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USGS2004

Guidelines for preparation of state water-use estimates for 2000

This report describes the water-use categories and data elements required for the 2000 national water-use compilation conducted by the U.S. Geological Survey (USGS) as part of its National Water Use Information Program. It identifies sources of water-use information, guidelines for estimating water use, and required documentation for preparation of the national compilation by State for the United States, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands. The data are published in USGS Circular 1268, Estimated Use of Water in the United States in 2000. USGS has published circulars on estimated use of water in the United States at 5-year intervals since 1950. As part of this USGS program to document water use on a national scale for the year 2000, all States prepare estimates of water withdrawals for public supply, industrial, irrigation, and thermoelectric power generation water uses at the county level. All States prepare estimates of domestifc use and population served by public supply at least at the State level. All States provide estimates of irrigated acres by irrigation system type (sprinkler, surface, or microirrigation) at the county level. County-level estimates of withdrawals for mining, livestock, and aquaculture uses are compiled by selected States that comprised the largest percentage of national use in 1995 for these categories, and are optional for other States. Ground-water withdrawals for public-supply, industrial, and irrigation use are aggregated by principal aquifer or aquifer system, as identified by the USGS Office of Ground Water. Some categories and data elements that were mandatory in previous compilations are optional for the 2000 compilation, in response to budget considerations at the State level. Optional categories are commercial, hydroelectric, and wastewater treatment. Estimation of deliveries from public supply to domestic, commercial, industrial, and thermoelectric uses, consumptive use for any category, and irrigation conveyance loss are optional data elements. Aggregation of data by the eight-digit hydrologic cataloging unit is optional. Water-use data compiled by the States are stored in the USGS Aggregated Water-Use Data System (AWUDS). This database is designed to store both mandatory and optional data elements. AWUDS contains several routines that can be used for quality assurance and quality control of the data, and also produces tables of water-use data compiled for 1985, 1990, 1995, and 2000. These water-use data are used by USGS, other agencies, organizations, academic institutions, and the public for research, water-management decisions, trend analysis, and forecasting.

Techniques and Methods↗
USGS1990

Evaluation of site-selection criteria, well design, monitoring techniques, and cost analysis for a ground-water supply in Piedmont crystalline rocks, North Carolina

A statistical analysis of data from wells drilled into the crystalline rocks of the Piedmont and Blue Ridge provinces of North Carolina verified and refined previously proposed criteria for the siting of wells to obtain greater than average yields. An opportunity to test the criteria was provided by the expansion of the town of Cary's municipal ground-water system. Three criteria were used: type of rock, thickness of saturated regolith based upon topography, and presence of fractures and joints based upon drainage lineations. A conceptual model of the local hydrogeologic system was developed to guide the selection of the most favorable well sites, and on the basis of the model, six type sites were determined. Eleven of 12 test wells that were located on the basis of type sites yielded from slightly above average to as much as six times the average yield to be expected from particular rock types as reported in the literature. Only one well drilled at a type site had a less than average yield. One well not located at any of the type sites produced little water. Long-term testing and monitoring after the wells were put into production showed that an 18-hour-on, 6-hour-off pumping cycle was much more effective in terms of total production, reduced head loss, and less drawdown than a 5-day-on and 2-day-off cycle. It was also observed that long-term yields by the production wells were about 75 percent of those predicted on the basis of 24-hour pumping tests and only about 60 percent of the driller's reported yields. Cost analysis showed that, by using criteria-selected well sites, a cost-effective well system can be developed that will provide water at an equivalent or lower cost than a surface-water supply. The analysis showed that the system would be cost effective if only one high-yield well were obtained out of every four drilled.

North Carolina↗
USGS2019

Estimating sand concentrations using ADCP‐based acoustic inversion in a large fluvial system characterized by bi‐modal suspended‐sediment distributions

Quantifying sediment flux within rivers is a challenge for many disciplines due, mainly, to difficulties inherent to traditional sediment sampling methods. These methods are operationally complex, high cost, and high risk. Additionally, the resulting data provide a low spatial and temporal resolution estimate of the total sediment flux, which has impeded advances in the understanding of the hydro‐geomorphic characteristics of rivers. Acoustic technologies have been recognized as a leading tool for increasing the resolution of sediment data by relating their echo intensity level measurements to suspended sediment. Further effort is required to robustly test and develop these techniques across a wide range of conditions found in natural river systems. This article aims to evaluate the application of acoustic inversion techniques using commercially available, down‐looking acoustic Doppler current profilers (ADCPs) in quantifying suspended sediment in a large sand bed river with varying bi‐modal particle size distributions, wash load and suspended‐sand ratios, and water stages. To achieve this objective, suspended sediment was physically sampled along the Paraná River, Argentina, under various hydro‐sedimentological regimes. Two ADCPs emitting different sound frequencies were used to simultaneously profile echo intensity level within the water column. Using the sonar equation, calibrations were determined between suspended‐sand concentrations and acoustic backscatter to solve the inverse problem. The study also analyzed the roles played by each term of the sonar equation, such as ADCP frequency, power supply, instrument constants, and particle size distributions typically found in sand bed rivers, on sediment attenuation and backscatter. Calibrations were successfully developed between corrected backscatter and suspended‐sand concentrations for all sites and ADCP frequencies, resulting in mean suspended‐sand concentration estimates within about 40% of the mean sampled concentrations. Noise values, calculated using the sonar equation and sediment sample characteristics, were fairly constant across evaluations, suggesting that they could be applied to other sand bed rivers.

