Certificates of proper classification may be issued without examination to a person or persons certified by the owner of the water system to have been in charge of the water treatment plant or distribution system on June 25, 1980. Such certificate shall be valid for a period of 2 years from June 25, 1980, only for that water treatment plant or distribution system. This certificate may thereafter be renewed annually. Applications under this section shall be submitted not later than 90 days before June 25, 1980.