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At least 1,675 records · Page 93Linked to original sources
USGS1977

Hydrologic data for North Creek, Trinity River basin, Texas, 1975

This report contains the rainfall, runoff, and storage data collected during the 1975 water year for the 21.6-square-mile area above the stream-gaging station North Creek near Jacksboro, Texas. The weighted-mean rainfall in the study area during the water year was 39.01 inches, which is greater than the 18-year average of 30.21 inches for the period 1958-75. Monthly rainfall totals ranged from 1.04 inches in November to 7.94 inches in May. The mean discharge for 1975 at the stream-gaging station was 5.98 cfs, compared with the 14-year (1957-70) average of 5.75 cfs. The annual runoff from the basin above the stream-gaging station was 4,330 acre-feet or 3.76 inches. Three storms were selected for detailed computations for the 1975 water year. The storms occurred on Oct. 30-31, 1974, May 2, 1975 , and Aug. 26, 1975. Rainfall and discharge were computed on the basis of a refined time breakdown. Patterns of the storms are illustrated by hydrographs and mass curves. A summary of rainfall-runoff data is tabulated. There are five floodwater-retarding structures in the study area. These structures have a total capacity of 4,425 acre-feet below flood-spillway crests and regulate streamflow from 16.3 square miles, or 75 percent of the study area. A summary of the physical data at each of the floodwater-retarding structures is included. (Woodard-USGS)

Texas↗
USGS2010

Summary and statistical analysis of precipitation and groundwater data for Brunswick County, North Carolina, Water Year 2008

Groundwater conditions in Brunswick County, North Carolina, have been monitored continuously since 2000 through the operation and maintenance of groundwater-level observation wells in the surficial, Castle Hayne, and Peedee aquifers of the North Atlantic Coastal Plain aquifer system. Groundwater-resource conditions for the Brunswick County area were evaluated by relating the normal range (25th to 75th percentile) monthly mean groundwater-level and precipitation data for water years 2001 to 2008 to median monthly mean groundwater levels and monthly sum of daily precipitation for water year 2008. Summaries of precipitation and groundwater conditions for the Brunswick County area and hydrographs and statistics of continuous groundwater levels collected during the 2008 water year are presented in this report. Groundwater levels varied by aquifer and geographic location within Brunswick County, but were influenced by drought conditions and groundwater withdrawals. Water levels were normal in two of the eight observation wells and below normal in the remaining six wells. Seasonal Kendall trend analysis performed on more than 9 years of monthly mean groundwater-level data collected in an observation well located within the Brunswick County well field indicated there is a strong downward trend, with water levels declining at a rate of about 2.2 feet per year.

North Carolina↗
USGS2025

A crosswalk of the 2015 World Terrestrial Ecosystems to the International Union for the Conservation of Nature Global Ecosystem Typology Framework

To support ecosystem mapping and accounting applications, we aligned the 2015 U.S. Geological Survey/Esri/The Nature Conservancy-World Terrestrial Ecosystems (WTEs) with the International Union for Conservation of Nature Global Ecosystem Typology (GET) framework. This process, known as “crosswalking,” enabled the development of a global map of GET level 3 Ecosystem Functional Groups (EFGs) at a 250-meter spatial resolution. Crosswalking involved manually assigning 1,781 biogeographically stratified WTEs to their most probable EFG based on similarities in climate, terrain, vegetation, and geographic distribution. We compared attributes of the WTE dataset with summary characteristics of the EFGs. The resulting crosswalked global map of International Union for Conservation of Nature GET ecosystems is intended to be useful for standardizing ecosystem classification and reporting under frameworks such as the Kunming-Montreal Global Biodiversity Framework and the United Nations System of Environmental-Economic Accounting. We discuss key challenges in reconciling non-identical classifications, such as many-to-one relationships and variation in data quality.

