Mills, T.J., Mast, M.A., Thomas, J., Keith, G., 2016, Controls on Selenium Distribution and Mobilization in an Irrigated Shallow Groundwater System Underlain by Mancos Shale, Uncompahgre River Basin, Colorado, USA, Science of the Total Environment 566–567 (2016) 1621–1631, http://dx.doi.org/10.1016/j.scitotenv.2016.06.063.
Judith C Thomas
Judith Thomas has been a hydrologist with the U.S. Geological Survey for almost 20 years with expertise in groundwater and water quality. Judith is currently the section chief for Groundwater and Geophysics in the Central Midwest Water Science Center.
Biography
Judith has a B.S. from Purdue University and a M.S. from Indiana University. Judith started her career with the USGS in July 2000 in Middleton, Wisconsin where she worked on various projects in groundwater, surface water, and water quality. In 2006, Judith headed west to join the USGS in Grand Junction, Colorado. Some of Judith's Colorado projects included working in northwest Colorado characterizing groundwater resources in areas of significant energy development for the Bureau of Land Management as well as installing and monitoring a groundwater well network in areas of irrigated Mancos Shale in Delta and Montrose, Colorado.
Science and Products
Date published: December 15, 2015
Status: Active Lower Gunnison River Basin Groundwater Selenium
The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U.S. Geological Survey, in cooperation with the...
Contacts: Judith C Thomas
Date published: September 5, 2009
Status: Completed Piceance Basin Water-Quality Data
As large-scale energy development continues in the Piceance Basin, there is potential for changes in surface-water and groundwater resources. In the southern Piceance Basin, a water task force consisting of numerous local governments, municipalities, and energy companies collectively identified the need for a common data repository. In the northern Piceance Basin, similar efforts were...
Contacts: Judith C Thomas
Attribution: Colorado Water Science Center
Date published: October 1, 2004
Status: Completed Roaring Fork Watershed Water-Quality Data
The Roaring Fork Watershed, located in the Rocky Mountains 150 miles west of Denver, Colorado, has seen rapid development and population growth in recent years.
The USGS, in cooperation with Pitkin County, Colorado Water Conservation District, Ruedi Water and Power Authority, and other local entities, conducted a comprehensive surface- and ground-water resource assessment in the Roaring...
Contacts: Judith C Thomas
Attribution: Colorado Water Science Center
Year Published: 2019
Groundwater quality and hydrology with emphasis on selenium mobilization and transport in the Lower Gunnison River Basin, Colorado, 2012–16
Dissolved selenium is a contaminant of concern in the lower Gunnison River Basin, Colorado. Selenium is naturally present in the Cretaceous Mancos Shale and is leached to groundwater and surface water by irrigation. The groundwater on the east side of the Uncompahgre River in Delta and Montrose Counties is one of the primary sources of selenium...
Thomas, Judith C.; McMahon, Peter B.; Arnold, L. R.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Thomas, J.C., McMahon, P.B., and Arnold, L.R., 2019, Groundwater quality and hydrology with emphasis on selenium mobilization and transport in the lower Gunnison River Basin, Colorado, 2012–16: U.S. Geological Survey Scientific Investigations Report 2019–5029, 69 p., https://doi.org/10.3133/sir20195029.
Year Published: 2018
Groundwater chemistry and water-level elevations in bedrock aquifers of the Piceance and Yellow Creek watersheds, Rio Blanco County, Colorado, 2013–16
The Piceance and Yellow Creek watersheds in Rio Blanco County, Colorado, are known to contain important energy resources (oil shale and natural gas) and mineral resources (nahcolite). The primary sources of fresh groundwater in the Piceance and Yellow Creek watersheds are bedrock aquifers in the Uinta and Green River Formations. The aquifers are...
Thomas, Judith C.; McMahon, Peter B.Attribution: Colorado Water Science Center, Water Resources
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Thomas, J.C., and McMahon, P.B., 2018, Groundwater chemistry and water-level elevations in bedrock aquifers of the Piceance and Yellow Creek watersheds, Rio Blanco County, Colorado, 2013–16: U.S. Geological Survey Scientific Investigations Report 2018–5142, 26 p., https://doi.org/10.3133/sir20185142.
