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At least 1,045 records · Page 58Linked to original sources

Water resources data for California, water year 1975; Volume 3: Southern Central Valley Basins and The Great Basin from Walker River to Truckee River

Water-resources data for the 1975 water year for California consist of records of streamflow and contents of reservoirs at gaging stations, partial-record stations, and miscellaneous sites; records of water quality including the physical, chemical, and biological characteristics of surface and ground water; and records of water levels in selected observation wells. Records for a few pertinent streamflow and water-quality stations in bordering States are also included. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Lee R. Peterson, district chief; Winchell Smith, assistant district chief for hydrologic data; and Leonard N. Jorgensen, chief of the basic data section. These data represent that part of the National Water Data System collected by the Geological Survey and cooperating local, State, and Federal agencies in California.

California↗

Water resources data for California, water year 1975; Volume 4: Northern Central Valley basins and the Great Basin from Honey Lake basin to Oregon state line

Water-resources data for the 1975 water year for California consist of records of streamflow and contents of reservoirs at gaging stations, partial-record stations, and miscellaneous sites; records of water quality including the physical, chemical, and biological characteristics of surface and ground water; and records of water levels in selected observation wells. Records for a few pertinent streamflow and water-quality stations in bordering States are also included. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Lee R. Peterson, district chief; Winchell Smith, assistant district chief for hydrologic data; and Leonard N. Jorgensen, chief of the basic data section. These data represent that part of the National Water Data System collected by the Geological Survey and cooperating local, State, and Federal agencies in California.

California↗

The U.S. Geological Survey Federal-State cooperative water- resources program; fiscal year 1987

The U.S. Geological Survey 's Federal-State Cooperative Water Resources Program (50-50 matching of funds) started in Kansas in 1895. During fiscal year (FY) 1987, hydrologic data collection, investigations, and research are being conducted in every state, Puerto Rico, and several territories in cooperation with 940 state, regional and local agencies. Federal funding of $55.3 million was matched by cooperating agencies; cooperators also provided $4.6 million unmatched, for a program total of about $115 million. The Cooperative Program accounted for almost 45% of the FY 1987 obligations of the Geological Survey 's Water Resources Division. The principal areas of emphasis during the year included groundwater contamination, stream quality, water supply and demand, and hydrologic hazards. Information is presented on program functions and priorities. Data collection activities are also described as is work related to water resources contamination. Several examples of current (1987) investigations are provided. (Author 's abstract)

Open-File Report↗

Estimation of water surface elevations for the Everglades, Florida

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring gages and modeling methods that provides scientists and managers with current (2000–present) online water surface and water depth information for the freshwater domain of the Greater Everglades. This integrated system presents data on a 400-m square grid to assist in (1) large-scale field operations; (2) integration of hydrologic and ecologic responses; (3) supporting biological and ecological assessment of the implementation of the Comprehensive Everglades Restoration Plan (CERP); and (4) assessing trophic-level responses to hydrodynamic changes in the Everglades. This paper investigates the radial basis function multiquadric method of interpolation to obtain a continuous freshwater surface across the entire Everglades using radio-transmitted data from a network of water-level gages managed by the US Geological Survey (USGS), the South Florida Water Management District (SFWMD), and the Everglades National Park (ENP). Since the hydrological connection is interrupted by canals and levees across the study area, boundary conditions were simulated by linearly interpolating along those features and integrating the results together with the data from marsh stations to obtain a continuous water surface through multiquadric interpolation. The absolute cross-validation errors greater than 5 cm correlate well with the local outliers and the minimum distance between the closest stations within 2000-m radius, but seem to be independent of vegetation or season.

