Douglas Kent
Dr. Douglas Kent is a scientist emeritus with the Earth System Processes Division of the Water Mission Area, U. S. Geological Survey.
Doug Kent received an AA from Pasadena City College, a BA in chemistry from the University of California, San Diego and a PhD from Scripps Institution of Oceanography. He has conducted hydrologic research at the USGS since 1985.
Doug Kent's research at the USGS has focused on processes influencing the mobility of constituents that can affect the availability of water for beneficial use by humans and for sustaining aquatic ecosystems.
Science and Products
Geochemical Signatures of Oil and Gas Wastewater from an Accidental Release Detected in Stream Sediment and Pore Waters Two Years Post Spill
Scientists identified geochemical signatures of wastewater in Blacktail Creek, North Dakota, as a result of a 2015 pipeline leak. They demonstrated that environmental signatures from wastewater spills are persistent within a short (1-3 year) time frame, can enter the creek through subsurface pathways, and can create the potential for extended environmental exposures.
Filter Total Items: 13
Concentrations of Per- and Polyfluoroalkyl Substances (PFAS) and Other Chemical Constituents for Groundwater and Surface-Water Samples on Western Cape Cod, Massachusetts, 2014-2019
Groundwater, surface-water, and associated quality assurance samples were collected downgradient of an abandoned fire training area and wastewater infiltration beds on western Cape Cod, Massachusetts and analyzed for per- and polyfluoroalkyl substances (PFAS) from 2014-2019. Water-quality properties measured at the time of sample collection include pH, specific conductance, temperature...
Longitudinal assessment of per- and polyfluoroalkyl substances and co-occurring inorganic and organic contaminants in Neshaminy Creek, Pennsylvania, November 2021
Per- and polyfluoroalkyl substances (PFAS) and co-occurring inorganic and organic contaminants are widely distributed in the environment and understanding their surface water sources is critical for water resource management. In November 2021, 13 sites were sampled along a stream reach in the Neshaminy Creek basin in southeastern Pennsylvania utilizing a time of travel sampling approach...
Aqueous and solid phases partitioning of elemental constituents associated with Marcellus Shale Energy and Environment Laboratory (MSEEL) gas well produced wastewater, Morgantown, WV, 2016 - 2019
The Marcellus Shale Energy and Environment Laboratory (MSEEL) site is a long-term field site and laboratory at the Northeast Natural Energy LLC (NNE) production facility, adjacent to the Monongahela River, located in western Monongalia County, West Virginia, USA. NNE began drilling two horizontal production wells, MIP (Morgantown Industrial Park) -5H and MIP-3H, in the Marcellus Shale in...
Geochemistry and microbiology data collected to study the effects of oil and gas wastewater dumping on arid lands in New Mexico
The Permian Basin, straddling New Mexico and Texas, is one of the most productive oil and gas (OG) provinces in the United States. OG production yields large volumes of wastewater that contain elevated concentrations of major ions including salts (also referred to as brines), and trace organic and inorganic constituents. These OG wastewaters pose unknown environmental health risks...
By
Water Resources Mission Area, Energy Resources Program, Environmental Health Program, Columbia Environmental Research Center, Geology, Energy & Minerals Science Center, Eastern Energy and Environmental Laboratory (EEEL), Reston Biogeochemical Processes in Groundwater Laboratory, Reston Microbiology Laboratory
Simulating changes in the distribution of ammonium and ammonia versus physical and chemical conditions using PHREEQC with applications to toxicity to fish
Two sets of PHREEQC input and output files are provided that illustrate the distribution of aqueous ammonium and ammonia as a function of physical (temperature) and chemical (pH and solution composition) conditions. One set of simulations calculates the distribution of aqueous ammonia and aqueous ammonium over a range of temperatures and pH values in different solution compositions. The...
