(C) The department within thirty days of receipt of an application for a permit shall notify, in writing, interested agencies, all adjoining landowners, local government units in which the land is located and other interested persons of the application and shall indicate the nature of the applicant's proposal. Public notice shall be given at least once by advertisement in state and local newspapers of general circulation in the area concerned. The department may hold a public hearing on applications which have any effect on a critical area if it deems a hearing necessary. The public hearing shall be held in the county where the land is located and if in more than one county the department shall determine in which county to hold the hearing or may hold hearings in both counties. Provided, all interested agencies, all adjoining landowners, local government units and other interested persons shall have thirty days to file a written comment to such application after receipt of any such notice by the department.