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Andrea Foster, Ph.D.

Andrea is a Research Geologist with the Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, CA and came to the USGS, Menlo Park in 1999

Andrea attended high school in Bloomington, Indiana and Frankfort, Kentucky, graduating in 1988. She was a matriculated geology major at Howard University (Washington, DC) and Indiana University (Bloomington), obtaining her BS Geology from the latter institution in 1992.

 

PRESENT ASSIGNMENTS

  • Investigating the relationship between arsenic solid-phase speciation and arsenic relative bioaccessibility and bioavailability 
  • Improving EPA's chromate extraction method though spectroscopic quantification of solid-phase chromate
  • Identifying solid-phase species of chromium and the potential for redox transformations of Cr in the vicinity of Hinkley, CA
  • Investigation of gallium and rare earth element speciation in acid-sulfate alteration haloes of mineral deposits
  • Development of micro-Raman spectroscopic methods for in-situ measurement of dissolved and solid-phase toxic elements and micro-mineralogical ID

 

PAST ASSIGNMENTS

  • Toxicity of tellurium and other scarce, technologically-important trace elements in aquatic invertebrates
  • Spectroscopic studies of tellurium mineralogy to support studies of tellurium in mine wastes
  • Arsenic solid-phase speciation at the Lava Cap Mine Superfund Site, Nevada City, CA
  • Arsenic solid-phase speciation in surface and aquifer sediments from Bangladesh
  • Feasibililty studies for passive bioreactor using Leptothrix, a ferric-hydroxide precipitating bacterium
  • Microbial community diversity in mining-impacted intertidal zones of Prince William Sound, AK.
  • Toxicity of water in intertidal zones impacted by mining of VMS deposits, Prince William Sound, AK
  • Composition and diversity of mercury

Professional Experience

  • 2010 - Soft X-ray Summer School, Stanford University

  • 2006 - Multivariate Analysis of Hydrological, Biological, and Chemical Data (ID 3045), USGS, Denver, CO. (5 days)

  • 2000 - Field Emission Scanning Electron Microscopy: Better Understanding and Usage of the SEM for Lab Work, USGS, Menlo Park (2 days)

  • 1999 - Assisted use/training in TEM/AEM at the National Center for Electron Microscopy, Berkeley, CA (2 days)

  • 1999 - Synchrotron-based powder XRD short course, Stanford Synchrotron Radiation Laboratory (1 day)

  • 1998 - Geomicrobiological Research in Norm Pace’s microbiology lab, Berkeley, CA (3 months)

  • 1998 - Microbial Diversity Course, Marine Biological Laboratory, Woods Hole, MA (8 weeks)

Education and Certifications

  • 1992-1999 Stanford University, Ph.D., Geological and Environmental Sciences

  • 1990-1992 Indiana University, B.S., Geology, (with Honors); Mathematics minor

  • 1988-1990 Howard University, Geology major

Science and Products

link
Serpentinized peridotite that has been cut to reveal the serpentine minerals inside surrounded by a thin brown outer layer.

Ultramafic lands: Sustainability Challenges and Resource Opportunities

Ultramafic lands are geologically and ecologically diverse areas that host naturally elevated concentrations of chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), and scandium (Sc). While Cr is a potential carcinogen, Co, Mn, Ni, and Sc are considered critical minerals in the United States owing to their importance in current electric battery formulations. The research conducted...
By
Energy and Minerals Mission Area, Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center
link

Ultramafic lands: Sustainability Challenges and Resource Opportunities

Ultramafic lands are geologically and ecologically diverse areas that host naturally elevated concentrations of chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), and scandium (Sc). While Cr is a potential carcinogen, Co, Mn, Ni, and Sc are considered critical minerals in the United States owing to their importance in current electric battery formulations. The research conducted...
Learn More
link
MC-ICP-MS equipment

Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center
link

Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
Learn More

Optical Petrography, Bulk Chemistry, Micro-scale Mineralogy/Chemistry, and Bulk/Micron-Scale Solid-Phase Speciation of Natural and Synthetic Solid Phases Used in Chromium Sequestration and Re-oxidation Experiments with Sand and Sediment from Hinkley, CA

