A waste oil handling apparatus features a tank with draining compartments for receiving waste oil containers in inverted and elevated positions above the tank floor. Multiple drain ports communicate with the tank interior at different elevations relative to the floor for draining accumulated contents of varying density that have gravitationally separated into distinct layers at those elevations. The ports feature adjustable fittings for adjusting the levels from which the layered contents are drawn through the ports from the tank interior. The tank has a large cleanout access by which personnel can access the tank interior for thorough cleanout. The compartments are organized into one or more troughs, each having a pivotal lid thereon. Lift brackets under the floor enable lifted transport of the tank by pallet jack or forklift.