What USTs are included?
A UST system means a tank or combination of tanks which is, was, or may have been used to contain an accumulation of “regulated substances” as defined in Section 21101(g) of Part 211, and whose volume (including connected underground piping) is ten percent or more beneath the ground. Regulated substance includes petroleum and hazardous substances as defined in the federal Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), 1980 PL 95-510.