The State Water Resources Control Board and Regional Water Quality Control Boards (Water Boards) are in the early stages of developing a Statewide Mercury Policy to control mercury in California’s waters. The Policy would define an overall structure for adopting water quality objectives; general implementation requirements; and control plans for mercury impaired water bodies.
According to the Water Boards, the first phases of program development will include:
- Development of water quality standards to protect people and wildlife that eat fish. These could include water quality objectives expressed as concentrations of mercury in the water column or in the tissues of fish; beneficial use designations; and antidegradation provisions
- Establishment of a control program designed to attain the new water quality objectives in the state’s mercury-impaired reservoirs.
An associated implementation plan will likely include control actions for a variety of point and nonpoint sources, such as runoff from mine sites, atmospheric deposition, and discharges from wastewater treatment plants and urban stormwater. It could also propose changes in approaches to reservoir management that will modify water chemistry to reduce creation of the most biologically available form of mercury and changes in fisheries management practices to limit populations of the types of stocked fish that often have high levels of mercury in their tissues
Future phases may include development of control plans specific to other mercury-impaired water bodies such as creeks, rivers, bays, and estuaries.