California Code, Public Resources Code - PRC § 6224

The commission may adopt rules and regulations which provide for the payment of either a penalty or interest, or both, by any person who fails to pay the commission any sum when it is due under a lease or agreement. The rules and regulations may provide for the assessment, nonassessment, or waiver by the commission of the penalty or interest, or both. Penalties assessed by the commission shall not exceed 5 percent of the principal sum due and the rate of interest shall not exceed 1 1/2 percent per month from the date on which the sum became due and payable until the date of payment. Penalties and interest assessed pursuant to this section shall be payable to the commission.