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USGS1994

A summary of water-resources activities of the U.S. Geological Survey in Iowa, fiscal year 1994

Water-resources programs and activities of the U.S. Geological Survey in Iowa consist principally of hydrologic data collection and investigative studies that address water-resource issues. The work is supported by direct Federal funding, by transfer of funds from other Federal agencies, and by joint-funding agreements with State or local agencies. The Iowa District of the Geological Survey's Water Resources Division conducts its hydrologic work through a District Office in Iowa City and Field Headquarters in Iowa City, Council Bluffs, and Fort Dodge. The projects currently being conducted, as summarized in this report, are operated under the general categories of data collection and investigative studies. This report describes: (1) the organization of the Iowa District; (2) the hydrologic data-collection programs; and (3) the local, statewide, regional, or national hydrologic investigations conducted by the U.S. Geological Survey in Iowa during fiscal year 1994. The report also lists reports published or released by the Iowa District since 1984.

Iowa↗
USGS2014

Seepage investigation on the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, 2012

A seepage investigation was conducted by the U.S. Geological Survey, in cooperation with the New Mexico Interstate Stream Commission, along an approximately 106-mile reach of the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, during June 26–28, 2012, to determine gain or loss of streamflow due to seepage to or from the river channel. Discharge measurements were made during the irrigation season at high flow including 5 sites along the Rio Grande, 5 diversions, and 63 inflows. The net gain or loss of flow in the river channel was computed for four reaches within the 106-mile reach of the Rio Grande. The normalized percentage difference was computed for each reach to determine the difference between discharge measured at upstream and downstream sites, and the normalized percentage uncertainty was computed to determine if a computed gain or loss exceeded cumulative uncertainty associated with measurement of discharge.

New Mexico, Texas↗
USGS2016

Aeromagnetic map of northwest Utah and adjacent parts of Nevada and Idaho

Two aeromagnetic surveys were flown to promote further understanding of the geology and structure in northwest Utah and adjacent parts of Nevada and Idaho by serving as a basis for geophysical interpretations and by supporting geological mapping, water and mineral resource investigations, and other topical studies. Although this area is in general sparsely populated, (except for cities and towns along the Wasatch Front such as Ogden and Brigham City), it encompasses metamorphic core complexes in the Grouse Creek and Raft River Mountains (figure 1) of interest to earth scientists studying Cenozoic extension. The region was shaken in 1909 and 1934 by M6+ earthquakes east of the Hansel Mountains (Doser, 1989; Arabasz and others, 1994); damage from the 1934 earthquake occurred as far east as Logan, Utah (http:// www.seis.utah.edu/lqthreat/nehrp_htm/1934hans/n1934ha1. shtml#urbse). The presence of Quaternary shield volcanoes and bimodal Pleistocene volcanism in Curlew Valley (Miller and others, 1995; Felger and others, 2016) as well as relatively high temperature gradients encountered in the Indian Cove drillhole in the north arm of Great Salt Lake (Blackett and others, 2014) may indicate some potential for geothermal energy development in the area (Miller and others, 1995). The area also hosts four significant mining districts, in the northern Pilot Range, the Goose Creek Mountains in the northwest corner of the map, the southern end of the Promontory Mountains, and the southwest part of the Raft River Mountains, although production notably waned after World War II (Doelling, 1980). Other prospects of interest include those in the southern Grouse Creek Mountains, Silver Island, and the northern Newfoundland Mountains. Large areas of northwest Utah are covered by young, surficial deposits or by Great Salt Lake or are down-dropped into deep Cenozoic basins, making extrapolation of bedrock geology from widely spaced exposures difficult or tenuous (figure 1). Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals commonly mark lithologic or structural boundaries. Magnetic data reflect magnetization variations within the crust and are well suited for mapping the distribution of mafic igneous rocks, although felsic igneous rocks, some mineralized zones, and other rock types also can produce measurable magnetic anomalies. For these reasons, the U.S. Geological Survey (USGS) and Utah Geological Survey (UGS) contracted for the collection of aeromagnetic data in this area.

Idaho, Nevada, Utah↗
USGS2014

Investigations into near-real-time surveying for geophysical data collection using an autonomous ground vehicle

The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.

