Contaminant Data Display and Download (CD3) is a web-based visualization tool for accessing water quality data for the San Francisco Bay-Delta region, including the Bay Regional Monitoring Program’s long-term dataset. The tool has been redesigned to leverage other interactive mapping efforts and offers impressive new functionality, including enhanced spatial querying and dynamic statistical summaries and charts. All public data uploaded to SFEI-ASC's Regional Data Center, including data beyond the San Francisco Bay-Delta, are available through this tool.

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1. What data are available?

Data from different programs throughout California are available in CD3. Data are refreshed weekly and include data uploaded to CEDEN. Rejected data are not displayed in CD3.

Click here for summary information on each dataset and consult the Field Definitions page for descriptions of the fields included in the data download.

Number of Projects
Total records
Total SF Bay RMP records
Number of unique analytes

2. Are data comparable to CEDEN?

Yes, all data are stored in SFEI’s Regional Data Center database and follow the California Environmental Data Exchange Network’s (CEDEN) data standards and business rules. CEDEN's controlled vocabulary lists or codes are located here.

3. How often are data updated?

Data displayed in CD3 are updated on a weekly basis.

4. Who should I contact if I have questions, find any errors, or would like to upload new data?

SFEI’s Data Services Team at [email protected] can answer any questions, address errors, or help you with uploading new data to SFEI’s Regional Data Center database and to CEDEN.

5. Are results expressed in wet weight or dry weight?

The Units field indicates if a result is expressed in wet weight (ww) or dry weight (dw).

6. How can I get a copy of a program or project’s Quality Assurance Plan (QAPP)?

Contact SFEI’s Data Services Team at [email protected]. Please note that not all data providers send SFEI a copy of their QAPP.

7. What are the data handling rules for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP)?

The results provided by CD3 may differ slightly from those previously reported in RMP annual reports, since results are updated as needed to address data errors and meet standardization requirements of the state. Measurements vary by year and test material, but typically include a suite of contaminants (metals and organics) and ancillary data. Missing data are either not available (e.g., parameters were not measured in every year), or the data are being reanalyzed and will be made available at a later date.

Missing data and changes in target RMP parameters are listed in the RMP Annual Monitoring Results reports.

SSC/TSS: Beginning in 2002, the water quality measurement total suspended solids (TSS) was replaced by the parameter suspended sediment concentration (SSC).

Grain Size: In 2008-2012, grain size was analyzed using an optical laser method (reporting % volume) for sand and finer fractions (<2mm). For samples with granule+pebble fractions (measured as % dw), results were scaled to total 100% assuming equal density.

In 2008-2012, grain sizes reported by the optical method may show variable agreement with sieving methods for sand particles due to their relative transparency and smaller subsamples analyzed.

Organic Sums: Organic group sums, for example "Sum of PCBs (SFEI)", are calculated by SFEI based on the target analytes for an analyte group; the exact number and the group constituents may vary over the years.

Metal Data: All metals from 1993 to 2008 are reported as near totals. Beginning in 2009, water and tissue trace metals (Ag, Al, Cd, Cu, Fe, Pb, Mn, Ni, and Zn) are reported as total concentrations. Chemical analyses of sediment samples is generally performed on the <2mm fraction.

MDLs: While every effort is made to obtain the method detection limit (MDL) value from the labs, if none is available, other detection limits may be provided (e.g., instrument detection limit, sample detection limit, reporting limit). However, all detection/reporting limits are stored in the MDL field. Although some MDL values may appear truncated in the cross-tabulated output (e.g., 0.00), full results are provided in the flat file Excel worksheet.

Tissue Reference Sites: Two reference station codes (T-0 and T-1) are included in the tissue results for some years. T-0 indicates that the reference bivalve was analyzed before being deployed. T-1 indicates that the reference bivalve was analyzed after being deployed.

RMP Sampling Strategy: From 1993-2001 RMP sampling sites for water, sediment and bivalve tissue were at fixed locations throughout the Estuary. Starting in 2002 the RMP changed to a random sampling design for both water and sediment. The bivalve sampling sites remain at fixed locations. All sites, whether random or fixed, are associated with an Estuary region.

PCB Sums: Beginning in 2009, the following three PCB Sums are reported:

  • Sum of 40 PCBs - This sum is calculated using the standard 40 PCBs and is reported for all years when available.
  • Sum of 208 PCBs - This sum provides an index of the PCBs present in Aroclor mixtures. The one PCB excluded is PCB 11, which is abundant in some matrices but is derived from pigments (e.g., Hu and Hornbuckle. 2009. Inadvertent Polychlorinated Biphenyls in Commercial Paint Pigments. Environmental Science & Technology, 44 (8), p.2822-2827, Apr 2010) and not Aroclors. PCB 11 does not have dioxin-like potency and has different sources than Aroclors.
  • Sum of 209 PCBs - This sum is provided solely for comparison to other studies that use this statistic. SFEI does not recommend using this sum for comparison to any Aroclor-based thresholds (the TMDL target, OEHHA thresholds, etc.) - the Sum of 208 PCBs is better for that purpose.

