...
Except as §265.1 provides otherwise:
(a) The owner or operator of a facility which disposes of hazardous waste by underground injection is excluded from the requirements of Subparts G and H of this part.
(b) The requirements of this subpart apply to owners and operators of wells used to dispose of hazardous waste which are classified as Class I under §144.6(a) of this chapter and which are classified as Class IV under §144.6(d) of this chapter.
[Comment: In addition to the requirements of Subparts A through E of this part, the owner or operator of a facility which disposes of hazardous waste by underground injection ultimately must comply with the requirements of §§265.431 through 265.437. These sections are reserved at this time. The Agency will propose regulations that would establish those requirements.]