. The magnitude of the simulated water-level declines in unit 1 within the Lakeshore, caused by pumping from the excavation, depends on the relation in time between the second phase of dewatering and the decline of the seepage mound after sealing of the fly-ash-ponds, but not on the duration of dewatering beyond 18 months. (USGS)

Indiana↗

USGS2012

Survey of hydrologic models and hydrologic data needs for tracking flow in the Rio Grande, north-central New Mexico, 2010

The six Middle Rio Grande Pueblos have prior and paramount rights to deliveries of water from the Rio Grande for their use. When the pueblos or the Bureau of Indian Affairs Designated Engineer identifies a need for additional flow on the Rio Grande, the Designated Engineer is tasked with deciding the timing and amount of releases of prior and paramount water from storage at El Vado Reservoir to meet the needs of the pueblos. Over the last three decades, numerous models have been developed by Federal, State, and local agencies in New Mexico to simulate, understand, and (or) manage flows in the Middle Rio Grande upstream from Elephant Butte Reservoir. In 2008, the Coalition of Six Middle Rio Grande Basin Pueblos entered into a cooperative agreement with the U.S. Geological Survey to conduct a comprehensive survey of these hydrologic models and their capacity to quantify and track various components of flow. The survey of hydrologic models provided in this report will help water-resource managers at the pueblos, as well as the Designated Engineer, make informed water-resource-management decisions that affect the prior and paramount water use. Analysis of 4 publicly available surface-water models and 13 publicly available groundwater models shows that, although elements from many models can be helpful in tracking flow in the Rio Grande, numerous data gaps and modeling needs indicate that accurate, consistent, and timely tracking of flow on the Rio Grande could be improved. Deficient or poorly constrained hydrologic variables are sources of uncertainty in hydrologic models that can be reduced with the acquisition of more refined data. Data gaps need to be filled to allow hydrologic models to be run on a real-time basis and thus ensure predictable water deliveries to meet needs for irrigation, domestic, stock, and other water uses. Timeliness of flow-data reporting is necessary to facilitate real-time model simulation, but even daily data are sometimes difficult to obtain because the data come from multiple sources. Each surface-water model produces results that could be helpful in quantifying the flow of the Rio Grande, specifically by helping to track water as it moves down the channel of the Rio Grande and by improving the understanding of river hydraulics for the specified reaches. The ability of each surface-water model to track flow on the Rio Grande varies according to the purpose for which each model was designed. The purpose of Upper Rio Grande Water Operations Model (URGWOM) - to simulate water storage and delivery operations in the Rio Grande - is more applicable to tracking flow on the Rio Grande than are any of the other surface-water models surveyed. Specifically, the strengths of URGWOM in relation to modeling flow are the details and attention given to the accounting of Rio Grande flow and San Juan-Chama flow at a daily time step. The most significant difficulty in using any of the surveyed surface-water models for the purpose of predicting the need for requested water releases is that none of the surface-water models surveyed consider water accounting on a real-time basis. Groundwater models that provide detailed simulations of shallow groundwater flow in the vicinity of the Rio Grande can provide large-scale estimates of flow between the Rio Grande and shallow aquifers, which can be an important component of the Rio Grande water budget as a whole. The groundwater models surveyed for this report cannot, however, be expected to provide simulations of flow at time scales of less than the simulated time step (1 month to 1 year in most cases). Of those of the currently used groundwater models, the purpose of model 13 - to simulate the shallow riparian groundwater environment - is the most appropriate for examining local-scale surface-water/groundwater interactions. The basin-scale models, however, are also important in understanding the large-scale water balances between the aquifers and the surface water. In the case of the Upper and Middle Rio Grande Valley, models 6, 10, and 12 are the most accurate and current groundwater models available.

