Contaminant Mass Balance for Sinclair and Dyes Inlets, Puget Sound, WA
Abstract
Sinclair Inlet and Dyes Inlets have historically received contaminates from military installations, industrial activities, municipal outfalls, and other nonpoint sources. For the purpose of determining a "total maximum daily load" (TMDL) of contaminants for the Inlets, a contaminant mass balance for the sediments is being developed. Sediment cores and traps were collected from depositional areas of the Inlets and surface sediment grabs were collected from fluvial deposits associated with major drainage areas into the Inlets. All sediment samples were screened using X-Ray fluorescence (XRF) for metals, and immunoassay for PAHs and PCBs. A subset of split-samples was analyzed using inductively coupled mass spectrometry (ICP/MS) for metals and gas chromatography mass spectrometry (GC/MS) for phthalates and PAHs, and GC electron capture detector (GC/ECD) for PCBs. Sediment cores were age-dated using radionuclides to determine the sedimentation rate and the history of sediment contamination. Streams and storm water outfalls were sampled in both the wet and dry seasons to assess loading from the watershed. Seawater samples collected from the marine waters of the Inlets and boundary passages to central Puget Sound were used to estimate the exchange of contaminates with central Puget Sound. The historical trends from the cores indicate that contamination was at a maximum in the mid 1900s and decreased significantly by the late 1990s. The thickness of the contaminated sediment is in the range of 15 to 45 cm. The initial drafting of the mass balance model for copper indicates that approximately 4,000 Kg/yr enters the Inlets and 64% of this loading is from the leaching of boat and ship hulls. The removal of copper from the Inlets is primarily a function of sedimentation (68%) and seawater advection into Central Puget Sound (32%).
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2003
- Accession Number
- ADA529336
Entities
People
- Eric Crecelius
- Jill Brandenberger
- Jim Leather
- Joel Guerrero
- Martin L Miller
- Robert K. Johnston
Organizations
- Naval Information Warfare Systems Command