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Case Study Palos Verdes Shelf

Explore the Passive Sampling Activities, Advantages, Lessons Learned, Cleanup Progress, and Next Steps of the Palos Verdes Shelf Study conducted by Dr. Loretta Fernandez and EPA. Learn about Water Column and Sediment Flux Studies.

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Case Study Palos Verdes Shelf

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  1. Case Study Palos Verdes Shelf Judy C. Huang, P.E.

  2. Pore water and Bioavailability Course

  3. Outline • Site Location and History • Passive Sampling Activities and Results • Advantages of Passive Sampling • Lessons Learned • Site Cleanup Progress • Next Steps

  4. Location Map

  5. *Courtesy of Sanitation Districts of Los Angeles

  6. 2009 Interim Record of Decision • Institutional Controls • Monitored Natural Recovery • Clean Sediment Cap

  7. Passive Sampling Activities • Conducted by Dr. Loretta Fernandez through EPA Office of Research and Development • 2010 Water Column Study • 2011 Sediment Flux Study

  8. 2010 Water Column Study • Objective: Measure Water Column Contaminant Concentrations • Study Design: 12 Stations, 3 Depths (Bottom, Mid Column, and Surface) • Sampling Media: Microextraction (SPME) Fibers , and PRC Preloaded Solid Phase Polyethylene (PE) Strips • Target Contaminants: DDT Congeners, DDD, DDE, DDMU, DDNU and 43 PCB Congeners • Study Period: Deployed in September 2010 for 32 Days

  9. Water Column Study Sampling Locations *Environ. Sci. Technol. 2012, 46, 11937−11947

  10. Passive Sampling Rig Assembly Buoy Water Surface surface PSDs Line 30 - 35 m from surface 5 m from bottom Anchor Sediment Bed

  11. p,p’ DDE (SPME) *Environ. Sci. Technol. 2012, 46, 11937−11947

  12. p,p’ DDE (PE) *Environ. Sci. Technol. 2012, 46, 11937−11947

  13. Sum of PCB Concentrations (PE) *Environ. Sci. Technol. 2012, 46, 11937−11947

  14. 2011 Sediment Flux Study Objectives • Investigate effects of pilot sand cap on the flux of DDTs and PCBs from sediment to the water column using passive sampler derived concentration gradients • Observe concentrations of dissolved DDTs and PCBs in pore water as a function of depth • Compare the performance of different types of polymeric passive samplers

  15. 2011 Sediment Flux Study Design • 6 Stations • PRC Preloaded Solid Phase Microextraction (SPME) Fibers, Polyoxymethylene (POM) and Polyethylene (PE) Strips • DDT Congeners, DDD, DDE, DDMU, and PCB Congeners • Deployed in July 2011 for 44 Days

  16. Flux Study Sampling Locations *Environ. Sci. Technol. 2014, 48, 3925−3934

  17. Flux Platform Design

  18. Flux Platform *Photo Courtesy of Sanitation Districts of Los Angeles County

  19. Flux Platform Deployment *Photo Courtesy of Sanitation Districts of Los Angeles County

  20. Flux Platform Deployment • *Photo Courtesy of Sanitation Districts of Los Angeles County

  21. Flux Platform Retrieval *Photo Courtesy of Sanitation Districts of Los Angeles County

  22. p,p’ DDE (PE Average) Flux Rate (ng/ cm2y) Depth (cm) *Environ. Sci. Technol. 2014, 48, 3925−3934

  23. p,p’ DDD (PE Average) Flux Rate (ng/ cm2y) Depth (cm) *Environ. Sci. Technol. 2014, 48, 3925−3934

  24. p,p’ DDMU (PE Average) Flux Rate (ng/ cm2y) Depth (cm) *Environ. Sci. Technol. 2014, 48, 3925−3934

  25. PCB 52 (PE Average) Flux Rate (ng/ cm2y) Depth (cm) *Environ. Sci. Technol. 2014, 48, 3925−3934

  26. Advantages of Passive Sampling • Does not require collection of a large quantity of water per sample • Time and Cost Saving: two deployments vs. multi-day water collection • Data represents only the dissolved and bioavailable fraction of contaminants of concern • Allows calculation of flux rate • Ability to measure water column pollutant concentrations immediately above seabed

  27. Advantages of Passive Sampling • Allows EPA to evaluate feasibility of remedial options • Allows EPA to monitor for remedy effectiveness

  28. Lessons Learned • Not all passive samplers are created equal • Choice of sampling media determined by Contaminant of Concern • Be aware of site conditions • Sample rig design and placement should be based on actual site conditions

  29. Cleanup Status • Suspended cap design, since post capping IROD goals appear to have been achieved • Monitored Natural Attenuation is occurring • Appeared to reach IROD fish tissue goals for DDTs but not PCBs • Met IROD sediment goals for PCBs in Sediment but not for DDTs • Not enough information to determine water column compliance progress

  30. Next Steps • Sediment Analysis • 69 Locations • Analytes: DDT related compounds and 28 PCB congeners • Water Column Analysis • Passive sampling in 17 locations • High Resolution GC/MS Analysis Pilot Study: Sample collection at all passive sampler deployment location plus 35 sediment baseline locations

  31. Next Steps (cont.) • Fish Tissue Analysis • White croaker and barred sand bass in multiple locations • Skin-off fillet to be analyzed and whole fish concentration to be calculated using PV Shelf specific translators.

  32. Acknowledgement • Loretta Fernandez, Northeastern University • Robert Burgess, EPA ORD • Chi-Li Tang, Sanitation Districts of Los Angeles • Joe Gully, Sanitation Districts of Los Angeles • Keith Maruya, Southern California Coastal Water Research Project • Robert Lindfors, Gilbane

  33. Questions?

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