This data release contains macro and microscale datasets describing the abundance, valence states, and mineral residence(s) of chromium, iron, and manganese in natural and synthetic mineral mixtures used in laboratory experiments designed to simulate dynamic conditions in an engineered aquifer system [see Izbicki and Groover (2018) and Miller and others (2020)]. The landing page contains primary m
By
Geology, Minerals, Energy, and Geophysics Science Center

Geochemical and mineralogical data for mine waste from Sulphur Bank Mercury Mine, Lake County, California

This data release presents geochemical and mineralogical data from mine waste at Sulphur Bank Mercury Mine (SBMM). This work is performed in cooperation with the US Environmental Protection Agency (EPA) to characterize sources of contamination at the SBMM cleanup site. A total of 23 samples were collected: 15 samples were collected by USGS from various waste piles (14 composites from the top 0-5cm
By
California Water Science Center

Phytostabilization in Polymetallic Tailings using Compost and Endophyte Additions

Mining wastes can pose environmental hazards. These hazards can be mitigated by promoting the growth of native plants that can stabilize the mine wastes and potentially toxic elements in situ (i.e., phytostabilization). We grew a widespread perennial grass species (Bouteloua curtipendula) in dolomite amended polymetallic tailings from a historic mine in southeastern Arizona (USA). We applied a com
By
Geology, Minerals, Energy, and Geophysics Science Center

Abiotic sorption of glucose, glutamic acid, hydroxybenzoic acid, and oxalic acid onto amorphous aluminum hydroxide, feldspar, ferrihydrite, and kaolinite

Abiotic sorption experiments were conducted with four carbon substrates (glucose, glutamic acid, oxalic acid, para-hydroxybenzoic acid) on four clay minerals (kaolinite, feldspar, ferrihydrite, amorphous aluminum hydroxide) after sterilization by gamma irradiation. The adsorption isotherms were carried across a range of substrate carbon concentrations (0, 20, 100, and 500 mg carbon per L) and pH c
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center

Grass Growth in Mining Wastes with Compost and Endophyte Additions

Phytostabilization reduces the mobility of inorganic contaminants by establishing or enhancing plant growth. For small, remote, or abandoned mines, phytostabilization may reduce potential environmental hazards—provided plants can establish and grow. We grew a widespread perennial grass, Bouteloua curtipendula, in mining wastes with and without soil (compost, lime) and microbial amendments (endophy
By
Geology, Minerals, Energy, and Geophysics Science Center

Batch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide

These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic aci
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Laboratory data from testing parameters of EPA Method 3060A on Soils Contaminated with Chromium Ore Processing Residue 2013-2016

It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from solids containing chromium ore processing residue (COPR). We systematically tested modifications to prescribed parameters of EPA 3060A towards improving extraction efficiency of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil from New Jersey (NJ). The alkaline extraction fluid leached Al, Si, and B from th
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Filter Total Items: 30

A combined compost, dolomite, and endophyte addition is more effective than single amendments for improving phytorestoration of metal contaminated mine tailings

Background and aimsRe-vegetation of mining-impacted landscapes reduces transport of toxic elements while improving soil fertility. This study evaluated whether the planting of a native perennial grass with a consortium of diazotrophic microbial endophytes and municipal waste compost—alone and in combination—enhanced plant growth while stabilizing metal(loids) in dolomite-amended tailings from a hi
Authors
Courtney Creamer, Mary-Catherine Leewis, Martina Kracmarova, Jakub Papík, Sean Kacur, John Freeman, Ondrej Uhlik, Andrea L. Foster
By
Geology, Minerals, Energy, and Geophysics Science Center

Compost, plants and endophytes versus metal contamination: Choice of a restoration strategy steers the microbiome in polymetallic mine waste

Finding solutions for the remediation and restoration of abandoned mining areas is of great environmental importance as they pose a risk to ecosystem health. In this study, our aim was to determine how remediation strategies with (i) compost amendment, (ii) planting a metal-tolerant grass Bouteloua curtipendula, and (iii) its inoculation with beneficial endophytes influenced the microbiome of meta
Authors
Martina Kracmarova, Jakub Papik, Ondrej Uhlik, John Freeman, Andrea L. Foster, Mary-Catherine Leewis, Courtney Creamer
By
Geology, Minerals, Energy, and Geophysics Science Center

