Streambed sediment samples were collected in October 2016 from streams tributary to Wisconsin’s western Lake Michigan shoreline. Streams included two Areas of Concern (AOCs), two non-AOC comparisons, and two additional non-AOC study areas. Within the Milwaukee Estuary AOC, samples were collected from the Milwaukee River (three subsites), the Menomonee River (two subsites), the Kinnickinnic River (2 subsites), and the Milwaukee Harbor (one subsite). The Milwaukee, Menomonee, and Kinnickinnic Rivers converge in the Milwaukee Harbor and then discharge to Lake Michigan. Within the Sheboygan River AOC, samples were collected at three subsites. Samples were also collected at two subsites in the Manitowoc River and two subsites in the Root River, the two non-AOC comparison rivers. Two subsites in the Kewaunee River and two subsites in Oak Creek, the two additional non-AOC study areas, were also sampled.

This data release contains bioassay data from sediment toxicity tests conducted by the USGS Columbia Environmental Research Center (CERC) with 66 sediment samples collected from in and around the Upper Columbia River in the fall of 2013. Toxicity testing was conducted from fall 2013 through summer 2014 with the amphipod, Hyalella azteca, the midge Chironomus dilutus, and the mussel Lampsilis siliquoidea. Short-term toxicity endpoints (10-28 d) included survival, weight, and biomass of all test organisms. Long-term tests with amphipods (42 d) and midges (about 50 d) included reproduction endpoint. Sediments were analyzed for physical and chemical characteristics, including particle size distribution, total organic carbon, acid volatile sulfide, slag content, and concentrations of metals in total-recoverable and simultaneously-extracted fractions. Porewaters were separated by centrifugation and by peepers (diffusion samplers) and were analyzed for filterable metals, dissolved organic carbon, and major ions. These data are intended to be used to characterize concentration-response relationships between metals concentrations and toxicity endpoints and to estimate site-specific toxicity thresholds for select metals or metal mixtures. These thresholds will be used to evaluate risks or injuries to the benthic invertebrate community associated with exposure to contaminated sediments and to develop goals for remediation of sediments of the Upper Columbia River.

This data release contains bioassay data from sediment toxicity tests conducted by the USGS Columbia Environmental Research Center (CERC) with 66 sediment samples collected from in and around the Upper Columbia River in the fall of 2013. Toxicity testing was conducted from fall 2013 through summer 2014 with the amphipod, Hyalella azteca, the midge Chironomus dilutus, and the mussel Lampsilis siliquoidea. Short-term toxicity endpoints (10-28 d) included survival, weight, and biomass of all test organisms. Long-term tests with amphipods (42 d) and midges (about 50 d) included reproduction endpoint. Sediments were analyzed for physical and chemical characteristics, including particle size distribution, total organic carbon, acid volatile sulfide, slag content, and concentrations of metals in total-recoverable and simultaneously-extracted fractions. Porewaters were separated by centrifugation and by peepers (diffusion samplers) and were analyzed for filterable metals, dissolved organic carbon, and major ions. These data are intended to be used to characterize concentration-response relationships between metals concentrations and toxicity endpoints and to estimate site-specific toxicity thresholds for select metals or metal mixtures. These thresholds will be used to evaluate risks or injuries to the benthic invertebrate community associated with exposure to contaminated sediments and to develop goals for remediation of sediments of the Upper Columbia River.

This data release provides water chemistry results and quality assurance data for samples collected from Great Lakes tributaries in the states of Minnesota, Wisconsin, Michigan, Indiana, Ohio, and New York. In total, 158 chemicals were analyzed which are primarily pharmaceuticals. Between one and four water samples were collected at 37 sampling locations between November 2017 and July 2018 resulting in a total of 87 environmental, 95 field replicate, and 15 field blank samples. Of the 158 chemicals analyzed, 23 chemicals were detected in at least one regular sample. Detections per site ranged from 0 to 12 chemicals at concentrations of 1.56 to 30900 nanograms per liter. Sample collection and analysis was performed by the U.S. Geological Survey and summarized in the associated journal article (https://doi.org/10.1002/etc.5403). More detailed method descriptions will be published in the future.

