2021 Air Quality Annual Status Report (ASR)
In fulfilment of Part IV of the Environment Act 1995 Local Air Quality Management
Date: July 2021
Wiltshire Council
Information Wiltshire Council Details
Local Authority Officer Gary Tomsett, Brett Warren, Peter Nobes
Department Public Protection
Address County Hall, Bythesea Road, Trowbridge. BA14 8JN
Telephone 01225 770556
E-mail [email protected]
Report Reference Number ASR_2021_Wiltshire Council
Date July 2021
LAQM Annual Status Report 2021 Wiltshire Council
Executive Summary: Air Quality in Our Area
Air Quality in Wiltshire
Air pollution is associated with several adverse health impacts. It is recognised as a contributing factor in the onset of heart disease and cancer. Additionally, air pollution particularly affects the most vulnerable in society: children, the elderly, and those with existing heart and lung conditions. There is also often a strong correlation with equalities issues because areas with poor air quality are also often less affluent areas1,2.
The mortality burden of air pollution within the UK is equivalent to 28,000 to 36,000 deaths at typical ages3, with a total estimated healthcare cost to the NHS and social care of £157 million in 20174.
The air quality in Wiltshire is predominantly very good with most of the county having clean unpolluted air. However, there are a small number of locations where the combination of traffic volume, road layout and topography has resulted in pollutants being trapped allowing concentrations to increase to unacceptable levels.
There are two pollutants included within the Local Air Quality Management regime that are the cause of concern in Wiltshire: nitrogen dioxide (NO2) and fine particulate matter
(PM10).
In recent times the trend has been toward improving air quality in the county of Wiltshire and while this is borne out by the 2020 diffusion tube results with a reduction of annual mean levels of Nitrogen Dioxide at all 72 of our monitoring sites, the impact of the COVID19 pandemic restrictions cannot be ignored. The real time monitoring shows a similar trend with average mean levels down at all sites for both NO2 and PM10.
Only 3 exceedances of the 24hour mean for PM10 were reported, all at one site.
1 Public Health England. Air Quality: A Briefing for Directors of Public Health, 2017
2 Defra. Air quality and social deprivation in the UK: an environmental inequalities analysis, 2006
3 Defra. Air quality appraisal: damage cost guidance, July 2020
4 Public Health England. Estimation of costs to the NHS and social care due to the health impacts of air pollution: summary report, May 2018
LAQM Annual Status Report 2021 i Wiltshire Council
There are currently eight Air Quality Management Areas (AQMAs) in Wiltshire which have been declared in respect of the annual mean objective for nitrogen dioxide, located in the following towns.
• Westbury
• Devizes
• Calne
• Marlborough
• Salisbury
• Bradford on Avon
There are three separate AQMAs declared for Salisbury: the city centre, the A30 London Road between St Mark’s roundabout and the railway allotments and Wilton Road between St Paul’s roundabout and Skew Bridge which is part of the A36 trunk road and falls within the control of the Highways England.
The AQMA in Bradford on Avon was also declared in respect of the annual mean objectives for PM10. This aspect of the order has now been revoked due to continued compliance with the relevant objective. Maps of the Wiltshire AQMAs are available via the Wiltshire Air Quality website (http://www.wiltshireairquality.org.uk).
The Council has established local air quality steering groups to spearhead local initiatives to improve air quality where AQMAs have been declared. These groups report directly to their Area Boards. The groups are composed of local councillors, interest groups and private individuals and they draw upon expertise of other services and experts as they deem necessary. They are tasked with reporting to their Area Board annually. Group activity varies across the county and we will revisit Marlborough and Westbury Area Boards to provide support and assistance.
There is a considerable amount of activity being undertaken by Wiltshire Council that can influence air quality. Table 2.2 summarises the key measures contained in our action plan. We have adopted a high-level broad approach to ensure the document is accessible with links to relevant supporting information and other council initiatives and strategies.
LAQM Annual Status Report 2021 ii Wiltshire Council
Actions to Improve Air Quality
Whilst air quality has improved significantly in recent decades and will continue to improve due to national policy decisions, there are some areas where local action is needed to improve air quality further.
The 2019 Clean Air Strategy5 sets out the case for action, with goals even more ambitious than EU requirements to reduce exposure to harmful pollutants. The Road to Zero6 sets out the approach to reduce exhaust emissions from road transport through a number of mechanisms; this is extremely important given that the majority of Air Quality Management Areas (AQMAs) are designated due to elevated concentrations heavily influenced by transport emissions.
Bradford on Avon one-way system
Bradford on Avon one-way system for social distancing was introduced in August 2020 via the use of an Experimental Traffic Regulation Order (ETRO) and continues to operate in to 2021. We have collected a substantial body of data on traffic volumes, speeds, fleet breakdown and air quality from several roads in the town, and we have compared these against the baseline, pre-pandemic figures. We will be drawing on this evidence base as part of our work in relation to our new AQAP which will assist in providing evidence to support the continuation of the scheme as a key air quality measure.
