Enacts new GS 62133(c1), authorizing water or wastewater public utilities to use a fully projected future test period in lieu of the test period provided in subsection (c). Directs the Utilities Commission (Commission), when using a fully projected future test period, to determine the projected rate base at the end of the future test period. Directs the Commission to adopt rules and regulations regarding submission requirements for fully projected future test periods. Directs a public utility that uses a fully projected future test period as part of a final rate determination by the Commission to provide appropriate data evidencing the accuracy of the estimates, and authorizes the Commission to adjust the public utility's rates on the basis of that data after notice and hearing. Directs the Commission to permit facilities projected to be in service during the fully projected future test period to be included in the base rate.