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USGS1960

Methods for collection and analysis of water samples

This manual contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water samples. Throughout, the emphasis is on obtaining analytical results that accurately describe the chemical composition of the water in situ. Among the topics discussed are selection of sampling sites, frequency of sampling, field equipment, preservatives and fixatives, analytical techniques of water analysis, and instruments. Seventy-seven laboratory and field procedures are given for determining fifty-three water properties.

Water Supply Paper↗
USGS1997

Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Samples were collected from 5 drinking-water wells, 12 springs, and 1g3 monitoring wells in urban areas. No MTBE was detected in drinking-water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in 8 areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in 9 areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft lifetime drinking water health advisory. Because MTBE is persistent and mobile in groundwater) it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylenes (BTEX) compounds which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and nonpoint sources, such as recharge of precipitation and storm-water runoff.

ACS Division of Environmental Chemistry, Preprints↗
USGS2005

Design, implementation, and initial results from a water-quality monitoring network for Atlanta, Georgia, USA

In cooperation with the City of Atlanta, Georgia, the US Geological Survey has designed and implemented a water-quantity and quality monitoring network that measures a variety of biological and chemical constituents in water and suspended sediment. The network consists of 20 long-term monitoring sites and is intended to assess water-quality trends in response to planned infrastructural improvements. Initial results from the network indicate that nonpoint-source contributions may be more significant than point-source contributions for selected sediment associated trace elements and nutrients. There also are indications of short-term discontinuous point-source contributions of these same constituents during baseflow.

Conference Paper↗
USGS1977

Chemical dissolution of sulfide minerals

Chemical dissolution treatments involving the use of aqua regia, 4 N HNO 3 , H 2 O 2 -ascorbic acid, oxalic acid, KClO 3 +HCl, and KClO 3 +HCl followed by 4 N HNO 3 were applied to specimens of nine common sulfide minerals (galena, chalcopyrite, cinnabar, molybdenite, orpiment, pyrite, stibnite, sphalerite, and tetrahedrite) mixed individually with a clay loam soil. The resultant decrease in the total sulfur content of the mixture, as determined by using the Leco induction furnace, was used to evaluate the effectiveness of each chemical treatment. A combination of KClO 3 +HCl followed by 4 N HNO 3 boiling gently for 20 min has been shown to be very effective in dissolving all the sulfide minerals. This treatment is recommended to dissolve metals residing in sulfide minerals admixed with secondary weathering products, as one step in a fractionation scheme whereby metals in soluble and adsorbed forms, and those associated with organic materials and secondary oxides, are first removed by other chemical extractants.

Journal of Research of the U.S. Geological Survey↗
USGS2006

Comprehensive water quality of the Boulder Creek Watershed, Colorado, during high-flow and low-flow conditions, 2000

