USGS Science⌕ Search

SEARCH · USGS Science

Results for “Resource Publication”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,261 records · Page 70Linked to original sources
USGS2003

Water-quality changes and organic-carbon characterization during recharge with recycled water at a research basin in Montebello Forebay, Los Angeles County, California, 1991-1996

During the early 1990s, the U.S. Geological Survey (USGS) investigated water-quality changes that occur in treated municipal wastewater (recycled water) at a small research basin constructed in the Montebello Forebay of the Central Ground-Water Basin in south-central Los Angeles County. The instrumented research basin is located on a 1/2-acre site at the upgradient end of the San Gabriel River Coastal Spreading Grounds where recharge has been augmented using recycled water since 1961. The facility was used to measure attenuation in selected constituents as recycled water delivered to the basin percolates downward and moves laterally beneath the basin. Attenuation in aqueous concentration was found to range from 20 to 60 percent for total dissolved nitrogen and was about one-third for dissolved organic carbon (DOC). Isotopic data confirmed permanent loss of nitrogen by denitrification. Detailed investigations showed that there were no large differences in the loss of various components of the DOC at the structural or compound level, although surfactants and their metabolites were abundant and did persist in the subsurface. The DOC of wastewater origin was found to have a lower trihalomethane (THM) formation potential upon chlorination than does organic matter of natural origin from most surface-water sources. The organization of this report into 12 topical chapters, and the report's relation to additional USGS publications from this study, is noted in a preface.

Water-Resources Investigations Report↗
USGS1979

Chemical, physical, and radiological quality of selected public water supplies in Florida, November 1977-February 1978

Virtually all treated public water supplies sampled in Florida meet the National Interim Primary and Proposed Secondary Drinking Water Regulations. These findings are based on a water-quality reconnaissance of 129 treated public supplies throughout the State during the period November 1977 through February 1978. While primary drinking water regulation exceedences were infrequent, lead, selenium, and gross alpha radioactivity in a very few water supplies were above established maximum contaminant levels. Additionally, the secondary drinking water regulation parameters--dissolved solids , chloride, sulfate, iron, color, and pH--were occasionally detected in excess of the proposed Federal regulations. The secondary regulations, however, pertain mainly to the aesthetic quality of drinking water and not directly to public health aspects. (Woodard-USGS)

Water-Resources Investigations Report↗
USGS1992

Factors that affect public-supply water use in Florida, with a section on projected water use to the year 2020

Public-supply water use in Florida increased 242 percent between 1960 and 1987 from 530 Mgal/d (million gallons per day) to 1,811 Mgal/d. This change is primarily a result of increases in population and tourism since 1960. Public-supply utilities provide water to a variety of users. In 1985, 71 percent of the water used for public supply was delivered for residential uses, 15 percent for commercial uses, 9 percent for industrial uses, and the remaining 5 percent for public use or other uses. Residential use of public-supply water in Florida has increased nearly 280 Mgal/d, but has decreased in the proportion of total deliveries from 80 to 71 percent between 1975 and 1985. This trend resulted from increased tourism and related commercial services associated with population and visitors. One of several factors that influences public-supply water use in Florida is the increase in resident population, which increased from 4.95 million in 1960 to more than 12.0 million in 1987. Additionally, Florida's nonresident population increased from 18.8 million visitors in 1977, to 34.1 million visitors in 1987, and the part of Florida's population that relies on public-supply water increased from 68 percent in 1960, to 86 percent in 1987. The public supply per capita use was multiplied by the projected populations for each county for the years 2000, 2010, and 2020 to forecast public-supply water use. Using medium projections, Florida?s population is expected to increase to nearly 16 million in the year 2000, to 18 million in the year 2010, and to almost 20 million in the year 2020, of which an estimated 13.5 million people will be supplied water from public-supply water systems in the year 2000, 15 million in 2010, and nearly 17 million by the year 2020. Public-supply water use is expected to increase to a projected (medium) 2,310 Mgal/d in the year 2000, 2,610 Mgal/d in the year 2010, and 2,890 Mgal/d in the year 2020. If the population exceeds the medium projections for the years 2000, 2010, and 2020, high projections estimate public-supply water use could reach 2,570 Mgal/d in 2000, 3,210 Mgal/d in 2010, and 3,900 Mgal/d in 2020. Palm Beach County is projected to have the largest increase in public-supply water use, from 168 Mgal/d used in 1987 to a medium projected 338 Mgal/d for 2020. Dade County's public-supply water use is projected (medium) to increase to nearly 471 Mgal/d for 2020, the largest county use in Florida. Water demand options, such as conservation, restrictions, education programs, leak detection and repair programs, and more realistic pricing practices can reduce the demand for freshwater. Increased use of alternative sources of water, such as reclaimed wastewater and desalinated seawater also can reduce the demand for freshwater. Because the water demand projections in this report are based primarily on population projections, they should represent an upper limit of actual future demand if the population projections prove sound. Any additional water demand options implemented in the future at the State, county, or public-supply facility level may significantly reduce per capita use and result in public-supply use less than projected in this report.