Colorado;New Mexico↗

USGS2023

Evaluating oil and gas industry two-dimensional multichannel seismic data for use in near-surface assessment of geologic framework and potential marine minerals resources

Marine seismic reflection data acquired across the Gulf of Mexico during oil and gas exploration are available to the public through an online database archive. The data are archived as two-dimensional multichannel seismic data in two digital formats. The formats include image files in portable document format (PDF), and binary files in industry standard Society for Exploration Geophysicists revision Y (SEG-Y) format. Also included in the database are navigation files and acquisition information associated with the collection of the data. This study examines the data acquired within two geographic areas in the northern Gulf of Mexico. Although the seismic reflection data are acquired for oil and gas exploration many kilometers below the seafloor, this study focuses on the feasibility of using the data for near-surface geologic and seafloor morphologic studies (<100 meters below the seafloor). The report outlines the methodologies used to recover and process the data, including computer processing steps to convert the PDF imagery into SEG-Y format. The report includes two-dimensional profiles of the data to demonstrate the efficacy of the data in near-surface geologic studies. The study found that, for the two areas of interest, the seafloor reflectors in most of the available data are not resolvable. Although the data are readily available and computer processing can adequately image the uppermost reflectors of the seismic profiles, the resolution of the data in most cases are not suitable for near-surface geologic evaluations.

Alabama, Florida, Louisiana, Mississippi, Texas↗

USGS1961

Records and water-level measurements of selected wells and chemical analysis of ground water, East Shore area, Davis, Weber, and Box Elder Counties

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 1935-61 by the U.S. Geological Survey in cooperation with the Utah State Engineer as a part of the investigation of the ground-water resources of the East Shore area in Davis, Weber, and southern Box Elder Counties, Utah. During the period 1952-61 additional records were collected by the U.S. Bureau of Reclamation. The interpretive material will be published cooperatively by the U.S. Geological Survey and the Utah State Engineer as a report entitled "Groundwater conditions in the East Shore area, Utah, 1953-61," by Ralph E. Smith. 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 on the tables and figures. From table 1 he can note (1) the depth and diameter of wells in the vicinity and the yield of some of those wells, and (2) the depth to water or the feet of water pressure in wells in the vicinity; from table 2 and figure 2 he may note the historic fluctuations and trends of water levels in the vicinity; and from tables 3 and l he may note the chemical quality of the water from wells in the vicinity and the use made of this water. If the reader decides from his examination that conditions are favorable, he may 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.

Utah↗

USGS1962

Records of selected wells and springs, selected drillers' logs of wells, and chemical analyses of ground and surface waters, northern Utah Valley, Utah County, Utah

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 1956-59 by the U.S. Geological Survey in cooperation with the Utah State Engineer as a part of the investigation of the ground-water resources of northern Utah Walley in Utah County, Utah. Some earlier data and other information in the tables are from published reports on the ground-water resources of northern Utah Walley. The interpretive material will be published cooperatively by the U.S. Geological Survey and the Utah State Engineer in a companion report by Seymour Subitzky. 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 on the tables. From tables 1, 2, and h he can note the type of material that yields water to wells in the vicinity; from table 2 he can note (1) the depth and diameter of wells in the vicinity and the yield of some of those wells, and (2) the depth to water or the feet of water pressure in the vicinity; from table 3 and plate 1 he may note the location of springs and the conditions related to the occurrence of these springs; and from tables 5 and 6 he may note the chemical quality of the water from wells and from some surface sources, and the uses of these waters. If the reader decides from his examination that conditions are favorable, he may 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.

