Some facilities submit separate reports for each operation, while others aggregate wastes from all operations in a single report. EDF aggregated multiple, separate facility reports to the TRI and AIRS databases. Facilities have different processes and products. Differences in processes and products create differences in the types and quantities of waste generated. Facilities may have different utilization rates.
Utilization rate is equal to actual crude oil processed divided by refinery capacity.
The normalized performance indicators used in the ranking are based on refinery capacity, not the actual quantity of crude oil processed, a figure that is much harder to obtain. Because idle capacity costs money, however, refineries try to maximize their utilization rate. Standard economic theory argues that because underutilized facilities are more costly to operate, greatly underutilized refineries are likely to close or increase their production level to the industry norm. Thus, operating refineries are unlikely to differ widely in utilization rate from the norm. Facilities are not bound by the same regulations.