Per- and polyfluoroalkyl substances (PFAS), major elements, and trace elements in surface waters of the Upper Colorado River Basin, May 2022 to June 2024

Per- and polyfluoroalkyl substances (PFAS) and co-occurring constituents were assessed in the Upper Colorado River Basin during three sampling campaigns conducted from 2022 to 2024. In May 2022, discrete water samples were collected at five sites along a longitudinal transect from the Fraser River near Tabernash, Colorado to the Colorado River near Grand Junction, Colorado. Time series water samples were collected at three U.S. Geological Survey stream gages (Colorado River near Cameo, CO, USGS-09095500; Colorado River near Colorado-Utah state line, USGS-09163500; Gunnison River near Grand Junction, Colorado, USGS-09152500) between June 2022 and April 2023. The third campaign consisted of three float trips (June 2023, October 2023, and May/June 2024) that collected water samples along a longitudinal profile from below Kremmling, Colorado to near Potash, Utah. Water samples were analyzed using a “toolbox” of chemical and physical analyses, including field parameters, PFAS, pharmaceuticals, major elements, trace elements, and optical properties (reported in a companion data release). This data release compiles the overall metadata as an .xml file, along with two tabular comma seperated files with detailed metadata one on site locations T01_Site_Info_UCOL.csv and a full list of constituents in T02_Constituents_UCOL.csv describing the attributes for the Observed_Property listed in T03_UCOL_Data.csv. The full set of chemical and physical data for all sampling sites and events along with the analytical method are provided as the file T03_UCOL_Data.csv.