(a) Each utility shall allow the department staff, upon presentation of identifying credentials, to enter upon, inspect, and examine the records and properties of persons to the extent such records and properties are relevant to determining the compliance of such persons with department rules or orders, or the commission rules or orders.
(b) Each utility shall permit the department to conduct inspections in response to or related to any of the following:
(1) Routine scheduling;
(2) A complaint received from a member of the public or any party;
(3) Information obtained from a previous inspection;
(4) Pipeline accident or incident; and;
(5) Compliance with En 500.
(c) The department shall schedule and conduct inspections if:
(1) Results obtained in an initial inspection show a defect, irregularity or non-compliance which establishes the need for a subsequent or follow-up inspection; or
(2) The department determines that additional inspections are required to provide sufficient information to allow it to determine utility compliance with department rules or orders, or commission rules or orders.