California↗
USGS1988

Water-resources activities of the U.S. Geological Survey in Missouri, fiscal year 1987

Water resources activities of the U.S. Geological Survey in Missouri consist of collecting hydrologic data and making interpretive studies. Hydrologic studies in Missouri are made through three basic types of projects: (1) hydrologic data-collection program, (2) local or areal hydrologic investigations, and (3) statewide or regional studies. These projects are funded through cooperative joint-funding agreements with State and local agencies, transfer of funds from other Federal agencies, and direct Federal funds. The data and the results of the investigations are published or released by either the U.S. Geological collection programs and local or areal hydrologic investigations in Missouri for fiscal year 1987 and provides a list of selected water-resources references for Missouri. (USGS)

Open-File Report↗
USGS1960

Geology, water resources and usable ground-water storage capacity of part of Solano County, California

The area described is confined largely to the valley-floor and foothill lands of Solano County, which lies directly between Sacramento, the State capital, and San Francisco. The area is considered in two subareas: The Putah area, which extends from Putah Creek southward to the Montezuma Hills and from the foothills of the Coast Ranges eastward to the west edge of the Yolo Bypass; and the Suisun-Fairfield area, which is to the southwest in the notch in the Coast Ranges through which the waters of the Great Central Valley of California reach San Francisco Bay. There are no known hydrologic interconnections between the two subareas, through either surface streams or underground aquifers. The climate of the area is characterized by warm, rainless summers and by cool winters in which temperatures seldom drop much below freezing. The rainfall ranges from about 17 inches per year along the east side to perhaps 24 inches in the foothills to the west, and irrigation is necessary for all crops except dry-farmed grains, pastures, and some orchards. PUTAH AREA The Putah area occupies the southwestern corner of the Sacramento Valley, a topographic and structural basin underlain by a thick accumulation of sediments eroded from the surrounding hills and mountains by the Sacramento River and its tributaries. The eastern Coast Ranges and foothills lying west of the Sacramento Valley are a generally northward-trending belt of eastward-dipping sedimentary rocks that range in age from Cretaceous to Pleistocene. Successively younger strata are exposed eastward, and the essentially undeformed deposits of late Pleistocene and Recent age that immediately underlie the valley lap onto the tilted sediments of the foothills. Most of the streams of the Putah area rise east of the high ridge of Cretaceous rocks marking the western boundaries of Solano and Yolo Counties, but Putah Creek, the largest stream in the area, rises far west of that ridge and flows across it in a deep, narrow canyon. Putah Creek and the smaller streams have constructed an alluvial plain, herein designated the Putah plain, which slopes eastward and southeastward from the foothills toward the Sacramento River. A large part of the Putah plain is traversed by a branching set of distributary channel ridges or natural levees formed at times of overflow of Putah Creek. The rocks in the Putah area range in age from Cretaceous to Recent. For the purposes of this investigation they are divided into eight geologic or stratigraphic units, from youngest to oldest: (1) Stream-channel deposits, (2) younger alluvium, (3) older alluvium, (4) Tehama formation and related continental sediments, (5) volcanic sedimentary rocks, (6) basalt, (7) undifferentiated sedimentary rocks of Paleocene(?) and Eocene age, and (8) undifferentiated rocks of Cretaceous age. The stream-channel deposits are predominantly loose sand and gravel along the channel of Putah Creek. In part they are actively moving downstream and shifting. The younger alluvium, of Recent age, consists of flood-plain deposits underlying the Putah plain, Vaca Valley, Pleasants Valley, and the small valleys in the foothills north of Putah Creek and in the English Hills. Exposures of younger alluvium are characterized by soils lacking significant profile development and in many places by channel-ridge topography. The older alluvium occupies the stratigraphic interval between the younger alluvium and the Tehama formation and related continental sediments and is probably of late Pleistocene age. Its contact with the underlying Tehama formation and related continental sediments is unconformable near the foothills, but it may be gradational beneath much of the Putah plain. The base of the older alluvium is not well defined at many places but is inferred to be at the bottom of an irregular and ill-defined zone of coarse deposits, which ranges from about 50 feet to more than 150 feet below the land surface. Exposures of the older

Water Supply Paper↗
USGS2020

Geologic map of the Dog River and northern part of the Badger Lake 7.5′ quadrangles, Hood River County, Oregon

