74 5.6 Annual Average Nitrogen Dioxide Dispersion Modelling Results for Other Locations in the City of Manchester

5.6 Annual average nitrogen dioxide dispersion modelling results for other locations in the city of Manchester

In 2001 Manchester City Council completed the (Phase One), Stage Three Review & Assessment of Air Quality. Based on the results of this Review & Assessment, an Air Quality Management Area, (AQMA), was declared.

The AQMA was based on predicted 2005 exceedences of the annual average nitrogen dioxide objective. The entire area north of the city centre was included in the AQMA, as were significant areas of the south of the city. The AQMA is shown in Section 1, Map 1.2 of this report.

Nitrogen dioxide concentrations have been measured in Manchester, using diffusion tubes since 1986. Bias adjusted diffusion tube results are available from 1997.

The concentration of nitrogen dioxide, measured at roadside locations is currently above the objective. However, roadside concentrations measured across the city show a downward trend, and if this trend continues, the concentration at roadside locations will have reduced to approximately the objective, or below the objective level, by 2005. The downward trend at roadside sites is due to the increasing use of vehicle emission control technology, and does not take into account the reductions that will be achieved by the additional local air quality actions being planned.

The concentration of nitrogen dioxide, measured using diffusion tubes at urban background locations is currently below the objective. The majority of the city will achieve the air quality objectives by 2005.

Areas of predicted exceedence of the 2005 annual average objective are confined to locations close to busy roads and junctions.

The roadside areas of exceedence do include some residential areas, and so public exposure is relevant in these locations.

The results from the Detailed Assessment will be used to inform the Manchester Air Quality Action Plan.

74 5.6 Annual average nitrogen dioxide dispersion modelling results for other locations in the city of Manchester

The assessments of nitrogen dioxide concentrations carried out in sections 5.2 to 5.6 of this report, have dealt with the predicted areas of exceedence that can be expected in Manchester city centre, and in the vicinity of Manchester Airport. Section 5.6 will provide a Detailed Assessment of nitrogen dioxide concentrations across the rest of the Manchester City Council area.

Figure 5.2 and figure 5.3, showed the city of Manchester, and the location of the city centre, airport, and a number of selected districts within the city. Figure 5.3, showing selected districts in the city, is reproduced on the next page.

To the north of the city centre lie the districts of Cheetham Hill, Blackley, and Newton Heath. These districts are characterised by dense terraced housing, dating from the Victorian era and early twentieth century. Within north Manchester there are a number of high-rise mid twentieth century public housing developments.

To the east of Manchester city centre lie the districts of Clayton and Gorton. This area is also typified by dense, terraced housing. However, unlike north Manchester, east Manchester is also home to areas of manufacturing industry. There are a number of large industrial sites in this area, most of which are involved with the chemical manufacturing industry. Some former industrial sites have closed in east Manchester, and there are a number of areas of currently unused land. Many of the former industrial sites in east Manchester are now undergoing redevelopment. The City of Manchester Arena, (used in the 2002 Commonwealth Games), and the velodrome cycling arena, have been built on former industrial sites in east Manchester. Modern houses and apartment blocks are increasingly appearing in amongst the east Manchester development areas.

To the south of Manchester city centre lie the inner city districts of Moss Side, Whalley Range, and Hulme. These districts are typified by dense terraced housing, and mid twentieth century public housing schemes.

Further south, lie the districts of Chorlton-cum-Hardy and Didsbury. These areas are typified by low density semi detached and detached housing. The bars and restaurants in these prosperous districts attract many visitors, and there are consequently heavy traffic flows on roads in these districts.

South of Didsbury lie the outer suburbs of Wythenshawe and Northenden. These areas are characterised by large estates of low density public housing.

75 Figure 5.3 Map showing selected districts in Manchester, and the location of the city centre and airport.

76 Further south still lie the outer suburbs of Wythenshawe, Northenden, and Baguley. These outer suburbs are mainly comprised of inter-war public housing schemes, and are typified by large estates of low density terraced and semi-detached housing.

