Tanya Gallegos is an Associate Program Coordinator, Mineral Resources Program (MRP) in Reston, VA.
Dr. Tanya Gallegos is a research engineer at the U.S. Geological survey and a registered professional engineer in New Mexico. She joined USGS in 2007 as a Mendenhall Post-Doctoral fellow to study the redox chemistry of iron sulfide, arsenic and uranium in uranium mine waters. Her current research encompasses field and lab studies to understand the products, byproducts and wastes from the energy resource life cycles – unconventional oil and shale gas recovery via hydraulic fracturing and uranium recovery via mining and milling. Research topics include: geochemical and isotopic characterization of mine influenced water, oilfield brine, ore, and solid surfaces (gamma spectrometry, SEM, XRD, ICP-OES, ICP-MS EXAFS/XAS); geochemical modeling; integrated assessments for energy resource development; assessing water use in hydraulic fracturing and uranium mining; groundwater restoration at ISR uranium mines; dilute inorganic chemistry; groundwater remediation of trace elements; and naturally occurring radioactive materials (NORM). She is currently managing the Naturally Occurring Radionuclide Lab and the Advancements in Geochemistry and Geomicrobiology of Energy Resources project. She leads three tasks: Developing sensing Methods to Identify Abandoned Mines, Waste as a Resource in Abandoned Mines, and NORM Products in Energy Resource Life Cycles. Tanya also serves on the steering committees for the Federal Remediation Technology Roundtable and the Federal Mining Dialogue and has previously served on the New Mexico Uranium Mining Task Force. She is also an associate editor for Applied Geochemistry. From 2010-2012, she served on the USGS Strategic Science Planning Team for the Energy and Minerals Resource Mission Area.
Work Experience
Research and Applied Engineering Expertise
- Geochemical and isotopic interpretation of unconventional oil and gas produced waters
- Water use in oil and gas production using hydraulic fracturing in the United States
- Water use and groundwater contamination following uranium mining
- Spectroscopic study of nanoscale iron sulfide and uranium reaction products
- Gamma ray spectroscopy for evaluation of naturally occurring radioactive materials (NORM)
- Development of geoenvironmental assessment methodology for uranium mining
- Rock-water-oil interactions during hydraulic fracturing of tight oil plays
- Laboratory studies to understand the redox behavior of iron sulfides, uranium and arsenic
- Geochemical controls on uranium following in-situ uranium recovery (ISR)
- Geochemical and isotopic tracers of elements from uranium mining and hydraulic fracturing
- Characteristics of uranium deposits amenable to situ recovery of uranium in WY and TX
- Civil engineering design of water, wastewater, and drainage systems.
Education and Certifications
University of Michigan, Environmental Engineering/Water Resources, Ph.D.
University of New Mexico, Civil & Environmental Engineering, M.S.
University of New Mexico, Civil Engineering, B.S.
Research Engineering Experience
Research Engineer, U.S. Geological Survey
Post-doctoral Mendenhall Fellow, Research Chemist, U.S. Geological Survey
Teaching, Academia and Scholastic Experience
STEM-Engineering Curriculum Design, New Mexico State University at Grants Community College
Uranium Geochemistry Short Course lecturer; Geochemical Society of America
Public Education: Uranium in the Environment, U.S. Geological Survey science modules for public dissemination
Affiliations and Memberships*
Society for the Advancement of Chicanos and Native Americans in Science (SACNAS)
Geological Society of America (GSA)
American Geophysical Union
Geochemical Society
Science and Products
Remote Sensing Techniques for Characterizing Energy Resources in Waste
NORM Byproducts of Energy Resources
Hydraulic Fracturing and Water Resources: An Assessment of the Potential Effects of Shale Gas Development on Water Resources in the United States
Visible and Near Infrared (VNIR) and Short Wavelength Infrared (SWIR) Spectra of Select Rock Cores and Waste Material from Nine Uranium Mine Sites in Karnes and Live Oak Counties, Texas
Spatial and Temporal Data on Hydraulic Fracturing Fluid Types and Amounts Injected into Oil and Gas Wells Across the U.S., 2015-2019
Absorbance and Fluorescence Excitation-Emission Matrix Data for Produced Waters from Oil and Gas Producing Basins in the United States
Data Compiled on historical water use, spatial land disturbance, aquifer disturbance and uranium produced by In Situ Recovery of Uranium from Sandstone Hosted Uranium Deposits in the South Texas Coastal Plain, USA
