These data represent the acid neutralization potential and grain size analysis of 13 samples, 2 duplicate samples, of modern and legacy iron and steel slag from the Chicago-Gary area of Illinois and Indiana, USA.

These data represent the major, minor, and trace element compositions of modern and legacy iron and steel slag from the Chicago-Gary area of Illinois and Indiana, USA.

These data represent the major, minor, and trace element compositions of laboratory generated leachates of modern and legacy iron and steel slag from the Chicago-Gary area of Illinois and Indiana, USA using USEPA method 1312 Synthetic Precipitation Leaching Procedure.

These data represent the phosphate removal capacity of modern and legacy iron and steel slag from the Chicago-Gary area of Illinois and Indiana, USA, based on batch leaching experiments. Also included are major, minor, and trace element compositions of the leachates along with associated water parameters pH, specific conductivity, and alkalinity. Details of the batch experiments may be reviewed in the journal article listed in the cross-reference section of this data release titled, "Geochemical Characterization of Iron and Steel Slag and Its Potential to Remove Phosphate and Neutralize Acid".

These data represent the major, minor, and trace element compositions of effluent water samples generated by column experiments of modern and legacy iron and steel slag from the Chicago-Gary area of Illinois and Indiana. Details of the column experiments may be reviewed in the journal article listed in the cross-reference section of this data release titled, "Geochemical Characterization of Iron and Steel Slag and Its Potential to Remove Phosphate and Neutralize Acid".

Grain size analysis using an Advantech Sonic Sifter Separator was conducted as part of a study examining the occurrence of chromium and natural and anthropogenic hexavalent Chromium, Cr(VI) in groundwater. Data will be used to estimate naturally-occurring background Cr(VI) concentrations upgradient, near the plume margins, and downgradient from a mapped Cr(VI) contamination plume near Hinkley, CA (Izbicki and Groover, 2016). Following field collection the samples were sieved into the greater than and less than 2 millimeter size fractions. The less than 2 millimeter fraction was sifted into seven grain size ranges. Each size fraction was weighed to 0.1 grams and photo documented. The cooperator for this study is the Lahontan Regional Water Quality Control Board.

During water years 2016–2020, the U.S. Geological Survey, in cooperation with the Illinois Environmental Protection Agency, operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, suspended sediment, and phosphorus concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling data and surrogate regression (imputation). The data release comprises a single csv file containing daily timeseries of conentration and uncertainty for each monitoring station.

During water years 2016–2022 (a water year begins on October 1 and ends on September 30), the U.S. Geological Survey (USGS), in cooperation with the Illinois Environmental Protection Agency (Illinois EPA), operated continuous monitoring stations on eight of the major rivers in Illinois to better quantify nutrient and sediment loadings from the State of Illinois to the Mississippi River. This data release presents estimates of daily nitrate, phosphorus, and suspended sediment concentrations and uncertainty over that period. The concentration estimates are based on a combination of discrete sampling and surrogate regression (imputation); see Hodson and others (2021) for details on the imputation model. The data release comprises a single comma-separated values (csv) file containing daily timeseries of concentration and uncertainty for each monitoring station. Reference cited: Hodson, T.O., Terrio, P.J., Peake, C.S., and Fazio, D.J., 2021, Continuous Monitoring and Bayesian Estimation of Nutrient and Sediment Loads from Illinois Watersheds, for water years 2016–2020: U.S. Geological Survey Scientific Investigations Report 2021-5092. [Also available at https://doi.org/10.3133/sir20215092].

During the 2018–20 water years, the U.S. Geological Survey, in cooperation with the Metropolitan Water Reclamation District of Greater Chicago, operated a continuous monitoring station on the Des Plaines River at Route 53 at Joliet, Illinois (USGS station 05537980), to better quantify nutrient and sediment loadings from the Greater Chicago Area to the Illinois River. This data release presents estimates of daily nitrate, suspended sediment, and phosphorus concentrations and uncertainty from that period. The concentration estimates are based on a combination of discrete sampling, continuously monitored surrogates, and surrogate regression (Bayesian imputation). The data release comprises a single csv file containing daily timeseries of streamflow, concentration, and uncertainty.

This data release is part of a study examining the occurrence of chromium and natural and anthropogenic hexavalent Chromium, Cr(VI) in groundwater. Data will be used to estimate naturally-occurring background Cr(VI) concentrations upgradient, near the plume margins, and downgradient from a mapped Cr(VI) contamination plume near Hinkley, CA (Izbicki and Groover, 2016). The data release includes grain size distribution, photographic, and associated chemical and mineral analysis data for 36 sediment core and alluvium samples as well as Scanning Electron Microscopy analysis on select grains from magnetic and heavy mineral separates collected near Hinkley, CA. The cooperator for this study is the Lahontan Regional Water Quality Control Board. Results are provided in this data release organized by analysis type.