Earth Surface Processes and Landforms↗
USGS2023

Comprehensive inventory of habitat assessment and evaluation datasets to support Deepwater Horizon mesophotic and deep benthic communities

This report is part of the NOAA Mesophotic and Deep Benthic Communities (MDBC) Series of publications that share the results of work conducted by the Deepwater Horizon MDBC restoration projects. The 2010 Deepwater Horizon oil spill was an unprecedented event. Approximately 3.2 million barrels of oil were released into the deep ocean over nearly three months. The plume of oil moved throughout the water column, formed surface slicks that cumulatively covered an area the size of Virginia, and washed oil onto at least 1,300 miles of shoreline habitats. More than 770 square miles (2,000 square kilometers) of deep benthic habitat surrounding the Deepwater Horizon wellhead and 4-square miles of the Pinnacles mesophotic reef complex, located at the edge of the continental shelf, were injured by the oil spill. Under the Oil Pollution Act, state and federal natural resource trustees conducted a Natural Resource Damage Assessment (NRDA). The Trustees assessed damages, quantifying the unprecedented injuries to natural resources and lost services. They also developed a programmatic restoration plan to restore injured resources and compensate the public for lost services. In April 2016, a settlement was finalized that included up to $8.8 billion in funding for the Deepwater Horizon Trustees to restore the natural resource injuries caused by the oil spill as described in their programmatic restoration plan, Final Programmatic Damage Assessment and Restoration Plan and Final Programmatic Environmental Impact Statement. The Deepwater Horizon Open Ocean Trustee Implementation Group is responsible for restoring natural resources and their services within the Open Ocean Restoration Area that were injured by the oil spill. The Open Ocean Trustees include NOAA, Department of the Interior, U.S. Environmental Protection Agency, and U.S. Department of Agriculture. In 2019, the Open Ocean Trustee Implementation Group committed more than $126 million to implement four restoration projects to address the injury to MDBC. The MDBC projects are: mapping, Ground-truthing, and Predictive Habitat Modeling; Habitat Assessment and Evaluation; Coral Propagation Technique Development; and Active Management and Protection. NOAA and the Department of the Interior are implementing the projects, in cooperation with a range of partners, over eight years. Together, the projects take a phased approach to meet the challenges involved in restoring deep-sea habitats. Challenges to restoration include a limited scientific understanding of these communities, limited experience with restoration at the depths at which these communities occur, and remote locations that limit accessibility. More information about Deepwater Horizon restoration and the MDBC restoration projects is available at: www.gulfspillrestoration.noaa.gov.

Gulf of Mexico↗
USGS2001

Ages and Origins of Calcite and Opal in the Exploratory Studies Facility Tunnel, Yucca Mountain, Nevada

Deposits of calcite and opal are present as coatings on open fractures and lithophysal cavities in unsaturated-zone tuffs at Yucca Mountain, Nevada, site of a potential high-level radioactive waste repository. Outermost layers of calcite and opal have radiocarbon ages of 16,000 to 44,000 years before present and thorium-230/uranium ages of 28,000 to more than 500,000 years before present. These ages are young relative to the 13-million-year age of the host rocks. Multiple subsamples from the same outer layer typically show a range of ages with youngest ages from the thinnest subsamples. Initial uranium-234/uranium-238 activity ratios between 1 and 9.5 show a distinct negative correlation with thorium-230/uranium age and are greater than 4 for all but one sample younger than 100,000 years before present. These data, along with micrometer-scale layering and distinctive crystal morphologies, are interpreted to indicate that deposits formed very slowly from water films migrating through open cavities. Exchanges of carbon dioxide and water vapor probably took place between downward-migrating liquids and upward-migrating gases at low rates, resulting in oversaturation of mineral constituents at crystal extremities and more or less continuous deposition of very thin layers. Therefore, subsamples represent mixtures of older and younger layers on a scale finer than sampling techniques can resolve. Slow, long-term rates of deposition (less than about 5 millimeters of mineral per million years) are inferred from subsamples of outermost calcite and opal. These growth rates are similar to those calculated assuming that total coating thicknesses of 10 to 40 millimeters accumulated over 12 million years. Calcite has a wide range of delta carbon-13 values from about -8.2 to 8.5 per mil and delta oxygen-18 values from about 10 to 21 per mil. Systematic microsampling across individual mineral coatings indicates basal (older) calcite tends to have the largest delta carbon-13 values and smallest delta oxygen-18 values compared to calcite from intermediate and outer positions. Basal calcite has relatively small strontium-87/strontium-86 ratios, between 0.7105 and 0.7120, that are similar to the initial isotopic compositions of the strontium-rich tuff units, whereas outer calcite has more radiogenic strontium-87/strontium-86 ratios between 0.7115 and 0.7127. Isotopic compositions of strontium, oxygen, and carbon in the outer (youngest) unsaturated-zone calcite are coincident with those measured in Yucca Mountain calcrete, which formed by pedogenic processes. The physical and isotopic data from calcite and opal indicate that they formed from solutions of meteoric origin percolating through a limited network of connected fracture pathways in the unsaturated zone rather than by inundation from ascending ground water originating in the saturated zone. Mineral assemblages, textures, and distributions within the unsaturated zone are distinctly different from those deposited below the water table at Yucca Mountain. The calcite and opal typically are present only on footwall surfaces of a small fraction of fractures and only on floors of a small fraction of lithophysal cavities. The similarities in the carbon, oxygen, and strontium isotopic compositions between fracture calcite and soil-zone calcite, as well as the gradation of textures from detritus-rich micrite in the soil to detritus-free spar 10 to 30 meters below the surface, also support a genetic link between the two depositional environments. Older deposits contain oxygen isotope compositions that indicate elevated temperatures of mineral formation during the early stages of deposition; however, in the youngest deposits these values are consistent with deposition under geothermal gradients similar to modern conditions. Correlations between mineral ages and varying Pleistocene climate conditions are not apparent from the current data. Cumulative evidence from calcite and opal deposits indicate

