ABSTRACT
An estimated 1.4 billion gal of used oil are generated each year in the United States alone. Automotive maintenance facilities, do-it-yourself (DIY) oil-changing practices, manufacturing companies, electric-generating stations, and mining and smelter operations are among the primary sources of used oil. Prior to RCRA regulations, a significant portion of used oil was utilized and disposed of improperly; for example, used oil had routinely been applied to control road dust and kill roadside weeds. New regulations, however, have banned certain uses and encouraged others. For example, under RCRA, about 1.9 billion L (500 million gal) of used oil are burned in 30,000 boilers and industrial furnaces (Mouche, 1995). Unfortunately, large quantities of oil continue to be improperly disposed; about 200 million gal are dumped onto the ground, discarded in ordinary household trash, and poured down storm sewers and drains (U.S. EPA, 1994). The persistent components of these oils are transported via sewers and large water bodies where they sink into sediments. Pollution due to used motor oil occurs worldwide and reaches several million tons yearly.
