(a) The unit operator may propose to modify a unit agreement by submitting an application to BLM that:

(1) Identifies the proposed change and the reason for the change; and

(2) Certifies that all necessary unit interests have agreed to the change.

(b) BLM will send the unit operator written notification of BLM's decision regarding the application. Proposed modifications to a unit agreement will not become effective until BLM approves them. BLM's approval may be made effective retroactively to the date the application was complete. BLM may approve a different effective date, including a date the unit operator requests and for which the unit operator provides acceptable justification.