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Nitrification and nitrate reduction were examined in an ephemeral drainage channel receiving discharge from coalbed natural gas (CBNG) production wells in the Powder River Basin, Wyoming. CBNG co-produced water typically contains dissolved inorganic nitrogen (DIN), primarily as ammonium. In this study, a substantial portion of discharged ammonium was oxidized within 50 m of downstream transport, but speciation was markedly influenced by diel fluctuations in dissolved oxygen (> 300 µM). After 300 m of transport, 60% of the initial DIN load had been removed. The effect of benthic nitrogen-cycling processes on stream water chemistry was assessed at 2 locations within the stream channel using acrylic chambers to conduct...
A 1.6 ha plot of Atriplex canescens (fourwing saltbush) was established in a desert soil at a former uranium ore-processing plant, near Monument Valley, Arizona, to remediate nitrate and ammonium N contamination. The plants were irrigated to stimulate growth and N uptake. However, NO3? loss from the soil was unexpectedly rapid. Initially, the soil contained approximately 180 mg kg?1 NO3??N distributed at depths up to 4.6 m, but concentrations decreased to 80 mg kg?1 after 41 months. Losses occurred throughout the plot at all soil depths. NH4?N remained unchanged (ca.180 mg kg?1). Soil moisture was generally below field capacity and soil?water flux showed no net downward movement over the course of the study. A salt...
Nitrogen translocation was measured in Cladonia portentosa during 2 yr growth in Scottish heathland. Translocation was predicted to occur if N is resorbed from senescent basal tissue and recycled within the thallus. (15)N was introduced into either the lower (TU thalli) or upper (TD thalli) 25 mm of 50-mm-long thalli as (15)N-NH(4) (+), (15)N-NO(3) (-) or (15)N-glycine. Labelled thalli were placed within intact lichen cushions, either upright (TU) or inverted (TD). Vertical distribution of label was quantified immediately following labelling and after 1 and 2 yr. Independently of the form of introduced label, (15)N migrated upwards in TU thalli, with new growth being a strong sink. Sink regions for (15)N during...
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The dataset presents 5- or 15-minute data for turbidity and Fluorescent Dissolved Organic Matter (FDOM) measured by in-stream sensors at the USGS gage Río Icacos near Naguabo (50075000), Luquillo Experimental Forest, Puerto Rico. The measurement period was 10 March, 2017 to 1 March, 2019. The USGS sensors were co-located with sensors for nitrate and specific conductance operated by University of New Hampshire (UNH), and these datasets are all used in the accompanying publication. A 4-month gap in turbidity in 2018 was mostly filled by UNH data, using a relation between USGS turbidity and co-located UNH turbidity when both sensors were operating. The main metric used in the journal paper was the ratio of coefficient...
Mitigating Gulf of Mexico hypoxia will require practices to reduce nitrate losses from tile drainage throughout the upper Mississippi River basin. Wetlands are a key practice to accomplish this via denitrification, but locations of feasible wetland sites will need to be determined on a watershed specific basis. This study's objective was to demonstrate that LiDAR topographic data can be used to identify feasible wetland locations in a 6500 ha watershed in northern Illinois, and then estimate the impact on watershed nitrate loads from wetlands hypothetically constructed at those locations. The evaluation resulted in the identification of eleven sites where wetlands could intercept tile drainage from 30% of the watershed....
This investigation was designed to estimate the mass loading of nitrate (NO3−) and herbicides in spring water discharging from groundwater basins in an agriculturally dominated, mantled karst terrain. The loading was normalized to land use and NO3− and herbicide losses were compared to estimated losses in other agricultural areas of the Midwestern USA. Our study area consisted of two large karst springs that drain two adjoining groundwater basins (total area of 37.7 km2) in southwestern Illinois' sinkhole plain, USA. The springs and stream that they form were monitored for almost 2 years. Nitrate–nitrogen (NO3–N) concentrations at three monitoring sites were almost always above the background concentration (1.9...