To the south beyond Wythenshawe lies Manchester Airport, and the beginnings of a rural zone that extends south into Cheshire. Away from the airport, the main industry in this area is agriculture, and the limited residential land use is mainly comprised of isolated, detached houses.

Running through these various areas are a number of large, multi carriageway feeder roads, that radiate out from Manchester city centre, in all directions. In addition to the radial roads, the city centre is ringed by inner and outer multi carriageway ring roads. On the outskirts of the city lies the M60 orbital motorway, which encircles much of Greater Manchester. A selection of main roads in the city are shown in figure 5.19 overleaf.

77 Figure 5.19 Map of selected major roads in Manchester.

M60 motorway

M60 motorway A664 A665 A663

A6010 Outer Ring Road A62 A662

Inner Ring Road A635

A6010 Outer Ring Road A57

A5103 A34 A5145

M60 motorway

A560 M60 motorway A5103

M56 motorway

The M56 motorway which passes Manchester Airport in the south of the city, is downgraded to an ‘A’ road, and becomes the A5103 as it passes through Wythenshawe, north towards the city centre. Some parts of the A6010 outer ring road, and the M60 orbital motorway pass out of the Manchester City Council area, and so these roads are not shown in their entirety on the map.

Monitoring of nitrogen dioxide is carried out at a number of locations in Manchester. Measurements using chemiluminescent continuous analysers are confined to the city centre, and the Manchester South AURN site near Manchester Airport. Results from these analysers were discussed in sections 5.2 and 5.4 of this report. However, nitrogen dioxide diffusion tubes are used to monitor nitrogen dioxide at a variety of locations. The results from the Manchester diffusion tube network are shown in figure 5.20 overleaf.

78 Figure 5.20 Bias adjusted diffusion tube results from Manchester

CIBA Clayton Cheetham Oldham Ashton Site Speciality Day Hill Road Road Old Road Chemicals Nursery Newton Cheetham Openshaw District Heath Clayton Clayton (east Hill (north-east Manchester) Manchester) Site Urban Urban Roadside Roadside Roadside Classification Background Background 1997 - - 42 36 - 1998 - - 32 28 - 1999 47 53 34 31 43 2000 42 44 34 29 37 2001 34 45 38 33 39 2002 28 31 33 31 25 2003 34 37 36 36 31 2005 32 35 34 34 29 All results in ug/m 3

Figure 5.20 (continued) Bias adjusted diffusion tube results from Manchester

Burnage Wilmslow Woodhouse Junction 4 St Pauls Site Community Road Lane M56 School Centre Rusholme Burnage (inner city, District (south-east Wythenshawe Wythenshawe Wythenshawe south of city Manchester) centre) Site Urban Urban Roadside Roadside Roadside Classification Background Background 1997 - 33 - 52 47 1998 - 24 - 49 35 1999 - 26 - 57 37 2000 - 26 - 59 37 2001 - 30 - 59 36 2002 - 29 - 49 34 2003 40 34 34 59 42 2005 38 33 32 56 40 All results in ug/m 3

The results show that roadside concentrations have decreased over time. This trend was also observed in the city centre. Urban background concentrations do not show such a clear trend.

The decreasing trend at roadside locations is due to the impact of the increasing use of vehicle emission control technology. As older and more polluting vehicles are retired, and are replaced with modern low emission cars, the average emission per vehicle kilometre will reduce over time.

79 The projected results indicate that urban background locations will be at or below the objective by 2005. However, the results also indicate that some roadside locations may exceed the objective in 2005.

There are locations across the city where houses have been built with their facades opening directly onto the street. Such houses can be thought of as locations where public exposure would occur at roadside locations. As the projected roadside concentrations exceeded the objective, it was realised that widespread dispersion modelling would be required, in order to accurately define the locations where exceedences were likely.