Executive Summary The Boulder Creek Watershed, Colorado, is 1160 square kilometers in area and ranges in elevation from 1480 to 4120 meters above sea level. Streamflow originates primarily as snowmelt near the Continental Divide, and thus discharge varies seasonally and annually (Chapter 1). Most of the water in Boulder Creek is diverted for domestic, agricultural, and industrial use. Some diverted water is returned to the creek as wastewater effluent and by ditch returns, and additional water enters as groundwater and by transbasin diversions. These diversions and returns lead to complex temporal and spatial variations in discharge. The variations in discharge, along with natural factors such as geology and climate, and anthropogenic factors such as wastewater treatment, agriculture, mining, and urbanization, can affect water chemistry. As with many watersheds in the American West, dependable water quality and sufficient water supply are issues facing local water managers and users. Detailed water-quality and sediment sampling allows the identification of sources and sinks of chemical constituents and an understanding of the processes at work in a river system. This study, the most comprehensive water-quality analysis performed for Boulder Creek to date, was a cooperative effort of the U.S. Geological Survey (USGS) and the city of Boulder. Geographic information systems and modeling programs were used to delineate watershed boundaries, land cover, and geology (Chapter 2). During high-flow (June 2000) and low-flow (October 2000) conditions, researchers evaluated 226 water-quality variables, including basic water-quality indicators (Chapter 3), major ions and trace elements (Chapter 4), wastewater-derived organic compounds (Chapter 5), and pesticides (Chapter 6). Discharge (Chapter 1) and bed-sediment particle size and mineralogy (Chapter 7) were also evaluated. This cooperative study was facilitated by the Boulder Area Sustainability Information Network (BASIN), which provides public access to environmental information about the Boulder Creek Watershed on a website, www.basin.org. In addition to the USGS and city of Boulder data, researchers at the Institute of Arctic and Alpine Research at the University of Colorado provided water chemistry data for the headwaters of North Boulder Creek, upstream of the reach of the USGS/city of Boulder sampling sites (Chapter 8). Snowmelt produces high flows in Boulder Creek in late spring to early summer (Chapter 1). Because precipitation falling in the headwaters is very dilute (specific conductance about 5 microsiemens per centimeter), most chemical constituents are present in lower concentrations during high flows (Chapters 3, 4, 5, 6, and 8). However, concentrations of some constituents, such as total suspended solids (Chapter 3) and organic carbon (Chapter 5), increase during the spring snowmelt flush. The upper basin, which consists of alpine, subalpine, montane, and foothills regions west of the mouth of Boulder Canyon, is underlain by Precambrian igneous and metamorphic rocks (Chapter 1). Major dissolved inorganic constituents in headwater sites were found to be enriched by factors of 10 to 20 relative to precipitation; this is consistent with minor weathering of the local crystalline bedrock (Chapter 4). Some anthropogenic input is observed in the headwaters; precipitation introduces nitrogen derived from fossil fuel combustion and agricultural activities (Chapter 8). The lower basin, which consists of the plains region east of the mouth of Boulder Canyon, is underlain by Mesozoic sedimentary rock and Quaternary alluvium, and has substantially more anthropogenic sources. Concentrations of most dissolved inorganic constituents increased in the lower basin. Differentiation between natural and anthropogenic sources of some dissolved constituents is difficult because both sources contribute to the water composition in this region. The increase of most major constituents (bicarbonate, calcium, chloride, magnesium, sodium, and sulfate) is consistent with weathering of the underlying sedimentary bedrock (Chapter 4). It is likely that anthropogenic loading of constituents in this reach occurs during storm events. Fecal coliform concentrations were variable and in some cases exceeded state standards, primarily during low-flow conditions (Chapter 3). Effluent from Boulder’s 75th Street Wastewater Treatment Plant (WWTP) has a substantial impact on the water chemistry of lower Boulder Creek. The WWTP increases the concentrations of nutrients such as nitrogen and phosphorus (Chapter 3), major ions and trace metals (Chapter 4), and organic carbon (Chapter 5) in Boulder Creek. The effluent contained a spike in gadolinium, a rare earth element that is ingested for magnetic resonance imaging as a contrasting agent and then excreted to the urban wastewater system. The effluent also contained trace organic compounds such as surfactants, pharmaceuticals, hormones (Chapter 5), and pesticides (Chapter 6), which also were detected at downstream Boulder Creek sites. Water chemistry of Boulder Creek downstream of the WWTP is largely controlled by the degree of dilution of the wastewater effluent, which varies depending on the baseflow of Boulder Creek, the volume of wastewater effluent, and depletion by agricultural diversions. Coal Creek, a tributary of Boulder Creek, contains wastewater effluent from four additional WWTPs, and increases the load of many constituents in Boulder Creek. In addition to the impact from wastewater effluent, lower Boulder Creek is affected by agricultural land use. Eleven of 84 analyzed pesticides were detected in Boulder Creek or its inflows, primarily in the eastern section of the watershed (Chapter 6). This collaborative study provides an in-depth evaluation of the hydrology, water chemistry, and sediment mineralogy of North Boulder Creek, Middle Boulder Creek, Boulder Creek, and major inflows. The detailed sampling and analysis in this report provide a baseline for future reference, as well as information on the effect of land use and geology on water chemistry.