Utah↗

USGS1963

Ground-water data: Beaver, Escalante, Cedar City, and Parowan Valleys; parts of Washington, Iron, Beaver, and Millard Counties, Utah

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 1935-62 by the U.S. Geological Survey in cooperation with the Utah State Engineer as part of the investigation of ground-water conditions in the Beaver, Escalante, Cedar City, and Parowan Walleys. This report will include records collected subsequent to data published in earlier reports listed in the bibliography. The interpretive material will be published in a companion report by George W. Sandberg. 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 figure 2. From table 1 he can note such things as diameter, depth, water level, yield, use of water, and depth to aquifers in wells in the vicinity, and from the well logs in table 3 he can note the type of material that yields water to the wells. Table 2 gives several years record of yields and pumping levels of irrigation wells, and in table 4 are the chemical analyses of water from wells and springs. Figure 2 shows the historic fluctuations and trends of water levels in the four valleys. If the reader decides from his examination that conditions are favorable, he can place an application to drill a well with the State Engineer. During the past several years, however, the State Engineer has rejected new applications to appropriate water in major portions of Beaver Valley, Milford and Beryl-Enterprise districts in Escalante Valley, and Cedar City Valley. Anyone seeking to initiate a new ground-water right in any of these areas should obtain information from the State Engineer's Office in either Salt Lake City or Cedar City to determine the likelihood of approval of the required application. 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.

Utah↗

USGS1964

Selected hydrologic data, upper Sevier River basin, Utah

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 1961-63 by the U.S. Geological Survey in cooperation with the Utah State Engineer as a part of the investigation of ground-water conditions in the upper Sevier River basin, in parts of Garfield, Iron, Kane, Piute, and Sevier Counties, Utah. The interpretive material will be published in a companion report by Carl H. Carpenter, Gerald B. Robinson, Jr., and Louis J. Bjorklund. 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 and springs as shown in the tables. From table 1 he can find information on wells, including depth, diameter, water level, yield, drawdown, use of water, temperature of water, and depth of perforations. Table 2 gives information on springs such as yield, use of water, temperature, and improvements. From tables 1 and 2 he can note the type of material that yields water in the vicinity. Table 3 shows the historic fluctuations and trends of water levels. Table 4 shows the type of material penetrated by wells. From table 5 he can note the chemical quality of water from wells and springs, and from table 6, the chemical quality of surface water. 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.

Utah↗

USGS2007

Managing the rippling stream: decisionmaking in natural resource administration

This article addresses the conflict which exists within the water resources decisionmaking arena over the allocation of water for instream uses. The discussion reviews the literature on public administration regarding decisionmaking, and is based on research performed by the authors which synthesizes a model of decisionmaking. This model can be used as both a description of agency behavior, and as the basis for developing a prescription for strategy formulation.

Journal of the American Water Resources Associatio↗

USGS2013

Metrically preserving the USGS aerial film archive

Since 1972, the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota, has provided fi lm-based products to the public. EROS is home to an archive of 12 million frames of analog photography ranging from 1937 to the present. The archive contains collections from both aerial and satellite platforms including programs such as the National High Altitude Program (NHAP), National Aerial Photography Program (NAPP), U.S. Antarctic Resource Center (USARC), Declass 1(CORONA, ARGON, and LANYARD), Declass 2 (KH-7 and KH-9), and Landsat (1972 – 1992, Landsat 1–5).

Photogrammetric Engineering and Remote Sensing↗

USGS2021

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2018 annual report

The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years) science-based program that assesses and enhances the quality and quantity of wildlife habitats in the southwest Wyoming region while facilitating responsible development. The USGS WLCI Science Team completes scientific research and develops tools that inform and support WLCI partner planning, decision making, and on-the-ground management actions. In fiscal year 2018, the USGS initiated 3 new projects and continued efforts on 21 ongoing science and web-development projects. The first new project was initiated to support Secretarial Order 3362 which calls on the USGS to assist Western States in mapping big-game migration corridors and developing new mapping tools. During 2018, the USGS hosted a workshop in Laramie, Wyoming, which included more than 70 State and Federal wildlife experts from Colorado, New Mexico, Texas, and Wyoming. Most of the mapping and migration tool curricula used in the workshop were derived from prior WLCI studies and mapping efforts of big-game migration movement in habitats undergoing large-scale energy development. The second new project was in response for WLCI partners to better understand sedimentation and hydrogeomorphic processes in a cold-desert headwater and the third new project was designed to improve our approach for people to access, manage, and analyze WLCI data and WLCI resource information. The USGS published 18 products (including peer-reviewed journal articles, USGS series publications, and data releases) and provided more than a dozen professional oral and poster presentations at scientific meetings and numerous informal presentations to WLCI partners at meetings and workshops. This report summarizes the objectives and status of each project and highlights the USGS 2018 accomplishments and products.

