(1) The owner or operator shall maintain records in accordance with ARM 17.56.305 that are capable of demonstrating compliance with closure requirements under this subchapter. Results of the excavation zone assessment required in ARM 17.56.703 must be maintained for at least three years after completion of permanent closure or change in service in one of the following ways:

(a) by the owners and operators who took the UST system out of service;

(b) by the current owners and operators of the UST system site; or

(c) by mailing these records to the department if the records cannot be maintained at the closed facility.