Agriculture is the leading source of nonpoint-source pollution on a national scale. the driving force of nonpoint-source pollution is the rainfall-runoff process, which is the transformation of rainfall to streamflow. This is a complex, nonlinear, time-varying, and spatially distributed process on the watershed scale that is difficult to effectively model by conventional, deterministic means. Artificial neural networks (ANNs) offer a new approach to forecasting the hydrologic and water quality response of a watershed system. The goal of this work is to develop an ANN model as a long-term forecuating tool for predicting the hydrology and water quality of agricultural watersheds where the physical processes are difficult...
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Hydraulic connection between channels and floodplains (“connectivity”) is a fundamental determinant of ecosystem function in large floodplain rivers. Factors controlling material processing in these rivers depend not only on the degree of connectivity but also on the sediment conditions, nutrient loads and source. Nutrient cycling in the nutrient-rich upper Mississippi River (MISS) is relatively well studied, while that of less eutrophic tributaries is not (e.g., St Croix River; SACN). We examined components of nitrogen cycling in two floodplain rivers of contrasting nutrient enrichment and catchment land-use to test the hypothesis that N-cycling rates will be greater in the MISS with elevated nutrient-loads and...
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This USGS data release contains 1-kilometer resolution source-layer rasters used to predict redox conditions and contaminant concentrations in groundwater in the Fox-Wolf-Peshtigo watershed in Wisconsin and Michigan using random forest classification. The model output layers are 1-kilometer resolution rasters of the predicted probability of elevated concentrations of nitrate, iron, and arsenic. This data release supports the following publication: Tesoriero, A.J., Gronberg, J.M., Juckem, P.F., Miller, M.P., and Austin, B.P., 2017, Predicting redox-sensitive contaminant concentrations in groundwater using random forest classification: Water Resources Research, v. 53, https://doi.org/10.1002/2016WR020197.
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In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project. One of the major goals of the NAWQA project was to determine how river water quality has changed over time. To support that goal, long-term consistent and comparable monitoring has been conducted by the USGS on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS and other Federal, State, and local agencies also have collected long-term water-quality data to support their own assessments of changing water quality. In 2017, data from these multiple sources were combined to support one of the most comprehensive assessments...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This raster data set delineates the predicted probability of elevated volatile organic compound (VOC) concentrations in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set is a national map of predicted probability of nitrate contamination of shallow ground waters based on a logistic regression (LR) model. The LR model was used to predict the probability of nitrate contamination exceeding 4 mg/L in predominantly shallow, recently recharged ground waters of the United States. The model contains variables representing (1) nitrogen (N) fertilizer loading, (2) percent cropland-pasture, (3)...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set represents 1990 block group population density, in people per square kilometer, in the conterminous United States. This data set represents The data set was used as an input data layer for a national model to predict nitrate concentration in ground water used for drinking. Nolan and Hitt (2006) developed two national models to predict contamination of ground water by nonpoint sources of nitrate. The nonlinear approach...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set represents the percent of cropland/pasture/fallow land cover in the conterminous United States. The data set was used as an input data layer for a national model to predict nitrate concentration in shallow ground water. Nolan and Hitt (2006) developed two national models to predict contamination of ground water by nonpoint sources of nitrate. The nonlinear approach to national-scale Ground-WAter Vulnerability Assessment...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set represents the average annual nitrogen input from confined animal manure, 1992 and 1997, in kilograms per hectare, in the conterminous United States. The data set was used as an input data layer for a national model to predict nitrate concentration in shallow ground water. Nolan and Hitt (2006) developed two national models to predict contamination of ground water by nonpoint sources of nitrate. The nonlinear approach...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set represents the area of National Resources Inventory surface drainage, field ditch conservation practice, in square kilometers, in the conterminous United States. The data set was used as an input data layer for a national model to predict nitrate concentration in ground water used for drinking. Nolan and Hitt (2006) developed two national models to predict contamination of ground water by nonpoint sources of nitrate....
Denitrification was measured within a nitrate-contaminated aquifer on Cape Cod, Massachusetts, using natural gradient tracer tests with 15N nitrate. The aquifer contained zones of relatively high concentrations of nitrite (up to 77 μM) and nitrous oxide (up to 143 μM) and has been the site of previous studies examining ground water denitrification using the acetylene block technique. Small-scale (15–24 m travel distance) tracer tests were conducted by injecting 15N nitrate and bromide as tracers into a depth interval that contained nitrate, nitrite, nitrous oxide, and excess nitrogen gas. The timing of the bromide breakthrough curves at down-gradient wells matched peaks in 15N abundance above background for nitrate,...
