FIGURE 2-7 Schematic representation of the combustion gas flow path through the PFS. The carbon filters, denoted by “C,” are actually horizontal beds with gas flow from the first bed through the second bed and then out through the HEPA filter, denoted by “H.” “F” is a generic denotation for various types of filters. The efficiency of the particulate prefilter is 85 percent. SOURCE: Robie Jackson, Waste Management Manager, ANCDF, and Tracy Smith, Trial Burn Manager, ANCDF, “The use of carbon at ANCDF,” Presentation to the committee, June 5, 2008.