The data set contains the raw data used to develop the figures and tables associated with the published manuscript. This dataset is associated with the following publication: Eckley , C., T. Luxton , J. McKernan , J. Goetz , and J. Goulet. Influence of Reservoir Water-Level Fluctuations on Mercury Methylation Downstream of the Historic Black Butte Mercury Mine, OR. Michael Kersten APPLIED GEOCHEMISTRY. Elsevier Science Ltd, New York, NY, USA, 61: 284-293, (2015).

Figures 2, 3 and 4 as well as Figures S2 and S3 in the Supporting Information include data collected by (or for) the EPA at the Black Butte Mine Superfund Site. All other data in the above mentioned Figures (as well as all other Figures/Tables in the paper) were obtained from previously published journal articles or were obtained from publicly available websites. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

The movement of mercury (Hg) from the atmosphere to the biosphere occurs by both wet and dry deposition to solid surfaces, water, and vegetation. Most of the annual dry atmospheric Hg deposition in deciduous forests is believed to originate from litterfall which consists mainly of dead leaves that fall to the earth’s surface, primarily during the autumn and winter seasons. Atmospheric Hg reaches an annual maximum concentration in leaves at the time of leaf fall. Analysis of litterfall samples helps to quantify total annual atmospheric Hg deposition to forests when combined with precipitation Hg data. This data set is derived from litterfall samples collected during 2017-18 and 2018-19 at 27 selected National Atmospheric Deposition Program (NADP) sites in 12 states located across the eastern half of the United States. Through the Litterfall Mercury Monitoring Initiative (LMMI), operated by the U.S. Geological Survey (USGS), litterfall sample collectors were distributed to the selected NADP sites where site operators retrieved multiple 4-week-long samples during the leaf fall period. These samples were collected and shipped to the USGS Mercury Research Laboratory where they were analyzed for concentrations of total Hg and methylmercury (MeHg), and litterfall dry mass was also determined. The samples for total Hg and MeHg analysis represent composites from 4 collectors across all sample collections at each site during the litterfall season. Litterfall dry mass was determined from all 8 sample collectors across all sample collections.

Metadata. This dataset is associated with the following publication: Jesus Eulisis, C., M.d.C. Gonzalez-Chavez, R. Carrillo-Gonzalez, K. Scheckel, D. Tapia Maruri, and J. Garcia Cue. Metal(loid) bioaccessibility of atmospheric particulate matter from mine tailings at Zimapan, Mexico. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH. Ecomed Verlagsgesellschaft AG, Landsberg, GERMANY, 28: 19458-19472, (2021).

The data set contains a summary of all measurements that were collected at the cottage grove reservoir over the time period of the study. This dataset is associated with the following publication: Eckley, C., T. Luxton, J. Goetz, and J. McKernan. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.. David Carpenter, and Eddy Zeng ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 222: 32-41, (2017).

EPA/NOAA Mauna Loa Observatory Daily Gaseous Elemental Mercury (GEM) data 2002-2010. This dataset is associated with the following publication: Feinberg, A., N. Selin, C. Braban, K. Chang, D. Cust�dio, D. Jaffe, K. Kyll�nen, M. Landis, S. Leeson, K. Molepo, M. Murovec, M. Nerentorp Mastromonaco, K. Aspmo Pfaffhuber, J. R�diger, G. Sheu, and V. St.Louis. Increasing anthropogenic emissions inconsistent with declining atmospheric mercury concentrations. PNAS (PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES). National Academy of Sciences, WASHINGTON, DC, USA, 0, (2024).

Metadata. This dataset is associated with the following publication: Jesus Eulisis, C., M.d.C. Gonzalez-Chavez, R. Carrillo-Gonzalez, J.L. Garcia-Cue, D. Fernandez-Reynoso, M. Noerpel, and K. Scheckel. Bioaccessibility of potentially toxic elements in mine residue particles. Environmental Science: Processes & Impacts. RSC Publishing, Cambridge, UK, 23(2): 367-380, (2021).

EPA evaluated the total mercury representative of several surface and subsurface locations in OU1 for the purpose of the Human Health Risk Assessment investigation. EPA published this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU1 Remedial Investigation Report (EPA, 1994), which describes the nature and extent of contamination from the Site. The reports contain the Human Health Risk Assessment and Ecological Risk Assessment Reports. Literature and other source Hg data are summarized in the RI report for upland source areas.

EPA evaluated the mercury fractions (species) representative of several locations in OU1 for the purpose of the Human Health Risk Assessment investigation. In particular, the mercuric chloride fraction was of interest to toxicologists, because this is most bioavailable form of the compound in the terrestrial food pathway. EPA published this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU1 Remedial Investigation Report (EPA, 1994), which describes the nature and extent of contamination from the Site. The reports contain the Human Health Risk Assessment and Ecological Risk Assessment Reports. Literature and other source Hg data are summarized in the RI report for upland source areas.

This dataset contains final results for XRF and select laboratory results for the 2019 Carson River Mercury Site Incremental Sampling Field Study. Incremental samples were collected from three separate areas within the CRMS: Six Mile Canyon Area near Mark Twain, NV; California Pan Mill in Virginia City, NV; and Sacramento Mill in Virginia City, NV. The purpose of the data collection was to help characterize the extent of Hg, Pb, and As in surface (0 to 6-inch) and in some locations subsurface (0 to 24-inch) soils in the three study areas. A secondary purpose of the study was to demonstrate incremental sampling techniques and field XRF analysis to EPA Region 9 and NDEP Staff. The XRF results columns in the attribute table were generated by XRF data collected in accordance with the EPA-Approved Quality Assurance Project Plan and are considered definitive results suitable for project decisions. 30-point incremental samples were sieved to the 100-mesh fraction, placed “interference free” XRF read bags, and analyzed with EPA Headquarters’ Niton XRF. At least two XRF measurements were collected on each side of the bag resulting in at least four readings that were used to calculate the sample bag average that appears in the XRF Results columns for Hg, Pb, and As. If triplicate results were collected for a given sample, the mean is reported in the XRF Results columns for Hg, Pb, and As and the results for each of the three replicates are detailed in the XRF Notes column.