Any county, city, or township or portion of a county, city, or township may withdraw from a vector control district whenever a petition signed by the governing body of the county, city, or township or at least twenty percent of the residents of the county, city, or township, or portion thereof, desiring to withdraw from the district, is approved by the department. Prior to approving a petition to withdraw from the district, the department shall fix a time and place for a public hearing on the petition. The place of the hearing must be convenient and accessible for a majority of the residents of the district. At least ten days prior to the date of the hearing, the department shall publish a notice of the hearing in at least one newspaper of general circulation in the district. Prior to the hearing the department shall investigate the petition to withdraw. If the department finds that it is not feasible, desirable, or practical to allow the petitioning entity to withdraw from the district, it shall make an order denying the petition and state the reasons for its action. If the department finds that the petitioning entity is no longer benefited by being included within the boundaries of the district or if other reasons make the withdrawal of the petitioning entity desirable, proper, and necessary, it shall grant the petition and modify the boundaries of the district. No person may be a member of the board of commissioners if that person is no longer a resident of the vector control district after the boundaries have been modified. A new member must be appointed to replace any such member in the manner provided for original appointments.