U.S. Geological Survey hydrographers preparing the Shavano Park at Fawn Drive site for hydrologic and water-quality monitoring. Located in the Edwards Aquifer, Texas
Stephen Opsahl
Steve is currently a Hydrologist with the Oklahoma-Texas Water Science Center in San Antonio and intends to apply his experiences to help better understand and manage the aquatic network of Texas including watersheds, aquifers, and coastal marine systems.
Steve’s interest in science began at an early age and he could usually be found around water. Steve received a bachelor’s degree in microbiology from the University of Texas at Austin and followed this with a Ph.D. in Marine Science from the U.T. Austin Marine Science Institute in Port Aransas, TX. Steve’s research focuses on natural and anthropogenic tracers in aquatic systems and the influence of UV radiation on both biology and chemistry. While in Georgia, Steve developed an appreciation for aquifers including their importance as an ecosystem and for supporting human life.
Science and Products
Water quality, sources of nitrate, and chemical loadings in the Geronimo Creek and Plum Creek watersheds, south-central Texas, April 2015–March 2016 Water quality, sources of nitrate, and chemical loadings in the Geronimo Creek and Plum Creek watersheds, south-central Texas, April 2015–March 2016
New insights into nitrate dynamics in a karst groundwater system gained from in situ high-frequency optical sensor measurements New insights into nitrate dynamics in a karst groundwater system gained from in situ high-frequency optical sensor measurements
Compounds of emerging concern in the San Antonio River Basin, Texas, 2011–12 Compounds of emerging concern in the San Antonio River Basin, Texas, 2011–12
Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas.
Sediment conditions in the San Antonio River Basin downstream from San Antonio, Texas, 2000-13 Sediment conditions in the San Antonio River Basin downstream from San Antonio, Texas, 2000-13
Characterizing and simulating sediment loads and transport in the lower part of the San Antonio River Basin Characterizing and simulating sediment loads and transport in the lower part of the San Antonio River Basin
Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13 Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13
Sediment characteristics in the San Antonio River Basin downstream from San Antonio, Texas, and at a site on the Guadalupe River downstream from the San Antonio River Basin, 1966-2013 Sediment characteristics in the San Antonio River Basin downstream from San Antonio, Texas, and at a site on the Guadalupe River downstream from the San Antonio River Basin, 1966-2013
Detections, concentrations, and distributional patterns of compounds of emerging concern in the San Antonio River Basin, Texas, 2011-12 Detections, concentrations, and distributional patterns of compounds of emerging concern in the San Antonio River Basin, Texas, 2011-12
Quality of surface-water runoff in selected streams in the San Antonio segment of the Edwards aquifer recharge zone, Bexar County, Texas, 1997-2012 Quality of surface-water runoff in selected streams in the San Antonio segment of the Edwards aquifer recharge zone, Bexar County, Texas, 1997-2012
Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape
Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams
San Antonio River Sediment and Water Quality Monitoring in an Oil and Gas Production Area
Edwards Aquifer Recharge Zone Surface-water and Groundwater Interaction
Urban Waters Federal Partnership - Edwards Aquifer Recharge Zone Monitoring Network
Edwards Aquifer Studies in Texas
U.S. Geological Survey hydrographers preparing the Shavano Park at Fawn Drive site for hydrologic and water-quality monitoring. Located in the Edwards Aquifer, Texas
A drill rig on a drill pad in Karnes County, Texas.
A drill rig on a drill pad in Karnes County, Texas.
Science and Products
Water quality, sources of nitrate, and chemical loadings in the Geronimo Creek and Plum Creek watersheds, south-central Texas, April 2015–March 2016 Water quality, sources of nitrate, and chemical loadings in the Geronimo Creek and Plum Creek watersheds, south-central Texas, April 2015–March 2016
New insights into nitrate dynamics in a karst groundwater system gained from in situ high-frequency optical sensor measurements New insights into nitrate dynamics in a karst groundwater system gained from in situ high-frequency optical sensor measurements
Compounds of emerging concern in the San Antonio River Basin, Texas, 2011–12 Compounds of emerging concern in the San Antonio River Basin, Texas, 2011–12
Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas.
Sediment conditions in the San Antonio River Basin downstream from San Antonio, Texas, 2000-13 Sediment conditions in the San Antonio River Basin downstream from San Antonio, Texas, 2000-13
Characterizing and simulating sediment loads and transport in the lower part of the San Antonio River Basin Characterizing and simulating sediment loads and transport in the lower part of the San Antonio River Basin
Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13 Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13
Sediment characteristics in the San Antonio River Basin downstream from San Antonio, Texas, and at a site on the Guadalupe River downstream from the San Antonio River Basin, 1966-2013 Sediment characteristics in the San Antonio River Basin downstream from San Antonio, Texas, and at a site on the Guadalupe River downstream from the San Antonio River Basin, 1966-2013
Detections, concentrations, and distributional patterns of compounds of emerging concern in the San Antonio River Basin, Texas, 2011-12 Detections, concentrations, and distributional patterns of compounds of emerging concern in the San Antonio River Basin, Texas, 2011-12
Quality of surface-water runoff in selected streams in the San Antonio segment of the Edwards aquifer recharge zone, Bexar County, Texas, 1997-2012 Quality of surface-water runoff in selected streams in the San Antonio segment of the Edwards aquifer recharge zone, Bexar County, Texas, 1997-2012
Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape
Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams
San Antonio River Sediment and Water Quality Monitoring in an Oil and Gas Production Area
Edwards Aquifer Recharge Zone Surface-water and Groundwater Interaction
Urban Waters Federal Partnership - Edwards Aquifer Recharge Zone Monitoring Network
Edwards Aquifer Studies in Texas
U.S. Geological Survey hydrographers preparing the Shavano Park at Fawn Drive site for hydrologic and water-quality monitoring. Located in the Edwards Aquifer, Texas
U.S. Geological Survey hydrographers preparing the Shavano Park at Fawn Drive site for hydrologic and water-quality monitoring. Located in the Edwards Aquifer, Texas
A drill rig on a drill pad in Karnes County, Texas.
A drill rig on a drill pad in Karnes County, Texas.