Wyoming↗

USGS2018

Science support for evaluating natural recovery of polychlorinated biphenyl concentrations in fish from Crab Orchard Lake, Crab Orchard National Wildlife Refuge, Illinois

Introduction Crab Orchard Lake in southern Illinois is one of the largest and most popular recreational lakes in the state. Construction of the nearly 7,000-acre reservoir in the late 1930s created employment opportunities through the Works Progress Administration, and the lake itself was intended to supply water, control flooding, and provide recreational opportunities for local communities (Stall, 1954). In 1942, the Department of War appropriated or purchased more than 20,000 acres of land around Crab Orchard Lake and constructed the Illinois Ordnance Plant, which manufactured bombs and anti-tank mines during World War II. After the war, an Act of Congress transferred the property to the U.S. Department of the Interior. Crab Orchard National Wildlife Refuge was established on August 5, 1947, for the joint purposes of wildlife conservation, agriculture, recreation, and industry. Production of explosives continued, but new industries also moved onsite. More than 200 tenants have held leases with Crab Orchard National Wildlife Refuge and have operated a variety of manufacturing plants (electrical components, plated metal parts, ink, machined parts, painted products, and boats) on-site. Soils, water, and sediments in several areas of the refuge were contaminated with hazardous substances from handling and disposal methods that are no longer acceptable environmental practice (for example, direct discharge to surface water, use of unlined landfills). Polychlorinated biphenyl (PCB) contamination at the refuge was identified in the 1970s, and a PCB-based fish-consumption advisory has been in effect since 1988 for Crab Orchard Lake. The present advisory covers common carp ( Cyprinus carpio ) and channel catfish ( Ictalurus punctatus ); see Illinois Department of Public Health (2017). Some of the most contaminated areas of the refuge were actively remediated, and natural ecosystem recovery processes are expected to further reduce residual PCB concentrations in the lake. The U.S. Fish and Wildlife Service sought technical support to understand environmental drivers of current (2017) PCB residues in fish tissue and patterns in PCB residues through time to inform the fish-consumption advisory for Crab Orchard Lake. This project is planned in two phases (Tasks 1 and 2); the first phase is included in this report. Task 1, reported here, includes a review of existing literature and a brief overview focused on environmental and biochemical/physiological processes that drive PCB residues in fish tissue. This review specifically targets processes that are relevant for freshwater lacustrine environments such as those at Crab Orchard Lake. In addition to discussions of environmental fate, metabolism, and accumulation of PCBs, this review includes a brief scientifically based explanation of approaches used to establish fish-consumption advisories. A planned second task (Task 2) will include a compilation and summary of existing data on PCB residues in fish tissue samples from Crab Orchard Lake. This summary will also place Crab Orchard Lake data in a broader geographic context through a comparison with fish data from other Midwestern lakes. When Task 1 and Task 2 are complete, resource managers will have (a) a synthesis of existing literature that characterizes the processes influencing the fate of residual PCBs remaining in systems such as Crab Orchard Lake, (b) a summary of natural PCB attenuation processes for use in risk communication with the public, and (c) a summary of existing data on PCBs in fish tissues from Crab Orchard Lake, including exploratory plots of tissue residues through time. Overall, this project will provide data to help resource managers better understand the ecological and public health consequences of residual PCBs in Crab Orchard Lake.