Revised Air Quality Strategic Planning Document
The Wiltshire Local Plan identifies a significant demand for new housing; however, developments can contribute to a worsening of air quality. Since our last Supplementary Planning Document (SPD) in 2012, there have been substantial changes in national and local air quality objectives, with the number of areas or poor air quality in Wiltshire increasing in number also. Consequently, an updated SPD is urgently required, one which provides clarity to developers regarding what we expect from them in terms of air quality
5 Defra. Clean Air Strategy, 2019
6 DfT. The Road to Zero: Next steps towards cleaner road transport and delivering our Industrial Strategy, July 2018
LAQM Annual Status Report 2021 iii Wiltshire Council which is proportionate to the type of development. Our new SPD requires developers to address the cumulative impact of the following, which in turn establishes the level of mitigation required for their development:
- Air quality assessment including the size of the development and location
- Associated traffic with the development
- Further considerations including topography, industrial developments, timescale of construction/demolition
- Source and receptor sites that have been granted planning permission but where no development has yet taken place
- Potential for cumulative impacts of other developments in the locality that also have the potential to adversely affect air quality
The aim is to secure mitigation either directly or if more appropriate, by offsetting via s106 and CIL funding applications. We will be linking offset mitigation with our new AQAP. The AQAP will contain a range of specific measures to combat area of poor air quality within each of our AQMAs. The measures are based on detailed dispersion modelling and so we have confidence as to their effectiveness.
Significant research into how to succinctly present this information to developers has been conducted. Incorporating our 2012 SPD, looking at new policies and guidance from authoritative bodies and inspiration from other council SPD’s has enabled us to create a document which gives developers a simplified, step by step process into what is required to negate further air quality decline from developments in Wiltshire. The new Air Quality Hub has also provided a valuable source of information when carrying out this review.
We have also linked the mitigation into the council’s emerging EV charging infrastructure strategy to ensure a more strategic targeting of resources so that the right charging points (i.e Fast 7kw AC, Rapid 50kw DC and Ultra Rapid 200kw DC) are installed in the correct locations.
AQAP Planning
At the time of writing the 2020 ASR, our intention was to have completed the AQAP by now. Unfortunately our plans were delayed due to a combination of an unprecedented volume of reactive compliant work, the loss of a member of staff who specialised in air quality work and additional finance controls. Although we have had to overcome
LAQM Annual Status Report 2021 iv Wiltshire Council challenges, we have been able to progress this project. We have now finalised the traffic emission model which now aligns well with our network of passive diffusion tubes. As such we can use this as a mechanism to reliably predict the impact of various measures on local air quality within our AQMAs. Source apportionment has been completed which has identified the NOx contribution from each vehicle type along with a breakdown of required reductions within each AQMA. We have worked closely with colleagues in our highways team who have provided us with up to date detailed traffic data within each of our AQMAs.
We are currently in consultation with our partners on a proposed ‘long list’ of measures for each AQMA. Our partners include colleagues working in the following teams:
• Spatial/Strategic Planning • Development Control • Public Health • Transport/Highways • Carbon Reduction • Corporate Economic Recovery • Highways England
We are reliant on the knowledge and expertise of our key partners to help us identify and evaluate proposed measures.
Following this consultation with our partners, a total of 13 measures will be quantitatively modelled for the AQAP.
Positive working relationships have been formed during this consultation exercise which has enabled knowledge sharing between departments. This has allow us to be aware of projects that have the potential to improve air quality that may be included in our AQAP, such as the Salisbury Future High Street Fund which aims to improve and facilitate connections to and from city’s train station by encouraging cycling and walking.
Conclusions and Priorities
The continuous air quality monitoring across Wiltshire has confirmed that no exceedances of the Particulate Matter air quality objectives (both for annual mean and 24-hour mean) in 2020. The annual mean levels were like those recorded in 2019. Exceedances of the 24- hour mean was recorded at just one of our 3 sites with the individual site total well below the Air Quality objective.
LAQM Annual Status Report 2021 v Wiltshire Council
In respect of the NO2 monitoring, the continuous monitoring has shown improvements in the annual mean levels at all 4 operational sites (Salisbury, Devizes, Bradford on Avon and Royal Wootton Bassett) when compared to 2019. No exceedances of the 1 hour mean objective was recorded across the county, down from 1 in 2019 and 5 in 2018.
These results are backed up by the passive monitoring which has shown a significant decrease in the number of exceedances reported with only 3 sites exceeding the annual mean objective at the façade of relevant exposure, down from 8 in 2019. A decrease in the annual mean level was noted at all our passive monitoring sites, clearly shown in the graphs presented in Appendix A.
None of the sites reporting an exceedance were outside of existing AQMA’s.
