EPA collected data in 2008 to evaluate the transport of mercury-contaminated water and sediment in the Carson River System in western Nevada. This report summarizes the analytical and field results from a pilot investigation performed to assess mercury contamination. Understanding the sources and transformations of mercury aided in planning future RI activities and pilot studies to assess mercury fate and transport in the Carson River and the Lahontan Reservoir. Soil samples from erosional banks along a 4-mile segment of the Carson River upstream of the Lahontan Reservoir were collected and analyzed in this pilot investigation to characterize mercury variability in exposed banks prone to erosion. This report presents the following information: Results of soil sampling and analysis, evaluation of data quality and compliance with the field sampling plan (FSP), discussion of the data, conclusions and recommendations for further study. The EPA is publishing this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU2 Remedial Investigation Report (EPA, 2017), which describes the nature and extent of contamination from the Site. The report contains the Human Health Risk Assessment and Ecological Risk Assessment. Literature and other source Hg data are summarized in the RI for surface waters, sediments, and biological tissues.

In order to collect samples which represent the levels of mercury occurring on the flood plain above Lahontan Reservoir, EPA collected surface and subsurface samples along several transects. Samples were collected along 3 transects which extended across the flood plain, perpendicular to the direction of flow. All of the transects were located below Brunswick Canyon in Dayton and Churchill Valley where the flood plain is most expansive and where there were no mills. Along each transect, 10 surface soil samples were collected and analyzed for total mercury. At the Fort Churchill gage, samples were also collected from the different stratigraphic intervals apparent in the bank of the flood plain (i.e., "FP005"). The EPA is publishing this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU2 Remedial Investigation Report (EPA, 2017), which describes the nature and extent of contamination from the Site. The report contains the Human Health Risk Assessment and Ecological Risk Assessment Reports. Literature and other source Hg data are summarized in the RI for surface waters, sediments, and biological tissues.

In order to collect samples which represent the levels of mercury occurring on the flood plain above Lahontan Reservoir, EPA collected surface and subsurface samples along several transects. Samples were collected along 3 transects which extended across the flood plain, perpendicular to the direction of flow. All of the transects were located below Brunswick Canyon in Dayton and Churchill Valley where the flood plain is most expansive and where there were no mills. Along each transect, 10 surface soil samples were collected and analyzed for total mercury. At the Fort Churchill gage, samples were also collected from the different stratigraphic intervals apparent in the bank of the flood plain (i.e., "FP005"). The EPA is publishing this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU2 Remedial Investigation Report (EPA, 2017), which describes the nature and extent of contamination from the Site. The report contains the Human Health Risk Assessment and Ecological Risk Assessment Reports. Literature and other source Hg data are summarized in the RI for surface waters, sediments, and biological tissues.

In order to collect samples which represent the levels of mercury occurring on the flood plain above Lahontan Reservoir, EPA collected surface and subsurface samples along several transects. Samples were collected along 3 transects which extended across the flood plain, perpendicular to the direction of flow. All of the transects were located below Brunswick Canyon in Dayton and Churchill Valley where the flood plain is most expansive and where there were no mills. Along each transect, 10 surface soil samples were collected and analyzed for total mercury. At the Fort Churchill gage, samples were also collected from the different stratigraphic intervals apparent in the bank of the flood plain (i.e., "FP005"). The EPA is publishing this data in support of the Carson River Mercury NPL Site in Nevada. Data was compiled and evaluated for the OU2 Remedial Investigation Report (EPA, 2017), which describes the nature and extent of contamination from the Site. The report contains the Human Health Risk Assessment and Ecological Risk Assessment Reports. Literature and other source Hg data are summarized in the RI for surface waters, sediments, and biological tissues.

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.

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.

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.

