The management of contaminated sediment includes a wide range of activities such as dredged material evaluation, initial site assessment and characterization, remediation and restoration activities, annual monitoring, and review of post site cleanup. These programs require a variety of technical disciplines to address complex site exposure pathways and multiple contaminants of concern.
Sediment evaluations are conducted under national and regional guidance, when applicable, and follow guidance detailed in (but not limited to): The Southeast Regional Implementation Manual (SERIM), Evaluation of Dredged Material Proposed for Ocean Disposal – Testing Manual (OTM/Green Book), Evaluation of Dredged Material Proposed for Discharge in Waters of the U.S. – Testing Manual (ITM), The Puget Sound Estuary Program (PSEP), Dredged Material Evaluation and Disposal Procedures – Region 10 (Seattle DMMP User Manual). The Port Gamble laboratory has a strong familiarity with the procedures established in the most recent version of the SERIM through the successful completion of ongoing dredged material evaluations in the southeast regions.
Determining site cleanup based on sediment concentrations without knowing whether the contaminant is truly available or if the test results were skewed due to other non-contaminant factors, could result in extensive, costly, and often ineffective remedial actions.
Our staff focus on understanding the availability and toxicity of sediment-bound contaminants and distinguishing contaminant related effects from other contributing factors (CFs). By reducing uncertainty, risk-based management decisions are more refined and cost-effective. Our scientists have developed strategies and data collection activities focused on quantifying and reducing programmatic uncertainties. The toxicity of a contaminant is not always predicted based on the measured chemical concentration. A chemical’s toxicity is determined by the ‘bioavailable’ fraction of contaminant, which can be influenced by association with different matrices as well as isolation within the sediment.
Examples of Contaminated Sediment Service Areas
- Dredged Material Evaluations (404 Compliance)
- Site Assessment and Characterization
- Remedial Investigations/Feasibility Studies
- Bioaccumulation/Bioavailability Studies
- Toxicity Identification Evaluations
- Contributing Factors Analysis and Interpretation