USGS Science⌕ Search

SEARCH · USGS Science

Results for “Urban Studies”

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 541 records · Page 30Linked to original sources
USGS2022

Characteristics of day-roosts used by the Northern Long-eared Bat (Myotis septentrionalis) in coastal New York

In North America, Myotis septentrionalis (Northern Long-eared Bat) has experienced precipitous declines from white-nose syndrome. As these bats become rare and difficult to capture, additional day-roost assessments to inform management may fill gaps in our understanding, particularly in habitats and regions where such roosts have never been surveyed. Over 2 summers, we radio-tracked 16 individuals from a maternity colony on Long Island, NY, in a small forested patch surrounded by development and ocean. These bats disproportionately selected small, suppressed Robinia pseudoacacia (Black Locust) trees or snags for roosting. Generally, roosts occurred within the interior or edges of this forest patch, rather than surrounding suburbia, reinforcing the hypothesis that Northern Long-eared Bats are forest adapted. Our study shows even small tracts of forest in coastal, urban areas may have conservation value in providing day-roost and foraging habitat.

New York↗
USGS2022

Pennsylvania and Landsat

The Commonwealth of Pennsylvania straddles an array of landscapes. From east to west, its 46,055 square miles connect the sea-level lowlands of the Atlantic seaboard with the rolling hills of the Midwest. It also acts as a bridge between regions from north to south, with the Appalachian Mountains swooping through its center from its northern border with New York to its southern borders with Maryland and West Virginia. The Declaration of Independence and U.S. Constitution were signed in the Commonwealth’s largest city, Philadelphia, and it was the second of the original 13 colonies to ratify the Constitution. The pivotal Civil War battle of Gettysburg took place in the southern part of Pennsylvania. Western Pennsylvania was an early hub for the coal, oil, and steel industries that fueled the Nation’s growth in the 20th century and still factor into Pennsylvania’s economy. The varied natural features of Pennsylvania have been an important proving ground for the value of satellite imagery from the USGS Landsat Program. Scientists began to lean on Landsat observations early in the program’s history to map the effect of invasive moths on Commonwealth forests. That activity continues to this day. Space-based imagery has also contributed to the study and management of land change from energy development, urban growth, and shifting land use patterns. The Landsat Program’s unparalleled 50-year archive of repeat Earth observations remains a critical public resource for Pennsylvania as environmental changes and land use patterns present new challenges to land managers and urban planners in the Keystone State.

Pennsylvania↗
USGS2011

Characterizing the size distribution of particles in urban stormwater by use of fixed-point sample-collection methods

The U.S Geological Survey, in cooperation with the Wisconsin Department of Natural Resources (WDNR) and in collaboration with the Root River Municipal Stormwater Permit Group monitored eight urban source areas representing six types of source areas in or near Madison, Wis. in an effort to improve characterization of particle-size distributions in urban stormwater by use of fixed-point sample collection methods. The types of source areas were parking lot, feeder street, collector street, arterial street, rooftop, and mixed use. This information can then be used by environmental managers and engineers when selecting the most appropriate control devices for the removal of solids from urban stormwater. Mixed-use and parking-lot study areas had the lowest median particle sizes (42 and 54 (u or mu)m, respectively), followed by the collector street study area (70 (u or mu)m). Both arterial street and institutional roof study areas had similar median particle sizes of approximately 95 (u or mu)m. Finally, the feeder street study area showed the largest median particle size of nearly 200 (u or mu)m. Median particle sizes measured as part of this study were somewhat comparable to those reported in previous studies from similar source areas. The majority of particle mass in four out of six source areas was silt and clay particles that are less than 32 (u or mu)m in size. Distributions of particles ranging from <2 to >500 (u or mu)m were highly variable both within and between source areas. Results of this study suggest substantial variability in data can inhibit the development of a single particle-size distribution that is representative of stormwater runoff generated from a single source area or land use. Continued development of improved sample collection methods, such as the depth-integrated sample arm, may reduce variability in particle-size distributions by mitigating the effect of sediment bias inherent with a fixed-point sampler.