This data release provides water chemistry results and quality assurance data for samples collected from Great Lakes tributaries in the states of Minnesota, Wisconsin, Michigan, Indiana, Ohio, and New York. In total, 158 chemicals were analyzed which are primarily pharmaceuticals. Between one and four water samples were collected at 37 sampling locations between November 2017 and July 2018 resulting in a total of 87 environmental, 95 field replicate, and 15 field blank samples. Of the 158 chemicals analyzed, 23 chemicals were detected in at least one regular sample. Detections per site ranged from 0 to 12 chemicals at concentrations of 1.56 to 30900 nanograms per liter. Sample collection and analysis was performed by the U.S. Geological Survey and summarized in the associated journal article (https://doi.org/10.1002/etc.5403). More detailed method descriptions will be published in the future.

This data release includes concentrations of contaminants of emerging concern (CEC), by chemical class, for sites sampled within 25 river basins in the U.S. portion of the Great Lakes basin and associated watershed characteristics. The CEC data include concentrations in surface water and sediment samples that were collected during 2010-2014. During the first 3 years, sample sites near mostly urban areas were chosen. The last two years of study focused on other point sources and few nominal reference sites. Water and sediment samples were analyzed for a diverse suite of CECs including, but not limited to, pharmaceuticals, industrial chemicals, flame retardants, pesticides, fragrances, and plasticizers. Statistical models were developed to define the relationships between watershed characteristics within a river basin and the occurrence of specific CEC classes using boosted regression tree models.

This data release includes concentrations of contaminants of emerging concern (CEC), by chemical class, for sites sampled within 25 river basins in the U.S. portion of the Great Lakes basin and associated watershed characteristics. The CEC data include concentrations in surface water and sediment samples that were collected during 2010-2014. During the first 3 years, sample sites near mostly urban areas were chosen. The last two years of study focused on other point sources and few nominal reference sites. Water and sediment samples were analyzed for a diverse suite of CECs including, but not limited to, pharmaceuticals, industrial chemicals, flame retardants, pesticides, fragrances, and plasticizers. Statistical models were developed to define the relationships between watershed characteristics within a river basin and the occurrence of specific CEC classes using boosted regression tree models.

Two types of passive samplers for polychlorinated biphenyl (PCB) analysis were deployed in the Clinton River Area of Concern in 2019: semipermeable membrane devices for water and in-stream sediment samplers. Samplers were deployed in July 2019 and retrieved in August 2019. Additionally, bank sediment samples for PCB analysis were collected by the U.S. Geological Survey (USGS) in August 2019 and catch basin bottom material samples for PCB analysis were collected by LimnoTech in November 2019 under contract with the U.S. Army Corps of Engineers. These data are a part of a larger study and associated USGS report (https://doi.org/10.3133/sir20235030).

Two types of passive samplers for polychlorinated biphenyl (PCB) analysis were deployed in the Clinton River Area of Concern in 2019: semipermeable membrane devices for water and in-stream sediment samplers. Samplers were deployed in July 2019 and retrieved in August 2019. Additionally, bank sediment samples for PCB analysis were collected by the U.S. Geological Survey (USGS) in August 2019 and catch basin bottom material samples for PCB analysis were collected by LimnoTech in November 2019 under contract with the U.S. Army Corps of Engineers. These data are a part of a larger study and associated USGS report (https://doi.org/10.3133/sir20235030).

Under the Great Lakes Restoration Initiative, the U.S. Geological Survey Mercury Research Lab (USGS MRL) conducted a multiyear assessment of mercury across the Laurentian Great Lakes. Biannual sampling was conducted across all five lakes onboard the U.S. Environmental Protection Agency (US EPA) research vessel Lake Guardian (in years 2010–2014, 2018) at pelagic sampling locations established by the long-term US EPA Great Lakes monitoring program. In addition to the regularly scheduled biannual sampling, in September 2013 and 2014 Lake Michigan and Lake Erie (respectively) were sampled with increased focus on shallow nearshore locations. Throughout these sampling efforts, sediments, mussels, surface water, and plankton were collected from open-water locations within all five of the Great Lakes. Additionally, surface water from Great Lake tributaries were sampled by the USGS MRL and preceded (2005 or 2006) or overlapped (2010-2015) with the open lake sampling efforts. All surface water samples were analyzed for methylmercury, total mercury, and dissolved organic carbon. Plankton and mussel tissue were analyzed for methylmercury, total mercury, and carbon/nitrogen stable isotopes and concentrations (plankton only). Sediments were analyzed for methylmercury, total mercury, and carbon content.