Evaluation of Lines of Evidence in Support of Establishing Remedy Effectiveness

Battelle/USEPA

Exa collaborated with Battelle to evaluate a research and remediation project for the USEPA’s National Risk Management Research Laboratory (NRMRL) and the Great Lakes National Program Office (GLNPO).  The Lower Ottawa River sediment remediation project included a suite of assessment and monitoring methods along physical, chemical, and biological lines of evidence (LOEs) collected over a ten-year, seven-phase study.  Exa developed a framework to objectively evaluate the monitoring data with the goal to support a clear and transparent weight-of-evidence approach in assessing remedy effectiveness. The team also made recommendations on application of the methods and metrics for other EPA projects.  Exa received a library of historical project documents and electronic data. Tissue, water, sediment, bioassay, and other project data were compiled in a standardized Microsoft Access database.  The Exa team evaluated the statistical relevance, strength, and reliability of each LOE through analysis and visualization of the information. A paradigm was developed where the LOE data could be analyzed relative to site-specific questions, and several potential conceptual site models were developed and compared.  Empirical data were summarized and evaluated individually and collectively for their ability to accurately measure remedy effectiveness.  A Draft Remedy Effectiveness Assessment (REA) report was produced, presenting evidence from the most effective LOEs to assess whether remedial actions achieved project goals.