Download or read book Using Nitrogen and Oxygen Isotope Compositions of Nitrate to Distinguish Contaminant Sources in Hanford Soil and Groundwater written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The nitrogen ([delta]15N) and oxygen ([delta]18O) isotopic compositions of nitrate in the environment are primarily a function of the source of the nitrate. The ranges of isotopic compositions for nitrate resulting from common sources are outlined in Figure 1 from Kendall (1998). As noted on Figure 1, processes such as microbial metabolism can modify the isotopic compositions of the nitrate, but the effects of these processes are generally predictable. At Hanford, nitrate and other nitrogenous compounds were significant components of most of the chemical processes used at the site. Most of the oxygen in nitrate chemicals (e.g., nitric acid) is derived from atmospheric oxygen, giving it a significantly higher [delta]18O value (+23.5{per_thousand}) than naturally occurring nitrate that obtains most of its oxygen from water (the [delta]18O of Hanford groundwater ranges from -14{per_thousand} to -18{per_thousand}). This makes it possible to differentiate nitrate from Hanford site activities from background nitrate at the site (including most fertilizers that might have been used prior to the Department of Energy plutonium production activities at the site). In addition, the extreme thermal and chemical conditions that occurred during some of the waste processing procedures and subsequent waste storage in select single-shell tanks resulted in unique nitrate isotopic compositions that can be used to identify those waste streams in soil and groundwater at the site (Singleton et al., 2005; Christensen et al., 2007). This report presents nitrate isotope data for soil and groundwater samples from the Hanford 200 Areas and discusses the implications of that data for potential sources of groundwater contamination.
Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!
Download or read book Identifying Sources of Subsurface Nitrate Pollution with Stable Nitrogen Isotopes written by Timothy J. Wolterink and published by . This book was released on 1979 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Stable Isotopes of Carbon Nitrogen and Sulfur to Identify Sources of Nitrogen in Surface Waters in the Lower Susquehanna River Basin Pennsylvania written by Charles A. Cravotta and published by . This book was released on 2002 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determining the Source of Nitrate in Ground Water by Nitrogen Isotope Studies written by Charles W. Kreitler and published by . This book was released on 1975 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book California GAMA Special Study written by and published by . This book was released on 2010 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates nitrate contamination of a deep municipal drinking water production well in Ripon, CA to demonstrate the utility of natural groundwater tracers in constraining the sources and transport of nitrate to deep aquifers in the Central Valley. The goal of the study was to investigate the origin (source) of elevated nitrate and the potential for the deep aquifer to attenuate anthropogenic nitrate. The site is ideal for such an investigation. The production well is screened from 165-325 feet below ground surface and a number of nearby shallow and deep monitoring wells were available for sampling. Furthermore, potential sources of nitrate contamination to the well had been identified, including a fertilizer supply plant located approximately 1000 feet to the east and local almond groves. A variety of natural isotopic and dissolved gas tracers including 3H-3He groundwater age and the isotopic composition of nitrate are applied to identify nitrate sources and to characterize nitrate transport. An advanced method for sampling production wells is employed to help identify contaminant contributions from specific screen intervals. Nitrate transport: Groundwater nitrate at this field site is not being actively denitrified. Groundwater parameters indicate oxic conditions, the dissolved gas data shows no evidence for excess nitrogen as the result of denitrification, and nitrate-N and -O isotope compositions do not display patterns typical of denitrification. Contaminant nitrate source: The ambient nitrate concentration in shallow groundwater at the Ripon site (≈12 mg/L as nitrate) is typical of shallow groundwaters affected by recharge from agricultural and urban areas. Nitrate concentrations in Ripon City Well 12 (50-58 mg/L as nitrate) are significantly higher than these ambient concentrations, indicating an additional source of anthropogenic nitrate is affecting groundwater in the capture zone of this municipal drinking water well. This study provides two new pieces of evidence that the Ripon Farm Services Plant is the source of elevated nitrate in Ripon City Well 12. (1) Chemical mass balance calculations using nitrate concentration, nitrate isotopic composition, and initial tritium activity all indicate that that the source water for elevated nitrate to Ripon City Well 12 is a very small component of the water produced by City Well 12 and thus must have extremely high nitrate concentration. The high source water nitrate concentration (≈1500 mg/L as nitrate) required by these mass balance calculations precludes common sources of nitrate such as irrigated agriculture, dairy wastewater, and septic discharge. Shallow groundwater under the Ripon Farm Services RFS plant does contain extremely high concentrations of nitrate (>1700 mg/L as nitrate). (2) Nitrogen and oxygen isotope compositions of nitrate indicate that the additional anthropogenic nitrate source to Ripon City Well 12 is significantly enriched in [delta]18O-NO3, an isotopic signature consistent with synthetic nitrate fertilizer, and not with human or animal wastewater discharge (i.e. dairy operations, septic system discharge, or municipal wastewater discharge), or with organic fertilizer. Monitoring wells on and near the RFS plant also have high [delta]18O-NO3, and the plant has handled and stored synthetic nitrate fertilizer that will have this isotopic signature. The results described here highlight the complexity of attributing nitrate found in long screened, high capacity wells to specific sources. In this case, the presence of a very high concentration source near the well site combined with sampling using multiple isotopic tracer techniques and specialized depth-specific techniques allowed fingerprinting of the source in the mixed-age samples drawn from the production well.
