Rob is a Research Hydrologist with the Colorado Water Science Center
Professional Experience
1992-Present Research Hydrologist, U.S. Geological Survey, Denver, Colorado
1989-1992 Research Engineer, University of Colorado, Center for Advanced Decision Support in Water and Environmental Systems (CADSWES), Boulder, Colorado
1987-1989 Hydrologist, Minnesota Department of Natural Resources, Detroit Lakes, Minnesota
Education and Certifications
Bachelor of Science, Summa Cum Laude, 1985, Computer Science and Environmental Studies, Minnesota State University, Mankato
Master of Environmental Management, 1987, Water Resources, Duke University: Monte Carlo Analysis of the Surface Water Component for Land Disposal Restriction Determinations
Doctor of Philosophy, 1993, Environmental Engineering, University of Colorado: Development and Application of an Equilibrium-based Simulation Model for Reactive Solute Transport in Small Streams
Affiliations and Memberships
Associate Editor, Water Resources Research, 2006–2014
Member, American Geophysical Union
Member, Society for Freshwater Science
Member, European Geosciences Union
Science and Products
Stream discharge, sodium, bromide, and specific conductance data for stream and hyporheic zone samples affected by injection of sodium bromide tracer, Leavenworth Creek, Clear Creek County, Colorado, August 2012
Leavenworth Creek, a tributary of South Clear Creek and Clear Creek near Georgetown, Colorado contains copper, lead, and zinc concentrations that are near to or exceed aquatic life standards. The creek drains the Argentine mining district where mining was active primarily in the early 1900s. In the summer of 2012, the U.S. Geological Survey (USGS) conducted a metal-loading study using tracer dilut
Streamflow and water chemistry in the Tenaya Lake Basin, Yosemite National Park, California
The Tenaya Lake Water Budget Study seeks to quantify and understand the water balance within the principal snow accumulation and runoff yielding zone in the Sierra Nevada Mountains. The Study operates stage sensors and data loggers to record Tenaya Lake inflows, water surface elevation, and outflow, with continuous annual data collection for the 21 square-kilometer watershed located in the alpine
Water quality and discharge data from draining mine tunnels near Silverton, Colorado 1993-2015
The American Tunnel, the Black Hawk mine, the Gold King mine, the Mogul mine, and the Red and Bonita mine are located in the Cement Creek watershed, tributary to the upper Animas River near Silverton, Colorado. All five sites have tunnels that drain groundwater from abandoned underground mine workings to the surface. This draining water has elevated concentrations of metals and degrades water qual
Hydrologic reconnaissance to identify areas of emergent groundwater, Mineral Creek, near Silverton, Colorado, June 2020
Hydrologic reconnaissance of Mineral Creek near Silverton, Colo., was conducted from June 25-27, 2020. Both banks of Mineral Creek and the adjacent hillsides were walked, starting near the ghost town of Chattanooga and proceeding downstream to the confluence of Mineral Creek with the Middle Fork of Mineral Creek. The purpose of this reconnaissance was to identify areas of emergent groundwater on
Synoptic sampling data from Illinois Gulch and Iron Springs near Breckenridge, Colorado, August 2016 and September 2017
Two synoptic sampling campaigns were conducted near Breckenridge, Colorado, to quantify metal loading to Illinois Gulch, a tributary of the Blue River. The first campaign, conducted in August 2016, was designed to determine the degree to which Illinois Gulch loses water to the underlying mine workings, and to determine the effect of these losses on observed metal loads. The second campaign, conduc
Hydrologic, biogeochemical, and radon data collected within and adjacent to the Little Wind River near Riverton, Wyoming
The U.S. Geological Survey is studying the interaction of a contaminated groundwater plume enriched in uranium and other trace elements with water, sediment, and biota along a 3 km reach of the Little Wind River in central Wyoming. The source of the contaminants is from a reclaimed uranium mill site near Riverton, Wyoming. The study is being done in collaboration with the Department of Energy, Uni
Filter Total Items: 66
Quantification of metal loading using tracer dilution and instantaneous synoptic sampling and importance of diel cycling in Leavenworth Creek, Clear Creek County, Colorado, 2012
Leavenworth Creek, a tributary of South Clear Creek and Clear Creek near Georgetown, Colorado, contains copper, lead, and zinc at concentrations close to or in excess of aquatic-life standards. In the summer of 2012, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service and the Colorado Division of Reclamation, Mining and Safety, conducted monitoring to
A simple low-cost approach for transport parameter determination in mountain rivers
A simplified low-cost approach to experimentally determine transport parameters in mountain rivers is described, with an emphasis on the longitudinal dispersion coefficient (DL). The approach is based on a slug injection of table salt (NaCl) as a tracer and specific conductance readings at different locations downstream of the injection spot. Observed specific conductance readings are fit using th