Florida↗

Temperature and water-quality diversity and the effects of surface-water connection in off-channel features of the Willamette River, Oregon, 2015–16

Water-quality conditions (including temperature) in the Willamette River and many of its adjacent off-channel features, such as alcoves and side channels, were monitored between river miles 67 (near Salem, Oregon) and 168 (near Eugene, Oregon) during the summers of 2015 and 2016. One or more parameters (water temperature, dissolved oxygen, pH, specific conductance, and [or] water depth) were continuously measured at sites in the main channel (9 sites in 2015; 5 sites in 2016) and select off-channel features (20 features in 2015; 22 features in 2016). This study was initiated in reaction to the unusually warm, dry weather and resulting low streamflows that occurred in the Pacific Northwest in 2015 and the need for flow managers to understand the effects of streamflow on water-quality conditions in off-channel features of the Willamette River. Field monitoring was focused on documenting water-quality conditions during low summer streamflows and during fluctuations in streamflow, including when side channels became alcoves and reconnected to become side channels again. Water in the main channel of the Willamette River upstream from river mile 50 near Newberg typically is well mixed during summer, with warm water temperatures (greater than 18 degrees Celsius) and high dissolved-oxygen concentrations (often greater than 7.7 milligrams per liter). During low summer flows, a diverse suite of off-channel features exists adjacent to the main channel of the Willamette River. Despite temporal and spatial variability within individual features, comparison of continuous water-temperature data between the main channel and off-channel features indicated that some off-channel features were consistently cooler than the main channel, some were consistently warmer than the main channel, and others frequently fluctuated between warmer or cooler than the main channel. Site-specific characteristics including upstream connection, depth, and presence or absence of aquatic or riparian vegetation were factors that seemed to affect the water quality of a feature. Results from this study showed a relation between the geomorphology, hydrology, ecology, and water quality of an off-channel feature. Data confirmed that many features that can be classified as cold-water refuges based on water-temperature standards also contained low concentrations of dissolved oxygen that may not be suitable for sensitive fish species. A simplified site classification scheme is proposed that links water-quality conditions in measured off-channel features with site-specific characteristics and summer streamflows. The site classification scheme was extended to create a theoretical process matrix that relates measured water-quality conditions to a list of the processes and site-specific characteristics that could create those conditions.

Oregon↗

Hydrogeologic framework and conceptual groundwater-flow model of the panhandle and northwest parts of the High Plains (Ogallala) aquifer in Oklahoma, 1998–2022

This study was conducted by the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, to update the hydrogeologic framework and conceptual flow model for the panhandle and northwest parts of the High Plains (Ogallala) aquifer in Oklahoma, which together compose the Ogallala aquifer focus area. The study included the construction of a potentiometric surface, and available geologic and hydrologic data were used to evaluate saturated thickness of the aquifer. The water budget for the updated conceptual groundwater-​flow model was based on estimated inflows and outflows for the 1998–2022 study period. Saturated thickness of the Ogallala aquifer averaged 127 and 116 feet for the panhandle and northwest parts, respectively. Groundwater withdrawals from the Ogallala aquifer for 1998–2022 averaged 422,054 and 39,645 acre-feet per year (acre-ft/yr) for the panhandle and northwest parts, respectively. Recharge, the primary inflow, was estimated at 0.63 inch per year for the 1998–2022 study period, with the panhandle part of the Ogallala aquifer receiving 175,068 acre-ft/yr and the northwest part of the Ogallala aquifer receiving 49,376 acre-ft/yr. Additional inflows included irrigation return flows, estimated at 8,111 and 642 acre-ft/yr for the panhandle and northwest parts, respectively, of the Ogallala aquifer. Net lateral groundwater flows, considered to be aquifer outflows, were estimated to account for 31,908 acre-ft/yr for the Ogallala aquifer focus area. Streambed seepage, which was an outflow of 5,535 acre-ft/yr, was only present in the northwest part of the Ogallala aquifer. Vertical leakage and saturated-zone evapotranspiration were considered negligible outflows. These findings provide a revised conceptual groundwater-flow model water budget for the Ogallala aquifer focus area in Oklahoma.