Water-Quality Data in and near Groundwater Flow-Through Kettle-Hole Lakes, Western Cape Cod, Massachusetts, 2003 - 2018
This U.S. Geological Survey (USGS) data release provides a comprehensive dataset of water-quality results, physical-parameter measurements, hydrologic measurements, and site information collected to study the nature and extent of water quality along groundwater flow paths adjacent to glacial-kettle lakes on Cape Cod, Massachusetts. Water-quality samples were collected in 2003, 2005, and...
Geochemistry Data for Wastewater Samples Collected at a Separator Tank and from an On-Site Storage Tank at the Marcellus Shale Energy and Environment Laboratory (MSEEL) 2015-2019, Morgantown Industrial Park (MIP), West Virginia (ver. 2.0, May 2023)
This U.S. Geological Survey (USGS) Data Release is focused on the geochemistry of wastewater (including flowback and produced water) samples, co-produced with natural gas, collected from the Marcellus Shale Energy and Environment Laboratory (MSEEL) site. MSEEL is a long-term field site and laboratory at the Northeast Natural Energy LLC (NNE) production facility, adjacent to the...
Data on the Effects of Oil and Gas Wastewater Components on Microbial Community Structure and Function
Oil and gas (OG) wastewaters are commonly disposed of by underground injection and previous research showed that activities at a disposal facility in West Virginia affected stream biogeochemistry and sediment microbial communities downstream from the facility. Microorganisms can control the fate and transport of organic and inorganic components of OG wastewater highlighting the need to...
Chemical Data From 40 Years of Monitoring a Treated-Wastewater Groundwater Plume in a Sand and Gravel Aquifer, Cape Cod, Massachusetts, 1978-2018
This U.S. Geological Survey data release provides a comprehensive dataset of water-quality data and sampling-site characteristics collected in 1978-2018 during a study of the effects of land disposal of treated wastewater on groundwater quality in an unconsolidated sand and gravel aquifer on Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to rapid-infiltration...
Lake Ontario Water Quality and Velocity Transect Data 2015-18
From May of 2015 through September of 2018, water-quality were collected at 178 locations and velocity data were collected along 7 transects from select tributaries, embayments, and nearshore lake locations along New York's Lake Ontario waterfront in support of the Great Lakes Restoration Initiative and the Lakewide Action Management Plan. These data include: depth, velocity magnitude...
Geochemistry Data from Samples Collected in 2015-2017 to study an OG wastewater spill in Blacktail Creek, North Dakota
These metadata sets present the comprehensive geochemical composition of solid and water samples from the site of a 11.4ML (million liters) wastewater spill discovered in January, 2015. Analyses of a pipeline sample (analyses of select analytes), supplied by the North Dakota Department of Health are also included. The spill was near Blacktail Creek, north of Williston, ND. The leak was...
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
The U.S. Geological Survey Toxic Substances Hydrology Program at Cape Cod has been investigating the fate and transport of a treated-wastewater, groundwater contaminant plume. A portion of the contaminated groundwater discharges into Ashumet Pond, a kettle hole, freshwater lake. A study was conducted from June 2013 to June 2015 to document transport, transformation, and discharge of...
Filter Total Items: 53
Prioritizing US Geological Survey science on salinization and salinity in candidate and selected priority river basins
The US Geological Survey (USGS) is selecting and prioritizing basins, known as Integrated Water Science basins, for monitoring and intensive study. Previous efforts to aid in this selection process include a scientifically defensible and quantitative assessment of basins facing human-caused water resource challenges (Van Metre et al. in Environmental Monitoring and Assessment, 192(7)...
Authors
Christopher H. Conaway, Nancy T. Baker, Craig J. Brown, Christopher T. Green, Douglas B. Kent
Spatial, seasonal, and diel controls of nitrogen-carbon-oxygen cycling during lake-water infiltration to an aquifer
Many freshwater lakes are groundwater flow-through systems. Although lakes commonly are considered to be sinks for nitrogen inputs, relatively little is known about carbon and nitrogen export from lakes to groundwater. The current study focused on lake-bottom biogeochemical processes accompanying the transport of nitrogen, dissolved oxygen (O2), and dissolved organic carbon (DOC) during...