Illinois↗

USGS1995

1995 annual report on Alaska's mineral resources

Section 1011 of the Alaska National Interest Lands Conservation Act (ANILCA) of 1980, as amended, requires that "On or before October 1, 1982, and annually thereafter, the President shall transmit to the Congress all pertinent public information relating to minerals in Alaska gathered by the United States Geological Surveys, United States Bureau of Mines, and any other Federal agency." This report has been prepared in response to that requirement. This circular is the fourteenth in the series of annual mineral reports mandated by the ANILCA. The report provides information about current Alaskan mineral projects and events during 1994; the emphasis is on Federal activity. The report addresses both onshore and offshore areas of Alaska. The U.S. Geological Survey (USGS), U.S. Bureau of Mines (USBM), and Minerals Management Service (MMS) are the principal Federal agencies that publish information about energy and mineral resources in Alaska. Their reports and data form the basis for decisions by other Federal agencies regarding land use, access, environmental impacts, and mining claim evaluation. The time required for sample analysis, data synthesis, and publication is lengthy; as a result, scientific reports are generally issued a year or more after initial sample and data collection. Other sources of information for this report include additional Federal and State publications, trade and professional journals, presentations at public meetings and hearings, and press releases. Information is provided for two broad categories of minerals: energy resources and nonfuel-mineral resources.

Circular↗

USGS2015

Geochemical conditions and the occurrence of selected trace elements in groundwater basins used for public drinking-water supply, Desert and Basin and Range hydrogeologic provinces, 2006-11: California GAMA Priority Basin Project