Colorado↗
USGS1996

Hydrologic data for the East Poplar oil field, Fort Peck Indian Reservation, Northeastern Montana

This report presents selected hydrologic data for the East Poplar oil field, located in the south-central part of the Fort Peck Indian Reservation in northeastern Montana. Data about the occurrence, quantity, and quality of ground and surface water are presented in tabular form. The tables contain records of privately owned wells (active and abandoned), monitoring wells installed by the U.S. Geological Survey and Montana Bureau of Mines and Geology, oil wells, and brine-injection wells; lithologic descriptions of drill cuttings and well-completion data from monitoring wells; data from two aquifer tests conducted in Quaternary alluvial and glacial deposits; chemical quality of ground water; and information on the quantity and chemical quality of surface water. Records of electromagnetic geophysical measurements collected throughout an area of about 20 square miles of the study area are compiled and included on a floppy disk. Illustrations in this report contain information about study area location, site- numbering system, general physical and cultural features, and construction of monitoring wells installed by the U.S. Geological Survey. plate-sized map presents additional information about privately owned wells, monitoring wells, oil wells, brine-injections wells, surface-water data-collection sites, and area of electromagnetic data collection. The data presented in this report provide a base with which to better define and interpret the occurrence, quantity, and quality of ground and surface water in the vicinity of the Poplar River Valley in the south-central part of the Fort Peck Indian Reservation. The data can be used to help delineate the occurrence of brine and saline water in Quaternary alluvial and glacial deposits in the East Poplar oil field.

Open-File Report↗
USGS2012

Water quality and landscape processes of four watersheds in eastern Puerto Rico

Humid tropical regions occupy about a quarter of Earth's land surface, yet they contribute a substantially higher fraction of the water, solutes, and sediment discharged to the world's oceans. Nearly half of Earth's population lives in the tropics, and development stresses can potentially harm soil resources, water quality, and water supply and in addition increase landslide and flood hazards. Owing to Puerto Rico's steep topography, low water storage capacity, and dependence on trade-wind precipitation, the island's people, ecosystems, and water supply are vulnerable to extreme weather such as hurricanes, floods, and droughts. Eastern Puerto Rico offers a natural laboratory for separating geologic and land-cover influences from regional- and global-scale influences because of its various bedrock types and the changing land cover surrounding intact, mature forest of the Luquillo Experimental Forest. Accordingly, a multiyear assessment of hydrological and biogeochemical processes was designed to develop an understanding of the effects of these differences on local climate, streamflow, water quality, and ecosystems, and to form the basis for a long-term and event-based program of climate and hydrologic monitoring. Because infrequent, large storms play a major role in this landscape, we focused on high-runoff events, sampling 263 storms, including all major hurricanes from 1991 through 2005. The largest storms have profound geomorphic consequences, such as landslides, debris flows, deep gullying on deforested lands, excavation and suspension of sediment in stream channels, and delivery of a substantial fraction of annual stream sediment load. Large storms sometimes entrain ocean foam and spray causing high concentrations of seasalt-derived constituents in stream waters during the storm. Past deforestation and agricultural activities in the Cayaguás and Canóvanas watersheds accelerated erosion and soil loss, and this material continues to be remobilized during large storms. Nearly 5,000 routine and event samples were analyzed for parameters that allow determination of denudation rates based on suspended and dissolved loads; 860 of these samples were analyzed for a comprehensive suite of chemical constituents. The rivers studied are generally similar in water-quality characteristics, and windward or leeward aspect appears to exert a stronger influence on water quality than geology or land cover. Of samples analyzed for comprehensive chemistry and for sediment, 543 were collected at runoff rates greater than 1 millimeter per hour, 256 at rates exceeding 10 millimeters per hour, and 3 at rates exceeding 90 millimeters per hour. Streams have rarely been sampled during events with such high runoff rates. Rates of physical and chemical weathering are especially high, and physical denudation rates, forested watersheds included, are considerably greater than is expected for a steady-state system. The elevated physical erosion drives an increased particulate organic carbon flux, one that is large, important to the carbon cycle, and sustainable, because soil-carbon regeneration is rapid. The 15-year Water, Energy, and Biogeochemical Budget dataset, which includes discharge, field parameters, suspended sediment, major cations and anions, and nutrients, is available from the U.S. Geological Survey's National Water Information System (http://waterdata.usgs.gov/nwis). The dataset provides a baseline for characterizing future environmental change and will improve our understanding of the interdependencies of land, water, and biological resources and their responses to changes in climate and land use. Because eastern Puerto Rico resembles many tropical regions in terms of geology and patterns of development, implications from this study are transferable to other tropical regions facing deforestation, rapid land-use change, and climate change.

