IL SB0636

Amends the Illinois Aeronautics Act to change the runway limit at O'Hare International Airport from 8 runways to 10 runways, requiring certificate of approval only when a new runway's geographical orientation varies from east-west by more than 10 degrees or when construction would exceed 10 total runways.

Replaces "Ldn" (day-night average sound level) with "annual CNEL" (community noise equivalent level) throughout the Permanent Noise Monitoring Act as the standard noise measurement metric for airport noise monitoring reports.

Adds detailed definitions for annual CNEL, daily CNEL, noise exposure level, and noise level to the Permanent Noise Monitoring Act with specific formulas and technical standards.

Requires noise contour maps in airport monitoring reports to distinguish three time periods: 7:00 a.m. through 6:59 p.m., 7:00 p.m. through 9:59 p.m., and 10:00 p.m. through 6:59 a.m., using annual CNEL measurements instead of Ldn.

Transfers responsibility for preparing permanent noise monitoring reports from the Division of Aeronautics to airport sponsors beginning in 2009, with reports due semi-annually on June 30th and December 31st.