This feature class is converted from GPS coordinates obtained using a GPSmap 60CSx unit from Garmin in the field by AEI Consultants. The attribute information is filled with contaminant (Arsenic, Lead, Mercury) concentrations of soils derived from the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013. For more information on soil sampling field procedures, refer to the following source documents: AEI Consultants, Peter J. McIntyre, C.E.M., October 16, 2012, Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada, report to Jack Yates, NDEP, Unpublished, AEI Consultants, Bryan Campbell, Program Manager, October 31, 2012, Identification of Revisions to the Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada date October 16, 2012, Electronic mail correspondence to Jeff Collins, NDEP, Unpublished, AEI Consultants, Peter J. McIntyre, C.E.M., January 11, 2013, Shallow Subsurface Investigation, Property Identification: Carson River Estates, Dayton, Nevada, report to Chris Carlson, Sr. Vice-President, City National Bank, Unpublished. Note: Generally, five composite sample points are respectively collected at the front and backyard in one parcel. However errors occurred in two parcels: APN=2952402 and APN=2952202. In the parcel 2952402, there are nine sample points. The other sample point (Sample ID=524-02-05) is found at the parcel 2952202 and overlied with one sample points (Sample ID=522-02-04) of the parcel 2952202. According to checking the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013, the originial GPS coordinates of both sample points (Sample ID=524-02-05 and Sample ID=522-02-04) are the same.

This feature class is converted from GPS coordinates obtained using a GPSmap 60CSx unit from Garmin in the field by AEI Consultants. The attribute information is filled with contaminant (Arsenic, Lead, Mercury) concentrations of soils derived from the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013. For more information on soil sampling field procedures, refer to the following source documents: AEI Consultants, Peter J. McIntyre, C.E.M., October 16, 2012, Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada, report to Jack Yates, NDEP, Unpublished, AEI Consultants, Bryan Campbell, Program Manager, October 31, 2012, Identification of Revisions to the Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada date October 16, 2012, Electronic mail correspondence to Jeff Collins, NDEP, Unpublished, AEI Consultants, Peter J. McIntyre, C.E.M., January 11, 2013, Shallow Subsurface Investigation, Property Identification: Carson River Estates, Dayton, Nevada, report to Chris Carlson, Sr. Vice-President, City National Bank, Unpublished. Note: Generally, five composite sample points are respectively collected at the front and backyard in one parcel. However errors occurred in two parcels: APN=2952402 and APN=2952202. In the parcel 2952402, there are nine sample points. The other sample point (Sample ID=524-02-05) is found at the parcel 2952202 and overlied with one sample points (Sample ID=522-02-04) of the parcel 2952202. According to checking the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013, the originial GPS coordinates of both sample points (Sample ID=524-02-05 and Sample ID=522-02-04) are the same.

This feature class is converted from GPS coordinates obtained using a GPSmap 60CSx unit from Garmin in the field by AEI Consultants. The attribute information is filled with contaminant (Arsenic, Lead, Mercury) concentrations of soils derived from the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013. For more information on soil sampling field procedures, refer to the following source documents: AEI Consultants, Peter J. McIntyre, C.E.M., October 16, 2012, Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada, report to Jack Yates, NDEP, Unpublished, AEI Consultants, Bryan Campbell, Program Manager, October 31, 2012, Identification of Revisions to the Draft Phase II Subsurface Investigation Work Plan Carson River Estates, Dayton, Nevada date October 16, 2012, Electronic mail correspondence to Jeff Collins, NDEP, Unpublished, AEI Consultants, Peter J. McIntyre, C.E.M., January 11, 2013, Shallow Subsurface Investigation, Property Identification: Carson River Estates, Dayton, Nevada, report to Chris Carlson, Sr. Vice-President, City National Bank, Unpublished. Note: Generally, five composite sample points are respectively collected at the front and backyard in one parcel. However errors occurred in two parcels: APN=2952402 and APN=2952202. In the parcel 2952402, there are nine sample points. The other sample point (Sample ID=524-02-05) is found at the parcel 2952202 and overlied with one sample points (Sample ID=522-02-04) of the parcel 2952202. According to checking the Shallow Subsurface Investigation provided by AEI Consultants dated on January 11, 2013, the originial GPS coordinates of both sample points (Sample ID=524-02-05 and Sample ID=522-02-04) are the same.