Water quality replicate sample data and field blank data was collected at the Colorado River above Imperial Dam, Colorado River below Cooper Wasteway, Yuma Main Drain, and 242 Lateral during 2017 and 2018. Instantaneous discharge data was collected at the Cooper Wasteway, Yuma Main Drain, and 242 Lateral from January 2017 to March 2019. Instantaneous discharge readings were recorded at a fixed interval of 5 minutes. Mean daily discharge data was collected at the Colorado River above Imperial Dam, Cooper Wasteway, Yuma Main Drain, and 242 Lateral from January 2017 to March 2019. Instantaneous discharge and mean daily discharge data was provided to the USGS by the International Boundary and Water Commission (IBWC). Discrete water-quality samples were collected at the Colorado River above Imperial Dam, Colorado River below Cooper Wasteway, Yuma Main Drain, and 242 Lateral during 2017, 2018, through March 2019 and values were used to compute dissolved solids concentrations using BOR's method.

The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) comprises 117 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. This dataset includes field quality-control results (field blank and field replicate concentrations), along with the water-quality result of each associated surface-water sample, of water samples collected from October 2012 through September 2017 at NWQN sites. This dataset includes 2 tables and 6 files of plots of the data. Tables are in Comma Separated Value, CSV, format and plotfiles are in Portable Document Format, PDF, format. The plotfiles are intended to provide a succinct view of the data. Table1.NWQNFieldBlanksC3.csv Table2.NWQNFieldReplicatesC3.csv PlotFile 1. Time-series plots showing concentrations of nutrients, carbon, UV absorbance, and suspended sediments in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 2. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for nutrients, carbon, and suspended sediment in samples in the National Water Quality Network, water years 2013–17 . PlotFile 3. Time-series plots showing concentrations of major ions and trace elements in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 4. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for major ions and trace elements in the National Water Quality Network, water years 2013–17. PlotFile 5. Time-series plots showing concentrations of pesticides in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 6. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for pesticides in the National Water Quality Network, water years 2013–17.

The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) comprises 117 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. This dataset includes field quality-control results (field blank and field replicate concentrations), along with the water-quality result of each associated surface-water sample, of water samples collected from October 2012 through September 2017 at NWQN sites. This dataset includes 2 tables and 6 files of plots of the data. Tables are in Comma Separated Value, CSV, format and plotfiles are in Portable Document Format, PDF, format. The plotfiles are intended to provide a succinct view of the data. Table1.NWQNFieldBlanksC3.csv Table2.NWQNFieldReplicatesC3.csv PlotFile 1. Time-series plots showing concentrations of nutrients, carbon, UV absorbance, and suspended sediments in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 2. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for nutrients, carbon, and suspended sediment in samples in the National Water Quality Network, water years 2013–17 . PlotFile 3. Time-series plots showing concentrations of major ions and trace elements in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 4. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for major ions and trace elements in the National Water Quality Network, water years 2013–17. PlotFile 5. Time-series plots showing concentrations of pesticides in surface-water samples and field blanks in the National Water Quality Network, water years 2013–17. PlotFile 6. Scatterplots showing concentrations of pairs of surface-water samples and field replicates for pesticides in the National Water Quality Network, water years 2013–17.

In 2015-2016, physicochemical properties and chemical characteristics of stream water, bed sediment, groundwater, and soil were determined in watersheds located outside of, but in proximity to, the Peason Ridge Training Area and Main Post at the Joint Readiness Training Center and Fort Polk boundaries to document background trace element concentrations. Water samples were analyzed for physicochemical properties, major inorganic ions, selected trace elements, and dissolved organic carbon. Selected trace elements included antimony, arsenic, cadmium, copper, iron, lead, manganese, mercury, and zinc. Stream bed-sediment and soil samples were analyzed for major inorganic ions, selected trace elements, and grain size distribution. Surface-water samples were collected near the downstream transect of each stream reach. Monitoring wells were located adjacent to the stream reach and in close proximity to the surface-water sampling sites. Bulk bed-sediment samples were collected during normal low-flow conditions. Each sample consisted of a composite sample from five locations (right edge, left edge, and center of a middle transect, then upstream and downstream of the middle transect) within each stream reach. Three soil samples, one from hilltops, one from side slopes, and one from riparian zones, were collected from areas adjacent to each stream reach. Each soil sample consisted of 5 to 10 grab samples collected by a 21-inch-long, 5/8-inch internal diameter stainless-steel hand auger and composited in Teflon lined pans. All samples were collected following USGS sampling protocols. This data release provides database and mapping information for assessment of trace element concentrations in stream water, bed sediment, groundwater, and soil found in relatively pristine and undisturbed watersheds in proximity to watersheds used for military training.