Open-File Report↗
USGS2015

Studies by the U.S. Geological Survey in Alaska, Volume 15

Summary Professional Paper 1814— Studies by the U.S. Geological Survey in Alaska, Volume 15 —continues a long-running series of collected volumes of U.S. Geological Survey (USGS) scientific reports on Alaska. This series presents new and sometimes preliminary findings that are of interest to Earth and biological scientists in academia, government, and industry; to land and resource managers; and to the general public. The series covers a broad spectrum of scientific topics, from various parts of Alaska, serving to emphasize the diversity of USGS efforts to meet the Nation’s needs for Earth-science information in the State. The USGS provides reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

Professional Paper↗
USGS1968

Water data for metropolitan areas: A summary of data from 222 areas in the United States

Expansion of metropolitan areas poses persistent problems in management of the hydrologic environment. Adequate hydrologic data are prerequisite to proper planning and engineering design of urban environments. Some such data are available and are tabulated for each Standard Metropolitan Statistical Area in the United States. Information for each area consists of (1) data on size and population, (2) a short statement of the hydrology of the area, (3) a summary of current data-collection activities in the area, (4) a listing of current U.S. Geological Survey investigational projects in the area, and (5) a short listing of reports relating to the hydrology of the area.

Water Supply Paper↗
USGS1975

A Study of earthquake losses in the Puget Sound, Washington, area

The Puget Sound Basin has a history of frequent seismic activity, including two recent damaging events. The greatest extent of urban development and the most densely populated area generally correspond to the area where the greatest energy release has been experienced. For this study two earthquakes have been simulated, each having magnitude 7.5, a reasonable maximum value for this area. Analysis of the events indicate that under the worst condition as many as 2,200 people would die, and 8,700 additional persons would suffer injuries requiring hospitalization or immediate medical treatment. Such casualties would occur under the worst conditions of exposure, as during the rush hours, but could be approximately as great at any time during the working day. It is possible that as many as 23,500 people would be homeless or would require temporary shelter pending reestablishment or relocation. Conditions of exposure would be altered during the nighttime, causing a drastic reduction in casulaty potentials to a level of about 5-10 percent of the daytime losses. Thus, the time of greatest concern is during the normal working day, and the areas of concern are the highly urbanized sections of the Puget Sound Basin. This study is intended to inform those agencies serving the region of potential hazard to people, structures, and lifeline functions, in such a way that the administrators of emergency services can proceed with confidence in planning response to earthquake disaster. Figure 1 shows the extent of the study area and the location of the epicenters of the postulated earthquakes. A comparison of the two isoseismal maps as they apply to each county, in tables 1 through 6, emphasizes the marked change in intensity at a site as the simulated earthquake is moved from a close to a distant location. The Modified Mercalli Intensity scale is defined on page 284. The report is concerned not only with human casualties and displacement, but also with impairment or destruction of essential facilities critical to the continuing normal functioning of the area. This includes hospitals and medical personnel, police and fire department equipment and personnel, communications, and utilities. The total damage profile was developed with careful consideration of conditions of the seismicity, geological history, population density and distribution, and physical status of structural and lifeline installations throughout the region. There is a potential for broad fluctuation in the casualty figures resulting from the chance positioning of people at the time of the occurrence of the earthquake. An example is that of the Lafayette Elementary School in West Seattle, where, in the 1949 earthquake, a large brick gable over the entry collapsed directly onto an area normally used for assembly of pupils. Such assembly regularly occurred at 11:55 a.m. The earthquake occurred at 11:57 a.m., but fortunately during the spring vacation. Following a large earthquake, effective remedial steps to maintain or to return to operation the essential public services will depend upon the prompt and informed actions of public agencies. Response planning should include not only consideration of disaster problems within a particular jurisdiction but also sharing of assistance with neighboring jurisdictions. Moderate response requirements experienced in one area can free resources to aid communities in more heavily damaged portions of the affected area. The damage profile is quite different among the six counties within the study. The remainder of the summary is devoted to a brief general assessment of possible problems in each of the counties. A detailed development and presentation of each of the problems is covered in the text of the report.

