Note: Modeled using (a) the current run-up areas; (b) the Z1 run-up areas; and (c) the Z2 run-up areas. The large hotspot in the southwest corner of the footprint is from engine testing emissions in a hangar/maintenance area.
Figure 11 shows the three-month average concentration fields at RVS with the engine testing emissions removed for (a) the base-case scenario of using the original run-up areas; (b) the Z1 run-up areas; and (c) the Z2 run-up areas. (Note the contour color scales for Figure 10 and Figure 11 are different.) The NW run-up area had the highest concentrations after engine testing emissions were zeroed out, and the highest modeled concentration in this area was 52 ng/m3 for the base-case scenario. Compared to taxiways and takeoffs (25%, 6%), run-up areas (64%) had a relatively high contribution to the maximum modeled three-month average Pb concentration across the RVS airport footprint.
Concentration fields were also modeled for the counterfactual of all run-up area emissions removed, which would be the best-case scenario; in this case, the maximum concentration near the NW run-up area was 22 ng/m3, a 55% reduction from the base case. When run-up emissions were moved to the Z1 run-up areas, the maximum near the NW run-up area was 36 ng/m3, which is a 30% reduction from the base case and 53% of the maximum possible reduction that would be achieved by completely removing run-up emissions.
When the run-up emissions were moved to the Z2 areas, the maximum around the NW run-up area was 48 ng/m3, which is only an 8% overall reduction and 13% of the maximum possible reduction. One possible explanation for this concentration rebound could be that moving to the Z2 areas moves the NW run-up area closer to other taxiways and their intersections (see Figure 9 for the map of RVS).
Figure 11
Modeled Three-Month Average Concentrations from November-January at RVS with Engine Testing Emissions Removed
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