Chromium in minerals and selected aquifer materials

Between 1952 and 1964, hexavalent chromium, Cr(VI), was released into groundwater from a Pacific Gas and Electric Company (PG&E) compressor station in Hinkley, California, in the western Mojave Desert 80 miles northeast of Los Angeles, California. In 2015, the extent of anthropogenic Cr(VI) in groundwater in Hinkley and Water Valleys was uncertain, but some Cr(VI) in groundwater may be naturally o
Authors
Krishangi D. Groover, John A. Izbicki, William Benzel, Jean Morrison, Andrea L. Foster
By
Water Resources Mission Area, California Water Science Center

Sequestration and reoxidation of chromium in experimental microcosms

Groundwater containing hexavalent chromium, Cr(VI), downgradient from the Pacific Gas and Electric Company (PG&E) Hinkley compressor station in the Mojave Desert, 80 miles northeast of Los Angeles, California, is undergoing bioremediation using added ethanol as a reductant in a volume of the aquifer defined as the in situ reactive zone (IRZ). This treatment reduces Cr(VI) to trivalent chromium, Cr
Authors
Laurence G. Miller, Callum E. Bobb, Andrea L. Foster, Emily G. Wright, Stacy C. Bennett, Krishangi D. Groover, John A. Izbicki
By
Water Resources Mission Area, California Water Science Center

Microbial endophytes and compost improve plant growth in two contrasting types of hard rock mining waste

The re-vegetation of mining wastes with native plants is a comparatively low-cost solution for mine reclamation. However, re-vegetation fails when extreme pH values, low organic matter, or high concentrations of phytotoxic elements inhibit plant establishment and growth. Our aim was to determine whether the combined addition of municipal waste compost and diazotrophic endophytes (i.e., microorgani
Authors
Courtney Creamer, Mary-Catherine Leewis, Francesca C. Governali, John Freeman, Floyd Gray, Emily G. Wright, Andrea L. Foster
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center

Mineralogy dictates the initial mechanism of microbial necromass association

Soil organic matter (SOM) improves soil fertility and mitigates disturbance related to climate and land use change. Microbial necromass (the accumulated cellular residues of microorganisms) comprises the majority of soil C, yet the formation and persistence of necromass in relation to mineralogy is poorly understood. We tested whether soil minerals had different microbial necromass association mec
Authors
Courtney Creamer, Andrea L. Foster, Corey Lawrence, Jack McFarland, Marjorie S. Schulz, Mark Waldrop
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center

Mineralogical characterization of weathered outcrops as a tool for constraining water chemistry predictions during project planning

Weathered samples from naturally exposed outcrops of troctolite associated with a magmatic Ni-Cu sulphide deposit were characterized by synchrotron-based micro-X-ray fluorescence mapping (µ-XRF) and X-ray absorption spectroscopy (XAS), as well as by lab-based X-ray diffraction, electron microscopy, Raman spectroscopy and wet chemical methods. Metal mobility in weathered samples was assessed using
Authors
Tamara Diedrich, Paul Fix, Andrea L. Foster
By
Energy and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center

Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils

It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil. Aluminum and Si were the major elements dissolved from NIST 27
Authors
Christopher T. Mills, Carleton R. Bern, Ruth E. Wolf, Andrea L. Foster, Jean Morrison, William Benzel
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Copper speciation in variably toxic sediments at the Ely Copper Mine, Vermont, United States

At the Ely Copper Mine Superfund site, Cu concentrations exceed background values in both streamwater (160–1200 times) and sediments (15–79 times). Previously, these sediment samples were incubated with laboratory test organisms, and they exhibited variable toxicity for different stream sites. In this study we combined bulk- and microscale techniques to determine Cu speciation and distribution in
Authors
Bryn E. Kimball, Andrea L. Foster, Robert R. Seal, Nadine M. Piatak, Samuel M. Webb, Jane M. Hammarstrom
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Energy & Minerals Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls

Although As concentrations have been investigated in shallow groundwater from the Hetao basin, China, less is known about U and As distributions in deep groundwater, which would help to better understand their origins and fate controls. Two hundred and ninety-nine groundwater samples, 122 sediment samples, and 14 rock samples were taken from the northwest portion of the Hetao basin, and analyzed f
Authors
Huaming Guo, Yongfeng Jia, Richard B. Wanty, Yuxiao Jiang, Weiguang Zhao, Wei Xiu, Jiaxing Shen, Yuan Li, Yongsheng Cao, Yang Wu, Di Zhang, Chao Wei, Yilong Zhang, Wengeng Cao, Andrea L. Foster
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center

Arsenic speciation in solids using X-ray absorption spectroscopy

Synchrotron-based X-ray absorption spectroscopy (XAS) is an in situ, minimally-destructive, element-specific, molecular-scale structural probe that has been employed to study the chemical forms (species) of arsenic (As) in solid and aqueous phases (including rocks, soils, sediment, synthetic compounds, and numerous types of biota including humans) for more than 20 years. Although several excellent
Authors
Andrea L. Foster, Chris S. Kim
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center

Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site, Nevada City, CA

Background A realistic estimation of the health risk of human exposure to solid-phase arsenic (As) derived from historic mining operations is a major challenge to redevelopment of California's famed "Mother Lode" region. Arsenic, a known carcinogen, occurs in multiple solid forms that vary in bioaccessibility. X-ray absorption fine-structure spectroscopy (XAFS) was used to identify and quantify th
Authors
Andrea L. Foster, Roger P. Ashley, James J. Rytuba

Science and Products

link
Serpentinized peridotite that has been cut to reveal the serpentine minerals inside surrounded by a thin brown outer layer.

Ultramafic lands: Sustainability Challenges and Resource Opportunities

Ultramafic lands are geologically and ecologically diverse areas that host naturally elevated concentrations of chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), and scandium (Sc). While Cr is a potential carcinogen, Co, Mn, Ni, and Sc are considered critical minerals in the United States owing to their importance in current electric battery formulations. The research conducted...
By
Energy and Minerals Mission Area, Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center
link

Ultramafic lands: Sustainability Challenges and Resource Opportunities

Ultramafic lands are geologically and ecologically diverse areas that host naturally elevated concentrations of chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), and scandium (Sc). While Cr is a potential carcinogen, Co, Mn, Ni, and Sc are considered critical minerals in the United States owing to their importance in current electric battery formulations. The research conducted...
Learn More
link
MC-ICP-MS equipment

Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center
link

Macro and Micro Analytical Methods Development

The Macro and Micro Analytical Methods Development Project (MMAMD) provides access to the expertise of highly experienced research scientists and state of the art analytical instrumentation to develop new and unique analytical capabilities to solve complex problems beyond routine analysis.
Learn More

Optical Petrography, Bulk Chemistry, Micro-scale Mineralogy/Chemistry, and Bulk/Micron-Scale Solid-Phase Speciation of Natural and Synthetic Solid Phases Used in Chromium Sequestration and Re-oxidation Experiments with Sand and Sediment from Hinkley, CA

This data release contains macro and microscale datasets describing the abundance, valence states, and mineral residence(s) of chromium, iron, and manganese in natural and synthetic mineral mixtures used in laboratory experiments designed to simulate dynamic conditions in an engineered aquifer system [see Izbicki and Groover (2018) and Miller and others (2020)]. The landing page contains primary m
By
Geology, Minerals, Energy, and Geophysics Science Center

Geochemical and mineralogical data for mine waste from Sulphur Bank Mercury Mine, Lake County, California

This data release presents geochemical and mineralogical data from mine waste at Sulphur Bank Mercury Mine (SBMM). This work is performed in cooperation with the US Environmental Protection Agency (EPA) to characterize sources of contamination at the SBMM cleanup site. A total of 23 samples were collected: 15 samples were collected by USGS from various waste piles (14 composites from the top 0-5cm
By
California Water Science Center

Phytostabilization in Polymetallic Tailings using Compost and Endophyte Additions

Mining wastes can pose environmental hazards. These hazards can be mitigated by promoting the growth of native plants that can stabilize the mine wastes and potentially toxic elements in situ (i.e., phytostabilization). We grew a widespread perennial grass species (Bouteloua curtipendula) in dolomite amended polymetallic tailings from a historic mine in southeastern Arizona (USA). We applied a com
By
Geology, Minerals, Energy, and Geophysics Science Center

