California Code, Health and Safety Code - HSC § 40501

(a) The south coast district board shall appoint a hearing board, or may authorize the board of supervisors of each county included, in whole or in part, within the south coast district to appoint a hearing board in accordance with Article 1 (commencing with Section 40800) of Chapter 8. The hearing board shall have the powers and duties vested in the hearing board of a county district, except as modified in this article. In addition, the hearing board has the same powers and duties with respect to plans for the control of emissions of air contaminants required by a district rule or regulation as it has for permits for authority to construct or operate any article, machine, equipment, or other contrivance required by the south coast district board.

(b) The granting of variances shall be processed by the hearing board in the county in which the variance is applicable unless the applicant and the hearing board agree otherwise, and shall be granted in conformance with the rules and regulations of the south coast district, and, except as modified by this article, with Article 2 (commencing with Section 42350) of Chapter 4 of Part 4, with respect to the granting of variances or the appeal of decisions.