Enacts GS 62-133.12A, authorizing the Utilities Commission (Commission) to adopt, implement, modify, or eliminate a rate adjustment mechanism for one or more of the water and wastewater company's rate schedules to track and true-up variations in average per customer usage from levels approved in the general rate case proceeding under GS 62-133. Allows the Commission to adopt a rate adjustment mechanism only upon finding the mechanism is appropriate as specified and is in the public interest.