The US Energy Information Administration (EIA) recently published an article describing an increase in the energy content of municipal solid waste (MSW). The reason for this increase is an increase in the percentage of waste from "non-biogenic" sources (i.e. plastics) as compared to biogenic sources (paper, cardboard, wood, food and yard waste, etc.) Biogenic waste has an average heat content of 11 MMBtu/ton, as compared to 23 MMBtu/ton for non-biogenic waste.