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This technical report describes the ten-year ambient stream condition reassessment survey design and monitoring plan (or strategy) for the Coyote Creek watershed. Because the reassessment employed (and modified) the 2010 sample draw, essential background information about the original 2010 probability-based survey design, sample draw, and field assessment outcomes were provided.

This report describes the amount and distribution of aquatic resources in the Coyote Creek watershed, Santa Clara County, California, and presents the first reassessment of stream ecosystem conditions using a watershed approach and the California Rapid Assessment Method (CRAM). Field work was conducted in 2020, ten years after the baseline watershed assessment completed in 2010.

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.

Sediment is a lifeblood of San Francisco Bay (Bay). It serves three key functions: (1) create and maintain tidal marshes and mudflats, (2) transport nutrients and contaminants, and (3) reduce impacts from excessive human-derived nutrients in the Bay. Because of these important roles, we need a detailed understanding of sediment processes in the Bay.

This report offers a conceptual understanding of how fine-grained sediment (i.e. silt and finer, henceforth called fine sediment) moves around at different scales within the Bay, now and into the future, to synthesize current knowledge and identify critical knowledge gaps. This information can be used to support Bay sediment management efforts and help prioritize funding for research and monitoring. In particular, this conceptual understanding is designed to inform future San Francisco Bay Regional Monitoring Program (RMP) work under the guidance of the Sediment Workgroup of the RMP for Water Quality in San Francisco Bay, which brings together experts who have worked on many different components of the landscape, including watersheds and tributaries, marshes and mudflats, beaches, and the open Bay. This report describes sediment at two scales: a conceptual understanding of open-Bay sediment processes at the Bay and subembayment scale (Chapter 2); and a conceptual understanding of sediment processes at the baylands scale (Chapter 3). Chapter 4 summarizes the key knowledge gaps and provides recommendations for future studies.

The goal of RMP PCB special studies over the next few years is to inform the review and possible revision of the PCB TMDL and the reissuance of the Municipal Regional Permit for Stormwater, both of which are tentatively scheduled to occur in 2020. Conceptual model development for a set of four representative priority margin units will provide a foundation for establishing an effective and efficient monitoring plan to track responses to load reductions, and will also help guide planning of management actions. The Emeryville Crescent was the first PMU to be studied in 2015-2016. The San Leandro Bay PMU is second (2016-2018), Steinberger Slough in San Carlos is third (2018), and Richmond Harbor will be fourth (2018-2019).

This document is Phase Three of a report on the conceptual model for San Leandro Bay. A Phase One report (Yee et al. 2017) presented analyses of watershed loading, initial retention, and long-term fate, including results of sediment sampling in 2016. A Phase Two data report (Davis et al. 2017) documented the methods, quality assurance, and all of the results of the 2016 field study. This Phase Three report is the final report that incorporates all of the results of the 2016 field study, and includes additional discussion of the potential influence of contaminated sites in the
watershed, the results of passive sampling by Stanford researchers and a comparative analysis of long-term fate in San Leandro Bay and the Emeryville Crescent, a section on bioaccumulation, and a concluding section with answers to the management questions that were the impetus for the work.

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 runoff has been identified in water quality policy documents for San Francisco Bay as a large and potentially controllable source of pollutants. In response, concentrations of suspended sediments and a range of trace organic pollutants were intensively measured in dry weather and storm flow runoff from a 100% urban watershed. Flow in this highly urban watershed responded very quickly to rainfall and varied widely resulting in rapid changes of turbidity, suspended sediments and pollutant concentrations. Concentrations of each organic pollutant class were within similar ranges reported in other studies of urban runoff, however comparison was limited for several of the pollutants given information scarcity. Consistently among PCBs, PBDEs, and PAHs, the more hydrophobic congeners were transported in larger proportions during storm flows relative to low flows. Loads for Water Years 2007-2010 were estimated using regression with turbidity during the monitored months and a flow weighted mean concentration for unmonitored dry season months. More than 91% of the loads for every pollutant measured were transported during storm events, along with 87% of the total discharge. While this dataset fills an important local data gap for highly urban watersheds of San Francisco Bay, the methods, the uniqueness of the analyte list, and the resulting interpretations have applicability for managing pollutant loads in urban watersheds in other parts of the world.