Steven Phillips (Former Employee)
Science and Products
Filter Total Items: 22
Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08 Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08
The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river...
Authors
Celia Zamora, Randy A. Dahlgren, Charles R. Kratzer, Bryan D. Downing, Ann D. Russell, Peter D. Dileanis, Brian A. Bergamaschi, Steven P. Phillips
Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer
Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field‐scale (apparent) estimated reaction rates and isotopic fractionations and local‐scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical...
Authors
Christopher T. Green, J.K. Bohlke, Barbara A. Bekins, Steven P. Phillips
Groundwater: Pumping and land subsidence Groundwater: Pumping and land subsidence
No abstract available.
Authors
Steven P. Phillips, Devin L. Galloway
Simulations of ground-water flow and particle pathline analysis in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California Simulations of ground-water flow and particle pathline analysis in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California
Shallow ground water in the eastern San Joaquin Valley is affected by high nitrate and uranium concentrations and frequent detections of pesticides and volatile organic compounds (VOC), as a result of ground-water development and intensive agricultural and urban land use. A single public-supply well was selected for intensive study to evaluate the dominant processes affecting the...
Authors
Karen R. Burow, Bryant C. Jurgens, Leon J. Kauffman, Steven P. Phillips, Barbara A. Dalgish, Jennifer L. Shelton
Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California
The transport and fate of agricultural chemicals in a variety of environmental settings is being evaluated as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. One of the locations being evaluated is a 2,700-km2 (square kilometer) regional study area in the northeastern San Joaquin Valley surrounding the city of Modesto, an area dominated by irrigated...
Authors
Steven P. Phillips, Christopher T. Green, Karen R. Burow, Jennifer L. Shelton, Diane L. Rewis
MODGRASS: Update of a ground-water flow model for the central part of the western San Joaquin Valley, California MODGRASS: Update of a ground-water flow model for the central part of the western San Joaquin Valley, California
No abstract available.
Authors
Charles F. Brush, Kenneth Belitz, Steven P. Phillips, Karen R. Burow, Donna L. Knifong
Science and Products
Filter Total Items: 22
Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08 Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08
The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river...
Authors
Celia Zamora, Randy A. Dahlgren, Charles R. Kratzer, Bryan D. Downing, Ann D. Russell, Peter D. Dileanis, Brian A. Bergamaschi, Steven P. Phillips
Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer
Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field‐scale (apparent) estimated reaction rates and isotopic fractionations and local‐scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical...
Authors
Christopher T. Green, J.K. Bohlke, Barbara A. Bekins, Steven P. Phillips
Groundwater: Pumping and land subsidence Groundwater: Pumping and land subsidence
No abstract available.
Authors
Steven P. Phillips, Devin L. Galloway
Simulations of ground-water flow and particle pathline analysis in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California Simulations of ground-water flow and particle pathline analysis in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California
Shallow ground water in the eastern San Joaquin Valley is affected by high nitrate and uranium concentrations and frequent detections of pesticides and volatile organic compounds (VOC), as a result of ground-water development and intensive agricultural and urban land use. A single public-supply well was selected for intensive study to evaluate the dominant processes affecting the...
Authors
Karen R. Burow, Bryant C. Jurgens, Leon J. Kauffman, Steven P. Phillips, Barbara A. Dalgish, Jennifer L. Shelton
Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California
The transport and fate of agricultural chemicals in a variety of environmental settings is being evaluated as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. One of the locations being evaluated is a 2,700-km2 (square kilometer) regional study area in the northeastern San Joaquin Valley surrounding the city of Modesto, an area dominated by irrigated...
Authors
Steven P. Phillips, Christopher T. Green, Karen R. Burow, Jennifer L. Shelton, Diane L. Rewis
MODGRASS: Update of a ground-water flow model for the central part of the western San Joaquin Valley, California MODGRASS: Update of a ground-water flow model for the central part of the western San Joaquin Valley, California
No abstract available.
Authors
Charles F. Brush, Kenneth Belitz, Steven P. Phillips, Karen R. Burow, Donna L. Knifong