Colorado, Kansas, Oklahoma, Texas↗

Applications of isotopes to tracing sources of solutes and water in shallow systems

New awareness of the potential danger to water supplies posed by the use of agricultural chemicals has focused attention on the nature of groundwater recharge and the mobility of various solutes, especially nitrate and pesticides, in shallow systems. A better understanding of hydrologic flowpaths and solute sources is required to determine the potential impact of sources of contamination on water supplies, to develop management practices for preserving water quality, and to develop remediation plans for sites that are already contaminated. In many cases, environmental isotopes can be employed as 'surgical tools' for answering very specific questions about water and solute sources. Isotopic data can often provide more accurate information about the system than hydrologic measurements or complicated hydrologic models. This note focuses on practical and cost-effective examples of how naturally-occurring isotopes can be used to track water and solutes as they move through shallow systems.

Conference Paper↗

Selected hydrologic data, Uinta Basin area, Utah and Colorado

The Uinta Basin area in northeastern Utah and northwestern Colorado covers an area of slightly more than 10,000 mi 2 (25,900 km 2 ). More than 95 percent of the basin is in Utah, thus most of the data in this report apply to Utah. Most of the water wells are concentrated in populated areas along the lower parts of the basin; records of only a representative number of these water sources are included in this report. This report presents consolidated listings of data selected for use in hydrologic studies in the Uinta Basin area through June 1974. The data are principally taken from three studies made during 1971-74 by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights. Also incorporated in this report are data collected since 1935 by the Geological Survey and other organizations. This report is intended to make data conveniently available and to supplement interpretive reports that will be published separately. For some data sites, the volume of data is too great for complete inclusion here. For these sites, data summaries are provided, and for greater detail the reader is referred to the sources listed under Selected references.

Colorado, Utah↗

Groundwater hydrology and estimation of horizontal groundwater flux from the Rio Grande at selected locations in Albuquerque, New Mexico, 2009–10

The Albuquerque area of New Mexico has two principal sources of water: (1) groundwater from the Santa Fe Group aquifer system, and (2) surface water from the Rio Grande. From 1960 to 2002, pumping from the Santa Fe Group aquifer system caused groundwater levels to decline more than 120 feet while water-level declines along the Rio Grande in Albuquerque were generally less than 40 feet. These differences in water-level declines in the Albuquerque area have resulted in a great deal of interest in quantifying the river-aquifer interaction associated with the Rio Grande. In 2003, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, acting as fiscal agent for the Middle Rio Grande Endangered Species Collaborative Program, and the U.S. Army Corps of Engineers, began a study to characterize the hydrogeology of the Rio Grande inner valley alluvial aquifer in the Albuquerque area of New Mexico. The study provides hydrologic data in order to enhance the understanding of rates of water leakage from the Rio Grande to the alluvial aquifer, groundwater flow through the aquifer, and discharge of water from the aquifer to riverside drains. The study area extends about 20 miles along the Rio Grande in the Albuquerque area. Piezometers and surface-water gages were installed in paired transects at eight locations. Nested piezometers, completed at various depths in the alluvial aquifer, and surface-water gages, installed in the Rio Grande and riverside drains, were instrumented with pressure transducers. Water-level and water-temperature data were collected from 2009 to 2010. Water levels from the piezometers indicated that groundwater movement was usually away from the river towards the riverside drains. Annual mean horizontal groundwater gradients in the inner valley alluvial aquifer ranged from 0.0024 (I-25 East) to 0.0144 (Pajarito East). The median hydraulic conductivity values of the inner valley alluvial aquifer, determined from slug tests, ranged from 30 feet per day (ft/d) (Montaño) to 120 ft/d (Central) for paired transects, with a median hydraulic conductivity for all transects of 50 ft/d. Daily mean groundwater fluxes from the river through the inner valley alluvial aquifer computed using Darcy’s Law and the slug test results ranged from about 0.01 ft/d (Montaño West) to between 1.0 and 2.0 ft/d (Central East). Median annual groundwater fluxes from the river through the inner valley alluvial aquifer determined using the Suzuki-Stallman method was greatest at Alameda East (0.50 ft/d) and lowest at Alameda West (0.25 ft/d). The results from both methods agreed reasonably well. Seepage investigations conducted by measuring discharge in the east and west riverside drains provided information for computing changes in flow within the drains and for evaluating results from Darcy’s Law and Suzuki-Stallman method flux calculations. Discharge measured in the east riverside drain between the Barelas Bridge and the I-25 bridge indicated that the flow in the east riverside drain increased by an average of 56.5 cubic feet per day per linear foot (ft 3 /d/ft) of drain. Discharge measured in the west riverside drain between the Central bridge and the I-25 bridge indicated that flow increased between west drain miles 0 and 4, an average of 53.8 ft 3 /d/ft of drain, and that flow increased between west drain miles 7 and 10, an average of 44.9 ft 3 /d/ft of drain. In comparison to the seepage measurement results, the groundwater fluxes from the river through the inner valley alluvial aquifer calculated from Darcy’s Law (q slug ) and by the Suzuki-Stallman method (q heat ) would account for 20–36 percent or 53–95 percent, respectively, of the total flow in the east riverside drain and 22–31 percent or 19–26 percent, respectively, of the total flow in the west drain. These results indicate that the drains likely also receive water from outside the inner valley. The spatial variability of horizontal hydraulic gradients and groundwater fluxes can be primarily attributed to variability in the distances between the river and riverside drains throughout the study area and geologic heterogeneities in the alluvial aquifer. Temporal variability in the water levels, which control the horizontal hydraulic gradients and fluxes between the Rio Grande and the riverside drains, can be primarily attributed to seasonal fluctuations in river stage and irrigation practices.