Water-Resources Investigations Report↗
USGS2001

Hydrologic setting and geochemical characterization of free-phase hydrocarbons in the alluvial aquifer at Mandan, North Dakota, November 2000

Free-phase hydrocarbons are present in the alluvial aquifer at Mandan, North Dakota. A large contaminant body of the hydrocarbons [light nonaqueous phase liquid (LNAPL)] floats on the water table about 20 feet below land surface. The main LNAPL body is about 6 feet thick, and the areal extent is about 657,000 square feet. A study was conducted to describe the hydrologic setting and characterize the geochemical composition of the free-phase hydrocarbons in the alluvial aquifer. Most of the study area is underlain by alluvium of the Heart River Valley that ranges in thickness from about 25 to 109 feet. The alluvium can be divided into three stratigraphic units silty clay, silty sand, and sand and is underlain by shales and sandstones. Monitoring wells were installed prior to this study, to an average depth of about 29 feet. Regional ground-water flow in the Heart River aquifer generally may be from west-northwest to eastsoutheast and is influenced by hydraulic connections to the river. Hydraulic connections also are probable between the aquifer and the Missouri River. Ground-water flow across the north boundary of the aquifer is minimal because of adjacent shales and sandstones of relatively low permeability. Recharge occurs from infiltration of precipitation and is spatially variable depending on the thickness of overlying clays and silts. Although the general water-table gradient may be from west-northwest to east-southeast, the flow directions can vary depending on the river stage and recharge events. Any movement of the LNAPL is influenced by the gradients created by changes in water-level altitudes. LNAPL samples were collected from monitoring wells using dedicated bailers. The samples were transferred to glass containers, stored in the dark, and refrigerated before shipment for analysis by a variety of analytical techniques. For comparison purposes, reference-fuel samples provided by the refinery in Mandan also were analyzed. These reference-fuel samples included a current diesel fuel, a closely related but slightly broader refinery-cut fuel, a crude-oil composite, unleaded regular gasoline, and additives. Four principal analytical techniques were used for geochemical characterization: Purge-and-trap gas chromatography/mass spectrometry (volatile components); capillary gas chromatography/mass spectrometry (semivolatile components); isotope ratio mass spectrometry (carbon isotopes; whole oils); and liquid chromatography/mass spectrometry with electrospray ionization (additives and other organic components). Volatile analytes included solvents, disinfection byproducts, halogenated hydrocarbons, and alkylbenzenes, including benzene, toluene, ethylbenzene, and meta-, para-, and orf/zo-xylenes. Semivolatile analytes included rt-alkanes, isoprenoid alkanes, cycloalkanes, and polycyclic aromatic hydrocarbons and related compounds (naphthalenes, phenanthrenes, and dibenzothiophenes and their alkylated derivatives). Of the additives, only the diesel-fuel additive with the red dye marker was amenable to electrospray ionization. Results indicate the LNAPL consists of closely correlatable diesel fuel at various stages of degradation. All LNAPL samples contained the red dye marker for diesel fuel. None of the samples contained chlorinated solvents associated with industries such as drycleaning or automotive maintenance. Solvents such as acetone, dimethyl ether, and methylene chloride and the gasoline additives methyl-t-butyl ether (MTBE), ethyl-t-butyl ether (ETBE), and t-amyl-methyl ether (TAME) were not found. With one possible exception, no evidence of a different diesel or other hydrocarbon fuel contribution was identified. At one site near the north edge of the main LNAPL body, evidence exists for traces of possible gasoline components in addition to the diesel fuel. The geochemical analysis of the LNAPL and correlations with other fuel products and additives strongly suggest episodic releases of a single, local-source, diesel fuel into the aquifer over an extended period of time.

North Dakota↗
USGS2001

Geophysical investigations of well fields to characterize fractured-bedrock aquifers in southern New Hampshire

Bedrock-fracture zones near high-yield bedrock wells in southern New Hampshire well fields were located and characterized using seven surface and six borehole geophysical survey methods. Detailed surveys of six sites with various methods provide an opportunity to integrate and compare survey results. Borehole geophysical surveys were conducted at three of the sites to confirm subsurface features. Hydrogeologic settings, including a variety of bedrock and surface geologic materials, were sought to gain an insight into the usefulness of the methods in varied terrains. Results from 15 survey lines, 8 arrays, and 3 boreholes were processed and interpreted from the 6 sites. The surface geophysical methods used provided physical properties of fractured bedrock. Seismic refraction and ground-penetrating radar (GPR) primarily were used to characterize the overburden materials, but in a few cases indicated bedrock-fracture zones. Magnetometer surveys were used to obtain background information about the bedrock to compare with other results, and to search for magnetic lows, which may result from weathered fractured rock. Electromagnetic terrain conductivity surveys (EM) and very-low-frequency electromagnetic surveys (VLF) were used as rapid reconnaissance techniques with the primary purpose of identifying electrical anomalies, indicating potential fracture zones in bedrock. Direct-current (dc) resistivity methods were used to gather detailed subsurface information about fracture depth and orientation. Two-dimensional (2-D) dc-resistivity surveys using dipole-dipole and Schlumberger arrays located and characterized the overburden, bedrock, and bedrock-fracture zones through analysis of data inversions. Azimuthal square array dc-resistivity survey results indicated orientations of conductive steep-dipping bedrock-fracture zones that were located and characterized by previously applied geophysical methods. Various available data sets were used for site selection, characterizations, and interpretations. Lineament data, developed as a part of a statewide and regional scale investigation of the bedrock aquifer, were available to identify potential near-vertical fracture zones. Geophysical surveys indicated fracture zones coincident with lineaments at 4 of the sites. Geologic data collected as a part of the regional scale investigation provided outcrop fracture measurements, ductile fabric, and contact information. Dominant fracture trends correspond to the trends of geophysical anomalies at 4 of the sites. Water-well drillers? logs from water supply and environmental data sets also were used where available to characterize sites. Regional overburden information was compiled from stratified-drift aquifer maps and surficial-geological maps.

