Cal. Gov. Code § 22556

A public agency on whose behalf the board has made advances of money pursuant to Section 22601 shall reimburse the state the amount of the advances, with interest at the rate of 7 percent per annum from the time of the advance, unless the amount of interest, if charged, would be less than one dollar ($1). The interest when collected shall be paid into the Treasury and credited as revenue to the General Fund.