New Mexico↗

Ground-water levels, flow, and quality in northwestern Elkhart County, Indiana, 1980-89

Ground-water data were collected in northwestern Elkhart County, Indiana, from 1980 through 1989 to monitor hydrologic conditions and to provide information necessary for waterresources managers to evaluate the ground-water resources in this area. The area of study includes a closed industrial landfill and several areas of industrial and municipal pumping. Water levels were measured twice a year in 68 wells, and water samples were collected once a year from 32 wells. The wells were screened in unconsolidated glacial-outwash deposits primarily sand and gravel. During the study, measured ground-water levels ranged from about 6 feet above ground level to about 29 feet below ground level. The average depth to water for all wells was 10 feet, and the average water-level fluctuation for the entire study period was 4.8 feet. In the study area, ground water flows toward the St. Joseph River. Water levels near the river are higher than the stage of the river, indicating that ground water is discharged to the river. Water samples were collected and analyzed to determine concentrations of dissolved bromide. Onsite measurements of specific conductance, pH, water temperature, and concentrations of dissolved oxygen and alkalinity were made at the time of sampling. The water samples had a median specific conductance of 516 microsiemens per centimeter at 25 degrees Celsius, a median ph of 7.6, a median alkalinity of 216 milligrams per liter (as calcium carbonate), and a median dissolved-bromide concentration of 0.08 milligrams per liter. Water-quality data were grouped according to the depth and position of the wells in the flow system with respect to the closed industrial landfill. Shallow wells are those less than 100 feet deep; deep wells are those more than 100 feet deep. Comparison among groups indicates that water from shallow wells downgradient from the landfill had larger values of specific conductance, larger concentrations of alkalinity and dissolved bromide, and smaller values of pH than did water from shallow wells upgradient from the landfill and water from deep wells throughout the study area. Concentrations of dissolved bromide were used to estimate the extent of the landfill's effect on ground-water quality by plotting and contouring the concentration values on maps and hydrogeologic sections. The maps show a plume of bromide extending south of the landfill along the direction of groundwater flow. The hydrogeologic sections indicate that water containing bromide is moving vertically downward in the unconfined aquifer beneath and downgrfldient from the landfill. Maps and sections for different time periods were compared to determine how the distribution of bromide was changing. Although dissolved-bromide concentrations in water from individual wells were variable, the distribution of dissolved bromide did not change substantially during the study period. The time of peak dissolved-bromide concentrations in water from shallow wells downgradient from the landfill was used to estimate a rate of horizontal flow of water in the unconfined aquifer. The average rate of flow between shallow wells downgradient from the landfill was estimated to be 1.2 feet per day. This rate is within the range of values for ground-water flow calculated according to Darcy's law.

