Environmental Engineering Reference
In-Depth Information
vehicles, power plants, biogenic sources, etc.). The base case simulation is evaluated
with respect to ambient air quality measurements. If the base case simulation
reproduces concentrations of observed species with reasonable fidelity, then the
model can be used in a future year assessment of Project impacts. The future year
modeling involves development of a future year Project emission inventory as
well as a future year regional emission inventory. Project AQ and AQRV impacts
are determined from the future year PGM simulations.
This paper presents the use of the
Co
mprehensive
A
ir Quality
Mo
del with
E
x
tensions (CAMx) [4] PGM to estimate the potential ozone, AQ, and AQRV
impacts due to a proposed natural gas production project in southwest Wyoming.
We briefly describe the model application and then focus on the CAMx simulation
of winter high ozone events in southwest Wyoming.
2. CAMx Model Configuration
To assess the AQ and AQRV impacts of the proposed oil and gas Project located
in southwest Wyoming, CAMx is applied for both base year and future year
simulations on a 36/12/4 km nested-grid modeling domain. The 36 km grid covers
the continental United States and serves to provide boundary conditions to the
finer grids. The main study area lies within the 12/4 km modeling domain shown
in
Fig. 1.
1500
1000
500
4km
0
12km
-500
-1000
-1500
36km
-2000
-2000
-1500 -1000 -500
0
500 1000 1500 2000 2500
Fig. 1.
36/12/4 km Nested CAMx Modeling Domain
CAMx was applied for the calendar years of 2005 and 2006 using actual
emissions of NOx, SO
2
, PM
10
, PM
2.5
, VOC and CO from all sources for those
years. Detailed emission inventories of oil and gas production sources in the 12/4 km
domain have been compiled for these periods, and a comprehensive regional
emission inventory has been prepared. CAMx output gas and particle phase model
concentrations were compared against observed values for the two modeled base
years.