Water-Resources Investigations Report↗
USGS1995

Physical and chemical limnology of Ides Cove near Rochester, New York, 1970-1982

Ides Cove is a small embayment on the western shore of Irondequoit Bay near Rochester, N.Y. In 1982, alum was applied to the cove to seal the bottom sediments and thereby decrease nutrient fluxes in an effort to assess the applicability of this technique to Irondequoit Bay. Published data were used to develop a baseline analysis of the chemical and physical limnology of Ides Cove prior to the alum treatment and to provide a basis for comparison and evaluation of post-treatment data. The baseline analysis also enables evaluation of trends in the nutrient status and mixing patterns in Ides Cove since the decrease of sewage inflows and use of road salt in the Irondequoit Bay and Ides Cove drainage basins during 1970-82. Data from 1970-72 and 1979-82 were used to construct partial and full-year depth profiles of several physical properties and chemical constituents of water in the cove; comparison of these profiles indicates a significant improvement in water quality between 1970 and 1982. The diversion of sewage out of the Irondequoit Creek drainage basin in the late 1970's resulted in an 80-percent decrease in total phosphate concentration and a 50- to 60-percent decrease in nitrogen (nitrate and ammonia) concentration in the cove. Indications of decreased primary productivity are associated with these lowered nutrient concentrations. Summer Secchi-disk transparency increased from 0.6 m (meters) in 1970-72 to 1.2 m in 1980-82; peak epilimnetic dissolved oxygen levels decreased from a range of 22 to 28 mg/L (milligrams per liter) to a range of 16 to 20 mg/L; and peak epilimnetic pH decreased from greater than 9.4 to between 8.8 and 9.0. The decrease in the use of road salt in the Irondequoit basin beginning in 1974 resulted in a decrease in chloride concentration and gradient (difference between the surface and bottom con- centration). The maximum annual chloride concentration in the epilimnion decreased from the 210-to-225-mg/L range in the spring of 1971-72 to the 140-to-l50-mg/L range in the spring of 1980-82, and the gradient between the hypolimnion and epilimnion during the spring decreased from the 80- to 160-mg/L range in 1971-72 to the O- to 90-mg/L range in 1980-82. Specific conductance values decreased similarly and indicate a comparable decrease in the density gradient from 1970-72 to 1980-82. The decrease in the density gradient resulted in an increase in the depth and duration of mixing in both the spring and fall of 1980-82, as illustrated by the profiles of physical properties, including temperature and specific conductance, and of chemical properties and constituents, including pH, alkalinity, dissolved oxygen, chloride, silica, and several species of nitrogen, phosphorus, and sulfur. These data indicate that Ides Cove, which was described as marginally meromictic in the early 1970's, had evolved by the early 1980's into a spring meromictic water body that underwent complete mixing in the fall and was approaching a consistent dimictic condition with spring and fall mixing. Thus, water quality and mixing patterns of the cove improved with the removal of sewage and the decrease in the use of road salt.

Water-Resources Investigations Report↗
USGS2019

Widespread initiation, reactivation, and acceleration of landslides in the northern California Coast Ranges due to extreme rainfall

Episodically to continuously active slow-moving landslides are driven by precipitation. Climate change, which is altering both the frequency and magnitude of precipitation world21 wide, is therefore predicted to have a major impact on landslides. Here we examine the behavior of hundreds of slow-moving landslides in northern California in response to large changes in annual precipitation that occurred between 2016 and 2018. We quantify the landslide displacement using repeat-pass radar interferometry and pixel offset tracking techniques on a novel dataset from the airborne NASA/JPL Uninhabited Aerial Vehicle Synthetic Aperture Radar. We found that 312 landslides were moving due to extreme rainfall during 2017, compared to 119 during 2016, which was the final year of a historic multi-year drought. However, with a return to below average rainfall in 2018, only 146 landslides remained in motion. The increased number of landslides during 2017 was primarily accommodated by landslides that were smaller than the landslides that remained active between 2016 and 2018. Furthermore, by examining a subset of 51 landslides, we found that 49 had increased velocities during 2017 when compared to 2016. Our results show that slow-moving landslides are sensitive to large changes in annual precipitation, particularly the smaller and thinner landslides that likely experience larger basal pore water pressure changes. Based on climate model predictions for the next century in California, which include increases in annual precipitation and increases in the frequency of dry-to-wet extremes, we hypothesize that there will be an overall increase in landslide activity.

