Within the surfaces detailed in Sections 16.50 - 16.120, the following uses are prohibited:
In determining if an emission or environmental discharge will interfere with the health and safety of pilots and the public, the Division will observe all relevant factors, which include, but are not limited to, the density of discharge, frequency of the emission or discharge, source of the discharge, general weather patterns in the vicinity, time of day, and volume and type of aircraft that use the airport. When a hazard exists, the Division will issue a letter stating mitigation measures that must be complied with within 30 calendar days after issuance of the letter, or within that period of time specified in the letter, to avoid penalties (see Section 16.200).
Ill. Admin. Code tit. 92, § 16.130