Local Engagement and How to get Involved
Wiltshire Council has a dedicated website for air quality administered by both Public Health Wiltshire and Public Protection Services. The site is designed as a resource for consultants, students, and residents with an interest in air quality. Individuals can sign up to the “Know and Respond” text alerts system to receive alerts of episodes of poor air quality, download their own reports and find a range of other information on air quality. The site can be found at http://www.wiltshireairquality.org.uk
In the areas where AQMAs have been declared working groups have been established. These groups include members of the public. Further information about these groups is available here: http://www.wiltshire.gov.uk/council-democracy-area-boards
LAQM Annual Status Report 2021 vi Wiltshire Council
Table of Contents
Executive Summary: Air Quality in Our Area ...... i Air Quality in Wiltshire ...... i Actions to Improve Air Quality ...... iii Conclusions and Priorities ...... v Local Engagement and How to get Involved ...... vi 1 Local Air Quality Management ...... 1 2 Actions to Improve Air Quality ...... 2 Air Quality Management Areas ...... 2 Progress and Impact of Measures to address Air Quality in Wiltshire Council ...... 5
PM2.5 – Local Authority Approach to Reducing Emissions and/or Concentrations ...... 14 3 Air Quality Monitoring Data and Comparison with Air Quality Objectives and National Compliance ...... 15 Summary of Monitoring Undertaken ...... 15 3.1.1 Automatic Monitoring Sites ...... 15 3.1.2 Non-Automatic Monitoring Sites ...... 15 Individual Pollutants ...... 16
3.1.3 Nitrogen Dioxide (NO2) ...... 16
3.1.4 Particulate Matter (PM10) ...... 17
3.1.5 Particulate Matter (PM2.5) ...... 17 Appendix A: Monitoring Results ...... 18 Appendix B: Full Monthly Diffusion Tube Results for 2020 ...... 47 Appendix C: Supporting Technical Information / Air Quality Monitoring Data QA/QC ...... 51 New or Changed Sources Identified Within Wiltshire Council During 2020 ...... 51 Additional Air Quality Works Undertaken by Wiltshire Council during 2020 ...... 51 QA/QC of Diffusion Tube Monitoring ...... 51 Diffusion Tube Annualisation ...... 52 Diffusion Tube Bias Adjustment Factors ...... 52
NO2 Fall-off with Distance from the Road ...... 53 QA/QC of Automatic Monitoring ...... 53 Manual calibration ...... 53
PM10 Monitoring Adjustment ...... 55 Automatic Monitoring Annualisation ...... 55
NO2 Fall-off with Distance from the Road ...... 55 Appendix D: Map(s) of Monitoring Locations and AQMAs ...... 58 Appendix E: Summary of Air Quality Objectives in England ...... 78 Appendix F: Impact of COVID-19 upon LAQM ...... 79 Impacts of COVID-19 on Air Quality within Wiltshire Council ...... 80
LAQM Annual Status Report 2021 vii Wiltshire Council
Opportunities Presented by COVID-19 upon LAQM within Wiltshire Council ...... 80 Challenges and Constraints Imposed by COVID-19 upon LAQM within Wiltshire Council ...... 81 Glossary of Terms ...... 84 References ...... 85
LAQM Annual Status Report 2021 viii Wiltshire Council
Figures
Figure A.1 – Trends in Annual Mean NO2 Concentrations ...... 33 3 Figure A.2 – Trends in Number of NO2 1-Hour Means > 200µg/m .... Error! Bookmark not defined.
Figure A.3 – Trends in Annual Mean PM10 Concentrations ...... 44 3 Figure A.4 – Trends in Number of 24-Hour Mean PM10 Results > 50µg/m ...... Error! Bookmark not defined.
Figure A.5 – Trends in Annual Mean PM2.5 Concentrations . Error! Bookmark not defined. Figure D.1 – Map of Non-Automatic Monitoring Site ...... 58
Tables
Table 2.1 – Declared Air Quality Management Areas ...... 3 Table 2.2 – Progress on Measures to Improve Air Quality...... 8 Table A.1 – Details of Automatic Monitoring Sites ...... 18 Table A.2 – Details of Non-Automatic Monitoring Sites ...... 19 3 Table A.3 – Annual Mean NO2 Monitoring Results: Automatic Monitoring (µg/m ) ...... 25 3 Table A.4 – Annual Mean NO2 Monitoring Results: Non-Automatic Monitoring (µg/m ) .... 26 3 Table A.5 – 1-Hour Mean NO2 Monitoring Results, Number of 1-Hour Means > 200µg/m ...... 42 3 Table A.6 – Annual Mean PM10 Monitoring Results (µg/m ) ...... 43
Table A.7 – 24-Hour Mean PM10 Monitoring Results, Number of PM10 24-Hour Means > 50µg/m3 ...... 45 3 Table A.8 – Annual Mean PM2.5 Monitoring Results (µg/m ) ...... 46
Table A.9 – SO2 2020 Monitoring Results, Number of Relevant Instances ...... Error! Bookmark not defined. 3 Table B.1 – NO2 2020 Diffusion Tube Results (µg/m ) ...... 47 Table C.1 – Bias Adjustment Factor ...... 52 Table C.2 – Annualisation Summary (concentrations presented in µg/m3) Error! Bookmark not defined. Table C.3 – Local Bias Adjustment Calculation ...... 56 3 Table C.4 – NO2 Fall off With Distance Calculations (concentrations presented in µg/m ) 57 Table E.1 – Air Quality Objectives in England ...... 78 Table F 1 - Impact Matrix ...... 83
LAQM Annual Status Report 2021 ix Wiltshire Council
1 Local Air Quality Management
This report provides an overview of air quality in Wiltshire Council during 2020. It fulfils the requirements of Local Air Quality Management (LAQM) as set out in Part IV of the Environment Act (1995) and the relevant Policy and Technical Guidance documents.
The LAQM process places an obligation on all local authorities to regularly review and assess air quality in their areas, and to determine whether the air quality objectives are likely to be achieved. Where an exceedance is considered likely the local authority must declare an Air Quality Management Area (AQMA) and prepare an Air Quality Action Plan (AQAP) setting out the measures it intends to put in place in pursuit of the objectives. This Annual Status Report (ASR) is an annual requirement showing the strategies employed by Wiltshire Council to improve air quality and any progress that has been made.
The statutory air quality objectives applicable to LAQM in England are presented in Table E.1.
