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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.

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.

The Dredged Material Management Office (DMMO) is responsible for annually approving dredging and disposal of millions of cubic yards of sediment to maintain safe navigation in San Francisco Bay. Dredged sediment is characterized for physical, chemical, and biological characteristics to ensure sediment disposed of in the Bay or at beneficial use locations does not cause adverse environmental impacts. Bioaccumulation thresholds and total maximum daily loads (TMDLs) have been established for several contaminant classes, including PCBs, and are used by the DMMO to determine whether sediment contaminant levels trigger subsequent bioaccumulation testing. Sediment with contaminant concentrations above any TMDL levels cannot be disposed of within the Bay but may be further evaluated for upland reuse and ocean disposal. The objective of this study was to evaluate PCB bioaccumulation data from navigational dredging projects to assess the existence of correlations between sediment chemistry and bioaccumulation test results. The motivation for this study was to determine whether the current PCB bioaccumulation trigger is effective in differentiating sediment bioaccumulation concerns. The DMMO may use the results of this study to inform evaluation requirements for PCBs, particularly in support of modifying the terms of the Long-term Management Strategy for San Francisco Bay (LTMS) programmatic Essential Fish Habitat (EFH) agreement concerning PCB bioaccumulation testing. 

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.

Ultraviolet (UV) radiation filters are chemicals designed to absorb or reflect harmful solar radiation, and are used in products as diverse as personal care products (e.g., sunscreens, lotions, and cosmetics) and industrial products (e.g., insecticides, plastics, and paints) to mitigate deleterious effects of sunlight and extend product life. Widespread use of UV filters has led to extensive detections in the environment, and have raised concerns about impacts to aquatic ecosystems. In particular, several organic UV filters that are commonly used in sunscreen have been identified as neurotoxins and endocrine disruptors. To help understand the presence of organic UV filters and their potential to pose risks in San Francisco Bay, three of the most commonly used organic UV filters used in sunscreen (avobenzone, octinoxate, oxybenzone) as well as select metabolites were analyzed in municipal wastewater effluent from the six largest publicly-owned treatment works (POTWs) discharging into the Bay. Note that organic UV filters is a broad chemical class, and other constituents within this class were not included in this study.

Only two of the three organic UV filters analyzed were detected in effluent, avobenzone (detected in 70% of samples) and oxybenzone (83%), with median concentrations of 28 and 86 ng/L, and 90th percentile concentrations of 77 and 209 ng/L, respectively. Concentrations of avobenzone and oxybenzone varied widely across facilities, though there were no clear outlier values. The two POTWs utilizing advanced secondary treatment had the lowest concentrations of any facilities, which may indicate increased removal from these processes. Overall, these concentrations were higher than those reported in one other study of wastewater effluent in the US. An increasing body of literature will help to fully understand the occurrence and fate of organic UV filters in wastewater.

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.  

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.

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.

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.

Trash has received renewed focus in recent years as policy makers, public agencies, environmental organizations, and community groups have taken many steps towards trash quantification and management across California. The range of management actions is matched by the diversity of monitoring approaches, designed to determine key attributes associated with trash pollution on California’s lands and in its waterways.

This report describes the field testing associated with a project designed to validate the accuracy, precision, and practicality of several trash monitoring methods, practiced across the state. Additionally, the project measured the efficacy of a novel monitoring method designed to detect trash via remote sensing and machine learning. Readers will find details about each respective method -- the specific approach to
landscape characterization, the qualitative or quantitative measures undertaken, the team-based quality assurance for data collection -- as well as the approach that the testing team adopted to ensure efficient, accurate, and useful validation of the methods.

Because the validation efforts integrated multiple methods, using multiple teams at a selection of common sites, the field testing report yields useful statistical information not only about each method individually, but about the comparability of the results. The report illustrates the
correlation factor associated with different forms of trash metrics, associated with different methods practiced on the same assessment sites. The results illustrated a generally high degree of correlation among different methods, which promises opportunities to compare results meaningfully across methods.

Furthermore, this field testing report provides quantitative measures to illustrate the repeatability of each method, the differences and insights yielded by assessment site sizing criteria varying among methods, the transferability / teach-ability of each method among trash monitoring practitioners, and how the degrees of accuracy might aid programs in performing mass balance analysis of known sources
to trash detected in a given site.

Regarding innovation, the project team leveraged multiple on-the-ground methods and special testing scenarios to compare conventional and novel (aerial) assessments to measure the relative accuracy and precision of this emergent technology that might address some of the resource constraints that currently limit the broader or more frequent deployment of conventional trash assessment methods. The analyses captured in this field testing report offer specific quantitative measures of the accuracy (bias), precision (repeatability), practicality and cost associated with each method. This information is subsequently used to inform a companion summary analysis found in the Trash Monitoring Playbook, which is designed to evaluate the applicability of the monitoring methods to address classes of
monitoring questions.

As municipalities and water-quality regulatory agencies have implemented programs and policies to improve management of the trash loading to storm drain conveyances, there has been increased interest in using a common set of methods to quantify the effectiveness of management actions. To create a foundation for developing a consistent, standardized approach to trash monitoring statewide, the project team performed a method comparison analysis, based on two seasons of fieldwork. This analysis facilitated the assessment of the accuracy, repeatability, and efficiency of some already developed trash monitoring methodologies already in use, as well as help to investigate a new, innovative method (cf. Fielding Testing Report on trashmonitoring.org). Methods developed by the Bay Area Stormwater Management Agencies Association (BASMAA) for use in the San Francisco Bay Area were compared to methods developed by the Southern California Stormwater Monitoring Coalition (SMC) for use in coastal southern California. One of the chief goals of these comparisons was to understand the similarities and differences between the already existing methods for detecting, quantifying, and characterizing trash in selected environments. Readers will find that the data bear out remarkable levels of accuracy and precision with quantitative metrics that help to align methods and management concerns. Furthermore, the degree of correlation among tested methods were especially high, offering greater opportunities for inter-method comparisons.

