CONTRIBUTION NO. 867 JUNE 2018 Per and Polyfluoroalkyl Substances (PFASs) in San Francisco Bay: Synthesis and Strategy Prepared by Meg Sedlak, Rebecca Sutton, Adam Wong, and Diana Lin San Francisco Estuary Institute SAN FRANCISCO ESTUARY INSTITUTE • CLEAN WATER PROGRAM/RMP • 4911 CENTRAL AVE., RICHMOND, CA • WWW.SFEI.ORG Suggested citation: Sedlak, M., Sutton R., Wong A., Lin, Diana. 2018. Per and Polyfluoroalkyl Substances (PFASs) in San Francisco Bay: Synthesis and Strategy. RMP Contribution No. 867. San Francisco Estuary Institute, Richmond CA. 130 pages. FINAL JUNE 2018 Contents Executive Summary ....................................................................................................................................... 1 1.0 Introduction and Overview of PFAS Chemistry, Uses, Concerns and Management ........................ 4 1.1 Objectives of this Report............................................................................................................... 4 1.2 PFASs: Structure and Uses ............................................................................................................ 4 1.2.1 Perfluoroalkyl Substances ..................................................................................................... 5 1.2.2 Polyfluoroalkyl Substances ................................................................................................... 5 1.3 Uses of PFASs ................................................................................................................................ 7 1.4 Growing Concerns: Ubiquitous Contamination, Hot Spots, and Toxicity Studies ........................ 8 1.4.1 Widely Detected Contaminants with Uniquely High Bay Biota Concentrations................... 8 1.4.2 Toxicity .................................................................................................................................. 8 1.5 Fate in the Environment and Degradation Products .................................................................. 10 1.6 Management Actions .................................................................................................................. 11 1.6.1 International ....................................................................................................................... 11 1.6.2 Federal ................................................................................................................................ 12 1.6.3 California ............................................................................................................................. 13 2.0 Summary of PFAS Occurrence and Trends in San Francisco Bay .................................................... 14 2.1 PFASs in San Francisco Bay: Abiotic Environment ...................................................................... 14 2.1.1 Water .................................................................................................................................. 14 2.1.2 Sediment ............................................................................................................................. 17 2.2 PFASs in San Francisco Bay Bivalves ........................................................................................... 21 2.3 PFASs in San Francisco Bay Fish .................................................................................................. 21 2.3.1 Prey Fish .............................................................................................................................. 22 2.3.2 Sport Fish ............................................................................................................................ 25 2.4 PFASs in San Francisco Bay Double-crested Cormorant Eggs ..................................................... 27 2.5 PFASs in San Francisco Bay Harbor Seals .................................................................................... 31 3.0 PFAS Contamination and Potential Risks ........................................................................................ 34 3.1 Risks to Humans: PFAS Levels in Fish Pose Possible Risk for Human Consumption ................... 34 3.2 Risks to Wildlife ........................................................................................................................... 34 3.2.1 PFASs Are Unlikely to Pose Risks to Bivalves ...................................................................... 34 3.2.2 PFASs Are Unlikely to Pose Risks to Fish ............................................................................. 34 3.2.3 PFASs May Pose Risks to Birds ............................................................................................ 35 3.2.4 PFASs May Pose Risks to Harbor Seals ................................................................................ 36 ii FINAL JUNE 2018 3.3 Potential for Risks: Summary ...................................................................................................... 37 4.0 PFAS Pathways and Loads to San Francisco Bay ............................................................................. 38 4.1 Pathways of PFASs to the Bay: Stormwater and Large Tributaries ............................................ 38 4.2 Pathways of PFASs to Bay: Wastewater Effluent ....................................................................... 41 4.3 Other Pathways to the Bay: Groundwater, Spills and Releases, and Air Deposition ................. 43 4.4 Loadings of PFASs to the Bay: Modeling Inputs and Ambient Concentrations .......................... 45 5.0 Past and Future Trends in Contamination ...................................................................................... 49 5.1 Trends of PFASs in Abiotic Media ............................................................................................... 49 5.1.1 Wastewater ......................................................................................................................... 49 5.2 Trends of PFASs in San Francisco Bay Biota ................................................................................ 50 5.2.1 Declining PFOS Concentrations in Cormorant Eggs ............................................................ 50 5.2.2 Declining PFOS Concentrations in Seals .............................................................................. 52 5.3 Anticipated Future Trends .......................................................................................................... 52 5.3.1 Continued Detection of Perfluoroalkyl Carboxylates and Sulfonates ................................ 52 5.3.2 Expanding Number of Unknown Alternatives .................................................................... 54 6.0 CEC Strategy: Classification of PFASs in the Tiered Risk Framework ............................................. 55 6.1 Recommendation for PFOS (maintain as moderate concern) .................................................... 56 6.2 Recommendation for long-chain perfluoroalkyl carboxylates (moderate concern) .................. 56 6.3 Recommendation for other PFASs (possible concern) ............................................................... 57 7.0 PFAS Monitoring and Management Strategy ................................................................................. 58 7.1 Monitoring Strategy .................................................................................................................... 58 References .................................................................................................................................................. 61 iii FINAL JUNE 2018 List of Figures Figure 1 Structures of Several Perfluoroalkyl and Polyfluoroalkyl Substances Figure 2 Concentrations of PFOA in Water Figure 3 Location of Sediment Sites Analyzed for PFASs Figure 4 PFAS Concentrations in Sediment Figure 5 PFOS Concentrations in Prey Fish Figure 6 Location of Sampling Sites for Sport Fish Figure 7 Concentrations of PFOS in Sport Fish Figure 8 Location of Bird and Seal Sampling Sites Figure 9 Concentrations of PFASs in Cormorant Eggs Figure 10 Concentrations of PFASs in Seal Blood Figure 11 Location of Stormwater Sampling Sites for PFASs Figure 12 Trends in Averages of Select PFASs in Effluent Figure 13 Trends of PFOS in Cormorants Eggs Appendix List of Tables Table 1 Half-lives of Select PFASs Table 2a Open Water PFAS Concentrations Table 2b Open Water PFAS Precursors Concentrations Table 3a Bay Sediment PFAS Concentrations Table 3b Bay Sediment PFAS Precursor Concentrations Table 4 Bivalve PFAS Concentrations Table 5 Prey Fish PFAS Concentrations Table 6 PFASs in Sport Fish Table 7 PFASs in Cormorant Eggs Table 8 PFASs in Harbor Seals Table 9a PFASs in Stormwater iv FINAL JUNE 2018 Table 9b PFAS Precursors in Stormwater Table 10a PFASs in Effluent Table 10b PFAS Precursors in Effluent Table 11 Comparison of Model versus Monitored Concentrations for Water in Bay Area Subembayments v FINAL JUNE 2018 Glossary of Acronyms of Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) Chain Subclass Chemicals length Acronym Perfluoroalkyl carboxylic acids (PFCAs) Perfluorobutanoic acid C4 PFBA Perfluoropentanoic acid C5 PFPeA Perfluorohexanoic acid C6 PFHxA Perfluoroheptanoic acid C7 PFHpA Perfluorooctanoic acid* C8 PFOA Perfluorononanoic acid* C9 PFNA Perfluorodecanoic acid* C10 PFDA Perfluorundecanoic acid* C11 PFUnDA Perfluorododecanoic acid* C12 PFDoA Perfluoroalkyl sulfonic acids Perfluorobutane sulfonic (PFSAs) acid C4 PFBS Perfluoropentane sulfonic acid C5 PFPeS Perfluorohexane