The geochemical conditions, occurrence of selected trace elements, and processes controlling the occurrence of selected trace elements in groundwater were investigated in groundwater basins of the Desert and Basin and Range (DBR) hydrogeologic provinces in southeastern California as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP is designed to provide an assessment of the quality of untreated (raw) groundwater in the aquifer systems that are used for public drinking-water supply. The GAMA PBP is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The DBR hydrogeologic provinces consist of 141 defined groundwater basins separated by mountain ranges, faults, and other features. This report presents analyses of data collected from nine study areas within the DBR hydrogeologic provinces: Antelope Valley, Borrego Valley, the Central Desert area, Coachella Valley, Colorado River, Indian Wells Valley, Low-Use Basins of the Mojave and Sonoran Deserts, the Mojave, and Owens Valley. Collectively, these nine study areas are referred to as the DBR study unit. The study unit covers approximately 7,000 square miles and includes the 63 groundwater basins in the DBR hydrogeologic provinces in which groundwater is used for public drinking-water supply. The vast majority of the 223 wells sampled for this study were long-screened production wells used primarily for public supply. Uncorrected carbon-14 ( 14 C) groundwater ages for samples collected in the DBR study unit ranged from less than (<) 100 to 33,700 years before present (BP). Sixty-six percent of sample ages were greater than (>) 100 years BP, and 40 percent were >3,800 years BP. Samples collected from wells located adjacent to mountain-front recharge areas or major surface-water features generally had younger groundwater ages than did samples collected from wells located away from mountain fronts or towards the distal ends of basin groundwater flow paths. Most groundwater sampled in the DBR study unit had alkaline pH: 89 percent of sample pH values ranged from 7.1 to 9.8, with 37 percent greater than or equal to (≥) 7.9. Groundwater age was significantly correlated (positively) with pH, likely because silicate weathering is a primary control on groundwater pH and is a slow process. The oxidation-reduction (redox) condition of the groundwater sampled in the DBR study unit was predominantly oxic (71 percent), except in the Colorado River study area where organic-rich fluvial aquifers provide the electron donors necessary to support iron-reducing (anoxic-Fe) redox processes. The cation type of 78 percent of the samples was either sodium- or mixed-type, and the anion type of 83 percent of the samples was either bicarbonate- or mixed-type. Sodium-type groundwaters generally were older and more alkaline than calcium-type groundwaters, consistent with the change in water chemistry expected from cation exchange between groundwater and aquifer sediments over long periods of time. Because of the correlation with young groundwater, calcium-type groundwater was predominantly from wells located adjacent to mountain-front recharge areas. Arsenic (As), boron (B), fluoride (F), molybdenum (Mo), strontium (Sr), uranium (U), and vanadium (V) were selected for assessment in this study because they occurred at concentrations greater than California Department of Public Health or U.S. Environmental Protection Agency regulatory or non-regulatory drinking-water-quality benchmarks in more than 2 percent of the 223 samples collected in the DBR study unit. As and F were detected most commonly (18 and 13 percent, respectively) at concentrations above associated water-quality benchmarks and Sr and V least frequently (both at 3 percent). Given that 14 C groundwater ages are predominantly >100 years BP, land use in the study unit is primarily undeveloped, and chemicals derived from anthropogenic sources, such as volatile organic compounds, were infrequently detected, high concentrations of these trace elements in groundwater were most likely the result of natural factors and not anthropogenic factors. As, F, Mo, and V concentrations showed significant positive correlations to groundwater age and to pH. This relation is partly due to the sources of trace elements likely being the weathering of primary minerals, such as silicate minerals, which is a slow process that takes place over hundreds to thousands of years. This relation also reflects the positive correlation between groundwater age and pH. Geochemical modeling predicted that the dominant species of As, Mo, and V in solution were oxyanions (HAsO 4 2– , MoO 4 2– , and H 2 VO 4– ), which are likely to be mobile in alkaline groundwater because mineral surfaces composing aquifer matrices have a predominantly negative surface charge under alkaline conditions. F also exists predominantly as a negatively charged ion (F – ). At pH values >7.5, saturation indices generated by the geochemical modeling program PHREEQC indicated that F solubility may be somewhat limited by the precipitation of the mineral fluorapatite [Ca 5 (PO 4 ) 3 F]. Speciation modeling of As in anoxic-Fe groundwater (iron-reducing conditions) showed that samples were supersaturated with orpiment (As 2 S 3 ), indicating that mineral precipitation may be responsible for low As concentrations observed in reducing groundwater. In contrast, U concentrations showed significant negative correlations to groundwater age and to pH. Higher U concentrations generally occurred in samples for which geochemical modeling indicated that the uncharged ternary complex Ca 2 UO 2 (CO 3 ) 3 was the dominant aqueous U species. This uncharged complex is not attracted to the charged surfaces of minerals and thus increases U solubility. Formation of Ca 2 UO 2 (CO 3 ) 3 was greater in younger groundwaters because calcium and uranium concentrations generally were lower in older groundwaters, likely due to cation-exchange processes and precipitation of the mineral calcite as groundwater pH increased. Co-precipitation of U with the calcite (CaCO 3 ) may remove U from the aqueous phase. Saturation indices indicated that the anoxic-Fe groundwaters from the Colorado River study area were supersaturated with the mineral uraninite (UO 2 ), suggesting that UO 2 precipitation may be responsible for the low concentrations of U observed in these samples. Concentrations of strontium, which exists primarily in a cationic form (Sr 2+ ), were not significantly correlated with either groundwater age or pH. Strontium concentrations showed a strong positive correlation with total dissolved solids (TDS). Dissolved constituents, such as Sr, that interact with mineral surfaces through outer-sphere complexation become increasingly soluble with increasing TDS concentrations of groundwater. Boron concentrations also showed a significant positive correlation with TDS, indicating the B may interact to a large degree with mineral surfaces through outer-sphere complexation.