Effects of hydrologic variability and remedial actions on first flush and metal loading from streams draining the Silverton caldera, 1992–2014
This study examined water quality in the upper Animas River watershed, a mined watershed that gained notoriety following the 2015 Gold King mine release of acid mine drainage to downstream communities. Water-quality data were used to evaluate trends in metal concentrations and loads over a two-decade period. Selected sites included three sites on tributary streams and one main-stem site on the Ani
Assessment of a conservative mixing model for the evaluation of constituent behavior below river confluences, Elqui River Basin, Chile
Fate and transport modeling of water-borne contaminants is a data demanding and costly endeavor, requiring considerable expes such, it becomes important to know when a complex modeling approach is required, and when a simpler approach is adequate. This is the main objective herein, where a conservative mixing model is used to characterize the transport of As, Cu, Fe, and SO4. The study area is div
Water-quality change following remediation using structural bulkheads in abandoned draining mines, upper Arkansas River and upper Animas River, Colorado USA
Water-quality effects after remediating abandoned draining mine tunnels using structural bulkheads were examined in two study areas in Colorado, USA. A bulkhead was installed in the Dinero mine tunnel in 2009 to improve water quality in Lake Fork Creek, a tributary to the upper Arkansas River. Although bulkhead installation improved pH, and manganese and zinc concentrations and loads at the Dinero
Critical shifts in trace metal transport and remediation performance under future low river flows
Exceptionally low river flows are predicted to become more frequent and more severe across many global regions as a consequence of climate change. Investigations of trace metal transport dynamics across streamflows reveal stark changes in water chemistry, metal transformation processes, and remediation effectiveness under exceptionally low-flow conditions. High spatial resolution hydrological and
Transport and speciation of uranium in groundwater-surface water systems impacted by legacy milling operations
Growing worldwide concern over uranium contamination of groundwater resources has placed an emphasis on understanding uranium transport dynamics and potential toxicity in groundwater-surface water systems. In this study, we utilized novel in-situ sampling methods to establish the location and magnitude of contaminated groundwater entry into a receiving surface water environment, and to investigate
Exploring the potential of ground-penetrating radar (GPR) to measure the extent of chronic disturbance in peatlands: Examples from acid mine drainage and peat fire
Peatlands are accumulations of partially decayed organic soil that cover approximately 3% of Earth’s surface and have been shown to serve essential environmental and ecological functions such as sequestering carbon, purifying water, and providing habitat for organisms. However, peatlands are threatened by pressures from agriculture, urban development, mining, and climate change. Geophysical method
Cinnamon gulch revisited: Another look at separating natural and mining-impacted contributions to instream metal load
Baseline, premining data for streams draining abandoned mine lands is virtually non existent, and indirect methods for estimating premining conditions are needed to establish realistic, cost effective cleanup goals. One such indirect method is the proximal analog approach, in which premining conditions are estimated using data from nearby mineralized areas that are unaffected by mining. In this pa
Exploration of diffuse and discrete sources of acid mine drainage to a headwater mountain stream in Colorado, USA
We investigated the impact of acid mine drainage (AMD) contamination from the Minnesota Mine, an inactive gold and silver mine, on Lion Creek, a headwater mountain stream near Empire, Colorado. The objective was to map the sources of AMD contamination, including discrete sources visible at the surface and diffuse inputs that were not readily apparent. This was achieved using geochemical sampling,
Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream
Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion Cree
A software tool to assess uncertainty in transient-storage model parameters using Monte Carlo simulations
Researchers and practitioners alike often need to understand and characterize how water and solutes move through a stream in terms of the relative importance of in-stream and near-stream storage and transport processes. In-channel and subsurface storage processes are highly variable in space and time and difficult to measure. Storage estimates are commonly obtained using transient-storage models (
One-Dimensional Transport with Equilibrium Chemistry (OTEQ): A Reactive Transport Model for Streams and Rivers
OTEQ is a mathematical simulation model used to characterize the fate and transport of waterborne solutes in streams and rivers. The model is formed by coupling a solute transport model with a chemical equilibrium submodel. The solute transport model is based on OTIS, a model that considers the physical processes of advection, dispersion, lateral inflow, and transient storage.
