70 ILCS 910/11
Every District so established shall be governed by a board of 9 directors appointed in districts wholly contained within a single county by the presiding officer of the county board with the advice and consent of the county board. If the district is located in more than one county, the number of directors who are residents of a county shall be in proportion, as nearly as practicable, to the number of residents of the district who reside in that county in relation to the total population of the district. A director appointed initially in a new district shall be a resident of whichever county is entitled to representation in order to bring about the proportional representation required herein, and he shall be appointed by the county board of that county, or in the case of a home rule county as defined by Article VII, Section 6 of the Constitution of 1970, the chief executive officer of that county, with the advice and consent of the county board.
Upon expiration of the term of a director who is in office on the effective date of this amendatory Act, the successor shall be a resident of whichever county is entitled to such representation in order to bring about the proportional representation required herein, and he shall be appointed by the county board of that county, or in the case of a home rule county as defined by Article VII, Section 6 of the Constitution of 1970, the chief executive officer of that county, with the advice and consent of the county board.
Thereafter, each director shall be succeeded by a resident of the same county who shall be appointed by the same appointing authority; however, the provisions of the preceding paragraph shall apply to the appointment of the successor to each director who is in office at the time of the publication of each decennial Federal census of population.
Each director should be selected because of his particular interest in the field of public health. The appropriate appointing authority in its selection of directors shall give due consideration to a fair representation throughout the District. A director must reside within the territory of the District. Should any director cease to so reside, then his office shall be deemed vacated, and shall be filled by appointment for the remainder of the term as hereinafter provided.
All initial appointments of directors shall be made within 60 days after the determination of the result of the election. Each appointment shall be in writing and filed and made a matter of record in the office of the county clerk wherein the organization proceedings are filed. A director shall qualify within 10 days after appointment by acceptance and the taking of the constitutional oath of office, both to be in writing and similarly filed for record in the office of the county clerk. In the appointment of the first board of directors of such District, the appropriate appointing authority shall appoint 3 members to serve for terms of one year, 3 for terms of 2 years and 3 for terms of 3 years. All members appointed thereafter shall be appointed for terms of 3 years except where an appointment is made to fill a vacancy in which case the appointment shall be for the remaining term of the position vacant. A director shall continue to serve after the expiration of his term until his successor has been appointed and qualified.
70 ILCS 910/11