Measurement and Modeling of Ecosystem Risk and Recovery for In Situ Treatment of Contaminated Sediments
ER-1552
Objective
Deployment of PEDs and indigenous benthic community sampling activities at Hunters Point.
Many Department of Defense (DoD) sites are contaminated with polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH), which are persistent, bioaccumulative, and toxic. In conjunction with efforts to remediate these contaminants in situ, there is a need to monitor ecosystem health before and after treatment to assess the efficacy of treatment and ensure that the remediation activity does not harm the native ecosystem. Conventional ecosystem health determinants, such as benthic organism bioassays and community surveys, are time-consuming and expensive. No fast, inexpensive field methods to predict bio-uptake of contaminants and explain post-treatment ecological effects currently exist.
This project will develop a comprehensive strategy to assess the ecological recovery of a contaminated site after in situ treatment. The main objectives of this strategy are to incorporate rapid, inexpensive assessment tools to measure contaminant concentrations in the sediment pore water, to use a biodynamic modeling approach to predict contaminant burden at the base of the food web, and to develop a general model to predict the ecological characteristics of recovery. These objectives are tied together in that biodynamic modeling predictions of contaminant uptake, which depend on contaminant pore water concentrations measured with the rapid assessment tools, are employed in the general ecosystem recovery model. Using this comprehensive strategy, researchers will assess ecological recovery at Hunters Point Naval Shipyard Parcel F (San Francisco Bay) after in situ remediation by activated carbon amendment.
Technical Approach
Two rapid assessment tools will be used to measure PCB sediment pore water concentrations: polyethylene devices (PED) and a PCB immunoassay. The tools will be tested in the laboratory and validated in the field, and the results will be correlated with those obtained using conventional methods. Once correlated, the rapid, cost-effective measurement tools will allow for greater data resolution while monitoring ecosystem recovery. The measured sediment pore water PCB concentrations also will serve as inputs to a biodynamic model, which will be used to predict contaminant uptake by native benthic organisms. This approach uses measured uptake, elimination, and metabolism rates as a basis for predictive modeling under a variety of conditions. Building on the biodynamic modeling for individual species, a general model will be constructed to predict the ecological characteristics of recovery at a contaminated site post-treatment. In contrast to the conventional benthic community survey method, this modeling approach requires only basic information about taxa-specific biodynamics, which needs to be established only once for each species, combined with data on the species available for community recruitment.
Benefits
Establishing correlations between conventional and alternative measurement tools in the field will allow members of the scientific community and DoD users to confidently use the rapid, inexpensive tools in the future to assess the ecological recovery of a contaminated sediment site after treatment or during a monitored natural recovery. Biodynamic modeling will result in a general predictive ecosystem recovery model that is directly applicable to any contaminated sediment site, given some knowledge of the species inhabiting the local community and basic information about taxa-specific biodynamics for the contaminants of interest. Ideally, future researchers and DoD users will need only to measure contaminant pore water concentrations and collect information concerning the benthic organism recruitment pool to predict the extent of ecosystem recovery following remediation. (Anticipated Project Completion – 2013)
Project Documents
Points of Contact
Principal Investigator
Dr. Richard Luthy
Stanford University
Phone: 650-721-2615
Fax: 650-725-8662
Project Documents
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.