An image forming apparatus includes a waste toner system that collects waste toner in a waste toner container. An amount of waste toner collected in the container is increased by using a driven toner distributing member that distributes accumulated toner within the container. The waste toner system may detect the accumulation of waste toner by monitoring a drive control circuit while the toner distributing member is being driven. For example, the system may detect excess accumulation by comparing the monitored values of a frequency control signal with one or more reference values corresponding to nominal accumulation conditions. An extension may be employed whereby movement of the toner distributing member creates interference between the toner distributing member and the container when the toner distributing member reaches a predetermined position. The interference may be detectable from the drive control circuit as an indication of a full condition.