This sampling and analysis plan (SAP) presents project information along with sampling and analytical methodologies that will be employed to conduct sediment quality monitoring in 2023 as part of King County’s Ambient Marine Monitoring Program. This work is being performed as part of a long term sediment monitoring program designed to assess sediment quality in Elliott Bay. The SAP includes a description of the project, monitoring history, sampling design, sampling and analytical methodologies, quality assurance/quality control, and reporting requirements. The SAP has been prepared in accordance with the Washington State Department of Ecology (Ecology) guidance document Sediment Cleanup User’s Manual (SCUM).