California Code, Government Code - GOV § 66622

The members of the commission shall serve at the pleasure of their respective appointing powers.  The members shall serve without compensation, but each of the members shall be reimbursed for necessary expenses incurred in the performance of the member's duties.  However, in lieu of reimbursement for attendance at commission or committee meetings, or at meetings in an official capacity as a commissioner, each member of the commission or alternate who is not a state or federal employee shall receive a per diem of one hundred dollars ($100) per day, not to exceed a combined total of four days in any one calendar month.  No member of the commission who receives a per diem from any other source for attending a meeting shall receive a per diem under this section for attending the same meeting.

A member, subject to confirmation by the member's appointing power, may authorize an alternate for attendance at meetings and voting in the member's absence.  Each alternate shall be designated in a written instrument which shall include evidence of the confirmation by the appointing power and the alternate's name shall be kept on file with the commission.  Each member may change the member's alternate from time to time, with the confirmation of the appointing power, but shall have only one alternate at a time.  Each alternate shall have the same qualifications as are required for the member who appointed the alternate, except that each county representative may designate as an alternate a public official whom the appointing power deems qualified to represent the county.