Authors
Richard L. Smith, Deborah A. Repert, Jennifer C. Underwood, J.K. Böhlke, Denis R. LeBlanc, Robert B. Hull, Douglas B. Kent, Stanley J. Mroczkowski, Ariel Reed
Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses
This report describes scientific gaps that limit our ability to predict water-quality effects on water availability for beneficial uses across the United States. Water-quality constituents considered in the report include salinity, geogenic constituents, contaminants of emerging concern, and nitrogen. For each constituent, there is a selection of scientific gaps, approaches, and outcomes...
Prioritizing water availability study settings to address geogenic contaminants and related societal factors
Water availability for human and ecological uses depends on both water quantity and water quality. The U.S. Geological Survey (USGS) is developing strategies for prioritizing regional-scale and watershed basin-scale studies of water availability across the nation. Previous USGS ranking processes for basin-scale studies incorporated primarily water quantity factors but are now considering...
Authors
Melinda L. Erickson, Craig J. Brown, Elizabeth J. Tomaszewski, Joseph D. Ayotte, Sharon L. Qi, Douglas B. Kent, J.K. Böhlke
Illegal dumping of oil and gas wastewater alters arid soil microbial communities
The Permian Basin, underlying southeast New Mexico and west Texas, is one of the most productive oil and gas (OG) provinces in the United States. Oil and gas production yields large volumes of wastewater with complex chemistries, and the environmental health risks posed by these OG wastewaters on sensitive desert ecosystems are poorly understood. Starting in November 2017, 39 illegal...
Authors
Mitra Kashani, Mark A Engle, Douglas B. Kent, Terry G. Gregston, Isabelle M. Cozzarelli, Adam Mumford, Matthew S. Varonka, Cassandra Rashan Harris, Denise M. Akob
By
Water Resources Mission Area, Contaminant Biology, Energy Resources Program, Environmental Health Program, Toxic Substances Hydrology, Earth Resources Observation and Science (EROS) Center , Geology, Energy & Minerals Science Center, Reston Biogeochemical Processes in Groundwater Laboratory, Reston Microbiology Laboratory
Ammonia and aquatic ecosystems – A review of global sources, biogeochemical cycling, and effects on fish
The purpose of this review is to better understand the full life cycle and influence of ammonia from an aquatic biology perspective. While ammonia has toxic properties in water and air, it also plays a central role in the biogeochemical nitrogen (N) cycle and regulates mechanisms of normal and abnormal fish physiology. Additionally, as the second most synthesized chemical on Earth...
Authors
Thea M. Edwards, Holly J. Puglis, Jonathan Lopez Duran, Lillian Bradshaw, Douglas B. Kent, Aida Farag
Using biological responses to monitor freshwater post-spill conditions over 3 years in Blacktail Creek, North Dakota, USA
A pipeline carrying unconventional oil and gas (OG) wastewater spilled approximately 11 million liters of wastewater into Blacktail Creek, North Dakota, USA. Flow of the mix of stream water and wastewater down the channel resulted in storage of contaminants in the hyporheic zone and along the banks, providing a long-term source of wastewater constituents to the stream. A multi-level...
Authors
Aida Farag, David Harper, Isabelle M. Cozzarelli, Douglas B. Kent, Adam Mumford, Denise M. Akob, Travis W. Schaeffer, Luke R. Iwanowicz
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center, Earth Resources Observation and Science (EROS) Center , Eastern Ecological Science Center, Geology, Energy & Minerals Science Center, Reston Microbiology Laboratory
Integrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Concerns related to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sources of drinking water and in natural and engineered environments have captured national attention over the last few decades. This report provides an overview of the science gaps that exist in the fields of study related to PFAS that are relevant to the U.S. Geological Survey mission and identifies...
Authors
Andrea K. Tokranov, Paul M. Bradley, Michael J. Focazio, Douglas B. Kent, Denis R. LeBlanc, Jeff W. McCoy, Kelly L. Smalling, Jeffery A. Steevens, Patricia L. Toccalino
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be key markers of OG wastewater releases...
