The dataset contains estimates for total phosphorus flux from wastewater treatment plants that discharge to surface water within the Red River of the North Basin in the United States and subbasins. Shapefiles defining the subbasins are available as part of the same data release in which these data are published. Estimates of wastewater treatment plant total phosphorus flux (or load) were calculated by Tammy Ivanhnenko for the years 1978, 1980, 1982, 1984, 1986, 1988, 1990, 1992, 1996, 2000, 2004, 2008, and 2012. Flux estimates were based on the average discharge from the wastewater treatment plants and treatment level, both reported as part of the U.S. Environmental Protection Agency's Clean Watershed Needs Survey, https://www.epa.gov/cwns. The treatment level concentrations used for total phosphorus are based on data from a 2000 U.S. Environmental Protection Agency report (table 2-17; Tetra Tech, Inc. and Andrew Stoddard & Associates, 2000). Tetra Tech, Inc. and Andrew Stoddard & Associates, 2000, Progress in water quality-An evaluation of the National investment in municipal wastewater treatment: U.S. Environmental Protection Agency Technical Report EPA-832-R-00-008, 452 p., accessed November 5, 2015, at http://water.epa.gov/polwaste/wastewater/treatment/benefits.cfm.

The dataset contains estimates of annual flow and annual flux in kilograms for six sites in the Red River of the North Basin (identified as basin 1, 2, 3, 4, 5, and 8). The shape files that are part of this data release document the basins and the streamgage locations are also provided in an associated shape file.

Phosphorus estimates, from fertilizer and manure, for the period 1970-2012 for eight subbasins (see accompanying shapefiles) of the Red River of the North Basin in kilograms per square kilometer.

Phosphorus estimates, from fertilizer and manure, for the period 1970-2012 for eight subbasins (see accompanying shapefiles) of the Red River of the North Basin in kilograms per square kilometer.

In this data release, we provide the data used to compute total annual phosphorus loads from tributaries and direct drainages to the Great Lakes during 2012-18 using the model load ratio approach and the unit area load approach and the resulting annual loads for 2012–18. This data release consists of: (1) measured loads at 24 sites, computed using the surrogate regression approach (Robertson et al., 2018; Koltun, 2020) that were monitored as part of the Great Lakes Restoration Initiative project, (2) estimated annual loads at point source facilities throughout the Great Lakes Basin obtained from the U.S. Environmental Protection Agency and state agencies, (3) loads subdivided into nonpoint and point source contributions, (4) extrapolation factors for each basin (nonpoint model load ratios, nonpoint yields, point source delivery factors), and (5) estimated annual loads for each tributary and direct drainage area to the Great Lakes during 2012–18. This data release consists of three tab delimited files: (1) ReferenceSite.txt, which contains all of the information (site data and phosphorus loads from SPARROW (Robertson and Saad, 2019) and measured during 2012–18 for the 24 reference (extrapolation sites) used in this study, (2) PointSource.txt, which contains all of the measured or extrapolated point source information for wastewater treatment plants in the Great Lake Basin for 2012–18; and (3) ExtrapolatedLoads.txt, which contains all of the nonpoint model load ratios, point source delivery ratios, measured wastewater treatment plant loads, and resulting annual loads for each tributary and direct drainage area in the Great Lakes Basin for the long-term average and 2012–18.

In this data release, we provide the data used to compute total annual phosphorus loads from tributaries and direct drainages to the Great Lakes during 2012-18 using the model load ratio approach and the unit area load approach and the resulting annual loads for 2012–18. This data release consists of: (1) measured loads at 24 sites, computed using the surrogate regression approach (Robertson et al., 2018; Koltun, 2020) that were monitored as part of the Great Lakes Restoration Initiative project, (2) estimated annual loads at point source facilities throughout the Great Lakes Basin obtained from the U.S. Environmental Protection Agency and state agencies, (3) loads subdivided into nonpoint and point source contributions, (4) extrapolation factors for each basin (nonpoint model load ratios, nonpoint yields, point source delivery factors), and (5) estimated annual loads for each tributary and direct drainage area to the Great Lakes during 2012–18. This data release consists of three tab delimited files: (1) ReferenceSite.txt, which contains all of the information (site data and phosphorus loads from SPARROW (Robertson and Saad, 2019) and measured during 2012–18 for the 24 reference (extrapolation sites) used in this study, (2) PointSource.txt, which contains all of the measured or extrapolated point source information for wastewater treatment plants in the Great Lake Basin for 2012–18; and (3) ExtrapolatedLoads.txt, which contains all of the nonpoint model load ratios, point source delivery ratios, measured wastewater treatment plant loads, and resulting annual loads for each tributary and direct drainage area in the Great Lakes Basin for the long-term average and 2012–18.

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.

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