Title: Biblio RTF Export
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Dougherty, J.; Kleckner, A.; Sutton, R.; Yee, D.; Gilbreath, A.; Trinh, M. 2024. Water Year 2024 RMP Near-Field Water Sampling and Analysis Plan.  SFEI Contribution No. 1154.
This report details sampling and analysis plans associated with the pilot near-field water sampling for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). The RMP added a pilot effort to the  Status & Trends (S&T) Program to quantify contaminants of emerging concern (CECs) in Bay water in areas near (?near-field? of) expected loading pathways during or shortly after storm events and during the dry season. For the first year of the pilot (Water Year 2022), the near-field design included three targeted, near-field stations and four ambient Bay stations. A fourth near-field station was added in subsequent years. Samples are collected at these stations during or shortly after two storm events, and once in the dry season. The analytes being measured include bisphenols, organophosphate esters (OPEs), PFAS-target, PFAS-TOP, and a suite of stormwater CECs.

Mendez, M.; Kleckner, A.; Sutton, R.; Yee, D.; Wong, A.; Davis, J.; Sigala, M. 2023. 2023 Bay Prey Fish and  Near-field / Margins Sediment Sampling and Analysis Plan.  SFEI Contribution No. 1141. San Francisco Estuary Institute: Richmond, CA.
This is a sampling and analysis plan for the Bay Status and Trends (S&T) Prey Fish and Near-field / Margins Sediment monitoring for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). Bay margins are defined by the RMP as extending from Mean Higher High Water (MHHW) to 1 foot below Mean Lower Low Water (MLLW). These mud flats and adjacent shallow areas of the Bay are productive and highly utilized by biota of interest (humans and wildlife). Near-field stations are located near watershed inputs in the Bay. Prey fish are a key matrix to monitoring the status and impacts of contaminants, especially near margin areas where they have shown strong contamination signals in previous RMP studies. This monitoring design provides a spatially-distributed characterization of contaminant concentrations in fish and sediment found within the margins of Central Bay, South Bay, and Lower South Bay. This study builds on previous S&T efforts to characterize surface sediment contamination across the Bay while piloting routine monitoring of prey fish. Additional samples outside of S&T will be collected for special studies. A subset of samples will be archived for potential future analysis of emerging contaminants or other analyte groups.

Kleckner, A.; Sutton, R.; Yee, D.; Wong, A.; Davis, J.; Salop, P. 2023. 2023 RMP Dry Season Water Cruise Plan.  SFEI Contribution No. 1139. San Francisco Estuary Institute: Richmond, CA.
This report details plans associated with the 2023 Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) water cruise. The RMP water sampling program was redesigned in 2002 to adopt a randomized sampling design at thirty-one stations in place of the twenty-six base program stations sampled previously. In 2007, the number of stations was decreased to twenty-two stations, and it remains as such for 2023. The analytes for 2023 are based on the Status and Trends (S&T) Review process that started in 2020.

Kleckner, A.; Sutton, R.; Yee, D.; Wong, A.; Davis, J.; Salop, P. 2023. 2023 RMP Sediment Cruise  Sampling and Analysis Plan.  SFEI Contribution No. 1138. San Francisco Estuary Institute: Richmond, CA.
This report details plans associated with the Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) deep bay sediment cruise. The RMP, through the Status and Trends monitoring program, conducts routine monitoring of water, sediment and biological tissue. Deep bay stations (water depth lower than 1 foot below MLLW) have been sampled for the Status and Trends sediment program since its inception.  The current monitoring design (reflective of changes made to the Program through the Status and Trends Review process) calls for sampling frequency of deep bay sediment for CECs, PBDEs, and ancillary analytes every five years during the dry season. Every ten years, metals, PAHs, and PCBs will also be sampled. For 2023, sampling operations will entail dry season sample collection at 16 RMP sediment sampling stations for CECs, PBDEs, and ancillary analytes in Central Bay, South Bay, and Lower South Bay.

Lindborg, A. R.; Overdahl, K. E.; Vogler, B.; Lin, D.; Sutton, R.; P. Ferguson, L. 2023. Assessment of Long-Chain Polyethoxylate Surfactants in Wastewater Effluent, Stormwater Runoff, and Ambient Water of San Francisco Bay, CA.  SFEI Contribution No. 1126. American Chemical Society.
Ethoxylated surfactants are ubiquitous organic environmental contaminants that have received continued attention over the past several decades, particularly as manufacturing rates increase worldwide and as toxicity concerns grow regarding alcohol ethoxylates. Presence of these compounds in surface water has been considered primarily the result of contaminated wastewater effluent by ethoxylated surfactant degradates; as a result, monitoring has focused on the small subset of short-chain ethoxylates in wastewater effluent and receiving waters. This study quantified long-chain alcohol and alkylphenol ethoxylated surfactants in San Francisco Bay area stormwater runoff, wastewater effluent, and ambient Bay water to determine concentrations and inform potential pathways of contamination. We employed high-performance liquid chromatography coupled to high-resolution mass spectrometry to quantitate long-chain polyethoxylates, which are rarely monitored in ethoxylated surfactant studies. Similar total ethoxylated surfactant concentrations were observed in stormwater runoff (0.004?4.7 ?g/L) and wastewater effluent (0.003?4.8 ?g/L, outlier of 45 ?g/L). Ambient Bay water contamination (0.0001?0.71 ?g/L) was likely the result of both stormwater and wastewater inputs to San Francisco Bay. These results suggest that a broader focus including long-chain compounds and stormwater pathways may be needed to fully characterize the occurrence and impacts of ethoxylated surfactants in urban surface waters.

B?lan, S. A.; Andrews, D. Q.; Blum, A.; Diamond, M. L.; Fernández, S. Rojello; Harriman, E.; Lindstrom, A. B.; Reade, A.; Richter, L.; Sutton, R.; et al. 2023. Optimizing Chemicals Management in the United States and Canada through the Essential-Use Approach. Environmental Science & Technology 57 (4).
Chemicals have improved the functionality and convenience of industrial and consumer products, but sometimes at the expense of human or ecological health. Existing regulatory systems have proven to be inadequate for assessing and managing the tens of thousands of chemicals in commerce. A different approach is urgently needed to minimize ongoing production, use, and exposures to hazardous chemicals. The premise of the essential-use approach is that chemicals of concern should be used only in cases in which their function in specific products is necessary for health, safety, or the functioning of society and when feasible alternatives are unavailable. To optimize the essential-use approach for broader implementation in the United States and Canada, we recommend that governments and businesses (1) identify chemicals of concern for essentiality assessments based on a broad range of hazard traits, going beyond toxicity; (2) expedite decision-making by avoiding unnecessary assessments and strategically asking up to three questions to determine whether the use of the chemical in the product is essential; (3) apply the essential-use approach as early as possible in the process of developing and assessing chemicals; and (4) engage diverse experts in identifying chemical uses and functions, assessing alternatives, and making essentiality determinations and share such information broadly. If optimized and expanded into regulatory systems in the United States and Canada, other policymaking bodies, and businesses, the essential-use approach can improve chemicals management and shift the market toward safer chemistries that benefit human and ecological health.