Open-File Report↗
USGS1985

Runoff characteristics and washoff loads from rainfall-simulation experiments on a street surface and a native pasture in the Denver metropolitan area, Colorado

Rainfall-runoff simulation studies were conducted in conjunction with the Denver Regional Urban Runoff Program to: (1) Compare runoff characteristics from two different intensities of simulated rainfall on street-surface plots, (2) document a first flush of constituent washoff loads in runoff from 1,000-sq-ft street-surface plots, (3) compare runoff characteristics from the street surface plots with those from a 69-acre urban mixed land use subjected to natural rainfall, (4) perform statistical analysis of washoff loads, and (5) compare quantity and quality of runoff from 400-sq-ft plots of native pasture subjected to simulated rainfall and from a 405-acre basin of native pasture subjected to natural rainfall. Experiments on the street surface showed that higher intensity simulated rainfall produced a higher percentage of runoff than lower intensity rainfall, and a first flush of constituent loads occurred for most constituents. The event mean constituent concentrations in the street-surface runoff from simulated storms were generally much smaller than those in the runoff from an adjacent urban basin. Simulated rainfall in small native pasture plots produced runoff-to-rainfall ratios similar to runoff-to-rainfall ratios from a larger native pasture subject to natural rainfall. (USGS)

Colorado↗
USGS1987

Runoff characteristics and washoff loads from rainfall-simulation experiments on a street surface and a native pasture in the Denver metropolitan area, Colorado

Rainfall simulation studies were conducted in conjunction with the Denver Regional Urban Runoff Program to: (1) Compare runoff quantity and quality from two different intensities of rainfall on impervious plots having identical antecedent conditions, (2) document a first flush of constituent loads in runoff from l,000-square-foot street-surface plots, (3) compare runoff characteristics from a street surface subjected to simulated rainfall with those from a 69-acre urban basin of mixed land use subjected to natural rainfall, (4) perform statistical analysis of constituent loads in the runoff with several independent variables, and (5) compare the quantity and quality of runoff from 400-square-foot plots of native grasses used for pasture and subjected to simulated rainfall with that from a 405-acre basin covered with native grasses used for pasture and subjected to natural rainfall. The rainfall simulations conducted on the street surface showed that higher intensity simulated rainfall produced a higher percentage of runoff than lower intensity rainfall. A first flush of constituent loads occurred for most constituents in the runoff from most rainfall simulations on the street surface; however, a first flush did not occur in the runoff from simulated rainfall on the pasture. The event mean concentrations of constituents in the runoff from simulated storms on the street surface were generally much smaller than the event mean concentrations of constituents in the runoff from an adjacent urban basin. Analysis of the data from the rainfall simulations on a street surface indicates that intensity of rainfall and total rainfall are important variables determining constituent loads. The design of the experiment was such that intensity of rainfall and total rainfall were highly correlated, thus precluding the development of useful regression equations to predict washoff loads. The quality of runoff from the simulated rainfall on the pasture was influenced by the disturbed perimeters of the plots; however, the runoff-to-rainfall ratios for the simulated storms fell within the range of ratios measured for natural storms over the adjacent 405-acre basin.

Professional Paper↗
USGS1971

Hydrology of two small river basins in Pennsylvania before urbanization, with a section on observation of stream fauna

Basic data on water quantity, chemical quality, and suspended sediment are tabulated to record the conditions existing in two basins near Philadelphia, each about 32 square miles in area. The basins in 1970 are agricultural land for the most part, but urban and industrial development is imminent as the Philadelphia metropolitan area expands. Hopefully, as changes caused by urbanization occur in future years, data published herein will be useful as a base for comparison. Pickering Creek basin has a higher population than the upper East Branch Brandywine Creek basin. The two are comparable in discharge characteristics and in shapes and sizes of channels, but the Pickering Creek basin is producing a considerably larger suspended-sediment load. Also the effects of urbanization are discernible in some chemical parameters. During the study, a small subbasin, one-half square mile in area, was converted from agricultural use to an industrial park. This change resulted in a marked increase in sulfates, nitrates, chlorides, and dissolved solids in the streamflow.

Pennsylvania↗
USGS2007

The National Streamflow Statistics Program: A Computer Program for Estimating Streamflow Statistics for Ungaged Sites

The National Streamflow Statistics (NSS) Program is a computer program that should be useful to engineers, hydrologists, and others for planning, management, and design applications. NSS compiles all current U.S. Geological Survey (USGS) regional regression equations for estimating streamflow statistics at ungaged sites in an easy-to-use interface that operates on computers with Microsoft Windows operating systems. NSS expands on the functionality of the USGS National Flood Frequency Program, and replaces it. The regression equations included in NSS are used to transfer streamflow statistics from gaged to ungaged sites through the use of watershed and climatic characteristics as explanatory or predictor variables. Generally, the equations were developed on a statewide or metropolitan-area basis as part of cooperative study programs. Equations are available for estimating rural and urban flood-frequency statistics, such as the 1 00-year flood, for every state, for Puerto Rico, and for the island of Tutuila, American Samoa. Equations are available for estimating other statistics, such as the mean annual flow, monthly mean flows, flow-duration percentiles, and low-flow frequencies (such as the 7-day, 0-year low flow) for less than half of the states. All equations available for estimating streamflow statistics other than flood-frequency statistics assume rural (non-regulated, non-urbanized) conditions. The NSS output provides indicators of the accuracy of the estimated streamflow statistics. The indicators may include any combination of the standard error of estimate, the standard error of prediction, the equivalent years of record, or 90 percent prediction intervals, depending on what was provided by the authors of the equations. The program includes several other features that can be used only for flood-frequency estimation. These include the ability to generate flood-frequency plots, and plots of typical flood hydrographs for selected recurrence intervals, estimates of the probable maximum flood, extrapolation of the 500-year flood when an equation for estimating it is not available, and weighting techniques to improve flood-frequency estimates for gaging stations and ungaged sites on gaged streams. This report describes the regionalization techniques used to develop the equations in NSS and provides guidance on the applicability and limitations of the techniques. The report also includes a users manual and a summary of equations available for estimating basin lagtime, which is needed by the program to generate flood hydrographs. The NSS software and accompanying database, and the documentation for the regression equations included in NSS, are available on the Web at http://water.usgs.gov/software/.

Techniques and Methods↗
USGS1979

Comparison of selected cultural, physical, and water-quality characteristics of lakes in Washington

This report presents comparisons and a graphical overview of the relative magnitude and the regional and statewide distribution of 19 selected cultural, physical, and water-quality characteristics measured in a reconnaissance study of several hundred lakes in Washington. The selected characteristics presented for each lake include types of land use in the lake drainage basin, shoreline residential development, altitude of lake, mean lake depth, nitrogen and phosphorus concentrations in upper and bottom waters, specific conductance, temperature and dissolved-oxygen concentration cf bottom water, Secchi-disc visibility, emersed macrophytes covering shoreline and lake surface, and fecal-coliform bacteria. Statewide, about two-thirds of the lake drainage basins studied have more than half their land in forest. Urban and suburban developments of the basins are highest in the more populated western Washington counties near Puget Sound, whereas most land in the drainage basins of lakes in the Columbia Plateau of eastern Washington is used for agricultural purposes. Statewide, almost one-fourth of the lakes are shallow (mean depth 2.0 meters or less) and only 7 percent of the lakes have mean depths greater than 20 meters. Dissolved-oxygen layering in summer was detected in many lakes throughout the State. The oxygen concentrations in the upper waters of these lakes were typically near saturation, but the bottom waters of many were severely depleted. Statewide, about one-third of the lakes had Secchi-disc readings of 2.0 meters or less, a value often considered characteristic of eutrophic lakes. The poorest water clarity was observed in the Columbia Plateau, where 68 percent of the lakes had Secchi-disc readings of less than 2.0 meters. Statewide, the median concentration of total phosphorus in the upper waters of lakes was 20 micrograms per liter. More than one-third of the lakes in the State had total phosphorus concentrations in their upper waters that exceeded 30 micrograms per liter, a concentration that is often considered characteristic of eutrophic lakes.

Washington↗
USGS1978

Interim report on streamflow, sediment discharge, and water quality in the Calabazas Creek Basin, Santa Clara County, California

Streamflow, sediment-discharge, and water-quality data are being collected in the Calabazas Creek basin, Santa Clara County, Calif., to determine annual water and sediment discharge at base-line conditions that are representative of a basin prior to urbanization. Results of the first 3 years of the study (1973-75) are given in this report. Climatic conditions during this period were representative of a very wet year (1973) and 2 years of above-average rainfall (1974 and 1975). Daily water and sediment discharge were monitored at three primary stations, and periodic measurements were made at five secondary stations during selected storms. Most of the total annual sediment discharge at each station was transported during a few days each year. Maximum daily sediment discharge in a given year ranged from 23 to 62 percent of the annual total. Daily water discharge at the gaging station Calabazas Creek at Rainbow Drive, near Cupertino, ranged from no flow to 3.31 cubic meters per second. Streamflow at this location was significantly augmented during low flow by diversion of water from the South Bay Aqueduct. Annual sediment discharge at Calabazas Creek at Rainbow Drive was 4,900 t in 1974 and 9,570 t in 1975. A large quantity of sediment was trapped in a debris basin at Comer Drive upstream from this station during both years. If this sediment had not been trapped, sediment discharge at the station would have been about 35 percent greater in 1974 and 30 percent greater in 1975. Most of the trapped sediment consists of sand and gravel that would probably have been deposited in the Calabazas Creek channel downstream from the station. (Woodard-USGS)

