This data release supports the following publication: Mast, M. A., 2018, Estimating metal concentrations with regression analysis and water-quality surrogates at nine sites on the Animas and San Juan Rivers, Colorado, New Mexico, and Utah: U.S. Geological Survey Scientific Investigations Report 2018-5116. The U.S. Geological Survey (USGS), in cooperation with the U. S. Environmental Protection Agency (EPA), developed site-specific regression models to estimate concentrations of selected metals at nine USGS streamflow-gaging stations along the Animas and San Juan Rivers. Multiple linear-regression models were developed by relating metal concentrations in discrete water-quality samples to continuously monitored streamflow and surrogate parameters including specific conductance, pH, turbidity, and water temperature. Models were developed for dissolved and total concentrations of aluminum, arsenic, cadmium, iron, lead, manganese, and zinc using water-quality samples collected during 2005–17 by several agencies, using different collection methods and analytical laboratories. Calibration datasets in comma-separated format (CSV) include the variables of sampling date and time, metal concentrations (in micrograms per liter), stream discharge (in cubic feet per second), specific conductance (in microsiemens per centimeter at 25 degrees Celsius), pH, water temperature (in degrees Celsius), turbidity (in nephelometric turbidity units), and calculated seasonal terms based on Julian day. Surrogate parameters and discrete water-quality samples were used from nine sites including Cement Creek at Silverton, Colo. (USGS station 09358550); Animas River below Silverton, Colo. (USGS station 09359020); Animas River at Durango, Colo. (USGS station 09361500); Animas River Near Cedar Hill, N. Mex. (USGS station 09363500); Animas River below Aztec, N. Mex. (USGS station 09364010); San Juan River at Farmington, N. Mex. (USGS station 09365000); San Juan River at Shiprock, N. Mex (USGS Station 09368000); San Juan River at Four Corners, Colo. (USGS station 09371010); and San Juan River near Bluff, Utah (USGS station 09379500). Model archive summaries in pdf format include model statistics, data, and plots and were generated using a R script developed by USGS Kansas Water Science Center available at https://patrickeslick.github.io/ModelArchiveSummary/. A description of each USGS streamflow gaging station along with information about the calibration datasets also are provided.

This data release supports the following publication: Mast, M. A., 2018, Estimating metal concentrations with regression analysis and water-quality surrogates at nine sites on the Animas and San Juan Rivers, Colorado, New Mexico, and Utah: U.S. Geological Survey Scientific Investigations Report 2018-5116. The U.S. Geological Survey (USGS), in cooperation with the U. S. Environmental Protection Agency (EPA), developed site-specific regression models to estimate concentrations of selected metals at nine USGS streamflow-gaging stations along the Animas and San Juan Rivers. Multiple linear-regression models were developed by relating metal concentrations in discrete water-quality samples to continuously monitored streamflow and surrogate parameters including specific conductance, pH, turbidity, and water temperature. Models were developed for dissolved and total concentrations of aluminum, arsenic, cadmium, iron, lead, manganese, and zinc using water-quality samples collected during 2005–17 by several agencies, using different collection methods and analytical laboratories. Calibration datasets in comma-separated format (CSV) include the variables of sampling date and time, metal concentrations (in micrograms per liter), stream discharge (in cubic feet per second), specific conductance (in microsiemens per centimeter at 25 degrees Celsius), pH, water temperature (in degrees Celsius), turbidity (in nephelometric turbidity units), and calculated seasonal terms based on Julian day. Surrogate parameters and discrete water-quality samples were used from nine sites including Cement Creek at Silverton, Colo. (USGS station 09358550); Animas River below Silverton, Colo. (USGS station 09359020); Animas River at Durango, Colo. (USGS station 09361500); Animas River Near Cedar Hill, N. Mex. (USGS station 09363500); Animas River below Aztec, N. Mex. (USGS station 09364010); San Juan River at Farmington, N. Mex. (USGS station 09365000); San Juan River at Shiprock, N. Mex (USGS Station 09368000); San Juan River at Four Corners, Colo. (USGS station 09371010); and San Juan River near Bluff, Utah (USGS station 09379500). Model archive summaries in pdf format include model statistics, data, and plots and were generated using a R script developed by USGS Kansas Water Science Center available at https://patrickeslick.github.io/ModelArchiveSummary/. A description of each USGS streamflow gaging station along with information about the calibration datasets also are provided.