Arnold, W. A.; Carigan, C. C.; Cortopassi, G.; Datta, S.; DeWitt, J.; Doherty, A. - C.; Halden, R. U.; Harari, H.; Hartmann, E. M.; Hrubec, T. C.; et al. 2023. Quaternary Ammonium Compounds: A Chemical Class of Emerging Concern. Environmental Science & Technology 57 (20).
Quaternary ammonium compounds (QACs), a large class of chemicals that includes high production volume substances, have been used for decades as antimicrobials, preservatives, and antistatic agents and for other functions in cleaning, disinfecting, personal care products, and durable consumer goods. QAC use has accelerated in response to the COVID-19 pandemic and the banning of 19 antimicrobials from several personal care products by the US Food and Drug Administration in 2016. Studies conducted before and after the onset of the pandemic indicate increased human exposure to QACs. Environmental releases of these chemicals have also increased. Emerging information on adverse environmental and human health impacts of QACs is motivating a reconsideration of the risks and benefits across the life cycle of their production, use, and disposal. This work presents a critical review of the literature and scientific perspective developed by a multidisciplinary, multi-institutional team of authors from academia, governmental, and nonprofit organizations. The review evaluates currently available information on the ecological and human health profile of QACs and identifies multiple areas of potential concern. Adverse ecological effects include acute and chronic toxicity to susceptible aquatic organisms, with concentrations of some QACs approaching levels of concern. Suspected or known adverse health outcomes include dermal and respiratory effects, developmental and reproductive toxicity, disruption of metabolic function such as lipid homeostasis, and impairment of mitochondrial function. QACs? role in antimicrobial resistance has also been demonstrated. In the US regulatory system, how a QAC is managed depends on how it is used, for example in pesticides or personal care products. This can result in the same QACs receiving different degrees of scrutiny depending on the use and the agency regulating it. Further, the US Environmental Protection Agency?s current method of grouping QACs based on structure, first proposed in 1988, is insufficient to address the wide range of QAC chemistries, potential toxicities, and exposure scenarios. Consequently, exposures to common mixtures of QACs and from multiple sources remain largely unassessed. Some restrictions on the use of QACs have been implemented in the US and elsewhere, primarily focused on personal care products. Assessing the risks posed by QACs is hampered by their vast structural diversity and a lack of quantitative data on exposure and toxicity for the majority of these compounds. This review identifies important data gaps and provides research and policy recommendations for preserving the utility of QAC chemistries while also seeking to limit adverse environmental and human health effects.

Moran, K.; Sutton, R. 2023. Tire Wear: Emissions Estimates and Market Insights to Inform Monitoring Design.  Gilbreath, A., Méndez, M., Lin, D., Eds..  SFEI Contribution No. 1109. San Francisco Estuary Institute: Richmond, CA.
Every vehicle on the road sheds tiny particles from its rubber tires into the environment. Tire wear is one of the top sources of microplastic releases to the environment. Tire wear also disperses tire-related chemicals into the environment. SFEI studies supported by the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) and others have found tire wear particles and tire-related chemicals in San Francisco Bay and its small tributaries, which drain the Bay watershed?s local urban areas. The RMP has developed a short-term multi-year plan of potential special studies (?Tires Strategy?) that responds to recent data revealing the magnitude of tire particle and chemical emissions and their potential toxicity to aquatic organisms.
This article is available upon request. Please message rebeccas@sfei.org for the materials.

Lin, D.; Hamilton, C.; Hobbs, J.; Miller, E.; Sutton, R. 2023. Triclosan and Methyl Triclosan in Prey Fish in a Wastewater-influenced Estuary. Environmental Toxicology and Chemistry . SFEI Contribution No. 1112.
While the antimicrobial ingredient triclosan has been widely monitored in the environment, much less is known about the occurrence and toxicity of its major transformation product, methyl triclosan. An improved method was developed and validated to effectively extract and quantify both contaminants in fish tissue and was used to characterize concentrations in small prey fish in areas of San Francisco Bay where exposure to triclosan via municipal wastewater discharges was expected to be highest. Concentrations of triclosan (0.44?57 ng/g ww, median 1.9 ng/g ww) and methyl triclosan (1.1?200 ng/g ww, median 36 ng/g ww) in fish tissue decreased linearly with concentrations of nitrate in site water, used as indicators of wastewater influence. The total concentrations of triclosan and methyl triclosan measured in prey fish were below available toxicity thresholds for triclosan, but there are few ecotoxicological studies to evaluate impacts of methyl triclosan. Methyl triclosan represented up to 96% of the total concentrations observed. These results emphasize the importance of monitoring contaminant transformation products, which can be present at higher levels than the parent compound.

Kleckner, A.; Sutton, R.; Yee, D.; Gilbreath, A.; Trinh, M. 2023. Water Year 2023 RMP Near-Field Water Sampling and Analysis Plan.  SFEI Contribution No. 1142. San Francisco Estuary Institute: Richmond, CA.
This report details plans associated with the pilot near-field water sampling for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). The RMP recently reviewed the Status & Trends (S&T) Program and added a pilot effort to quantify contaminants of emerging concern (CECs) in Bay water in areas near (?near-field? of) expected loading pathways during or shortly after storm events and during the dry season. For the first year of the pilot (Water Year 2022), the near-field design included three targeted, near-field stations and four ambient Bay stations. Subsequent years added a fourth near-field station. Samples will be collected at these stations during or shortly after two storm events, and once in the dry season. The analytes that are being measured include bisphenols, organophosphate esters (OPEs), PFAS, and a suite of stormwater CECs.

Davis, J.; Foley, M.; Askevold, R. A.; Sutton, R.; Senn, D.; Plane, E. 2022. 2022 Pulse of the Bay.  SFEI Contribution No. 1095. San Francisco Estuary Institute: Richmond, California.
The theme of the 2022 Pulse is "50 Years After the Clean Water Act." Nine different individuals or groups have contributed perspectives on progress to date and challenges ahead. This Pulse also includes summaries, from a historical perspective, on the major water quality parameters of concern in the Bay.   

Mendez, M.; Miller, E.; Liu, J.; Chen, D.; Sutton, R. 2022. Bisphenols in San Francisco Bay: Wastewater, Stormwater, and Margin Sediment Monitoring.  SFEI Contribution No. 1093. San Francisco Estuary Institute: Richmond, CA.
Bisphenols are a class of synthetic, mobile, endocrine-disrupting chemicals. Bisphenol A (BPA), the most well-studied bisphenol, is produced and used in vast quantities worldwide?especially in polycarbonate plastics and as a polymer additive. Recently, some manufacturers have begun using alternative bisphenol compounds, such as bisphenol F (BPF) and bisphenol S (BPS). These uses of bisphenols have led to widespread bisphenol detections in the environment and wildlife. The present study examined wastewater effluent in the San Francisco Bay Area and San Francisco Bay sediment samples for 17 bisphenols. The effluent samples were compared to available stormwater runoff data to better understand bisphenol transport, fate, and potential risks to wildlife.

Sutton, R.; Lin, D. 2022. CECs in California?s Ambient Aquatic Ecosystems: Occurrence and Risk Screening of Key Classes.  Miller, E., Wong, A., Mendez, M., Eds.. ASC Contribution.  SFEI Contribution No. 1066. Aquatic Science Center: Richmond, CA.

Shimabuku, I.; Chen, D.; Wu, Y.; Miller, E.; Sun, J.; Sutton, R. 2022. Occurrence and risk assessment of organophosphate esters and bisphenols in San Francisco Bay, California, USA. Science of the Total Environment 813 . SFEI Contribution No. 982.
Organophosphate esters (OPEs) and bisphenols are two classes of industrial chemicals that are ubiquitously detected in environmental matrices due to high global production and widespread use, particularly in the manufacture of plastic products. In 2017, water samples collected throughout the highly urbanized San Francisco Bay were analyzed for 22 OPEs and 16 bisphenols using liquid chromatography-electrospray ionization-Q Trap-mass spectrometry. Fifteen of the 22 OPEs were detected, with highest median concentrations in the order TCPP (42 ng/L) > TPhP (9.5 ng/L) > TBOEP (7.6 ng/L) > TnBP (7.5 ng/L) > TEP (6.7 ng/L) > TDCIPP (6.2 ng/L). In contrast, only two of 16 bisphenols, BPA and BPS, were quantified, with concentrations ranging from <0.7?35 ng/L and <1?120 ng/L, respectively. BPA and a few OPEs (EHDPP and TEHP) were primarily present in the particulate phase, while BPS and all other observed OPEs were predominantly found in the dissolved phase. Pairwise correlation analysis revealed several strong, positive correlations among OPEs, and few weak, negative correlations between OPEs and BPA, suggesting differences between the two classes with respect to their sources, pathways, and/or fate in the environment. Concentrations of OPEs and bisphenols observed in this study were generally consistent with reported concentrations in other estuarine and marine settings globally. TDCIPP exceeded existing predicted no-effect concentrations (PNECs) at some sites, and six other compounds (TCrP, IDDPP, EHDPP, TPhP, TBOEP, and BPA) were observed at levels approaching individual compound PNECs (not considering mixture effects), indicating potential risks to Bay biota. These results emphasize the need to control releases of these contaminants in order to protect the ecosystem. Periodic monitoring can be used to maintain vigilance in the face of potential regrettable substitutions.