LAQM Annual Status Report 2021 1 Wiltshire Council
2 Actions to Improve Air Quality
Air Quality Management Areas
Air Quality Management Areas (AQMAs) are declared when there is an exceedance or likely exceedance of an air quality objective. After declaration, the authority should prepare an Air Quality Action Plan (AQAP) within 12 months setting out measures it intends to put in place in pursuit of compliance with the objectives.
A summary of AQMAs declared by Wiltshire Council can be found in Table 2.1. Further information related to declared or revoked AQMAs, including maps of AQMA boundaries are available online at http://www.wiltshireairquality.org.uk
The table presents a description of the 8 AQMAs that are currently designated within Wiltshire. Appendix D: Map(s) of Monitoring Locations and AQMAs provides maps of AQMAs and also the air quality monitoring locations in relation to the AQMAs. The air quality objective pertinent to the current AQMA designations is solely the Nitrogen dioxide annual mean.
LAQM Annual Status Report 2021 2 Wiltshire Council
Table 2.1 – Declared Air Quality Management Areas AQMA Date of Pollutants One Line Is air quality Level of Level of Name and Web Link to AQAP Name Declaration and Air Description in the AQMA Exceedance: Exceedance: Date of Quality influenced Declaration Current Year AQAP Objectives by roads Publication controlled by Highways England? AQMA 1 23/11/2007 NO2 Annual An area YES N/A 33 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Salisbury Mean encompassing the Action Plan City Centre city centre for Wiltshire bounded by main June 2015 ring roads to North, East and the River Avon to the East and South. AQMA 2 11/11/2007 NO2 Annual Residential YES 43 µg/m3 30 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Salisbury Mean properties in Action Plan London vicinity of St for Wiltshire Road Mark’s June 2015 roundabout and following London Road as far as the railway tunnel. AQMA 3 03/03/2016 NO2 Annual Part of Devizes YES 58 µg/m3 46 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Salisbury Mean Road and Wilton Action Plan Wilton Road Road as far as for Wiltshire (extended) Skew Bridge June 2015 AQMA 4 26/11/2001 NO2 Annual Main roads in the NO 65 µg/m3 51 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Bradford on Mean centre of the Action Plan Avon town. for Wiltshire June 2015 AQMA 5 - 26/11/2001 NO2 Annual Main A350 NO 52 µg/m3 30 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Westbury Mean through centre of Action Plan the town. for Wiltshire June 2015 AQMA 6 12/05/2011 NO2 Annual The whole town NO 59 µg/m3 38 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Marlborough Mean as described by Action Plan town council for Wiltshire boundary. June 2015 AQMA 7 23/11/2009 NO2 Annual Main roads NO 51 µg/m3 32 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Devizes Mean through the town. Action Plan
LAQM Annual Status Report 2021 3 Wiltshire Council
AQMA Date of Pollutants One Line Is air quality Level of Level of Name and Web Link to AQAP Name Declaration and Air Description in the AQMA Exceedance: Exceedance: Date of Quality influenced Declaration Current Year AQAP Objectives by roads Publication controlled by Highways England? for Wiltshire June 2015 AQMA 8 21/02/2013 NO2 Annual Main roads NO 60 µg/m3 41 µg/m3 Air Quality http://www.wiltshireairquality.org.uk/reports Calne Mean through the town Action Plan for Wiltshire June 2015 ☒ Wiltshire Council confirm the information on UK-Air regarding their AQMA(s) is up to date ☒ Wiltshire Council confirm that all current AQAPs have been submitted to Defra
LAQM Annual Status Report 2021 4 Wiltshire Council
Progress and Impact of Measures to address Air Quality in Wiltshire Council
Defra’s appraisal of last year’s ASR concluded the following points and our comment follows each in italic font:
1. The Council have included a link to a map of their AQMAs and monitoring locations. It is understood that the Council are currently renewing their mapping system. A suggestion to this would be to have a map with both the AQMAs and monitoring locations so that it can be easily identified which monitoring locations are within which AQMA. This has been actioned although the mapping issues are still relevant.
2. It is encouraging to see that the Council have included 22 new monitoring locations. In doing this the Council have demonstrated that they are taking an active approach to reviewing and amending their monitoring program. The Council are encouraged to continue to review their monitoring network on a regular basis and add and relocate tubes where they deem appropriate. Noted, while the 2020 monitoring sites were largely unchanged (one site moved), a review for 2021 was undertaken and several sites have changed and will be reported on in the 2022 ASR.
3. The national bias adjustment factor has been used however it would be beneficial for the Council to also include their locally derived bias adjustment factor. This way a comparison of the two factors and a justification of the factor chosen can be provided. The locally derived factor has been used in this ASR.
4. The Council has established a local air quality steering group to spearhead local initiatives to improve air quality where AQMAs have been declared. This is encouraging to see and demonstrates the Councils active engagement with local stakeholders with regards to air quality. This project continues.
5. The Council have incorrectly made reference to WASP scheme when discussing QA/QC procedures of diffusion tubes. This scheme has been superseded by AIR-PT. Can the Council please ensure that this is updated? Noted and actioned.
6. Alongside the graphs it would also be beneficial for the Council to include a written
discussion of NO2 trends within the AQMAs. In addition to this a discussion on the ‘status’ of AQMAs would be greatly welcomed, i.e. whether an AQMA can be considered for revocation/amendment. Noted and actioned.