Co-eluting PCB and PBDE congeners: During the analytical process, some PCB and PBDE congeners (co-eluting PCBs and PBDEs) cannot be distinguished as separate congeners and thus are quantified as a complex of one or more congeners. When a reportable congener is co-eluting with another congener, we flag this result according to the following rules:

  • If a reportable congener co-elutes with another reportable congener, then the dominant congener (established from the literature) contains a qualifier "DO" and the quantitative result. For example, PCB 056 often co-elutes with PCB 060, and PBDE 008 often co-elutes with PBDE 011. The dominant congeners, PCB 060 and PBDE 008, will have "DO" in the qualifier field and the concentration measured in the result field. PCB 056 and PBDE 011, the non-dominant congeners, will have "DO060" and “DO008” in the qualifier field referring the user to look for the quantitative result in congener PCB 060 and PBDE 008, respectively. The qualifier alerts the user that the result is a mixture of more than 1 congener, and identifying the dominant congener that makes up the highest percent of the mixture.
  • If a reportable congener co-elutes with a non-reportable congener, then the reportable congener has the qualifier "DO" and the quantitative result.

8. How can I view surface model maps?

Surface model maps, similar to the ones included in the Status and Trends section of The Pulse of the Bay reports, can only be generated for RMP sediment and water chemistry data that can be displayed as quartiles. There are two types of surface model maps available in CD3: Surface Model and RMP Pulse Style Surface Model. The RMP Pulse Style maps (1) exclude wet year data for sediment, (2) exclude pre-2002 historical station data, and (3) include only data from the following bay segments: Suisun Bay, San Pablo Bay, Central Bay, South Bay, and Lower South Bay. Individual RMP Pulse Style Surface Models may differ from those depicted in The Pulse of the Bay due to variation in data processing methods.

9. What are HUCs?

A Hydrologic Unit Code (HUC) identifies a watershed within a hierarchical system dividing drainage basins into progressively smaller nested geographic areas. The size of the hydrologic unit decreases as the level of HUC subdivision increases: a HUC8 unit consists of one or more HUC10 units, each of which consists of one or more HUC12 units. In CD3, users can filter results spatially by HUC8, HUC10, and HUC12 boundaries. Visit the USGS website for more information.

10. Why can't my data be displayed as quartiles on the map?

In order for data to be displayed as quartiles, the results must be divided into 4 numeric groupings. In cases where quartiles are not displayed, either there is not a sufficient number of results or range among the values for the selected analyte/unit combination to evaluate as quartiles.

11. How should I cite San Francisco Bay RMP data?

Regional Monitoring Program (RMP) for Water Quality in San Francisco Bay (

12. What is the difference between Conventional analytes displayed under the test material of Basic Water Quality versus Water Chemistry?

Basic Water Quality measurements are taken in the field. Water Chemistry results have been analyzed in a laboratory according to specific analytical methods.

13. What is the difference between the different data download tools?

The Download Mapped Data tool allows you to download the data you have mapped, which is one analyte for a test material. The Direct Download Tool allows you to download data for a project with the options to select all project data, one analyte group and sub-group, or one or more analytes. Both downloads are saved to your computer.

14. What are the art credits for the CD3 Data Download test material buttons?

15. What types of trash monitoring data are available?

Since 2018, SFEI has been collecting data regarding trash that has escaped capture and is found in creeks, rivers, and streams. (These areas are prioritized because trash found there, if not intercepted, will soon be bound for receiving waters.) By working with partner organizations, SFEI has collected data using several different methodologies representing assessments around both the San Francisco Bay Area and Southern California.

16. Why is trash data available separately as a mapped and downloadable data layer?

Trash data relates to water quality by both policy definition and environmental effects. However, the data associated with trash are structured differently from conventional water quality assessments. Therefore, the data are prepared as a separate data layer.

SFEI has made available for download data from its own trash assessment fieldwork, funded by the California Ocean Protection Council, during the 2018 and 2019 field seasons. In addition, SFEI has made available data from its partner organizations. Bay Area Stormwater Management Agencies Association (BASMAA) data, collected to support the development of its regional receiving waters monitoring program, is available for download via CD3. Furthermore, trash assessment data from the Southern California Coastal Water Research Project (SCCWRP) appears in the trash data layer. These data represent methods developed by BASMAA and the Stormwater Monitoring Coalition (SMC).

To download these data please scroll to the bottom of the popup boxes that appear when a trash monitoring point is clicked.

For more information on BASMAA's methods, please see the BASMAA Trash Committee. For information on the methods practiced in Southern California by the Stormwater Monitoring Coalition, please see their organizational website.

17. What are Operational Landscape Units (OLUs)?

To delineate individual OLUs, we first identified three major geomorphic unit types along the shore: (1) headlands and small valleys, (2) alluvial fans and alluvial plains, and (3) wide alluvial valleys. These distinct units are distinguished by different underlying geology and resulting landscape morphometrics, such as slope of the shoreline, the width of the baylands, and watershed size. Once determined, geomorphic units were further divided into individual Baylands OLUs by different methods for each unit type based on topographic and bathymetric considerations in addition to landscape morphology considerations.

For more information and detailed methods on how each geomorphic unit type and Baylands OLU was delineated, see the San Francisco Bay Shoreline Adaptation Atlas (2019) report.