Download or read book Nuclear News written by and published by . This book was released on 2007 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vulnerability Assessment of Nitrate Leaching on the Regional Scale Using Isotope Techniques written by Myriam Maria Stoewer and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Zusammenfassung: Groundwater is an important source of drinking water, but its quality is threatened by contamination with nitrate. In order to prevent groundwater contamination, knowledge about potential nitrate sources, their pathways and time lag between sources and drinking water wells is required. Still, i) simple methods to quantify nitrate fluxes are missing, ii) the applicability of stable isotopes of nitrate in nitrate source identification in grassland systems remains unknown, and iii) there is a lack of physically based modeling approaches focusing on the spatially resolved estimation of groundwater vulnerability to nitrate contamination. Thus, the objectives of the thesis are to i) quantify nitrate leaching in soils, ii) identify major sources of nitrate in aquifers, and iii) determine the intrinsic and nitrate specific aquifer vulnerability. The objectives were realized in a pre-alpine area with oligotrophic aquifers used for drinking water supply. Different isotopic and environmental tracers were used to understand the local hydrogeology and the fate of nitrate and related dynamic transformation processes. At farmed grassland sites, analysis of nitrate concentration in soil water below the root zone using suction cups was combined with groundwater recharge rates estimated from vertical deuterium profiles in soil to calculate nitrate fluxes. Stable isotopes of nitrate were analyzed in surface water, soil water and groundwater and compared with the distinct isotope composition of nitrate in potential sources. Local tritium concentrations were used in combination with a lumped-parameter model to calculate the mean residence times (MRTt) and MRTt distributions of local groundwater wells. The intrinsic and nitrate specific vulnerability of groundwater was spatially assessed (GIS) based on the approximation of the total mean residence time (MRT) and the residence time distribution as well as consulting data on nitrate leaching.Measured nitrate concentration below the root zone varies between 0 and 90 mg NO3- L-1. Estimated groundwater recharge rates cover a range of 430 to 926 mm yr-1. Nitrate leaching (0.2 to 41 kg NO3-N ha-1 yr-1) at grassland sites is highest in spring and fall. At farmed sites, nitrate leaching is positively related to fertilizer input rather than land use category (organic, conventional). Nitrate isotope values indicate that nitrate derive from ammonium nitrification of multiple sources, such as atmospheric deposition, mineral fertilizer, organic fertilizer and soil organic matter. The results suggest that local nitrate input is buffered in the upper soil, due to incorporation into soil organic matter, and released by subsequent mineralization and nitrification. Due to observed oxic conditions present in groundwater, the natural attenuation potential regarding nitrate (denitrification) is low. Modeled MRTt varies between 5 and 21 years, indicating that investigated groundwater wells are less vulnerable to short-term impacts. Though, such moderate to high MRT itself do not protect groundwater against contamination with nitrate. The observed MRT varies between smaller than 5 and 51 years. In comparison, the distribution curves generated from both modeling approaches show that the GIS approach neglects fast flow paths lower than five years. The results of the specific vulnerability assessment characterize the observation area as less vulnerable to groundwater contamination with nitrate. This is achieved by not exceeding the drinking water threshold due to the absence of land use, inducing high loads of nitrate leaching. Nevertheless, any increase in fertilizer application could change the nitrate level in groundwater due to oxic conditions and the underestimation of fast flow paths. Finally it is shown that time lags associated with land use are a perfect tool and need to be considered for management strategies. Consequently, areas attributed to low MRT are vulnerable to short-term contaminations but provide the chance to react fast in terms of groundwater protection management. On the contrary, areas attributed to high MRT might favor the natural attenuation and dilution of nitrate, but once nitrate has entered the groundwater, remediation strategies struggle with the time lag which results in long-term impacts on groundwater quality.The study shows that the combination of methods dealing with different scales results in a comprehensive assessment of groundwater vulnerability regarding nitrate leaching. Pre-alpine oligotrophic aquifers mainly covered with grassland require the need to reduce nitrogen input in groundwater catchments in order to protect water quality. This applies for areas vulnerable to short-term impacts as well as areas vulnerable to long-term impacts. In future, investigations examining the applicability of nitrogen in soil organic matter into fertilizer management are required in order to distinguish between organic fertilizer and sewage. In addition, nitrate source identification in such catchments should be combined with sophisticated tracers in order to distinguish between organic fertilizer and sewage effluent. Furthermore, the spatial assessment of groundwater vulnerability to nitrate contamination emphasizes the need to include the impact of hydrological dynamics as well as temporal and spatial variability in terms of land use