Abiotic sorption of glucose, glutamic acid, hydroxybenzoic acid, and oxalic acid onto amorphous aluminum hydroxide, feldspar, ferrihydrite, and kaolinite

Abiotic sorption experiments were conducted with four carbon substrates (glucose, glutamic acid, oxalic acid, para-hydroxybenzoic acid) on four clay minerals (kaolinite, feldspar, ferrihydrite, amorphous aluminum hydroxide) after sterilization by gamma irradiation. The adsorption isotherms were carried across a range of substrate carbon concentrations (0, 20, 100, and 500 mg carbon per L) and pH c
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center

Grass Growth in Mining Wastes with Compost and Endophyte Additions

Phytostabilization reduces the mobility of inorganic contaminants by establishing or enhancing plant growth. For small, remote, or abandoned mines, phytostabilization may reduce potential environmental hazards—provided plants can establish and grow. We grew a widespread perennial grass, Bouteloua curtipendula, in mining wastes with and without soil (compost, lime) and microbial amendments (endophy
By
Geology, Minerals, Energy, and Geophysics Science Center

Batch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide

These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic aci
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Laboratory data from testing parameters of EPA Method 3060A on Soils Contaminated with Chromium Ore Processing Residue 2013-2016

It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from solids containing chromium ore processing residue (COPR). We systematically tested modifications to prescribed parameters of EPA 3060A towards improving extraction efficiency of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil from New Jersey (NJ). The alkaline extraction fluid leached Al, Si, and B from th
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Filter Total Items: 30

A combined compost, dolomite, and endophyte addition is more effective than single amendments for improving phytorestoration of metal contaminated mine tailings

Background and aimsRe-vegetation of mining-impacted landscapes reduces transport of toxic elements while improving soil fertility. This study evaluated whether the planting of a native perennial grass with a consortium of diazotrophic microbial endophytes and municipal waste compost—alone and in combination—enhanced plant growth while stabilizing metal(loids) in dolomite-amended tailings from a hi
Authors
Courtney Creamer, Mary-Catherine Leewis, Martina Kracmarova, Jakub Papík, Sean Kacur, John Freeman, Ondrej Uhlik, Andrea L. Foster
By
Geology, Minerals, Energy, and Geophysics Science Center

Compost, plants and endophytes versus metal contamination: Choice of a restoration strategy steers the microbiome in polymetallic mine waste

Finding solutions for the remediation and restoration of abandoned mining areas is of great environmental importance as they pose a risk to ecosystem health. In this study, our aim was to determine how remediation strategies with (i) compost amendment, (ii) planting a metal-tolerant grass Bouteloua curtipendula, and (iii) its inoculation with beneficial endophytes influenced the microbiome of meta
Authors
Martina Kracmarova, Jakub Papik, Ondrej Uhlik, John Freeman, Andrea L. Foster, Mary-Catherine Leewis, Courtney Creamer
By
Geology, Minerals, Energy, and Geophysics Science Center

Chromium in minerals and selected aquifer materials

Between 1952 and 1964, hexavalent chromium, Cr(VI), was released into groundwater from a Pacific Gas and Electric Company (PG&E) compressor station in Hinkley, California, in the western Mojave Desert 80 miles northeast of Los Angeles, California. In 2015, the extent of anthropogenic Cr(VI) in groundwater in Hinkley and Water Valleys was uncertain, but some Cr(VI) in groundwater may be naturally o
Authors
Krishangi D. Groover, John A. Izbicki, William Benzel, Jean Morrison, Andrea L. Foster
By
Water Resources Mission Area, California Water Science Center

Sequestration and reoxidation of chromium in experimental microcosms

Groundwater containing hexavalent chromium, Cr(VI), downgradient from the Pacific Gas and Electric Company (PG&E) Hinkley compressor station in the Mojave Desert, 80 miles northeast of Los Angeles, California, is undergoing bioremediation using added ethanol as a reductant in a volume of the aquifer defined as the in situ reactive zone (IRZ). This treatment reduces Cr(VI) to trivalent chromium, Cr
Authors
Laurence G. Miller, Callum E. Bobb, Andrea L. Foster, Emily G. Wright, Stacy C. Bennett, Krishangi D. Groover, John A. Izbicki
By
Water Resources Mission Area, California Water Science Center