Washington↗
USGS1989

Water-quality data for the Potomac-Raritan-Magothy aquifer system in the northern coast plain of New Jersey, 1923-86

Ground-water-quality data for the upper and middle aquifers of the Potomac-Raritan-Magothy aquifer system in Middlesex and Monmouth Counties are compiled for the period 1923-86. A total of 330 wells were sampled: 192 wells in the upper aquifer and 138 wells in the middle aquifer. Most of the complete water-quality analyses were collected after September 1984, as part of a regional ground-water assessment. Well-construction data for the sampled wells also are presented. Public-supply, domestic-supply, industrial, commercial, irrigation, and observation wells were sampled for the study. Field measurements made at the time of sample collection include water temperature, specific conductance , dissolved oxygen, pH, alkalinity, and bicarbonate concentration. Laboratory determinations include common ions, silica, dissolved solids, trace metals, volatile organic compounds, and pesticides. A quality-assurance program was followed to evaluate and assure the quality of the data. The report also contains a table of lithologic and hydrologic characteristics of the geologic units in the study area, a table of chloride concentrations and field measurements from 1923-86, and statistical summaries of selected water-quality data for the upper and middle aquifers. Many constituents were found in a wide range of concentrations. Water from more than 25 percent of the wells sampled contained lead concentrations above the detection limit of 10 ug/L (micrograms per liter). Included in this number are some wells that had lead concentrations greater than the U.S. Environmental Protection Agency (USEPA) primary drinking-water regulation of 50 ug/L. Cadmium concentrations, although lower than lead concentrations, followed a similar pattern. Water from approximately 25 percent of the wells in the upper aquifer, contain cadmium concentrations equal to or greater than the detection limit of 1 ug/L. Dissolved iron concentrations ranged from 5 ug/L to 480,000 ug/L. Water from more than 50 percent of the wells sampled contained iron concentrations in excess of the USEPA secondary drinking-water recommended limit of 300 ug/L. Chloride concentrations greater than the USEPA secondary drinking-water recommended limit of 250 milligrams per liter were found in samples from wells located in the cities of Perth Amboy and South Amboy; in the boroughs of Keansburg, Sayreville, Keyport, and Union Beach; and in the townships of Old Bridge and Woodbridge. Of 21 samples collected from wells screened in the upper aquifer and analyzed for 30 volatile organic compounds (VOCs), 5 samples contained at least 1 VOC at or above the detection limit. In the middle aquifer, 12 of the 21 samples collected and analyzed for VOCs contained at least 1 VOC greater than the detection limit. Concentrations of pesticides generally were low. Of the 43 samples collected from wells screened in the upper aquifer and analyzed for pesticides, 4 samples contained concentrations of pesticides at or greater than the detection limit. In the middle aquifer, 6 of 38 samples collected and analyzed for 32 pesticides had at least 1 pesticide with a concentration greater than the detection limit.

New Jersey↗
USGS1996

Level II scour analysis for Bridge 25 (CRAFTH00220025) on Town Highway 22, crossing the Wild Branch Lamoille River, Craftsbury, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure CRAFTH00220025 on town highway 22 crossing the Wild Branch Lamoille River, Craftsbury, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level I study is included in Appendix E of this report. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and can be found in Appendix D. The site is in the New England Upland physiographic province of north-central Vermont in the town of Bridgewater. The 9.52-mi 2 drainage area is in a predominantly rural basin with some pasture on the valley bottom. In the vicinity of the study site, the banks have less than 25% woody vegetation coverage. In the study area, the Wild Branch Lamoille River has a meandering channel in a low relief valley setting with wide flood plains and a slope of approximately 0.0044 ft/ft, an average channel top width of 35 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel (D 50 is 38.6 mm or 0.127 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 9, 1994, indicated that the reach was laterally unstable. The town highway 22 crossing of the Wild Branch Lamoille Riveris a 31-ft-long, two-lane bridge consisting of one 29-foot span concrete slab superstructure (Vermont Agency of Transportation, written commun., August 4, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the opening and the opening-skew-to-roadway is 20 degrees. A scour hole 1.5 ft deeper than the mean thalweg depth was observed along the left bank side of the channel upstream during the Level I assessment. There are tall, steep stone fill embankments (artificial levees) that make up both banks between 50 feet upstream and the upstream face of the bridge, which straighten and constrict the channel. Type-2 stone fill (less than 36 inches diameter) is reported on the banks upstream, the upstream wingwalls, the abutments, the downstream left wingwall, and the downstream left bank. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 2.5 ft. The worst-case contraction scour occurred at the incipient overtopping discharge, which was less than the 100-year discharge. Abutment scour ranged from 4.7 to 8.6 ft. The worst-case abutment scour also occurred at the incipient overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Many factors, including historical performance during flood events, the geomorphic assessment, scour protection, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein, based on the consideration of additional contributing factors and experienced engineering judgement.

