Monitoring Results presents data from the Status and Trends portion of the 1998 San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP). A list of reports on Pilot and Special Studies, as well as other RMP related activities can be found at the end of this document. These reports provide perspective and insight on important contaminant issues identified by the RMP, and they describe results from projects that took advantage of RMP field operations. For a summary of the conditions of the Estuary see The Pulse . A print copy may also be ordered by contacting the San Francisco Estuary Institute (SFEI). In 1998, the San Francisco Regional Water Quality Control Board (Regional Board) and seventy-three federal, state, and local agencies and companies participated in the RMP as funders and service providers (Table 1.1). Participants also assist in directing the Program through input or participation on the Steering and Technical Review Committees. The RMP’s overall goal is to provide data and interpretation that helps to address certain information needs of the Regional Board. In general, these efforts fall under five major objectives which provide a framework for efforts to respond to more specific management questions. 1. Describe patterns and trends in contaminant concentration and distribution. 2. Describe general sources and loadings of contamination to the Estuary. 3. Measure contaminant effects on selected parts of the Estuary ecosystem. 4. Compare monitoring information to relevant water quality objectives and other guidelines. 5. Synthesize and distribute information from a range of sources to present a more complete picture of the sources, distribution, fates, and effects of contaminants in the Estuary ecosystem.