California↗
USGS1980

Quality of urban runoff, Tecolote Creek drainage area, San Diego County, California

The quality of storm runoff from a 9.2-square-mile urbanized watershed, Tecolote Creek, San Diego County, Calif., was studied during nine storms from September 1976 through May 1977. Specific conductance reached 2,100 micromhos and total residue concentrations reached 2,770 milligrams per liter. The chemical oxygen demand concentration in 95% of the samples exceeded 50 milligrams per liter, a concentration that may be sufficient to cause severe oxygen depletion in areas of the receiving water, Mission Bay. Lead concentrations in all samples exceeded concentrations thought to affect some aquatic organisms. Median total nitrogen and total orthophosphorus concentrations were far in excess of concentrations known to cause nuisance growth of algae in lakes. Fecal coliform bacteria concentrations greatly exceeded recommended levels for primary contact recreation water. Concentrations of pesticides--heptachlor, malathion, chlordane, DDT, diazinon, and dieldrin--frequently exceeded the recommended maximums for marine or freshwater aquatic systems. Total loads of selected constituents are calculated and may be used to estimate the impact of runoff on the receiving water. (USGS)

Water-Resources Investigations Report↗
USGS1999

Estimating the magnitude of peak flows for streams in Maine for selected recurrence intervals

This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Maine for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for a site on a specific stream. Section 1, 'Estimates of peak flows and maximum recorded flows at USGS streamflow-gaging stations,' contains peak-flow estimates and the maximum recorded flows at 98 U.S. Geological Survey (USGS) streamflow-gaging stations. In the development of the peak-flow estimates at gaging stations, a new generalized skew coefficient was calculated for Maine. This single statewide value of 0.029 (with a standard error of prediction of 0.297) is more accurate for Maine than the national skew isoline map in Bulletin 17B of the Interagency Advisory Committee on Water Data. Two techniques are presented to estimate the peak flows for ungaged, unregulated streams in rural drainage basins. These two techniques were developed using generalized least squares regression procedures at 70 USGS gaging stations in Maine and eastern New Hampshire. Section 2, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins,' uses the final explanatory variables of drainage area and basin wetlands. The average standard error of prediction for the 100-year peak flow regression equation in section 2 was 48.6 percent to -32.7 percent. Drainage area was the only explanatory variable used in section 3, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins - Simplified technique.' The average standard error of prediction for the 100-year peak flow regression equation in section 3 was 80.3 percent to -44.5 percent. Section 4 of the report describes techniques for estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins. Section 5, 'Estimating peak flows for ungaged, unregulated streams in urbanized drainage basins,' describes regression equations for use when a drainage basin is urbanized. These urban regression equations come from a previous USGS nationwide study. As stated in section 6, because peak flows on regulated streams are dependent on variable human actions, estimating peak flows at ungaged sites on regulated streams is beyond the scope of this report.

Maine↗
USGS2025

Beavers in the Tualatin River Basin, northwestern Oregon

Growing interest in beaver-assisted restoration in the Tualatin River Basin of northwestern Oregon motivated a series of studies by the U.S. Geological Survey to assess the capacity of the stream network to support beaver dams and to evaluate the effects of beaver dams and ponds on urban streams. This multichapter volume describes the data collection from 2016–17 and the findings of these studies, which were done in partnership with Clean Water Services. Chapter A documents the locations of beaver dams in the Tualatin River Basin and how many beaver dams the stream network could support with existing and improved riparian vegetation. Beaver dam capacity was estimated by modifying existing tools to account for the low gradient of many streams in the Tualatin River Basin. Chapter B describes the effects of beaver dams and ponds on hydrologic and hydraulic responses of storm flows. Hydrologic and hydraulic responses for two urban stream reaches were compared with and without beaver dams and ponds and for a range of streamflow conditions using two-dimensional hydraulic models. Chapter C characterizes the effects of beaver dams and ponds on the transport and deposition of suspended sediment. Continuous turbidity, discrete suspended-sediment samples, and streamflow measurements collected during storms and base-flow periods were used to assess: (1) suspended-sediment loads upstream and downstream from two beaver-affected reaches, and (2) seasonal and longitudinal turbidity patterns. Chapter D describes the effects of beaver dams and ponds on longitudinal, spatial, and seasonal water-quality patterns. Continuous and synoptic water-quality data were collected along urban stream reaches, and net ecosystem production was calculated for two beaver-affected reaches. The findings of these studies illustrate that the effects of beaver dams and ponds on hydrology, hydraulics, suspended-sediment transport and deposition, and water quality are dependent on the characteristics of a stream reach (for example, channel gradient, groundwater exchange, and riparian vegetation) and the characteristics of beaver dams and ponds along that reach. This information can be used to consider the implications of beaver-assisted restoration in the Tualatin River Basin and the effects of beaver dams and ponds in urban streams.