Year Published: 2018
Streamflow and selenium loads during synoptic sampling of the Gunnison River and its tributaries near Delta, Colorado, November 2015
In response to the need for more information about selenium (Se) sources and transport, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, completed a study that characterized Se loads in a reach of the Gunnison River between Delta and Grand Junction, Colo. This report identifies where possible dissolved Se...
Stevens, Michael R.; Leib, Kenneth J.; Thomas, Judith C.; Bauch, Nancy J.; Richards, Rodney J.Attribution: Colorado Water Science Center, Water Resources
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Stevens, M.R., Leib, K.J., Thomas, J.C., Bauch, N.J., and Richards, R.J., 2018, Streamflow and selenium loads during synoptic sampling of the Gunnison River and its tributaries near Delta, Colorado, November 2015: U.S. GeologicalSurvey Scientific Investigations Report 2018–5029, 17 p., https://doi.org/10.3133/sir20185029.
Year Published: 2018
Methane in groundwater from a leaking gas well, Piceance Basin, Colorado, USA
Site-specific and regional analysis of time-series hydrologic and geochemical data collected from 15 monitoring wells in the Piceance Basin indicated that a leaking gas well contaminated shallow groundwater with thermogenic methane. The gas well was drilled in 1956 and plugged and abandoned in 1990. Chemical and isotopic data showed the...
McMahon, Peter B.; Thomas, Judith C.; Crawford, John T.; Dornblaser, Mark M.; Hunt, Andrew G.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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McMahon, P.B., Thomas, J.C., Crawford, J.T., Dornblaser, M.M, Hunt, A.G., 2018. Methane in groundwater from a leaking gas well, Piceance Basin, Colorado, USA. Sci. Total Environ. 634, 791-801.
Year Published: 2017
Response of selenium concentrations in groundwater to seasonal canal leakage, lower Gunnison River Basin, Colorado, 2013
Selenium is a water-quality concern in the lower Gunnison River Basin because irrigation water interacting with seleniferous soils derived from the Mancos Shale Formation has mobilized selenium and increased its concentrations in surface water. Understanding the occurrence of elevated selenium concentrations in groundwater is necessary because...
Linard, J.I.; McMahon, P.B.; Arnold, L.R.; Thomas, J.C.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Linard, J.I., McMahon, P.B., Arnold, L.R., and Thomas, J.C., 2017, Response of selenium concentrations in groundwater to seasonal canal leakage, lower Gunnison River Basin, Colorado, 2013 (ver. 1.1, January 2017): U.S. Geological Survey Scientific Investigations Report 2016–5047, 30 p., http://dx.doi.org/10.3133/sir20165047.
Year Published: 2016
Controls on selenium distribution and mobilization in an irrigated shallow groundwater system underlain by Mancos Shale, Uncompahgre River Basin, Colorado, USA
Elevated selenium (Se) concentrations in surface water and groundwater have become a concern in areas of the Western United States due to the deleterious effects of Se on aquatic ecosystems. Elevated Se concentrations are most prevalent in irrigated alluvial valleys underlain by Se-bearing marine shales where Se can be leached from geologic...
Mills, Taylor J.; Mast, M. Alisa; Thomas, Judith C.; Keith, Gabrielle L.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
Year Published: 2015
Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 2012
Previous studies by the U.S. Geological Survey identified Alkali Flat as an area of groundwater upwelling, with increases in concentrations of total dissolved solids, and streamflow loss, but additional study was needed to better characterize these observations. The U.S. Geological Survey, in cooperation with the Bureau of Land Management, White...
Thomas, Judith C.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Thomas, J.C., 2015, Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 2012: U.S. Geological Survey Scientific Investigations Report 2015–5147, 23 p., http://dx.doi.org/10.3133/sir20155147.
Year Published: 2015
Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2014
The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U...