Indiana↗

The U.S. Geological Survey Federal-State Cooperative Water-Resources Program, fiscal year 1986

The U.S. Geological Survey 's Federal-State Cooperative Water Resources Program has been in operation for 91 years as of fiscal year (FY) 1986. Hydrologic data collection and interpretive investigations are underway in every State, Puerto Rico, and several territories in cooperation with more than 900 State, regional and local agencies. Federal funds amounted to $49.8 million in this 50-50 matching activity. Total funding was about $106 million, which included $6.9 million furnished by cooperating agencies on an unmatched basis. The Cooperative Program comprised more than 40% of the overall FY 1986 budget of the Survey 's Water Resources Division. The areas of principal emphasis during the year included groundwater contamination, stream quality, water supply and demand, and hydrologic hazards. Information is presented on program priorities and investigations implemented under the merit proposal process. The status of water use information activities, which are being carried out in 48 states and Puerto Rico is reviewed briefly. Standard methods for collecting the data are being developed. Each state has a computerized State Water-Use Data System for storage and retrieval of water-use data for individual users or facilities. (Lantz-PTT)

Open-File Report↗

Fresh and saline ground-water zones in the Punjab region, West Pakistan

An extensive program of test drilling and water sampling, undertaken by the Water and Soils Investigation Division (WASID) of the West Pakistan Water and Power Development Authority (WAPDA) to evaluate hydrologic problems related to waterlogging and soil salinity, has furnished data for the delineation of fresh and saline ground-water zones in the Punjab region of West Pakistan. Fresh ground water containing generally less than 500 ppm (parts per million) of total dissolved solids is found in wide belts paralleling the major rivers and in other areas of ground-water recharge. The fresh groundwater zone of upper (northeastern) Rechna Doab, where annual precipitation in places exceeds 30 inches, is the most extensive of the Punjab region and attains a depth of 1,700 feet or more below land surface near Gujranwala. Fresh ground water adjacent to the Indus River extends locally to depths of about l,500 feet. Saline ground water occurs downgradient from sources of recharge, particularly in the central parts of the interfluvial areas. Also, available data indicate a gradual increase in mineralization with depth and distance from sources of fresh-water recharge. Thus, even extensive fresh-water zones appear to be underlain, at variable depths, by saline ground water in most of the Punjab region. The saline ground waters of the Punjab region do not constitute, however, a distinct salt-water body that can be defined in terms of stratigraphic position, sea-level datum, particular lithology, or by chemical character. The ground waters of the Punjab region are characterized by a gradation from calcium magnesium bicarbonate types, near the sources of recharge, to waters containing a dominant proportion of sodium. Water containing from 500 to 1,000 ppm is commonly of the sodium bicarbonate type, or it may be of the mixed type, having about equal proportions of the common anions (bicarbonate, chloride, and sulfate). With increasing mineralization from about 1,000 to 3,000 ppm, ,the relative proportion of chloride and sulfate increases, and these waters are generally of the sodium chloride or sodium sulfate type. The highly mineralized waters of the Punjab region are generally of the sodium chloride type, whereas in Dera Ismail (D.I.) Khan District sodium sulfate waters predominate. The ground waters from more than 900 sampling sites have been classified into eight types, according to dominant cations and anions. These types have been further subdivided into groups containing different amounts of total dissolved solids. The pattern of distribution of saline ground-water zones in the Punjab region and the observed gradual increase in mineral content, downgradient from sources of fresh-water recharge, can be explained best by the processes of evaporation from the water table and solution of minerals within the alluvial aquifer.

Water Supply Paper↗

Surface-water quality in the West Branch Susquehanna River basin, Pennsylvania: An appraisal of areal and temporal variability from 1962 to 1982 in hydrologic accounting unit 020502