7. There appears to be an error in Table 2.1 for AQMA 4. The NO2 concentration written is 53 for the AQMA4, whilst in other tables the concentration for this AQMA is 55. Can
LAQM Annual Status Report 2021 5 Wiltshire Council
the Council please ensure that this is rectified, and more care is taken in future ASRs. Noted.
8. It would be useful if Section 2.3 could make reference to the Public Health Outcomes
Framework, and the local indicator for PM2.5 in the district. The Council may wish to consider comparing the ‘D01 - Fraction of mortality attributable to particulate air pollution indicator’ value for Wiltshire to nearby LAs and National indicator values. This can be found in the link below. https://fingertips.phe.org.uk/profile/public-health-outcomes- framework/data/page-options/ovw-do- 0#page/0/gid/1000043/pat/6/par/E12000004/ati/302/are/E06000015/iid/90362/age/1/sex/1/ cid/4/tbm/1/page-options/cin-ci-4_car-do-0_ovw-do-0 This has not been added, the link provided does not function but will be considered in future reporting.
Wiltshire Council has taken forward several direct measures during the current reporting year of 2020 in pursuit of improving local air quality. Details of all measures completed, in progress or planned are set out in Table 2.2. Where there have been, or continue to be, barriers restricting the implementation of the measure, these are also presented within Table 2.2.
Wiltshire Council expects the following measures to be completed over the course of the next reporting year:
Wiltshire Council will be updating its action plan over the coming months and as such there will be a new set of measures that are based on high resolution modelling to be included. The measures will be more specific and measurable than the previous action plan. The previous ASR had 22 measured listed (titled PP) which were not part of the previous action plan. They were included in order to demonstrate that we actively work on air quality related schemes either via the planning process or by improving our monitoring network. However, we have decided that it is not practical to continue to include all of these actions due to the risk of table 2.2 becoming focused away from the action plan. An example of this is our inclusion of funding towards EV charge points in the district as part of section 106 agreements. As a council we are now actively asking for S106 or CIL funding via the planning process to improve the EV charging network in Wiltshire. As such, continuing to include this information in table 2.2 is simply not sustainable and we have removed those actions of this type of similar from last year’s report that fall into this category.
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Whilst the measures stated above and in Table 2.2 will help to contribute towards compliance, Wiltshire Council anticipates that further additional measures not yet prescribed will be required in subsequent years to achieve compliance and enable the revocation of the AQMA’s within Wiltshire.
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Table 2.2 – Progress on Measures to Improve Air Quality DEFRA Reduction Estimated / Key Year AQ Estimated in Pollutant / Measure Actual Organisations Funding Funding Performan Measure Category Classification Measure Grant Cost of Measure Status Emission Progress to Date No. Completion involved Source Status ce Introduced Funding Measure from Year Indicator Measure BATHNES CAZ discussions may result in CAZ related monitoring in WC area. Policy No Set up links Guidance Not Group We are in contact with with other LAs BGSW group WAQS1 and Other policy Ongoing Ongoing n/a funded <£10k Implementation n/a meetings/ two authorities named in within the of Authorities Development contact the Governments southwest. Control consultation regarding experience of declaration of a CAZ following requests from a Community AQ group Ongoing uptake of Home Home Run Run App metrics Investigate the show up to Barriers- Willingness of feasibility of No 14% of schools to actively Alternatives Not innovative Wiltshire Highway school run promote; they see it as WAQS5 to private Other Ongoing Ongoing funded <£10k Aborted 0.2 µg/m3 solutions for Council Services cars kept "another thing on their vehicle use school travel off the road list" plans at some Positives - useful data, schools in and another tool we can scheme. offer schools to reduce cars on the school run. Local Variable ongoing activity Establish democracy across 6 groups community Promoting Not Establishm Wiltshire with mix of No CI01 AQAP groups Travel Other Ongoing Ongoing funded <£10k Implementation n/a ent of Council CIL, s.106 Several groups are active under the Area Alternatives groups and precept some will need to Board etc.. revisited Area Boards to report to Public Protection Service Ongoing annually on Not Delivery of Public via the Wiltshire Area Board CI02 progress made Ongoing Ongoing No funded <£10k Implementation n/a annual Information Internet Council Budgets Westbury likely to re- with report establish AQ Group community action plans and priority actions Provide AQ data and information to Ongoing Area Boards to Not provision of Public via the Wiltshire CI03 assist with the Ongoing Ongoing n/a No funded <£10k Implementation n/a data Information Internet Council Public Access to Wiltshire production of annually Air Quality Data community actions & plans. Support On hold Post AQAP Not Wiltshire Public via other Wiltshire Annual CIO4 Ongoing refresh Area Boards funded <£10k Implementation n/a Forum Information mechanisms Council meeting Review of AQAP will 2021 Community trigger revitalisation.
