415 ILCS 45/13

Community Water Supply Operators shall be certified in accordance with the following classifications: (a) A "Class A" Water Supply Operator Certificate shall be issued to those individuals who, in accordance with this Act, demonstrate the skills, knowledge, ability, and judgment that are necessary to operate a Class A community water supply in a manner that will provide safe, potable water for human consumption, as well as the skills, knowledge, ability, and judgment necessary to operate Class B, Class C, and Class D community water supplies in a manner that will provide safe, potable water for human consumption. (b) A "Class B" Water Supply Operator Certificate shall be issued to those individuals who, in accordance with this Act, demonstrate the skills, knowledge, ability, and judgment that are necessary to operate a Class B community water supply in a manner that will provide safe, potable water for human consumption, as well as the skills, knowledge, ability, and judgment necessary to operate Class C and Class D community water supplies in a manner that will provide safe, potable water for human consumption. (c) A "Class C" Water Supply Operator Certificate shall be issued to those individuals who, in accordance with this Act, demonstrate the skills, knowledge, ability, and judgment that are necessary to operate a Class C community water supply in a manner that will provide safe, potable water for human consumption, as well as the skills, knowledge, ability, and judgment necessary to operate a Class D community water supply in a manner that will provide safe, potable water for human consumption. (d) A "Class D" Water Supply Operator Certificate shall be issued to those individuals who, in accordance with this Act, demonstrate the skills, knowledge, ability, and judgment that are necessary to operate a Class D community water supply in a manner that will provide safe, potable water for human consumption.