California↗

USGS2007

Shuttle Radar Topography Mission - New Products in 2005

In February 2000, the Shuttle Radar Topography Mission (SRTM) successfully collected Interferometric C-Band Synthetic Aperture Radar data over 80 percent of the Earth's land surface, for most of the area between 60?N and 56?S latitude. NASA and the National Geospatial-Intelligence Agency (NGA), formerly known as the National Imagery and Mapping Agency (NIMA), co-sponsored the mission. NASA's Jet Propulsion Laboratory (JPL) performed preliminary processing of SRTM data and forwarded partially finished data directly to NGA for finishing by NGA contractors and subsequent monthly deliveries to the NGA Digital Products Data Warehouse (DPDW). All data products delivered by the contractors conform to NGA SRTM Data Products and NGA Digital Terrain Elevation Data? (DTED?) specifications. The DPDW ingests the SRTM data products, checks them for formatting errors, loads the public SRTM DTED? into the NGA data distribution system, and ships them to the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS). In addition to NGA's SRTM DTED? format, USGS EROS has reformatted the data into a non-proprietary, generic raster binary SRTM format that is readable by most remote sensing software packages. The SRTM format is also publicly available from USGS EROS.

Fact Sheet↗

USGS1993

Description of water-resource-related data compiled for Harvey County, south-central Kansas

Site, construction, geologic, water-level, water- quality, water-withdrawal, and well-survey data for sites in Harvey County were compiled in cooper- ation with the Harvey County Health Department as part of the Kansas Department of Health and Environment's Local Environmental Protection Program (LEPP). These data were entered into a relational data-base management system (RDBMS) to facilitate the analysis required to meet the LEPP goals of developing plans for nonpoint-source management and for public-water-supply protection. The data in the RDBMS are organized into digital data sets. The data sets contain the water- resource-related data compiled by the U.S. Geological Survey for 668 wells; by the Kansas Department of Health and Environment for 1,636 wells, 6 public-water-supply systems, 6 streams, and 2 surface-water impoundments; by the Kansas State Board of Agriculture for 423 wells and 26 streams or impoundments; by well-drilling con- tractors and the Kansas Geological Survey for 126 wells; and by Harvey County for 89 wells. In addition, data on 761 wells and 133 sites without wells resulting from a survey of rural landowners and residents by Harvey County as a part of the LEPP are contained in another data set. The data in these 7 data sets are available from the Harvey County Health Department in Newton, Kansas. (USGS)

Open-File Report↗

USGS2016

Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory. The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors. The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N -nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non-regulatory benchmarks for drinking-water quality. For inorganic, organic, and special-interest constituents, a relative-concentration greater than 1.0 indicates a concentration greater than the benchmark and is classified as high. Inorganic constituents are classified as moderate if relative-concentrations are greater than 0.5 and less than or equal to 1.0 and are classified as low if relative-concentrations are less than or equal to 0.5. For organic and special-interest constituents, the boundary between moderate and low relative-concentrations was set at 0.1. Aquifer-scale proportion was used as the primary metric for evaluating regional-scale groundwater quality. High aquifer-scale proportion is defined as the areal percentage of the primary aquifer system with a relative-concentration greater than 1.0 for a particular constituent or class of constituents. Moderate and low aquifer-scale proportions were defined as the areal percentage of the primary aquifer system that had moderate and low relative-concentrations, respectively. Two statistical approaches—grid based and spatially weighted—were used to calculate aquifer-scale proportions for individual constituents and constituent classes. Grid-based and spatially weighted estimates were comparable in this the study (within 90-percent confidence intervals). Grid-based results were selected for use in the status assessment unless, as was observed in a few cases, a grid-based result was zero and the spatially weighted result was not zero, in which case, the spatially weighted result was used. Inorganic constituents that have human-health benchmarks were present at high relative-concentrations in 5.3 percent of the primary aquifer system and at moderate concentrations in 32 percent. High aquifer-scale proportions of inorganic constituents primarily were a result of high aquifer-scale proportions of boron (5.3 percent) and fluoride (5.3 percent). Inorganic constituents that have aesthetic-based benchmarks, referred to as secondary maximum contaminant levels, were present at high relative-concentrations in 58 percent of the primary aquifer system and at moderate concentrations in 37 percent. Iron, manganese, sulfate, and total dissolved solids were the inorganic constituents with secondary maximum contaminant levels present at high relative-concentrations. In contrast, organic and special-interest constituents that have health-based benchmarks were not detected at high relative-concentrations in the primary aquifer system. Of the 218 organic constituents analyzed, 10 were detected—9 that had human-health benchmarks. Organic constituents were present at moderate relative-concentrations in 11 percent of the primary aquifer system. The moderate aquifer-scale proportions were a result of moderate relative-concentrations of the volatile organic compounds methyl tert- butyl ether (MTBE, 11 percent) and 1,2-dichloroethane (5.6 percent). The volatile organic compounds 1,1,1-trichloroethane, 1,1-dichloroethane, bromodichloromethane, chloroform, MTBE, and perchloroethene (PCE); the pesticide simazine; and the special-interest constituent perchlorate were detected at more than 10 percent of the sites in the Santa Barbara study unit. Perchlorate was present at moderate relative-concentrations in 50 percent of the primary aquifer system. Pharmaceutical compounds and NDMA were not detected in the Santa Barbara study unit.

