Columbia Departmental Interchange ordinance (Charter § 159)

In accordance with procedure established by the city manager and subject to the city manager's approval, it shall be the duty of the various department directors to furnish to any other department such service, labor, equipment, or materials as may be requisitioned by the head of such other department. The charge for such service, labor, equipment, or materials shall be made to the department so furnished at actual cost or reasonable depreciated value.