7.(1) Every order under section 3, sub-section (3), shall state the amount of costs incurred under section 3, section 4, sub-section (1), section 4A, sub-section (1), and the cost of preparation of the reference to be made under section 5, sub-section (1), if any, and by what persons and in what proportions they are to be paid, and such costs shall be recoverable as arrears of a public demand. (2) Any person against whom an order has been made with regard to such costs, may, within one month of the date of such order, prefer an appeal to the ¹[Commissioner] in respect of such costs.