Ill. Admin. Code tit. 83, § 452.40 – Restricted Physical Access

a) Except as necessary under Section 452.50, or as required by an order of a state or federal court or administrative agency, and in addition to the requirements of Section 452.35(a), no merchant generation function employee who provides generation services to Illinois customers shall be permitted physical access to the electric utility's system control center, system communications facilities, computer systems, information systems, data storage, office space, file cabinets, office equipment or any other facilities, equipment or systems used by the transmission and distribution function that differs in any way from the access available to non-affiliated ARES. The requirement of this subsection shall work in conjunction with Section 452.35(a) through physical separation or secured access facilities or mechanisms.
b) Physical access by mandatory generation function employees to the electric utility facilities, equipment or systems described in subsection (a) that differs from the physical access provided by the electric utility to non-affiliated ARES shall be permitted. In no event, however, shall mandatory generation function employees circumvent, or be used or allowed by the electric utility to circumvent, any provision of Section 452.80, 452.90, 452.100, or 452.110 of this Part. The Commission may limit or prohibit such physical access if the Commission, taking into account Section 16-119A(c) and (d) of the Act [220 ILCS 5/16-119A(c) and (d)], determines after hearing upon complaint or on its own motion that:
1. 1) An electric utility has violated any provision of Section 452.80, 452.90, 452.100, or 452.110 of this Part; and
2. 2) Such limited or prohibited physical access would better accomplish the non-discrimination and efficient competition goals of Section 16-119A of the Act [220 ILCS 5/16-119A].
c) Physical access by company leadership or administrative support to the electric utility facilities, equipment or systems described in subsection (a) shall not be restricted. In no event, however, shall company leadership or administrative support circumvent, or be used or allowed by the utility to circumvent, any provision of Section 452.80, 452.90, 452.100, or 452.110 of this Part.