430 ILCS 35/6

If it shall appear from examination, inspection or evidence that any of the provisions of this Act and the rules and regulations adopted pursuant thereto are being violated, the Department may cause notice of such violations to be given to such violator in writing at least 10 days prior to the date set for hearing. Such notice may be served by delivery thereof personally to such violator, or by mailing it by certified mail to such violator at his last known address. At the time and place fixed in the notice, the Department shall proceed to hearing on the charges and such violator shall be accorded ample opportunity to present in person or by counsel, such statements, testimony, evidence and argument as may be pertinent to the charges or to any defense thereto.