California↗
USGS2012

Geophysical investigation of sentinel lakes in Lake, Seminole, Orange, and Volusia Counties, Florida

This study was initiated in cooperation with the St. Johns River Water Management District (SJRWMD) to investigate groundwater and surface-water interaction in designated sentinel lakes in central Florida. Sentinel lakes are a SJRWMD established set of priority water bodies (lakes) for which minimum flows and levels (MFLs) are determined. Understanding both the structure and lithology beneath these lakes can ultimately lead to a better understanding of the MFLs and why water levels fluctuate in certain lakes more so than in other lakes. These sentinel lakes have become important water bodies to use as water-fluctuation indicators in the SJRWMD Minimum Flows and Levels program and will be used to define long-term hydrologic and ecologic performance measures. Geologic control on lake hydrology remains poorly understood in this study area. Therefore, the U.S. Geological Survey investigated 16 of the 21 water bodies on the SJRWMD priority list. Geologic information was obtained by the tandem use of high-resolution seismic profiling (HRSP) and direct-current (DC) resistivity profiling to isolate both the geologic framework (structure) and composition (lithology). Previous HRSP surveys from various lakes in the study area have been successful in identifying karst features, such as subsidence sinkholes. However, by using this method only, it is difficult to image highly irregular or chaotic surfaces, such as collapse sinkholes. Resistivity profiling was used to complement HRSP by detecting porosity change within fractured or collapsed structures and increase the ability to fully characterize the subsurface. Lake Saunders (Lake County) is an example of a lake composed of a series of north-south-trending sinkholes that have joined to form one lake body. HRSP shows surface depressions and deformation in the substrate. Resistivity data likewise show areas in the southern part of the lake where resistivity shifts abruptly from approximately 400 ohm meters (ohm-m) along the edges to approximately 12 ohm-m in the center. These well-defined areas may indicate a "ravel" zone of increased porosity or clay content. Within Lake Helen (Volusia County), a parallel set of seismic reflectors within a host of chaotic reflectors may represent fill within a large sinkhole. The feature extends to more than 50 meters (m) deep and contains very steep pinnacles within the center. Seismic data in Lake Helen are supported by high resistivity values from adjacent continuous resistivity profiles that show possible center collapse within the lake and infilling of sandy material. When used together, HRSP and DC resistivity techniques provide a composite image of structure and lithology to detect potential conduits for fluid flow.

Florida↗
USGS1997

Glacier ice-volume modeling and glacier volumes on Redoubt Volcano, Alaska

Assessment of ice volumes and hydrologic hazards on Redoubt Volcano began four months before the 1989-90 eruptions removed 0.29 cubic kilometer of perennial snow and ice from Drift glacier. A volume model was developed for evaluating glacier volumes on Redoubt Volcano. The volume model is based on third-order polynomial simulations of valley cross sections. The third-order polynomial is an interpolation from the valley walls exposed above glacier surfaces and takes advantage of ice-thickness measurements. The fortuitous 1989-90 eruptions removed the ice from a 4.5-kilometer length of Drift glacier, providing a unique opportunity for verification of the volume model. A 2.5-kilometer length was chosen in the denuded glacier valley and the ice volume was measured by digitally comparing two new maps: one derived from the most recent pre-eruption 1979 aerial photographs and the other from post-eruption 1990 aerial photographs. The measured volume in the reference reach was 99 x 106 cubic meters, about 1 percent less than was estimated by the volume model. The volume estimate produced by this volume model was much closer to the measured volume than was the volume estimated by other techniques. The verified volume model was used to evaluate the total volume of perennial snow and glacier ice on Redoubt Volcano, which was estimated to be 4.1?0.8 cubic kilometers. Substantial snow and ice covers on volcanoes exacerbate the hydrologic hazards associated with eruptions. The volume on Redoubt Volcano is about 23 times the volume that was present on Mount St. Helens before its 1980 eruption, which generated lahars and floods.

Water-Resources Investigations Report↗
USGS1975

Geochemical Exploration Techniques Applicable in the Search for Copper Deposits

Geochemical exploration is an important part of copper-resource evaluation. A large number of geochemical exploration techniques, both proved and untried, are available to the geochemist to use in the search for new copper deposits. Analyses of whole-rock samples have been used in both regional and local geochemical exploration surveys in the search for copper. Analyses of mineral separates, such as biotite, magnetite, and sulfides, have also been used. Analyses of soil samples are widely used in geochemical exploration, especially for localized surveys. It is important to distinguish between residual and transported soil types. Orientation studies should always be conducted prior to a geochemical investigation in a given area in order to determine the best soil horizon and the best size of soil material for sampling in that area. Silty frost boils, caliche, and desert varnish are specialized types of soil samples that might be useful sampling media. Soil gas is a new and potentially valuable geochemical sampling medium, especially in exploring for buried mineral deposits in arid regions. Gaseous products in samples of soil may be related to base-metal deposits and include mercury vapor, sulfur dioxide, hydrogen sulfide, carbon oxysulfide, carbon dioxide, hydrogen, oxygen, nitrogen, the noble gases, the halogens, and many hydrocarbon compounds. Transported materials that have been used in geochemical sampling programs include glacial float boulders, glacial till, esker gravels, stream sediments, stream-sediment concentrates, and lake sediments. Stream-sediment sampling is probably the most widely used and most successful geochemical exploration technique. Hydrogeochemical exploration programs have utilized hot- and cold-spring waters and their precipitates as well as waters from lakes, streams, and wells. Organic gel found in lakes and at stream mouths is an unproved sampling medium. Suspended material and dissolved gases in any type of water may also be useful media. Samples of ice and snow have been used for limited geochemical surveys. Both geobotanical and biogeochemical surveys have been successful in locating copper deposits in many parts of the world. Micro-organisms, including bacteria and algae, are other unproved media that should be studied. Animals can be used in geochemical-prospecting programs. Dogs have been used quite successfully to sniff out hidden and exposed sulfide minerals. Tennite mounds are commonly composed of subsurface material, but have not as yet proved to be useful in locating buried mineral deposits. Animal tissue and waste products are essentially unproved but potentially valuable sampling media. Knowledge of the location of areas where trace-element-associated diseases in animals and man are endemic as well as a better understanding of these diseases, may aid in identifying regions that are enriched in or depleted of various elements, including copper. Results of analyses of gases in the atmosphere are proving valuable in mineral-exploration surveys. Studies involving metallic compounds exhaled by plants into the atmosphere, and of particulate matter suspended in the atmosphere are reviewed these methods may become important in the future. Remote-sensing techniques are useful for making indirect measurements of geochemical responses. Two techniques applicable to geochemical exploration are neutron-activation analysis and gamma-ray spectrometry. Aerial photography is especially useful in vegetation surveys. Radar imagery is an unproved but potentially valuable method for use in studies of vegetation in perpetually clouded regions. With the advent of modern computers, many new techniques, such as correlation analysis, regression analysis, discriminant analysis, factor analysis, cluster analysis, trend-surface analysis, and moving-average analysis can be applied to geochemical data sets. Selective use of these techniques can provide new insights into the interpretatio