The West Branch Susquehanna River basin has a drainage area of 6,955 square miles in north-central Pennsylvania and comprises Hydrologic Accounting Unit 020502. A National Stream Quality Accounting Network (NASQAN) waterquality data collection site, maintained by the U.S. Geological Survey, is located on the river near its mouth at Lewisburg, Pennsylvania. Water-quality data are collected at numerous other sites throughout the basin by the Pennsylvania Department of Environmental Resources, Bureau of Water Quality Management. Data collected from the NASQAN site and the sites operated by the Pennsylvania Department of Environmental Resources from 1962 to 1982 were used to evaluate water-quality variability in the basin. The following objectives were addressed: (1) describe the surface-water quality upstream of the NASQAN site on an areal and temporal basis; (2) relate the water-quality variability, on both an areal and temporal basis, to general basin characteristics; and (3) assess the ability of the water-quality data collected at the NASQAN site to represent, on both an areal and temporal basis the water quality for Hydrologic Accounting Unit 020502 upstream from the site. Areally, the water quality varies considerably throughout the basin. Generally, the river was found to have moderately good water quality in the upper reaches, poor water quality in its middle reach, and good water quality near the mouth. Two tributaries, Moshannon Creek (median pH 3.9) and Bald Eagle Creek (median pH 7.8), had the most pronounced effect on the water quality of the river. Temporal trends were found in the concentrations of several of the constituents at most of the stations. Of the constituents analyzed, those which exhibited increasing or decreasing trends most frequently were pH, alkalinity, dissolved sulfate, total ammonia, and total nitrite plus nitrate. The largest trends were in the concentrations of total-recoverable aluminum, manganese, and zinc. Causes of areal variation were attributed to land use and geologic variations throughout the basin. Trends which indicated an improvement in water qualijty are believed to be caused by improvements in the treatment of acid mine drainage and wastewater. Trends which indicated degradation of water quality were generally found in areas where these types of treatment are not yet effective. The NASQAN site at Lewisburg was shown not to represent the water quality of the entire basin, either areally or temporally. It does, however, represent the water quality of the West Branch Susquehanna River at its mouth.

Pennsylvania↗

Application of near-surface geophysics as part of a hydrologic study of a subsurface drip irrigation system along the Powder River floodplain near Arvada, Wyoming

Rapid development of coalbed natural gas (CBNG) production in the Powder River Basin (PRB) of Wyoming has occurred since 1997. National attention related to CBNG development has focused on produced water management, which is the single largest cost for on-shore domestic producers. Low-cost treatment technologies allow operators to reduce their disposal costs, provide treated water for beneficial use, and stimulate oil and gas production by small operators. Subsurface drip irrigation (SDI) systems are one potential treatment option that allows for increased CBNG production by providing a beneficial use for the produced water in farmland irrigation. Water management practices in the development of CBNG in Wyoming have been aided by integrated geophysical, geochemical, and hydrologic studies of both the disposal and utilization of water. The U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) and the U.S. Geological Survey (USGS) have utilized multi-frequency airborne, ground, and borehole electromagnetic (EM) and ground resistivity methods to characterize the near-surface hydrogeology in areas of produced water disposal. These surveys provide near-surface EM data that can be compared with results of previous surveys to monitor changes in soils and local hydrology over time as the produced water is discharged through SDI. The focus of this investigation is the Headgate Draw SDI site, situated adjacent to the Powder River near the confluence of a major tributary, Crazy Woman Creek, in Johnson County, Wyoming. The SDI system was installed during the summer of 2008 and began operation in October of 2008. Ground, borehole, and helicopter electromagnetic (HEM) conductivity surveys were conducted at the site prior to the installation of the SDI system. After the installation of the subsurface drip irrigation system, ground EM surveys have been performed quarterly (weather permitting). The geophysical surveys map the heterogeneity of the near-surface geology and hydrology of the study area. The geophysical data are consistent between surveys using different techniques and between surveys carried out at different times from 2007 through 2011. This paper summarizes geophysical results from the 4-year monitoring study of the SDI system.