Florida↗
USGS1977

Springs of Florida

The first comprehensive report of Florida's springs, which contains both a story of the springs and a collection of facts about them, was published thirty years ago (Ferguson and others, 1947). Since then, much additional data on springs have been gathered and the current report, Springs of Florida, makes a wealth of information on springs available to the public. Springs of Florida, prepared by the U.S. Geological Survey in cooperation with the Bureau of Geology, Florida Department of Natural Resources, publishers, and the Bureau of Water Resources Management, Florida Department of Environmental Regulation, is intended to provide sufficient background information for a lucid understanding of the nature and occurrence of the springs in the State.

Florida↗
USGS2003

StreamStats: a U.S. geological survey web site for stream information

The U.S. Geological Survey has developed a Web application, named StreamStats, for providing streamflow statistics, such as the 100-year flood and the 7-day, 10-year low flow, to the public. Statistics can be obtained for data-collection stations and for ungaged sites. Streamflow statistics are needed for water-resources planning and management; for design of bridges, culverts, and flood-control structures; and for many other purposes. StreamStats users can point and click on data-collection stations shown on a map in their Web browser window to obtain previously determined streamflow statistics and other information for the stations. Users also can point and click on any stream shown on the map to get estimates of streamflow statistics for ungaged sites. StreamStats determines the watershed boundaries and measures physical and climatic characteristics of the watersheds for the ungaged sites by use of a Geographic Information System (GIS), and then it inserts the characteristics into previously determined regression equations to estimate the streamflow statistics. Compared to manual methods, StreamStats reduces the average time needed to estimate streamflow statistics for ungaged sites from several hours to several minutes.

Conference Paper↗
USGS1990

Water-resources potential of the freshwater lens at Key West, Florida

The island of Key West lies at the end of the Florida Keys, about 150 miles southwest of Miami. The public-water supply for the island is provided by the Florida Keys Aqueduct Authority Well Field near Miami. However, there are many privately owned wells on the island that tap the local fresh ground-water lens for potable and nonpotable water supply. The number of people who use water from the wells for drinking purposes is unknown. From 1985 to 1988, the U.S. Geological Survey, in cooperation with the South Florida Water Management District, conducted an investigation to characterize the Key West freshwater lens. Observation wells were drilled to determine the extent of the lens and to characterize the water quality. Previous well logs and well-core data collected during the investigation showed the aquifer to be a highly permeable, porous, solution-riddled, oolitic limestone that allows rainfall recharge to quickly seep into the ocean and saltwater to easily intrude the aquifer. The small freshwater lens (250 milligrams per liter of chloride concentration, or less) averages 5 feet in thickness below the center of the western half (Old Town) of the island. The lens contains about 20 million gallons of fresh-water during the dry season and about 30 million gallons during the wet season. Underlying the freshwater lens is a transition zone of freshwater-saltwater mix that extends to the saltwater interface (19,000 milligrams per liter of chloride concentration), which is about 40-feet deep at the center of the lens. The water table fluctuates and the configuration of the lens constantly changes, largely as a result of tidal effects. Other events, such as rainfall, pumping, and evapotranspiration, are masked by the tidal effects. The freshwater lens is a calcium bicarbonate water that grades to a sodium chloride type near the saltwater interface. Elevated concentrations of nitrate nitrogen were found in water samples from wells in the Old Town district. However, concentrations generally were not above the maximum contaminant level of 10 milligrams per liter for drinking water established by the Florida Department of Environmental Regulation. Water samples near an old land-fill in the eastern half of the island had concentrations of iron (600-1,900 micrograms per liter) and lead (40-800 micrograms per liter) that extended maximum contaminant levels of 300 and 50 micrograms per liter. These trace-element concentrations generally decreased with distance from the landfill. Although the freshwater lens is a potential source of water for additional nonpotable water needs in Key West, any large-scale pumping could quickly exhaust the freshwater lens, and saline water could be rapidly drawn though the porous limestone aquifer. Water-quality data indicate that the lens is an unlikely source of potable water.

