CRC Report No. A-34 - Coordinating Research Council

April 2005
• Receptor locations
• Source characterization
o Tunnel study
o Gasoline samples
o CNG and LPG samples
o Surface coatings
o Background air samples
• Additional monitoring data
o Tenax samples for heavy hydrocarbons (> C12)
ENVIRON provided information on receptor locations, a tunnel study, gasoline samples, CNG
and LPG samples (although these profiles had not been utilized in the experiments) and
background air composition. Data on surface coatings were not provided because very limited
data are available and DRI was already using data from the same source as ENVIRON.
Providing data for heavy hydrocarbons was beyond the scope of the available source profile data.
Description of Receptor Locations
The receptors were identified by the city/area where they are located. Receptors were sited to be
regionally representative, meaning at least a 25 km 2 area. The receptor locations for A-34 are
not the same as monitoring locations that may happen to have the same name in the real world.
The expected emissions distribution for each area is:
• Anaheim and Van Nuys are densely populated mixed-use residential/commercial/light
industrial areas.
• Hawthorn, Long Beach and LAX are similar to Anaheim and Van Nuys, but in addition
have more heavy industry including petrochemicals (refining and chemical production).
• Diamond Bar is less densely populated than the sites described above and has a diverse
mix of sources.
• Crestline and Lake Perris are downwind sites with low population density nearby.
Crestline is in a forested area that is used for recreation.
Source Characterization
We conducted a virtual tunnel study in the Van Nuys tunnel. Air concentrations for the 55
PAMS species are reported in Table 2-14 for the 9 runs. The virtual tunnel study was based on
data from an actual Van Nuys tunnel study described in Table 2-15. Tables 2-14 and 2-15 were
provided to DRI.
The methodology for the virtual Tunnel study was as follows:
1. The fraction of vehicles older than 20 years was used as a proxy for the fraction of noncatalyst
vehicles.
2. Set the g/mi hot stabilized exhaust emission rate for non-catalyst light-duty vehicles to 8
times that of catalyst vehicles (steps 1 and 2 combined give about 50% emissions from
12% non-catalyst vehicles with variation between tunnel runs).
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