Measurement and Modeling of Ecosystem Risk and Recovery for In Situ Treatment of Contaminated Sediments
Abstract
The project [ER 1552] addresses strategies to assess the ecological recovery after in-situ sediment treatment by activated carbon (AC) amendment at Hunters Point, San Francisco Bay, California. Rapid assessment tools to measure polychlorinated biphenyls (PCBs) sediment pore water concentrations were tested to correlate aqueous concentrations of PCBs with reduced bioavailability. Polyethylene sampling devices (PEDs) and a PCB immunoassay technique were compared and the polyethylene results correlated with those obtained using conventional methods. Further work with thin polyoxymethylene (POM) sampling devices demonstrated the utility of this method to measure the vertical pore water profile in the sediment and how this compares to the AC distribution in sediment cores. A heat and mass transfer model using field temperature profile data was developed to estimate pore water movement in the intertidal mudflat sediment with AC. Three regional surveys determined the benthic species recruitment pool from 30 reference sites and PCB-induced changes at Hunters Point by means of functional ecology comparisons. A biodynamic modeling approach was developed to predict the uptake of PCBs by benthic invertebrates with different feeding strategies. Field-related influences on bioaccumulation and the effectiveness of AC-amendment were tested with in-situ bioassays and passive sampler deployment. Finally, the biodynamic model was used to simulate PCB exposure scenarios present at Hunters Point and the reference sites. Though PCB tissue concentrations are expected to remain slightly higher at Hunters Point than at the reference sites, the model suggests that the expected remedial success with AC-amendment would comply with the clean-up goal for Hunters Point and sediment quality guidelines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2011
- Accession Number
- ADA545470
Entities
People
- Janet K. Thompson
- Richard G Luthy
- Samuel N. Luoma