One-Dimensional Transport with Inflow and Storage (OTIS): A Solute Transport Model for Streams and Rivers
OTIS is a mathematical simulation model used to characterize the fate and transport of water-borne solutes in streams and rivers.
The governing equation underlying the model is the advection-dispersion equation with additional terms to account for transient storage, lateral inflow, first-order decay, and sorption.
Science and Products
- Data
Stream discharge, sodium, bromide, and specific conductance data for stream and hyporheic zone samples affected by injection of sodium bromide tracer, Leavenworth Creek, Clear Creek County, Colorado, August 2012
Leavenworth Creek, a tributary of South Clear Creek and Clear Creek near Georgetown, Colorado contains copper, lead, and zinc concentrations that are near to or exceed aquatic life standards. The creek drains the Argentine mining district where mining was active primarily in the early 1900s. In the summer of 2012, the U.S. Geological Survey (USGS) conducted a metal-loading study using tracer dilutStreamflow and water chemistry in the Tenaya Lake Basin, Yosemite National Park, California
The Tenaya Lake Water Budget Study seeks to quantify and understand the water balance within the principal snow accumulation and runoff yielding zone in the Sierra Nevada Mountains. The Study operates stage sensors and data loggers to record Tenaya Lake inflows, water surface elevation, and outflow, with continuous annual data collection for the 21 square-kilometer watershed located in the alpineWater quality and discharge data from draining mine tunnels near Silverton, Colorado 1993-2015
The American Tunnel, the Black Hawk mine, the Gold King mine, the Mogul mine, and the Red and Bonita mine are located in the Cement Creek watershed, tributary to the upper Animas River near Silverton, Colorado. All five sites have tunnels that drain groundwater from abandoned underground mine workings to the surface. This draining water has elevated concentrations of metals and degrades water qualHydrologic reconnaissance to identify areas of emergent groundwater, Mineral Creek, near Silverton, Colorado, June 2020
Hydrologic reconnaissance of Mineral Creek near Silverton, Colo., was conducted from June 25-27, 2020. Both banks of Mineral Creek and the adjacent hillsides were walked, starting near the ghost town of Chattanooga and proceeding downstream to the confluence of Mineral Creek with the Middle Fork of Mineral Creek. The purpose of this reconnaissance was to identify areas of emergent groundwater onSynoptic sampling data from Illinois Gulch and Iron Springs near Breckenridge, Colorado, August 2016 and September 2017
Two synoptic sampling campaigns were conducted near Breckenridge, Colorado, to quantify metal loading to Illinois Gulch, a tributary of the Blue River. The first campaign, conducted in August 2016, was designed to determine the degree to which Illinois Gulch loses water to the underlying mine workings, and to determine the effect of these losses on observed metal loads. The second campaign, conducHydrologic, biogeochemical, and radon data collected within and adjacent to the Little Wind River near Riverton, Wyoming
The U.S. Geological Survey is studying the interaction of a contaminated groundwater plume enriched in uranium and other trace elements with water, sediment, and biota along a 3 km reach of the Little Wind River in central Wyoming. The source of the contaminants is from a reclaimed uranium mill site near Riverton, Wyoming. The study is being done in collaboration with the Department of Energy, Uni - Publications
Filter Total Items: 66
Quantification of metal loading using tracer dilution and instantaneous synoptic sampling and importance of diel cycling in Leavenworth Creek, Clear Creek County, Colorado, 2012
Leavenworth Creek, a tributary of South Clear Creek and Clear Creek near Georgetown, Colorado, contains copper, lead, and zinc at concentrations close to or in excess of aquatic-life standards. In the summer of 2012, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service and the Colorado Division of Reclamation, Mining and Safety, conducted monitoring toA simple low-cost approach for transport parameter determination in mountain rivers
A simplified low-cost approach to experimentally determine transport parameters in mountain rivers is described, with an emphasis on the longitudinal dispersion coefficient (DL). The approach is based on a slug injection of table salt (NaCl) as a tracer and specific conductance readings at different locations downstream of the injection spot. Observed specific conductance readings are fit using thEffects of hydrologic variability and remedial actions on first flush and metal loading from streams draining the Silverton caldera, 1992–2014
This study examined water quality in the upper Animas River watershed, a mined watershed that gained notoriety following the 2015 Gold King mine release of acid mine drainage to downstream communities. Water-quality data were used to evaluate trends in metal concentrations and loads over a two-decade period. Selected sites included three sites on tributary streams and one main-stem site on the AniAssessment of a conservative mixing model for the evaluation of constituent behavior below river confluences, Elqui River Basin, Chile