Data on Produced Water Quality and Quantities from Hydraulically Fractured Williston Basin Oil Wells
Direct Trace Element Determination in Oil and Gas Produced Waters with Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES): Advantages of High Salinity Tolerance (2019)
Mapping abandoned uranium mine features using Worldview-3 imagery in portions of Karnes, Atascosa and Live Oak Counties, Texas
Geoenvironmental model for roll-type uranium deposits in the Texas Gulf Coast
A novel method for conducting a geoenvironmental assessment of undiscovered ISR-amenable uranium Resources: Proof-of-concept in the Texas Coastal Plain
Dissolved organic matter within oil and gas associated wastewaters from U.S. unconventional petroleum plays: Comparisons and consequences for disposal and reuse
Development and description of a composite hydrogeologic framework for inclusion in a geoenvironmental assessment of undiscovered uranium resources in Pliocene- to Pleistocene-age geologic units of the Texas Coastal Plain
A methodology to assess the historical environmental footprint of in-situ recovery (ISR) of uranium: A demonstration in the Goliad Sand in the Texas Coastal Plain, USA
Method for compiling temporally and spatially aggregated data on hydraulic fracturing—Treatments and wells
Insights on geochemical, isotopic, and volumetric compositions of produced water from hydraulically fractured Williston Basin oil wells
Tracing produced water origins from wells hydraulically fractured with freshwater-based fluids is sometimes predicated on assumptions that (1) each geological formation contains compositionally unique brine and (2) produced water from recently hydraulically fractured wells resembles fresher meteoric water more so than produced water from older wells. These assumptions are not valid in Williston Ba
Conceptual framework and approach for conducting a geoenvironmental assessment of undiscovered uranium resources
Organic compounds in produced waters from the Bakken Formation and Three Forks Formation in the Williston Basin, North Dakota
Direct trace element determination in oil and gas produced waters with inductively coupled plasma - Optical emission spectrometry (ICP-OES): Advantages of high salinity tolerance
Science and Products
- Science
Remote Sensing Techniques for Characterizing Energy Resources in Waste
Funded by the USGS Energy Resource Program “Shark Tank” grant. The goal of this project is to develop a method to use remotely collected satellite and airborne data to ascertain the quantity and quality of waste at abandoned uranium mines to better estimate the resource potential, identify abandoned mines and explore potential applications to other energy resources. This is a collaborative effort...NORM Byproducts of Energy Resources
Naturally Occurring Radioactive Material (NORM) is found in waste produced during the extraction of uranium, phosphate, rare earth elements (REE), coal, oil and gas resources. The focus of this effort is to understand the potential for byproduct recovery of U-235 and Th-232, the fissionable isotopes used to generate nuclear energy from wastes produced during energy resource development. The NORM...Hydraulic Fracturing and Water Resources: An Assessment of the Potential Effects of Shale Gas Development on Water Resources in the United States
Shale gas is a key source of onshore domestic energy for the United States and production of this resource is increasing rapidly. Development and extraction of shale gas requires hydraulic fracturing, which entails horizontal drilling, perforation of steel casing and cement grout using explosive charges, and expansion of fractures using fluids under high pressure. Concern over potential environmen - Data
Visible and Near Infrared (VNIR) and Short Wavelength Infrared (SWIR) Spectra of Select Rock Cores and Waste Material from Nine Uranium Mine Sites in Karnes and Live Oak Counties, Texas
These data represent laboratory reflectance measurements conducted on a suite of sandstone, tuffaceous mudstone and claystone rocks and sediment, which are known host and source materials for roll front Uranium deposits mined throughout the South Texas Coastal Plains. Visible through Near Infrared through Shortwave Infrared (~0.4 - 2.5 microns) reflectance were measured using an artificial light sSpatial and Temporal Data on Hydraulic Fracturing Fluid Types and Amounts Injected into Oil and Gas Wells Across the U.S., 2015-2019
Hydraulic fracturing is a treatment method used to stimulate production from oil and gas wells. Hydraulic fracturing involves injection of treatment fluids mixed with propping agents under high pressure into perforated portions of the wellbore. This method causes the reservoir rocks to fracture and the hydraulic fracturing fluids and propping agents to enter the fractures. Subsequently, the injectAbsorbance and Fluorescence Excitation-Emission Matrix Data for Produced Waters from Oil and Gas Producing Basins in the United States