Mendez, M.; Trinh, M.; Miller, E.; Lin, D.; Sutton, R. 2022. PFAS in San Francisco Bay Water.  SFEI Contribution No. 1094. San Francisco Estuary Institute: Richmond, CA.
Per- and polyfluoroalkyl substances (PFAS), a family of thousands of synthetic, fluorine-rich compounds commonly referred to as ?forever chemicals,? are known for their thermal stability, non-reactivity, and surfactant properties. These unique compounds have widespread uses across consumer, commercial, and industrial products, resulting in widespread occurrence in the environment and wildlife across the globe. This study analyzed ambient surface water in San Francisco Bay for 40 PFAS to discern the occurrence, fate, and potential risks to ecological and human health.
Eleven of 40 PFAS were detected in ambient surface water collected in 2021 from 22 sites in the Bay. Seven PFAS (PFPeA, PFHxA, PFHpA, PFOA, PFBS, PFHxS, and PFOS), were found in at least 50% of samples. PFHxA and PFOA were the most frequently detected analytes (detection frequencies of 86% and 77%, respectively). PFPeA and PFHxA were generally found at the highest concentrations across sites, with median and maximum concentrations of 1.6 and 4.8 ng/L and 1.5 and 5.7 ng/L, respectively. Pairwise Spearman's correlations revealed strong positive correlations  (p <0.001; r > 0.77) among the seven PFAS detected in at least 50% of sites, suggesting significant similarities between their sources, pathways, and/or fate in the environment. PFBA, PFNA, PFDA, and 6:2 FTS were found at a limited number of sites in the Bay. 6:2 FTS was found at a single site at 14 ng/L, the highest concentration of any individual PFAS in the Bay. The sums of detected PFAS for all sites had median and maximum concentrations of 10 and 29 ng/L, respectively.

Wang, M.; Kinyua, J.; Jiang, T.; Sedlak, M.; McKee, L. J.  .; Fadness, R.; Sutton, R.; Park, J. - S. 2022. Suspect Screening and Chemical Profile Analysis of Storm-Water Runoff Following 2017 Wildfires in Northern California. Environmental Toxicology and Chemistry . SFEI Contribution No. 1089.
The combustion of structures and household materials as well as firefighting during wildfires lead to releases of potentially hazardous chemicals directly into the landscape. Subsequent storm-water runoff events can transport wildfire-related contaminants to downstream receiving waters, where they may pose water quality concerns. To evaluate the environmental hazards of northern California fires on the types of contaminants in storm water discharging to San Francisco Bay and the coastal marine environment, we analyzed storm water collected after the northern California wildfires (October 2017) using a nontargeted analytical (NTA) approach. Liquid chromatography quadrupole time-of-flight mass spectrometric analysis was completed on storm-water samples (n?=?20) collected from Napa County (impacted by the Atlas and Nuns fires), the city of Santa Rosa, and Sonoma County (Nuns and Tubbs fires) during storm events that occurred in November 2017 and January 2018. The NTA approach enabled us to establish profiles of contaminants based on peak intensities and chemical categories found in the storm-water samples and to prioritize significant chemicals within these profiles possibly attributed to the wildfire. The results demonstrated the presence of a wide range of contaminants in the storm water, including surfactants, per- and polyfluoroalkyl substances, and chemicals from consumer and personal care products. Homologs of polyethylene glycol were found to be the major contributor to the contaminants, followed by other widely used surfactants. Nonylphenol ethoxylates, typically used as surfactants, were detected and were much higher in samples collected after Storm Event 1 relative to Storm Event 2. The present study provides a comprehensive approach for examining wildfire-impacted storm-water contamination of related contaminants, of which we found many with potential ecological risk. Environ Toxicol Chem 2022;00:1?14. © 2022 SETAC

Foley, M.; Sutton, R.; Yee, D.; Salop, P. 2021. 2021 RMP Water Cruise Plan.  SFEI Contribution No. 1050. San Francisco Estuary Institute: Richmond, California.
This report details plans associated with the annual Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) water cruise. The RMP water sampling program was redesigned in 2002 to adopt a randomized sampling design at thirty-one sites in place of the twenty-six base program stations sampled previously. In 2007, the number of sites was decreased to twenty-two stations, and it remains as such for 2021. The analytes for 2021 have been modified based on the Status and Trends (S&T) Review process that started in 2020. The analytes that are being removed from the program include selenium and methylmercury (dissolved and particulate), while bisphenols and organophosphate esters (OPEs) have been added to S&T monitoring. 

Overdahl, K. E.; Sutton, R.; Sun, J.; DeStefano, N. J.; Getzinger, G. J.; P. Ferguson, L. 2021. Assessment of emerging polar organic pollutants linked to contaminant pathways within an urban estuary using non-targeted analysis.  SFEI Contribution No. 1107. Environmental Sciences: Processes and Impacts.
A comprehensive, non-targeted analysis of polar organic pollutants using high resolution/accurate mass (HR/AM) mass spectrometry approaches has been applied to water samples from San Francisco (SF) Bay, a major urban estuary on the western coast of the United States, to assess occurrence of emerging contaminants and inform future monitoring and management activities. Polar Organic Chemical Integrative Samplers (POCIS) were deployed selectively to evaluate the influence of three contaminant pathways: urban stormwater runoff (San Leandro Bay), wastewater effluent (Coyote Creek, Lower South Bay), and agricultural runoff (Napa River). Grab samples were collected before and after deployment of the passive samplers to provide a quantitative snapshot of contaminants for comparison. Composite samples of wastewater effluent (24 hours) were also collected from several wastewater dischargers. Samples were analyzed using liquid-chromatography coupled to high resolution mass spectrometry. Resulting data were analyzed using a customized workflow designed for high-fidelity detection, prioritization, identification, and semi-quantitation of detected molecular features. Approximately 6350 compounds were detected in the combined data set, with 424 of those compounds tentatively identified through high quality spectral library match scores. Compounds identified included ethoxylated surfactants, pesticide and pharmaceutical transformation products, polymer additives, and rubber vulcanization agents. Compounds identified in samples were reflective of the apparent sources and pathways of organic pollutant inputs, with stormwater-influenced samples dominated by additive chemicals likely derived from plastics and vehicle tires, as well as ethoxylated surfactants.

Buzby, N.; Davis, J. A.; Sutton, R.; Miller, E.; Yee, D.; Wong, A.; Sigala, M.; Bonnema, A.; Heim, W.; Grace, R. 2021. Contaminant Concentrations in Sport Fish from San Francisco Bay: 2019.  SFEI Contribution No. 1036. San Francisco Estuary Institute: Richmond, CA.

