BLM and USGS begin geothermal monitoring well installation in Mammoth Lakes

MAMMOTH LAKES, Calif. — Crews from the U.S. Geological Survey Research Drilling Unit, working on behalf of the Bureau of Land Management Bishop Field Office, have started installing a geothermal monitoring well in Mammoth Lakes on National Forest System lands in the northwest portion of the Old Shady Rest Campground.

Residents and visitors should anticipate increased activity at and near the well site, including increased vehicle traffic on State Route 203 (Main Street, Sawmill Cutoff Road and Forest Trail Road), as USGS mobilizes and works to complete the well.

Drilling operations are planned for 12-hours per day, seven days per week, during the first two weeks of well installation. Beginning in early May, operations will be ramped up to 24-hours per day to ensure well completion prior to opening the campground for the summer. All roads and recreational trails in the area will remain open for public use during drilling.

The BLM Bishop Field Office, in close coordination with the Inyo National Forest Mammoth Ranger District, approved the well installation to support the Groundwater Monitoring and Response Plan for the Casa Diablo IV (CD-IV) Geothermal Development Project. The CD-IV Project is located on a BLM-administered federal geothermal lease located within the Inyo National Forest in Mono County.

“Participation in the BLM required monitoring and response plan for the CD-IV Project has increased substantially since July 2019,” said Bishop Field Manager Steve Nelson. “I am pleased to report that both Ormat, the owner and operator of the CD-IV Project, and the Mammoth Community Water District have agreed to assist and support us in a collaborative effort to drill and instrument the Old Shady Rest monitoring wells.”

Once operational, the CD-IV power plant will provide a clean, dependable energy source and produce 30 megawatts of electricity to power up to 22,000 homes, while offsetting 4 million tons of carbon dioxide emissions. The Old Shady Rest monitoring wells will be incorporated into the BLM approved groundwater monitoring and response plan for the project. The goal of that plan is to provide increased certainty that CD-IV plant operations will not have an adverse effect on the municipal water supply for the town of Mammoth Lakes.

For more information regarding the monitoring well project, please contact BLM Bishop Field Office Geologist Jason Titus at 760-872-5012.