Puerto Rico↗
USGS1992

Manganese carbonate mineralization in the Molango district, Mexico

The Molango manganese deposit in Mexico is by far the largest known Mn deposit in North America. Mn carbonate mineralization is hosted by a finely laminated Upper Jurassic marine sedimentary sequence that forms the base of the Chipoco facies of the Taman Formation (Kimmeridgian). Manganese enrichment occurs over a total stratigraphic thickness of approximately 50 m, and a length of over 50 km along strike and serves as the protore for supergene Mn oxide ore. The carbonate ore zone comprises the basal 1 to 10 m of the Chipoco facies.The carbonate ore bed consists of fine-grained rhodochrosite and dispersed organic matter, magnetite, and maghemite but generally only trace quantities of pyrite. Fine laminations and clotted textures suggest deposition in a restricted marine environment. Manganese content is highest at the base of the mineralized interval, drops abruptly to subore grade, Mn-rich carbonates, and then gradually decreases upward to background levels (i.e., trace Mn in calcite). Chemical and mineralogical studies indicate that the predominant mineralogy changes upward from rhodochrosite in the ore zone, to mixed carbonates (Mn calcite, kutnohorite, + or - rhodochrosite), to Mn calcite.Several geologic and geochemical processes resulted in the formation of Mn carbonate by the early diagenetic reduction of Mn oxides through the oxidation of organic matter and iron sulfide. Mn oxides were concentrated at the margins of a dysaerobic to mildly anoxic stratified basin and became an important oxidizing agent of organic matter in the sediment pile. Effects of organic matter oxidation reactions included production of manganous ion (Mn (super +2) ), MnCO 3 precipitation, oxidation of iron monosulfide (precursor to pyrite), and formation of Fe oxide. The latter two processes explain the anomalously low pyrite and abundant magnetite content in the ore zone. The observed vertical variation of Mn carbonate mineralogy and the mineral compositions reflect variations in the concentrations of reduced manganese in the pore waters. Thus, Mn carbonate precipitated from pore water and did not form as a chemical sediment in the water column. The ultimate source of the manganese is uncertain but may have been fluvial-sediment loads or hydrothermal activity associated with the rifting of the Gulf of Mexico.

Economic Geology↗
USGS2008

Ground-water-flow modeling of a freshwater and brine-filled aquifer in the Onondaga Trough, Onondaga County, New York: A summary of findings

In 2007, the U.S. Geological Survey (USGS) completed a hydrogeologic study that included the development of a groundwater-flow model of the glacial-drift aquifer in the Onondaga Trough near Syracuse, N.Y., which extends from the Valley Heads Moraine near Tully, N.Y., to Onondaga Lake (fig. 1). Glacial sediments within the Onondaga Trough contain freshwater, saline water, and brine, which has historically supported several chemical industries in Syracuse. The ground-water-flow model was developed as a means to assist the members of the Onondaga Lake Partnership (local, State, and Federal governmental agencies) to assess remediation plans for Onondaga Lake and the Onondaga Creek watershed. Prior to this study, in the late 1990s, very little information was known about the physical nature of the valley-fill aquifer or the quality of water within it. Acquisition of this information would help local agencies understand the interactions of fresh and saline water within the aquifer and Onondaga Lake, and would facilitate the design of proposed and ongoing remediation work in and near the lake. The USGS study characterized the geology and geochemistry of the aquifer system, estimated the rate and direction of ground-water movement, and estimated mass loadings of chloride to Onondaga Lake and its tributaries from natural and anthropogenic sources. The study required analysis of existing hydrogeologic data and drilling of new test wells to collect additional hydrogeologic data to supplement this database. A three-dimensional geologic model of the unconsolidated deposits that fill the Onondaga Trough was developed from this information. Water-quality samples were collected, and hydraulic head (water-level) measurements were made in the test wells. The water samples were analyzed for a variety of chemical constituents to determine the composition and age of saline waters within the aquifer. The geologic model, together with the water-quality and hydraulic-head data, supported the development of several variable-density flow models of the aquifer system. The complete results of this study are summarized in Yager and others (2007a), which discusses the present location of the brine pool, potential sources of the brine, and the effects of the brine pool on ground-water flow near Onondaga Lake.

