The Board of Certification, with the advice and assistance of the Secretary of Environmental Quality, shall establish grades of certification for water treatment facility operators corresponding to the classification of water treatment facilities. (1969, c. 1059, s. 2; 1973, c. 476, s. 128; 1989, c. 227, s. 3; c. 727, s. 219(9); 1997-443, s. 11A.26; 2015-241, s. 14.30(v).)