Professional Paper↗
USGS2000

Microbiological and chemical quality of ground water used as a source of public supply in southern Missouri — Phase II, April–July, 1998

The protection of public health through quality public ground-water systems is the responsibility of the U. S. Environmental Protection Agency and the State of Missouri, through the Missouri Department of Natural Resources, Public Drinking Water Program. Approximately 95 percent of the public-water supplies in Missouri use ground water as their source of drinking water through more than 3,700 public wells. Karst terrain, intensive agricultural operations, extensive numbers of on-site sewage systems, and poor well construction can lead to chemical and microbiological contamination of the contributing aquifers. Sitespecific studies and routine regulatory monitoring have produced information on the overall quality and potability of the State's public-drinking-water supplies, but little is known about the presence of viruses. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, sampled 109 public-water supplies to characterize the physical, chemical, bacterial, and viral conditions in southern Missouri. During April to July 1998, these wells were sampled for nutrients, total organic carbon, optical brighteners, indicator bacteria, enteric viruses, and ribonucleic acid and somatic coli phages. These constituents indicate possible surface contamination of the sampled aquifer. Selection of the wells to be sampled depended on the age of the well (pre-1970), land use, geohydrology, and well construction. None of the physical or chemical constituents measured or analyzed exceeded Missouri's Drinking Water Standards set by the Public Drinking Water Program of the Missouri Department of Natural Resources. The majority of ammonia plus organic nitrogen, nitrite, and phosphorus concentrations were below the laboratory's minimum reporting levels. There were a greater number of detects above the minimum reporting level with respect to the nitrite plus nitrate, ammonia, orthophosphate, and total organic carbon concentrations. Analyses included comparing and contrasting the data by grouping according to well age and construction, karst type, geohydrology, soil type, and land use. There was little variation in well construction between selected wells. The results indicated several groupings of similar and dissimilar concentrations, most expected because of hydrological, physical, or land use differences. Dissolved oxygen values indicated distinct variation in the different groupings. There were significant differences in dissolved oxygen values between the secondary and non-karst areas, the Ozark confined and Ozark unconfined geohydrologic groups, and between agricultural and other land uses. In groupings by soil and geohydrology, the Missouri bootheel region differed with respect to ammonia, total organic carbon, and phosphorus when compared with the other groups. Less than 10 percent of the wells sampled tested positive for bacterial contamination. E. coli was the most frequently detected bacterium. The public wells at Monett and West Plains, Missouri, had plates with colonies too numerous to count for all three indicator bacteria. Further analyses by rRNA (ribosomal RiboNucleic Acid) hybridization techniques detennined that much of the bacteria present were from ruminant and human sources. No enteric viruses were detected in the 109 samples. Both ribonucleic acid and somatic coliphage were detected at two wells. One additional well had ribonucleic acid coliphage and another had somatic coliphage for a total of four wells with coliphage selects.

Missouri↗
USGS2009

Water use in Georgia by county for 2005; and water-use trends, 1980-2005

Water use for 2005 for each county in Georgia was estimated using data obtained from various Federal and State agencies and local sources. Total consumptive water use also was estimated for each county in Georgia for 2005. Estimates of offstream water use include the categories of public supply, domestic, commercial, industrial, mining, irrigation, livestock, and thermoelectric power. The only category of instream use estimated was hydroelectric-power generation. Total offstream water use from ground- and surface-water sources was about 5,471 million gallons per day (Mgal/d) in 2005. Surface water used in the process of thermoelectric-power generation was the largest volume of water withdrawn with withdrawals of 2,717 Mgal/d in 2005. Estimated instream water use for hydroelectric-power generation was 54,096 Mgal/d. Withdrawals for irrigation totaled 752 Mgal/d with 65 percent supplied by ground-water sources. Surface water provided 78 percent of the 1,180 Mgal/d withdrawn for public supply. Many counties in the northern Piedmont physiographic province of Georgia, an area of dense population, had a large percentage of withdrawals from surface-water sources. In contrast, in the southern Coastal Plain physiographic province part of the State, many counties had more withdrawals from ground-water sources. As part of the Georgia Water-Use Program, statewide water-use estimates have been compiled every 5 years since 1980. During this period, water use was greatest in 1980 at 6,725 Mgal/d. Water use decreased by 31 percent to 5,353 Mgal/d in 1990 then increased to 6,487 Mgal/d in 2000. By 2005, water withdrawals had decreased to an estimated 5,471 Mgal/d primarily because of a decline in withdrawals for thermoelectric-power generation and a decline in demands as 2005 was a normal year for precipitation compared to 2000, which was in drought. Throughout the period 1980–2005, water withdrawn for thermoelectric-power generation made up the largest volume of offstream water use in Georgia. Total withdrawals for thermoelectric-power generation decreased about 24 percent in 2005 compared to 2000, due to the decommissioning of three power plants in the State. In addition, several plants operated by Georgia Power Company were retooled during this period to increase water conservation. Public-supply use steadily increased from 1980 to 2000, concurrent with increasing population in the State; however, in 2005, there was a slight decrease in public-supply use. Conversely, industrial water use decreased during the period 1980–2005. Water withdrawals for irrigation during 1980–2005 followed changing hydrologic conditions, increasing during drier years (1980 and 2000) and decreasing during normal or wetter years. Withdrawals for the categories of domestic and commercial use remained about the same during 1980–2005. Livestock and mining use increased in 2005 compared to the 2000 estimates because of changes in estimation techniques. Consumptive water use was determined for each category of use and compiled for each county. Estimation techniques vary for each water-use category. While consumptive use varied for each county in 2005, from about 1 percent to nearly 100 percent of total withdrawals, consumptive-use estimates for the entire State totaled 1,310 Mgal/d, about 24 percent of total withdrawals.