The Dog River and northern part of the Badger Lake 7.5' quadrangles encompasses an area of ~201 km2 (77.6 mi2) of the High Cascades of north-central Oregon, lying across the eastern slopes of Mount Hood volcano (Figure 1-1; Plate 1; referred to herein as Dog River–Badger Lake area). Mount Hood, known as Wy’east to Native Americans, is Oregon’s tallest peak (3,427 m [11,241 ft]). The volcano has erupted episodically for the past 500,000 years, experiencing two major eruptive periods during the last 1,500 years (Scott and others, 1997a; Scott and others, 2003; Scott and Gardner, 2017). Cascade Range volcanism and structural development in the area dates back longer, with eruptive activity dating from latest Miocene to recent time; part of that volcano-tectonic record is detailed by new high-resolution geologic mapping presented here. The geology of the Dog River–Badger Lake area was mapped by the Oregon Department of Geology and Mineral Industries (DOGAMI) between 2017 and 2020, in collaboration with geoscientists from the U. S. Geological Survey Cascade Volcano Observatory (USGS CVO) and Hamilton College, New York. The primary objective of this investigation is to provide an updated and spatially accurate geologic framework for the Dog River–Badger Lake area as part of a multi-year study of the geology of the larger Middle Columbia Basin (Figure 1-1, Figure 1-2). Additional key objectives of this project are to: 1) determine the geologic history of volcanic rocks in this part of the northern Oregon Cascade Range, including lava flows and volcaniclastic deposits erupted from Middle Pleistocene to Holocene Mount Hood volcano; 2) provide significant new details about the structure and fault history along the northern segment of the High Cascades intra-arc graben (Hood River graben); and 3) better understand geologic hazards in the region, related to earthquakes, volcanoes, and landslides. New detailed geologic data presented here also provides a basis for future geologic, geohydrologic, and geohazard studies in the greater Middle Columbia Basin. Detailed geologic mapping in this part of the Middle Columbia Basin is a high priority of the Oregon Geologic Map Advisory Committee (OGMAC), supported in part by grants from the STATEMAP component of the USGS National Cooperative Geologic Mapping Program (G17AC00210, G19AC00160). Additional funds were provided by the State of Oregon. The core products of this study are this report, an accompanying geologic map and cross sections (Plate 1), an Esri ArcGIS™ geodatabase, and Microsoft Excel® spreadsheets tabulating point data for geochemistry, geochronology, magnetic polarity, orientation points, and well data. The geodatabase presents the new geologic mapping in a digital format consistent with the USGS National Cooperative Geologic Mapping Program Geologic Map Schema (GeMS) (U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020). This geodatabase contains spatial information, including geologic polygons, contacts, structures, geochemistry, geochronology, magnetic observation, orientation points, and well data, as well as data about each geologic unit such as age, lithology, mineralogy, and structure. Digitization at scales of 1:8,000 or better was accomplished using a combination of high-resolution lidar topography and imagery. Surficial and bedrock geologic units contained in the geodatabase are depicted on the Plate 1 at a scale of 1:24,000. Both the geodatabase and geologic map are supported by this report describing the geology in detail.

Oregon↗
USGS1999

Mining geology of the Pond Creek seam, Pikeville Formation, Middle Pennsylvanian, in part of the Eastern Kentucky Coal Field, USA

The Pond Creek seam is one of the leading producers of coal in the Eastern Kentucky Coal Field. The geologic factors that affect mining were investigated in several underground mines and categorized in terms of coal thickness, coal quality, and roof control. The limits of mining and thick coal are defined by splitting along the margin of the coal body. Within the coal body, local thickness variation occurs because of (1) leader coal benches filling narrow, elongated depressions, (2) rider coal benches coming near to or merging with the main bench, (3) overthrust coal benches being included along paleochannel margins, (4) cutouts occuring beneath paleochannels, and (5) very hard and unusual rock partings occuring along narrow, elongated trends. In the study area, the coal is mostly mined as a compliance product: sulfur contents are less than 1% and ash yields are less than 10%. Local increases in sulfur occur beneath sandstones, and are inferred to represent post-depositional migration of fluids through porous sands into the coal. Run-of-mine quality is also affected by several mine-roof conditions and trends of densely concentrated rock partings, which lead to increased in- and out-of-seam dilution and overall ash content of the mined coal. Roof control is largely a function of a heterolithic facies mosaic of coastal-estuarine origin, regional fracture trends, and unloading stress related to varying mine depth beneath the surface. Lateral variability of roof facies is the rule in most mines. The largest falls occur beneath modern valleys and parallel fractures, along paleochannel margins, within tidally affected 'stackrock,' and beneath rider coals. Shale spalling, kettlebottoms, and falls within other more isolated facies also occur. Many of the lithofacies, and falls related to bedding weaknesses within or between lithofacies, occur along northeast-southwest trends, which can be projected in advance of mining. Fracture-related falls occur independently of lithofacies trends along northwest-southeast trends, especially beneath modern valleys where overburden thickness decreases sharply. Differentiating roof falls related to these trends can aid in predicting roof quality in advance of mining.The Pond Creek-Lower Elkhorn seam has been an important exploration target because it typically has very low sulfur contents and ash yields. Geologic research in several large Pond Creek mines suggested variability in roof quality and coal thickness. Due to mine access, geologic problems encountered during mining are documented and described.

International Journal of Coal Geology↗
USGS2012

Review and update of the applications of organic petrology: Part 2, geological and multidisciplinary applications

The present paper is focused on organic petrology applied to unconventional and multidisciplinary investigations and is the second part of a two part review that describes the geological applications and uses of this branch of earth sciences. Therefore, this paper reviews the use of organic petrology in investigations of: (i) ore genesis when organic matter occurs associated with mineralization; (ii) the behavior of organic matter in coal fires (self-heating and self-combustion); (iii) environmental and anthropogenic impacts associated with the management and industrial utilization of coal; (iv) archeology and the nature and geographical provenance of objects of organic nature such as jet, amber, other artifacts and coal from archeological sites; and (v) forensic science connected with criminal behavior or disasters. This second part of the review outlines the most recent research and applications of organic petrology in those fields.