Vermont↗
USGS2013

Statewide summary for Louisiana: Chapter E in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010

Throughout the past century, emergent wetlands have been declining across the Gulf of Mexico. Emergent wetland ecosystems provide a variety of resources, including plant and wildlife habitat, commercial and recreational economic activity, and natural barriers against storms. As emergent wetland losses increase, so does the need for information on the causes and effects of this loss, emergent wetland mapping, monitoring and restoration efforts, and education. The U.S. Geological Survey and the U.S. Environmental Protection Agency’s Gulf of Mexico Program are committed to restoring, enhancing, and protecting these important ecosystems. The purpose of this report is to provide scientists, managers, and citizens with valuable baseline information on the status and trends of emergent wetlands along the coast of the Gulf of Mexico. This study examines the emergent wetlands of eight individual estuarine areas within the northern Gulf of Mexico region, as well as presenting statewide summaries for Texas, Louisiana, Mississippi, Alabama, and Florida. Each estuarine area is detailed in vignettes that address current status and historical trends of estuarine and palustrine emergent wetlands, emergent wetlands mapping and monitoring, causes of status change, restoration and enhancement activities, background information for the study area, and the methodology employed to analyze and document the historical trends and current status of emergent wetlands. This chapter examines the estuaries of Louisiana.

Louisiana↗
USGS2017

Final synthesis report for factors controlling DDE dechlorination rates on the palos verdes shelf: A field and laboratory investigation

This project was organized into separate field and laboratory studies aimed at answering “18 questions” in the original Scope of Work (cf., section 2 of this report, Background, for explanation). Because of some early results, certain questions became irrelevant and were, therefore, not pursued. In other cases, there simply was not enough time to complete the originally planned studies. On the other hand, additional work, not identified in any of the original “18 questions”, was carried out for purposes of addressing specific issues of concern to the USEPA (United States Environmental Protection Agency). Examples of the latter include: 1) the analysis of an expanded list of sediment cores for DDX (DDX refers to the ten DDT-related compounds of interest in this study; cf., Eganhouse et al., [1]) and selected PCB congeners to facilitate estimation of site-specific reductive dechlorination (RDC) and total loss rates, 2) analysis of gravity and box cores for trace elements to allow stratigraphic alignment, and 3) determination of the extent of mineralization of p,p’-DDE (1-chloro-2-[2,2-dichloro-1-(4- chlorophenyl)ethyl]benzene) in microcosm experiments. In this Executive Summary, we offer a brief recapitulation of what was learned about the factors controlling reductive dechlorination of p,p’-DDE in Palos Verdes Shelf (PVS) sediments using the “18 questions” as a structural guide. The summary is written in narrative form, but references to specific sections (corresponding to the “18 questions”) are identified parenthetically in the text so that the reader can explore the expanded answers that appear later in the report.

Palos Verdes Shelf↗
USGS2009

St. Louis Area Earthquake Hazards Mapping Project - December 2008-June 2009 Progress Report

This report summarizes the mission, the project background, the participants, and the progress of the St. Louis Area Earthquake Hazards Mapping Project (SLAEHMP) for the period from December 2008 through June 2009. During this period, the SLAEHMP held five conference calls and two face-to-face meetings in St. Louis, participated in several earthquake awareness public meetings, held one outreach field trip for the business and government community, collected and compiled new borehole and digital elevation data from partners, and published a project summary.

