This is the phase where the boiler fuel is separated. Light, combustible pieces of refuse, called refuse-derived fuel (or RDF) are separated out using an air knife and whisked to a pneumatic tube, and blown into a large storage bin located midway between the Resource Recovery Plant and the electric utility. Heavier, non-combustible pieces fall through a chute onto a conveyor, eventually to be landfilled.
In terms of tonnage, the RDF accounts for about 70% of the total mass flow of garbage. This fraction, along with the 5% of non-ferrous and ferrous metals recovered, means that 75% or more of the garbage entering the system is recovered in one form or another.