RESOURCES

San Francisco Bay Mercury TMDL

U.S. EPA gives final approval to TMDL for Mercury in San Francisco Bay

On February 12, 2008, the federal Environmental Protection Agency approved a Basin Plan amendment incorporating a TMDL for mercury in San Francisco Bay and an implementation plan to achieve the TMDL. The amendment was formerly adopted by the San Francisco Bay Water Board, the State Water Resources Control Board, and the state Office of Administrative Law. It is now officially incorporated into the Water Quality Control Plan for the San Francisco Bay Basin (Basin Plan), the region's master planning document for protecting water quality.
Download State Board's Resolution R2-2007-0045

Documents
The San Francisco Bay Mercury TMDL was considered and adopted by the Water Board at hearings in September 2004 and August 2006. Follow the links below to agendas for those hearings, which link in turn to all relevant materials including Water Board resolutions.

August 9, 2006 Water Board hearing, Item 7
Adopted Resolution R2-206-0052
Approved Basin Plan amendment with appendices, showing changes since September 2004 (pdf, 230 kb )
Final Staff Report (pdf, 1.3 mb )

September 15, 2004 Water Board hearing, Item 10

TMDL Implementation

Watershed Permit for municipal and industrial wastewater discharges of mercury to San Francisco Bay
For more information, please see materials presented to the Water Board at the permit adoption hearing, November 1, 2007.

Bay Area Petroleum Refineries - Fate of Crude Oil Mercury
The mercury TMDL implementation plan identified an information gap associated with Bay Area petroleum refineries. The information gap was an apparent mismatch between the potentially large amount of mercury entering the refineries in crude oil and the much smaller quantity of mercury that could be accounted for leaving refineries in various product and waste streams. In 2007, the Executive Officer of the Water Board formally ordered (download the Water Board's 13267 order to the refineries) the petroleum refineries to submit technical reports to address this information gap, and the final report for the study was received in June 2009 (click here to download report, 5.2Mb).

The study results suggest that about 220 kg/yr of mercury enters petroleum refineries in crude oil. This amount, based on actual measurements of mercury in crude oil, is much less than the amount estimated by staff using literature values for mercury concentration in crude oil. The mass balance also suggests that, by far, the majority of this mercury leaves the refineries in solid waste that is transferred to off-site solid waste disposal facilities. Less than 10% of the input mercury is emitted directly to the air from stacks, and roughly 10% of the mercury leaves the petroleum refineries in various products like automobile fuel and fuel oil. Small amounts were also contained in petroleum coke (1%) and wastewater (< 1%).

Discharge permit for wastewater sources of mercury
On November 1, 2007, the Water Board adopted a Watershed Permit (Order No. R2-2007-0077) for industrial wastewater and municipal wastewater discharges identified in the SF Bay Mercury TMDL implementation plan. This Watershed Permit implements the wasteload allocations for these two source categories. It also implements other provisions of the TMDL requiring pollution prevention, special studies, and risk reduction actions to be conducted by the permittees. The Watershed Permit may become effective as soon as January 1, 2008, although the effective date may be delayed if the U.S. EPA does not approve the TMDL by this date.

Municipal Regional Permit
The NPDES Municipal Regional Permit is a permit for all municipal stormwater programs in the Bay Area. This permit will implement all mercury-related control measures and wasteload allocations required by the TMDL for stormwater sources. To find out more about the status and details of this permit, click here.

Methylmercury data from wastewater effluent
In June 2006 the Water Board issues a requirement letter to all municipal and industrial wastewater treatment facilities in the region. The letter required the facilities to conduct monthly measurements of methylmercury concentrations in wastewater effluent for one year, and submit the results to the Water Board. With this information we will be able to compare the amount of methylmercury coming from wastewater to data on other sources, as they become available. To see a copy of this letter, click here.

Background

San Francisco Bay supports beneficial uses, such as sport fishing and habitat for wildlife and endangered species. Fish tissue collected from San Francisco Bay often contains relatively high concentrations of mercury. The California Office of Environmental Health Hazard Assessment has issued fish consumption advisories warning people to limit their consumption of San Francisco Bay fish. In addition, studies have shown that birds consuming fish and other organisms from San Francisco Bay pass mercury to their eggs, potentially contributing to reproductive failures.

The San Francisco Bay Mercury TMDL Project examines this water quality problem and identifies sources of mercury. Sources of mercury include runoff from historic mines, urban runoff, wastewater discharges, atmospheric deposition, and resuspension of historic deposits of mercury-laden sediment already in San Francisco Bay. Most of the historic mercury deposits date back to the Gold Rush of the 1800's, when mercury was mined throughout the Coastal Range and used in the Sierra Nevada to extract gold. The single largest source is the Central Valley, where rivers carry mercury from remote regions of California to San Francisco Bay.

Links

U.S. Environmental Protection Agency
Mercury Study Report to Congress
Wisconsin Mercury Sourcebook
Draft PBT National Action Plan for Mercury

U.S. Geological Survey
Mercury in the Environment fact sheet
Mercury Contamination of Aquatic Ecosystems fact sheet

Other
Delta Tributaries Mercury Council (Sacramento River Watershed Program)
California Sport Fishing Health Advisories (CA Office of Environmental Health Hazard Analysis)
City of Palo Alto Mercury Publications

For more information contact:

Carrie Austin
San Francisco Bay Regional Water Quality Control Board
1515 Clay Street, Suite 1400
Oakland, CA 94612
Phone: 510-622-1015
Fax: 510-622-2460

Richard Looker
Water Resources Control Engineer
San Francisco Bay Regional Water Quality Control Board
1515 Clay Street, Suite 1400
Oakland, CA 94612
Phone: 510-622-2451
Fax: 510-622-2460