Overview of the National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance Program

Bolivar, S.L.

doi:10.2172/5046710

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…Clearly there is a need for existing, HR stream sediment geochemical data; this is often available from mineral exploration studies. For example, the National Uranium Resource Evaluation Programme in the USA has around 400,000 stream sediment samples (Bolivar, 1980), compared with geochemistry for only 1323 soil samples available nationally (Boerngen and Shacklette, 1981).…”

Section: Discussionmentioning

confidence: 99%

National-scale estimation of potentially harmful element ambient background concentrations in topsoil using parent material classified soil:stream–sediment relationships

Appleton

Rawlins

Thornton

2008

Applied Geochemistry

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Regulatory authorities require estimates of ambient background concentrations (ABCs) of potentially harmful elements (PHEs) in topsoil; such data are currently not available in many countries. High resolution soil geochemical data exist for only part of England and Wales (E&W), whilst stream sediment data cover the entire landscape. We present a novel methodology for estimating soil equivalent ABCs for PHEs from high-resolution (HR) stream sediment geochemical data grouped by common parent materials (PM), using arsenic (As) as an example. We use geometric mean (GM) values for local PM groups to investigate different approaches for transforming sediment to soil equivalent concentrations. We use holdout validation to assess: i) the optimum number of samples for calculating local GM values, and ii) the optimum scale at which to group data when using linear regression analysis to estimate GM soil ABCs from local sediment geochemical values. Holdout validation showed that the smallest differences were generally observed when five observations were used to calculate the GM and that these should be grouped over the smallest possible area in order to encompass soils over PMs with elevated GM As concentrations. We estimate and map GM ABCs for arsenic in mineral soil across all of E&W within delineations of PM polygons.Errors for the estimation of soil equivalent GM As ABCs based on sediment data for an independent validation set were of a similar magnitude to those from holdout validation applied to the original data suggesting the approach is robust. Our estimates of soil equivalent ABCs suggest that As exceeds the regulatory threshold used in risk assessments for residential land use (20 mg kg -1 ) across 16 % of the landscape of E&W. We discuss the applicability of the method for cognate landscapes, and potential refinements.

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Section: Discussionmentioning

confidence: 99%

National-scale estimation of potentially harmful element ambient background concentrations in topsoil using parent material classified soil:stream–sediment relationships

Appleton

Rawlins

Thornton

2008

Applied Geochemistry

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“…• BSPconc values represent the potential contribution of P from the local area adjacent to the sampling site (Bolivar, 1980).…”

Section: Bed-sediment Phosphorus Concentration Source Datamentioning

confidence: 99%

“…If possible, no sites were selected that were closer than 1.5 kilometer (km) to another site, and the area drained was no more than three times the area of the grid so that the maximum size of a basin draining to a site would be 90 km 2 . The largest headwater stream within the grid was chosen if the site was accessible to field personnel (Bolivar, 1980), and an attempt to sample most streams draining from 8 to 26 km 2 (3 to 10 square miles) was made (Ferguson and others, 1976). Samples were collected upstream from roads, ponds or other disturbances that could have altered the sampling results, and samples were collected outside of populated areas (Information Systems Programs, Energy Resources Institute, 1985) in order to accurately represent the local-scale variation in sediment mineral composition with surficial geology or other geographical characteristics.…”

Section: Data Layer Productsmentioning

confidence: 99%

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

Terziotti¹,

Hoos²,

Harned³

et al. 2010

Scientific Investigations Map

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As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

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“…Savannah River, Oak Ridge, Los Alamos, and Lawrence Livermore (Bolivar, 1980) . Geochemical samples collected early in the HSSR were analyzed for uranium only because the NURE program was implemented to evaluate the uranium resources of the United States.…”

Section: Introductionmentioning

confidence: 99%

The geochemical atlas of Alaska

Bolivar

Broxton

Freeman

et al. 1987

Journal of Geochemical Exploration

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Overview of the National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance Program

Cited by 5 publications

References 12 publications

National-scale estimation of potentially harmful element ambient background concentrations in topsoil using parent material classified soil:stream–sediment relationships

National-scale estimation of potentially harmful element ambient background concentrations in topsoil using parent material classified soil:stream–sediment relationships

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

The geochemical atlas of Alaska

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