Mercury Transport to San Francisco Bay through the Sacramento-San Joaquin River Delta. Nicole David, Lester J. McKee, Jon E. Leatherbarrow December 15, 2005 Item #7

Sampling Event 2005 January 3 through 6, 2005

Sampling Event 2005 Max dayflow 58,000 cfs (Max dayflow so far 150,000 cfs)

Sampling Event 2005 Max HgT ng/L

Relationship between total Hg and SSC

Relationship between total Hg and SSC influenced by salinity

Annual Mercury Loads Water YearFlow (Mm 3 )Sediment (Mt)Mercury (kg) , ± ± , ± ± , ± ± , ± ± , ± ± , ± ± , ±0.0852± , ±0.1058± , ±0.1797± , ± ± *14, ±0.1164±22 Average27, ± ±61

Organic Contaminants *four samples collected in May 2003 had TPCB concentrations ranging from 890 – 6700 pg/L Item #7

Preliminary Loading Estimates Loads are preliminary and were estimated using Regression (REG) and Flow Weighted Mean Concentrations (FWMC). Preliminary estimates of errors are approximately ± 25%. PCBs PAHs FWMC Item #7

Project Sampling Schedule WY 2006: Collect first flush data and sample storm event over 150,000 cfs WY 2007: Sample storm event over 150,000 cfs only* WY 2008: Sample storm event over 150,000 cfs only* WY 2009: Sample all floods * With RMP contingency money

Project Reporting Schedule 2006 Final Report: 2002–2005 data 2009 Report sampling results and reinterpret existing data Item #7