A few household hazardous waste programs are beginning to collect used animal and vegetable oils for biodiesel generation. Most of these programs are only available for a few days following major holidays like Thanksgiving. Local governments that sponsor cooking oil collection programs often advertise them in their utiltiy bills and local newspaper. Contact your city or town government offices to see if this service is offered in your area.
If a collection program is not available, household cooking oil can be treated to make it safer for landfill disposal. Landfills are not allowed to accept liquid wastes, so animal or vegetable oil should be solidified by mixing it with kitty litter or other absorbent to the point that the absorbent is moist, but not dripping. The moist absorbent should be double-bagged in trash bags and can then be put in the trash.
These procedures are intended for small quantities of cooking oils from a household only. If you have a large quantity of animal or vegetable oil, check your phone directory for rendering plants or other recyclers.