Georgia↗
USGS1998

Mercury concentrations in estuarine sediments, Lavaca and Matagorda bays, Texas, 1992

A preliminary assessment of the distribution and variability of total mercury concentrations in five sediment environments—open water, ship channel, dredged spoil, oyster reef, and salt marsh—of the Lavaca-Matagorda Bays estuarine system along the central Texas Gulf Coast shows that the largest total mercury concentrations in the bays are in the 10- to 20-centimeter sample-depth zone in 2 of the 3 sample areas (1 open water and 1 salt marsh) closest to Point Comfort. The concentrations range from 137 to 1,270 micrograms per kilogram in the open-water environment and 73.8 to 1,900 micrograms per kilogram in the saltmarsh environment. In the surface-sample-depth zones among all sediment environments, total mercury concentrations typically are largest in the open-water environment and smallest in the dredged-spoil and salt-marsh environments. Open-water sample areas 1–01, 1–02 (middle Lavaca Bay), and 1–06 (upper Matagorda Bay) have median total mercury concentrations in all three sample-depth zones (0 to 2, 10 to 20, and 20 to 50 centimeters) greater than detection limits. Median concentrations for the different depth zones in the three sample areas range from 30.5 to 705 micrograms per kilogram. Statistical tests indicate that in all three sample-depth zones in open-water sediments, median total mercury concentrations in some sample areas are significantly different from median total mercury concentrations in other sample areas. Another statistical test indicates that the variance in concentrations of open-water samples collected within 10 meters of each other is the same as the variance in concentrations of samples collected randomly within each 1 square kilometer. However, the degree to which a probable lack of independence among the closely spaced data affects the test result is not known. Rank correlation coefficients between total mercury concentration and grain-size fractions (percentages of sand, silt, clay, and silt plus clay) and between total mercury concentration and total organic carbon concentration for open-water sample areas indicate that total mercury concentration has a significant positive correlation with clay percentage in 4 of the 8 open-water sample areas. In 6 of the 8 open-water sample areas, total mercury concentration has a significant positive correlation with silt-plus-clay percentage and total organic carbon concentration. The use of a technique known as kriging to estimate total mercury concentrations at unmeasured sites on the basis of sampling sites where mercury concentrations are measured in openwater sediments in the 0- to 2-centimeter sampledepth zone was explored. Kriging to estimate concentrations in the areas between clusters of sample data points is not a practical solution for obtaining a distribution of concentrations in the bays. U.S. Environmental Protection Agency Method 7471 (Cold Vapor Atomic Absorption) was an acceptable analytical method for determining the total mercury concentrations in the Lavaca-Matagorda Bays estuarine sediment samples. Measurement of additional trace metals would aid in the characterization of total mercury concentrations and in the identification of concentrator/collector relations that are principally responsible for the adsorption of mercurous compounds to particulates in the bottom sediments.

Texas↗
USGS1975

Preliminary hydrogeologic appraisal of selected hydrothermal systems in northern and central Nevada