New York↗
USGS2011

Factors affecting groundwater quality in the Valley and Ridge aquifers, eastern United States, 1993-2002

Chemical and microbiological analyses of water from 230 wells and 35 springs in the Valley and Ridge Physiographic Province, sampled between 1993 and 2002, indicated that bedrock type (carbonate or siliciclastic rock) and land use were dominant factors influencing groundwater quality across a region extending from northwestern Georgia to New Jersey. The analyses included naturally occurring compounds (major mineral ions and radon) and anthropogenic contaminants [pesticides and volatile organic compounds (VOCs)], and contaminants, such as nitrate and bacteria, which commonly increase as a result of human activities. Natural factors, such as topographic position and the mineral composition of underlying geology, act to produce basic physical and geochemical conditions in groundwater that are reflected in physical properties, such as pH, temperature, specific conductance, and alkalinity, and in chemical concentrations of dissolved oxygen, radon, and major mineral ions. Anthropogenic contaminants were most commonly found in water from wells and springs in carbonate-rock aquifers. Nitrate concentrations exceeded U.S. Environmental Protection Agency maximum contaminant levels in 12 percent of samples, most of which were from carbonate-rock aquifers. Escherichia coli (E. coli), pesticide, and VOC detection frequencies were significantly higher in samples from sites in carbonate-rock aquifers. Naturally occurring elements, such as radon, iron, and manganese, were found in higher concentrations in siliciclastic-rock aquifers. Radon levels exceeded the proposed maximum contaminant level of 300 picocuries per liter in 74 percent of the samples, which were evenly distributed between carbonate- and siliciclastic-rock aquifers. The land use in areas surrounding wells and springs was another significant explanatory variable for the occurrence of anthropogenic compounds. Nitrate and pesticide concentrations were highest in samples collected from sites in agricultural areas and lowest in samples collected from sites in undeveloped areas. Volatile organic compounds were detected most frequently and in highest concentrations in samples from sites in urban areas, and least frequently in agricultural and undeveloped areas. No volatile organic compound concentrations and concentrations from only one pesticide, dieldrin, exceeded human-health benchmarks.

Alabama;Georgia;Tennessee;North Carolina;Virginia;↗
USGS1976

Basic data from five core holes in the Raft River geothermal area, Cassia County, Idaho

Studies of the geothermal aspect-of the Bridge area of the Raft River basin in south-central Idaho (fig. 1) by the U.S. Geological Survey began in 1972 when Young and Mitchell (1973) made a geochemical and geologic reconnaissance of selected thermal waters in Idaho. The Bridge area had been designated the Frazier known geothermal resource area (Frazier KGRA) by the U.S. Geological Survey (Godwin and others-, 1971) . Since 1972, several units of the Geological Survey have studied the area to provide data for the U.S. Energy Research and Development Administration, which proposes to ascertain whether the geothermal resource can be developed for power generation and other uses. The studies include geologic mapping, geophysical surveys, water sampling, test drilling, and studies of all available drill- hole data. A list of reports already prepared on the area is included with this report. Core drilling of five holes began in August 1974 and was completed in March 1975. These holes are referred to as intermediate-depth core holes, principally because in the spring of 1974, 35 auger holes 25 to 98 feet (7.6 to 30 meters) were completed in the area (Crosthwaite, 1974), and the Aerojet Nuclear Company, under the auspices of the U.S. Energy Research and Development Administration, was planning some deep drilling 4,000 to 6,000 feet (1,200 to 1,800 meters) (fig. 1). The purpose of the core drilling was to provide information to test geophysical interpretations of the subsurface structure and lithology and to provide hydrologic and geologic data on the shallow part of the geothermal system. Samples of the core were made available to several divisions and branches of the Geological Survey and to people and agencies outside the Survey. This report presents the basic data from the core holes that had been collected to September 1, 1975, and includes lithologic and geophysical well logs, chemical analyses of water (table 1), and laboratory analyses of cores (table 2) that were completed as of the above date. The data were collected by the Idaho District office, Hydrologic Laboratory, Borehole Geophysics Research Project, and Drilling, Sampling, and Testing Section, all of the Water Resources Division, and the Branch of Central Environmental Geology of the Geologic Divison.