Download or read book Using Stable Isotopes as a Tool to Study Streamwater and Soil Nitrate written by Heidi Hales and published by . This book was released on 2005 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Stable Isotopes of Nitrogen and Oxygen to Identify Sources of Nitrate in Three Creeks Durham County North Carolina 2011 12 written by Kristen Bukowski McSwain and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determining the Source of Nitrate Contamination in Groundwater Using 15 nitrogen as a Tracer written by Kevin Michael Morrissey and published by . This book was released on 1989 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate nitrogen and Nitrate oxygen Isotope Ratios for Identification of Nitrate Sources and Dominant Nitrogen Cycle Processes in a Tile drained Dryland Agricultural Field written by Christopher Joshua Kelley and published by . This book was released on 2011 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Isotope Tracers of Nitrogen Sources to the Neuse River North Carolina written by and published by . This book was released on 1990 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nutrient concentrations in surface water and groundwater and nitrate source identification using stable isotope analysis in the Barnegat Bay Little Egg Harbor Watershed New Jersey 2010 11 written by Christine Wieben and published by CreateSpace. This book was released on 2013 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five streams in the Barnegat Bay-Little Egg Harbor (BB- LEH) watershed in southern New Jersey were sampled for nutrient concentrations and stable isotope composition under base-flow and stormflow conditions, and during the growing and nongrowing seasons, to help quantify and identify sources of nutrient loading. Samples were analyzed for concentrations of total nitrogen, ammonia, nitrate plus nitrite, organic nitro- gen, total phosphorus, and orthophosphate, and for nitrogen and oxygen stable isotope ratios. Concentrations of total nitrogen in the five streams appear to be related to land use, such that streams in subbasins characterized by extensive urban development (and histori- cal agricultural land use)-North Branch Metedeconk and Toms Rivers-exhibited the highest total nitrogen concentra- tions (0.84-1.36 milligrams per liter (mg/L) in base flow). Base-flow total nitrogen concentrations in these two streams were dominated by nitrate; nitrate concentrations decreased during storm events as a result of dilution by storm runoff.
Download or read book Sources of Groundwater Nitrate Revealed Using Residence Time and Isotope Methods written by and published by . This book was released on 2004 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrate concentrations approaching and greater than the maximum contaminant level (MCL) are impairing the viability of many groundwater basins as drinking water sources. Nitrate isotope data are effective in determining contaminant sources, especially when combined with other isotopic tracers such as stable isotopes of water and tritium-helium ages to give insight into the routes and timing of nitrate inputs to the flow system. This combination of techniques is demonstrated in Livermore, CA, where it is determined that low nitrate reclaimed wastewater predominates in the northwest, while two flowpaths with distinct nitrate sources originate in the southeast. Along the eastern flowpath, [delta]15N values greater than 10{per_thousand} indicate that animal waste is the primary source. Diminishing concentrations over time suggest that contamination results from historical land use practices. The other flowpath begins in an area where rapid recharge, primarily of low-nitrate imported water (identified by stable isotopes of water and a tritium-helium residence time of less than 1 year), mobilizes a significant local nitrate source, bringing groundwater concentrations up to 53 mg NO3 L−1. In this area, artificial recharge of imported water via local arroyos increases the flux of nitrate to the regional aquifer. The low [delta]15N value (3.1{per_thousand}) in this location implicates synthetic fertilizer. In addition to these anthropogenic sources, natural nitrate background levels between 15 and 20 mg NO3 L−1 are found in deep wells with residence times greater than 50 years.
Download or read book Assessment of the Origin and Fate of Nitrate from Soil Lysimeters Using Stable Nitrogen Isotopes written by Keith Edwin Knoke and published by . This book was released on 1997 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Probability of Detecting Elevated Concentrations of Nitrate in Ground Water in a Six county Area of South central Idaho written by Kenneth D. Skinner and published by . This book was released on 2003 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
