Cal. Gov. Code § 22556

Any public agency on whose behalf the board has made any advances of money as provided in Section 22601 shall reimburse the State in the amount of any such advances, together with interest at the rate of 6 percent per annum from the time of such advance; provided, that there shall be no interest charge in any instance in which the amount of interest, if charged, would be less than one dollar ($1). Such interest when collected shall be paid into the Treasury and credited as revenue to the General Fund.