Carrie Monohan, Ph.D

Grass Valley, Calif. April 24, 2018 – Free Science Presentation at the Sierra College Nevada County Campus, Tuesday, May 8 from 6:30 to 7:30pm.

Find out about mercury in Sierra watersheds, a legacy of the California Gold Rush, during which time more than ten million pounds were applied at mining operations to aid in gold recovery. 10 to 30 percent of this mercury was lost to the environment, posing a threat to the environment and public health today.

The storm runoff from the Malakoff Diggins hydraulic mine discharges into nearby creeks, contributing significant loads of sediment and mercury as it flows into the Wild and Scenic South Yuba River. Mercury-contaminated sediment accumulates in reservoirs, and the Nevada Irrigation District’s project to remove this material from Combie Reservoir on the Bear River is an innovative approach to addressing legacy contamination.

Dr. Carrie Monohan will discuss how our state can address mercury left over from the Gold Rush, and will explore strategies and the multiple benefits associated with removing contaminated sediment to restore reservoirs across the Sierra Nevada.

About the Presenter

Carrie Monohan, Ph.D., is the science director at The Sierra Fund (TSF). She executes TSF’s Ecosystem Resiliency Program, which addresses ongoing mining impacts on water quality, forest health, meadows and fish passage. For over 10 years, Dr. Monohan has researched the effects of the Gold Rush in the Sierra Nevada. Her assessment techniques and efforts to prioritize mine-scarred lands have helped shape statewide efforts to reduce mercury discharge from California’s headwaters.

Dr. Monohan is an Adjunct Professor in the Geological and Environmental Sciences Department at CSU Chico, where she builds the capacity of early career scientists by integrating graduate student research into the projects that she directs at TSF. Her projects include work at Malakoff Diggins and management of sediment and mercury from Combie Reservoir.

Location and Parking

The Nevada County Campus is located at 250 Sierra College Drive, Grass Valley, CA 95945. Talks are in the Multipurpose Center Building N-12.

Parking is $3, and you can purchase permits at the kiosk machine at the main entrance to the campus.

For more information, contact the series coordinator, Jason Giuliani, at

About Sierra College

Sierra College District is rising to meet the needs of our community, serving 3200 square miles of Northern California with campuses in Roseville, Rocklin, Grass Valley and Truckee. With over 120 degree and certificate programs, Sierra College is Northern California’s top community college for transfers to four-year universities and offers career/technical training and classes for upgrading job skills. Sierra graduates can be found in businesses and industries throughout the region. More information at