Keith A. Kvenvolden

Geochemical studies of anthropogenic and natural organic compounds at the Sonoma Baylands Wetland Demonstration Project site and adjacent marshlands, Sonoma County, California

..................................................................................................... pg. 9 Introduction................................................................................. 11 Purpose and scope ...................................................................... 13 Study area...................................................................................... 14 Methods.................................................................................................... 15 Sample collection............................................................................ 15 Sample preparation and analysis ...................................................... 16 Elemental analyses.......................................................................... 17 Results and discussion ................................................................................ 17 Pilot site ......................................................................................... 17 Main site ........................................................................................ 24 Petaluma tidal marsh restoration project.......................................... 28 Adjacent marshland tidal marsh channels ......................................... 30 Conclusions............................................................................................... 34 Acknowledgment...................................................................................... 35 References................................................................................................. 35 FIGURES 1. Tidal wetlands in 1848 in San Francisco Bay ......................................... 65 2. Map showing location of the Sonoma Bay lands Demonstration Project site ................................................................................... 66 3. The Sonoma Baylands Wetland Demonstration Project........................ 67 4. The Petaluma Tidal Marsh Restoration Project..................................... 68 5. Distributions of aliphatic hydrocarbons in sediment cores from the Pilot site and the adjacent marshland reference sites ................................... 69 6. (a) Concentrations of total PAHs in surficial sediments of the Pilot and adjacent marshland reference sites. ER-L (Effects Range-Low) and ER-M (Effects Range-Medium) concentrations for total PAHs. (b) Concentrations of total DDTs in surficial sediments of the Pilot and adjacent marshland reference sites. ER-L (Effects Range-Low) and ER-M (Effects Range-Medium) concentrations for total DDTs .................... 70 7. Distributions of aliphatic hydrocarbons in sediment cores from the Main site, the Petaluma Tidal Marsh Restoration Project, and reference sites in the adjacent marshlands .................................................................. 71 8. (a) Concentrations of total PAHs in surficial sediments of the Main site and adjacent marshland reference sites. ER-L (Effects Range-Low) concentrations for total PAHs. (b) Concentrations of total DDTs in surficial sediments of the Main and adjacent marshland reference sites. ERL (Effects Range-Low) and (ER-M) Effects Range-Medium concentrations for total DDTs ....................................................... 72 9. (a) Concentrations of total PAHs in surficial sediments of the Petaluma tidal Marsh Restoration Project site. ER-L (Effects Range-Low) and ERM (Effects Range-Medium) concentrations for total PAHs. (b) Concentrations of total DDTs in surficial sediments of the Petaluma Tidal Marsh Restoration Project site. ER-L (Effects Range-Low) and ER-M (Effects Range-Medium) concentrations for total DDTs ......... 73 10. Sampling locations of benthic sediments in tidal marsh channels in the marshlands adjacent to the SBWDP site ........................................... 74 11. Distributions of aliphatic hydrocarbons in benthic sediments of tidal marsh channels in the marshland adjacent to the SBWDP site .............. 75 12. (a) Concentrations of total PAHs in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site. ER-L (Effects Range-Low) and ER-M (Effects Range-Medium) concentrations for total PAHs. (b) Concentrations of total DDTs in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site. ER-L (Effects Range-Low) and ER-M (Effects Range-Medium) concentrations for total DDTs ........................................................................... 76 13. Relation between total organic carbon (TOC) and total alkanes in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site ...................................................................................... 77 14. Relation between total organic carbon (TOC) and total PAHs in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site............................................................................. 78 15. Relation between total alkanes and total DDTs in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site ....... 79 16. Relation between total organic carbon (TOC) and total DDTs in benthic sediments of tidal marsh channels in the marshlands adjacent to the SBWDP site of tidal marsh channels in the marshlands ...................... 80