International Journal of Coal Geology↗
USGS2017

Field-trip guides to selected volcanoes and volcanic landscapes of the western United States

The North American Cordillera is home to a greater diversity of volcanic provinces than any comparably sized region in the world. The interplay between changing plate-margin interactions, tectonic complexity, intra-crustal magma differentiation, and mantle melting have resulted in a wealth of volcanic landscapes. Field trips in this guide book collection (published as USGS Scientific Investigations Report 2017–5022) visit many of these landscapes, including (1) active subduction-related arc volcanoes in the Cascade Range; (2) flood basalts of the Columbia Plateau; (3) bimodal volcanism of the Snake River Plain-Yellowstone volcanic system; (4) some of the world’s largest known ignimbrites from southern Utah, central Colorado, and northern Nevada; (5) extension-related volcanism in the Rio Grande Rift and Basin and Range Province; and (6) the eastern Sierra Nevada featuring Long Valley Caldera and the iconic Bishop Tuff. Some of the field trips focus on volcanic eruptive and emplacement processes, calling attention to the fact that the western United States provides opportunities to examine a wide range of volcanological phenomena at many scales. The 2017 Scientific Assembly of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) in Portland, Oregon, was the impetus to update field guides for many of the volcanoes in the Cascades Arc, as well as publish new guides for numerous volcanic provinces and features of the North American Cordillera. This collection of guidebooks summarizes decades of advances in understanding of magmatic and tectonic processes of volcanic western North America. These field guides are intended for future generations of scientists and the general public as introductions to these fascinating areas; the hope is that the general public will be enticed toward further exploration and that scientists will pursue further field-based research.

Scientific Investigations Report↗
USGS2022

Hydrogeology of aquifers within the Fairport-Lyons channel system and adjacent areas in Wayne, Ontario, and Seneca Counties, New York

A hydrogeologic investigation was undertaken by the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, within the areas shown in the Macedon, Palmyra, Newark, and Lyons 7.5-minute quadrangle maps that include parts of Wayne, Ontario, and Seneca Counties in New York. The most productive zone of aquifers within the study area is associated with the Fairport-Lyons glacial-stream channel (hereinafter referred to as the “Fairport-Lyons channel”) in southern Wayne County and adjacent areas. The Fairport-Lyons channel is a west-east-oriented bedrock channel that once served as the outlet for glacial Lake Dawson, which occupied the Genesee Valley near Rochester during the Pleistocene. The Fairport-Lyons channel and intersecting subsidiary channels are hereinafter referred to as the “Fairport-Lyons channel system.” Glacial meltwater eroded this shallow channel network into the underlying bedrock, and the channels subsequently filled with interlayered glaciofluvial sand and gravel and fine-grained lacustrine deposits. These sand and gravel deposits provide the only large supplies of groundwater in Wayne County under unconfined and confined conditions and serve a population of over 20,000 through a combination of domestic and municipal water supply wells. The largest reported well yield, 1,200 gallons per minute, is from an industrial supply well near Newark, N.Y. Much of the sand and gravel within the Fairport-Lyons channel system is generally thinly saturated; however, in three areas—near Macedon, Newark, and Lyons, N.Y.—the saturated thickness of the aquifer is sufficient to support groundwater yields adequate for municipal and industrial use, in part because of induced infiltration from the Erie Canal.

New York↗
USGS1996

Instream investigations in the Beaver Creek Watershed in West Tennessee, 1991-95

The U.S. Geological Survey (USGS), in cooperation with the Tennessee Department of Agriculture, began a long-term scientific investigation in 1989 to evaluate the effect of agricultural activities on water quality and the effectiveness of agricultural best management practices in the Beaver Creek watershed, West Tennessee. In 1993 as a part of this study, the USGS, in cooperation with the Natural Resources Conservation Service, Shelby County Soil Conservation District, and the Tennessee Soybean Promotion Board, began an evaluation of the physical, chemical, biological and hydrological factors that affect water quality in streams and wetlands, and instream resource-management systems to treat agricultural nonpoint-source runoff and improve water quality. The purpose of this report is to present the results of three studies of stream and wetland investigations and a study on the transport of aldicarb from an agricultural field in the Beaver Creek watershed. A natural bottomland hardwood wetland and an artificially constructed wetland were evaluated as instream resource-management systems. These two studies showed that wetlands are an effective way to improve the quality of agricultural nonpoint-source runoff. The wetlands reduced concentrations and loads of suspended sediments, nutrients, and pesticides in the streams. A third paper documents the influence of riparian vegetation on the biological structure and water quality of a small stream draining an agricultural field. A comparison of the upper reach lined with herbaceous plants and the lower reach with mature woody vegetation showed a more stable biological community structure and Water- quality characteristics in the woody reach than in the herbaceous reach. The water-quality characteristics monitored were pH, temperature, dissolved oxygen, and specific conductance. The herbaceous reach had a greater diversity and abundance of organisms during spring and early summer, but the abundance dropped by approximately 85 percent during late summer. A fourth study describes the transport of aldicarb and its metabolites--aldicarb sulfoxide and aldicarb sulfone-in runoff at a small stream draining a cotton field. During 1991 to 1995, aldicarb and its metabolites were detected in runoff events. The highest concentrations occurred when aldicarb was applied to the field just hours before a rain storm. Aldicarb was not detectable in runoff a few weeks after application. The metabolites of aldicarb were detectable for 76 days after application. These studies demonstrate streambank vegetation and wetlands have a significant influence on stream water quality. The importance of weather conditions to herbicide application and runoff also is evident. This information can be used by resource managers to sustain and improve our Nation's streams for future generations.

