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Two types of air
quality analysis are being performed in support of the Draft O’Hare
Modernization Environmental Impact Statement (EIS) – emission
inventories and dispersion analysis. The emission inventories provide
an indication of the change in total air pollutant and pollutant
precursor emissions with implementation of the Proposed Project. The
dispersion analysis evaluates both macroscale and microscale effects.
The macroscale analysis provides an indication of the change in
concentrations of carbon monoxide, nitrogen dioxide, sulfur oxides and
particulate matter on and in the vicinity of the Airport while the
microscale analysis evaluates concentrations of carbon monoxide
immediately adjacent to intersections/interchanges within the study
area.
The emission
inventories and the macroscale dispersion analysis were prepared using
the following Federal Aviation Administration (FAA) and US Environmental
Protection Agency (USEPA) computer models which are commercially
available:
The
FAA-required EDMS is a model designed to assess the air quality impacts
of proposed airport development projects. The USEPA’s MOBILE model is a
tool for predicting emissions of hydrocarbons, carbon monoxide, oxides
of nitrogen, carbon dioxide, and particulate matter from cars, trucks,
and motorcycles. The USEPA’s CAL3QHC model is a carbon monoxide model
that includes a traffic model to calculate delays and queues that occur
at signalized intersections. Finally, the USEPA’s NONROAD model is used
to estimate air pollution inventories for nonroad vehicles, equipment,
and engines.
The computer
models are not available on this website. However, links have been
provided where the models may be ordered and/or downloaded. The
computer modeling is being performed by Environmental Science
Associates, one of the Third Party Consultants (TPCs) supporting the FAA
in the preparation of the EIS.
As the draft methodologies, project
files, and modeling results of the air quality analysis become
available, the FAA will post these components. However, please be
advised that the data continues to be reviewed by the FAA and is subject
to change.
If you
have any problems accessing any of the information presented on this
website, please e-mail ompeis@faa.gov |
