A compactor for compacting and dewatering debris comprises a housing having an inlet for enabling debris to be delivered to forwarding augers which forward the debris to a compaction chamber at the discharge end of the housing. The chamber has an outlet opening of less cross-sectional area than that of the chamber, thereby ensuring compaction of the debris as it moves toward discharge. Debris enroute to discharge may be sprayed with water to remove sludge-like substances which otherwise would cling to some types of debris.