Chemical health risk assessment for hazardous and mixed waste management units at Lawrence Livermore National Laboratory

The waste characterization for each treatment unit or process is based on treatment records from LLNL's computerized Hazardous Waste Management Inventory System (HWMIS). In 1990, these data were compiled into a single database comprising both hazardous waste and mixed waste data. Even though these data originate from the same source used in the previous HRA, the database was modified to set quantities and concentrations to a consistent set of units. This allowed an analysis of waste types by Hazardous Waste Management unit that was more accurate and did not rely upon many of the conservative assumptions used in the Phase II HRA waste characterization. Finally, the current waste characterizations are considered more representative of potential long-term wastes because they were developed by combining all wastes that could be treated in each unit, as opposed to the wastes treated only during 1988 to 1989. This final step more appropriately accounts for the variability in waste types likely to be seen by the Hazardous Waste Management Division. The quantities of each waste listed in the characterization tables represent the sum of all chemical quantities belonging to hazardous and mixed waste types potentially handled by each area