Oregon↗
USGS2010

Groundwater Quality in the Central Eastside San Joaquin Valley, California

The Central Eastside study unit is located in California's San Joaquin Valley. The 1,695 square mile study unit includes three groundwater subbasins: Modesto, Turlock, and Merced (California Department of Water Resources, 2003). The primary water-bearing units consist of discontinuous lenses of gravel, sand, silt, and clay, which are derived largely from the Sierra Nevada Mountains to the east. Public-supply wells provide most of the drinking water supply in the Central Eastside. Consequently, the primary aquifer in the Central Eastside study unit is defined as that part of the aquifer corresponding to the perforated interval of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 350 feet, consist of solid casing from the land surface to a depth of about 100 to 200 feet, and they are perforated below the solid casing. Water quality in the shallower and deeper parts of the aquifer system may differ from that in the primary aquifer. The Central Eastside study unit has hot and dry summers and cool, moist, winters. Average annual rainfall ranges from 11 to 15 inches. The Stanislaus, Tuolumne, and Merced Rivers, with headwaters in the Sierra Nevada Mountains, are the primary streams traversing the study unit. Land use in the study unit is approximately 59 percent (%) agricultural, 34% natural (primarily grassland), and 7% urban. The primary crops are almonds, walnuts, peaches, grapes, grain, corn, and alfalfa. The largest urban areas (2003 population in parentheses) are the cities of Modesto (206,872), Turlock (63,467), and Merced (69,512). Municipal water use accounts for about 5% of the total water use in the Central Eastside study unit, with the remainder used for irrigated agriculture. Groundwater accounts for about 75% of the municipal supply, and surface water accounts for about 25%. Recharge to the groundwater flow system is primarily from percolation of irrigation return, precipitation, seepage from reservoirs and rivers, and urban return (Burow and others, 2004; Phillips and others, 2007). The primary sources of discharge are pumping for irrigation and municipal supply, evaporation from areas with a shallow depth to water, and discharge to streams. Recharge at shallow depths and pumping from wells at greater depths causes downward movement of groundwater in the aquifer in the Central Eastside. This vertical movement of water has the potential to carry chemical constituents from shallow depths to the greater depths where supply wells commonly are perforated.

Fact Sheet↗
USGS2014

Methods for estimating the magnitude and frequency of floods for urban and small, rural streams in Georgia, South Carolina, and North Carolina, 2011

Reliable estimates of the magnitude and frequency of floods are essential for the design of transportation and water-conveyance structures, flood-insurance studies, and flood-plain management. Such estimates are particularly important in densely populated urban areas. In order to increase the number of streamflow-gaging stations (streamgages) available for analysis, expand the geographical coverage that would allow for application of regional regression equations across State boundaries, and build on a previous flood-frequency investigation of rural U.S Geological Survey streamgages in the Southeast United States, a multistate approach was used to update methods for determining the magnitude and frequency of floods in urban and small, rural streams that are not substantially affected by regulation or tidal fluctuations in Georgia, South Carolina, and North Carolina. The at-site flood-frequency analysis of annual peak-flow data for urban and small, rural streams (through September 30, 2011) included 116 urban streamgages and 32 small, rural streamgages, defined in this report as basins draining less than 1 square mile. The regional regression analysis included annual peak-flow data from an additional 338 rural streamgages previously included in U.S. Geological Survey flood-frequency reports and 2 additional rural streamgages in North Carolina that were not included in the previous Southeast rural flood-frequency investigation for a total of 488 streamgages included in the urban and small, rural regression analysis. The at-site flood-frequency analyses for the urban and small, rural streamgages included the expected moments algorithm, which is a modification of the Bulletin 17B log-Pearson type III method for fitting the statistical distribution to the logarithms of the annual peak flows. Where applicable, the flood-frequency analysis also included low-outlier and historic information. Additionally, the application of a generalized Grubbs-Becks test allowed for the detection of multiple potentially influential low outliers. Streamgage basin characteristics were determined using geographical information system techniques. Initial ordinary least squares regression simulations reduced the number of basin characteristics on the basis of such factors as statistical significance, coefficient of determination, Mallow’s Cp statistic, and ease of measurement of the explanatory variable. Application of generalized least squares regression techniques produced final predictive (regression) equations for estimating the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probability flows for urban and small, rural ungaged basins for three hydrologic regions (HR1, Piedmont–Ridge and Valley; HR3, Sand Hills; and HR4, Coastal Plain), which previously had been defined from exploratory regression analysis in the Southeast rural flood-frequency investigation. Because of the limited availability of urban streamgages in the Coastal Plain of Georgia, South Carolina, and North Carolina, additional urban streamgages in Florida and New Jersey were used in the regression analysis for this region. Including the urban streamgages in New Jersey allowed for the expansion of the applicability of the predictive equations in the Coastal Plain from 3.5 to 53.5 square miles. Average standard error of prediction for the predictive equations, which is a measure of the average accuracy of the regression equations when predicting flood estimates for ungaged sites, range from 25.0 percent for the 10-percent annual exceedance probability regression equation for the Piedmont–Ridge and Valley region to 73.3 percent for the 0.2-percent annual exceedance probability regression equation for the Sand Hills region.