Water-Resources Investigations Report↗
USGS1993

Hydrogeology and water quality of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1991-92

The purpose of this letter is to describe the results of the final phase (phase 3) of the U.S. Geological Survey's (USGS) ground-water investigation at the Parson's Casket Hardware site, Belvidere, Ill. (figs. 1 and 2), for the U.S. Environmental Protection Agency (USEPA). Included in this letter are brief descriptions of (1) study methods employed in the phase 3 investigation that have not been previously described in earlier reports, and (2) results of the phase 3 investigation as they relate to the results of the previous phases of the investigation. The data from the phase 3 investigation that are presented and described herein were collected during November 1991-January 1992. The Galena-Platteville aquifer is the uppermost bedrock aquifer beneath the site. The Glenwood Formation of Ordovician age, a potential confining unit, separates the Galena-Platteville aquifer from the underlying St. Peter Sandstone aquifer (fig. 3). The St. Peter Sandstone aquifer is an important source of ground water to Belvidere and other cities in the region. The phase 3 investigation was done (1) to determine the lithology of the Glenwood Formation; (2) to determine the vertical distribution of horizontal hydraulic conductivity (K) and concentrations of volatile organic compounds (VOC's) in the upper 150 ft (feet) of the Galena-Platteville aquifer at an existing monitoring location, borehole G127GP (figs. 2 and 3) ; and (3) to confirm the presence or absence of VOC's in the St. Peter Sandstone aquifer at a new monitoring location, well G127SP (figs. 2 and 3). Additional components of the site investigation described in this letter include determination of vertical hydraulic gradients between the Galena-Platteville and St. Peter Sandstone aquifers and in situ measurement of selected water-quality characteristics (pH, temperature, specific conductance, Eh, and dissolved oxygen) in borehole G127GP. The results of the first and second phases of the USGS investigation at the Parson's Casket Hardware site are presented in two previous USGS Open-File Reports prepared for the USEPA (Mills, 1993a, 1993b) . These reports describe the hydrogeology of the study site, principally the Galena-Platteville aquifer, and the distribution of VOC concentrations in the Galena-Platteville aquifer. (The stratigraphic nomenclature used in this report is that of the Illinois State Geological Survey (Willman and others, 1975, p. 47-87) and does not necessarily follow the usage of the USGS. The aquifer nomenclature is that generally used by the Illinois State Geological Survey and the U.S. Environmental Protection Agency.) The previous two reports also describe most of the study methods employed in the phase 3 investigation.

Open-File Report↗
USGS2002

Environmental setting and water-quality issues of the Mobile River Basin, Alabama, Georgia, Mississippi, and Tennessee

The Mobile River Basin is one of over 50 river basins and aquifer systems being investigated as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. This basin is the sixth largest river basin in the United States, and fourth largest in terms of streamflow, encompassing parts of Alabama, Georgia, Mississippi, and Tennessee. Almost two-thirds of the 44,000-square-mile basin is located in Alabama. Extensive water resources of the Mobile River Basin are influenced by an array of natural and cultural factors. These factors impart unique and variable qualities to the streams, rivers, and aquifers providing abundant habitat to sustain the diverse aquatic life in the basin. Data from Federal, State, and local agencies provide a description of the environmental setting of the Mobile River Basin. Environmental data include natural factors such as physiography, geology, soils, climate, hydrology, ecoregions, and aquatic ecology, and human factors such as reservoirs, land use and population change, water use, and water-quality issues. Characterization of the environmental setting is useful for understanding the physical, chemical, and biological characteristics of surface and ground water in the Mobile River Basin and the possible implications of that environmental setting for water quality. The Mobile River Basin encompasses parts of five physiographic provinces. Fifty-six percent of the basin lies within the East Gulf section of the Coastal Plain Physiographic Province. The remaining northeastern part of the basin lies, from west to east, within the Cumberland Plateau section of the Appalachian Plateaus Physiographic Province, the Valley and Ridge Physiographic Province, the Piedmont Physiographic Province, and the Blue Ridge Physiographic Province. Based on the 1991 land-use data, about 70 percent of the basin is forested, while agriculture, including livestock (poultry, cattle, and swine), row crops (cotton, corn, soybeans, sorghum, and wheat), and pasture land accounts for about 26 percent of the study unit. Agricultural land use is concentrated along the Black Prairie Belt district of the Coastal Plain. Urban areas account for only 3 percent of the total land use; however, the areal extent of the metropolitan statistical areas (MSA) may indicate more urban influences. The MSAs include urban areas outside of the city boundaries and can include adjacent counties. Seven MSAs are delineated in the Mobile River Basin, including Montgomery, Mobile, Tuscaloosa, Birmingham, Gadsden, Anniston, and Atlanta. The total population for the Mobile River Basin was about 3,673,100 in 1990. State water-quality agencies have identified numerous causes and sources of water-body impairment in the Mobile River Basin. In 1996, organic enrichment, dissolved oxygen depletion, elevated nutrient concentrations, and siltation were the most frequently cited causes of impairment, affecting the greatest number of river miles. Bacteria, acidic pH, and elevated metal concentrations also were identified as causes of impairment. The sources for impairment varied among river basins, were largely a function of land use, and were attributed primarily to municipal and industrial sources, mining, and agricultural activities.