Idaho↗
USGS2004

Global geologic context for rock types and surface alteration on Mars

Petrologic interpretations of thermal emission spectra from Mars orbiting spacecraft indicate the widespread occurrence of surfaces having basaltic and either andesitic or partly altered basalt compositions. Global concentration of ice-rich mantle deposits and near-surface ice at middle to high latitudes and their spatial correlation with andesitic or partly altered basalt materials favor the alteration hypothesis. We propose the formation of these units through limited chemical weathering from basalt interactions with icy mantles deposited during periods of high obliquity. Alteration of sediments in the northern lowlands depocenter may have been enhanced by temporary standing bodies of water and ice. ?? 2004 Geological Society of America.

Geology↗
USGS2011

Aeromagnetic anomalies over faulted strata

High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.). High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.).

The Leading Edge↗
USGS2008

Framework for Evaluating Water Quality of the New England Crystalline Rock Aquifers

Little information exists on regional ground-water-quality patterns for the New England crystalline rock aquifers (NECRA). A systematic approach to facilitate regional evaluation is needed for several reasons. First, the NECRA are vulnerable to anthropogenic and natural contaminants such as methyl tert-butyl ether (MTBE), arsenic, and radon gas. Second, the physical characteristics of the aquifers, termed 'intrinsic susceptibility', can lead to variable and degraded water quality. A framework approach for characterizing the aquifer region into areas of similar hydrogeology is described in this report and is based on hypothesized relevant physical features and chemical conditions (collectively termed 'variables') that affect regional patterns of ground-water quality. A framework for comparison of water quality across the NECRA consists of a group of spatial variables related to aquifer properties, hydrologic conditions, and contaminant sources. These spatial variables are grouped under four general categories (features) that can be mapped across the aquifers: (1) geologic, (2) hydrophysiographic, (3) land-use land-cover, and (4) geochemical. On a regional scale, these variables represent indicators of natural and anthropogenic sources of contaminants, as well as generalized physical and chemical characteristics of the aquifer system that influence ground-water chemistry and flow. These variables can be used in varying combinations (depending on the contaminant) to categorize the aquifer into areas of similar hydrogeologic characteristics to evaluate variation in regional water quality through statistical testing.

Open-File Report↗
USGS1930

Shorter contributions to general geology, 1929

Thin beds that consist almost wholly of euhedral analcite crystals occur at five or more horizons in the upper half of the Green River formation of Utah and Colorado, a series of Eocene lake beds that contain large deposits of oil shale. Most of these beds contain also minute crystals of apophyllite. The analcite crystals in some beds are cemented only by chalcedony, but in other beds that have less analcite the matrix is tuffaceous and consists of chalcedony in which are embedded splinters of feldspar, hornblende, and quartz, laths of biotite, and euhedral crystals of sanidine, apatite, and zircon. Analcite occurs plentifully also, disseminated in many of the oil-shale beds, and locally makes up as much as 16 per cent of weight of the rock. In these beds the analcite is accompanied by apophyllite, euhedral crystals of sanidine and orthoclase, angular fragments of quartz, and a little volcanic glass. The rocks associated with the beds of analcite and analcite-bearing oil shale contain salt-crystal cavities, that strongly suggest the former presence of glauberite and anhydrite. Both clastic and hydrothermal hypotheses for the origin of the zeolites are considered and dismissed in the paper. The field and microscopic evidence presented leads to the conclusion that all the analcite and apophyllite formed in place on the lake bottom as a result of interactions between salts dissolved in the lake water and the dissolution products of volcanic ash that fell into the lake. Meerschaum, or fibrous sepiolite, occurs in several thin beds near the top of the Green River formation in Duchesne County, Utah. It is mixed with structureless organic matter like that in the oil shale and apparently formed in place on the lake bottom. Chemical analyses of the analcite rock and of the sepiolite are given.