Wyoming↗

Climate and human water use diminish wetland networks supporting continental waterbird migration

Migrating waterbirds moving between upper and lower latitudinal breeding and wintering grounds rely on a limited network of endorheic lakes and wetlands when crossing arid continental interiors. Recent drying of global endorheic water stores raises concerns over deteriorating migratory pathways, yet few studies have considered these effects at the scale of continental flyways. Here, we investigate the resiliency of waterbird migration networks across western North America by reconstructing long-term patterns (1984–2018) of terminal lake and wetland surface water area in 26 endorheic watersheds. Findings were partitioned regionally by snowmelt- and monsoon-driven hydrologies and combined with climate and human water-use data to determine their importance in predicting surface water trends. Nonlinear patterns of lake and wetland drying were apparent along latitudinal flyway gradients. Pervasive surface water declines were prevalent in northern snowmelt watersheds (lakes −27%, wetlands −47%) while largely stable in monsoonal watersheds to the south (lakes −13%, wetlands +8%). Monsoonal watersheds represented a smaller proportion of total lake and wetland area, but their distribution and frequency of change within highly arid regions of the continental flyway increased their value to migratory waterbirds. Irrigated agriculture and increasing evaporative demands were the most important drivers of surface water declines. Underlying agricultural and wetland relationships however were more complex. Approximately 7% of irrigated lands linked to flood irrigation and water storage practices supported 61% of all wetland inundation in snowmelt watersheds. In monsoonal watersheds, small earthen dams, meant to capture surface runoff for livestock watering, were a major component of wetland resources (67%) that supported networks of isolated wetlands surrounding endorheic lakes. Ecological trends and human impacts identified herein underscore the importance of assessing flyway-scale change as our model depictions likely reflect new and emerging bottlenecks to continental migration.

Global Change Biology↗

Selected hydrologic data, Chester County, Pennsylvania

This report presents selected hydrologic data collected during a study of the ground-water resources of Chester County, Pennsylvania. The study was made during 1973-76 by the U. S. Geological Survey in cooperation with the Chester County Water Resources Authority. This report is intended to make the data conveniently available and to supplement an interpretive report that will be published separately.

Pennsylvania↗

Collection, storage, retrieval, and publication of water-resources data

This publication represents a series of papers devoted to the subject of collection, storage, retrieval, and publication of hydrologic data. The papers were presented by members of the U.S. Geological Survey at the International Seminar on Organization and Operation of Hydrologic Services, Ottawa, Canada, July 15-16, 1976, sponsored by the World Meteorological Organization. The first paper, ' Standardization of Hydrologic Measurements, ' by George F. Smoot discusses the need for standardization of the methods and instruments used in measuring hydrologic data. The second paper, ' Use of Earth Satellites for Automation of Hydrologic Data Collection, ' by Richard W. Paulson discusses the use of inexpensive battery-operated radios to transmit realtime hydrologic data to earth satellites and back to ground receiving stations for computer processing. The third paper, ' Operation Hydrometeorological Data-Collection System for the Columbia River, ' by Nicholas A. Kallio discusses the operation of a complex water-management system for a large river basin utilizing the latest automatic telemetry and processing devices. The fourth paper, ' Storage and Retrieval of Water-Resources Data, ' by Charles R. Showen discusses the U.S. Geological Survey 's National Water Data Storage and Retrieval System (WATSTORE) and its use in processing water resources data. The final paper, ' Publication of Water Resources Data, ' by S. M. Lang and C. B. Ham discusses the requirement for publication of water-resources data to meet the needs of a widespread audience and for archival purposes. (See W78-09324 thru W78-09328) (Woodard-USGS)

