Cal. CCP § 1141.18

(a) Arbitrators shall be retired judges, retired court commissioners who were licensed to practice law prior to their appointment as a commissioner, or members of the State Bar, and shall sit individually. A judge may also serve as an arbitrator without compensation. People who are not attorneys may serve as arbitrators upon the stipulation of all parties.

(b) The Judicial Council rules shall provide for the compensation, if any, of arbitrators. Compensation for arbitrators may not be less than one hundred fifty dollars ($150) per case, or one hundred fifty dollars ($150) per day, whichever is greater. A superior court may set a higher level of compensation for that court. Arbitrators may waive compensation in whole or in part. No compensation shall be paid before the filing of the award by the arbitrator, or before the settlement of the case by the parties.

(c) In cases submitted to arbitration under Section 1141.11 or 1141.12, an arbitrator shall be assigned within 30 days from the time of submission to arbitration.

(d) Any party may request the disqualification of the arbitrator selected for his or her case on the grounds and by the procedures specified in Section 170.1 or 170.6. A request for disqualification of an arbitrator on grounds specified in Section 170.6 shall be made within five days of the naming of the arbitrator. An arbitrator shall disqualify himself or herself, upon demand of any party to the arbitration made before the conclusion of the arbitration proceedings on any of the grounds specified in Section 170.1.