Florida↗
USGS2015

Modeling elk and bison carrying capacity for Great Sand Dunes National Park, Baca National Wildlife Refuge, and The Nature Conservancy's Medano Ranch, Colorado

Great Sand Dunes National Park and Preserve and the neighboring Baca National Wildlife Refuge constitute an extraordinary setting that offers a variety of opportunities for outdoor recreation and natural resource preservation in the San Luis Valley of Colorado. Adjacent to these federal lands, the Nature Conservancy (TNC) manages the historic Medano Ranch. The total land area of these three conservation properties is roughly 121,500 hectares (ha). It is a remote and rugged area in which resource managers must balance the protection of natural resources with recreation and neighboring land uses. The management of wild ungulates in this setting presents challenges, as wild ungulates move freely across public and private landscapes. The San Luis Valley was historically used for irrigated agriculture and ranching. Historically, livestock, including sheep ( Ovis aries ) and cattle ( Bos taurus ), were grazed throughout the valley. The former Luis Marie “Baca” Ranch, which makes up the northern part of Great Sand Dunes National Park (hereafter “Park”) and all of the Baca National Wildlife Refuge (hereafter “Refuge”), was actively grazed by cattle until 2004. Bison ( Bison bison ), elk ( Cervus elaphus ), mule deer ( Odocoileus hemionus ), and pronghorn ( Antilocapra americana ) were native to the area until about the 1840s, when bison, elk, and pronghorn were extirpated. Elk and pronghorn likely moved back into the area from surrounding populations to the north and south, and mule deer populations have varied through time. A population of 4,400 elk currently inhabits the area. The current bison population was established in 1986 for meat production. In 1999 TNC purchased the ranch and established a bison conservation herd, and eventually subcontracted management to a private rancher in 2005. A population of bison ranging in size from 1,200–2,000 ranges freely within the 16,100 ha Medano Ranch. Ungulate populations in the valley are regulated by hunting, with the exception of bison, which are rounded up and culled annually to maintain population levels. In an effort to create and form the basis of a multi-agency ungulate management plan for the region, the Park sought the development of an elk and bison ecological carrying capacity model to provide guidance to resource managers.

Colorado↗
USGS1986

Water supplies in western Kentucky during 1984

An inventory was conducted between April and October 1985 of 101 major public supply systems and of self-supplied commercial and industrial water systems in a 27-county area in western Kentucky. These systems, because they withdraw at least 10,000 gal/day (gpd), are regulated by the Kentucky Natural Resources and Environmental Projection Cabinet (Division of Water) through a permitting program. The major purpose of the inventory was to evaluate the adequacy of these water systems to meet demands during times of drought. The inventory indicated that these systems withdrew 116.3 million gpd in 1984. The study showed that public facilities supplied 33.1 mil gpd to 471,500 people. Bowling Green Municipal Utilities in the Green River basin was the largest single public supplier. It supplied 5.05 million gpd to 48,000 people, and also sold over 1.7 million gpd to about 30 ,000 people through the Warren County Water System. Comparisons of ground- and surface-water use indicated the Lower Ohio River basin had the highest percentage of surface-water use at 97%, and the Mississippi River basin had the highest percentage of groundwater use at 41%. Sources of water were generally adequate throughout the study area. Sources for two industries, also in the Green River basin, are inadequate. Six systems may have potential problems with their treatment plant capacities because they are operating at > 80% of design capacity. Three of these systems are in the Green River basin, two are in the Lower Cumberland River basin, and one is in the Tennessee River basin. (Author 's abstract)

Water-Resources Investigations Report↗
USGS1998

Digital Geologic Map of the Rosalia 1:100,000 Quadrangle, Washington and Idaho: A Digital Database for the 1990 S.Z. Waggoner Map

The geologic map of the Rosalia 1:100,000-scale quadrangle was compiled in 1990 by S.Z. Waggoner of the Washington state Division of Geology and Earth Resources. This data was entered into a geographic information system (GIS) as part of a larger effort to create regional digital geology for the Pacific Northwest. The intent was to provide a digital geospatial database for a previously published black and white paper geologic map. This database can be queried in many ways to produce a variety of geologic maps. Digital base map data files are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:100,000 (e.g., 1:62,500 or 1:24,000) as it has been somewhat generalized to fit the 1:100,000 scale map. The map area is located in eastern Washington and extends across the state border into western Idaho. This open-file report describes the methods used to convert the geologic map data into a digital format, documents the file structures, and explains how to download the digital files from the U.S. Geological Survey public access World Wide Web site on the Internet. We wish to thank J. Eric Schuster of the Washington Division of Geology and Earth Resources for providing the original stable-base mylar and the funding for it to be scanned. We also thank Dick Blank and Barry Moring of the U.S. Geological Survey for reviewing the manuscript and digital files, respectively.