The Manchester City Council Update & Screening Assessment identified a number of locations where the objective may not be achieved, and which were recommended for inclusion in the Detailed Assessment. These locations were the junctions of;

A664 Rochdale Road and A6104 Victoria Avenue. A576 Middleton Road and Crumpsall Lane. A664 Rochdale Road and Moston Lane. A664 Rochdale Road and Harpurhey Road. A664 Rochdale Road and Collyhurst Road. A663 Broadway and Nuthurst Road. A57 Hyde Road and B6167 Reddish Lane. A62 Oldham Road and B6393 Thorp Road. A6010 Queens Road and Collyhurst Road. A576 Middleton Road and A665 Bury Old Road. A576 Middleton Road and A6044 Sheepfoot Lane. A665 Cheetham Hill Road and Woodlands Road. A665 Cheetham Hill Road and B6180 Waterloo Road. A5103 Princess Road and Platt Lane. A5103 Princess Road and A6010 Wilbraham Road.

Careful attention was paid to ensure that these locations were included in the dispersion modelling work undertaken for the Detailed Assessment. The intelligent gridding facility was also used to maximise model resolution in the vicinity of these junctions.

The results of the dispersion modelling are shown on the contour plots on the following pages. Each contour plot is numbered as a separate modelling area. The location of each numbered modelling area is shown on figure 5.1 of this report.

Figure 5.1 is reproduced on the next page.

80 Figure 5.1 Location of modelling areas.

88 The contour plots shown on the previous pages show that exceedences are predicted for roadside locations close to major roads and motorways in the city. Urban background locations are shown as achieving the objectives. The largest areas of exceedence are shown at locations close to the motorway.

In addition to the contour plots, results were obtained for a number of receptor points in the city. The results obtained at these receptor points are shown in figure 5.21 below.

Figure 5.21 Results from dispersion modelling at receptor points in Manchester city centre

Description of Distance to 2005 NO X 2005 NO 2 Location Location concentration concentration Road (ug/m 3) (ug/m 3) Higher Blakely Exposure location 81m to youth centre close to motorway junction 21 of 102.54 48.25 (near M60 motorway) Residential Residential properties properties at 10m to A663, facing onto roadside location 47m to M60 125.46 47.41 A663 motorway Broadway Residential Residential properties on properties close 42m to 108.12 48.32 Greenwood to motorway junction 3 M56 Road St Pauls RC School location 100m to 70.47 37.58 High School close to motorway junction 4 M56 Residential Residential properties on properties close 40m to 114.63 52.34 Bleasdale to motorway junction 5 M56 Road Residential Urban properties in background in 223m to M60 61.60 31.69 Charlestown north of city Clayton (major 117m to Ciba Speciality industrial site in Ashton New 61.36 31.83 Chemicals Plc East Manchester) Road Burnage Urban 30m to Community background in 53.78 28.71 Burnage Lane Centre south of city Whalley Range SW of the A5103 10m to A6010, High School for - A6010 junction 100m to 56.64 30.13 Girls A5103

The receptor points also indicate that exceedences will be confined to near roadside locations. The urban background sites selected did not show any exceedences of the objectives.

89 Figure 5.22 below shows the roads in Manchester, along which the exceedences have been predicted to occur.

Figure 5.22 Map showing the location of predicted roadside exceedences of the 2005 annual average objective

A576 M60 motorway A664 A665 A663

A6010 Outer Ring Road A62 Briscoe Lane

A662 City Centre A635 A57

A5145 A6 A5103

A34

M60 motorway

Southmoor Road A5103

Junction Hollyedge & Brownley Rd

M56 motorway

Junction of Simonsway & Brownley Rd Junction of Simonsway & Poundswick Ln

The roads and junctions shown in figure 5.22 have different sized areas of exceedence associated with them. The details of the size of the individual areas of exceedence are shown in figure 5.23 overleaf. Traffic characteristics for each of the roads are also shown.

