Contaminant Concentrations in Storm Water Entering the Sinclair/Dyes Inlet Subasin of the Puget Sound, USA During Storm Event and Baseflow Conditions

The Sinclair and Dyes Inlet watershed is located on the west side of Puget Sound in Kitsap County, Washington, U.S.A. (Figure 1). Puget Sound Naval Shipyard & Intermediate Maintenance Facility (PSNS&IMF), U.S. Environmental Protection Agency (USEPA), the Washington State Department of Ecology (WA-DOE), Kitsap County, City of Bremerton, City of Bainbridge Island, City of Port Orchard, the Suquamish Tribe, and other stakeholders have joined in a cooperative effort to evaluate water-quality conditions in the Sinclair-Dyes Inlet watershed and correct identified problems. A major focus of this project, known as Project ENVVEST, is to develop Water Quality Improvement Projects (also known as Total Maximum Daily Loads - TMDLs) for constituents listed on the 303(d) list within the Sinclair and Dyes Inlet watershed (Johnston 2004). Segments within this watershed were listed on the State of Washington's 1998 303(d) list due to fecal coliform contamination in surface waters, metals in sediment and fish tissue, and organics in sediment and fish tissue (WA-DOE 2003). Stormwater loading was identified by ENVVEST as one potential source of sediment contamination that lacked sufficient data for the contaminant mass balance calculations conducted for the Sinclair-Dyes Inlet watershed. This paper summarizes the results of contaminant concentrations measured in representative streams and outfalls discharging into Sinclair and Dyes Inlets during 18 storm events and wet/dry baseflow conditions between November 2002 and May 2005. This paper serves as a portion of the report entitled, Surface and Stormwater Quality Assessment for Sinclair and Dyes Inlet, Washington (Brandenberger et al. 2007). Prepared in collaboration with Pacific Northwest National Lab, Sequim, WA and the Environmental Company, Bellevue, WA.