(a) In setting rates for a natural gas local distribution company in a general rate case proceeding under G.S. 62-133, the Commission may adopt, implement, modify, or eliminate rate adjustment mechanisms to enable the company to recover the prudently incurred capital investment and associated costs of any of the following, including a return based on the company's then authorized return:
(1) Complying with federal gas pipeline safety requirements.
(2) Producing and transporting natural gas, as defined in G.S. 62-133.4(e)(3), or consistent with the intent and purpose of G.S. 62-133.4.
(b) The Commission shall adopt, implement, modify, or eliminate any of the rate adjustment mechanisms authorized under this section only upon a finding by the Commission that the mechanism is in the public interest.