(a) The commission shall follow the mandates of the TWC, Chapters 12 and 13, to calculate the annual cost of service. The commission shall rely on any reasonable methodologies set by contract which identify costs of providing service and/or allocate such costs in calculating the cost of service.
(b) When the protested rate was calculated using the cash basis or the utility basis, and the rate which the protested rate supersedes was not based on the same methodology, the commission may calculate cost of service using the superseded methodology unless the seller establishes a reasonable basis for the change in methodologies. Where the protested rate is based in part upon a change in methodologies the seller must show during the evidentiary hearing the calculation of revenue requirements using both the methodology upon which the protested rate is based, and the superseded methodology. When computing revenue requirements using a new methodology, the commission may allow adjustments for past payments.

Source Note: The provisions of this §24.315 adopted to be effective October 17, 2018, 43 TexReg 6826