Open-File Report↗
USGS2017

DOI/GTN-P Climate and active-layer data acquired in the National Petroleum Reserve–Alaska and the Arctic National Wildlife Refuge, 1998–2015

This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2015; this array is part of the Global Terrestrial Network for Permafrost (DOI/GTN-P). In addition to presenting data, this report also describes monitoring, data collection, and quality-control methods. The array of 16 monitoring stations spans lat 68.5°N. to 70.5°N. and long 142.5°W. to 161°W., an area of approximately 150,000 square kilometers. Climate summaries are presented along with quality-controlled data. Data collection is ongoing and includes the following climate- and permafrost-related variables: air temperature, wind speed and direction, ground temperature, soil moisture, snow depth, rainfall totals, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

Alaska↗
USGS2018

DOI/GTN-P climate and active-layer data acquired in the National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge, 1998-2019

This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2019; this array is part of the Global Terrestrial Network for Permafrost (DOI/GTN-P). In addition to presenting data, this report also describes monitoring, data collection, and quality-control methods. The array of 16 monitoring stations spans lat 68.5°N. to 70.5°N. and long 142.5°W. to 161°W., an area of approximately 150,000 square kilometers. Climate summaries are presented along with quality-controlled data. Data collection is ongoing and includes the following climate- and permafrost-related variables: air temperature, wind speed and direction, ground temperature, soil moisture, snow depth, rainfall totals, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

Alaska↗
USGS2014

DOI/GTN-P climate and active-layer data acquired in the National Petroleum Reserve: Alaska and the Arctic National Wildlife Refuge, 1998-2011

This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2011; this array is part of the Global Terrestrial Network for Permafrost, (DOI/GTN-P). In addition to presenting data, this report also describes monitoring, data collection, and quality-control methodology. This array of 16 monitoring stations spans lat 68.5°N. to 70.5°N. and long 142.5°W. to 161°W., an area of approximately 150,000 square kilometers. Climate summaries are presented along with quality-controlled data. Data collection is ongoing and includes the following climate- and permafrost-related variables: air temperature, wind speed and direction, ground temperature and soil moisture, snow depth, rainfall, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

Alaska↗
USGS2014

DOI/GTN-P climate and active-layer data acquired in the National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge

This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2013; this array is part of the Global Terrestrial Network for Permafrost, (DOI/GTN-P). In addition to presenting data, this report also describes monitoring, data collection, and quality-control methods. This array of 16 monitoring stations spans lat 68.5°N. to 70.5°N. and long 142.5°W. to 161°W., an area of approximately 150,000 square kilometers. Climate summaries are presented along with quality-controlled data. Data collection is ongoing and includes the following climate- and permafrost-related variables: air temperature, wind speed and direction, ground temperature, soil moisture, snow depth, rainfall totals, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

Alaska↗
USGS2016

DOI/GTN-P Climate and active-layer data acquired in the National Petroleum Reserve–Alaska and the Arctic National Wildlife Refuge, 1998–2014

This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2014; this array is part of the Global Terrestrial Network for Permafrost (DOI/GTN-P). In addition to presenting data, this report also describes monitoring, data collection, and quality-control methods. The array of 16 monitoring stations spans lat 68.5°N. to 70.5°N. and long 142.5°W. to 161°W., an area of approximately 150,000 square kilometers. Climate summaries are presented along with quality-controlled data. Data collection is ongoing and includes the following climate- and permafrost-related variables: air temperature, wind speed and direction, ground temperature, soil moisture, snow depth, rainfall totals, up- and downwelling shortwave radiation, and atmospheric pressure. These data were collected by the U.S. Geological Survey in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.