Professional Paper↗
USGS1947

Present investigations of radioactive raw materials by the Geological Survey and a recommended program for future work

The Geological Survey's program of investigation of radioactive raw materials is presented herewith under present investigations, plans for future investigations, plan of operation, and cost of operation. This report was prepared at the request of the Atomic Energy Commission. Present investigations are summarized to show the scope of the present Trace Elements program, grouping individual projects into related types of investigations. Plans for future investigations on an expanded scale are outlined. These should provide sufficient data and knowledge of the occurrence and availability of uranium, thorium, and related elements, to permit a more complete evaluation of domestic resources. Reconnaissance projects are designed to discover possible new sources of uranium and thorium and to select areas and materials warranting further investigation. Typical projects leading to the estimation of reserves are the investigation of the carnotite ores of the Colorado Plateau by geologic mapping, exploratory drilling, and related research, and investigation of asphaltic sandstone in Emery County, Utah. Extensive research will be undertaken to establish the principles governing the geological and geochemical relations of uranium, thorium, and associated elements as an essential guide in appraising domestic resources. Particular emphasis will be placed on phosphatic rocks and black shales which offer ultimate resources of uranium far greater than carnotite ores. All the foregoing investigations will be accompanied by chemical, gephysical, and mineralogical research and analytical work. Under plan of operation is discussed the organization of the Trace Elements Unit, space requirements for laboratory and office, the scheduling of investigations, and other related problems. The proposed scheduling of work calls for approximately 109, 173, and 203 man years in fiscal years 1948, 1949, and 1950 respectively. Definite plans have been formulated only for the next three fiscal years, by which time it is assumed the program will reach stable proportions or can be altered as experience dictates. Under cost of operation is set forth the funds available in fiscal year 1947, the status of funds transferred from Atomic Services (14-217/80920), and funds necessary in succeeding fiscal years. The estimate for fiscal year 1948 inclues a non-recurring item of $1,025,000 for establishing adequate laboratories for chemical, physical, spectrographic and mineralogic research and analytical work. The total funds required in fiscal years 1948, 1949, and 1950 to support the proposed program will be $2,440,000, $2,161,000 and $2,198,000 respectively. The Geological survey anticipates contributing from its appropriation in fiscal years 1948, 1949 and 1950 approximately $243,000, $350,000, and $400,000 respectively; the balance of the necessary funds to be contributed by the Atomic Energy Commission in fiscal years 1948, 1949, and 1950 will be approximately $2,196,900, $1,811,000, and $1,798,000 respectively.

Trace Elements Investigations↗
USGS1999

Vertical exchange of ground water and surface water in the Florida Everglades

Introduction and Project Objectives Knowledge about hydrologic exchange between surface water and ground water is critical to understanding the movement of water and dissolved chemical constituents (solutes) in the Florida Everglades. This fact sheet describes a study that will quantify vertical exchange of water and solutes in the Everglades as part of the U.S. Geological Survey's (USGS) South Florida Ecosystem Program. The two sites selected for the initial investigation are shown in the report. Those sites are the location of ongoing research projects concerned with movement and transformation of nutrients and mercury. Research results are being used by the South Florida Water Management District (SFWMD) to guide in the planning of Stormwater Treatment Areas, which will be large constructed wetlands designed to remove excess nutrients from agricultural drainage. The objectives of the project described here are to (1) quantify vertical exchange of water (also referred to as seepage) between ground water and surface water, (2) use seepage estimates to assist in the development of chemical mass balances for mercury and nutrients, and (3) relate seepage fluxes to subsurface hydrogeologic properties, management of surface-water levels in canals and water conservation areas, and the regional water balance in the northern Everglades.

Florida↗