A synoptic sampling campaign was conducted on the Animas River near Silverton, Colorado, under low flow conditions in September 2021. The sampling campaign was designed to quantify constituent loading and identify sources of contamination along a 3.8-kilometer study reach. The study reach began approximately 170 meters upstream of Arrastra Creek and extended downstream to U.S. Geological Survey (USGS) gage 09358000 within the city of Silverton, Colorado. A continuous, instream injection of a sodium bromide tracer was initiated at the head of the study reach three days prior to the start of the sampling campaign and maintained until the completion of main stem sampling. Bromide concentrations were subsequently used to determine streamflow using the tracer-dilution method. Water quality samples were collected at 23 sites along the Animas River main stem, and 28 inflow sites including springs, seeps, small tributaries, and ponded water. Main stem sites were sampled using three sampling approaches. Under the first approach, a subset of 8 main stem sites were sampled "simultaneously" (in less than 20 minutes) to assess the effects of diel variation in constituent concentration. Under the second approach, all main stem sites were sampled with the sampling team working in the downstream-to-upstream direction, a protocol typically used during synoptic sampling. A subset of 5 main stem sites were also sampled using an Equal Discharge Increment approach that was designed to indicate which side of the stream was responsible for the observed constituent loads. This data release includes field parameters (water temperature, pH, and specific conductivity), concentration data (inorganic cations and anions), estimated streamflow, and calculated loads for the sampling campaign. Calculated loads may be used to identify and rank sources of contamination to the Animas River. The data release consists of a kmz file showing site locations and the following 3 tables: Table 1, Locations of sampling sites Table 2, Synoptic sampling results, September 20-21, 2021 Table 3, Spatial profiles of streamflow and constituent load

The study results include concentrations of Rare Earth Elements and stable isotope compositions of water from an acid mine drainage-affected watershed in southwest Colorado, the Upper Animas River watershed. This dataset is not publicly accessible because: The data will be released by another Federal Agency, USGS. It can be accessed through the following means: The data has been released to the U.S. Geological Survey's ScienceBase Catalog and may be accessed by the following link: https://doi.org/10.5066/P9OOHY1Q. Format: The data will be released through the U.S. Geological Survey's ScienceBase Catalog [https://www.sciencebase.gov/catalog/] The primary USGS author, Conor Newman, is developing the data release using the USGS procedures for documenting scientific data. This dataset is associated with the following publication: Newman, C., R. Cowie, R. Wilkin, and A. Navarre-Sitchler. Tracing metal sources and groundwater flow paths in the Upper Animas River watershed using rare earth elements and stable isotopes. Geochemistry: Exploration, Environment, Analysis. Geological Society of London, London, UK, 25(1): 2024-23, (2025).

Acid mine drainage (AMD) can cause ecological harm throughout the state of Colorado, including in the Upper Animas River watershed near Silverton. In the Upper Animas River watershed, a technique that includes the emplacement of hydraulic bulkheads within draining mines has been used to remediate AMD. Data for major ions and trace metal concentrations, isotopic compositions, and discharge from streams, draining mines, and springs were compiled for a period of approximately 30 years to better understand the processes occurring during the impoundment of water within underground mine workings and to define spatial extent of groundwater connectivity. These datasets were evaluated using statistical and geochemical modeling approaches.

These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.), major anions (chloride, nitrite+nitrate as nitrogen, sulfate, etc.), dissolved organic carbon, and general water quality characteristics in Canyon Mine containment pond water, sediment, vegetaiton and invertebrate samples collected in calendar year 2019.

These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.), major anions (chloride, nitrite+nitrate as nitrogen, sulfate, etc.), dissolved organic carbon, and general water quality characteristics in Canyon Mine containment pond water, sediment, vegetaiton and invertebrate samples collected in calendar year 2019.