Water-Resources Investigations Report↗
USGS1995

Hydrogeology, ground-water quality, and source of ground water causing water-quality changes in the Davis well field at Memphis, Tennessee

An investigation was conducted by the U.S. Geological Survey from 1992 to 1994 to collect and interpret hydrogeologic and water-quality data to determine the source of ground water causing water-quality changes in water from wells screened in the Memphis aquifer in the Davis well field at Memphis, Tennessee. Water-quality changes in aquifers used for water supply are of concern because these changes can indicate a potential for contamination of the aquifers by downward leakage from near-surface sources. The water-quality changes at the Davis well field were detected by Memphis Light, Gas and Water Division, which has periodically sampled and analyzed water from many of the 14 production wells since the well field began operation in 1971. Memphis Light, Gas and Water Division analyzed the water samples primarily for hardness, alkalinity, chloride, ulfate, and iron. Results of the e analy es and results of more recent (1992) analyse of water samples by the U.S. Geological Survey indicate that the quality of water from eight of the production wells has changed since the well field began operation. For example, from 1972 to 1991, hardness of water from one well has increased from 90 to 292 milligrams per liter (224 percent). The confining unit, which separates the fluvial deposits aquifer from the Memphis aquifer in the area of the well field, is relatively thick and contains many clay layers. However, a test hole drilled for one of five shallow wells installed in the alluvial aquifer in the Mississippi Alluvial Plain just west of the well field indicated that the confining unit separating the alluvial aquifer from the Memphis aquifer locally is absent. Differences in hydrauLic head between the alluvial and fluvial deposits aquifers and the Memphis aquifer favor downward leakage of ground water. Thus, the absence of the confining unit beneath the Mississippi Alluvial Plain just west of the well field provides a direct pathway for water in the alluvial aquifer to enter the Memphis aquifer. Comparison of selected water-quality properties and major inorganic and trace element constituent concentrations in samples from the alluvial, fluvial deposits, and Memphis aquifers indicates that the source of ground water causing waterquality changes at the Davis well field is the alluvial aquifer west of the well field . The presence of tritium and chlorofluorocarbons in water from wells screened in the Memphis aquifer in the western part of the well field indicates that relatively young (post-1940) water from the alluvial aquifer has entered the Memphis aquifer. NETPATH geochemical model code was used to mix waters from the alluvial aquifer with water from the Memphis aquifer using chloride as a conservative tracer. The resulting models indicated that a mixture containing 3 percent alluvial aquifer water mixed with 97 percent unaffected Memphis aquifer water would produce the chloride concentration measured in water from the Memphis aquifer well most affected by water-quality changes. NETPATH also was used to calculate mixing percentages of alluvial and Memphis aquifer Abstract waters based on changes in the concentrations of selected dissolved major inorganic and trace element constituents that define the dominant reactions that occur during mixing. These models indicated that a mixture containing 18 percent alluvial aquifer water and 82 percent unaffected Memphis aquifer water would produce the major constituent and trace element concentrations measured in water from the Memphis aquifer well most affected by water-quality changes. However, these model simulations predicted higher dissolved methane concentrations than were measured in water samples from the Memphis aquifer wells.