Open-File Report↗
USGS2009

Water Withdrawals, Use, and Wastewater Return Flows in the Concord River Basin, Eastern Massachusetts, 1996-2000

Water withdrawals, use, and wastewater return flows for the Concord River Basin were estimated for the period 1996-2000. The study area in eastern Massachusetts is 400 square miles in area and includes the basins of two major tributaries, the Assabet and Sudbury Rivers, along with the Concord River, which starts at the confluence of the two tributaries. About 400,000 people lived in the basin during the study period, on the basis of an analysis of census data, land use, and population density. Public water systems served an estimated 87 percent of the people in the basin, and public wastewater systems served an estimated 65 percent of the basin population. The estimates of water withdrawals, use, wastewater return flows, and imports and exports for the Concord River Basin and 25 subbasins provide information that can be used in hydrologic analyses such as water budgets and can guide water-resources allocations for human and environmental needs. Withdrawals in the basin were estimated at 12,700 million gallons per year (Mgal/yr) during the study period, of which 10,100 Mgal/yr (about 80 percent) were withdrawn by public water-supply systems and 2,650 Mgal/yr were self-supplied by individual users. Water use in the basin and subbasins was estimated by using water withdrawals, average per capita use rates (about 72 gallons per day per person), land-use data, estimated population densities, and other information. Total water use in the basin, which included imports, was 19,200 Mgal/yr and was provided mostly (86.2 percent) by public supply. Domestic use (11,300 Mgal/yr) was the largest component, accounting for about 60 percent of total water use in the basin. Commercial use (3,770 Mgal/yr), industrial use (1,330 Mgal/yr), and agricultural use (including golf-course irrigation; 562 Mgal/yr) accounted for 19.6, 6.9, and 2.9 percent, respectively, of total use. Water that was unaccounted for in public-supply systems was estimated at 2,260 Mgal/yr, or 11.8 percent of total water use in the basin. Wastewater return flows discharged in the basin were estimated at 11,800 Mgal/yr, of which 6,620 Mgal/yr were discharged from municipal wastewater-treatment facilities to surface waters and 5,190 Mgal/yr were self-disposed through septic systems to ground water; wastewater disposed through septic systems was generated by both public- and self-supply use. Water use and management in the Concord River Basin resulted in an estimated import of 6,460 Mgal/yr of potable water for public supply and an estimated export of 6,590 Mgal/yr of wastewater. Water was imported into the Assabet, Sudbury, and Lower Concord (the area draining directly to the Concord River) River Basins for public supply. Wastewater was imported into the Assabet River Basin, but exported from the Sudbury and Lower Concord River Basins. Of the 25 subbasins in the Concord River Basin for which water use was analyzed, 20 subbasins imported potable water, 4 subbasins exported potable water (Fort Meadow Brook, Indian Brook, Lower Sudbury River, and Whitehall Brook), and potable water was neither imported nor exported in one subbasin (Elizabeth Brook). Wastewater was imported into the Assabet Headwaters, Assabet Main Stem, and Hop Brook subbasins; wastewater was neither imported to nor exported from the Elizabeth Brook, Nashoba Brook, and Pine Brook subbasins; and wastewater was exported from all other subbasins. Water use and management in the basin also resulted in a net transfer of water from ground water to surface water, discharged as wastewater, of about 4,000 Mgal/yr.

