scope:

The Administrator may approve either partial or complete state programs. A ''partial'' state program regulates either solely UST systems containing petroleum or solely UST systems containing hazardous substances. If a ''partial'' state program is approved, EPA will administer the remaining part of the program. A ''complete'' state program regulates both petroleum and hazardous substance tanks.

EPA will administer the UST program in Indian country, except where Congress has clearly expressed an intention to grant a state authority to regulate petroleum and hazardous substance USTs in Indian country. In either case, this decision will not impair a state's ability to obtain program approval for petroleum or hazardous substances in non-Indian country in accordance with this part.

Nothing in this subpart precludes a state from:

(i) Adopting or enforcing requirements that are more stringent or more extensive than those required under this part; or

(ii) Operating a program with a greater scope of coverage than that required under this part. Where an approved state program has a greater scope of coverage than required by federal law, the additional coverage is not part of the federally-approved program.