Waters co-produced during petroleum extraction are normally considered wastes but are also possible resources, especially in water-stressed regions. Produced waters can be chemically complex. High salinity, naturally occurring radioactive materials, and organic substances derived from the producing formation can complicate treatment processes. Rapid screening methods to characterize produced waterData Compiled on historical water use, spatial land disturbance, aquifer disturbance and uranium produced by In Situ Recovery of Uranium from Sandstone Hosted Uranium Deposits in the South Texas Coastal Plain, USA
This data release contains data on historical water use, spatial land disturbance, and spatial aquifer disturbances related to in situ recovery (ISR) uranium extraction per unit of uranium produced. These data were compiled from published and publicly available references including journal articles, government reports, industry reports and company reporting documents for regulatory compliance andData on Produced Water Quality and Quantities from Hydraulically Fractured Williston Basin Oil Wells
This dataset contains compositional data on 17 produced water samples from hydraulically fractured unconventional oil wells completed in the Middle Bakken and Three Forks Formations. The oil wells are located in five different wellfields across the Williston Basin. Specific gravity, conductivity, temperature, pH and oxidation-reduction potential for each sample was measured in the field. Ions (B,Direct Trace Element Determination in Oil and Gas Produced Waters with Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES): Advantages of High Salinity Tolerance (2019)
Waters co-produced during petroleum extraction are the largest waste stream from oil and gas development. Reuse or disposal of these waters is difficult due both to their high salinities, which can greatly exceed 35 g/L (seawater equivalent), and also the sheer volume of wastewater generated, which is estimated at nearly 900 billion gallons per year across the United States. Beyond disposal concer - Multimedia
- Publications
Filter Total Items: 29
Mapping abandoned uranium mine features using Worldview-3 imagery in portions of Karnes, Atascosa and Live Oak Counties, Texas
Worldview-3 (WV3) 16-band multispectral data were used to map exposed bedrock and mine waste piles associated with legacy open-pit mining of sandstone-hosted roll-front uranium deposits along the South Texas Coastal Plain. We used the “spectral hourglass” approach to extract spectral endmembers representative of these features from the image. This approach first requires calibrating the imagery toAuthorsBernard E. Hubbard, Tanya J. Gallegos, Victoria G. StengelGeoenvironmental model for roll-type uranium deposits in the Texas Gulf Coast
Geoenvironmental models were formulated by the U.S. Geological Survey in the 1990s to describe potential environmental effects of extracting different types of ore deposits in different geologic and climatic regions. This paper presents a geoenvironmental model for roll-front (roll-type) uranium deposits in the Texas Coastal Plain. The model reviews descriptive and quantitative information derivedAuthorsKatherine Walton-Day, Johanna Blake, Robert R. Seal, Tanya J. Gallegos, Jean Dupree, Kent D BecherA novel method for conducting a geoenvironmental assessment of undiscovered ISR-amenable uranium Resources: Proof-of-concept in the Texas Coastal Plain
A geoenvironmental assessment methodology was developed to estimate waste quantities and disturbances that could be associated with the extraction of undiscovered uranium resources and identify areas on the landscape where uranium and other constituents of potential concern (COPCs) that may co-occur with uranium deposits in this region are likely to persist, if introduced into the environment. PriAuthorsTanya J. Gallegos, Victoria G. Stengel, Katherine Walton-Day, Johanna Blake, Andrew Teeple, Delbert G Humberson, Steven Cahan, Douglas Yager, Kent D BecherDissolved organic matter within oil and gas associated wastewaters from U.S. unconventional petroleum plays: Comparisons and consequences for disposal and reuse