Alaska↗
USGS2011

Trace elements and radon in groundwater across the United States, 1992-2003

Trace-element concentrations in groundwater were evaluated for samples collected between 1992 and 2003 from aquifers across the United States as part of the U.S. Geological Survey National Water-Quality Assessment Program. This study describes the first comprehensive analysis of those data by assessing occurrence (concentrations above analytical reporting levels) and by comparing concentrations to human-health benchmarks (HHBs). Data from 5,183 monitoring and drinking-water wells representing more than 40 principal and other aquifers in humid and dry regions and in various land-use settings were used in the analysis. Trace elements measured include aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Tl), uranium (U), vanadium (V), and zinc (Zn). Radon (Rn) gas also was measured and is included in the data analysis. Climate influenced the occurrence and distribution of trace elements in groundwater whereby more trace elements occurred and were found at greater concentrations in wells in drier regions of the United States than in humid regions. In particular, the concentrations of As, Ba, B, Cr, Cu, Mo, Ni, Se, Sr, U, V, and Zn were greater in the drier regions, where processes such as chemical evolution, ion complexation, evaporative concentration, and redox (oxidation-reduction) controls act to varying degrees to mobilize these elements. Al, Co, Fe, Pb, and Mn concentrations in groundwater were greater in humid regions of the United States than in dry regions, partly in response to lower groundwater pH and (or) more frequent anoxic conditions. In groundwater from humid regions, concentrations of Cu, Pb, Rn, and Zn were significantly greater in drinking-water wells than in monitoring wells. Samples from drinking-water wells in dry regions had greater concentrations of As, Ba, Pb, Li, Sr, V, and Zn, than samples from monitoring wells. In humid regions, however, concentrations of most trace elements were greater in monitoring wells than in drinking-water wells; the exceptions were Cu, Pb, Zn, and Rn. Cu, Pb, and Zn are common trace elements in pumps and pipes used in the construction of drinking-water wells, and contamination from these sources may have contributed to their concentrations. Al, Sb, Ba, B, Cr, Co, Fe, Mn, Mo, Ni, Se, Sr, and U concentrations were all greater in monitoring wells than in drinking-water wells in humid regions. Groundwater from wells in agricultural settings had greater concentrations of As, Mo, and U than groundwater from wells in urban settings, possibly owing to greater pH in the agricultural wells. Significantly greater concentrations of B, Cr, Se, Ag, Sr, and V also were found in agricultural wells in dry regions. Groundwater from dry-region urban wells had greater concentrations of Co, Fe, Pb, Li, Mn, and specific conductance than groundwater from agricultural wells. The geologic composition of aquifers and aquifer geochemistry are among the major factors affecting trace-element occurrence. Trace-element concentrations in groundwater were characterized in aquifers from eight major groups based on geologic material, including (1) unconsolidated sand and gravel; (2) glacial unconsolidated sand and gravel; (3) semiconsolidated sand; (4) sandstone; (5) sandstone and carbonate rock; (6) carbonate rock; (7) basaltic and other volcanic rock; and (8) crystalline rock. The majority of groundwater samples and the largest percentages of exceedences of HHBs were in the glacial and nonglacial unconsolidated sand and gravel aquifers; in these aquifers, As, Mn, and U are the most common trace elements exceeding HHBs. Overall, 19 percent of wells (962 of 5,097) exceeded an HHB for at least one trace element. The trace elements with HHBs included in this summary were Sb, As, Ba, Be, B, Cd, Cr,

Scientific Investigations Report↗
USGS1995

National Research Program of the U.S. Geological Survey, Water Resources Division fiscal year 1994

This report provides current information about the National Research Program (NRP) of the U.S. Geological Survey's Water Resources Division (WRD) during fiscal year 1994. Organized by NRP's six research disciplines ecology, geomorphology and sediment transport, ground-water chemistry, ground-water hydrology, surface-water chemistry, and surface-water hydrology the volume contains a summary of the problem, objective, approach, and progress for each project that was active during fiscal year 1994. It also contains bibliographic information that, because of the long-term nature of the program, covers a 5-year period.

Open-File Report↗