Every community water supply operator certified by the Agency shall be capable of performing his or her duties without endangering the health and well being of the populace; shall be able to read and write English; and shall produce evidence acceptable to the Agency as to his or her character and his or her ability to maintain and operate properly the structures and equipment entrusted to the operator’s care. In addition, water supply operators shall be certified as Class “A”, Class “B”, Class “C”, Class “D” operators in accordance with classes based on the level of competency determined by examination and in accordance with educational and experience levels as follows:
     (a) Class “A” and Class “B” Water Supply Operator Certificates require graduation from high school or equivalent and not less than 3 years of acceptable study, training, and responsible experience in water supply operation or management as described in Sections 13 and 14 of this Act.
     (b)  Class “C” Water Supply Operator Certificates require graduation from high school or the equivalent and not less than one year of acceptable study, training, and responsible experience in water supply operation or management as described in Sections 13 and 14 of this Act.
     (c)  Class “D” Water Supply Operator Certificates require graduation from high school or equivalent and not less than 6 months of acceptable study, training, and responsible experience in water supply operation or management as described in Sections 13 and 14 of this Act.
     (d) The requirement for graduation from high school or the equivalent shall be waived for community water supply operators certified prior to the effective date of this amendatory Act of the 91st General Assembly and for community water supply operators certified under Section 19(a) of this Act.