A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Appendix 2D – Assessment of Impacts on Local Air Quality

Traffic Data Analysis and Identification of Affected Roads

Roads that were predicted to have traffic or alignment characteristics altered significantly due to the scheme implementation were identified according to DMRB criteria. Details of these criteria are presented in detail in Appendix 2A. These roads are termed ‘affected roads’ and form the basis to define the study area for the local air quality assessment.

A total of 662 roads were identified as affected by the Proposed Scheme with likely impacts on local air quality. All roads within 200m of the affected roads were then identified and also included in the model; these are termed additional relevant roads. A total of 1065 road network links were modelled in the current exercise.

Background Data

Air pollutant background concentrations considered in the current assessment were those resulting from emission sources not explicitly modelled in the assessment.

Estimated Annual Mean background concentrations of NO X, NO 2 and PM 10 within the study area have been derived from UK National maps available from the National Air Quality Information Archive (NAQIA) or the Baseline (2008), and Opening (2015) Years. Data are available at a 1 x 1 km spatial resolution.

When using these National maps, the contributions of the various sources explicitly modelled in the assessment are removed from the total background concentrations to derive appropriate background concentrations for the current exercise. In this assessment, the contributions of emissions from Motorways, Trunk Roads, Primary A Roads and Minor Roads have been excluded from total background concentrations as these have been explicitly modelled in the current exercise.

Monitoring Data

Local Authority and National monitoring data for NO2 and PM 10 were analysed for location and type of station, pollutant measured, data capture, validity and values recorded.

Temporal and spatial trends have been analysed and monitored pollutant concentrations compared to the relevant UK Air Quality Strategy (AQS) objectives (DEFRA, 2007).

A twelve month monitoring programme using diffusion tubes was undertaken (August 2008 to July 2009) at selected locations and further extended at additional hot spots for an additional six months (July 2009 to December 2009) to capture NO 2 spatial and temporal trends across the study area. Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-1 A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Where appropriate, diffusion tubes were co-located with continuous monitors in order to enable appropriate bias and seasonal adjustments to be made.

As the Baseline Year is 2008 and the monitoring campaign spanned from August 2008 to December 2009, the monitoring campaign results had to be adjusted to be able to represent the

2008 Annual Mean NO 2 concentrations at each of the locations sampled. This adjustment allowed a comparison to be made between monitoring data and Air Quality Standards or Objectives on Annual Mean terms. Appendix 2C shows the calculation of the bias correction factor(s) undertaken and the annualisation seasonal adjustment factor used.

The results of the monitoring campaign were used for both model verification and indicative purposes. Diffusion tube site locations are shown in Figure 2.4 and described in Table 2D.1.

Table 2D.1 Description of NO 2 Monitoring Sites

Site Site Description Type X Y Number 1 A5 Victoria Road, Derry Roadside 243149 415455 2 Victoria Road (A5) near Dunwood Park Roadside 241527 414022 3 Woodside Road, New Buildings Roadside 241721 413127 4 Duncastle Road, New Buildings Roadside 241518 411883 5 Victoria Road (A5) near Magheramason Roadside 238625 409644 6 Donaghedy Road, Bready Roadside 237672 406864 7 Victoria Road (A5), between Bready and Cloghcor Roadside 237161 405876 Jn of Vine Road and Willow Road, between Bready 8 Roadside 238140 405825 and Cloghcor 9 Leckpatrick Road, Artigarvan Background 237535 401921 10 Barnhill Road, Strabane Roadside 234312 398520 11 Derry Road, Strabane Roadside 234843 398748 12 Melmount Road, Strabane Roadside 233996 396689 13 A5 Great Northern Link, Strabane Roadside 233533 395947 14 Melmount Road (A5), Liggartown Roadside 234401 391978 15 Bells Park Road, Sion Mills Roadside 232853 392890 16 Fyfin Road, Victoria Bridge Roadside 234886 390225 17 Fyfin Road, Near Erganagh Roadside 229710 385883 18 Killeter Road, Castlederg Roadside 226010 384712 19 Drumquin Rad, near Castlederg Roadside 228761 380941 20 North Drumlegagh Road, Byturn Background 233762 380539 21 Letterbin Road, Deer Park Background 234248 382881 22 Mulvin Road (A5), Victoria Bridge Roadside 235522 389745 23 Strabane Road, Newtownstewart Roadside 239893 385914 24 Bettany Road (A5), Newtownstewart Roadside 241316 384910 Castletown Road between Newtownstewart and 25 Roadside 241433 380905 Mountjoy 26 Gortnagarn Road, Mountjoy Roadside 243462 377602 27 Jn of Glenpark Road and Erganagh Road Roadside 245650 377828 28 B48 Gortin Road, Omagh Roadside 245262 373672 29 Campsie Road, Omagh Roadside 245824 372794

Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-2 A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Site Site Description Type X Y Number 30 Crevenagh Road, Omagh Roadside 246035 372309 31 Tamlaght Road, Omagh Roadside 244345 372351 32 Great Northern Road, Omagh Roadside 244158 372956 33 Church Street, Omagh Roadside 244896 372641 34 Clabogan Road, West of Omagh Roadside 239865 367334 35 Doogary Road (A5), South of Omagh Roadside 246446 370257 36 Seskinore Road, South of Omagh Roadside 246821 369285 37 Tattyreagh Road, Tattyreagh Roadside 245799 365135 38 Carvale Road, Fintona Roadside 244921 361716 39 Ecclesville Road, South of Fintona Roadside 244676 360039 40 Aghafad Road, between Fintona and Clogher Roadside 249892 356913 41 Crossowen Road (A4), Augher Roadside 255989 353289 42 Favour Royal Road (A28), Aughnacloy Roadside 264564 353095 43 Moore Street (A28), Aughnacloy Roadside 266453 352354 44 Carnteel Road, Aughnacloy Roadside 267051 352715 Junction of Rehaghy Road and Glencrew Road, 45 Roadside 269254 353122 Aughnacloy 46 Glencrew Road, Aughnacloy Background 269079 352364 47 Caledon Road (A28), Aughnacloy Roadside 269016 350751 48 Lettice Street (A5), Aughnacloy Roadside 266542 350991 49 A4 Anaghill Road, Ballygawley Roadside 262284 356484 50 A4 Dungannon Road, Ballygawley Roadside 264368 358219 Junction of Whitebridge Road and Martray Road, 51 Roadside 262645 359884 North of Ballygawley 52 Omagh Road (A5) (South side of Road), Garvaghy Roadside 257762 359725 53 Moylagh Road, Beragh Roadside 254028 366530 54 Donaghanie Road, South of Omagh Roadside 251611 368497 55 Letterkennry Road, Nixon's Corner Roadside 240992 414554 56 Lonemoor Road, Derry Roadside 242443 416084 57 River Foyle, Derry Roadside 243507 417339 58 Queens Quay, Derry Roadside 243520 417340 59 Limavady Road, Derry Roadside 245860 417891 60 Crescent Link, Derry Roadside 246304 416783 61 Killyclogher Road (A505), Omagh Roadside 249007 373600 62 Church Street (North side of Road), Dungannon Roadside 279785 362411 63 Church Street (South side of Road), Dungannon Roadside 279799 362408 64 Omagh Road (A5) (North side of Road), Garvaghy Roadside 257791 359737 65 A2 Buncrana Road N, Derry Roadside 242797 419390 66 A2 Buncrana Road S, Derry Roadside 243379 419033 67 A2 Strand Road, Derry Roadside 243554 417858 68 A5 Victoria Road, Derry Roadside 243949 416155 69 The Commons N, Strabane Roadside 232518 399266 70 The Commons S, Strabane Roadside 233128 398450 71 Beechwood Grove, Strabane Roadside 232245 397276 72 A5 Derry Road, Strabane Roadside 235209 399440 73 Railway Street, Strabane Roadside 234314 397979 74 Urney Road, Strabane Roadside 233728 397370 75 A5 Great Northern Link, Strabane Roadside 233492 396956 76 B48 Mountjoy Road, Omagh Roadside 245231 373048

Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-3 A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Site Site Description Type X Y Number 77 McConnell Place, Omagh Roadside 245069 372908 78 B4 Campsie Road, Omagh Roadside 245641 372725 79 Corner of Sunningdale, Omagh Roadside 245072 372241 80 A5 Great Northern Road, Omagh Roadside 244740 372317 81 Clanabogan Road, Omagh Roadside 244049 371548 82 Tullybryan Road, Ballygawley Roadside 262570 356847 83 Church Street, Ballygawley Roadside 262559 357765 84 Main Street, Ballygawley Roadside 263073 357667 85 Old Dungannon Road, Ballygawley Roadside 263303 357515 86 Grange Road, Ballygawley Roadside 263054 357239 Co- Armagh Continuous Monitor Roadside 287530 345842 location Co- Derry Continuous Monitor – Dales Corner Roadside 244178 416760 location

In addition to NO 2 monitoring, a campaign was set up for PM 10 data collection using an OSIRIS instrument. The monitoring was undertaken between September 2009 and May 2010 and the results were used to verify / provide adjustment of modelled road side PM 10 contributions. Table

2D.2 presents the location and details of the PM 10 monitoring site. Data were processed to reflect the Annual Mean concentrations for 2008 in line with the relationships observed between the monitoring periods for 2008 and 2009 at the monitoring site and two local background stations.

Table 2D.2 Location and Details of the OSIRIS

Site Distance Z* X Y Site Description Type from kerb Number (m) (m) (m) (m) OSIRIS Adjacent to the A5 just Roadside 2.9 2.5 246320 370665 Monitor south of Omagh *Height above ground

Further details on PM 10 data processing, data quality assurance procedures and adjustment are provided in Appendix 2C.

Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-4 A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Local Air Quality Modelling

The model has been run using a full year of meteorological data for 2008 from Castlederg meteorological station with cloud cover data supplemented from Aldergrove. This station is approximately 15km south-west of Strabane and 22km north-west of Omagh and is considered representative of the meteorological conditions experienced in the vicinity of the Proposed Scheme. Further details on model set up, verification and adjustment procedures followed are provided in Appendix 2C.

Evaluation Criteria

As per guidance, professional judgement was applied by qualified IAQM members within Mouchel Air Quality Team to ascertain the significance of the air quality impacts associated with the Proposed Scheme. Professional judgement was used throughout to provide a range of suitable impact significance categories in accordance with DMRB criteria. These criteria relate to both sensitivity of the receptors affected with reference to pollutant concentration exposure

(environmental value) and magnitude of change in Annual Mean NO 2 and PM 10 concentrations resulting from the Proposed Scheme.

Critical concentrations have been established by reputable organisations for most air pollutants at concentrations of specific relevance to the potential effects on human health. These are summarised in Table 2D.3 for NO 2 and PM 10 . If the receptor was the façade of a residential building, it was assumed that any member of the general public could be present within the building including the elderly, infants or other vulnerable groups. No distinction was made between the sensitivity of dwellings, hospitals, schools, etc.

Table 2D.3 Environmental Value (Sensitivity to Change in Concentration) and Descriptors Adopted for Air Quality

Sensitivity NO 2 PM 10

Above Objective/Limit Value Above Objective/Limit Value Very High (>40 µg/m 3) by more than 2 µg/m 3 (>40 µg/m 3) by more than 1 µg/m 3

Above Objective/Limit Value Above Objective/Limit Value High (>40 µg/m 3) by 2 µg/m 3 (>40 µg/m 3) by 1 µg/m 3

Just Below Objective/Limit Value Medium (36-40 µg/m 3)

Below Objective/Limit Value Low (30-36 µg/m 3)

Negligible Well Below Objective/Limit Value (<30 µg/m 3)

Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-5 A5 Western Transport Corridor Environmental Statement Addendum 718736-3000-R-015 REV A

Table 2D.4 presents the approach used to define the magnitude of air quality impacts associated with the Proposed Scheme.

Table 2D.4 Magnitude of Change in Local Air Quality Concentrations

Actual Change 3 Magnitude of Impact (µg/m )

Annual Mean NO 2 Annual Mean PM 10 Increase/decrease Increase/decrease Major > 4 > 2

Increase/decrease Increase/decrease Moderate > 2 - 4 > 1 - 2

Increase/decrease Increase/decrease Minor > 1 - 2 > 0.5 - 1

Negligible ≤ 1 ≤ 0.5

No Change 0 0

Appendix 2 – Air Quality Assessments of Impacts on Local Air Quality © Mouchel 2011 A.2D-6