90 Figure 5.23 Extent of areas of exceedence (2005), associated with roads in Manchester, from atmospheric dispersion modelling

Distance of 2005 Traffic flow Buses / HGV boundary of area of on road (annual Road name as percentage exceedence, from average daily of traffic flow centre of road (m) traffic) M60 motorway 101 77177 11 junctions 18 to 20 A576 Middleton 60 38785 4 Road A665 Cheetham 35 11847 9 Hill Road A664 Rochdale 27 22591 6 Road A663 Broadway 17 19138 9

A62 Oldham Road 49 29325 6

Briscoe Lane 27 13863 5

A662 Ashton New 26 20516 3 Road A635 Ashton Old 37 26529 7 Road A57 Hyde Road 48 18009 9

A6 Stockport Road 27 18761 3

B5093 Wilmslow 15 18442 10 Road A34 Kingsway 25 33531 2

A5103 Princess 42 77501 3 Road A5145 Barlow 20 24214 2 Moor Road M60 junctions 2 to 117 107913 9 5 (south of city) A560 Altrincham 29 18761 6 Road M56 107 129108 8 Southmoor Road 20 18604 6

Junction of Simonsway & Poundswick Lane 12 18604 2 Junction of Simonsway & Brownley Road 14 17468 5 Junction of Brownley Road & Hollyedge road 14 19192 3

91 The Detailed Assessment also focussed on the predicted concentrations at the 15 key road junctions identified in the Update & Screening Assessment.

Figure 5.24 Extent of areas of exceedence (2005), associated with selected road junctions in Manchester, from atmospheric dispersion modelling

Distance of 2005 Traffic flow Buses / HGV boundary of area of on road (annual Road name as percentage exceedence, from average daily of traffic flow centre of road (m) traffic) Junction of A664 Rochdale Rd & A6104 30 36083 1 Victoria Ave Junction of A576 Middleton Rd & 30 31252 13 Crumpsall Ln Junction of A664 Rochdale Rd & Moston 43 28423 3 Lane Junction of A664 Rochdale Rd & 45 26801 5 Harpurhey Rd Junction of A664 Rochdale Rd & 21 20895 5 Collyhurst Rde Junction of A663 Broadway & Nuthurst 33 26087 2 Road Junction of A57 Hyde Rd & B6167 Reddish 55 44625 2 Lane Junction of A62 Oldham Rd & B6393 42 34466 2 Thorp Rd Junction of A6010 Queens Rd & 32 23286 11 Collyhurst Rd Junction of A576 Middleton Rd & A665 65 50472 3 Bury Old Rd Junction of A576 Middleton Rd & A6044 45 37788 3 Sheepfoot Ln Junction of A665 Cheetham Hill Rd & 45 24705 7 Woodlands Rd Junction of A665 Cheetham Hill Rd & 48 30154 9 B6180 Waterloo Rd Junction of A5103 Princess Rd & Platt Ln 46 54836 5 Junction of A5103 Princess Rd & A6010 100 67074 6 Wilbraham Rd

92 The results in figures 5.23 and 5.24 indicate that exceedences can be expected near roads and junctions with a predicted 2005 daily traffic flow of 17,000 and over. In addition, exceedences are predicted for roads with an exceptionally high flow of buses or HGVs, (the average bus and HGV proportion on roads in Manchester is 3%). Roads with a bus / HGV flow of 5% or higher have shown exceedences in this modelling. The contribution of emissions from buses and HGVs were assessed in the Manchester City Council Stage 4 Review & Assessment, which identified that buses and HGVs make up 15% and 56% of road transport derived NO X emissions respectively, (10% and 39% of total NO X emissions respectively).

The receptor point results indicated that the maximum annual average concentration, at a point where exposure could occur, (which occurred at residential locations close to the M56 motorway), was predicted to be 52.34 3 3 ug/m , 12.34 ug above the objective. A NO X reduction of 11.15 ug/m would be required to achieve a 12.34 ug reduction in nitrogen dioxide concentration.

