70 ILCS 2605/4.30
No treasurer, comptroller, paymaster, auditing officer or other officer or agent of the sanitary district shall approve the payment of, or be in any manner concerned in paying any salary or wage to any person for services as an officer or employee in the public service covered by this Act, unless an estimate, payroll or account for such salary or wage, containing the names of the persons to be paid and a statement of the amount to be paid each and the matter on account of which the same is to be paid, shall be filed with him, bearing the certificates of the Director that the persons named in such estimate, payroll or account have been appointed or employed in pursuance of law, and that the amounts of money set forth are lawfully due them under this Act and of the rules made in pursuance of this Act. Before the Director shall certify any estimate, payroll or account for the salary or wage of any person appointed to any new office or new place of employment in the classified service, he shall investigate and determine whether such office or place of employment is in fact new and was properly created, and shall record his findings in that respect before making any certificate as aforesaid.
70 ILCS 2605/4.30