The opportunity for innovative thinking prevails at the U.S. Department of Energy's Hanford Site in southeastern Washington state. Two projects, in particular, challenged risk assessment staff. They are: 1. A combined Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)/Resource Conservation and Recovery Act (RCRA) risk assessment 2. Developing a risk assessment for a mixed-waste disposal facility.
The combined CERCLA/RCRA risk assessment involved establishing data quality objectives (DQO) either to meet clean closure for a RCRA treatment, storage and/or disposal facility (TSD) or (if the former was not possible) to conform to goals established for industrial land use for Hanford Past-Practice Strategy (HPPS) sites. Radionuclide analysis was reduced by 60 percent through the DQO process.
Developing a risk assessment for the RCRA TSD facility raised several issues. What is the source of information for the contaminants of concern? What are the scenarios for exposure? How will the short-term and long-term impacts be evaluated?