The results of this Detailed Assessment indicate that exceedences of the annual average objective will be expected at roadside locations, along the major road network, across the city. These areas of exceedence include residential locations where public exposure is an issue. Urban background sites, (which represent the majority of the city), are not expected to experience exceedences, and the majority of Manchester residents will not be exposed to annual average concentrations of nitrogen dioxide above the objective.

The downward trend in roadside nitrogen dioxide concentrations, which has been observed across the city, indicates that these areas of exceedence will reduce in both size and magnitude. However, Manchester City Council is committed to achieving the air quality objectives, and the city council will introduce a package of measures to improve air quality across the city.

The results of this Detailed Assessment will be used to inform the Manchester Air Quality Action Plan. It is clear from the results that emissions from road traffic are the major source of nitrogen dioxide in the city. All of the areas of exceedence are roadside locations. The Manchester Action Plan will therefore include measures to reduce emissions of NO X across the city, but will focus upon measures to reduce emissions from road vehicles, in the identified areas of exceedence.

93 5.7 2010 nitrogen dioxide dispersion modelling results for other locations in the city of Manchester

Section 5.6 of this report concluded that there were certain roadside locations in Manchester, where the annual average nitrogen dioxide concentration may be exceeded in 2005.

Monitoring of nitrogen dioxide, at roadside locations, has shown that roadside concentrations are decreasing. Guidance issued by DEFRA indicates that this reduction is likely to continue to the year 2010, and beyond.

Atmospheric dispersion modelling has shown that the areas of predicted exceedence in Manchester will reduce in size, between 2005 and 2010. This reduction in the area of exceedence will be achieved by improving vehicle emission control technologies, which have been introduced at a national level.

Despite the predicted reductions in roadside nitrogen dioxide concentration, some roadside areas of the city will still experience exceedences of the objectives in 2010.

94 5.7 2010 nitrogen dioxide dispersion modelling results for other locations in the city of Manchester

In 1999 the European Union introduced the First Air Quality Daughter Directive, (1DD), which set objectives for a number of key air pollutants. The 1DD objectives for nitrogen dioxide match the UK 2005 objectives, (in terms of target concentrations and numbers of permitted exceedences), but are set with a target date of 2010. These 1DD objectives have been transposed into UK legislation.

The EU First Daughter Directive objectives are;

• 1 hour limit of 200 ug/m 3, not to be exceeded more than 18 times per year, to be achieved by 1 January 2010.

• Annual average limit concentration of 40 ug/m 3, to be achieved by 1 January 2010.

An assessment of nitrogen dioxide concentrations against the 2010 1-hour objective was carried out in section 3 of this report. This assessment concluded that there were no locations in Manchester where the 1-hour objective would be exceeded.

The assessment of 2005 annual average concentrations shown in section 5.6 indicated that there were a number of roadside locations in the city where exceedences might occur. All background locations in the city were expected to achieve the objective.

Technical guidance note LAQM TG(03) section 6.06 states that roadside concentrations of nitrogen dioxide are expected to decline, up to and beyond the year 2010. The roadside concentrations measured in Manchester have shown a declining trend. The following section contains a Detailed Assessment of annual average nitrogen dioxide, for the year 2010.

Nitrogen dioxide concentrations, measured in 2003, were projected forward to 2010 using the methodology shown in Technical Guidance Note LAQM TG(03) Box 6.6 and 6.7. The results of this projection are shown in figure 5.25.

