Cal. Pub. Res. Code § 3764

(a) A hearing conducted by the director shall adhere to the following:
1. (1) When an order is not issued as an emergency order, within 30 days from the date of the service of the notice of appeal, the director shall provide to the operator notice of the time and place of the hearing. The hearing shall take place within 30 days after the date of the director’s notice. The notice shall inform the operator that the director may extend the date of the hearing for up to 60 days for good cause upon application of the operator or the supervisor.
2. (2) When an order has been issued as an emergency order, within 10 days from the date of the service of the notice of appeal, the director shall provide to the operator notice of the time and place of the hearing. The hearing shall take place within 20 days after the date of the director’s notice. The notice shall inform the operator that the director may extend the date of the hearing for up to 30 days for good cause upon application of the operator or the supervisor.
(b) The director shall conduct the hearing within the district where the majority of the wells that are the subject of the order are located, or the hearing may be conducted at a location outside of that district upon application of the operator. The hearing shall be reported by a stenographic reporter and may, in addition, be electronically recorded by either party.
(c) The notice of hearing shall inform the operator of its right to file a written answer to the charges no later than 10 days before the date of the hearing. The notice also shall inform the operator that it has the right to present oral and documentary evidence at the hearing.
(d) Upon a verified and timely petition of the operator, the director may order the testimony of a witness at the hearing. The petition shall be served upon the director and the other party within five days after the filing of an appeal and shall set forth the name and address of the witness whose testimony is requested, to the extent known; a showing of the materiality of the testimony; and a showing that the witness cannot be compelled to testify absent an order of the director. The supervisor may file an opposition to the petition within five days after the petition is served. The director shall either deny or grant the petition within 10 days after receipt of the petition and receiving any opposition to the petition. Upon granting a petition, the director shall issue a subpoena pursuant to Section 3357 compelling the testimony of the witness at the hearing.
(e) The director may convert a hearing pursuant to this section to a formal hearing conducted in accordance with Chapter 5 (commencing with Section 11500) of Part 1 of Division 3 of Title 2 of the Government Code in any of the following circumstances:
1. (1) The operator makes a showing satisfactory to the director that the order being appealed is likely to result in termination of an established oil or gas producing or injection operation.
2. (2) It appears to the director that the hearing will involve complex evidentiary or procedural issues that will cause more than minimal delay or burdens.
3. (3) The operator and the supervisor agree and stipulate to convert the hearing to a formal hearing.
(f) The conversion of a hearing pursuant to this section to a formal hearing shall be conducted in accordance with Article 15 (commencing with Section 11470.10) of Chapter 4.5 of Part 1 of Division 3 of Title 2 of the Government Code.