Statewide Mercury Program
Addressing Mercury in California's Waters
Many of California’s waters are contaminated by mercury (also called quicksilver), a heavy metal and potent neurotoxin that is harmful to both humans and wildlife. Mercury builds up in the bodies of fish that swim in waters with even small amounts of mercury; and in the bodies of humans who eat contaminated fish. In our state, sources of mercury typically include:
- Historic mercury and gold mining activities
- Atmospheric deposition from both local and global airborne sources
- Discharges from wastewater treatment plants that cannot remove mercury from industrial processes or mercury thermometers broken in a sink
Ongoing State Efforts to Address Mercury
The California Department of Public Health and the Office of Environmental Health Hazard Assessment are educating people who eat local fish, about the types and amounts of fish that are safe and unsafe to eat.
Women of childbearing years and children are most at risk from mercury poisoning. For more information, see Safety Tips for Women and Children and General Health Advice for People Catching and Eating Sport Fish in California.
Development of a statewide Mercury Policy and new fish tissue objectives continue efforts by the State Water Resources Control Board and the nine Regional Water Quality Control Boards to reduce concentrations of mercury in our waters.
New! Update on Mercury Programs (April 23, 2013 Board Meeting Presentation) During the April 23 Board Meeting, Water Board staff presented an update on recently adopted mercury TMDLs and on the developing Statewide Mercury Program.
Statewide Mercury Control Program for Reservoirs
Water Board staff from around the state are working to develop a regulatory program to address mercury contamination in California reservoirs, as part of a larger Policy to control mercury in all of the state’s waters. In compliance with the California Environmental Quality Act (CEQA), four public scoping meetings were held in March 2012.
- CEQA Scoping Notice
- Public Scoping Presentation
- Project Summary
- Map and list of California reservoirs impaired by mercury
- Control Program for Mercury in California’s Reservoirs fact sheet
Following the meetings, interested stakeholders including reservoir operators and water agencies from around the state submitted written comments. While the Water Board is not required to respond formally to scoping comments, we will take them into account as we move forward to develop the Policy.
Next Steps for Reservoirs
Staff is currently working on the technical analysis for the project (conceptual model, source analysis, linkage between sources and fish tissue concentrations, and implementation ideas) and drafting a regulatory program. Public meetings to present and discuss details of the project will be scheduled for fall/winter 2012–2013. Meeting announcements will be posted on this website and sent via e-mail, so please scroll up and “subscribe to updates” if you are not already subscribed.For more information about the program, email MercuryProject@waterboards.ca.gov, or Carrie Austin, or phone (510) 622-1015.
The State Water Board is developing a set of standards (“objectives”) for safe amounts of methylmercury in the tissues of fish. These objectives will inform mercury policy, mercury pollution prevention plans, and water quality permits. They will apply to California’s inland waters, enclosed bays, and estuaries; and protect humans and wildlife that consume locally caught fish.
- Development of Methylmercury Objectives
Drafted informational document from public scoping meeting (2007).
- Public Comments Received (February 2007)
No meetings are scheduled at this time. Watch this page for more information!
The Water Boards adopt and implement comprehensive pollution control plans, known as “total maximum daily loads,” or TMDLs. A TMDL identifies
the amount of a pollutant that a water body can hold and still be safe for uses by humans and wildlife.
Completed Mercury TMDLs (including date approved by U.S. EPA)
- Clear Lake Mercury TMDL (Central Valley Region, 2003)
- Guadalupe River Watershed Mercury TMDL (San Francisco Bay Region, 2010)
- Los Angeles Area Lakes TMDLs (Los Angeles Region, established by the U.S. Environmental Protection Agency)
- Walker Creek Watershed Mercury TMDL (San Francisco Bay Region, 2008)
Other Completed Mercury TMDLs (including date approved by U.S. EPA)
- Cache Creek, Bear Creek, and Harley Gulch Mercury TMDL (Central Valley Region, 2007)
- Sacramento-San Joaquin River Delta Methylmercury TMDL (Central Valley Region, 2011)
- San Francisco Bay Mercury TMDL (San Francisco Bay Region, 2008)
- Sulphur Creek Mercury TMDL (Central Valley Region, 2009
Mercury TMDLs in Development
- Big Bear Lake Mercury TMDL (Santa Ana Region)