The data herein were collected in support of a larger study in Gwinnett County, Georgia, on the potential impacts of on-site waste water treatment (septic systems) on Lake Lanier water quality. Until recently, a missing component in this assessment was the inclusion of historical sediment and associated nutrient accumulation data from the lake to place results in a broader context. To this end, the USGS collected sediment cores from ten locations that varied in water depth as well as proximity to residential areas with septic systems. Samples were collected using either a gravity corer or box corer depending on site conditions. Cores were sub-sampled and processed for laboratory analyses. Laboratory analyses were conducted to evaluate nutrient concentrations (carbon, nitrogen, and phosphorus) in sediments, stable isotope ratios of carbon and nitrogen in the sediment organic matter, cesium-137 for select samples, and trace and heavy metals. The latter constituents (cesium-137 and trace and heavy metals) were used primarily to help constrain mass accumulations rates (MAR) and assign ages to each sub-sample so that temporal changes in nutrient concentrations could be evaluated in concert with timing of shoreline development. Version 2.0 adds three new data files: 1) information linking specific replicate sediment cores to specific laboratory analyses, 2) activities of five radioisotopes (cesium-137, lead-210, radium-226, thorium-234, and potassium-40), and 3) the concentration of biogenic silica of sediment samples from all 10 coring sites. This revision also corrects a shift in the latitude and longitude of the coring sites.

The data herein were collected in support of a larger study in Gwinnett County, Georgia, on the potential impacts of on-site waste water treatment (septic systems) on Lake Lanier water quality. Until recently, a missing component in this assessment was the inclusion of historical sediment and associated nutrient accumulation data from the lake to place results in a broader context. To this end, the USGS collected sediment cores from ten locations that varied in water depth as well as proximity to residential areas with septic systems. Samples were collected using either a gravity corer or box corer depending on site conditions. Cores were sub-sampled and processed for laboratory analyses. Laboratory analyses were conducted to evaluate nutrient concentrations (carbon, nitrogen, and phosphorus) in sediments, stable isotope ratios of carbon and nitrogen in the sediment organic matter, cesium-137 for select samples, and trace and heavy metals. The latter constituents (cesium-137 and trace and heavy metals) were used primarily to help constrain mass accumulations rates (MAR) and assign ages to each sub-sample so that temporal changes in nutrient concentrations could be evaluated in concert with timing of shoreline development. Version 2.0 adds three new data files: 1) information linking specific replicate sediment cores to specific laboratory analyses, 2) activities of five radioisotopes (cesium-137, lead-210, radium-226, thorium-234, and potassium-40), and 3) the concentration of biogenic silica of sediment samples from all 10 coring sites. This revision also corrects a shift in the latitude and longitude of the coring sites.

This data release contains model inputs, outputs, and source code (written in R) for the calculation of daily total phosphorus (TP) concentrations at a sampling site operated by the Klamath Tribes (WR6000), which is located 5 miles downstream of USGS streamgage 11502500, Williamson River below Sprague River near Chiloquin, Oregon. Daily streamflow data from 11502500 were used to calibrate the model along with data provided for the Klamath Tribes for site WR6000. Daily TP concentrations were calculated from 1991-2019 using the USGS Weighted Regression on Time, Discharge, and Season (WRTDS) model. Calibration data are bi-weekly (every two weeks) TP concentrations collected at site WR6000 and analyzed by the Klamath Tribes at the Sprague River Water Quality Laboratory (SRWQL). All concentrations are reported in milligrams per liter (mg/L).

This data release contains model inputs, outputs, and source code (written in R) for the calculation of daily total phosphorus (TP) concentrations at a sampling site operated by the Klamath Tribes (WR6000), which is located 5 miles downstream of USGS streamgage 11502500, Williamson River below Sprague River near Chiloquin, Oregon. Daily streamflow data from 11502500 were used to calibrate the model along with data provided for the Klamath Tribes for site WR6000. Daily TP concentrations were calculated from 1991-2019 using the USGS Weighted Regression on Time, Discharge, and Season (WRTDS) model. Calibration data are bi-weekly (every two weeks) TP concentrations collected at site WR6000 and analyzed by the Klamath Tribes at the Sprague River Water Quality Laboratory (SRWQL). All concentrations are reported in milligrams per liter (mg/L).

The Archive.zip data set contains R source code and inputs and selected outputs associated with regression analyses used to estimate total phosphorus loads for selected sites on Great Lakes tributaries for water years 2014–2018

The Archive.zip data set contains R source code and inputs and selected outputs associated with regression analyses used to estimate total phosphorus loads for selected sites on Great Lakes tributaries for water years 2014–2018

Concentrations and loads of total phosphorus, dissolved phosphorus, and suspended solids were estimated for three sites on the Lower Fox River for October 1988 through September 2021. The sites are the Fox River at Neenah-Menasha (040844105), Fox River at DePere (04085059), and Fox River at the Mouth (040851385). Data analysis was conducted with the Weighted Regressions on Time, Discharge, and Season (WRTDS) method. Daily loads were estimated using the WRTDS method with Kalman filtering. To determine changes in loads over this period, the annual load results were flow-normalized to standardize for the varying flow dynamics that occurred among years. The model archive contains the R code for running the WRTDS model, functions used by the R code, and the input data files. The output folder contains WRTDS model output summarized by 1) water year, 2) water year and season, and 3) water year, season, and three specified values of discharge. The models folder contains the WRTDS model objects. This dataset includes a separate file with all phosphorus, nitrogen, and suspended solids sample data for the three study sites from 1973 to 2022. This file includes a column indicating who collected the samples.

Concentrations and loads of total phosphorus, dissolved phosphorus, and suspended solids were estimated for three sites on the Lower Fox River for October 1988 through September 2021. The sites are the Fox River at Neenah-Menasha (040844105), Fox River at DePere (04085059), and Fox River at the Mouth (040851385). Data analysis was conducted with the Weighted Regressions on Time, Discharge, and Season (WRTDS) method. Daily loads were estimated using the WRTDS method with Kalman filtering. To determine changes in loads over this period, the annual load results were flow-normalized to standardize for the varying flow dynamics that occurred among years. The model archive contains the R code for running the WRTDS model, functions used by the R code, and the input data files. The output folder contains WRTDS model output summarized by 1) water year, 2) water year and season, and 3) water year, season, and three specified values of discharge. The models folder contains the WRTDS model objects. This dataset includes a separate file with all phosphorus, nitrogen, and suspended solids sample data for the three study sites from 1973 to 2022. This file includes a column indicating who collected the samples.

This data release comprises four datasets that represent Phosphorus concentration in the A and C horizon of soils within the conterminous United States. The source dataset is a slight modification of the data published in the report "Geochemical and mineralogical data for soils of the conterminous United States", http://pubs.usgs.gov/ds/801/. Data were interpolated for use in models associated with the National Water Quality Assessment program of the USGS. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using Inverse Distance Weight (IDW) algorithm. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using IDW, and then aggregated to Geologic Mapping Units (GMUs).

This data release comprises four datasets that represent Phosphorus concentration in the A and C horizon of soils within the conterminous United States. The source dataset is a slight modification of the data published in the report "Geochemical and mineralogical data for soils of the conterminous United States", http://pubs.usgs.gov/ds/801/. Data were interpolated for use in models associated with the National Water Quality Assessment program of the USGS. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using Inverse Distance Weight (IDW) algorithm. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using IDW, and then aggregated to Geologic Mapping Units (GMUs).