Newlands Cross Upgrade EIS - European Investment Bank

South Dublin County Council N7 Newlands Cross Upgrade
Environmental Impact Statement
9.3 Assessment Methodology
Arup Consulting Engineers
9.3.1 Baseline Air Quality Monitoring
A survey of baseline ambient air quality at the proposed site was carried out by Bord na Móna
Technical Services using the methodologies outlined below.
9.3.1.1 PM10
Airborne PM10 was monitored using a portable Ruprecht & Patashnick, Mini Partisol Model
air sampler. This sampler draws a measured volume of air through a chamber containing
preconditioned and pre-weighed filters meeting the US EPA protocol for PM10 sampling.
Monitoring was carried out over 24 hour periods at a single location (refer to Figure 9.1).
9.3.1.2 NO2 and SO2
NO2 and SO2 levels in the air were determined using diffusion tubes. This procedure takes gas
samples by diffusion of the component of interest through a membrane layer. Analysis was
carried out by UV Spectrophotometry. Monitoring was carried out at five locations (refer to
Figure 9.1)
9.3.1.3 VOCs
Background levels of VOCs were determined using diffusion tubes. Benzene, toluene, ethyl
benzene and xylene were specifically targeted. The diffusion tubes were placed on stands, in
well ventilated areas away from trees and fences and situated approximately 1-2m above
ground level. Monitoring was carried out at five locations (refer to Figure 9.1)
9.3.2 DMRB Screening Assessment
The Design Manual for Roads and Bridges (DMRB) Screening Method was used to assess the
impact on air quality associated with roads at grade for the construction year (2009), the
opening year (2010) and the design year (2025).
The most recent air quality assessment methodology is included in the May 2007 revision of
the DMRB. This revision includes the DMRB Screening Method (Version 1.03b) 9 spreadsheet
used in this assessment. This spreadsheet calculates annual average concentrations of NO2,
PM10, CO and benzene.
The DMRB requires the following input data:
• Location and distance of sensitive receptors to road (Figure 9.2);
• Annual average daily traffic flow (AADT, Appendix A9.1);
• Average speeds (refer to Appendix A9.1);
• Traffic composition (% HGV, refer to Appendix A9.1);
• Road type; and
• Background concentrations.
Representative receptors were identified based on their sensitivity (e.g. school, hospital or
house) and proximity to the roads affected by the proposed scheme (refer to Figure 9.2).
Annual average concentrations for the traffic related pollutants NO2, PM10, CO and benzene
were modelled at each receptor. The Do-Minimum (without the proposed scheme) and Do-
Something (with the proposed scheme) were modelled for the construction year, 2009, the
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