Chang, D.; Richardot, W.; Miller, E.; Dodder, N.; Sedlak, M.; Hoh, E.; Sutton, R. 2021. Framework for nontargeted investigation of contaminants released by wildfires into stormwater runoff: Case study in the northern San Francisco Bay area. Integrated Environmental Assessment and Management . SFEI Contribution No. 1044.
Wildfires can be extremely destructive to communities and ecosystems. However, the full scope of the ecological damage is often hard to assess, in part due to limited information on the types of chemicals introduced to affected landscapes and waterways. The objective of this study was to establish a sampling, analytical, and interpretive framework to effectively identify and monitor contaminants of emerging concern in environmental water samples impacted by wildfire runoff. A nontargeted analysis consisting of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC?×?GC/TOF-MS) was conducted on stormwater samples from watersheds in the City of Santa Rosa and Sonoma and Napa Counties, USA, after the three most destructive fires during the October 2017 Northern California firestorm. Chemicals potentially related to wildfires were selected from the thousands of chromatographic features detected through a screening method that compared samples from fire-impacted sites versus unburned reference sites. This screening led to high confidence identifications of 76 potentially fire-related compounds. Authentic standards were available for 48 of these analytes, and 46 were confirmed by matching mass spectra and GC?×?GC retention times. Of these 46 compounds, 37 had known commercial and industrial uses as intermediates or ingredients in plastics, personal care products, pesticides, and as food additives. Nine compounds had no known uses or sources and may be oxidation products resulting from burning of natural or anthropogenic materials. Preliminary examination of potential toxicity associated with the 46 compounds, conducted via online databases and literature review, indicated limited data availability. Regional comparison suggested that more structural damage may yield a greater number of unique, potentially wildfire-related compounds. We recommend further study of post-wildfire runoff using the framework described here, which includes hypothesis-driven site selection and nontargeted analysis, to uncover potentially significant stormwater contaminants not routinely monitored after wildfires and inform risk assessment. 

Zhu, X.; Munno, K.; Grbic, J.; Werbowski, L. M.; Bikker, J.; Ho, A.; Guo, E.; Sedlak, M.; Sutton, R.; Box, C.; et al. 2021. Holistic Assessment of Microplastics and Other Anthropogenic Microdebris in an Urban Bay Sheds Light on Their Sources and Fate. Environmental Science and Technology Water . SFEI Contribution No. 1060.

The physical and chemical properties of microplastics and their environmental distributions may provide clues about their sources and inform their fate. We demonstrate the value of extensive monitoring of microplastics in an urban bay, San Francisco Bay. Surface water, fish, sediment, stormwater runoff, and treated wastewater were sampled across the bay and adjacent national marine sanctuaries (NMS). We found microplastics and other anthropogenic microdebris (?microdebris?) in all sample types. Concentrations were higher in the bay than in the NMS, and within the bay, concentrations were higher during the wet season than during the dry season. The fate of microdebris varied depending on their morphologies and densities: fibers were dominant in fish, black rubbery fragments were common in sediment, as were fibers, while buoyant fragments and fibers were widely observed in surface waters. Notably, we found large amounts of black rubbery fragments, an emerging contaminant, in stormwater. Moreover, stormwater was a significant pathway of microdebris, with concentrations roughly 140 times greater than those found in wastewater, which was dominated by fibers. Overall, we demonstrate the value of multimatrix regional monitoring to evaluate the sources and fate of microplastics, which can inform effective mitigation for other urban bays around the world.<br /><br /> 

Davis, J.; Foley, M.; Askevold, R.; Chelsky, A.; Dusterhoff, S.; Gilbreath, A.; Lin, D.; Yee, D.; Senn, D.; Sutton, R. 2021. RMP Update 2021.  SFEI Contribution No. 1057.
The overarching goal of the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) is to answer the highest priority scientific questions faced by managers of Bay water quality. The RMP is an innovative collaboration between the San Francisco Bay Regional Water Quality Control Board, the regulated discharger community, the San Francisco Estuary Institute, and many other scientists and interested parties. The purpose of this document is to provide a concise overview of recent RMP activities and findings, and a look ahead to significant products anticipated in the next two years. The report includes a description of the management context that guides the Program; a brief summary of some of the most noteworthy findings of this multifaceted Program; and a summary of progress to date and future plans for addressing priority water quality topics.

Mendez, M.; Lin, D.; Sutton, R. 2021. Study of Per- and Polyfluoroalkyl Substances in Bay Area POTWs: Phase 1, Sampling and Analysis Plan.  SFEI Contribution No. 1020. San Francisco Estuary Institute: Richmond, CA.

Miller, E.; Sedlak, M.; Sutton, R.; Chang, D.; Dodder, N.; Hoh, E. 2021. Summary for Managers: Non-targeted Analysis of Stormwater Runoff following the 2017 Northern San Francisco Bay Area Wildfires.  SFEI Contribution No. 1045. San Francisco Estuary Institute: Richmond, CA.
Urban-wildland interfaces in the western US are increasingly threatened by the growing number and intensity of wildfires, potentially changing the type of contaminants released into the landscape as more urban structures are burned. In October 2017, the Tubbs, Nuns, and Atlas wildfires devastated communities in Northern California (Figure 1), burning over 8,500 buildings and 210,000 acres of land in the span of 24 days (California Department of Forestry and Fire Protection 2017). Together, these wildfires were the most destructive and costliest fires in the history of California at that time (California Department of Forestry and Fire Protection 2019). 
Post-wildfire monitoring efforts in impacted watersheds typically focus on a few well-established water quality and chemistry concerns (McKee et al. 2018). Few studies go beyond these limited targeted analyses and attempt to identify the multitude of other fire-related compounds that are released from or form as the result of combustion of residential, commercial, and industrial structures in urban-wildland interfaces. Some of these unidentified compounds may be toxic to aquatic ecosystems or human health, and may pose risks to wildlife or in water bodies that act as drinking water supplies to nearby communities.  

Moran, K.; Miller, E.; Mendez, M.; Moore, S.; Gilbreath, A.; Sutton, R.; Lin, D. 2021. A Synthesis of Microplastic Sources and Pathways to Urban Runoff.  SFEI Contribution No. 1049. San Francisco Estuary Institute: Richmond, CA.
California Senate Bill 1263 (2018) tasks the Ocean Protection Council (OPC) with leading statewide efforts to address microplastic pollution, and requires the OPC to adopt and implement a Statewide Microplastics Strategy related to microplastic materials that pose an emerging concern for ocean health. Key questions remain about the sources and pathways of microplastics, particularly to urban runoff, to inform an effective statewide microplastics management strategy. The OPC funded this work to inform these microplastics efforts. The purpose of this project was to build conceptual models that synthesize and integrate our current understanding of microplastic sources and pathways to urban runoff in order to provide future research priorities that will inform how best to mitigate microplastic pollution. Specifically, we developed conceptual models for cigarette butts and associated cellulose acetate fibers (Section 2), fibers other than cellulose acetate (Section 3), single-use plastic foodware and related microplastics (Section 4), and tire particles (Section 5), which were prioritized based on findings from the recent urban stormwater monitoring of microplastics in the San Francisco Bay region. Conceptual models specific to each of these particle types are valuable tools to refine source identification and elucidate potential source-specific data gaps and management options.

