7 county-level rules, plus city-specific rules for 1 city in Cook County, Illinois.
Verified from official government sources
Helicopter operations over Cook County fall under exclusive FAA jurisdiction under 49 USC 40103, so neither the county noise ordinance nor municipal codes can directly limit helicopter altitude or routes. Complaints route to the FAA Chicago FSDO and O'Hare TRACON.
Cook County Chapter 38 environmental control rules and Illinois Pollution Control Board Title 35 Part 901 set 75 dBA daytime construction equipment limits at residential property lines in unincorporated Cook. Most suburbs adopt parallel municipal noise ordinances with similar daytime caps.
625 ILCS 5/12-602 requires every motor vehicle to maintain a working muffler and bars excessive or unusual noise; Cook County Chapter 38 layers receiving-land dBA limits on idling delivery trucks. Suburbs add their own loading-dock and idling restrictions enforced by local police.
Helicopter flight paths through Cook County airspace are sequenced exclusively by the FAA Chicago TRACON (C90) and O'Hare and Midway towers. State and local governments have no authority to designate or close in-flight rotorcraft routes under 49 USC 40103 federal preemption.
Hospital helipads in unincorporated Cook County require a Chapter 32 building permit plus Illinois Department of Public Health licensure under 77 IAC 250 hospital regulations. EMS helicopter flight noise itself is FAA preempted; only siting, lighting, and structural review are local.
Both O'Hare and Midway are City of Chicago Department of Aviation airports operating under FAA Part 150 noise compatibility programs. Cook County has no county-owned commercial airport and therefore no county-level engine run-up rules; CDA airfield-use procedures govern run-ups.
Cook County Chapter 38 environmental control rules and Illinois Pollution Control Board Part 901 set octave-band sound limits that capture low-frequency bass through 31 Hz and 63 Hz bands. dB(C) measurements supplement dB(A) when complaints describe rumble or thumping bass.
1 cities in Cook County have their own noise from specific sources rules. Each link goes to that city's dedicated page with code citations.
See every category we cover for Cook County — parking, noise, fences, fires, animals, pools, and more.
Cook County Ordinance Hub →