RCH staff acted as Senior air quality analysts to complete the emission inventories of construction activities and operations, hazardous air pollutants, and greenhouse gases for Chicago O'Hare International Airport Terminal Area Plan Environmental Assessment including aircraft, ground support equipment, motor vehicles, and stationary sources. Development of air quality analysis included processing the data to utilize aircraft delay/queue/taxi information during arrival and departure in dispersion modeling, the use of detailed traffic data, and incorporation of airport data to develop aircraft schedule, operations, and fleet mix.

Air quality analysis was completed using the FAA's AEDT and USEPA's AERMOD dispersion modeling system. Air quality analysis included two alternatives and two future analysis years. Dispersion modeling using nitrogen oxides to nitrogen dioxide conversion methods per USEPA guidelines. A statistical model evaluation was conducted to compare modeled to measured values at a nearby monitoring station to determine the best performing method.