The interaction between microbial heat output (at the expense of the waste being treated) and temperature was identified as the fundamental factor in controlling the composting process. The concept was implemented by means of a temperature feedback control system in conjunction with forced pressure ventilation. Field trials involved raw sewage sludge mixed with woodchips, on a scale of up to 20-ton piles. The new process, which is presently available technology, is called the 'Rutgers static pile composting process'. Some of its advantages are as follows: A starting moisture content of 75 percent is decreased to 25 percent in 12 days; This tendency to dry represents the decomposition of putrescible (odor-causing) organic matter; No condensate is produced; The need for a curing stage can be assessed in terms of specific, objective criteria; The process is operationally flexible to meet the vagaries of environmental regulation; The drying tendency might be exploited in the preparation of biomass-derived fuel.