This child item of the data release contains geochemical and environmental-tracer model inputs, outputs, model results, and a full model archive (model code). Dataset includes environmental-tracer concentrations, modeled recharge conditions (water temperature, excess air), resulting estimated groundwater residence times, and geochemical modeling simulations of aqueous speciation and water-rock interaction. This dataset supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the vicinity of the Captain Jack Superfund Site, Boulder County, Colorado. Data were collected by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency.

This child item of the data release contains geochemical and environmental-tracer model inputs, outputs, model results, and a full model archive (model code). Dataset includes environmental-tracer concentrations, modeled recharge conditions (water temperature, excess air), resulting estimated groundwater residence times, and geochemical modeling simulations of aqueous speciation and water-rock interaction. This dataset supports an integrated hydrogeochemical investigation of solute sources, groundwater recharge processes, and groundwater flow in the vicinity of the Captain Jack Superfund Site, Boulder County, Colorado. Data were collected by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency.

This child item of the data release contains groundwater-level elevation and water-quality data, both collected by contractors to U.S. Environmental Protection Agency (EPA) and later furnished to U.S. Geological Survey (USGS), and water-quality data collected by USGS during 2020. The USGS sampling and analysis resulted in a diverse dataset including major and trace elements, rare earth elements (REE), stable isotopes, radiogenic isotopes, and environmental tracers. This diverse dataset aids in providing a complete hydrologic and geochemical conceptualization of the processes occurring in the mine workings and adjacent groundwater and serves as an example of applications to other sites.

This child item of the data release contains groundwater-level elevation and water-quality data, both collected by contractors to U.S. Environmental Protection Agency (EPA) and later furnished to U.S. Geological Survey (USGS), and water-quality data collected by USGS during 2020. The USGS sampling and analysis resulted in a diverse dataset including major and trace elements, rare earth elements (REE), stable isotopes, radiogenic isotopes, and environmental tracers. This diverse dataset aids in providing a complete hydrologic and geochemical conceptualization of the processes occurring in the mine workings and adjacent groundwater and serves as an example of applications to other sites.

The Captain Jack Superfund site near Ward, Colorado hosts extensive interconnected underground mine workings, which drain via the Big Five Adit. Drainage from the adit has historically been acidic with elevated concentrations of metals. In 2018 the U.S. Environmental Protection Agency (EPA) utilized a subsurface remediation strategy consisting of the installation of a hydraulic bulkhead within the workings to preclude drainage out of the mine. To understand the processes occurring during water impoundment within the mine workings, the U.S. Geological Survey (USGS), in cooperation with EPA, completed water-quality sampling and analysis during 2020 as water was again impounded within the mine workings. The USGS sampling and analysis resulted in a diverse dataset including major and trace elements, rare earth elements (REE), stable isotopes, radiogenic isotopes, and environmental tracers. This diverse dataset aids in providing a complete hydrologic and geochemical conceptualization of the processes occurring in the mine workings and adjacent groundwater, and serves as an example of applications to other sites. This data release contains data pertaining to groundwater-level elevations and water-quality data furnished to USGS by EPA and collected by USGS. Also included are geochemical model input files to simulate aqueous speciation, mineral equilibrium, and groundwater age and mixing as well as output files. Data are provided in child item "Hydrologic and geochemical data" and model input and output files are provided in child item "Geochemical and environmental tracer models".

The U.S. Geological Survey (USGS) used an analytic-element method (AEM) modeling approach to quantitatively understand groundwater dynamics at the Captain Jack Superfund Site, located in Boulder County, Colorado. The Captain Jack Superfund Site hosts extensive interconnected underground mine workings.The U.S. Environmental Protection Agency has instituted a remedial strategy of impounding water within the mine workings behind a hydraulic bulkhead in May 2018. The AEM is a grid-less modeling framework where multiple hydrologic stressors may be superimposed upon one another, resulting in a prediction of the bulk system response. This screening-level model could be used for evaluation of boundary conditions, hydraulic properties, and hydrologic compartmentalization and uses a probabilistic approach wherein uncertainty in multiple boundary conditions and hydraulic properties may be tested. The model is not expected to reproduce all observed water levels exactly, but instead is used to provide a framework for future data collection and modeling. This model archive contains model code, inputs, and example outputs for a single simulated scenario. The AEM for the Captain Jack Superfund Site was constructed in the Python programming language. This USGS data release contains all of the input and output files for the simulations described in the associated journal article (https://doi.org/10.1007/s12665-023-10797-3)

