2017 Update to Cyanide Rolling Average

San Francisco Estuary Institute (SFEI) | July 1st, 2018

As part of the site-specific objectives (SSO), NPDES dischargers are required to calculate the 3-event rolling average of dissolved copper and total cyanide concentration

As part of the site-specific objectives (SSO), NPDES dischargers are required to calculate the 3-event rolling average of dissolved copper and total cyanide concentrations in each segment of the Bay, based on RMP data.

2018 Regional Monitoring Plan (RMP) Bird Egg Monitoring Sampling and Analysis Plan

San Francisco Estuary Institute (SFEI) | March 5th, 2018

The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) monitors concentrations of contaminants in bird egg tissue as an indicator of water quality.

The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) monitors concentrations of contaminants in bird egg tissue as an indicator of water quality. In 2018, the RMP will collect bird egg samples from various locations in the Bay as part of routine Status and Trends Monitoring. The target species will be Double-crested Cormorants and Forster’s Terns.

2019 Annual Report on the Salton Sea Management Program

California Natural Resources Agency (CNRA) | March 1st, 2019

On November 7, 2017, the State Water Resources Control Board adopted an order accepting an agreement defining the state’s commitment to stabilize and manage the Salton

On November 7, 2017, the State Water Resources Control Board adopted an order accepting an agreement defining the state’s commitment to stabilize and manage the Salton Sea to protect public health and critical Pacific flyway habitat.  Order WR 2017-0134 outlined the State Water Board’s oversight role in monitoring and ensuring progress toward the goals of the Salton Sea Management Plan (SSMP), which sets annual milestones for habitat restoration and dust-suppression projects over the next 10 years. 

2019 Regional Monitoring Plan (RMP) North Bay Selenium Monitoring Sampling and Analysis Plan

San Francisco Estuary Institute (SFEI) | January 31st, 2020

In 2016, the State Water Resources Control Board approved a selenium TMDL for North San Francisco Bay. The TMDL established a target concentration of 11.3 ug/g dw in whi

In 2016, the State Water Resources Control Board approved a selenium TMDL for North San Francisco Bay. The TMDL established a target concentration of 11.3 ug/g dw in white sturgeon muscle tissue as the basis for evaluating impairment (SFBRWQCB 2015). Following discussions surrounding the North Bay TMDL, the San Francisco Bay Regional Water Quality Control Board asked the RMP Selenium Workgroup to develop a robust monitoring design for North Bay. The goal of the monitoring 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 USGS conducted monthly clam monitoring at multiple locations in North Bay for over 20 years, but USGS funding for this work ended in 2016. In 2019, the RMP will resume clam monitoring following a modified monitoring design optimized for early detection of changes in selenium trends in clams. These efforts will continue the long-term monitoring of Potamocorbula amurensis. Grieb et al. (2018) also recommended monitoring dissolved and particulate selenium in the water column. Long-term monitoring of water and sturgeon tissue in North Bay will be added to the clam sampling to track interannual trends and changes in sources or environmental processes influencing food web selenium exposures in North Bay. Potamocorbula amurensis and water samples will be collected from two long-term USGS monitoring locations in northern San Francisco Bay. Samples will be collected and processed by SFEI and Applied Marine Sciences (AMS) aboard the R/V Questuary . Sampling will take place over six months each year in two key three-month periods: July-September and December-February. White sturgeon ( Acipenser transmontanus ) samples will be collected by DFW during their tagging efforts aboard the New Alosa . These efforts occur during DFW’s fall tagging cruises (Sept - Oct). Non-lethal muscle plug samples will be collected from the epaxial muscle of each fish, just in front of the dorsal fin (Figure 5). Brooks Applied Labs (BAL), CalTest Analytical Laboratory (CalTest), and the UC Davis Stable Isotope Lab will be the analytical partners for this work. Stable isotope analysis will be used to identify spatial and temporal relationships within a food web, as well as potential sources of selenium. BAL will analyze dissolved and particulate selenium in water; clams, and sturgeon samples; and CalTest will conduct ancillary analyses on dissolved water samples. 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.

2019 Regional Monitoring Program (RMP) Sport Fish Monitoring Sampling and Analysis Plan

San Francisco Estuary Institute (SFEI) | December 1st, 2019

2020 Annual Report on the Salton Sea Management Program

California Natural Resources Agency (CNRA) | February 21st, 2020

Improving air quality and creating habitat at the Salton Sea are key priorities for Governor Gavin Newsom and the California Natural Resources Agency. The Sea’s continu

Improving air quality and creating habitat at the Salton Sea are key priorities for Governor Gavin Newsom and the California Natural Resources Agency. The Sea’s continuing decline in elevation and resulting exposure of lakebed negatively impact surrounding communities and reduce remaining habitat for fish and wildlife. The California Natural Resources Agency, the California Department of Water Resources, and the California Department of Fish and Wildlife (together, the State Team) are focused on implementing the Salton Sea Management Program’s (SSMP’s) 10-Year Plan to improve conditions by constructing 30,000 acres of habitat and dust suppression projects around the Sea.

2021 RMP Water Cruise Plan

San Francisco Estuary Institute (SFEI) | October 14th, 2021

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 samplin

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.

