0815415c____Code_of_Federal_Regulations__Requirement
[Deadline] At least 30 days prior to closure. [Requirement] 
(vii) If you plan to close your well, you must notify the UIC Program Director of your intent to close the well (this includes closing your well prior to conversion) Note: This information is requested on national form “Preclosure Notification for Closure of Injection Wells”.
eCFR — Code of Federal Regulations
Requirement