Authors
Isabelle M. Cozzarelli, Douglas B. Kent, Martin A. Briggs, Mark A Engle, Adam Benthem, Katherine Skalak, Adam Mumford, Jeanne B. Jaeschke, Aida Farag, John W. Lane, Denise M. Akob
Reactive transport modeling to understand attenuation of arsenic concentrations in anoxic groundwater during Fe(II) oxidation by nitrate
A previously published field-experimental investigation showed that injection of nitrate in anoxic groundwater that contained aqueous and sediment-bound Fe(II) diminished concentrations of As(V) and As(III) to below drinking-water limits. In the current study, reactive transport modeling confirmed that the observed attenuation was consistent with oxidation of Fe(II) by nitrate, leading...
Authors
Douglas B. Kent, Richard L. Smith, James Jamieson, J.K. Böhlke, Deborah A. Repert, Henning Prommer
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater-lake interface are complex and difficult to resolve. In this study, hydrograph variations in a groundwater flow-through lake altered discharge patterns of a wastewater-derived...
Authors
Richard L. Smith, Deborah A. Repert, Deborah Stoliker, Douglas B. Kent, Bongkeun Song, Denis R. LeBlanc, Timothy McCobb, J.K. Böhlke, Sung Pil Hyun, Hee Sun Moon
When oil and water mix: Understanding the environmental impacts of shale development
Development of shale gas and tight oil, or unconventional oil and gas (UOG), has dramatically increased domestic energy production in the U.S. UOG resources are typically developed through the use of hydraulic fracturing, which creates high-permeability flow paths into large volumes of tight rocks to provide a means for hydrocarbons to move to a wellbore. This process uses significant...
Authors
Daniel J. Soeder, Douglas B. Kent
Non-USGS Publications**
Kent, D. B., and Kastner, M., 1985, Mg2+ removal in the system Mg2+‑amorphous SiO2‑H2O by adsorption and Mg‑hydroxysilicate precipitation: Geochimica et Cosmochimica Acta, v. 49, p. 1123‑1136.
Kent, D. B., 1983, On the surface chemical properties of synthetic and biogenic amorphous silica: Ph.D. dissertation, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, 420 pp.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Geochemical Signatures of Oil and Gas Wastewater from an Accidental Release Detected in Stream Sediment and Pore Waters Two Years Post Spill
Scientists identified geochemical signatures of wastewater in Blacktail Creek, North Dakota, as a result of a 2015 pipeline leak. They demonstrated that environmental signatures from wastewater spills are persistent within a short (1-3 year) time frame, can enter the creek through subsurface pathways, and can create the potential for extended environmental exposures.
Filter Total Items: 13
Concentrations of Per- and Polyfluoroalkyl Substances (PFAS) and Other Chemical Constituents for Groundwater and Surface-Water Samples on Western Cape Cod, Massachusetts, 2014-2019
Groundwater, surface-water, and associated quality assurance samples were collected downgradient of an abandoned fire training area and wastewater infiltration beds on western Cape Cod, Massachusetts and analyzed for per- and polyfluoroalkyl substances (PFAS) from 2014-2019. Water-quality properties measured at the time of sample collection include pH, specific conductance, temperature...
Longitudinal assessment of per- and polyfluoroalkyl substances and co-occurring inorganic and organic contaminants in Neshaminy Creek, Pennsylvania, November 2021
Per- and polyfluoroalkyl substances (PFAS) and co-occurring inorganic and organic contaminants are widely distributed in the environment and understanding their surface water sources is critical for water resource management. In November 2021, 13 sites were sampled along a stream reach in the Neshaminy Creek basin in southeastern Pennsylvania utilizing a time of travel sampling approach...
