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.

Replicate water-quality samples are collected and prepared in the field and analyzed in the laboratory in identical ways so that they are considered to be the same in composition and analysis (Mueller and others, 2015). This data set includes one table of duplicate National Water-Quality Assessment Project (NAWQA) surface water and groundwater samples collected between October 1, 2012 and September 30, 2015 and analyzed by the USGS National Water Quality Laboratory (NWQL) using direct aqueous-injection liquid chromatography-tandem mass spectrometry (Schedule 2437; Sandstrom and others, 2015) for the determination of 225 pesticides at 288 sites. Mueller, D.K., Schertz, T.L., Martin, J.D., and Sandstrom, M.W., 2015, Design, analysis, and interpretation of field quality-control data for water-sampling projects: U.S. Geological Survey Techniques and Methods, book 4, chap. C4, 54 p., https://dx.doi.org/10.3133/tm4C4 Sandstrom, M.W., Kanagy, L.K., Anderson, C.A., Kanagy, C.J., 2015, Determination of pesticides and pesticide degradates in filtered water by direct aqueous-injection liquid chromatography-tandem mass spectrometry: U.S. Geological Survey Techniques and Methods, book 5, chap. B11, 54 p., https://dx.doi.org/10.3133/tm5B11

Replicate water-quality samples are collected and prepared in the field and analyzed in the laboratory in identical ways so that they are considered to be the same in composition and analysis (Mueller and others, 2015). This data set includes one table of duplicate National Water-Quality Assessment Project (NAWQA) surface water and groundwater samples collected between October 1, 2012 and September 30, 2015 and analyzed by the USGS National Water Quality Laboratory (NWQL) using direct aqueous-injection liquid chromatography-tandem mass spectrometry (Schedule 2437; Sandstrom and others, 2015) for the determination of 225 pesticides at 288 sites. Mueller, D.K., Schertz, T.L., Martin, J.D., and Sandstrom, M.W., 2015, Design, analysis, and interpretation of field quality-control data for water-sampling projects: U.S. Geological Survey Techniques and Methods, book 4, chap. C4, 54 p., https://dx.doi.org/10.3133/tm4C4 Sandstrom, M.W., Kanagy, L.K., Anderson, C.A., Kanagy, C.J., 2015, Determination of pesticides and pesticide degradates in filtered water by direct aqueous-injection liquid chromatography-tandem mass spectrometry: U.S. Geological Survey Techniques and Methods, book 5, chap. B11, 54 p., https://dx.doi.org/10.3133/tm5B11

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.

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 National Water Quality Network (NWQN) for Rivers and Streams includes 113 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program, National Water-Quality Assessment (NAWQA) Project. The NWQN includes 19 large river coastal sites, 44 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 113 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Water Program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release provides streamflow, nutrient, pesticide and sediment data collected and analyzed by NWQN and other historical water-quality networks from 1980-2015. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home.

The National Water Quality Network (NWQN) for Rivers and Streams includes 113 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program, National Water-Quality Assessment (NAWQA) Project. The NWQN includes 19 large river coastal sites, 44 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 113 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Water Program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release provides streamflow, nutrient, pesticide and sediment data collected and analyzed by NWQN and other historical water-quality networks from 1980-2015. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home.

The National Water Quality Network (NWQN) for Rivers and Streams includes 113 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program, National Water-Quality Assessment (NAWQA) Project. The NWQN includes 19 large river coastal sites, 44 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 113 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Water Program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release provides streamflow, nutrient, pesticide and sediment data collected and analyzed by NWQN and other historical water-quality networks from 1963-2016. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home.

The National Water Quality Network (NWQN) for Rivers and Streams includes 111 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program, National Water-Quality Assessment (NAWQA) Project. The NWQN includes 20 large river coastal sites, 41 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 111 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Water Program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release provides streamflow, nutrient, pesticide and sediment data collected and analyzed by NWQN and other historical water-quality networks from 1963-2017. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home.

The National Water Quality Network (NWQN) for Rivers and Streams includes 113 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program, National Water-Quality Assessment (NAWQA) Project. The NWQN includes 19 large river coastal sites, 44 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 113 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Water Program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release provides streamflow, nutrient, pesticide and sediment data collected and analyzed by NWQN and other historical water-quality networks from 1963-2016. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home.