Georgia, North Carolina, South Carolina↗
USGS2020

Protecting the wildland-urban interface in California: Greenbelts vs thinning for wildfire threats to homes

This study utilized native chaparral and sage scrub shrubs to evaluate the impact of light summer irrigation on live fuel moisture content (LFMC) and predicted fire behavior. As to be expected LFMC varied markedly throughout the year being over 100% in winter in all species and treatments but differed markedly by treatment in the summer and fall. For most species lightly irrigated plants had the highest LFMC in the summer and fall, followed by thinned treatments and controls. These differences in moisture content coupled with structural differences in the vegetation contributed to expected differences in flame length and rate of spread. Lightly irrigated native shrubs planted around homes can reduce fire hazard and at the same time increase faunal diversity and other desirable features of utilizing native vegetation.

California↗
USGS2016

Effects of urban land-use on largescale stonerollers in the Mobile River Basin, Birmingham, AL

During the spring and fall of 2001 and the spring of 2002 a study was conducted to evaluate the health of the largescale stoneroller ( Campostoma oligolepis) populations in streams along an urban land-use gradient. Sites were selected from a pool of naturally similar sub-basins (eco-region, basin size, and geology) of the Mobile River basin (MRB), using an index of urban intensity derived from infrastructure, socioeconomic, and land-use data. This urban land-use gradient (ULUG) is a multimetric indicator of urban intensity, ranging from 0 (background) to 100 (intense urbanization). Campostoma sp. have been used previously as indicators of stream health and are common species found in all sites within the MRB. Endpoints used to determine the effects of urban land-use on the largescale stoneroller included total glutathione, histology, hepatic apoptosis, condition factor and external lesions. Liver glutathione levels were positively associated with increasing urban land-use (r 2 = 0.94). Histopathological examination determined that some abnormalities and lesions were correlated with the ULUG and generally increased in prevalence or severity with increasing urbanization. Liver macrophage aggregates were positively correlated to the ULUG. The occurrence of nucleosomal ladders (indicating apoptotic cell death) did not correspond with urban intensity in a linear fashion. Apoptosis, as well as prevalence and severity of a myxozoan parasite, appeared to have a hormetic dose–response relationship. The majority of the biomarkers suggested fish health was compromised in areas where the ULUG ≥ 36.

Alabama↗
USGS2012

Quality of water from crystalline rock aquifers in New England, New Jersey, and New York, 1995-2007