6PPD-quinone in water from the San Francisco-San Joaquin Delta, California, 2018-2024

Nature Portfolio (Springer Nature) | March 10th, 2025

The Sacramento-San Joaquin Delta (Delta) is an expansive river delta supplying a large portion of California’s fresh water for agriculture and residential use, and it i

The Sacramento-San Joaquin Delta (Delta) is an expansive river delta supplying a large portion of California’s fresh water for agriculture and residential use, and it is also an area of critical habitat for numerous state and federally listed species of concern. In many locations, urban stormwater flows directly into the Delta. 6PPD-quinone (6PPD-Q), an ozonation byproduct of a tire antiozonant 6PPD, has been shown to enter surface water via these pathways and can cause various toxicological effects, including acute urban mortality syndrome to coho salmon (Oncorhynchus kisutch) at low levels (LC50 = 41 and 95 ng/L for juveniles and adults, respectively). Here, we quantified 6PPD-Q in 61 archived Delta water extracts collected between 2018 and 2024 and found concentrations up to 21 ng/L. Currently, no 6PPD-Q presence and/or quantitative data is available for this complex and diverse ecosystem. Little is known regarding long-term storage of 6PPD-quinone in solvent extracts, so 6PPD-Q observations document its presence in the study area and provide evidence that further sampling may be warranted to better quantify environmental concentrations. Consistent with the general understanding of 6PPD-Q transport, all detections observed were in samples collected during or immediately after a precipitation event. This work provides environmentally relevant concentration data to complement ongoing toxicological investigations of 6PPD-Q in Delta organisms and suggests there are research opportunities for a more robust survey of 6PPD-Q inputs into the Delta.

70 analyte PFAS test method highlights need for expanded testing of PFAS in drinking water

Science of the Total Environment (Elsevier) | April 12th, 2023

n this community-led pilot study we sought to investigate the utility of expanded per- and polyfluoroalkyl substances (PFAS) testing for drinking water, using a targeted

n this community-led pilot study we sought to investigate the utility of expanded per- and polyfluoroalkyl substances (PFAS) testing for drinking water, using a targeted analysis for 70 PFAS and the Total Oxidizable Precursor (TOP) Assay which can indicate the presence of precursor PFAS. PFAS were detected in 30 out of 44 drinking water samples across 16 states; 15 samples would exceed US EPA's proposed maximum contaminant levels for six PFAS. Twenty-six unique PFAS were identified, including 12 not covered by either US EPA Methods 537.1 or 533. An ultrashort chain PFAS, PFPrA, had the highest frequency of detection, occurring in 24 of 30 samples. It was also the PFAS reported at the highest concentration in 15 of these samples. We created a data filter to model how these samples would be reported under the upcoming fifth Unregulated Contaminant Monitoring Rule (UCMR5) requirements. All of the 30 samples with PFAS quantified by the 70 PFAS test had one or more PFAS present that would not be captured if the UCMR5 reporting requirements were followed. Our analysis suggests the upcoming UCMR5 will likely underreport PFAS in drinking water, due to limited coverage and higher minimum reporting limits. Results were inconclusive on the utility of the TOP Assay for monitoring drinking water. The results from this study provide important information to community participants regarding their current PFAS drinking water exposure. In addition, these results suggest gaps that need to be addressed by regulatory and scientific communities, in particular, the need for expanded targeted analysis of PFAS, the development of a sensitive, broad spectrum PFAS test, and further investigation into ultrashort chain PFAS.

A 450-year record of environmental change from Castle Lake, California (USA), inferred from diatoms and organic geochemistry

Journal of Paleolimnology (Springer) | November 11th, 2020

A 39-cm sediment core from Castle Lake, California (USA) spans the last ~ 450 years and was analyzed for diatoms and organic geochemistry (δ15N, δ13C, and C:N), wi

A 39-cm sediment core from Castle Lake, California (USA) spans the last ~ 450 years and was analyzed for diatoms and organic geochemistry (δ15N, δ13C, and C:N), with the goal of determining sensitivity to natural climate variation and twentieth century anthropogenic effects. Castle Lake is a subalpine, nitrogen-limited lake with ~ 5 months of annual ice cover. Human impacts include light recreational use, past fish stocking, and experimental use by the Castle Lake Research Station. The base of the core (below 32 cm; pre mid-1700s) represents the period of maximum ice cover. In contrast, the end of the Little Ice Age (mid 1700s–early 1800s) is dominated by cyclotelloids (mostly Discostella stelligera), indicating significant open-water periods, a condition that persisted into the early 1900s. Cyclotelloids began to decline in the 1960s and were replaced by the Fragilaria tenera grp. (peak in 1970s), succeeded by Asterionella formosa (peak ~ 2010), and accompanied by a reduction in δ15N values and a decrease in C:N that may represent increased atmospheric nitrogen deposition. Another anthropogenic signal was discerned in the core and was interpreted to be the result of an ammonium nitrate fertilization experiment of the epilimnion that was conducted in 1980 and 1981. This signal was manifested in the core largely by a negative excursion in δ15N, possibly caused by fractionation during denitrification in surface sediment. A phytoplankton monitoring dataset collected by the Castle Lake Research Station from 1967 to 1984 corroborates the timing of increased araphid euplanktonic species in the 1970s, and increases in two benthic diatoms (Staurosirella pinnata and Tabellaria fenestrata), entrained in the phytoplankton tows during the experimentation years. Both ice cover and nitrogen addition appear to be strong drivers that affected the lake diatoms, although additional drivers, such as fish stocking and associated cascade effects need further exploration. These data will be helpful for interpreting longer core records from Castle Lake, should the opportunity arise, as well as cores from similar systems in the region.