Circular↗

Chester County ground-water atlas, Chester County, Pennsylvania

Chester County encompasses 760 square miles in southeastern Pennsylvania. Groundwater-quality studies have been conducted in the county over several decades to address specific hydrologic issues. This report compiles and describes water-quality data collected during studies conducted mostly after 1990 and summarizes the data in a county-wide perspective. In this report, water-quality constituents are described in regard to what they are, why the constituents are important, and where constituent concentrations vary relative to geology or land use. Water-quality constituents are grouped into logical units to aid presentation: water-quality constituents measured in the field (pH, alkalinity, specific conductance, and dissolved oxygen), common ions, metals, radionuclides, bacteria, nutrients, pesticides, and volatile organic compounds. Water-quality constituents measured in the field, common ions (except chloride), metals, and radionuclides are discussed relative to geology. Bacteria, nutrients, pesticides, and volatile organic compounds are discussed relative to land use. If the U.S. Environmental Protection Agency (USEPA) or Chester County Health Department has drinking water standards for a constituent, the standards are included. Tables and maps are included to assist Chester County residents in understanding the water-quality constituents and their distribution in the county. Ground water in Chester County generally is of good quality and is mostly acidic except in the carbonate rocks and serpentinite, where it is neutral to strongly basic. Calcium carbonate and magnesium carbonate are major constituents of these rocks. Both compounds have high solubility, and, as such, both are major contributors to elevated pH, alkalinity, specific conductance, and the common ions. Elevated pH and alkalinity in carbonate rocks and serpentinite can indicate a potential for scaling in water heaters and household plumbing. Low pH and low alkalinity in the schist, quartzite, and gneiss rocks can indicate a potential for corrosive water. The only constituent measured in the field that has a USEPA Secondary Maximum Contaminant Level (SMCL) is pH. The SMCL for pH is 6.5-8.5; 64 percent of samples analyzed for pH were acidic (below pH 6.5). Only 1 percent of samples were basic (above pH 8.5). Of the common ions, the USEPA has SMCLs for chloride, sulfate, and total dissolved solids. The USEPA has a SMCL and a Primary Maximum Contaminant Level (PMCL) for fluoride. Chloride is more closely related to land use than geology. In Chester County, chloride exceeded the SMCL (250 mg/L) only in 5 percent of the services (commercial services, community services, and military) land-use areas. No samples analyzed for sulfate exceeded the SMCL (250 mg/L). Only 3 percent of samples analyzed for total dissolved solids exceeded the SMCL (500 milligrams per liter) (mg/L). No samples analyzed for fluoride equaled or exceeded the SMCL (2.0 mg/L) or PMCL (4.0 mg/L). Iron concentrations exceeded the USEPA SMCL in 11 percent of samples and were highest in schist (14 percent) and gneiss (13 percent). Manganese concentrations exceeded the SMCL in 19 percent of samples and were highest in quartzite and schist (both 28 percent). Lead and arsenic were present in low concentrations: the highest concentrations of lead occurred in water from quartzite (8 percent exceeded the USEPA Action Level), and arsenic was detected mostly in Triassic sedimentary rocks (9 percent exceeded the USEPA PMCL). The highest concentrations of copper occurred more frequently in quartzite rocks, and to a lesser extent were evenly distributed between ground water in gneiss, schist, and Triassic sedimentary rocks. Elevated concentrations of radon-222 and the combined radium-226/radium-228 radionuclides were common in water from quartzite and schist. Gross alpha and gross beta particle activities were elevated in water from quartzite and carbonate rocks. In contrast, elevated concentrations of uranium primarily were measured in water from Triassic sedimentary and carbonate rocks. Despite a sampling bias towards agricultural land use, only two samples indicated the presence of fecal coliforms. Samples analyzed for nutrients generally exhibited low concentrations, but about 11 percent of samples collected for nitrate exceeded the USEPA PMCL. Only one nitrite sample (less than 1 percent) exceeded the respective USEPA PMCL. Approximately 190 samples were collected for each of the three pesticides in this report: lindane, dieldrin, and diazinon. Sampling was biased towards agricultural, low-medium density residential, and wooded land uses. Approximately 95 percent of samples for each pesticide were below minimum reporting levels (MRL). Only lindane has a USEPA PMCL, and only one sample exceeded the standard. Results for dieldrin and diazinon were similar, except results for two diazinon samples where concentrations were 57.0 and 490 micrograms per liter (μg/L). Volatile organic compounds in this report were analyzed in water from 198 samples. Sampling was biased towards agricultural, low-medium density residential, and wooded land uses. Two percent of samples analyzed for trichloroethylene and less than 1 percent of samples analyzed for tetrachloroethylene exceeded their respective USEPA PMCLs (each 5.0 μg/L). No samples analyzed for 1,1,1-trichloroethane exceeded the USEPA PMCL (200 μg/L). No samples analyzed for methyl tert-butyl ether exceeded the USEPA Drinking Water Advisory (20μg/L).

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