Aqueous and solid phases partitioning of elemental constituents associated with Marcellus Shale Energy and Environment Laboratory (MSEEL) gas well produced wastewater, Morgantown, WV, 2016 - 2019
The Marcellus Shale Energy and Environment Laboratory (MSEEL) site is a long-term field site and laboratory at the Northeast Natural Energy LLC (NNE) production facility, adjacent to the Monongahela River, located in western Monongalia County, West Virginia, USA. NNE began drilling two horizontal production wells, MIP (Morgantown Industrial Park) -5H and MIP-3H, in the Marcellus Shale in...
Geochemistry and microbiology data collected to study the effects of oil and gas wastewater dumping on arid lands in New Mexico
The Permian Basin, straddling New Mexico and Texas, is one of the most productive oil and gas (OG) provinces in the United States. OG production yields large volumes of wastewater that contain elevated concentrations of major ions including salts (also referred to as brines), and trace organic and inorganic constituents. These OG wastewaters pose unknown environmental health risks...
By
Water Resources Mission Area, Energy Resources Program, Environmental Health Program, Columbia Environmental Research Center, Geology, Energy & Minerals Science Center, Eastern Energy and Environmental Laboratory (EEEL), Reston Biogeochemical Processes in Groundwater Laboratory, Reston Microbiology Laboratory
Simulating changes in the distribution of ammonium and ammonia versus physical and chemical conditions using PHREEQC with applications to toxicity to fish
Two sets of PHREEQC input and output files are provided that illustrate the distribution of aqueous ammonium and ammonia as a function of physical (temperature) and chemical (pH and solution composition) conditions. One set of simulations calculates the distribution of aqueous ammonia and aqueous ammonium over a range of temperatures and pH values in different solution compositions. The...
Water-Quality Data in and near Groundwater Flow-Through Kettle-Hole Lakes, Western Cape Cod, Massachusetts, 2003 - 2018
This U.S. Geological Survey (USGS) data release provides a comprehensive dataset of water-quality results, physical-parameter measurements, hydrologic measurements, and site information collected to study the nature and extent of water quality along groundwater flow paths adjacent to glacial-kettle lakes on Cape Cod, Massachusetts. Water-quality samples were collected in 2003, 2005, and...
Geochemistry Data for Wastewater Samples Collected at a Separator Tank and from an On-Site Storage Tank at the Marcellus Shale Energy and Environment Laboratory (MSEEL) 2015-2019, Morgantown Industrial Park (MIP), West Virginia (ver. 2.0, May 2023)
This U.S. Geological Survey (USGS) Data Release is focused on the geochemistry of wastewater (including flowback and produced water) samples, co-produced with natural gas, collected from the Marcellus Shale Energy and Environment Laboratory (MSEEL) site. MSEEL is a long-term field site and laboratory at the Northeast Natural Energy LLC (NNE) production facility, adjacent to the...
Data on the Effects of Oil and Gas Wastewater Components on Microbial Community Structure and Function
Oil and gas (OG) wastewaters are commonly disposed of by underground injection and previous research showed that activities at a disposal facility in West Virginia affected stream biogeochemistry and sediment microbial communities downstream from the facility. Microorganisms can control the fate and transport of organic and inorganic components of OG wastewater highlighting the need to...
Chemical Data From 40 Years of Monitoring a Treated-Wastewater Groundwater Plume in a Sand and Gravel Aquifer, Cape Cod, Massachusetts, 1978-2018
This U.S. Geological Survey data release provides a comprehensive dataset of water-quality data and sampling-site characteristics collected in 1978-2018 during a study of the effects of land disposal of treated wastewater on groundwater quality in an unconsolidated sand and gravel aquifer on Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to rapid-infiltration...
Lake Ontario Water Quality and Velocity Transect Data 2015-18
From May of 2015 through September of 2018, water-quality were collected at 178 locations and velocity data were collected along 7 transects from select tributaries, embayments, and nearshore lake locations along New York's Lake Ontario waterfront in support of the Great Lakes Restoration Initiative and the Lakewide Action Management Plan. These data include: depth, velocity magnitude...
