Newlands Cross Upgrade EIS - European Investment Bank

South Dublin County Council N7 Newlands Cross Upgrade
Environmental Impact Statement
9.5 Predicted Impact on Air Quality
Arup Consulting Engineers
9.5.1 Construction Year (2009)
9.5.1.1 Construction Traffic
An estimate was made of likely construction traffic flows (see Chapter 5) – for heavy vehicles
only as these will have the greatest impact locally. It was estimated that approximately 400
vehicles two-way (per day), mainly on the N7, would be the worst-case construction traffic
flow.
Predicted concentrations (including background concentrations) for the Do-Minimum and the
Do-Something scenarios for the construction year, 2009 show that all air quality standards are
complied with (refer to Table 9.9).
The receptor showing the greatest increase in levels of pollutants, as a result of the proposed
scheme is Receptor 1 (refer to Figure 9.2). For this receptor, annual average concentrations of
NO2 are predicted to be 32.5 μg/m³, which complies with the AQS of 40 μg/m³; annual average
concentrations of PM10 are predicted to be 18.7 μg/m³, which complies with the existing AQS
of 20 μg/m³ and the proposed AQS of 40 μg/m³; annual average concentrations of PM2.5 are
predicted to be 11.2 μg/m³, which complies with the proposed concentration cap of 25 μg/m³;
annual average concentrations of CO are predicted to be 451.3 μg/m³, which complies with the
LAQM guideline of 2,000 μg/m³ and annual average concentrations of benzene are predicted
to be 2.6 μg/m³, which complies with the AQS of 5 μg/m³.
The increase in concentrations of CO, benzene, NO2 and PM2.5 at Receptor 1 as a result of the
proposed scheme are all less than 1% of the relevant AQS. This is classed as a negligible
impact according the NRA significance criteria (refer to Table 9.2). The increase in
concentration of PM10 as a result of the proposed scheme is less than 5% of the relevant AQS.
This is classed as a slight adverse impact according to the NRA criteria.
Table 9.9 Results of DMRB Modelling of Construction Traffic
Receptor Description Scenario
R1 N7 East
R2
Belgard
Road
R3 N7 West
R4
R113
Fonthill
Road
CO
(µg/m 3 )
Benzene
(µg/m 3 )
NO2
(µg/m 3 )
PM10
(µg/m 3 )
PM2.5
(µg/m 3 )
Air Quality Standards 2000 5 40 20 25
Do Min 442.9 2.53 32.23 18.39 11.03
Do Something 451.28 2.55 32.51 18.66 11.20
Increase/Decrease 8.38 0.02 0.28 0.27 0.162
% Increase/decrease 0.4 0.4 0.7 1.4 0.6
Do Min 446.55 2.51 30.48 18.05 10.83
Do Something 446.56 2.51 30.48 18.05 10.83
Increase/Decrease 0.01 0 0 0 0
% Increase/decrease 0.0 0.0 0.0 0.0 0.0
Do Min 436.51 2.51 31.59 18.17 10.90
Do Something 443.59 2.53 31.91 18.42 11.05
Increase/Decrease 7.08 0.02 0.32 0.25 0.15
% Increase/decrease 0.4 0.4 0.8 1.3 0.6
Do Min 471.19 2.56 32.68 18.83 11.30
Do Something 464.69 2.54 32.51 18.65 11.19
Increase/Decrease -6.5 -0.02 -0.17 -0.18 -0.108
% Increase/decrease -0.3 -0.4 -0.4 -0.9 -0.4
December 2007 Page 149