Municipal sludge is a high-volume waste. Typical volumes for raw primary sludge range from 2,950 to 3,530 gallons per million gallons of wastewater treated. Volumes for trickling filter humus range from 530 to 750 gallons per million, while the volumes for activated sludge are much higher, from 14,600 to 19,400 gallons per million. It is possible to calculate the quantities of sludge theoretically, but the EPA recommends that treatment operations use pilot plant equipment to make these calculations whenever possible.