Geochemistry Data from Samples Collected in 2015-2017 to study an OG wastewater spill in Blacktail Creek, North Dakota
These metadata sets present the comprehensive geochemical composition of solid and water samples from the site of a 11.4ML (million liters) wastewater spill discovered in January, 2015. Analyses of a pipeline sample (analyses of select analytes), supplied by the North Dakota Department of Health are also included. The spill was near Blacktail Creek, north of Williston, ND. The leak was...
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
The U.S. Geological Survey Toxic Substances Hydrology Program at Cape Cod has been investigating the fate and transport of a treated-wastewater, groundwater contaminant plume. A portion of the contaminated groundwater discharges into Ashumet Pond, a kettle hole, freshwater lake. A study was conducted from June 2013 to June 2015 to document transport, transformation, and discharge of...
Filter Total Items: 53
Prioritizing US Geological Survey science on salinization and salinity in candidate and selected priority river basins
The US Geological Survey (USGS) is selecting and prioritizing basins, known as Integrated Water Science basins, for monitoring and intensive study. Previous efforts to aid in this selection process include a scientifically defensible and quantitative assessment of basins facing human-caused water resource challenges (Van Metre et al. in Environmental Monitoring and Assessment, 192(7)...
Authors
Christopher H. Conaway, Nancy T. Baker, Craig J. Brown, Christopher T. Green, Douglas B. Kent
Spatial, seasonal, and diel controls of nitrogen-carbon-oxygen cycling during lake-water infiltration to an aquifer
Many freshwater lakes are groundwater flow-through systems. Although lakes commonly are considered to be sinks for nitrogen inputs, relatively little is known about carbon and nitrogen export from lakes to groundwater. The current study focused on lake-bottom biogeochemical processes accompanying the transport of nitrogen, dissolved oxygen (O2), and dissolved organic carbon (DOC) during...
Authors
Richard L. Smith, Deborah A. Repert, Jennifer C. Underwood, J.K. Böhlke, Denis R. LeBlanc, Robert B. Hull, Douglas B. Kent, Stanley J. Mroczkowski, Ariel Reed
Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses
This report describes scientific gaps that limit our ability to predict water-quality effects on water availability for beneficial uses across the United States. Water-quality constituents considered in the report include salinity, geogenic constituents, contaminants of emerging concern, and nitrogen. For each constituent, there is a selection of scientific gaps, approaches, and outcomes...
Prioritizing water availability study settings to address geogenic contaminants and related societal factors
Water availability for human and ecological uses depends on both water quantity and water quality. The U.S. Geological Survey (USGS) is developing strategies for prioritizing regional-scale and watershed basin-scale studies of water availability across the nation. Previous USGS ranking processes for basin-scale studies incorporated primarily water quantity factors but are now considering...
Authors
Melinda L. Erickson, Craig J. Brown, Elizabeth J. Tomaszewski, Joseph D. Ayotte, Sharon L. Qi, Douglas B. Kent, J.K. Böhlke
Illegal dumping of oil and gas wastewater alters arid soil microbial communities
The Permian Basin, underlying southeast New Mexico and west Texas, is one of the most productive oil and gas (OG) provinces in the United States. Oil and gas production yields large volumes of wastewater with complex chemistries, and the environmental health risks posed by these OG wastewaters on sensitive desert ecosystems are poorly understood. Starting in November 2017, 39 illegal...
Authors
Mitra Kashani, Mark A Engle, Douglas B. Kent, Terry G. Gregston, Isabelle M. Cozzarelli, Adam Mumford, Matthew S. Varonka, Cassandra Rashan Harris, Denise M. Akob
By
Water Resources Mission Area, Contaminant Biology, Energy Resources Program, Environmental Health Program, Toxic Substances Hydrology, Earth Resources Observation and Science (EROS) Center , Geology, Energy & Minerals Science Center, Reston Biogeochemical Processes in Groundwater Laboratory, Reston Microbiology Laboratory
Ammonia and aquatic ecosystems – A review of global sources, biogeochemical cycling, and effects on fish
The purpose of this review is to better understand the full life cycle and influence of ammonia from an aquatic biology perspective. While ammonia has toxic properties in water and air, it also plays a central role in the biogeochemical nitrogen (N) cycle and regulates mechanisms of normal and abnormal fish physiology. Additionally, as the second most synthesized chemical on Earth...