Werbowski, L. M.; Gilbreath, A.; Munno, K.; Zhu, X.; Grbic, J.; Wu, T.; Sutton, R.; Sedlak, M.; Deshpande, A. D.; Rochman, C. M. 2021. Urban Stormwater Runoff: A Major Pathway for Anthropogenic Particles, Black Rubbery Fragments, and Other Types of Microplastics to Urban Receiving Waters. Environmental Science and Technology Water . SFEI Contribution No. 1040.
Stormwater runoff has been suggested to be a significant pathway of microplastics to aquatic habitats; yet, few studies have quantified microplastics in stormwater. Here, we quantify and characterize urban stormwater runoff from 12 watersheds surrounding San Francisco Bay for anthropogenic debris, including microplastics. Depth-integrated samples were collected during wet weather events. All stormwater runoff contained anthropogenic microparticles, including microplastics, with concentrations ranging from 1.1 to 24.6 particles/L. These concentrations are much higher than those in wastewater treatment plant effluent, suggesting urban stormwater runoff is a major source of anthropogenic debris, including microplastics, to aquatic habitats. Fibers and black rubbery fragments (potentially tire and road wear particles) were the most frequently occurring morphologies, comprising ?85% of all particles across all samples. This suggests that mitigation strategies for stormwater should be prioritized. As a case study, we sampled stormwater from the inlet and outlet of a rain garden during three storm events to measure how effectively rain gardens capture microplastics and prevent it from contaminating aquatic ecosystems. We found that the rain garden successfully removed 96% of anthropogenic debris on average and 100% of black rubbery fragments, suggesting rain gardens should be further explored as a mitigation strategy for microplastic pollution.

Miller, E.; Mendez, M.; Shimabuku, I.; Buzby, N.; Sutton, R. 2020. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations 2020 Update.  SFEI Contribution No. 1007. San Francisco Estuary Institute: Richmond, CA.
This 2020 CEC Strategy Update is a brief summary document that describes the addition of recently monitored CECs to the tiered risk-based framework. Reviews of findings relevant to San Francisco Bay are provided, as is a discussion of the role of environmental persistence in classifying CECs within the framework. The Strategy is a living document that guides RMP special studies on CECs, assuring continued focus on the issues of highest priority to protecting the health of the Bay. A key focus of the Strategy is a tiered risk-based framework that guides future monitoring proposals. The Strategy also features a multi-year plan indicating potential future research priorities.

Heberger, M.; Sutton, R.; Buzby, N.; Sun, J.; Lin, D.; Mendez, M.; Hladik, M.; Orlando, J.; Sanders, C.; Furlong, E. 2020. Current-Use Pesticides, Fragrance Ingredients, and Other Emerging Contaminants in San Francisco Bay Margin Sediment and Water.  SFEI Contribution No. 934. San Francisco Estuary Institute: Richmond, CA.
The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) has recently focused attention on better characterization of contaminants in nearshore ?margin? areas of San Francisco Bay. The margins of the Lower South Bay are mudflats and shallow regions that receive direct discharges of stormwater and wastewater; as a result, they may have higher levels of urban contaminants than the open Bay. In the summer of 2017, the RMP collected samples of margin<br />sediment in the South and Lower South Bay for analysis of legacy contaminants. The study described here leveraged that sampling effort by adding monitoring of sediment and water for two additional sets of emerging contaminants: 1) current-use pesticides; and 2) fragrance ingredients including the polycyclic musk galaxolide, as well as a range of other commonly detected emerging contaminants linked to toxicity concerns such as endocrine disruption.

Shimabuku, I.; Chen, D.; Wu, Y.; Sun, J.; Sutton, R. 2020. Flame retardants and plastic additives in San Francisco Bay: Targeted monitoring of organophosphate esters and bisphenols.  SFEI Contribution No. 925. San Francisco Estuary Institute: Richmond, CA.

Hung, C.; Klasios, N.; Zhu, X.; Sedlak, M.; Sutton, R. 2020. Methods Matter: Methods for Sampling Microplastic and Other Anthropogenic Particles and Their Implications for Monitoring and Ecological Risk Assessment. Integrated Environmental Assessment and Management 16 (6) . SFEI Contribution No. 1014.
To inform mitigation strategies and understand how microplastics affect wildlife, research is focused on understanding the sources, pathways, and occurrence of microplastics in the environment and in wildlife. Microplastics research entails counting and characterizing microplastics in nature, which is a labor?intensive process, particularly given the range of particle sizes and morphologies present within this diverse class of contaminants. Thus, it is crucial to determine appropriate sampling methods that best capture the types and quantities of microplastics relevant to inform the questions and objectives at hand. It is also critical to follow protocols with strict quality assurance and quality control (QA/QC) measures so that results reflect accurate estimates of microplastic contamination. Here, we assess different sampling procedures and QA/QC strategies to inform best practices for future environmental monitoring and assessments of exposure. We compare microplastic abundance and characteristics in surface?water samples collected using different methods (i.e., manta and bulk water) at the same sites, as well as duplicate samples for each method taken at the same site and approximate time. Samples were collected from 9 sampling sites within San Francisco Bay, California, USA, using 3 different sampling methods: 1) manta trawl (manta), 2) 1?L grab (grab), and 3) 10?L bulk water filtered in situ (pump). Bulk water sampling methods (both grab and pump) captured more microplastics within the smaller size range (<335 ?m), most of which were fibers. Manta samples captured a greater diversity of morphologies but underestimated smaller?sized particles. Inspection of pump samples revealed high numbers of particles from procedural contamination, stressing the need for robust QA/QC, including sampling and analyzing laboratory blanks, field blanks, and duplicates. Choosing the appropriate sampling method, combined with rigorous, standardized QA/QC practices, is essential for the future of microplastics research in marine and freshwater ecosystems.

Miller, E.; Klasios, N.; Lin, D.; Sedlak, M.; Sutton, R.; Rochman, C. 2020. Microparticles, Microplastics, and PAHs in Bivalves in San Francisco Bay.  SFEI Contribution No. 976. San Francisco Estuary Institute: Richmond, CA.
California mussels (Mytilus californianus and hybrid Mytilus galloprovincialis / Mytilus trossulus) and Asian clams (Corbicula fluminea) were collected at multiple sites in San Francisco Bay. Mussels from a reference area with minimal urban influence were also deployed in cages for 90 days at multiple sites within the Bay prior to collection.Mussels from the reference time zero site, Bodega Head, had some of the lowest microparticle levels found in this study, along with resident clams from the San Joaquin and Sacramento Rivers and mussels transplanted to Pinole Point. The highest concentrations of microparticles were in mussels transplanted to Redwood Creek and Coyote Creek. The results of this study and current literature indicate that bivalves may not be good status and trends indicators of microplastic concentrations in the Bay unless the interest is in human health exposure via contaminated bivalve consumption.

Soberón, F. Sánchez; Sutton, R.; Sedlak, M.; Yee, D.; Schuhmacher, M.; Park, J. - S. 2020. Multi-box mass balance model of PFOA and PFOS in different regions of San Francisco Bay. Chemosphere 252 . SFEI Contribution No. 986.
We present a model to predict the long-term distribution and concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in estuaries comprising multiple intercommunicated sub-embayments. To that end, a mass balance model including rate constants and time-varying water inputs was designed to calculate levels of these compounds in water and sediment for every sub-embayment. Subsequently, outflows and tidal water exchanges were used to interconnect the different regions of the estuary. To calculate plausible risks to population, outputs of the model were used as inputs in a previously designed model to simulate concentrations of PFOA and PFOS in a sport fish species (Cymatogaster aggregata). The performance of the model was evaluated by applying it to the specific case of San Francisco Bay, (California, USA), using 2009 sediment and water sampled concentrations of PFOA and PFOS in North, Central and South regions. Concentrations of these compounds in the Bay displayed exponential decreasing trends, but with different shapes depending on region, compound, and compartment assessed. Nearly stable PFOA concentrations were reached after 50 years, while PFOS needed close to 500 years to stabilize in sediment and fish. Afterwards, concentrations stabilize between 4 and 23 pg/g in sediment, between 0.02 and 44 pg/L in water, and between 7 and 104 pg/g wet weight in fish, depending on compound and region. South Bay had the greatest final concentrations of pollutants, regardless of compartment. Fish consumption is safe for most scenarios, but due to model uncertainty, limitations in monthly intake could be established for North and South Bay catches.

