The primary objective of this project is to demonstrate an approach to develop site-specific bioaccumulation models to enable more cost effective risk informed decision-making at Department of Defense (DoD) sites. Bioaccumulation models will be developed using field and laboratory exposures of deposit- and suspension-feeding benthos concurrent with deployment of solid-phase microextraction (SPME) passive samplers. Contaminant concentrations measured in porewater and tissues will be used to derive biota-porewater accumulation factors as well as regression models that can then be applied in probabilistic risk assessments. Further development of site-specific regression models will allow DoD to propose the use of passive samplers in lieu of more expensive tissue analysis of resident infauna and/or bioaccumulation testing for long-term monitoring.
The project will combine multiple lines of evidence building upon methods developed through previous ESTCP and SERDP efforts, including the following technologies:
This project will bridge the gap between the established methods of measuring Cfree and the application of this technology for risk assessment and long-term monitoring. Once established, the site-specific models are expected to provide site managers with a viable alternative to measuring bioaccumulation, providing site managers with more reliable and readily deployable methods for predicting tissue concentrations, while reducing site assessment and long-term monitoring costs, and uncertainty in risk-based cleanup levels. (Anticipated Project Completion - 2024)