ABSTRACT
An estimated 1.3 billion gallons of used oil is generated each year in the United States alone (USGS 2013). 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 Resource Conservation and Recovery Act (RCRA) regulations, a signicant portion of used oil was used and disposed 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 is burned in 30,000 boilers and industrial furnaces (Mouche 1995). Unfortunately, large quantities of oil continue to be improperly disposed; about 200 million gallons is dumped onto the land, discarded in ordinary household trash, and poured down storm sewers and drains (U.S. EPA 2012). 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.