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USGS2008

Base of principal aquifer for the Elkhorn-Loup model area, North-Central Nebraska

In Nebraska, the water managers in the Natural Resources Districts and the Nebraska Department of Natural Resources are concerned with the effect of ground-water withdrawal on the availability of surface water and the long-term effects of ground-water withdrawal on ground- and surface-water resources. In north-central Nebraska, in the Elkhorn and Loup River Basins, ground water is used for irrigation, domestic supply, and public supply; surface water is used in this area for irrigation, recreation, and hydropower production. In recognition of these sometimes competing ground- and surface-water uses in the Elkhorn and Loup River Basins, the U.S. Geological Survey, the Lewis and Clark Natural Resources District, the Lower Elkhorn Natural Resources District, the Lower Loup Natural Resources District, the Lower Niobrara Natural Resources District, the Lower Platte North Natural Resources District, the Middle Niobrara Natural Resources District, the Upper Elkhorn Natural Resources District, and the Upper Loup Natural Resources District agreed to cooperatively study water resources in the Elkhorn and Loup River Basins. The goals of the overall study were to construct and calibrate a regional ground-water flow model of the area and to use that flow model as a tool to assess current and future effects of ground-water irrigation on stream base flow and to help develop long-term water-resource management strategies for this area, hereafter referred to as the Elkhorn-Loup model area. The Elkhorn-Loup model area covers approximately 30,800 square miles, and extends from the Niobrara River in the north to the Platte River in the south. The western boundary of the Elkhorn-Loup model area coincides with the western boundary of the Middle Niobrara, Twin Platte, and Upper Loup Natural Resources Districts; the eastern boundary coincides with the approximate location of the western extent of glacial till in eastern Nebraska. The principal aquifer in most of the Elkhorn-Loup model area is the High Plains aquifer; the principal aquifer in the remaining part of the Elkhorn-Loup model area is an unnamed alluvial aquifer. The upper surface of the geologic units that directly underlie the aquifer is called the 'base of aquifer' in this report. The geologic unit that forms the base of aquifer in the Elkhorn-Loup model area varies by location. The Tertiary-age Brule Formation generally is the base of aquifer in the west; the Cretaceous-age Pierre Shale generally is the base of aquifer in the east. The purpose of this report is to update the altitude and configuration of the base of the principal aquifer in the Elkhorn-Loup model area and a 2-mile buffer area around the Elkhorn-Loup model area, using base-of-aquifer data from test holes, registered water wells, and oil and gas wells within the Elkhorn-Loup model area and a 20-mile buffer area around the Elkhorn-Loup model area that have become available since the publication of earlier maps of the base of aquifer for this area. The base-of-aquifer map is important for the Elkhorn-Loup ground-water flow model because it defines the model's lower boundary. The accuracy of the Elkhorn-Loup ground-water flow model and the accuracy of the model's predictions about the effects of ground-water irrigation on stream base flow are directly related to the accuracy of the model's lower boundary.

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