Mercury in Reservoirs the Topic of Meetings

On Wednesday, October 25, The Sierra Fund will hold it’s second quarterly Technical Advisory Committee meeting for the Headwater Mercury Source Reduction program (HMSR-TAC). The meeting will feature four presentations on the topic of mercury-contaminated sediment in reservoirs.

During the California Gold Rush, mercury was used in mining operations to aid in gold recovery. Today, every storm event washes sediment and mercury from contaminated legacy sites into creeks and rivers. This material flows downstream and accumulates in reservoirs, reducing water storage capacity and impacting the food web with methylated mercury which can both bioaccumulate and biomagnify in fish. This HMSR-TAC meeting will address a pilot project and associated research currently being implemented at Lake Combie on the Bear River to remove mercury-contaminated sediment in order to restore water storage capacity and reduce mercury concentrations in the watershed.

The subject matter is timely in light of the State Water Resources Control Board’s (SWRCB) meetings for owners and operators of mercury-impaired reservoirs in California. The first SWRCB meeting took place on October 11, in conjunction with the California Lake Management Society‘s annual conference. A second meeting is scheduled for Thursday, November 2 from 10:00 am – 12:00 pm at the CalEPA building in Sacramento.

Participants at the SWRCB meeting will discuss the Statewide Mercury Control Program for Reservoirs being developed by the Water Board to address the negative impacts of mercury to 132 impaired reservoirs in the state. The goal of the program is to restore reservoirs so the public can enjoy the full beneficial uses, including fish consumption, of these water bodies.

The pilot project at Lake Combie demonstrates emerging technology that may be suitable for deployment in other mercury-impaired reservoirs across the state, thus helping to meet the objectives of the Statewide Mercury Control Program. The Sierra Fund advocated for funding, to the tune of $6.13 million, that was approved in California’s 2017/2018 budget to transition to full-scale operations at Lake Combie, and we look forward to supporting this project as a strategy to mitigate the impacts of headwater sources of mercury. Read about the budget allocation here.

To learn more about TSF’s Headwater Mercury Source Reduction Technical Advisory Committee (HMSR-TAC), visit:

For more information on the SWRCB’s Mercury Control Program for Reservoirs, visit: