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This report presents a strategy and multi-year workplan for modeling polychlorinated biphenyls (PCBs), contaminants of emerging concern (CECs), and sediment in San Francisco Bay (the Bay). Robust in-Bay fate modeling is needed to address priority management questions that have been identified for these constituents.

The strategy for in-Bay modeling presented in this report is a major element of a broader, integrated strategy that is being developed across RMP Workgroups for modeling contaminants flowing from the Bay watersheds and other pathways into the Bay. The broader project is expected to yield an integrated strategy in 2022, followed by implementation of a pilot effort in 2023. Coordination of the in-Bay modeling effort with the broader integrated strategy and other modeling work (e.g., nutrient modeling under the Nutrient Management Strategy) will be critical to optimizing use of the funds allocated to modeling.

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.

This document summarizes a study conducted for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) to re-evaluate the use of the Floating Percentile Method
(FPM) to derive sediment screening guidelines for dredged material reuse in the San Francisco Bay Region. The Long Term Management Strategy (LTMS) has a goal to use at least 40% of the sediment dredged from San Francisco Bay for beneficial reuse (USACE, 1998). The suitability of dredged sediment for beneficial reuse is in part determined by concentrations of toxic pollutants.The San Francisco Regional Water Quality Control Board (SFB-RWQCB) issued draft screening criteria in 2000 to categorize the suitability of sediment for reuse as either “surface” sediment, that may be placed near the surface for re-use in wetlands, or “foundation” sediment, that is buried under sediment that meets surface criteria. Contaminant concentration guidelines for surface sediment are lower than foundation sediment, based on the assumption that biota are more likely to be exposed to surface sediment than deeper foundation sediment.

The purpose of this document is to guide efforts and summarize plans developed within the RMP. The intended audience includes representatives of the many organizations who directly participate in the Program. This document will also be useful for individuals who are not directly involved with the RMP but are interested in an overview of the Program and where it is heading.  

The organization of this Multi-Year Plan parallels the RMP planning process (Figure 2). Section 1 presents the long-term management plans of the agencies responsible for managing water quality in the Bay and the overarching management questions that guide the Program. The agencies’ long-term management plans provide the foundation for RMP planning (Figure 2). In order to turn the plans into effective actions, the RMP distills prioritized lists of management questions that need to be answered (Page 8). The prioritized management questions then serve as a roadmap for scientists on the Technical Review Committee, workgroups, and strategy teams to plan and implement scientific studies to address the most urgent information needs. This information sharpens the focus on management actions that will most effectively and efficiently improve water quality in the Bay. 

Monitoring of sport fish and water was conducted by the Delta Regional Monitoring Program (Delta RMP) from August 2016 to April 2017 to begin to address the highest priority information needs related to implementation of the Sacramento–San Joaquin Delta Estuary Total Maximum Daily Load (TMDL) for Methylmercury (Wood et al. 2010). Two species of sport fish, largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus), were collected at six sampling locations in August and September 2016. The length-adjusted (350 mm) mean methylmercury (measured as total mercury, which is a routinely used proxy for methylmercury in predator fish) concentration in bass ranged from 0.15 mg/kg or parts per million (ppm) wet weight at Little Potato Slough to 0.61 ppm at the Sacramento River at Freeport. Water samples were collected on four occasions from August 2016 through April 2017. Concentrations of methylmercury in unfiltered water ranged from 0.021 to 0.22 ng/L or parts per trillion. Concentrations of total mercury in unfiltered water ranged from 0.91 to 13 ng/L.

Over 99% of the lab results for this project met the requirements of the Delta RMP Quality Assurance Program Plan, and all data were reportable. This data report presents the methods and results for the first year of monitoring. Historic data from the same or nearby monitoring stations from 1998 to 2011 are also presented to provide context. Monitoring results for both sport fish and water were generally comparable to historic observations.

For the next several years, annual monitoring of sport fish will be conducted to firmly establish baseline concentrations and interannual variation in support of monitoring of long-term trends as an essential performance measure for the TMDL. Monitoring of water will solidify the linkage analysis (the quantitative relationship between methylmercury in water and methylmercury in sport fish) in the TMDL. Water monitoring will also provide data that will be useful in verifying patterns and trends predicted by numerical models of mercury transport and cycling being developed for the Delta and Yolo Bypass by the California Department of Water Resources (DWR).

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.

The Bay margins (i.e., mudflats and adjacent shallow areas of the Bay) are important habitats where there is high potential for wildlife to be exposed to contaminants. However, until recently, these areas had not been routinely sampled by the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) due to logistical considerations. In 2015, the RMP conducted a spatially-distributed characterization of surface sediment contamination and ancillary characteristics within the RMP-defined Central San Francisco Bay margin areas. This was repeated in 2017 within South Bay, which for this report refers to the area collectively encompassing Upper South Bay (usually just called the “South Bay” segment in the Bay RMP, “Upper” added here to distinguish from the combined area), Lower South Bay, and “Extreme” Lower South Bay (previously named “Southern Sloughs”) margin areas.

Ambient margins data in South Bay provide a context against which the severity of contamination at specific sites can be compared. The baseline data could also be useful in setting targets and tracking improvements in watershed loads and their nearfield receiving waters, or for appropriate assessment of re-use or disposal of dredged sediment. These spatially distributed data also provide improved estimates of mean concentrations and contaminant inventories in margins. Based on data from this study, contamination in the margin areas accounts for 35% of PCB mass in the upper 15 cm of surface sediments in South Bay, which is approximately proportional to the relative area of the margin (34% of the region). In contrast, margins only contain 30% of the mercury mass in South Bay, somewhat less than their proportional area.

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. 

The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) monitors concentrations of contaminants in fish tissue as indicators of bioaccumulation of contaminants in the Bay. In 2019, the RMP will conduct its eighth round of sport fish monitoring by collecting sport fish samples from various locations in the Bay as a part of routine Status and Trends Monitoring. Add-ons to the routine Status and Trends sport fish monitoring design will include archiving for microplastics and fipronil, as well as additional collections of shiner surfperch in Priority Margin Unit areas (PMUs).

The goal of monitoring for selenium in the North Bay tissue and water is to identify leading indicators of change to allow prompt management response to signs of increasing impairment. At the 2016 technical workshop, participants reached a consensus that monitoring sturgeon, clams, and water are all needed to answer management questions. Recommendations for long-term monitoring of these three matrices are detailed in the North Bay Monitoring Design document (Grieb et al. 2018). The purpose of this Sampling and Analysis Plan is to clearly document the sampling design, methods, and responsibilities; and to facilitate coordination among project partners.

This memo provides a high-level summary of the quality assurance assessment for data reported by the RMP.  In 2019, fish tissue samples were collected from nine Bay/Delta areas and three additional wetland/slough areas for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). General descriptions of the sample collection methods are provided in the RMP Quality Assurance Program Plan, cruise plans, cruise reports, and field sampling reports. These documents are available from the SFEI website (http://www.sfei.org/content/status-and-trends-monitoring-documents).

In 2018, bivalve tissue samples were collected from six Bay/Delta stations and a reference site for the Regional Monitoring Program for Water Quality in San Francisco Bay. Bird egg tissue samples were collected from two sites for cormorants, and four sites for terns. General descriptions of the sample collection methods are provided in the RMP Quality Assurance Program Plan, cruise plans, cruise reports, and sampling reports. These documents are available from the SFEI website (http://www.sfei.org/content/status-and-trends-monitoring-documents)

In 2018, sediment samples were collected from 27 stations (7 historical sites, with the rest from the GRTS random draw panels) for the Regional Monitoring Program for Water Quality in San Francisco Bay. The details of the cruise and sample collection methods are described in the RMP Quality Assurance Program Plan, cruise plans, cruise reports, and field sampling reports. These documents are available from the SFEI website (http://www.sfei.org/content/status-and-trends-monitoring-documents).