Within 30 days following the date of receipt by the commission of the petition to declare lands unsuitable for surface mining or to modify or terminate the designation, the commission shall determine the completeness and validity of the petition and notify the petitioner of the results of such determination. If the petition is found to be complete and valid, it shall be kept on file by the commission and made available for public inspection. If the petition is rejected, the notice of rejection shall set forth each of the reasons for rejection. The determination to accept or reject the petition shall be published in the Texas Register.