This Part shall apply to all public utilities as defined in Section 3-105 of the Public Utilities Act (Act) [220 ILCS 5/3-105] and to those telecommunications carriers as defined in Sec­tion 13-202 of the Act [220 ILCS 5/13-202] that are subject to the requirements of Section 9-201 of the Act [220 ILCS 5/9-201] and 83 Ill. Adm. Code 285. As used in this Part, the term "utilities" shall include both public utilities and those telecommunications carriers to which this Part is applicable.