In 2015-2016, physicochemical properties and chemical characteristics of stream water, bed sediment, groundwater, and soil were determined in watersheds located outside of, but in proximity to, the Peason Ridge Training Area and Main Post at the Joint Readiness Training Center and Fort Polk boundaries to document background trace element concentrations. Water samples were analyzed for physicochemical properties, major inorganic ions, selected trace elements, and dissolved organic carbon. Selected trace elements included antimony, arsenic, cadmium, copper, iron, lead, manganese, mercury, and zinc. Stream bed-sediment and soil samples were analyzed for major inorganic ions, selected trace elements, and grain size distribution. Surface-water samples were collected near the downstream transect of each stream reach. Monitoring wells were located adjacent to the stream reach and in close proximity to the surface-water sampling sites. Bulk bed-sediment samples were collected during normal low-flow conditions. Each sample consisted of a composite sample from five locations (right edge, left edge, and center of a middle transect, then upstream and downstream of the middle transect) within each stream reach. Three soil samples, one from hilltops, one from side slopes, and one from riparian zones, were collected from areas adjacent to each stream reach. Each soil sample consisted of 5 to 10 grab samples collected by a 21-inch-long, 5/8-inch internal diameter stainless-steel hand auger and composited in Teflon lined pans. All samples were collected following USGS sampling protocols. This data release provides database and mapping information for assessment of trace element concentrations in stream water, bed sediment, groundwater, and soil found in relatively pristine and undisturbed watersheds in proximity to watersheds used for military training.

This dataset contains data collected from field blanks. Field blanks are deionized water processed in the field by community technicians using processing methods identical to those for surface water samples. Field blanks are then analyzed in the laboratory following procedures identical to those for surface water samples.

This dataset contains data collected from field blanks. Field blanks are deionized water processed in the field by community technicians using processing methods identical to those for surface water samples. Field blanks are then analyzed in the laboratory following procedures identical to those for surface water samples.

In 2021–23, the U.S. Geological Survey (USGS), in cooperation with the Ohio Division of Natural Resources, led a study to characterize baseline water quality (2021–23) in eastern Ohio, as they relate to hydraulic fracturing and (or) other oil and gas extraction-related activities. Water-quality data were collected eight times at each of eight sampling sites during a variety of flow conditions to assess baseline water quality. Quality-control (QC) samples collected before and during sampling consisted of blanks and replicates. Blank samples were used to check for contamination potentially introduced during sample collection, processing, equipment cleaning, or analysis. Replicate samples were used to determine the reproducibility or variability in the collection and analysis of environmental samples. All QC samples were collected and processed according to protocols described in the “National Field Manual for the Collection of Water-Quality Data” (USGS, variously dated). To ensure sample integrity and final quality of data, QC samples (one equipment blank, three field blanks, and five replicate samples) were collected for major ions, nutrients, and organics. This data set includes one table of blank samples and one table of field replicate samples. U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A10, available online at http://pubs.water.usgs.gov/twri9A.

In 2021–23, the U.S. Geological Survey (USGS), in cooperation with the Ohio Division of Natural Resources, led a study to characterize baseline water quality (2021–23) in eastern Ohio, as they relate to hydraulic fracturing and (or) other oil and gas extraction-related activities. Water-quality data were collected eight times at each of eight sampling sites during a variety of flow conditions to assess baseline water quality. Quality-control (QC) samples collected before and during sampling consisted of blanks and replicates. Blank samples were used to check for contamination potentially introduced during sample collection, processing, equipment cleaning, or analysis. Replicate samples were used to determine the reproducibility or variability in the collection and analysis of environmental samples. All QC samples were collected and processed according to protocols described in the “National Field Manual for the Collection of Water-Quality Data” (USGS, variously dated). To ensure sample integrity and final quality of data, QC samples (one equipment blank, three field blanks, and five replicate samples) were collected for major ions, nutrients, and organics. This data set includes one table of blank samples and one table of field replicate samples. U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A10, available online at http://pubs.water.usgs.gov/twri9A.