Scientific Investigations Report↗
USGS2009

Water Resources of Ascension Parish

Ascension Parish, located along the banks of the Mississippi River in south-central Louisiana, contains fresh groundwater and surface-water resources. In 2005, about 202 million gallons per day (Mgal/d) were withdrawn from water sources in Ascension Parish. About 94 percent (190 Mgal/d) was withdrawn from surface water, and 6 percent (12 Mgal/d) was withdrawn from groundwater. Additional water is supplied to Ascension Parish for public-supply use from East Baton Rouge Parish. Withdrawals for industrial use accounted for 95 percent (192 Mgal/d) of the total water withdrawn. Withdrawals for other uses included public-supply (4 Mgal/d), rural-domestic (3 Mgal/d), and aquaculture (3 Mgal/d). Water withdrawals in the parish generally increased from 1960 to 1995 and decreased from 1995 to 2005. This fact sheet summarizes basic information on the water resources of Ascension Parish, La. Information on groundwater and surface-water availability, quality, development, use, and trends is based on previously published reports listed in the references section.

Fact Sheet↗
USGS1994

Ground-water resources of Okeechobee County, Florida

Rapid population growth in Okeechobee County, Florida will increase future demand for potable water. Much of the ground water within the county is vulnerable to saltwater upconing or recharge water of poor-quality from the land surface. The surficial aquifer system within the county is a major source of domestic and public water supply. This system consists of sand, silt, and shell and has a maximum thickness of about 250 feet. Water in the surficial aquifer system is generally potable except in areas where brackish water has intruded from wells tapping the Floridan aquifer system. The Floridan aquifer system is a sequence of limestone and dolomite that is about 2,500 feet thick. Water in the Floridan aquifer system ranges from marginally potable to brackish. Use of this aquifer system for public water supply is limited because the potable water is not located near population centers. The Floridan aquifer system is used extensively for agricultural irrigation.

Water-Resources Investigations Report↗
USGS2025

Preserving and increasing water resources—Natural infrastructure in dryland streams in Baja California Sur, Mexico

The Los Planes watershed of Baja California Sur, Mexico, and its underlying aquifer are experiencing groundwater decline owing to low average annual rainfall (28.1 centimeters per year) and rising water demand from population growth and agricultural activities. This decline in water availability can lead to desertification—a process that changes arable land to desert by degrading soil and vegetation—and can pose serious challenges to livelihoods that depend on the land. To address these issues, a ranch in the Los Planes watershed has installed many natural infrastructures in dryland streams (NIDS) in channels for soil and water conservation. In 2022, the U.S. Geological Survey (USGS) began working with regional researchers and land managers to investigate the effects of NIDS on natural biological, geochemical, and physical processes and determine the efficacy of NIDS for water augmentation in the Los Planes watershed. The USGS also worked with local academic institutions and nonprofit organizations to create public educational opportunities focused on the area’s hydrogeology. These and other collaborative efforts with the U.S. Water Partnership and Innovaciones Alumbra aim at enhancing water resources in the Baja California Sur region and promoting water security and safeguarding community well-being. Resume La cuenca de Los Planes, ubicada en Baja California Sur, México, y su acuífero subyacente, están sufriendo una disminución de las aguas subterráneas debido a la baja precipitación media anual (28.1 centímetros por año) y la alta demanda de agua por parte de una población creciente y la actividad agrícola. Esta disminución de la disponibilidad de agua puede conducir a la desertificación—un proceso que por medio de la degradación del suelo y la vegetación convierte a la tierra cultivable en desierto—representando un serio desafío para los medios de vida de las personas. Para abordar estos problemas, un rancho en la cuenca de Los Planes ha instalado numerosas obras de Infraestructura Natural en Arroyos de Tierras Áridas (INATS) para conservación del suelo y del agua. En 2022, el Servicio Geológico de los Estados Unidos (USGS, por sus siglas en inglés) comenzó a trabajar con investigadores regionales y gestores de tierras para estudiar los efectos de INATS en los procesos biológicos, geoquímicos y físicos, y determinar su eficacia en el aumento de los recursos hídricos en la cuenca de Los Planes. El USGS se ha asociado con instituciones académicas y organizaciones locales sin fines de lucro para crear oportunidades educativas públicas centradas en la hidrogeología de la zona. Estos y otros esfuerzos colaborativos con la Asociación del Agua de Estados Unidos (U.S. Water Partnership) e Innovaciones Alumbra, tienen como objetivo mejorar el uso de los recursos hídricos en la región de Baja California Sur, promover la seguridad hídrica y proteger el bienestar de la comunidad.