95 Figure 5.25 Bias adjusted diffusion tube results from Manchester

CIBA Clayton Cheetham Oldham Ashton Site Speciality Day Hill Road Road Old Road Chemicals Nursery Newton Cheetham Openshaw District Heath Clayton Clayton (east Hill (north-east Manchester) Manchester) Site Urban Urban Roadside Roadside Roadside Classification Background Background 2003 34 37 36 36 31 2005 32 35 34 34 29 2010 27 29 30 30 24 All results in ug/m 3

Figure 5.25 (continued) Bias adjusted diffusion tube results from Manchester

Burnage Wilmslow Woodhouse Junction 4 St Pauls Site Community Road Lane M56 School Centre Rusholme Burnage (inner city, District (south-east Wythenshawe Wythenshawe Wythenshawe south of city Manchester) centre) Site Urban Urban Roadside Roadside Roadside Classification Background Background 2003 40 34 34 59 42 2005 38 33 32 56 40 2010 31 28 27 46 35 All results in ug/m 3

The projected 2010 nitrogen dioxide concentrations shown in table 5.25 indicate that the objective will be met at most background and roadside locations. However, an exceedence was still predicted for the motorway roadside site.

Atmospheric dispersion modelling was repeated for 2010, in order to determine the magnitude and extent of the exceedences for that year. The same dispersion modelling methodology was used as for the 2005 modelling, with only traffic flow and vehicle emission factors being changed for the model inputs.

The results of the dispersion modelling are shown on the following pages. Each contour plot is numbered, and these numbers correspond to the modelling areas shown in figure 5.1.

100

101

102

103 The contour plots on the previous pages show that in 2010 exceedences are still predicted for some roadside locations close to major roads and motorways, but that these exceedences are smaller in geographic extent than those predicted for 2005.

Urban background locations continue to show no exceedences of the objectives.

The total area of predicted exceedence has reduced in size from approximately 8.81 km 2 in the modelling for 2005, to approximately 5.46 km 2 in 2010, (or approximately 62% of the exceedence area for 2005). These areas include locations in the city centre and around the airport.

In addition to the contour plots, results were obtained for a number of receptor points in the city. The results obtained at these receptor points are shown in figure 5.26 overleaf. The receptor points allowed a more accurate assessment to be made of concentrations, when compared to the concentration bandings shown in the contour plots.

104 Figure 5.26 Results from dispersion modelling at receptor points in Manchester

Description of Distance to 2005 NOx 2005 NO 2 Location Location concentration concentration Road (ug/m 3) (ug/m 3) Higher Blakely Exposure location 81m to youth centre close to motorway junction 21 of 102.54 48.25 (near M60 motorway) Residential Residential properties properties at 10m to A663, facing onto roadside location 47m to M60 125.46 47.41 A663 motorway Broadway Residential Residential properties on properties close 42m to 108.12 48.32 Greenwood to motorway junction 3 M56 Road St Pauls RC School location 100m to 70.47 37.58 High School close to motorway junction 4 M56 Residential Residential properties on properties close 40m to 114.63 52.34 Bleasdale to motorway junction 5 M56 Road Residential Urban properties in background in 223m to M60 61.60 31.69 Charlestown north of city Clayton (major 117m to Ciba Speciality industrial site in Ashton New 61.36 31.83 Chemicals Plc East Manchester) Road Burnage Urban 30m to Community background in 53.78 28.71 Burnage Lane Centre south of city Whalley Range SW of the A5103 10m to A6010, High School for - A6010 junction 100m to 56.64 30.13 Girls A5103

The receptor points also indicate that exceedences will be confined to near roadside locations. The urban background sites selected did not show any exceedences of the objectives.

105 Figure 5.22 below shows the roads in Manchester, along which the exceedences have been predicted to occur.

Figure 5.22 Map showing the location of predicted roadside exceedences of the 2005 annual average objective

A576 M60 motorway A664 A665 A663

A6010 Outer Ring Road A62 Briscoe Lane

A662 City Centre A635 A57

A5145 A6 A5103

A34

M60 motorway

Southmoor Road A5103

Junction Hollyedge & Brownley Rd

M56 motorway

Junction of Simonsway & Brownley Rd Junction of Simonsway & Poundswick Ln

The Detailed Assessment also focused on the predicted concentrations at the 15 key road junctions identified in the Update & Screening Assessment.