Authors
Thea M. Edwards, Holly J. Puglis, Jonathan Lopez Duran, Lillian Bradshaw, Douglas B. Kent, Aida Farag
Using biological responses to monitor freshwater post-spill conditions over 3 years in Blacktail Creek, North Dakota, USA
A pipeline carrying unconventional oil and gas (OG) wastewater spilled approximately 11 million liters of wastewater into Blacktail Creek, North Dakota, USA. Flow of the mix of stream water and wastewater down the channel resulted in storage of contaminants in the hyporheic zone and along the banks, providing a long-term source of wastewater constituents to the stream. A multi-level...
Authors
Aida Farag, David Harper, Isabelle M. Cozzarelli, Douglas B. Kent, Adam Mumford, Denise M. Akob, Travis W. Schaeffer, Luke R. Iwanowicz
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center, Earth Resources Observation and Science (EROS) Center , Eastern Ecological Science Center, Geology, Energy & Minerals Science Center, Reston Microbiology Laboratory
Integrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Concerns related to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sources of drinking water and in natural and engineered environments have captured national attention over the last few decades. This report provides an overview of the science gaps that exist in the fields of study related to PFAS that are relevant to the U.S. Geological Survey mission and identifies...
Authors
Andrea K. Tokranov, Paul M. Bradley, Michael J. Focazio, Douglas B. Kent, Denis R. LeBlanc, Jeff W. McCoy, Kelly L. Smalling, Jeffery A. Steevens, Patricia L. Toccalino
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be key markers of OG wastewater releases...
Authors
Isabelle M. Cozzarelli, Douglas B. Kent, Martin A. Briggs, Mark A Engle, Adam Benthem, Katherine Skalak, Adam Mumford, Jeanne B. Jaeschke, Aida Farag, John W. Lane, Denise M. Akob
Reactive transport modeling to understand attenuation of arsenic concentrations in anoxic groundwater during Fe(II) oxidation by nitrate
A previously published field-experimental investigation showed that injection of nitrate in anoxic groundwater that contained aqueous and sediment-bound Fe(II) diminished concentrations of As(V) and As(III) to below drinking-water limits. In the current study, reactive transport modeling confirmed that the observed attenuation was consistent with oxidation of Fe(II) by nitrate, leading...
Authors
Douglas B. Kent, Richard L. Smith, James Jamieson, J.K. Böhlke, Deborah A. Repert, Henning Prommer
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater-lake interface are complex and difficult to resolve. In this study, hydrograph variations in a groundwater flow-through lake altered discharge patterns of a wastewater-derived...
Authors
Richard L. Smith, Deborah A. Repert, Deborah Stoliker, Douglas B. Kent, Bongkeun Song, Denis R. LeBlanc, Timothy McCobb, J.K. Böhlke, Sung Pil Hyun, Hee Sun Moon
When oil and water mix: Understanding the environmental impacts of shale development
Development of shale gas and tight oil, or unconventional oil and gas (UOG), has dramatically increased domestic energy production in the U.S. UOG resources are typically developed through the use of hydraulic fracturing, which creates high-permeability flow paths into large volumes of tight rocks to provide a means for hydrocarbons to move to a wellbore. This process uses significant...
Authors
Daniel J. Soeder, Douglas B. Kent
Non-USGS Publications**
Kent, D. B., and Kastner, M., 1985, Mg2+ removal in the system Mg2+‑amorphous SiO2‑H2O by adsorption and Mg‑hydroxysilicate precipitation: Geochimica et Cosmochimica Acta, v. 49, p. 1123‑1136.
Kent, D. B., 1983, On the surface chemical properties of synthetic and biogenic amorphous silica: Ph.D. dissertation, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, 420 pp.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.