Buzby, N.; Lin, D.; Sutton, R. 2020. Neonicotinoids and Their Degradates in San Francisco Bay Water.  SFEI Contribution No. 1002. San Francisco Estuary Institute: Richmond, CA.
In the summer of 2017, open Bay water samples were collected during the RMP Status and Trends Water Cruise. Samples were analyzed for 19 neonicotinoids and metabolites. The only neonicotinoid detected was imidacloprid, an active ingredient used in both urban and agricultural applications. Imidacloprid was detected at a single site above the method detection limits (2.2-2.6 ng/L) in Lower South Bay at a level of 4.2 ng/L. This value is within the range of concentrations found in a separate RMP study in water samples collected from the South and Lower South Bay margins in 2017. Imidacloprid was detected at 3 of 12 of the margin sites at levels between 3.9 and 11 ng/L; no other neonicotinoids were detected. Of note, these RMP studies appear to represent the first evaluation of ambient neonicotinoid concentrations in an estuarine environment in the nation.

Sun, J.; Sutton, R.; Ferguson, L.; Overdahl, K. 2020. New San Francisco Bay Contaminants Emerge.  SFEI Contribution No. 931. San Francisco Estuary Institute: Richmond, CA.
In 2016, the RMP launched a novel investigation to detect new or unexpected contaminants in Bay waters, as well as treated sewage (or wastewater) discharged to the Bay. This study used non-targeted analysis, a powerful tool that provides a broad, open-ended view of thousands of synthetic and naturally-derived chemicals simultaneously. We identified hundreds of contaminants, and the results have opened our eyes to urban stormwater runoff as an important pathway for emerging contaminants to enter the Bay.

Miller, E.; Sedlak, M.; Lin, D.; Box, C.; Holleman, C.; Rochman, C. M.; Sutton, R. 2020. Recommended Best Practices for Collecting, Analyzing, and Reporting Microplastics in Environmental Media: Lessons Learned from Comprehensive Monitoring of San Francisco Bay. Journal of Hazardous Materials . SFEI Contribution No. 1023.
Microplastics are ubiquitous and persistent contaminants in the ocean and a pervasive and preventable threat to the health of marine ecosystems. Microplastics come in a wide variety of shapes, sizes, and plastic types, each with unique physical and chemical properties and toxicological impacts. Understanding the magnitude of the microplastic problem and determining the highest priorities for mitigation require accurate measures of microplastic occurrence in the environment and identification of likely sources. The field of microplastic pollution is in its infancy, and there are not yet widely accepted standards for sample collection, laboratory analyses, quality assurance/quality control (QA/QC), or reporting of microplastics in environmental samples. Based on a comprehensive assessment of microplastics in San Francisco Bay water, sediment, fish, bivalves, stormwater, and wastewater effluent, we developed recommended best practices for collecting, analyzing, and reporting microplastics in environmental media. We recommend factors to consider in microplastic study design, particularly in regard to site selection and sampling methods. We also highlight the need for standard QA/QC practices such as collection of field and laboratory blanks, use of methods beyond microscopy to identify particle composition, and standardized reporting practices, including suggested vocabulary for particle classification.

Davis, J.; Foley, M.; Askevold, R.; Buzby, N.; Chelsky, A.; Dusterhoff, S.; Gilbreath, A.; Lin, D.; Miller, E.; Senn, D.; et al. 2020. RMP Update 2020.  SFEI Contribution No. 1008.
The overarching goal of the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) is to answer the highest priority scientific questions faced by managers of Bay water quality. The RMP is an innovative collaboration between the San Francisco Bay Regional Water Quality Control Board, the regulated discharger community, the San Francisco Estuary Institute, and many other scientists and interested parties. The purpose of this document is to provide a concise overview of recent RMP activities and findings, and a look ahead to significant products anticipated in the next two years. The report includes a description of the management context that guides the Program; a brief summary of some of the most noteworthy findings of this multifaceted Program; and a summary of progress to date and future plans for addressing priority water quality topics.

Rochman, C. M.; Munno, K.; Box, C.; Cummins, A.; Zhu, X.; Sutton, R. 2020. Think Global, Act Local: Local Knowledge Is Critical to Inform Positive Change When It Comes to Microplastics. Environmental Science & Technology . SFEI Contribution No. 1024.
Microplastic contamination in the marine environment is a global issue. Across the world, policies at the national and international level are needed to facilitate the scale of change needed to tackle this significant problem. However, sources and patterns of plastic contamination vary around the world, and the most pressing actions differ from one location to another. Therefore, local policies are a critical part of the solution; recognizing local sources will enable mitigations with measurable impacts. Here, we highlight how investigating the contamination comprehensively in one location can inform relevant mitigation strategies that can be transferred globally. We examine the San Francisco Bay in California, USA?the largest estuary on the West Coast of the Americas, and home to over 7 million people. The local contamination of microplastics in surface water, sediments, and fish from this urban bay is reportedly higher than many places studied to date.(1) This example demonstrates the value of local monitoring in identifying sources, informing local mitigation strategies and developing an array of solutions to stem the multifaceted tide of plastic pollution entering our global oceans.

Sutton, R.; Chen, D.; Sun, J.; Greig, D. J.; Wu, Y. 2019. Characterization of brominated, chlorinated, and phosphate flame retardants in San Francisco Bay, an urban estuary. Science of the Total Environment 652, 212-223 . SFEI Contribution No. 859.
Flame retardant chemical additives are incorporated into consumer goods to meet flammability standards, and many have been detected in environmental matrices. A uniquely wide-ranging characterization of flame retardants was conducted, including polybrominated diphenyl ethers (PBDEs) and 52 additional brominated, chlorinated, or phosphate analytes, in water, sediment, bivalves, and harbor seal blubber of San Francisco Bay, a highly urbanized estuary once considered a hot spot for PBDE contamination. Among brominated flame retardants, PBDEs remained the dominant contaminants in all matrices, though declines have been observed over the last decade following their phase-out. Hexabromocyclododecane (HBCD) and other hydrophobic, brominated flame retardants were commonly detected at lower levels than PBDEs in sediment and tissue matrices. Dechlorane Plus (DP) and related chlorinated compounds were also detected at lower levels or not at all across all matrices. In contrast, phosphate flame retardants were widely detected in Bay water samples, with highest median concentrations in the order TCPP?>?TPhP?>?TBEP?>?TDCPP?>?TCEP. Concentrations in Bay water were often higher than in other estuarine and marine environments. Phosphate flame retardants were also widely detected in sediment, in the order TEHP?>?TCrP?>?TPhP?>?TDCPP?>?TBEP. Several were present in bivalves, with levels of TDCPP comparable to PBDEs. Only four phosphate flame retardants were detected in harbor seal blubber: TCPP, TDCPP, TCEP, and TPhP. Periodic, multi-matrix screening is recommended to track contaminant trends impacted by changes to flammability standards and manufacturing practices, with a particular focus on contaminants like TDCPP and TPhP that were found at levels comparable to thresholds for aquatic toxicity.

Sedlak, M.; Sutton, R.; Miller, L.; Lin, D. 2019. Microplastic Strategy Update.  SFEI Contribution No. 951. San Francisco Estuary Institute: Richmond, CA.
Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) convened a Microplastic Workgroup (MPWG) in 2016 to discuss the issue, identify management information needs and management questions (MQs), and prioritize studies to provide information to answer these management questions. The MPWG meets annually to review on-going microplastic projects and to conduct strategic long-term planning in response to new information in this rapidly evolving field.
<br />In this nascent field with new findings published almost daily, the Strategy is designed to be a living document that is updated periodically. This Strategy Update includes a short summary of recent findings from the San Francisco Bay Microplastics Project - a major monitoring effort in the Bay - and an updated multi-year plan based on the newly acquired knowledge and current management needs.