The Wilcox Oil Company Superfund site (hereinafter referred to as “the site”) was formerly an oil refinery in northeast of Bristow in Creek County, Oklahoma. Historical refinery operations contaminated the soil, surface water, streambed sediments, alluvium, and groundwater with refined and stored products at the site. The Wilcox and Lorraine process areas are where the highest concentrations of volatile organic compounds, semivolatile organic compounds, polycyclic aromatic hydrocarbons, and trace elements (including metals) (collectively hereinafter referred to as “contaminants”) were measured in a local shallow perched groundwater system within the alluvium (hereinafter referred to as the “alluvial aquifer”) at the site during previous site assessments. In order to understand the potential migration of contaminants through the soil and groundwater in these areas, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, investigated aquifer characteristics of the alluvial aquifer in the Wilcox and Lorraine process areas of the site to (1) document hydraulic conductivity and other aquifer characteristics of the alluvial aquifer that govern contaminant fate and transport, (2) describe the geospatial extent and concentration of the contaminants in the alluvial aquifer in the Wilcox and Lorraine process areas, and (3) describe the geochemical controls pertaining to oxidation and reduction governing the fate and transport and the degradation potential of contaminants in the groundwater. This data release documents the data that were collected and briefly describes how they were used to characterize the hydrogeologic framework, groundwater-flow system, geochemistry, and aquifer hydraulic properties of the shallow groundwater system. Refer to the companion larger work citation (Teeple and others, 2025) for the complete description and data analyses.

To observe real-time pier scour at three scour-critical sites in Idaho, the U.S. Geological Survey, in cooperation with Idaho Transportation Department, installed and operated fixed real-time (15-minute interval) bed elevation scour sonar sensors at three bridge locations associated with U.S. Geological Survey streamflow gaging stations for water years 2020 through 2022. Observed pier scour data during spring runoff (water years 2020–22) were compared to both Coarse Bed and Hydraulic Engineering Circular 18 (HEC-18) general pier scour design equation estimates to better understand how the observed pier scour data compared to design pier scour equation estimates during the same observational periods. As part of the larger study, site-specific geomorphic data and other observations were collected during a single visit to each bridge. Geomorphic data collected during each visit included a Wolman pebble count (Wolman, 1954) to define the median diameter of the streambed material, an estimate of the flow angle of attack (during peak flow conditions), an assessment of pier shape and dimensions, observations of the floodplain, and observations of bridge scour countermeasures. In addition, a GNSS site survey was completed to update the gage datum water surface elevations and determine the elevation of each bridge structure (road deck and low chord elevations). Real-time (15-minute) hydrologic data were available at each USGS streamflow gaging station (both prior to and during this study) and included real-time discharge and water-surface elevation data (U.S. Geological Survey, 2016, 2024a, 2024b, 2024c). The historic USGS discharge measurement data were used to develop peak flow velocity estimates at each site where the velocity is depth averaged over the cross-section. For each peak flow, the velocity was linearly interpolated using observed measurement data collected from each bridge. Depth for each peak flow condition was computed using the difference between the water surface elevation and the computed channel bed elevation at each site. Geomorphic site surveys provided site specific parameters required for the hydraulic assessment.

Water level, water temperature, and specific conductance data were collected during natural gradient tests on six observation wells screened in the upper transmissive zone of the Ogallala aquifer at the North East 2nd Street Superfund site in Happy, Texas, from November 6-13, 2023. Tests involved gravity draining 100-160 gallons of a low-concentration salt-spiked solution with an associated specific conductance of less than 8,000 microsiemens per centimeter (µs/cm) into the wells, measuring water level responses, and recording continuous downhole water temperature and water conductivity (specific conductance). Gravity drainage of the salt-spiked solution into each well took approximately 1 hour at average rates of 2.4 to 5.2 gallons per minute. Depth profiles of water temperature and specific conductance were collected under ambient conditions (prior to draining the salt-spiked solution into each well). Another depth profile was collected after the salt-spiked solution was added to each well (to identify vertical changes in the water column of the well and the degree of vertical mixing of the spiked water). The single well natural gradient tests allow for the analysis of hydraulic responses of the aquifer during gravity drainage and assessment of ambient flow through the well after the emplacement of the salt-spiked solution and subsequent flushing out of the solution back to ambient conditions. Monitoring at each well continued for at least 24 hours after gravity-drainage of the salt-spiked solution into each well was completed to ascertain whether background conditions were achieved. This data release contains information on the well construction of the six wells tested in 2023 for natural gradient tests, the volume and concentration of the dilute salt spike used, profiles of specific conductance and water temperature of the wells pre- and post-spiked, water levels, and continuous monitoring of specific conductance and water temperature.

There are manual measurements of well construction, hydraulic, and chemical data for several wells from the Stringfellow Superfund site, Jurupa Valley, California. The hydraulic data includes hydraulic head. Chemical data includes physiocochemical data. Physiocochemical profiles of the well water column were done under ambient and post pumped conditions. There are also continuous measurements of hydraulic head, and the monitoring of the presence of tracers (rhodamine, fluorescein, and brilliant blue dye).