The findings of this project are intended for use by public agencies, non-profit organizations, private consultants, and all of their various partners in informing a statewide effort to adopt rigorous, standardized monitoring methods to support the State Water Board’s Trash Amendments. Over the next couple of decades, such public mandates will require all water bodies in California to achieve water quality objectives for trash.

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.

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 [email protected] for the materials.

As we drive our cars, our tires shed tiny particles

When it rains, stormwater runoff carries tire particles—and the toxic chemicals they contain—from city streets and highways to storm drains and fish habitat in creeks and estuaries like San Francisco Bay. Stormwater washes trillions of tire particles into the Bay each year.

How do tires affect wildlife?

A recent study found a highly toxic chemical (“6PPD-quinone”) derived from vehicle tires in Bay Area stormwater at levels that are lethal to coho salmon. New data indicate that steelhead, a salmon species still migrating through the Bay to surrounding watersheds, are also sensitive to this chemical.

Quantitative, broadly applicable metrics of resilience are needed to effectively manage tidal marshes into the future. Here we quantified three metrics of temporal marsh resilience: time to marsh drowning, time to marsh tipping point, and the probability of a regime shift, defined as the conditional probability of a transition to an alternative super-optimal, suboptimal, or drowned state. We used organic matter content (loss on ignition, LOI) and peat age combined with the Coastal Wetland Equilibrium Model (CWEM) to track wetland development and resilience under different sea-level rise scenarios in the Sacramento-San Joaquin Delta (Delta) of California. A 100-year hindcast of the model showed excellent agreement (R2 = 0.96) between observed (2.86 mm/year) and predicted vertical accretion rates (2.98 mm/year) and correctly predicted a recovery in LOI (R2 = 0.76) after the California Gold Rush. Vertical accretion in the tidal freshwater marshes of the Delta is dominated by organic production. The large elevation range of the vegetation combined with high relative marsh elevation provides Delta marshes with resilience and elevation capital sufficiently great to tolerate centenary sea-level rise (CLSR) as high as 200 cm. The initial relative elevation of a marsh was a strong determinant of marsh survival time and tipping point. For a Delta marsh of average elevation, the tipping point at which vertical accretion no longer keeps up with the rate of sea-level rise is 50 years or more. Simulated, triennial additions of 6 mm of sediment via episodic atmospheric rivers increased the proportion of marshes surviving from 51% to 72% and decreased the proportion drowning from 49% to 28%. Our temporal metrics provide critical time frames for adaptively managing marshes, restoring marshes with the best chance of survival, and seizing opportunities for establishing migration corridors, which are all essential for safeguarding future habitats for sensitive species.

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.

In response to the widely recognized negative impacts of urbanization on biodiversity, many cities are reimagining urban design to provide better biodiversity support. Some cities have developed urban biodiversity plans, primarily focused on improving biodiversity support and ecosystem function within the built environment through habitat restoration and other types of urban greening projects. The biophilic cities movement seeks to reframe nature as essential infrastructure for cities, seamlessly integrating city and nature to provide abundant, accessible nature for all residents and corresponding health and well-being outcomes. Urban biodiversity planning and biophilic cities have significant synergies in their goals and the means necessary to achieve them. In this paper, we identify three key ways by which the urban biodiversity planning process can support biophilic cities objectives: engaging the local community; identifying science-based, quantitative goals; and setting priorities for action. Urban biodiversity planning provides evidence-based guidance, tools, and techniques needed to design locally appropriate, pragmatic habitat enhancements that support biodiversity, ecological health, and human health and well-being. Developing these multi-functional, multi-benefit strategies that increase the abundance of biodiverse nature in cities has the potential at the same time to deepen and enrich our biophilic experience in daily life.

Meeting human and ecological needs within San Francisco Bay’s watersheds is increasingly challenged by flooding, water quality degradation, and habitat loss, exacerbated by intensified urbanization and climate change. Addressing these challenges requires implementing multi-benefit strategies through new partnerships and increased coordination across the region’s diverse landscapes. Actions to improve water quality and enhance habitat for biodiversity in our highly developed and managed landscapes can help the region as a whole to build resilience to withstand current pressures and future change. The EPA-funded project, “Preparing for the Storm,” aims to address these challenges at the site- and landscape-scale through studies and implementation projects in the Livermore-Amador Valley. As part of this larger project, this technical report presents a synthesis of water quality and habitat improvement opportunities for a golf course of Castlewood Country Club.

The “Sycamore Alluvial Woodland Restoration and Enhancement Suitability Study” addresses distribution and regeneration patterns and restoration strategies of sycamore alluvial woodland (SAW) habitat, a unique and relatively rare native vegetation community adapted to California’s intermittent rivers and streams. The report was produced by SFEI and H. T. Harvey & Associates, as part of the US EPA Water Quality Improvement Fund Preparing for the Storm grant, led by Zone 7 Water Agency.

The Preparing for the Storm project, led by Zone 7 Water Agency (Zone 7) and funded by the US Environmental Protection Agency (EPA) Water Quality Improvement Fund, aims to develop science-based plans, strengthen existing and new partnerships, and pilot new methodologies for tackling these issues surrounding coarse sediment. As a task within this larger project, this report describes four projects in the East Bay that serve as case studies for beneficial reuse of sediment. Each example highlights a project with sediment that could be reused (in lieu of landfilling) or a project that needs additional sediment and could benefit from deliveries of sediment that normally would not have been beneficially reused.