Tennessee↗
USGS2006

Statewide analysis of the drainage-area ratio method for 34 streamflow percentile ranges in Texas

The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data are available using data from one or more nearby streamflow-gaging stations. The method is intuitive and straightforward to implement and is in widespread use by analysts and managers of surface-water resources. The method equates the ratio of streamflow at two stream locations to the ratio of the respective drainage areas. In practice, unity often is assumed as the exponent on the drainage-area ratio, and unity also is assumed as a multiplicative bias correction. These two assumptions are evaluated in this investigation through statewide analysis of daily mean streamflow in Texas. The investigation was made by the U.S. Geological Survey in cooperation with the Texas Commission on Environmental Quality. More than 7.8 million values of daily mean streamflow for 712 U.S. Geological Survey streamflow-gaging stations in Texas were analyzed. To account for the influence of streamflow probability on the drainage-area ratio method, 34 percentile ranges were considered. The 34 ranges are the 4 quartiles (0-25, 25-50, 50-75, and 75-100 percent), the 5 intervals of the lower tail of the streamflow distribution (0-1, 1-2, 2-3, 3-4, and 4-5 percent), the 20 quintiles of the 4 quartiles (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95, and 95-100 percent), and the 5 intervals of the upper tail of the streamflow distribution (95-96, 96-97, 97-98, 98-99 and 99-100 percent). For each of the 253,116 (712X711/2) unique pairings of stations and for each of the 34 percentile ranges, the concurrent daily mean streamflow values available for the two stations provided for station-pair application of the drainage-area ratio method. For each station pair, specific statistical summarization (median, mean, and standard deviation) of both the exponent and bias-correction components of the drainage-area ratio method were computed. Statewide statistics (median, mean, and standard deviation) of the station-pair specific statistics subsequently were computed and are tabulated herein. A separate analysis considered conditioning station pairs to those stations within 100 miles of each other and with the absolute value of the logarithm (base-10) of the ratio of the drainage areas greater than or equal to 0.25. Statewide statistics of the conditional station-pair specific statistics were computed and are tabulated. The conditional analysis is preferable because of the anticipation that small separation distances reflect similar hydrologic conditions and the observation of large variation in exponent estimates for similar-sized drainage areas. The conditional analysis determined that the exponent is about 0.89 for streamflow percentiles from 0 to about 50 percent, is about 0.92 for percentiles from about 50 to about 65 percent, and is about 0.93 for percentiles from about 65 to about 85 percent. The exponent decreases rapidly to about 0.70 for percentiles nearing 100 percent. The computation of the bias-correction factor is sensitive to the range analysis interval (range of streamflow percentile); however, evidence suggests that in practice the drainage-area method can be considered unbiased. Finally, for general application, suggested values of the exponent are tabulated for 54 percentiles of daily mean streamflow in Texas; when these values are used, the bias correction is unity.

Scientific Investigations Report↗
USGS2003

Occurrence and distribution of nutrients, suspended sediment, and pesticides in the Mobile River Basin, Alabama, Georgia, Mississippi, and Tennessee, 1999-2001

The Mobile River Basin is one of more than 50 river basins and aquifer systems being investigated as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. This basin is the sixth largest river basin in the United States and the fourth largest in terms of streamflow. The Mobile River Basin encompasses parts of Alabama, Georgia, Mississippi, and Tennessee, and almost two-thirds of the 44,0000-square-mile basin is located in Alabama. The extensive water resources of the Mobile River Basin are influenced by an array of natural and cultural factors, which impart unique and variable qualities to the streams, rivers, and aquifers and provide abundant habitat to sustain the diverse aquatic life in the basin. From January 1999 to December 2001, a study was conducted of the occurrence and distribution of nutrients, suspended sediment, and pesticides in surface water of the Mobile River Basin. Nine sampling sites were selected on the basis of land use. The nine sites included two streams draining agricultural areas, two urban streams, and five large rivers with mixed land use. Surface-water samples were collected from one to four times each month to characterize the spatial and temporal variation in nutrient and pesticide concentrations. Nutrient and suspended-sediment concentrations were highest in watersheds dominated by urban or agricultural land uses. Forty-two percent of the total phosphorus concentrations at all nine sites exceeded the U.S. Environmental Protection Agency's recommended maximum concentration of 0.1 milligram per liter. Flow-weighted mean concentrations at the Mobile River Basin sites generally were in the lower to middle percentile ranges compared with data from other NAWQA studies across the Nation. However, flow-weighted mean concentrations of ammonia, total nitrogen, orthophosphate, and total phosphorus at Bogue Chitto Creek, an agricultural watershed, ranked in the upper 20th percentile of agricultural sites sampled across the Nation as part of the NAWQA Program. Nutrient loads in the Tombigbee River were nearly twice as high compared with nutrient loads in the Alabama River. Nutrient yields were highest in Bogue Chitto Creek, Cahaba Valley Creek, and Threemile Branch because of agricultural and urban land uses in these watersheds. Of the 104 pesticides and degradation products analyzed in the stream samples, 69 were detected in one or more samples. Of the 69 detected pesticides, 51 were herbicides, 15 were insecticides, and 3 were fungicides. A relatively small number of heavily used herbicides accounted for most of the detections, including atrazine and its metabolites (deethylatrazine, 2-hydroxyatrazine, deisopropylatrazine, and deethyldeisopropylatrazine), simazine, metolachlor, tebuthiuron, prometon, diuron, and 2,4-D. Diazinon, chlorpyrifos, and carbaryl were the most frequently detected insecticides; metalaxyl was the most frequently detected fungicide in the Mobile River Basin. Concentrations of pesticides detected in surface water of the Mobile River Basin were among the highest concentrations recorded nationally by the NAWQA Program during 1991 to 2001. The three highest concentrations of atrazine detected at sites across the country were recorded at Bogue Chitto Creek; the highest concentrations of 2,4-D, imazaquin, and malathion recorded nationally were detected at Threemile Branch. Aquatic-life criteria were exceeded by concentrations of five herbicides (2,4-D, atrazine, cyanazine, diuron, and metolachlor), six insecticides (carbaryl, chlorpyrifos, diazinon, dieldrin, malathion, and p,p'-DDE), and one fungicide (chlorothalonil). Drinking-water standards were exceeded by concentrations of four herbicides (2,4-D, atrazine, cyanazine, and simazine), three insecticides (alpha- HCH, diazinon, and dieldrin), and one fungicide (chlorothalonil). The types and concentrations of pesticides found in surface water are linked to land use and to the types of pesti

