All water treatment plants and water distribution systems required by section 1419 of the federal Safe Drinking Water Act, as amended to January 1, 2000, shall be under the supervision of an operator whose competency is certified by the secretary in a grade corresponding to the classification of the plant or system. Certificates of proper classification shall be issued without examination to the operators of plants and systems not requiring certified operators under § 34A-3-4 before July 1, 2000. The governing body or owner of the water system shall designate such persons in writing to the secretary by January 1, 2001. A certificate so issued is valid only for that operator and that plant or system. The certificate shall be marked, restricted. If the water treatment or distribution system is classified to a higher level, the operator shall meet the initial certification requirements for the system's new classification. An operator issued a restricted certificate pursuant to this section shall comply with all rules promulgated pursuant to § 34A-3-24 , for certificate renewal and training of certified operators. A restricted certificate may be revoked pursuant to §§ 34A-3-21 to 34A-3-23 , inclusive, as provided for in this chapter and the rules promulgated pursuant to §