Several hydrothermal systems in northern and central Nevada were explored in a hydrogeologic reconnaissance. The systems studied comprise those at Stillwater and Soda Lakes-Upsal Hogback in the Carson Desert, Gerlach, Fly Ranch-Granite Range, and Double Hot Springs in the Black Rock Desert, Brady's Hot Springs, Leach Hot Springs in Grass Valley, Buffalo Valley Hot Springs, and Sulphur Hot Springs in Ruby Valley. The investigation focused on (1) delineating of areas of high heat flow associated with rising thermal ground water, (2) determining the nature of the discharge parts of the hydrothermal systems, (3) estimating heat discharge from the systems, (4) estimating water discharge from the systems, (5) obtaining rough estimates of, conductive heat flow outside areas of hydrothermal discharge, and (6) evaluating several investigative techniques that would yield the required information quickly and at relatively low cost. The most useful techniques were shallow test drilling to obtain geologic, hydraulic, and thermal data and hydrogeologic mapping of the discharge areas. The systems studied are in the north-central part of the Basin and Range province. Exposed volcanic rocks of latest Tertiary and Quaternary age are chiefly basaltic. Basaltic terranes are generally regarded as less favorable for geothermal resources than terranes that contain large volumes of young volcanic mocks of felsic to intermediate composition. Most of the known hydrothermal systems are associated with Basin and Range faults which are caused by crustal extension across the province. An area of high heat flow centered at Battle Mountain and possibly other areas of high heat flow may be related to crustal heat sources. However, some of the hydrothermal systems studied appear to be related to deep circulation of meteoric water in areas of 'normal' regional heat flow rather than to shallow-crustal heat sources. Discharge temperatures of thermal springs in the region range from slightly above mean annual air temperature (8?-12?C at most places) to boiling or slightly hotter. Geochemical data indicate that, in the major systems, subsurface temperatures at which thermal waters equilibrate with reservoir rocks range from 150? to more than 200?C. These data also indicate that the major systems are of the hot-water type rather than the vapor-dominated type. Depths of thermal-water circulation probably range from 2 to 6 kilometres in areas of 'normal' regional heat flow (~2 heatflow units) and from 1 to 3 kilometres in areas of high heat flow (~3-4 heat-flow units) such as near Battle Mountain. Most of the heat is discharged from the hydrothermal systems studied by (1) conduction through near-surface materials heated as a consequence of thermal-water convection, (2) convection as springflow, and (3) convection as steam discharge from spring pools, vents, fumaroles, and cracks. The mate of heat discharge by radiation from warm ground and by convection as lateral ground-water outflow is believed to be small in most systems and is not estimated. Estimates of net heat discharge from the systems studied range from about 0.8 x 106 calories per second at Buffalo Valley Hot Springs to about 14 x 106 calories per second at Stillwater. These estimates represent the approximate magnitude of the excess heat discharge from the thermal areas that results from the upward convection of hot water from deep sources. Water discharges from the hydrothermal systems by springflow, evapotranspiration, steam discharge, and lateral ground-water outflow. Estimated discharges range from about 0.2 x 106cubic metres per year from the Buffalo Valley Hot Springs system to about 3 x 106 cubic metres per year from the Stillwater system. In most of the hydrothermal systems studied and, by inference, in other similar systems in northern and central Nevada, the scale for potential .commercial development for production of electricity or for other uses may be constrained by the

Open-File Report↗
USGS2022

The use of continuous sediment-transport measurements to improve sand-load estimates in a large sand-bedded river: The Lower Chippewa River, WI

Accurately determining sediment loads is necessary for managing river environments but is difficult because multiple processes can lead to large discharge-independent changes in sediment transport. Thus, estimations of sediment load using discharge–sediment rating curves fit to sparse or historical sediment-transport measurements can be inaccurate, necessitating alternative approaches to reduce uncertainty. Continuous sediment-transport measurements reduce uncertainty because they can be used to detect discharge-independent changes in transport and are therefore unaffected by hysteresis. We used largely continuous approaches to measure sand transport in the lower Chippewa River, a large sand-supplying tributary to the Mississippi River. We used side-looking acoustic-Doppler profilers to continuously measure suspended-sand concentration, and bedform-tracking techniques to episodically measure bedload transport. Bedload transport was then continuously estimated using a discharge-dependent ratio of bedload to suspended-sand transport. This approach allowed determination of sand loads that were not estimated based only on water discharge. Our continuous suspended-sand measurements show that hysteresis between discharge and suspended-sand concentration occurs during most floods. Quasi-continuous bed-elevation measurements using a scour monitor show that lags between discharge and dune geometric adjustment is also common, causing hysteresis between discharge and bedload transport during floods. Furthermore, comparisons of our measurements with historical sediment-transport measurements indicate large discharge-independent declines in both suspended-sand and bedload transport since the 1980s. These findings indicate that sand transport is a non-stationary function of water discharge over timescales ranging from within individual floods to decades. Consequently, although our continuous-measurement approach yields only a ~20–30% improvement over rating-curve estimates of sand load over multi-year periods, our approach yields up to a factor-of-five improvement in sand-load estimates over the shorter, i.e., within a flood, timescales over which the largest discharge-independent changes in sand transport occur.

Wisconsin↗
USGS2018

Inland waters

1. The total flux of carbon—which includes gaseous emissions, lateral flux, and burial—from inland waters across the conterminous United States (CONUS) and Alaska is 193 teragrams of carbon (Tg C) per year. The dominant pathway for carbon movement out of inland waters is the emission of carbon dioxide gas across water surfaces of streams, rivers, and lakes (110.1 Tg C per year), a flux not identified in the First State of the Carbon Cycle Report (SOCCR1; CCSP 2007). Second to gaseous emissions are the lateral fluxes of carbon through rivers to coastal environments (59.8 Tg C per year). Total carbon burial in lakes and reservoirs represents the smallest flux for CONUS and Alaska (22.5 Tg C per year) (medium confidence). 2. Based on estimates presented herein, the carbon flux from inland waters is now understood to be four times larger than estimates presented in SOCCR1. The total flux of carbon from inland waters across North America is estimated to be 507 Tg C per year based on a modeling approach that integrates high-resolution U.S. data and continental-scale estimates of water area, discharge, and carbon emissions. This estimate represents a weighted average of 24 grams of carbon per m2 per year of continental area exported and removed through inland waters in North America (low confidence). 3. Future research can address critical knowledge gaps and uncertainties related to inland water carbon fluxes. This chapter, for example, does not include methane emissions, which cannot be calculated as precisely as other carbon fluxes because of significant data gaps. Key to reducing uncertainties in estimated carbon fluxes is increased temporal resolution of carbon concentration and discharge sampling to provide better representations of storms and other extreme events for estimates of total inland water carbon fluxes. Improved spatial resolution of sampling also could potentially highlight anthropogenic influences on the quantity and quality of carbon fluxes in inland waters and provide information for land-use planning and management of water resources. Finally, uncertainties could likely be reduced if the community of scientists working in inland waters establishes and adopts standard measurement techniques and protocols similar to those maintained through collaborative efforts of the International Ocean Carbon Coordination Project and relevant governmental agencies from participating nations.

Book chapter↗