The USGS collects data for this national program to inform public, State and local governments, public and private utilities and other Federal agencies involved with managing water resources. The NWIS Mapper provides the ability to export descriptive information and access data for most water-data sites in the National Water Information System (NWIS). These sites are or have been operated by USGS or in some cases by its cooperative partners. Includes methyl and elemental Hg in surface water. USGS Water Quality and Bottom Sediment Data, Co-located with Higgins, and Tuttle samples, and includes additional USGS gauges at Dayton, Lloyds Bridge, Weeks Bridge, Ft Churchill, BLW Lahonton Dam, and Fallon Canals.

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.