Samuel (Sam) F Lopez
Sam is a Hydrologist with the Utah Water Science Center. He specializes in contaminant hydrology and synthesis of large datasets to support regional modeling efforts related to water availability and use. He has been with the U.S. Geological Survey since 2021.
Sam has a PhD in geology from the University of Utah and a bachelor's in chemistry from Grinnell College. At the U.S. Geological Survey, he is involved with large regional modeling efforts in the Upper Colorado River and Great Salt Lake basins, compilation of analytical databases for critical minerals throughout the Intermountain West, and contaminant source and cycling studies throughout the Great Basin, particularly at Great Salt Lake.
Education and Certifications
PhD, Geology, University of Utah, 2024
B.A., Chemistry, Grinnell College, 2018 (concentration: Environmental Studies)
Honors and Awards
University of Utah Graduate Research Fellowship recipient (2022); Doyle W. Stephens Scholarship recipient (2022)
Science and Products
Compilation of surface water diversion sites and daily withdrawals for the Upper Colorado River Basin, 1980-2022
This data release contains an inventory of 1,358 major surface water diversion structures with associated daily time series withdrawal records (1980-2022) for structures within the Upper Colorado River and Little Colorado River Basins. Diversion structures were included in this dataset if they were determined to have the capacity to divert water at rates greater than 10 cubic feet per...
Assessment of Mercury, Mercury Stable Isotopes, and Trace Metals in Waters, Sediments, and Biota from Great Salt Lake, Utah
Great Salt Lake (GSL) is a designated Site of Hemispheric Importance for migratory birds by the Western Hemisphere Shorebird Reserve Network. Elevated mercury (Hg) and methylmercury (MeHg) levels related to current inputs and past industrial contamination pose a potential threat to GSL biota, in addition to waterfowl hunters that utilize GSL and surrounding wetland areas. Sediments...
Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA
Great Salt Lake is a critical habitat for migratory birds that is threatened by elevated metal concentrations, including mercury (Hg) and lead (Pb), and is subject to severe hydrologic changes, such as declining lake level. When assessing metal profiles recorded in Great Salt Lake sediment, a large data gap exists regarding the sources of metals within the system, which is complicated by...
Authors
Samuel Francisco Lopez, Sarah Elizabeth Janssen, Michael Tate, Diego P. Fernandez, Christopher B. Anderson, Grace Jane Armstrong, Thomas Charng-Shuen Wang, William T.K. Johnson
Database of surface water diversion sites and daily withdrawals for the upper Colorado River Basin, 1980–2022
The Colorado River drains about 8% of the conterminous United States, provides water for 40 million people, and is one of the most overallocated rivers in the world. As the upper Colorado River Basin (UCOL) contributes an estimated 92% of the total basin natural streamflow, knowledge of the location and amount of surface water withdrawals in the UCOL is important for managing the...
Authors
Samuel Francisco Lopez, Jacob E. Knight, Fred D. Tillman, Melissa D. Masbruch, Daniel Wise, Casey J.R. Jones, Matthew Miller
Non-USGS Publications**
Gustin, M.S., Allen, N., Dunham Cheatham, S.M., Choma, N., Lyman, S.N., Johnson, W., Lopez, S., Russell, A., Mei, E., Magand, O., Dommergue, A., Elgiar, T. 2023 Observations of the chemistry and concentrations of reactive Hg at locations with different ambient air chemistry, Science of the Total Environment, 904, 166184. https://doi.org/10.1016/j.scitotenv.2023.166184
Graham, A.M. Van Helten, S., Wadle, A. Mamrak, E., Morsch, J., Lopez, S., Smith, K. (2023). Mercury transport and methylmercury production in the lower Cedar River (Iowa) floodplain. Frontiers in Environmental Chemistry 4: https://doi.org/10.3389/fenvc.2023.1242813
**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
Compilation of surface water diversion sites and daily withdrawals for the Upper Colorado River Basin, 1980-2022
This data release contains an inventory of 1,358 major surface water diversion structures with associated daily time series withdrawal records (1980-2022) for structures within the Upper Colorado River and Little Colorado River Basins. Diversion structures were included in this dataset if they were determined to have the capacity to divert water at rates greater than 10 cubic feet per...
Assessment of Mercury, Mercury Stable Isotopes, and Trace Metals in Waters, Sediments, and Biota from Great Salt Lake, Utah
Great Salt Lake (GSL) is a designated Site of Hemispheric Importance for migratory birds by the Western Hemisphere Shorebird Reserve Network. Elevated mercury (Hg) and methylmercury (MeHg) levels related to current inputs and past industrial contamination pose a potential threat to GSL biota, in addition to waterfowl hunters that utilize GSL and surrounding wetland areas. Sediments...
Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA
Great Salt Lake is a critical habitat for migratory birds that is threatened by elevated metal concentrations, including mercury (Hg) and lead (Pb), and is subject to severe hydrologic changes, such as declining lake level. When assessing metal profiles recorded in Great Salt Lake sediment, a large data gap exists regarding the sources of metals within the system, which is complicated by...
Authors
Samuel Francisco Lopez, Sarah Elizabeth Janssen, Michael Tate, Diego P. Fernandez, Christopher B. Anderson, Grace Jane Armstrong, Thomas Charng-Shuen Wang, William T.K. Johnson
Database of surface water diversion sites and daily withdrawals for the upper Colorado River Basin, 1980–2022
The Colorado River drains about 8% of the conterminous United States, provides water for 40 million people, and is one of the most overallocated rivers in the world. As the upper Colorado River Basin (UCOL) contributes an estimated 92% of the total basin natural streamflow, knowledge of the location and amount of surface water withdrawals in the UCOL is important for managing the...
Authors
Samuel Francisco Lopez, Jacob E. Knight, Fred D. Tillman, Melissa D. Masbruch, Daniel Wise, Casey J.R. Jones, Matthew Miller
Non-USGS Publications**
Gustin, M.S., Allen, N., Dunham Cheatham, S.M., Choma, N., Lyman, S.N., Johnson, W., Lopez, S., Russell, A., Mei, E., Magand, O., Dommergue, A., Elgiar, T. 2023 Observations of the chemistry and concentrations of reactive Hg at locations with different ambient air chemistry, Science of the Total Environment, 904, 166184. https://doi.org/10.1016/j.scitotenv.2023.166184
Graham, A.M. Van Helten, S., Wadle, A. Mamrak, E., Morsch, J., Lopez, S., Smith, K. (2023). Mercury transport and methylmercury production in the lower Cedar River (Iowa) floodplain. Frontiers in Environmental Chemistry 4: https://doi.org/10.3389/fenvc.2023.1242813
**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.