Crystalline bedrock aquifers in New England and parts of New Jersey and New York (NECR aquifers) are a major source of drinking water. Because the quality of water in these aquifers is highly variable, the U.S. Geological Survey (USGS) statistically analyzed chemical data on samples of untreated groundwater collected from 117 domestic bedrock wells in New England, New York, and New Jersey, and from 4,775 public-supply bedrock wells in New England to characterize the quality of the groundwater. The domestic-well data were from samples collected by the USGS National Water-Quality Assessment (NAWQA) Program from 1995 through 2007. The public-supply-well data were from samples collected for the U.S. Environmental Protection Agency (USEPA) Safe Drinking Water Act (SDWA) Program from 1997 through 2007. Chemical data compiled from the domestic wells include pH, specific conductance, dissolved oxygen, alkalinity, and turbidity; 6 nitrogen and phosphorus compounds, 14 major ions, 23 trace elements, 222 radon gas (radon), 48 pesticide compounds, and 82 volatile organic compounds (VOCs). Additional samples were collected from the domestic wells for the analysis of gross alpha- and gross beta-particle radioactivity, radium isotopes, chlorofluorocarbon isotopes, and the dissolved gases methane, carbon dioxide, nitrogen, and argon. Chemical data compiled from the public-supply wells include pH, specific conductance, nitrate, iron, manganese, sodium, chloride, fluoride, arsenic, uranium, radon, combined radium ( 226 radium plus 228 radium), gross alpha-particle radioactivity, and methyl tert -butyl ether (M t BE). Patterns in fluoride, arsenic, uranium, and radon distributions were discernable when the data were compared to lithology groupings of the bedrock, indicating that the type of bedrock has an effect on the quality of groundwater from NECR aquifers. Fluoride concentrations were significantly higher in groundwater samples from the alkali granite, peraluminous granite, and metaluminous granite lithology groups than from samples in the other lithology groups. Water samples from 1.4 percent of 2,167 studied wells had fluoride concentrations that were equal to or greater than the maximum contaminant level (MCL) of 4 milligrams per liter (mg/L) and 7.5 percent of the wells had fluoride concentrations that were equal to or greater than the secondary MCL of 2 mg/L. For arsenic, groundwater samples from the calcareous metasedimentary rocks in the New Hampshire-Maine geologic province, peraluminous granite, and pelitic rocks lithology groups had higher concentrations than did samples from the other lithology groups. Water samples from 13.3 percent of 2,054 studied wells had arsenic concentrations that were equal to or greater than the MCL of 10 micrograms per liter (μg/L), about double the national rate of occurrence in community-supply systems and in domestic wells of the United States. Uranium concentrations were significantly higher in groundwater samples from the peraluminous granite, alkali granite, and calcareous metasedimentary rocks in the New Hampshire-Maine geologic province lithology groups than from samples in the other lithology groups. Water samples from 14.2 percent of 556 studied wells had uranium concentrations equal to or greater than the MCL of 30 μg/L. Radon activities were equal to or greater than the proposed MCL of 300 picocuries per liter (pCi/L) in 95 percent of 943 studied wells, and 33 percent of the wells had radon activities were equal to or greater than the proposed alternative maximum contaminant level (AMCL) of 4,000 pCi/L. Radon activities exceeded the proposed AMCL in 20 percent or more of groundwater samples in each of the studied lithology groups with a minimum of 9 samples, but radon activities were significantly higher in groundwater samples from the alkali granite, peraluminous granite, and Narragansett basin metasedimentary rocks lithology groups. Water samples from 3.2 percent of 564 studied wells had combined radium activities equal to or greater than the MCL of 5 pCi/L; however, combined radium activities were not significantly different among the studied lithology groups. Land use and population density also were evaluated to explain patterns in water quality. Concentrations of nitrate, sodium, chloride, and MtBE from the studied wells were significantly greater in areas of high population density (≥50 persons per square kilometer) than in areas of low population density (<50 persons per square kilometer). Concentrations of sodium, chloride, and M t BE from the studied wells were significantly greater in areas classified as developed (urban lands) than in areas classified as undeveloped (forested), agricultural, or mixed (no dominant land use). Nitrate concentrations from the public-supply wells were not significantly different among the four land use categories, but nitrate concentrations from the domestic wells were significantly greater in areas classified as developed than in areas classified as undeveloped, agricultural, or mixed. Chloride to bromide mass ratios in the domestic well samples indicate that the groundwater was probably affected by at least three halogen sources: local precipitation and recharge waters, remnant seawater and connate waters evolved from seawater, and recharge waters affected by road salt. The groundwater in the NECR aquifers generally contained low concentrations of nitrate, VOCs, and pesticides. Less than 1 percent of water samples from 4,781 studied wells had concentrations of nitrate greater than the MCL of 10 mg/L. Less than 1 percent of water samples from 1,299 studied wells exceeded the USEPA advisory level of 20 to 40 μg/L for M t BE. None of the other studied VOCs exceeded a human health benchmark. M t BE (36 percent frequency detection) and chloroform (32.9 percent frequency detection) were the most frequently detected (>0.02 μg/L) VOCs in the domestic wells. M t BE was detected more often in water samples with apparent ages of less than 25 years than in water samples with apparent ages greater than 25 years. This finding is consistent with the time period of high M t BE use in areas in the United States where reformulated gasoline was mandated. The largest pesticide concentration was an estimated concentration of 0.06 μg/L for the herbicide metolachlor. Deethylatrazine, a degradate of atrazine, (18 percent frequency detection) and atrazine (8 percent frequency detection) were the only pesticide compounds detected (>0.001 μg/L) in more than 3 percent of the domestic wells. None of the detected pesticide compounds exceeded human health benchmarks. Concentrations of nitrate and gross alpha-particle activities were significantly greater in the water samples from the domestic wells than in samples from the public-supply wells. Concentrations of sodium, chloride, iron, manganese, and uranium were significantly greater in the water samples from the public-supply wells than in the samples from the domestic wells. One possible explanation may be related to differences in field processing (filtered samples from the domestic wells compared to unfiltered samples from the public-supply wells). The high frequency of detections for a wide variety of manmade and naturally occurring contaminants in both domestic and public-supply wells shows the vulnerability of NECR aquifers to contamination. The highly variable water quality and the association with highly variable lithology of crystalline bedrock underscores the importance of testing individual wells to determine if concentrations for the most commonly detected contaminants exceed human health benchmarks.