Microbial endophytes and compost improve plant growth in two contrasting types of hard rock mining waste

The re-vegetation of mining wastes with native plants is a comparatively low-cost solution for mine reclamation. However, re-vegetation fails when extreme pH values, low organic matter, or high concentrations of phytotoxic elements inhibit plant establishment and growth. Our aim was to determine whether the combined addition of municipal waste compost and diazotrophic endophytes (i.e., microorgani
Authors
Courtney Creamer, Mary-Catherine Leewis, Francesca C. Governali, John Freeman, Floyd Gray, Emily G. Wright, Andrea L. Foster
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center

Mineralogy dictates the initial mechanism of microbial necromass association

Soil organic matter (SOM) improves soil fertility and mitigates disturbance related to climate and land use change. Microbial necromass (the accumulated cellular residues of microorganisms) comprises the majority of soil C, yet the formation and persistence of necromass in relation to mineralogy is poorly understood. We tested whether soil minerals had different microbial necromass association mec
Authors
Courtney Creamer, Andrea L. Foster, Corey Lawrence, Jack McFarland, Marjorie S. Schulz, Mark Waldrop
By
Ecosystems Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center

Mineralogical characterization of weathered outcrops as a tool for constraining water chemistry predictions during project planning

Weathered samples from naturally exposed outcrops of troctolite associated with a magmatic Ni-Cu sulphide deposit were characterized by synchrotron-based micro-X-ray fluorescence mapping (µ-XRF) and X-ray absorption spectroscopy (XAS), as well as by lab-based X-ray diffraction, electron microscopy, Raman spectroscopy and wet chemical methods. Metal mobility in weathered samples was assessed using
Authors
Tamara Diedrich, Paul Fix, Andrea L. Foster
By
Energy and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center

Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils

It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil. Aluminum and Si were the major elements dissolved from NIST 27
Authors
Christopher T. Mills, Carleton R. Bern, Ruth E. Wolf, Andrea L. Foster, Jean Morrison, William Benzel
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Copper speciation in variably toxic sediments at the Ely Copper Mine, Vermont, United States

At the Ely Copper Mine Superfund site, Cu concentrations exceed background values in both streamwater (160–1200 times) and sediments (15–79 times). Previously, these sediment samples were incubated with laboratory test organisms, and they exhibited variable toxicity for different stream sites. In this study we combined bulk- and microscale techniques to determine Cu speciation and distribution in
Authors
Bryn E. Kimball, Andrea L. Foster, Robert R. Seal, Nadine M. Piatak, Samuel M. Webb, Jane M. Hammarstrom
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Energy & Minerals Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls

Although As concentrations have been investigated in shallow groundwater from the Hetao basin, China, less is known about U and As distributions in deep groundwater, which would help to better understand their origins and fate controls. Two hundred and ninety-nine groundwater samples, 122 sediment samples, and 14 rock samples were taken from the northwest portion of the Hetao basin, and analyzed f
Authors
Huaming Guo, Yongfeng Jia, Richard B. Wanty, Yuxiao Jiang, Weiguang Zhao, Wei Xiu, Jiaxing Shen, Yuan Li, Yongsheng Cao, Yang Wu, Di Zhang, Chao Wei, Yilong Zhang, Wengeng Cao, Andrea L. Foster
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center

Arsenic speciation in solids using X-ray absorption spectroscopy

Synchrotron-based X-ray absorption spectroscopy (XAS) is an in situ, minimally-destructive, element-specific, molecular-scale structural probe that has been employed to study the chemical forms (species) of arsenic (As) in solid and aqueous phases (including rocks, soils, sediment, synthetic compounds, and numerous types of biota including humans) for more than 20 years. Although several excellent
Authors
Andrea L. Foster, Chris S. Kim
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center

Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site, Nevada City, CA

Background A realistic estimation of the health risk of human exposure to solid-phase arsenic (As) derived from historic mining operations is a major challenge to redevelopment of California's famed "Mother Lode" region. Arsenic, a known carcinogen, occurs in multiple solid forms that vary in bioaccessibility. X-ray absorption fine-structure spectroscopy (XAFS) was used to identify and quantify th
Authors
Andrea L. Foster, Roger P. Ashley, James J. Rytuba
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