Editors' Summary: There are an estimated 300,000 leaking underground storage tanks (USTs) in the United States today. These tanks are believed to be a leading cause of groundwater pollution. To address this situation, Congress enacted Subtitle I of the RCRA, Regulation of Underground Storage Tanks. Subtitle I, and the regulations promulgated by EPA, address aspects of UST use from notification of tank existence to performance standards for new tanks to corrective action and tank closure. The author examines each aspect of the UST program, focusing on which tanks are regulated, who is responsible for them, and what substances they contain. The author examines the program's emphasis on state responsibility for detailed regulation and its adoption of total quality management techniques to foster creativity. The author concludes with observations on using the UST program as a model for other federal programs.