The groundwater, surface water, and lake water-quality data were compiled from Water Quality Portal (https://www.waterqualitydata.us/) (National Water Quality Monitoring Council, 2015), USGS’s NAWQA Project’s data compilation (Oelsner and others, 2017), and the Montana Bureau of Mines and Geology (Montana Bureau of Mines, 2021), The compilation contains data for chloride, pH, specific conductance, sulfate, total dissolved solids (TDS) collected between water year 1970 to 2014. In addition 10 metals (aluminum, arsenic, barium, chromium, copper, iron, lead, selenium strontium, and zinc) analyzed during water years 1993 through 2014.

The surface water water-quality data were compiled from Water Quality Portal (https://www.waterqualitydata.us/) (National Water Quality Monitoring Council, 2015), USGS’s NAWQA Project’s data compilation (Oelsner and others, 2017) or the Montana Bureau of Mines and Geology (Montana Bureau of Mines, 2021), The compilation contains data for chloride, pH, specific conductance, sulfate, total dissolved solids (TDS) collected between water year 1970 to 2014. In addition 10 metals (aluminum, arsenic, barium, chromium, copper, iron, lead, selenium strontium, and zinc) analyzed during water years 1993 through 2014.

The surface water water-quality data were compiled from Water Quality Portal (https://www.waterqualitydata.us/) (National Water Quality Monitoring Council, 2015), USGS’s NAWQA Project’s data compilation (Oelsner and others, 2017) or the Montana Bureau of Mines and Geology (Montana Bureau of Mines, 2021), The compilation contains data for chloride, pH, specific conductance, sulfate, total dissolved solids (TDS) collected between water year 1970 to 2014. In addition 10 metals (aluminum, arsenic, barium, chromium, copper, iron, lead, selenium strontium, and zinc) analyzed during water years 1993 through 2014.

The surface water water-quality data were compiled from Water Quality Portal (https://www.waterqualitydata.us/) (National Water Quality Monitoring Council, 2015), USGS’s NAWQA Project’s data compilation (Oelsner and others, 2017) and the Montana Bureau of Mines and Geology (Montana Bureau of Mines, 2021), The compilation contains data for chloride, pH, specific conductance, sulfate, total dissolved solids (TDS) collected between water year 1970 to 2014. In addition 10 metals (aluminum, arsenic, barium, chromium, copper, iron, lead, selenium strontium, and zinc) analyzed during water years 1993 through 2014.

The surface water water-quality data were compiled from Water Quality Portal (https://www.waterqualitydata.us/) (National Water Quality Monitoring Council, 2015), USGS’s NAWQA Project’s data compilation (Oelsner and others, 2017) and the Montana Bureau of Mines and Geology (Montana Bureau of Mines, 2021), The compilation contains data for chloride, pH, specific conductance, sulfate, total dissolved solids (TDS) collected between water year 1970 to 2014. In addition 10 metals (aluminum, arsenic, barium, chromium, copper, iron, lead, selenium strontium, and zinc) analyzed during water years 1993 through 2014.

A comprehensive study to evaluate water-quality trends in the International Souris River Basin, Saskatchewan and Manitoba, Canada and North Dakota, United States was completed by the U.S. Geological Survey (USGS) in cooperation with the International Joint Commission and International Souris River Board. This page contains water-quality data for stream and reservoir sites in the Souris River Basin in North Dakota, Saskatchewan, and Manitoba. Each file contains information on major ions (MI), nutrients (NUT), trace metals (TM), sediment (SED), and dissolved oxygen (PHY). These data contain numerous columns that are described in the entity and attributes of these files. These files contain the water-quality observations for the statistical summary tables in the report cited in this data release (Nustad and Tatge, 2023).The siteinfo.table.csv file can be used to cross reference the sites with the main report (Nustad and Tatge, 2023).

A comprehensive study to evaluate water-quality trends in the International Souris River Basin, Saskatchewan and Manitoba, Canada and North Dakota, United States was completed by the U.S. Geological Survey (USGS) in cooperation with the International Joint Commission and International Souris River Board. This page contains water-quality data for stream and reservoir sites in the Souris River Basin in North Dakota, Saskatchewan, and Manitoba. Each file contains information on major ions (MI), nutrients (NUT), trace metals (TM), sediment (SED), and dissolved oxygen (PHY). These data contain numerous columns that are described in the entity and attributes of these files. These files contain the water-quality observations for the statistical summary tables in the report cited in this data release (Nustad and Tatge, 2023).The siteinfo.table.csv file can be used to cross reference the sites with the main report (Nustad and Tatge, 2023).

A comprehensive study to evaluate water-quality trends in the International Souris River Basin, Saskatchewan and Manitoba, Canada and North Dakota, United States was completed by the U.S. Geological Survey (USGS) in cooperation with the International Joint Commission and International Souris River Board. This page contains water-quality data for stream and reservoir sites in the Souris River Basin in North Dakota, Saskatchewan, and Manitoba. Each file contains information on major ions (MI), nutrients (NUT), trace metals (TM), sediment (SED), and dissolved oxygen (PHY). These data contain numerous columns that are described in the entity and attributes of these files. These files contain the water-quality observations for the statistical summary tables in the report cited in this data release (Nustad and Tatge, 2023).The siteinfo.table.csv file can be used to cross reference the sites with the main report (Nustad and Tatge, 2023).

This U.S. Geological Survey (USGS) data release contains stream water chemistry and streamflow data collected in late August and early September, 2021 from 28 sites located throughout Colorado, USA. The sampled streams all drain high-elevation mountain watersheds in areas where the bedrock is hydrothermally altered and contains abundant sulfide minerals. Most sampled streams are therefore affected by natural acid-rock drainage. All sites had been sampled in prior years so that the 2021 data could be used to evaluate potential changes in stream water chemistry in recent decades. Streamflow was also quantified at most sites using data from a sodium chloride slug addition wherein specific conductivity readings were used as a surrogate for the tracer concentration.

This U.S. Geological Survey (USGS) data release contains stream water chemistry and streamflow data collected in late August and early September, 2021 from 28 sites located throughout Colorado, USA. The sampled streams all drain high-elevation mountain watersheds in areas where the bedrock is hydrothermally altered and contains abundant sulfide minerals. Most sampled streams are therefore affected by natural acid-rock drainage. All sites had been sampled in prior years so that the 2021 data could be used to evaluate potential changes in stream water chemistry in recent decades. Streamflow was also quantified at most sites using data from a sodium chloride slug addition wherein specific conductivity readings were used as a surrogate for the tracer concentration.