Baja California Sur↗
USGS2003

Sediment-hosted copper deposits of the world: Deposit models and database

Introduction This publication contains four descriptive models and four grade-tonnage models for sediment hosted copper deposits. Descriptive models are useful in exploration planning and resource assessment because they enable the user to identify deposits in the field and to identify areas on geologic and geophysical maps where deposits could occur. Grade and tonnage models are used in resource assessment to predict the likelihood of different combinations of grades and tonnages that could occur in undiscovered deposits in a specific area. They are also useful in exploration in deciding what deposit types meet the economic objectives of the exploration company. The models in this report supersede the sediment-hosted copper models in USGS Bulletin 1693 (Cox, 1986, and Mosier and others, 1986) and are subdivided into a general type and three subtypes. The general model is useful in classifying deposits whose features are obscured by metamorphism or are otherwise poorly described, and for assessing regions in which the geologic environments are poorly understood. The three subtypes are based on differences in deposit form and environments of deposition. These differences are described under subtypes in the general model. Deposit models are based on the descriptions of geologic environments and physical characteristics, and on metal grades and tonnages of many individual deposits. Data used in this study are presented in a database representing 785 deposits in nine continents. This database was derived partly from data published by Kirkham and others (1994) and from new information in recent publications. To facilitate the construction of grade and tonnage models, the information, presented by Kirkham in disaggregated form, was brought together to provide a single grade and a single tonnage for each deposit. Throughout the report individual deposits are defined as being more than 2,000 meters from the nearest adjacent deposit. The deposit models are presented here as a PDF file. The database can be most conveniently read in FileMaker Pro. For those who do not have the FileMaker application, Microsoft-Excel, tab-delimited-ASCII and comma-separated-value files are included. The reader may be interested in a similar publication on porphyry copper deposits (Singer and others, 2005) also available online. The Google Earth image is not intended to be viewed at the highest possible magnification because the resolution of the database is plus or minus two kilometers. At extreme zoom settings, the deposit locations may not coincide with the Google-Earth images of the mine workings.

Open-File Report↗
USGS2026

Recent scientific contributions by the U.S. Geological Survey in the San Francisco Bay and Sacramento–San Joaquin Delta Estuary

Introduction The San Francisco Bay and Sacramento–San Joaquin Delta Estuary (hereafter, Bay-Delta) is the largest estuary on the West Coast of the United States. The Bay-Delta covers more than 1,600 square miles and drains a watershed of more than 75,000 square miles, which is greater than 40 percent of California. The region surrounding the Bay-Delta is home to about 10 million people, and its habitats (fig. 1) support more than 800 plant and animal species. The waterways of the Bay-Delta are the central hub of California’s extensive freshwater delivery system, supplying water to more than 27 million Californians and 4 million acres of farmland in the Central Valley. The U.S. Geological Survey (USGS) is the primary science agency of the U.S. Department of the Interior, providing a broad range of Earth, water, biological, and mapping data and expertise to inform natural resource management across the country. This fact sheet focuses on research conducted by the USGS in the Bay-Delta region, mostly within the past 5 years. The fact sheet is organized across five major themes: water flow and water quality, fish and wildlife, wetland restoration, invasive species, and hazards. In each of these areas, the USGS works closely with Federal, State, and local agencies; academia; and non-governmental organizations to provide objective, evidence-based science. The data and knowledge gained from USGS research and monitoring are publicly available and are routinely used by agencies, including the U.S. Bureau of Reclamation, U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, California Department of Water Resources, California Department of Fish and Wildlife, California State Water Resources Control Board, Delta Stewardship Council, and many additional organizations and stakeholders to inform management of the Bay-Delta region and its resources.

California↗
USGS2005

Wildlife as valuable natural resources vs. intolerable pests: A suburban wildlife management model

Management of wildlife in suburban environments involves a complex set of interactions between both human and wildlife populations. Managers need additional tools, such as models, that can help them assess the status of wildlife populations, devise and apply management programs, and convey this information to other professionals and the public. We present a model that conceptualizes how some wildlife populations can fluctuate between extremely low (rare, threatened, or endangered status) and extremely high (overabundant) numbers over time. Changes in wildlife abundance can induce changes in human perceptions, which continually redefine species as a valuable resource to be protected versus a pest to be controlled. Management programs thatincorporate a number of approaches and promote more stable populations of wildlife avoid the problems of the resource versus pest transformation, are less costly to society, and encourage more positive and less negative interactions between humans and wildlife. We presenta case example of the beaver Castor canadensis in Massachusetts to illustrate how this model functions and can be applied. ?? 2005 Springer Science + Business Media, Inc.