Wastewater generated during petroleum extraction (produced water) may contain high concentrations of dissolved organics due to their intimate association with organic-rich source rocks, expelled petroleum, and organic additives to fluids used for hydraulic fracturing of unconventional (e.g., shale) reservoirs. Dissolved organic matter (DOM) within produced water represents a challenge for treatmenAuthorsBonnie McDevitt, Aaron M. Jubb, Matthew S. Varonka, Madalyn S. Blondes, Mark A Engle, Tanya J. Gallegos, Jenna L. SheltonDevelopment and description of a composite hydrogeologic framework for inclusion in a geoenvironmental assessment of undiscovered uranium resources in Pliocene- to Pleistocene-age geologic units of the Texas Coastal Plain
A previously completed mineral resources assessment of the Texas Coastal Plain indicated the potential for the future discovery of uranium resources. Geoenvironmental assessments that include the hydrogeologic framework can be used as a tool to understand the potential effects of mining operations. The hydrogeologic framework for this study focused on the composite hydrogeologic unit of the tractAuthorsAndrew Teeple, Kent D Becher, Katherine Walton-Day, Delbert G Humberson, Tanya J. GallegosA methodology to assess the historical environmental footprint of in-situ recovery (ISR) of uranium: A demonstration in the Goliad Sand in the Texas Coastal Plain, USA
In-situ recovery (ISR) has been the only technique used to extract uranium from sandstone-hosted uranium deposits in the Pliocene Goliad Sand in the Texas Coastal Plain. Water plays a crucial role throughout the ISR lifecycle of production and groundwater restoration yet neither the water use nor other environmental footprints have been well documented. The goal of this study is to examine historiAuthorsTanya J. Gallegos, Annie Scott, Victoria G. Stengel, Andrew TeepleMethod for compiling temporally and spatially aggregated data on hydraulic fracturing—Treatments and wells
This report provides a step-by-step method for compiling hydraulic fracturing data in the United States from the IHS Markit, 2019, U.S. Well History and Production Relational Database. Data on hydraulically fractured wells include their location (geologic province, State, county), well type (oil or gas), orientation (directional, horizontal, or vertical), spud date, completion date and the hydraulAuthorsBrian A. Varela, Tanya J. GallegosInsights on geochemical, isotopic, and volumetric compositions of produced water from hydraulically fractured Williston Basin oil wells
Tracing produced water origins from wells hydraulically fractured with freshwater-based fluids is sometimes predicated on assumptions that (1) each geological formation contains compositionally unique brine and (2) produced water from recently hydraulically fractured wells resembles fresher meteoric water more so than produced water from older wells. These assumptions are not valid in Williston Ba
AuthorsTanya J. Gallegos, Colin A. Doolan, Rodney R. Caldwell, Mark A Engle, Matthew S. Varonka, Justin E. Birdwell, Glenn D. Jolly, Tyler B. Coplen, Thomas A. OliverByConceptual framework and approach for conducting a geoenvironmental assessment of undiscovered uranium resources
This report presents a novel conceptual framework and approach for conducting a geologically based environmental assessment, or geoenvironmental assessment, of undiscovered uranium resources within an area likely to contain uranium deposits. The framework is based on a source-to-receptor model that prioritizes the most likely contaminant sources, contaminant pathways, and affected environmental meAuthorsTanya J. Gallegos, Katherine Walton-Day, Robert R. SealOrganic compounds in produced waters from the Bakken Formation and Three Forks Formation in the Williston Basin, North Dakota
The organic composition of produced waters (flowback and formation waters) from the middle member of the Bakken Formation and the Three Forks Formation in the Williston Basin, North Dakota were examined to aid in the remediation of surface contamination and help develop treatment methods for produced-water recycling. Twelve produced water samples were collected from the Bakken and Three Forks FormAuthorsMatthew S. Varonka, Tanya Gallegos, Anne L. Bates, Colin A. Doolan, William H. OremDirect trace element determination in oil and gas produced waters with inductively coupled plasma - Optical emission spectrometry (ICP-OES): Advantages of high salinity tolerance
Waters co-produced during petroleum extraction are the largest waste stream from oil and gas development. Reuse or disposal of these waters is difficult due to their high salinities and the sheer volumes generated. Produced waters may also contain valuable mineral commodities. While an understanding of produced water trace element composition is required for evaluating the associated resource andAuthorsAaron M. Jubb, Mark Engle, Jessica Chenault, Madalyn Blondes, Cloelle G. Danforth, Colin Doolan, Tanya Gallegos, Dan Mueller, Jenna Shelton
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government