This data release contains six different datasets that were used in the report SIR 2018-5108. These datasets contain discharge data, discrete dissolved-solids data, quality-control discrete dissolved data, and computed mean dissolved solids data that were collected at various locations between the Hoover Dam and the Imperial Dam. Study Sites: Site 1: Colorado River below Hoover Dam Site 2: Bill Williams River near Parker Site 3: Colorado River below Parker Dam Site 4: CRIR Main Canal Site 5: Palo Verde Canal Site 6: Colorado River at Palo Verde Dam Site 7: CRIR Lower Main Drain Site 8: CRIR Upper Levee Drain Site 9: PVID Outfall Drain Site 10: Colorado River above Imperial Dam Discrete Dissolved-solids Dataset and Replicate Samples for Discrete Dissolved-solids Dataset: The Bureau of Reclamation collected discrete water-quality samples for the parameter of dissolved-solids (sum of constituents). Dissolved-solids, measured in milligrams per liter, are the sum of the following constituents: bicarbonate, calcium, carbonate, chloride, fluoride, magnesium, nitrate, potassium, silicon dioxide, sodium, and sulfate. These samples were collected on a monthly to bimonthly basis at various time periods between 1990 and 2016 at Sites 1-5 and Sites 7-10. No data were collected for Site 6: Colorado River at Palo Verde Dam. The Bureau of Reclamation and the USGS collected discrete quality-control replicate samples for the parameter of dissolved-solids, sum of constituents measured in milligrams per liter. The USGS collected discrete quality-control replicate samples in 2002 and 2003 and the Bureau of Reclamation collected discrete quality-control replicate samples in 2016 and 2017. Listed below are the sites where these samples were collected at and which agency collected the samples. Site 3: Colorado River below Parker Dam: USGS and Reclamation Site 4: CRIR Main Canal: Reclamation Site 5: Palo Verde Canal: Reclamation Site 7: CRIR Lower Main Drain: Reclamation Site 8: CRIR Upper Levee Drain: Reclamation Site 9: PVID Outfall Drain: Reclamation Site 10: Colorado River above Imperial Dam: USGS and Reclamation Monthly Mean Datasets and Mean Monthly Datasets: Monthly mean discharge data (cfs), flow weighted monthly mean dissolved-solids concentrations (mg/L) data and monthly mean dissolved-solids load data from 1990 to 2016 were computed using raw data from the USGS and the Bureau of Reclamation. This data were computed for all 10 sites. Flow weighted monthly mean dissolved-solids concentration and monthly mean dissolved-solids load were not computed for Site 2: Bill Williams River near Parker. The monthly mean datasets that were calculated for each month for the period between 1990 and 2016 were used to compute the mean monthly discharge and the mean monthly dissolved-solids load for each of the 12 months within a year. Each monthly mean was weighted by how many days were in the month and then averaged for each of the twelve months. This was computed for all 10 sites except mean monthly dissolved-solids load were not computed at Site 2: Bill Williams River near Parker. Site 8a: Colorado River between Parker and Palo Verde Valleys was computed by summing the data from sites 6, 7 and 8. Bill Williams Daily Mean Discharge, Instantaneous Dissolved-solids Concentration, and Daily Means Dissolved-solids Load Dataset: Daily mean discharge (cfs), instantaneous solids concentration (mg/L), and daily mean dissolved solids load were calculated using raw data collected by the USGS and the Bureau of Reclamation. This data were calculated for Site 2: Bill Williams River near Parker for the period of January 1990 to February 2016. Palo Verde Irrigation District Outfall Drain Mean Daily Discharge Dataset: The Bureau of Reclamation collected mean daily discharge data for the period of 01/01/2005 to 09/30/2016 at the Palo Verde Irrigation District (PVID) outfall drain using a stage-discharge relationship.