The U.S. Geological Survey (USGS) provides geologic, hydrologic, and other scientific and technical expertise required in the accomplishment of the U.S. Department of Energy’s (DOE) Defense Program (DP), Program Readiness and Environmental Protection/Hydrogeologic Services activities at the Nevada National Security Site (NNSS). The USGS provides hydrologic data that are used to develop groundwater supplies that support ongoing activities and assist in planning new activities on the NNSS.

Principal USGS objectives for Program Readiness activities are to:

• Support the USGS, NNSS Core Library & Data Center (CLDC), which is a repository for more than two million linear feet of core and cuttings collected mostly from the NNSS.
• Create high-resolution digital photographs of rock samples (core, cuttings, sidewall, and grab samples) stored in the CLDC.
• Scan petrographic thin sections and serve these images online.
• Estimate field-scale infiltration rates.

Principal USGS objectives for Environmental Protection/Hydrogeologic Services activities are to:

• Maintain a database of groundwater withdrawals from principal NNSS water-supply wells.
• Support future NNSS water resource development through continued monitoring of select sites that were part of the Yucca Mountain Environmental Monitoring Program (YMEMP) water-level network.
• Support the radio tracking of bighorn sheep and mountain lions on and off the NNSS.

Hydrologic Technician measuring depth to water with a calibrated electric tape in well UE-25 WT 12.