This chapter presents an introductory guide for the operation and maintenance of biosolids incineration systems and fundamental aspects related to combustion. For those desiring an in-depth study of biosolids incineration systems, with greater emphasis and coverage of combustion theory, the various texts by Calvin Brunner on this topic are highly recommended. Biosolids combustion, therefore, produces more flaming as volatiles are oxidized than coal. Although the composition of biosolids differs considerably from that of other fuels, the principles of combustion are basically the same. The preceding explanation assumes ideal combustion. Since an ideal combustion or incineration system is only possible on paper, excess air, greater than the ideal stoichiometric combustion requirement, is provided to assure sufficient oxygen when complete combustion is required.