Illinois Administrative Code
Title 83 - PUBLIC UTILITIES
Part 712 - COST ALLOCATION FOR SMALL LOCAL EXCHANGE CARRIERS
Subpart D - COST APPORTIONMENT METHODOLOGY
Section 712.280 - Regulated/Nonregulated Apportionment Bases

Cost pools are defined to be homogenous groups of costs which share a causal relationship. Many cost pools can be directly assigned to either regulated or nonregulated activities. Where a cost pool cannot be directly assigned to either regulated or nonregulated service, a further apportionment is required. Sections 712.285 through 712.375 outline each of these bases and provide a cross-reference to the specific accounts in Subpart E where the method is employed.