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PCBs and PBDEs on the Guadalupe River WYs 2003 – 2006

Item #2b. PCBs and PBDEs on the Guadalupe River WYs 2003 – 2006. John Oram, Jon Leatherbarrow, and Lester McKee Sources Pathways and Loadings Workgroup November 13 th 2006. Item #2b. Methods for Estimating Loads of PCBs and PBDEs.

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PCBs and PBDEs on the Guadalupe River WYs 2003 – 2006

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  1. Item #2b PCBs and PBDEs on the Guadalupe RiverWYs 2003 – 2006 John Oram, Jon Leatherbarrow, and Lester McKee Sources Pathways and Loadings Workgroup November 13th 2006

  2. Item #2b Methods for Estimating Loads of PCBs and PBDEs • Examine relationship between instantaneous SSC and contaminant conc. • Examine spatial/temporal patterns of precip and Q at various locations in watershed to determine source. • Use 1 and 2 to build regression model(s) where appropriate. • Use regression model to estimate 15-minute concentrations. • Use 15-minute Q and 15-minute conc to calculate loads. Iterative Process

  3. Item #2b Sampling Frequency WY 03 (n=21) WY 05 (n=13) WY 04 (n=19) WY 06 (n=14)

  4. Item #2b Sampling Frequency

  5. Item #2b PCBs vs SSC (previous water years) WY 2005

  6. Item #2b PCBs vs SSC WY 2006 • Did not see ‘split’ regression this water year.

  7. Item #2b PBDEs vs SSCWY 2005

  8. Item #2b PBDE Concentrations, Discharge, and Instantaneous SSC

  9. Item #2b PBDEs vs SSCWY 2006 • Attempted to split regression by upper/lower/base flow designations. • Didn’t work this year for PBDEs or PCBs • Two Regressions: • All data • No Outlier

  10. Item #2b Previously Reported Loads

  11. Item #2b WY 2006 Loads

  12. Item #2b Source ID by PCB Homologs? Source activation of ‘new’ PCBs during high flow? Transport of weathered material? From WY05 Report

  13. Item #2b Source ID by PBDE Homologs?

  14. Item #2b How did WY05 and WY06 compare to previous years?

  15. Item #2b How did WY05 and WY06 compare to previous years?

  16. Item #2b April 2006 • 2.21 Kg PBDEs (52% of Seasonal Load) • 30% of 2.21 kg delivered on April 4th = 0.73 kg.

  17. Item #2b Annual Loading Estimates PBDE loads are 3-11x PCB loads. Sources: RMP special study on wastewater discharges; L. McKee; CARB (2005); D. Yee Estimates or Preliminary!

  18. Modeling PBDEs *Predicted inventories are consistent with those estimated from monitoring. Item #2b Model predictions are preliminary. Loads Source: J. Oram, SFEI

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