Sutton, R.; Xie, Y.; Moran, K. D.; Teerlink, J. 2019. Occurrence and Sources of Pesticides to Urban Wastewater and the Environment. In Pesticides in Surface Water: Monitoring, Modeling, Risk Assessment, and Management. Pesticides in Surface Water: Monitoring, Modeling, Risk Assessment, and Management. American Chemical Society: Washington, DC. pp 63-88.
Municipal wastewater has not been extensively examined as a pathway by which pesticides contaminate surface water, particularly relative to the well-recognized pathways of agricultural and urban runoff. A state-of-the-science review of the occurrence and fate of current-use pesticides in wastewater, both before and after treatment, indicates this pathway is significant and should not be overlooked. A comprehensive conceptual model is presented to establish all relevant pesticide-use patterns with the potential for both direct and indirect down-the-drain transport. Review of available studies from the United States indicates 42 pesticides in current use. While pesticides and pesticide degradates have been identified in wastewater, many more have never been examined in this matrix. Conventional wastewater treatment technologies are generally ineffective at removing pesticides from wastewater, with high removal efficiency only observed in the case of highly hydrophobic compounds, such as pyrethroids. Aquatic life reference values can be exceeded in undiluted effluents. For example, seven compounds, including three pyrethroids, carbaryl, fipronil and its sulfone degradate, and imidacloprid, were detected in treated wastewater effluent at levels exceeding U.S. Environmental Protection Agency (US EPA) aquatic life benchmarks for chronic exposure to invertebrates. Pesticides passing through wastewater treatment plants (WWTPs) merit prioritization for additional study to identify sources and appropriate pollution-prevention strategies. Two case studies, diazinon and chlorpyrifos in household pesticide products, and fipronil and imidacloprid in pet flea control products, highlight the importance of identifying neglected sources of environmental contamination via the wastewater pathway. Additional monitoring and modeling studies are needed to inform source control and prevention of undesirable alternative solutions.

Sutton, R.; Lin, D.; Sedlak, M.; Box, C.; Gilbreath, A.; Holleman, R.; Miller, L.; Wong, A.; Munno, K.; Zhu, X.; et al. 2019. Understanding Microplastic Levels, Pathways, and Transport in the San Francisco Bay Region.  SFEI Contribution No. 950. San Francisco Estuary Institute: Richmond, CA.
Microplastics (particles less than 5 mm) are ubiquitous and persistent pollutants in the ocean and a pervasive and preventable threat to the health of marine ecosystems. Microplastics come in a wide variety of shapes, sizes, and plastic types, each with unique physical and chemical properties and toxicological impacts. Understanding the magnitude of the microplastics problem and determining the highest priorities for mitigation require accurate measures of microplastic occurrence in the environment and identification of likely sources.
To develop critical baseline data and inform solutions, the San Francisco Estuary Institute and the 5 Gyres Institute have completed the first comprehensive regional study of microplastic pollution in a major estuary. This project supported multiple scientific components to develop improved knowledge about and characterization of microparticles and microplastics in San Francisco Bay and adjacent National Marine Sanctuaries, with the following objectives:
<li>Contribute to the development and standardization of sample collection and analysis methodology for microplastic transportation research.</li><li>Determine a baseline for future monitoring of microplastics in San Francisco Bay surface water, sediment, and fish, and in ocean waters outside the Golden Gate.</li><li>Characterize pathways by which microplastics enter the Bay, including urban stormwater and treated wastewater effluent.</li><li>Investigate the contribution of Bay microplastics to the adjacent National Marine Sanctuaries through computer simulations.</li><li>Communicate findings to regional stakeholders and the general public through meetings and educational materials.</li><li>Facilitate evaluation of policy options for San Francisco Bay, with recommendations on source reduction.</li>This document presents the findings of this three-year project. A companion document, ?San Francisco Bay Microplastics Project: Science-Supported Solutions and Policy Recommendations,? has been developed by 5 Gyres using the findings of this study (Box and Cummins, 2019).

Lin, D.; Sutton, R. 2018. Alternative Flame Retardants in San Francisco Bay: Synthesis and Strategy.  SFEI Contribution No. 885. San Francisco Estuary Institute : Richmond, CA.

Lin, D.; Sutton, R.; Shimabuku, I.; Sedlak, M.; Wu, J.; Holleman, R. 2018. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations 2018 Update.  SFEI Contribution No. 873. San Francisco Estuary Institute: Richmond, CA.

Sedlak, M.; Sutton, R.; Wong, A.; Lin, D. 2018. Per and Polyfluoroalkyl Substances (PFAS) in San Francisco Bay: Synthesis and Strategy.  SFEI Contribution No. 867. San Francisco Estuary Institute : Richmond, CA.

Lin, D.; Sutton, R.; Sun, J.; Ross, J. 2018. Screening of Pharmaceuticals in San Francisco Bay Wastewater.  SFEI Contribution No. 910. San Francisco Estuary Institute : Richmond, CA.

Sutton, R.; Sedlak, M.; Sun, J.; Lin, D. 2017. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations. 2017 Revision.  SFEI Contribution No. 815. San Francisco Estuary Institute: Richmond, CA.

Wu, Y.; Tan, H.; Sutton, R.; Chen, D. 2017. From Sediment to Top Predators: Broad Exposure of Polyhalogenated Carbazoles in San Francisco Bay (U.S.A.). Environmental Science and Technology 51, 2038-2046.
The present study provides the first comprehensive investigation of polyhalogenated carbazoles (PHCZ) contamination in an aquatic ecosystem. PHCZs have been found in soil and aquatic sediment from several different regions, but knowledge of their bioaccumulation and trophodynamics is extremely scarce. This work investigated a suite of 11 PHCZ congeners in San Francisco Bay (United States) sediment and organisms, including bivalves (n = 6 composites), sport fish (n = 12 composites), harbor seal blubber (n = 18), and bird eggs (n = 8 composites). The most detectable congeners included 3,6-dichlorocarbazole (36-CCZ), 3,6-dibromocarbazole (36-BCZ), 1,3,6-tribromocarbazole (136-BCZ), 1,3,6,8-tetrabromocarbazole (1368-BCZ), and 1,8-dibromo-3,6-dichlorocarbazole (18-B-36-CCZ). The median concentrations of ?PHCZs were 9.3 ng/g dry weight in sediment and ranged from 33.7 to 164 ng/g lipid weight in various species. Biomagnification was observed from fish to harbor seal and was mainly driven by chlorinated carbazoles, particularly 36-CCZ. Congener compositions of PHCZs differed among species, suggesting that individual congeners may be subject to different bioaccumulation or metabolism in species occupying various trophic levels in the studied aquatic system. Toxic equivalent (TEQ) values of PHCZs were determined based on their relative effect potencies (REP) compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The median TEQ was 1.2 pg TEQ/g dry weight in sediment and 4.8 ? 19.5 pg TEQ/g lipid weight in biological tissues. Our study demonstrated the broad exposure of PHCZs in San Francisco Bay and their characteristics of bioaccumulation and biomagnification along with dioxin-like effects. These findings raise the need for additional research to better elucidate their sources, environmental behavior, and fate in global environments.

Sutton, R.; Sedlak, M. 2017. Microplastic Monitoring and Science Strategy for San Francisco Bay.  SFEI Contribution No. 798. San Francisco Estuary Institute: Richmond, Calif.