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Area No Partnerships in enabling the dissemination of good practice AQ projects
Support the Ongoing implementation of LTP3 & AQ modelling work with Development Transportation Planners Transport Transport Not See of LTP4. Wiltshire No to fit modelling to AQAP T01 Planning and Other Ongoing 2022 Planners/ funded <£10k Implementation n/a Wiltshire Supporting Council objectives. New AQAP Infrastructure s.106 LTP3 strategies to due 2021/22 is likely to secure include longer term improvements relevant measures based in AQ on modelling predictions Ongoing Integrate AQ into wider Engagement with Spatial polices and Planning re. updating strategies Policy CP55 to better reflect AQ Air Quality within the Guidance Not Strategy. This is a key Planning and Wiltshire DSP01 council and the and 2015 2021 n/a funded <£10k Implementation n/a adoption area of work for us and Policy Council adoption of Development No links to the work we are Guidance Core policy 55 Control doing to revise our SPD on AQ in the to ensure consistency and Wiltshire Core clarity for developers to Strategy ensure measures are proportionate to AQ risks. Adoption of the Policy Draft Air Quality Ongoing Guidance Not Supplementary Planning and Wiltshire No DSP02 and 2016 2021 n/a funded <£10k Planning n/a adoption Planning Policy Council Updating SPD in tandem Development Guidance on Guidance with AQAP review. Control Air Quality Integrate Green infrastructure considerations Subject to core policy into Council update Policy / Policy Air Quality Strategy and Guidance Wiltshire n/a No Not Planning and Green infrastructure DSP03 adopt the and 2018 2021 Council funded <£10k Implementation n/a adoption Policy strategy will be developed Green Development Guidance following competition and Infrastructure Control adoption of the draft open strategy to space strategy as SPD. support core policy 52 of the Wiltshire Core Strategy Provision of funding for AQAP and Ongoing related matters Transport Wiltshire s.106/CIL Not tbc from Funding DSP05 through s.106 Planning and Other Ongoing Ongoing Council No funded <£10k Implementation projects achieved Regulation 123 List Oct agreements Infrastructure 2016. Wiltshire CIL. with developers and the CIL
LAQM Annual Status Report 2021 9 Wiltshire Council
PH Wiltshire Ongoing Standalone AQ
website with Not Wiltshire Air Quality access to real- Public via the Wiltshire PH funded No Provision of PH01 2015 Ongoing funded <£10k Implementation n/a website incorporating real time AQ data & Information Internet Council service time data and <£10k Know and Know and Respond Respond service service Public Protection will contribute to Policy the JSNA and Guidance Wiltshire n/a No Not Ongoing Inclusion of PH02 State of and Other policy 2015 Ongoing Council funded <£10k Implementation n/a Air Quality Environment Development None Reports on AQ Control within the County Identify through partnership Salisbury AQ Highways/ working with group and Highways Reduction Highways Highways England No Consultation Not of annual England Traffic England S01 Other 2018 Ongoing funded <£10k Implementation tbc mean to specific Management supported by Currently integral to below measures to Wiltshire AQAP review objective reduce NO2 on Council Wilton Road (A36 Trunk road) Salisbury Implementation of Salisbury Transport Strategy (STS) Wiltshire Wiltshire Not Ongoing Traffic See S02 measures that Other 2019 Ongoing Council Council No funded <£10k Implementation tbc Management strategy offer None opportunity to improve local air quality. Salisbury AQAP Ongoing Transport Not developed, Wiltshire Wiltshire Adoption of S03 Planning and Other 2018 Ongoing funded <£10k Implementation n/a group working Council Council No plan Area Board annual report Infrastructure on funding for 2016 measures Marlborough AQ working Ongoing Transport Not group to Wiltshire Wiltshire Adoption of M01 Planning and Other 2018 2021 funded <£10k Implementation n/a produce a Council Council No plan Area Board Activity Infrastructure community Stalled due to COVID 19 AQAP Devizes AQ Ongoing working group Transport Not Adoption of D01 to produce a Planning and Other 2019 2021 Wiltshire Wiltshire No funded <£10k n/a plan Area Board Activity community Infrastructure Council Council Stalled due to COVID 19 AQAP Implementation Strategic GTMA of the Devizes highway
Transport improvements, Not Annual Traffic The continued D02 Strategy Re-prioritising 2016 Ongoing funded <£10k Implementation Unknown Average Management implementation of the measures that road space No NO2 Devizes Transport provide the away from Strategy will address key opportunity to cars, inc
LAQM Annual Status Report 2021 10 Wiltshire Council
improve air Access Wiltshire Wiltshire pollution hotspots in the quality within management, Council Council town. the town Selective vehicle priority, bus priority, high vehicle occupancy lane Implement key junction improvements identified by the Devizes Transport strategy. The junction of A361 / London Road is being Effects being monitored brought
forward and Wiltshire Wiltshire No Annual Community action plan, delivery of the Traffic Council Council Funded £500k - D03 Other 2017 2019 Implementation Unknown Average Devizes transport Shanes Castle Management £1m NO2 Strategy - Windsor Drive junction junction improvements improvement now complete has started. New cycle facilities built including towpath improvements through the town and a contra flow cycle lane. Calne AQ TBC working group Transport Not Annual
C01 to produce a Planning and Other 2018 2021 Wiltshire Wiltshire No funded <£10k Implementation n/a Average AQ Group Activity Stalled Community Infrastructure Council Council NO2 due to COVID 19 AQAP Developme BATHNES CAZ works Working with Transport BATHNES & DEFRA nt of CAZ + commenced BATHNES on 2021 (later Funded £10k - ST01 Planning and Other 2019 Wiltshire No Implementation TBC Monitoring development of half) £50k Infrastructure Council and Agreeing inter authority CAZ evaluation evaluation/monitoring Strategic highway improvements, Re-prioritising Highways road space England away from Designated cars, including Highways Highways No Not Traffic Initiation of Ongoing HE1 Fund Project access 2019 Ongoing England England funded <£10k Implementation unknown Management Projects ideas - management, Salisbury x6 Selective (see also S01) vehicle priority, high vehicle occupancy lane