Urban Ecosystems↗
USGS2000

Water quality of selected springs and public-supply wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

This report presents results of a water-quality study for the Pine Ridge Indian Reservation, South Dakota. The study was a cooperative effort between the U.S. Geological Survey and the Water Resources Department of the Oglala Sioux Tribe. Discharge and water-quality data were collected during 1992-97 for 14 contact springs located in the northwestern part of the Reservation. Data were collected to evaluate potential alternative sources of water supply for the village of Red Shirt, which currently obtains water of marginal quality from a well completed in the Inyan Kara aquifer. During 1995-97, water-quality data also were collected for 44 public-supply wells that serve about one-half of the Reservation's population. Quality-assurance sampling was used to evaluate the precision and accuracy of environmental samples. Ten of the springs sampled contact the White River Group, and four contact the Pierre Shale. Springs contacting the White River Group range from calcium bicarbonate to sodium bicarbonate water types. Two springs contacting the Pierre Shale have water types similar to this; however, sulfate is the dominant anion for the other two springs. In general, springs contacting the White River Group are shown to have better potential as alternative sources of water supply for the village of Red Shirt than springs contacting the Pierre Shale. Nine of the springs with better water quality were sampled repeatedly; however, only minor variability in water quality was identified. Six of these nine springs, of which five contact the White River Group, probably have the best potential for use as water supplies. Discharge from any of these six springs probably would provide adequate water supply for Red Shirt during most periods, based on a limited number of discharge measurements collected. Concentrations of lead exceeded the U.S. Environmental Protection Agency (USEPA) action level of 15 µg/L for three of these six springs. Five of these six springs also had arsenic concentrations that exceeded 10 µg/L, which could be problematic if the current maximum contaminant level (MCL) is lowered. Blending of water from one or more springs with water from the existing Inyan Kara well may be an option to address concerns regarding both quantity and quality of existing and potential sources. All nine springs that were sampled for indicator bacteria had positive detections on one or more occasions during presumptive tests. Although USEPA standards for bacteria apply only to public-water supplies, local residents using spring water for domestic purposes need to be aware of the potential health risks associated with consuming untreated water. One spring contacting the White River Group and two springs contacting the Pierre Shale exceeded 15 pCi/L for gross alpha; these values do not necessarily constitute exceedances of the MCL, which excludes radioactivity contributed by uranium and radon. Additional sampling using different analysis techniques would be needed to conclusively determine if any samples exceeded this MCL. Nine springs were sampled for selected pesticides and tritium. The pesticides atrazine, carbaryl, and 2,4-D were not detected in any of the samples. The nine springs were analyzed for tritium in order to generally assess the age of the water and to determine if concentrations exceeded the MCL established for gross beta-particle activity. Tritium results indicated two springs are composed primarily of water recharged prior to atmospheric testing of nuclear bombs and two other springs have a relatively large percentage of test-era water. The remaining five springs had tritium values that indicated some percentage of test-era water; however, additional sampling would be needed to determine whether water is predominantly pre- or post-bomb age. Of the 44 public-supply wells sampled, 42 are completed in the Arikaree aquifer, one is completed in an alluvial aquifer, and one is completed in the Inyan Kara aquifer. Water from the alluvial well is a sodium bicarbonate water type, water from Arikaree aquifer ranges from calcium bicarbonate to sodium bicarbonate types, and water from the Inyan Kara well is a calcium sulfate bicarbonate type. Of the 44 wells sampled, 28 (64 percent) tested positive for indicator bacteria in presumptive tests. Because these were single samples that generally were collected upstream from chemical treatment feeders, positive detections do not necessarily constitute exceedances of drinking-water standards. A single sample from an Arikaree well exceeded the MCL for arsenic of 50 µg/L. Arsenic exceeded 10 µg/L for six additional Arikaree wells and for the alluvial well and the Inyan Kara well, which could be problematic if the current MCL is lowered. The alluvial well also exceeded the secondary maximum contaminant level (SMCL) for dissolved solids, which is non-enforceable, and the action level for lead. The Inyan Kara well exceeded the SMCL's for iron and for manganese and the MCL of 5 pCi/L for radium-226 and 228 combined. Several Arikaree wells exceeded SMCL's for either pH, sulfate, dissolved solids, iron, or manganese. One Arikaree well exceeded the MCL of 4.0 mg/L for fluoride and another exceeded the MCL of 10 mg/L for nitrite plus nitrate. Ten Arikaree wells equalled or exceeded 15 pCi/L for gross alpha; however, these values do not necessarily constitute exceedances of the MCL, which excludes radioactivity contributed by uranium and radon. Additional sampling using different analysis techniques would be needed to conclusively determine if any samples exceeded this MCL. Eight wells, all from the Arikaree aquifer, equalled or exceeded the proposed MCL of 20 µg/L for uranium and 33 wells (75 percent) equalled or exceeded one-half of the proposed MCL. Although this standard has only been proposed, additional information regarding the extent of elevated uranium concentrations in the Arikaree aquifer, and the geochemical processes involved, may be beneficial. It was determined from analyses of uranium isotope data for five wells that the source of elevated uranium concentrations is naturally occurring, rather than anthropogenic.