Sediment samples were collected from Los Padres reservoir in the Carmel River watershed, central California coast, between July 11 and 17, 2017, using a CME-45 barge-mounted drill rig, to characterize sedimentary properties in the reservoir deposits following the Soberanes Fire of 2016 and high river flows in winter 2017. Borehole samples were recovered using direct push coring with an Osterberg piston sampler operated by Taber Drilling Company of Sacramento, California, and overseen by AECOM, Inc. Sediment was recovered using a split-barrel sampler and a rotary drill bit was added to the sampler where needed to penetrate coarse sediment. Samples from three boreholes are described in this data release: two sampled at multiple sediment depths (B2 and B7) and a third (B4) from which only the topmost sample is included. Each borehole was drilled to the depth of apparent pre-dam alluvium or bedrock. Alternate sections were described and sampled; every second section was discarded without examination. Geochemical data are reported for sediment cores. Data include short-lived cosmogenic and natural radionuclide activities for Lead-210; Radium-226, Cesium-137, Thorium-234, and excess Lead-210. The USGS gratefully acknowledges collaboration with B. Kozlowicz of AECOM, Inc., in the collection of these data. Purpose: Laboratory measurements of natural lead, radium, cesium, and thorium isotope concentrations in Los Padres reservoir, Carmel River watershed, California, to characterize post-fire sedimentation history.

The San Juan basin is a significant physical and structural element in the southeastern part of the Colorado Plateau physiographic province. The San Juan basin is in New Mexico, Colorado, Arizona, and Utah and has an area of about 21,600 square miles. The basin is about 140 miles wide and about 200 miles long. In the 1980’s and 1990’s, the San Juan basin was the focus of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) study. Investigation of the San Juan structural basin began in October 1984 with an objective, among others, to define and evaluate the aquifer system. As part of this analysis, a multi-publication series of reports were produced as Hydrologic Atlas 720 (HA-720) that described on 1:1,000,000-scale maps the subsurface configuration and hydrogeology of the San Jose, Nacimiento, and Animas Formations (Levings and others, 1990; HA-720-A), the Ojo Alamo Sandstone (Thorn and others, 1990; HA-720-B), the Kirtland Shale and Fruitland Formation (Kernodle and others, 1990; HA-720-C), the Pictured Cliffs Sandstone (Dam and others, 1990; HA-720-D), the Cliff House Sandstone (Thorn and others, 1990; HA-720-E), the Menefee Formation (Levings and others, 1990; HA-720-F), the Point Lookout Sandstone (Craigg and others, 1990; HA-720-G), the Gallup Sandstone (Kernodle and others, 1990; HA-720-H), the Dakota Sandstone (Craigg and others, 1990; HA-720-I), and the Morrison Formation (Dam and others, 1990; HA-720-J). This digital dataset contains spatial datasets corresponding to the contoured subsurface maps produced by the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) San Juan basin study. The data define the elevation, thickness, and extent of principal stratigraphic units of the basin. The digital data describe the following stratigraphic units: the San Jose Formation, the Ojo Alamo Sandstone, the Kirtland Shale and Fruitland Formation, the Pictured Cliffs Sandstone, the Cliff House Sandstone, the Menefee Formation, the Point Lookout Sandstone, the Gallup Sandstone, the Dakota Sandstone, and the Morrison Formation. Digital data for each unit are contained in individual features classes within a geodatabase (also saved as individual shapefiles). Feature classes have a single attribute, either elevation or thickness, that represents the contoured value. Contoured values are given in feet, to maintain consistency with the original publication, and in meters.

The USGS team measured base cations, aluminum (Al), iron (Fe), manganese (Mn), rare earth elements (REEs), dissolved organic carbon (DOC), major anions, and phosphorus (P) in eight streamwater grab (manual) samples during each of three high-flow events (E-1, E-2, E-3) at the forested headwater catchment W-9, Sleepers River, Vermont, USA. E-1 was a large fall rainstorm, E-2 was a multi-day snowmelt, and E-3 was a small late-summer storm. The eight samples from each event were speciated for total (unfiltered-acidified) and dissolved (0.45 µm filtered-acidified) fractions.