MCU15/0095 Air Quality Assessment

4.8         Summary of Modelling Assumptions
As noted above, several assumptions were adopted for the purposes of estimating emissions from
the service station. Overall, these assumptions represent a conservative approach and are consistent
with recommendations made by overseas regulatory authorities. The assumptions adopted are as
follows:

⚫ all fuel handling is considered to be petrol providing a conservative emissions generation
    procedure (i.e., petrol has a higher volatility than diesel);

⚫ a minimum efflux velocity was adopted for the vent stack emissions of 0.1 m.s -1. This allows
    modelling of these as point sources;

⚫ to ensure worst case meteorological conditions are considered, it is assumed that bulk tanker
    deliveries occur continuously throughout the year (day and night);

⚫ for tank filling, a fuel delivery of 40,000 L/hour for the E10 tank has been considered;
⚫ all fugitive emissions were assumed to occur in the working area of the service station (i.e. a
    rectangular volume source located around the petrol bowsers) below the roofed area;

⚫ an average filling and transaction time of 4 minutes per vehicle;
⚫ an average 40 L of fuel per vehicle refuelling.
⚫ worst case CAPCOA “whoosh” emissions adopted to represent slightly higher volatility of
    Australian fuels.

⚫ A factor of 1.20 has been applied to the emission rate to account for E10 fuel sold (20% of E10
    fuel sold compared to other fuel types based on proposed tank volumes and a factor of 1.5 for
    the E10 proportion only).


4.9         Modelling Results
Tables 4.2 and 4.3 presents the predicted maximum concentrations at the subject site. Figures 4.2
and 4.3 present the pollutant concentration contours for odour and benzene (cumulative) in the
modelled area.

Table 4.2: Predicted VOC Results – Maximum Predicted Concentrations at Modelled Sensitive
Receptors

                                Maximum Predicted
                          Concentrations at Modelled                                   Air Quality Goal
    Compound                                                                                                             Averaging Time
                          Sensitive Receptors (g/m3)                                          (g/m3)
                          Source Only                      Cumulative

      Benzene                0.07                                3.0                                10                             Annual

       Toluene                  19                              44.7                               958                          30 Minutes




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                            Synergy Property Partners Pty Ltd- Air Quality Assessment - Proposed Service Station, 123 Eumundi-Noosa Road, Noosaville
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