Connecticut, Maine, Massachusetts, New Hampshire, ↗
USGS2004

Trace elements and organic compounds in sediment and fish tissue from the Great Salt Lake basins, Utah, Idaho, and Wyoming, 1998-99

A study to determine the occurrence and distribution of trace elements, organochlorine pesticides, polychlorinated biphenyls (PCBs), and semivolatile organic compounds in sediment and in fish tissue was conducted in the Great Salt Lake Basins study unit of the National Water-Quality Assessment (NAWQA) program during 1998-99. Streambed-sediment and fish-tissue samples were collected concurrently at 11 sites and analyzed for trace-element concentration. An additional four sites were sampled for streambed sediment only and one site for fish tissue only. Organic compounds were analyzed from streambed-sediment and fish-tissue samples at 15 sites concurrently. Bed-sediment cores from lakes, reservoirs, and Farmington Bay collected by the NAWQA program in 1998 and by other researchers in 1982 were used to examine historical trends in trace-element concentration and to determine anthropogenic sources of contaminants. Cores collected in 1982 from Mirror Lake, a high-mountain reference location, showed an enrichment of arsenic, cadmium, copper, lead, tin, and zinc in the surface sediments relative to the deeper sediments, indicating that enrichment likely began after about 1900. This enrichment was attributed to atmospheric deposition during the period of metal-ore mining and smelting. A core from Echo Reservoir, in the Weber River Basin, however, showed a different pattern of trace-element concentration that was attributed to a local source. This site is located downstream from the Park City mining district, which is the most likely historical source of trace elements. Cores collected in 1998 from Farmington Bay show that the concentration of lead began to increase after 1842 and peaked during the mid-1980s and has been in decline since. Recent sediments deposited during 1996-98 indicate a 41- to 62-percent reduction since the peak in the mid-1980s. The concentration of trace elements in streambed sediment was greatest at sites that have been affected by historic mining, including sites on Little Cottonwood Creek in the Jordan River basin, Silver Creek in the Weber River basin, and the Weber River below the confluence with Silver Creek. There was significant correlation of lead concentrations in streambed sediment and fish tissue, but other trace elements did not correlate well. Streambed sediment and fish tissue collected from sites in the Bear River basin, which is predominantly rangeland and agriculture, generally had low concentrations of most elements. Sediment-quality guidelines were used to assess the relative toxicity of streambed-sediment sites to aquatic communities. Sites affected by mining exceeded the Probable Effect Concentration (PEC), the concentration at which it is likely there will be a negative effect on the aquatic community, for arsenic, cadmium, copper, lead, silver, mercury, and zinc. Sites that were not affected by mining did not exceed these criteria. Concentrations of trace elements in samples collected from the Great Salt Lake Basins study unit (GRSL) are high compared to those of samples collected nationally with the NAWQA program. Nine of 15 streambed-sediment samples and 11 of 14 fish-tissue samples had concentrations of at least one trace element greater than the concentration of 90 percent of the samples collected nationally during 1993-2000. Organic compounds that were examined in streambed sediment and fish-tissue samples also were examined in bed-sediment cores. A bed-sediment core from Farmington Bay of Great Salt Lake showed an increase in total polycyclic aromatic hydrocarbon (PAH) concentrations coincident with the increase in population in Salt Lake Valley, which drains into this bay. Analysis of streambed-sediment samples showed that the highest concentrations of PAHs were detected at urban sites, including two sites in the lower Jordan River (the Jordan River flows into Farmington Bay), the Weber River at Ogden Bay, and the Provo River near Provo. Other organic compounds detected in streambed sediment in the lower Jordan River were PCBs, DDT compounds, and chlordane compounds. Organic compounds were detected more frequently in fish tissue than in streambed sediment. Chlordane compounds and PCBs were detected more frequently at urban sites. DDT compounds were detected at 13 of 15 sites including urban and agricultural sites. Concentrations of total DDT in fish tissue exceeded the guideline for protection of fish-eating wildlife at two urban sites. The concentration of organic compounds in the GRSL study unit is low compared with that of samples collected nationally.

Idaho, Utah, Wyoming↗