Denitrification was measured within a nitrate-contaminated aquifer on Cape Cod, Massachusetts, using natural gradient tracer tests with 15N nitrate. The aquifer contained zones of relatively high concentrations of nitrite (up to 77 μM) and nitrous oxide (up to 143 μM) and has been the site of previous studies examining ground water denitrification using the acetylene block technique. Small-scale (15–24 m travel distance) tracer tests were conducted by injecting 15N nitrate and bromide as tracers into a depth interval that contained nitrate, nitrite, nitrous oxide, and excess nitrogen gas. The timing of the bromide breakthrough curves at down-gradient wells matched peaks in 15N abundance above background for nitrate,...
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This data set is a national map of predicted probability of nitrate contamination of shallow ground waters based on a logistic regression (LR) model. The LR model was used to predict the probability of nitrate contamination exceeding 4 mg/L in predominantly shallow, recently recharged ground waters of the United States. The model contains variables representing (1) nitrogen (N) fertilizer loading, (2) percent cropland-pasture, (3) natural log of human population density, (4) percent well-drained soils, (5) depth to the seasonally high water table, and (6) presence or absence of unconsolidated sand and gravel aquifers. Observed and average predicted probabilities associated with deciles of risk are well correlated...
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This record describes a series of comma separated files containing mean rates of monthly total nitrogen (TN), ammonium (NH4), and nitrate atmospheric (NO3) wet deposition attributed to NHDPlus version 2 (NHDv2, Moore and Dewald, 2016)) catchments for the period of record, October, 2006 to September, 2017. Units are in kilograms per square kilometer (kg/km2).
map background search result map search result map Source and model output layers used for the prediction and display of the probability of elevated concentrations of redox-sensitive constituents in groundwater in the Fox-Wolf-Peshtigo watershed in Wisconsin and Michigan Determine nutrient conditions, cycling, and biological effects in two riverine parks, St.Croix National Scenic River (SACN) and Upper Mississippi River National Recreation Area (MNRA): Data BLM REA CBR 2010 Probability of nitrate contamination of recently rechargedground waters in the conterminous United States Mean monthly atmospheric wet deposition attributed to NHDplus version 2, October 2006 through September 2017 Water-quality and streamflow datasets used in Weighted Regressions on Time, Discharge, and Season (WRTDS) models to determine trends in the Nation’s rivers and streams, 1972-2017 (output data) Río Icacos, Puerto Rico, Turbidity, FDOM, and Water Temperature, March 2017 to March 2019 Probability of Elevated Volatile Organic Compound (VOC) Concentrations in Groundwater in the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007 Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for drainageditch (gwava-dw_ddit) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for population density (gwava-dw_popd) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for confined manure (gwava-s_conf) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for cropland/pasture/fallow (gwava-s_crpa) Probability of nitrate contamination of recently recharged ground waters in the conterminous United States Río Icacos, Puerto Rico, Turbidity, FDOM, and Water Temperature, March 2017 to March 2019 Probability of Elevated Volatile Organic Compound (VOC) Concentrations in Groundwater in the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007 Determine nutrient conditions, cycling, and biological effects in two riverine parks, St.Croix National Scenic River (SACN) and Upper Mississippi River National Recreation Area (MNRA): Data Source and model output layers used for the prediction and display of the probability of elevated concentrations of redox-sensitive constituents in groundwater in the Fox-Wolf-Peshtigo watershed in Wisconsin and Michigan BLM REA CBR 2010 Probability of nitrate contamination of recently rechargedground waters in the conterminous United States Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for population density (gwava-dw_popd) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Input data set for drainageditch (gwava-dw_ddit) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for confined manure (gwava-s_conf) Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for cropland/pasture/fallow (gwava-s_crpa) Water-quality and streamflow datasets used in Weighted Regressions on Time, Discharge, and Season (WRTDS) models to determine trends in the Nation’s rivers and streams, 1972-2017 (output data) Mean monthly atmospheric wet deposition attributed to NHDplus version 2, October 2006 through September 2017 Probability of nitrate contamination of recently recharged ground waters in the conterminous United States