LAQM Annual Status Report 2021 11 Wiltshire Council
Ongoing Salisbury AQ Policy Air Quality Spatial Group - Guidance Not Planning and Planning & AQ TBC No Policy Completion of Core S04 Develop Green and 2019 Ongoing funded <£10k Implementation n/a Policy Group change Strategy review Infrastructure Development Guidance determines when Green Strategy Control Inf can be progressed Know & Ongoing use Respond Text Wiltshire Wiltshire Not Alert details Public Council Council Awareness PH03 Via leaflets 2016 Ongoing funded <£10k Implementation Unknown Doctors surgeries now included in Information No levels have TV graphics NHS leaflet regarding K&R from CCG Company Buses in active use. Vehicle Promoting Procurement - Red Bus & Red Bus Partially Electric Bus Low Completed/ £500k - Objective x4 electric buses PP10 Prioritising 2019 Wiltshire Wiltshire No funded Completed Unknown Roll Out Emission Ongoing £1m compliance introduced and further uptake of low Council Transport developments emission encouraged. vehicles AQAP measures will be both viable Project plan and meetings evidence commenced. Source based and apportionment completed. link into Review of possible other transport measures now Wiltshire objectives on-going. Review of good Council, n/a inc s.106, practice; eg York, Highways No Funded £10k - CIL and a PP13 AQAP Refresh Other Other 2020 2021 Planning Unknown Lancaster. England £50k strategic
planning Resources to commit to document project in addition to core on AQ. work. Reliance on key Reduction partners for elements of of NO2 project who may have levels in different priorities. AQMA to below that of national objectives. LTP4 will seek Initial discussions to reduce the Wiltshire tbc Not need to travel Traffic Council No Requires societal modal PP15 Other 2019 tbc funded <£10k Implementation Unknown - by encouraging Management shift towards alternative
use of active travel especially for local travel modes journeys. Strategic highway Bradford on Improvement improvements, Avon Town Wiltshire in AQ Re-prioritising Council / Council via expected road space Councillors/ Experimental although Implemented August away from Wiltshire measure 2020 cars, including Council introduced in Bradford On Traffic access No Funded £10k - August 2020 Improveme PP21 Avon One Way 2019 N/A Completed Substantial amount of Management management, £50k so too early nt in AQ System traffic data obtained and selective to say. The we will use this to support vehicle Covid continuation of scheme. priority, bus pandemic priority, high has arguably vehicle had a bigger occupancy impact lane
LAQM Annual Status Report 2021 12 Wiltshire Council
Works in progress. Tow Path – 4 out 5 phases Devizes AQ Provision of complete. No funding for Devizes Canal Alternatives Partially Group & CRT No £500k - cycle way phase 5 identified at this PP22 Towpath Cycle to private Other 2019 tbc funded Implementation Unknown Wiltshire £1m along canal stage. route vehicle use Council towpath Works ongoing
LAQM Annual Status Report 2021 13 Wiltshire Council
PM2.5 – Local Authority Approach to Reducing Emissions and/or Concentrations
As detailed in Policy Guidance LAQM.PG16 (Chapter 7), local authorities are expected to work towards reducing emissions and/or concentrations of PM2.5 (particulate matter with an aerodynamic diameter of 2.5µm or less). There is clear evidence that PM2.5 has a significant impact on human health, including premature mortality, allergic reactions, and cardiovascular diseases.
Wiltshire Council is taking the following measures to address PM2.5:
Only one of the 8 Wiltshire AQMAs was declared with reference to an exceedance of the annual mean objective for PM10 and the process to revoke this aspect of the Bradford on Avon AQMA Order was commenced in late 2020 and completed in early 2021. Recent 3 results had shown PM10 levels had fallen below 25ug/m .
Wiltshire Council has Turnkey Osiris units which are available to be deployed to Major Incidents declared by the Emergency Services (e.g. major fires) and for periodic deployment to locations around the county. One has been deployed to Marlborough and the results can be accessed via the link in the next section. This unit uses a non-reference 3 monitoring technique. However, the data suggests levels of PM2.5 are below 10ug/m .
The Council is currently working to reduce levels of PM2.5 through its action plan which embraces many of the measures detailed in Annex A of Technical Guidance LAQM.TG16. The local community working groups will be looking at the measures outlined in Annex A as part of the development of their action plans.
LAQM Annual Status Report 2021 14 Wiltshire Council
3 Air Quality Monitoring Data and Comparison with Air Quality Objectives and National Compliance
This section sets out the monitoring undertaken within 2020 by Wiltshire Council and how it compares with the relevant air quality objectives. In addition, monitoring results are presented for a five-year period between 2016 and 2020 to allow monitoring trends to be identified and discussed.
Summary of Monitoring Undertaken
3.1.1 Automatic Monitoring Sites
Wiltshire Council undertook automatic (continuous) monitoring at 4 sites during 2020. Table A.1 in Appendix A shows the details of the automatic monitoring sites. In addition, Wiltshire Council monitored for fine particulates using a non-reference, indicative method in Marlborough during 2020. Results from this monitoring are also available on the Wiltshire Council Air Quality website (http://www.wiltshireairquality.org.uk/).
The http://www.wiltshireairquality.org.uk/ page presents automatic monitoring results for Wiltshire Council.
