The inspection fee shall be assessed annually

The operator may, within thirty days after the assessment is mailed, file written objections with the commission stating the grounds upon which it claims that the assessment is not reasonable. The commission shall within thirty days of receiving such objections hold a hearing and issue an order in accordance with its findings as to the proper amount to be assessed to the operator. The order shall be appealable pursuant to chapter 1-26 . If an operator does not pay, or object to, the fee within thirty days after the assessment is mailed, the commission may impose a delinquency fee of ten percent of the inspection fee and interest at the rate of fifteen percent per year on the portion of the fee not paid. Fees collected under this section shall be deposited in the pipeline safety account established in §