Sadaria, A. M.; Sutton, R.; Moran, K. D.; Teerlink, J.; Brown, J. V.; Halden, R. U. 2017. Passage of fiproles and imidacloprid from urban pest control uses through wastewater treatment plants in northern California. Environmental Toxicology and Chemistry 36, 1473-1482 . SFEI Contribution No. 783.
Urban pest control insecticides, specifically fipronil and its four major degradates (fipronil sulfone, sulfide, desulfinyl, and amide) and imidacloprid, were monitored during drought conditions in eight San Francisco Bay wastewater treatment plants (WWTPs). In influent and effluent, ubiquitous detections were obtained in units of ng/L for fipronil (13-88), fipronil sulfone (1-28), fipronil sulfide (1-5) and imidacloprid (58-306). In influent, 100% of imidacloprid and 62?±?9% of total fiproles (fipronil and degradates) were present in the dissolved state, with the balance being bound to filter-removable particulates. Targeted insecticides persisted during wastewater treatment, regardless of treatment technology utilized (imidacloprid: 93?±?17%; total fiproles: 65?±?11%), with partitioning into sludge (3.7-151.1??g/kg dry weight as fipronil) accounting for minor losses of total fiproles entering WWTPs. The load of total fiproles was fairly consistent across the facilities but fiprole speciation varied. This first regional study on fiprole and imidacloprid occurrences in raw and treated California sewage revealed ubiquity and marked persistence to conventional treatment of both phenylpyrazole and neonicotinoid compounds. Flea and tick control agents for pets are identified as potential sources of pesticides in sewage meriting further investigation and inclusion in chemical-specific risk assessments. 

Jabusch, T.; Sun, J.; Sutton, R.; Maruya, K.; Fadness, R. 2017. Pilot Study of Contaminants of Emerging Concern (CECs) in the Russian River Watershed: Lessons Learned.  SFEI Contribution No. 852. San Francisco Estuary Institute: Richmond, CA.

Sedlak, M.; Sutton, R.; Box, C.; Sun, J.; Lin, D. 2017. Sampling and Analysis Plan for Microplastic Monitoring in San Francisco Bay and Adjacent National Marine Sanctuaries.  SFEI Contribution No. 819. San Francisco Estuary Institute: Richmond, CA.

Sutton, R.; Sedlak, M.; Houtz, E. 2016. Identifying and Addressing Contaminant Sources Impacting an Urban Estuary.

Sutton, R. 2016. Microplastic Contamination in San Francisco Bay - Fact Sheet. 2015, Revised 2016.  SFEI Contribution No. 770.

Sutton, R.; Mason, S. A.; Stanek, S. K.; Willis-Norton, E.; Wren, I. F.; Box, C. 2016. Microplastic contamination in the San Francisco Bay, California, USA. Marine Pollution Bulletin 109 . SFEI Contribution No. 769.
Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000 particles/km2, Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff.

Houtz, E. F.; Sutton, R.; Park, J. - S.; Sedlak, M. 2016. Poly- and perfluoroalkyl substances in wastewater: Significance of unknown precursors, manufacturing shifts, and likely AFFF impacts. Water Research . SFEI Contribution No. 780.
In late 2014, wastewater effluent samples were collected from eight treatment plants that discharge to San Francisco (SF) Bay in order to assess poly- and perfluoroalkyl substances (PFASs) currently released from municipal and industrial sources. In addition to direct measurement of twenty specific PFAS analytes, the total concentration of perfluoroalkyl acid (PFAA) precursors was also indirectly measured by adapting a previously developed oxidation assay. Effluent from six municipal treatment plants contained similar amounts of total PFASs, with highest median concentrations of PFHxA (24 ng/L), followed by PFOA (23 ng/L), PFBA (19 ng/L), and PFOS (15 ng/L). Compared to SF Bay municipal wastewater samples collected in 2009, the short chain perfluorinated carboxylates PFBA and PFHxA rose significantly in concentration. Effluent samples from two treatment plants contained much higher levels of PFASs: over two samplings, wastewater from one municipal plant contained an average of 420 ng/L PFOS and wastewater from an airport industrial treatment plant contained 560 ng/L PFOS, 390 ng/L 6:2 FtS, 570 ng/L PFPeA, and 500 ng/L PFHxA. The elevated levels observed in effluent samples from these two plants are likely related to aqueous film forming foam (AFFF) sources impacting their influent; PFASs attributable to both current use and discontinued AFFF formulations were observed. Indirectly measured PFAA precursor compounds accounted for 33%?63% of the total molar concentration of PFASs across all effluent samples and the PFAA precursors indicated by the oxidation assay were predominately short-chained. PFAS levels in SF Bay effluent samples reflect the manufacturing shifts towards shorter chained PFASs while also demonstrating significant impacts from localized usage of AFFF.

Sutton, R.; Brown, J. V. 2016. The RMP Emerging Contaminants Program - Fact Sheet.  SFEI Contribution No. 778.

Sutton, R.; Kucklick, J. 2015. A Broad Scan of Bay Contaminants. San Francisco Estuary Institute: Richmond, CA.

Sutton, R.; Sedlak, M. 2015. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations. 2015 Update. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations.  SFEI Contribution No. 761. San Francisco Estuary Institute: Richmond, CA.
About this Update 
The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) has been investigating contaminants of emerging concern (CECs) since 2001. CECs can be broadly defined as synthetic or naturally occurring chemicals that are not regulated or commonly monitored in the environment but have the potential to enter the environment and cause adverse ecological or human health impacts.
The RMP Emerging Contaminants Workgroup (ECWG), established in 2006, includes representatives from RMP stakeholder groups, regional scientists, and an advisory panel of expert researchers that work together to address the workgroup?s guiding management question ? Which CECs have the potential to adversely impact beneficial uses in San Francisco Bay? The overarching goal of the ECWG is to develop cost-effective strategies to identify and monitor CECs to minimize impacts to the Bay.
To this end, the RMP published a CEC Strategy document in 2013 (Sutton et al. 2013). The strategy is a living document that guides RMP special studies on CECs, assuring continued focus on the issues of highest priority to the health of the Bay. A key focus of the strategy is a tiered risk and management action framework that guides future monitoring proposals. The strategy also features a multi-year plan indicating potential future research priorities.
This 2015 CEC strategy update features revised designations of CECs in the tiered risk and management action framework based on monitoring and research conducted since 2013. Brief summaries of relevant RMP findings are provided. In addition, a proposed multi-year plan for future RMP Special Studies on CECs is outlined. A full revision of the CEC strategy is anticipated in 2016. 

Sutton, R.; Sedlak, M.; Yee, D.; Davis, J. A.; Crane, D.; Grace, R.; Arsem, N. 2015. Declines in Polybrominated Diphenyl Ether Contamination of San Francisco Bay following Production Phase-Outs and Bans. Environmental Science and Technology 49 (2), 777-784 . SFEI Contribution No. 742.

Stanek, S. K.; Sutton, R.; Mason, S. A.; Willis-Norton, E.; Wren, I. F.; Box, C. 2015. Microplastic Contamination in San Francisco Bay.

Sutton, R.; Chen, D.; Sedlak, M. 2014. Alternative Flame Retardants in San Francisco Bay.

Sutton, R.; Sedlak, M.; Davis, J. A. 2014. Polybrominated Diphenyl Ethers (PBDEs) in San Francisco Bay: A Summary of Occurrence and Trends.  SFEI Contribution No. 713. San Francisco Estuary Institute: Richmond, CA. p 62.

Sutton, R.; Sedlak, M.; Yee, D. 2013. Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations. San Francisco Estuary Institute: Richmond, CA.

Klosterhaus, S.; Yee, D.; Sedlak, M.; Wong, A.; Sutton, R. 2013. Contaminants of Emerging Concern in San Francisco Bay: A Summary of Occurrence Data and Identification of Data Gaps.  SFEI Contribution No. 698. p 121.

Yee, D.; Sutton, R.; Davis, J. A.; Sedlak, M. 2013. PBDES in the San Francisco Bay Food Web.

Eastman, R.; Sutton, R. 2013. Pharmaceuticals and Personal Care Products in San Francisco Bay.