Alabama, Georgia, Mississippi, Tennessee↗
USGS1996

Sources and loads of nutrients in the South Platte River, Colorado and Nebraska, 1994-95

The South Platte River Basin was one of 20 river basins selected in 1991 for investigation as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. Nationwide, nutrients have been identified as one of the primary nationwide water-quality concerns and are of particular interest in the South Platte River Basin where nutrient concentrations are large compared to concentrations in other NAWQA river basins. This report presents estimates of the magnitude of nutrient-source inputs to the South Platte River Basin, describes nutrient concen- trations and loads in the South Platte River during different seasons, and presents comparisons of nutrient inputs to instream nutrient loads. Annual nutrient inputs to the basin were estimated to be 306,000 tons of nitrogen and 41,000 tons of phosphorus. The principal nutrient sources were wastewater-treatment plants, fertilizer and manure applications, and atmospheric deposition. To characterize nutrient concentrations and loads in the South Platte River during different seasons, five nutrient synoptic samplings were conducted during 1994 and 1995. Upstream from Denver, Colorado, during April 1994 and January 1995, total nitrogen concentrations were less than 2 milligrams per liter (mg/L), and total phosphorus concentrations were less than 0.2 mg/L. The water in the river at this point was derived mostly from forested land in the mountains west of Denver. Total nutrient concentrations increased through the Denver metropolitan area, and concentration peaks occurred just downstream from each of Denver's largest wastewater-treatment plants with maximum concentrations of 13.6 mg/L total nitrogen and 2.4 mg/L total phosphorus. Nutrient concen- concentrations generally decreased downstream from Denver. Upstream from Denver during April 1994 and January 1995, total nitrogen loads were less than 1,000 pounds per day (lb/d), and total phosphorus loads were less than 125 lb/d. Total nutrient loads increased through the Denver metropolitan area, and load peaks occurred just downstream from each of Denver's largest wastewater-treatment plants, with a maximum load of 14,000 lb/d total nitrogen and 2,300 lb/d total phosphorus. In April 1994, nutrient loads generally decreased from Henderson, Colorado, to North Platte, Nebraska. In January 1995, however, nutrient loads increased from Henderson to Kersey, Colorado (maximum loads of 31,000 lb/d total nitrogen and 3,000 lb/d total phosphorus), and then decreased from Kersey to North Platte. Seasonal nutrient loads primarily were dependent on streamflow. Total nitrogen loads were largest in June 1994 and January 1995 when streamflows also were largest. During June, streamflow was large, but nitrogen concentrations were small, which indicated that snowmelt runoff diluted the available supply of nitrogen. Total phosphorus loads were largest in June, when streamflow and phosphorus concentrations were large, which indicated an additional source of phosphorus during snowmelt runoff. Streamflow along the South Platte River was smallest in April and August 1994, and nutrient loads also were smallest during these months. The downstream pattern for nutrient loads did not vary much by season. Loads were large at Henderson, decreased between Henderson and Kersey, and usually were largest at Kersey. The magnitude of the decrease in loads between Henderson and Kersey varied between synoptics and was dependent on the amount of water removed by irrigation ditches. Nutrient loads leaving the basin were very small compared to the estimated total nutrient inputs to the basin. Streamflow balances indicated that the South Platte River is a gaining river throughout much of its length; streamflow-balance residuals were as large as 15 cubic feet per second per mile. Nutrient-load balances indicated that increases in river nitrate loads were, in some places, due to nitrification and, elsewhere, were due to the influx of nitrate-enriched ground water to

Water-Resources Investigations Report↗