Fate and transport modeling of water-borne contaminants is a data demanding and costly endeavor, requiring considerable expes such, it becomes important to know when a complex modeling approach is required, and when a simpler approach is adequate. This is the main objective herein, where a conservative mixing model is used to characterize the transport of As, Cu, Fe, and SO4. The study area is divWater-quality change following remediation using structural bulkheads in abandoned draining mines, upper Arkansas River and upper Animas River, Colorado USA
Water-quality effects after remediating abandoned draining mine tunnels using structural bulkheads were examined in two study areas in Colorado, USA. A bulkhead was installed in the Dinero mine tunnel in 2009 to improve water quality in Lake Fork Creek, a tributary to the upper Arkansas River. Although bulkhead installation improved pH, and manganese and zinc concentrations and loads at the DineroCritical shifts in trace metal transport and remediation performance under future low river flows
Exceptionally low river flows are predicted to become more frequent and more severe across many global regions as a consequence of climate change. Investigations of trace metal transport dynamics across streamflows reveal stark changes in water chemistry, metal transformation processes, and remediation effectiveness under exceptionally low-flow conditions. High spatial resolution hydrological andTransport and speciation of uranium in groundwater-surface water systems impacted by legacy milling operations
Growing worldwide concern over uranium contamination of groundwater resources has placed an emphasis on understanding uranium transport dynamics and potential toxicity in groundwater-surface water systems. In this study, we utilized novel in-situ sampling methods to establish the location and magnitude of contaminated groundwater entry into a receiving surface water environment, and to investigateExploring the potential of ground-penetrating radar (GPR) to measure the extent of chronic disturbance in peatlands: Examples from acid mine drainage and peat fire
Peatlands are accumulations of partially decayed organic soil that cover approximately 3% of Earth’s surface and have been shown to serve essential environmental and ecological functions such as sequestering carbon, purifying water, and providing habitat for organisms. However, peatlands are threatened by pressures from agriculture, urban development, mining, and climate change. Geophysical methodCinnamon gulch revisited: Another look at separating natural and mining-impacted contributions to instream metal load
Baseline, premining data for streams draining abandoned mine lands is virtually non existent, and indirect methods for estimating premining conditions are needed to establish realistic, cost effective cleanup goals. One such indirect method is the proximal analog approach, in which premining conditions are estimated using data from nearby mineralized areas that are unaffected by mining. In this paExploration of diffuse and discrete sources of acid mine drainage to a headwater mountain stream in Colorado, USA
We investigated the impact of acid mine drainage (AMD) contamination from the Minnesota Mine, an inactive gold and silver mine, on Lion Creek, a headwater mountain stream near Empire, Colorado. The objective was to map the sources of AMD contamination, including discrete sources visible at the surface and diffuse inputs that were not readily apparent. This was achieved using geochemical sampling,Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream
Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion CreeA software tool to assess uncertainty in transient-storage model parameters using Monte Carlo simulations
Researchers and practitioners alike often need to understand and characterize how water and solutes move through a stream in terms of the relative importance of in-stream and near-stream storage and transport processes. In-channel and subsurface storage processes are highly variable in space and time and difficult to measure. Storage estimates are commonly obtained using transient-storage models ( - Software
One-Dimensional Transport with Equilibrium Chemistry (OTEQ): A Reactive Transport Model for Streams and Rivers
OTEQ is a mathematical simulation model used to characterize the fate and transport of waterborne solutes in streams and rivers. The model is formed by coupling a solute transport model with a chemical equilibrium submodel. The solute transport model is based on OTIS, a model that considers the physical processes of advection, dispersion, lateral inflow, and transient storage.
One-Dimensional Transport with Inflow and Storage (OTIS): A Solute Transport Model for Streams and Rivers
OTIS is a mathematical simulation model used to characterize the fate and transport of water-borne solutes in streams and rivers.
The governing equation underlying the model is the advection-dispersion equation with additional terms to account for transient storage, lateral inflow, first-order decay, and sorption.