South Dakota↗
USGS1993

Water resources of Big Horn County, Wyoming

Groundwater in unconsolidated aquifers is the most reliable and accessible source of potable water in Big Horn County, Wyoming. Well yields generally ranged from 25 to 200 gal/min; however, yields of 1600 gal/min are reported from wells in the gravel, pediment, and fan deposits. Bedrock aquifers that yield the most abundant water supplies are the Tensleep Sandstone, Madison Limestone, Bighorn Dolomite, and Flathead Sandstone. The aquifers with the most potential for development as a water supply, predominately composed of sandstone, are the Lance, Mesaverde, and Frontier Formations. The Madison Limestone, the Darby Formation, and the Bighorn Dolomite form the Madison Bighorn aquifer. Reported yields from the aquifer ranged from 40 to 14,000 gal/min. Flowing wells from the Madison-Bighorn aquifer had shut-in pressures ranging from 41 to 212 pounds per square inch (95 to 490 feet above land surface). Shut-in pressures from flowing wells in bedrock indicate declines, from the time the wells were completed to 1988, as much as 390 feet. Flows have also decreased over time. Water samples from wells completed in unconsolidated aquifers have concentrations of dissolved solids less than 2,000 mg/L (milligrams per liter). Water from unconsolidated aquifers are classified as a calcium sulfate type, a sodium sulfate type, and sodium-calcium sulfate type. Water samples from wells completed in aquifers in Paleozoic and Precambrian rocks had median concentrations of dissolved solids ranging from 111 to 275 mg/L. Water samples from wells in Tertiary and Cretaceous rocks had a median concentration of dissolved solids ranging from 1,107 to 3,320 mg/L. Water types for these aquifers were usually sodium sulfate. Perennial streams originate in the mountains and ephemeral streams originate in the Bighorn Basin. Irrigation return-flow to streams maintains perennial flow in what would otherwise be ephemeral streams. Streams that originate in the Bighorn Basin have specific conductance values generally greater than 1,000 mg/L, whereas streams that originate in the Bighorn Mountains have specific conductance values generally less than 1,000 mg/L. The predominant dissolved constituents are calcium or sodium and bicarbonate or sulfate. Concentrations of pesticides detected in surface-water samples were less than the U.S. Environmental Protection Agency (USHPA) maximum contaminant levels. The detected concentrations of pesticides in streambed material in the organochlorine insecticide class ranged from 0.1 to 8.0 micrograms per kilogram. Pesticides detected in ground-water samples included dicamba and picloram at a concentration of 0.40 jig/L (micrograms per liter), atrazines (0.40 jig/L), aldicarb sulfone (1.44 |ig/L), aldicarb sulfoxide (0.52 |ig/L), and malathion (0.02 jig/L). Analyses of ground-water samples for radionuclides indicate that concentrations from four municipal wells exceeded the maximum contaminant level established by the USEPA. Of these four wells, concentrations in water samples from the municipal well at Frannie consistently exceeded the USEPA maximum contaminant level for dissolved gross alpha activity of 15 pCi/L (picocuries per liter) and radium-226 plus radium-228 (5 pCi/L). The source of the radioactivity is postulated to be the Madison Limestone. Surface water accounts for 96 percent and ground water accounts for 4 percent of total offstream water use in Big Horn County, Wyoming. Irrigation is the largest offstream use of both surface and ground water. About 99 percent of offstream surface water and 55 percent of ground water is used for irrigation. Eighty-two percent of the water used for irrigation is consumed, which includes a 37-percent conveyance loss and 45 percent consumed by the irrigated crops. Ground water supplies 89 percent of water used for domestic purposes and about 16 percent of water used for public supplies, which shows that ground water is a primary domestic water supply in rural areas where public supplies are not available.

Wyoming↗