Thomas, Judith C.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Thomas, J.C., 2015, Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2014: U.S. Geological Survey Data Series 955, 44 p., http://dx.doi.org/10.3133/ds955.
Year Published: 2015
Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2012
The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U...
Thomas, Judith C.; Arnold, L. R.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Thomas, J.C., and Arnold, L.R., 2015, Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2012: U.S. Geological Survey Data Series 923, 29 p., http://dx.doi.org/10.3133/ds923.
Year Published: 2013
Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado
Reliably identifying the effects of energy development on groundwater quality can be difficult because baseline assessments of water quality completed before the onset of energy development are rare and because interactions between hydrocarbon reservoirs and aquifers can be complex, involving both natural and human processes. Groundwater age and...
McMahon, Peter B.; Thomas, Judith C.; Hunt, Andrew G.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
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Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado; 2013; Article; Journal; Environmental Science and Technology; McMahon, Peter B.; Thomas, Judith C.; Hunt, Andrew G.
Year Published: 2013
Chemistry and age of groundwater in bedrock aquifers of the Piceance and Yellow Creek watersheds, Rio Blanco County, Colorado, 2010-12
Fourteen monitoring wells completed in the Uinta and Green River Formations in the Piceance Creek and Yellow Creek watersheds in Rio Blanco County, Colorado, were sampled for chemical, isotopic, and groundwater-age tracers to provide information on the overall groundwater quality, the occurrence and distribution of chemicals that could be related...
McMahon, P.B.; Thomas, J.C.; Hunt, A.G.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
View Citation
Chemistry and age of groundwater in bedrock aquifers of the Piceance and Yellow Creek watersheds, Rio Blanco County, Colorado, 2010-12; 2013; SIR; 2013-5132; McMahon, P. B.; Thomas, J. C.; Hunt, A. G.
Year Published: 2013
Chemistry and age of groundwater in the Piceance structural basin, Rio Blanco county, Colorado, 2010-12
Fourteen monitoring wells were sampled by the U.S. Geological Survey, in cooperation with the Bureau of Land Management, to better understand the chemistry and age of groundwater in the Piceance structural basin in Rio Blanco County, Colorado, and how they may relate to the development of underlying natural-gas reservoirs. Natural gas extraction...
McMahon, Peter B.; Thomas, Judith C.; Hunt, Andrew G.Attribution: Water, Colorado Water Science Center, Water Resources, Colorado, United States of America
View Citation
Chemistry and age of groundwater in the Piceance structural basin, Rio Blanco county, Colorado, 2010-12; 2013; FS; 2013-3047; McMahon, Peter B.; Thomas, Judith C.; Hunt, Andrew G.
Pre-USGS Publications
Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado.
McMahon, P.B., J.C. Thomas, and A.G. Hunt. 2013b. Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado. Environmental Science & Technology 47, no. 4: 13250–13257.
Characterization and Statistical Modeling of Bacterial (Escherichia Coli) Outflows from Watersheds that Discharge into Southern Lake Michigan;
Olyphant, G.A., Thomas, J.C., Whitman, R. L., Harper, D. Characterization and Statistical Modeling of Bacterial (Escherichia Coli) Outflows from Watersheds that Discharge into Southern Lake Michigan; Environmental Monitoring and Assessment 81: 289–300; 2003
Delineation of zones of Contribution for Municipal Wells in Sauk County, Wisconsin
Gotkowitz, M. Zeiler, K.K., Dunning, C.P., Thomas, J.C.; Delineation of zones of Contribution for Municipal Wells in Sauk County, Wisconsin; Wisconsin Open File Report 2002-05; 2002
Monitoring and Statistical Modeling of Bacterially Contaminated Stream-flow at the Outlet of Burns Ditch, South Shore, Lake Michigan, Indiana
Thomas, J.C.; Monitoring and Statistical Modeling of Bacterially Contaminated Stream-flow at the Outlet of Burns Ditch, South Shore, Lake Michigan, Indiana; unpublished Master’s Thesis, Indiana University, Bloomington, IN; June 2001