106 Figure 5.24 Extent of areas of exceedence (2005), associated with selected road junctions in Manchester, from atmospheric dispersion modelling

107 The results in figures 5.23 and 5.24 indicate that exceedences can be expected near roads and junctions with a predicted 2005 daily traffic flow of 17,000 and over. In addition, exceedences are predicted for roads with an exceptionally high flow of buses or HGVs, (the average bus and HGV proportion on roads in Manchester is 3%). Roads with a bus / HGV flow of 5% or higher have shown exceedences in this modelling. The contribution of emissions from buses and HGVs were assessed in the Manchester City Council Stage 4 Review & Assessment, which identified that buses and HGVs make up 15% and 56% of road transport derived NO X emissions respectively, (10% and 39% of total NO X emissions respectively).

108 5.8 Conclusions to the Detailed Assessment of nitrogen dioxide

Phase One of the Local Air Quality Management programme identified locations where the nitrogen dioxide objectives may not be achieved. An AQMA was declared in Manchester in July 2001, based on predicted areas of exceedence of the annual average nitrogen dioxide objective.

The Phase Two Update & Screening Assessment, completed in 2003, identified a number of locations at risk of exceedenig the objectives. These locations were included in the Detailed Assessment.

Monitoring of nitrogen dioxide revealed that background concentrations in the city centre were currently at, or just above the annual average objective. Background locations outside the city centre were shown to have annual average concentrations below the objective. Exceedences of the objective were shown at roadside locations. Roadside concentrations showed a steady downward trend.

Results from the monitoring network were projected to 2005. The projected concentrations showed that the objective would be achieved at background locations across the city, including the city centre. Despite the steady reductions in roadside concentrations, some roadside locations still showed predicted exceedences in 2005.

No locations in Manchester were shown to be at risk of suffering an exceedence of the 1-hour objective.

Atmospheric dispersion modelling of nitrogen dioxide was carried out. The dispersion modelling showed that exceedences of the 2005 annual average can be expected at roadside locations, and within the site boundary at Manchester Airport. Some of the roadside areas of exceedence included locations where exposure was possible. The exceedence area at the airport did not include any locations where public exposure was likely.

The results from this Detailed Assessment will be used to inform the Manchester Air Quality Action Plan. Manchester City Council is committed to achieving the objectives, and will continue to work in partnership with other stakeholders to improve air quality across the city, and to achieve reductions in the areas of exceedence.

109 5.8 Conclusions to the Detailed Assessment of nitrogen dioxide

The Government has adopted both a long term annual average objective, and a short term 1 hour objective, for nitrogen dioxide.

In July 2001, Manchester City Council declared an Air Quality Management Area, based on the results of dispersion modelling, which indicated that some areas of the city were at risk of experiencing annual average nitrogen dioxide concentrations above the objective level. No locations were identified as being at risk of suffering an exceedence of the 1-hour objective, at that time.

The Manchester City Council Update & Screening Assessment indicated that a number of locations in Manchester were at risk of experiencing exceedences of both the 1 hour, and annual average objectives. These locations were selected for inclusion in the Detailed Assessment.

Section 4 of this report provided the results of the Detailed Assessment against the 1-hour air quality objective. The Assessment concluded that there were no locations in Manchester at risk of suffering an exceedence of the 1- hour objective.

Section 5 of this report comprised the Detailed Assessment of nitrogen dioxide against the annual average air quality objective. The Detailed Assessment included a review of the results from nitrogen dioxide monitoring, undertaken across the city.

Results from the Manchester City Council monitoring network indicate that the annual average objective is currently met, at background locations outside Manchester City centre. At background locations within the city centre, the annual average concentration of nitrogen dioxide is currently at, or slightly above, the objective. There was no identifiable trend in the concentrations of nitrogen dioxide measured at background locations.

At roadside locations, both within the city centre, and across the rest of the city, annual average nitrogen dioxide concentrations are currently above the objective. The historical data set of roadside monitoring results indicated that there was a downward trend in roadside nitrogen dioxide concentrations. Government guidance indicates that these reductions in roadside concentration are the result of the increasing use of road vehicle emissions control technology. The reduction in emissions from road vehicles will not only secure reductions in the concentration of nitrogen dioxide at roadside locations, but are also expected to deliver reductions in concentrations at background locations.

Results from the monitoring network were projected forward to 2005, using correction factors supplied in Government technical guidance documents. The projected results indicated that all background locations would achieve the objectives by 2005. However, the projected data also indicated there would be exceedences at roadside locations in 2005. The areas of roadside exceedence included residential areas, where the public may be exposed.

110 Atmospheric dispersion modelling was carried out for annual average concentrations of nitrogen dioxide in 2005. The dispersion modelling also indicated that there would be no exceedences at background locations. A number of roads were identified, where roadside exceedences could occur. The results of the dispersion modelling were used to determine the magnitude, and geographic extent of the predicted areas of exceedence.

Air quality monitoring, and dispersion modelling was also carried out for the area around Manchester Airport. The monitoring was carried out at locations representative of where the public may be exposed. The monitoring indicated that annual average concentrations at these locations were well below the objective level. Dispersion modelling carried out around the airport indicated that exceedences would occur, at locations within the airport boundary, such as the runways and taxiways, and aircraft parking areas. These areas were not thought relevant to non-occupational public exposure.

The results from the dispersion modelling led to the conclusion that exceedences would occur close to roads in the city centre with a daily traffic flow of 13,000 vehicles or more, or where the traffic flow was comprised of more than 10 % of buses and HGVs. Outside the city centre, exceedences were found along roads with a daily traffic flow of more than 17,000 vehicles, or where the traffic flow was comprised of more than 5 % of buses and HGVs.

The results from this Detailed Assessment will be used to inform and target the Manchester Air Quality Action Plan. This plan will comprise a package of measures, designed to lower concentrations of nitrogen dioxide across the city generally, and particularly in those areas identified as being at risk of suffering exceedences of the objectives.

Manchester City Council will also consider reviewing the boundaries of the Air Quality Management Area, in light of the results of this Detailed Assessment.

The results will also inform the Manchester Airport Environment Plan to 2015, and will allow the City Council and airport authorities to effectively target measures to protect the environment.

Manchester City Council is committed to achieving the air quality objectives. The city council will continue to work in partnership with the citizens of Manchester, the other Greater Manchester Local Authorities, Manchester Airport Plc, and a wide range of other stakeholders, in the development and implementation of an effective Air Quality Action Plan.

111 6: Detailed Assessment of PM 10 Particulate Matter

The Update & Screening Assessment identified a number of locations where there was a risk of the 2004 air quality objectives for PM 10 being exceeded.

These areas included locations with relevant public exposure close to a number of busy road junctions, and city centre roads used by a high proportion of buses or HGVs.

Air quality monitoring carried out in Manchester indicates that exceedences of the 2004 air quality objectives will not occur.

Atmospheric dispersion modelling was carried out and the results indicated that the 2004 air quality objectives would be met at all locations in Manchester.

Concentrations of PM 10 in Manchester are expected to decrease over time. This reduction is due to the impact of the increasing use of emissions control technology on road vehicles.

More stringent PM 10 air quality objectives have been proposed for 2010. Existing monitoring data was projected to 2010, and atmospheric dispersion modelling was used to predict 2010 concentrations of PM 10 .

Despite the expected reduction in PM 10 concentrations, some roadside locations will experience exceedences of the 2010 annual average objective.

Results from the Detailed Assessment of PM 10 will be used to inform the Manchester Air Quality Action Plan.

112