Maps showing the location of the monitoring sites are provided in Appendix D. Further details on how the monitors are calibrated and how the data has been adjusted are included in Appendix C.
3.1.2 Non-Automatic Monitoring Sites
Wiltshire Council undertook non- automatic (i.e. passive) monitoring of NO2 at 72 sites during 2020. Table A.2 in Appendix A presents the details of the non-automatic sites.
Maps showing the location of the monitoring sites are provided on the Wiltshire Council Air Quality website using the following link: http://www.wiltshireairquality.org.uk/data/non-auto-data?type=active
Maps of Diffusion Tube Monitoring Locations are also presented in Appendix D to this report.
LAQM Annual Status Report 2021 15 Wiltshire Council
Further details on Quality Assurance/Quality Control (QA/QC) for the diffusion tubes, including bias adjustments and any other adjustments applied (e.g. annualisation and/or distance correction), are included in Appendix C.
Individual Pollutants
The air quality monitoring results presented in this section are, where relevant, adjusted for bias, annualisation (where the annual mean data capture is below 75% and greater than 33%), and distance correction. Further details on adjustments are provided in Appendix C.
3.1.3 Nitrogen Dioxide (NO2)
Table A.3 and Table A.4 in Appendix A compare the ratified and adjusted monitored NO2 annual mean concentrations for the past five years with the air quality objective of 40µg/m3. Note that the concentration data presented represents the concentration at the location of the monitoring site, following the application of bias adjustment and annualisation, as required (i.e. the values are exclusive of any consideration to fall-off with distance adjustment).
For diffusion tubes, the full 2020 dataset of monthly mean values is provided in Appendix B. Note that the concentration data presented in Table B.1 includes distance corrected values, only where relevant. A local bias correction factor has been used to report diffusion tube monitoring results.
Table A.5 in Appendix A compares the ratified continuous monitored NO2 hourly mean concentrations for the past five years with the air quality objective of 200µg/m3, not to be exceeded more than 18 times per year.
No exceedances of any of the air quality objectives for NO2, both for annual mean and the 1-hour objective were reported in 2020 at any of the 4 Real Time analysers in Wiltshire.
The real time analyser for NO2 located at Royal Wootton Bassett was shut down at the end of 2020. Our intention is to relocate this following a full service although a suitable location has yet to be confirmed
The diffusion tube monitoring has reported only 3 sites with an exceedance of the annual mean ovjective for NO2. All 3 sites are within existing AQMAs and none were above 60 µg/m3, the level above which an exceedance of the 1-hour mean objective is also likely.
LAQM Annual Status Report 2021 16 Wiltshire Council
3.1.4 Particulate Matter (PM10)
Table A.6 in Appendix A: compares the ratified and adjusted monitored PM10 annual mean concentrations for the past five years with the air quality objective of 40µg/m3.
No exceedance of the annual mean objective for PM10 was reported in 2020 at any of the 3 Real Time analysers in Wiltshire.
Table A.7 in Appendix A compares the ratified continuous monitored PM10 daily mean concentrations for the past five years with the air quality objective of 50µg/m3, not to be exceeded more than 35 times per year.
The real time analyser located in Devizes (AM3) reported 3 exceedances of the 24-hour mean objective for PM10; the other units reported none.
Revocation of the AQMA for Annual Mean PM10 in Bradford on Avon is to be completed in 2021. No other changes to our other AQMA’s are proposed at this time.
3.1.5 Particulate Matter (PM2.5)
Wiltshire Council does not monitor specifically for PM2.5. However, it is possible to estimate levels from our ratified real time PM10 monitoring using guidance set out in TG16 where Chapter 7.111 states:
‘Where no appropriate local sites measuring both PM10 and PM2.5 are available, then a nationally derived correction ratio of 0.7 can be used’
Table A.8 in Appendix A presents the ratified and adjusted monitored PM2.5 annual mean concentrations for the past five years based upon the application of this correction factor to our annual mean results.
The results show that estimated annual mean levels of PM2.5 are low, with no site reporting an estimated annual mean greater than 15ug/m3 in 2020. No air quality objective is available for comparison.
LAQM Annual Status Report 2021 17 Wiltshire Council
Appendix A: Monitoring Results
Table A.1 – Details of Automatic Monitoring Sites Site Site Name Site Type X OS Y OS Grid Pollutants In AQMA? Monitoring Distance to Distance to Inlet ID Grid Ref Ref Monitored Which AQMA? Technique Relevant kerb of Height (Easting) (Northing) Exposure nearest (m) (m) (1) road (m) (2) AM1 Exeter St Salisbury Roadside 414547 129575 NO2, Yes AQMA 1 Chemiluminescent, 8 2.5 2 PM10 TEOM AM2 Masons Lane, Roadside 382533 161115 NO2, Yes AQMA 4 Chemiluminescent, 15 1.6 2 Bradford On Avon PM10 Beta attenuation AM3 Sidmouth St Devizes Roadside 400765 161458 NO2, Yes AQMA 7 Chemiluminescent, 4 2.5 2 PM10 TEOM AM4 High Street, Royal Roadside 406888 182711 NO2 No Chemiluminescent 10 1.8 3 Wootton Bassett
Notes: (1) 0m if the monitoring site is at a location of exposure (e.g. installed on the façade of a residential property). (2) N/A if not applicable
LAQM Annual Status Report 2021 18 Wiltshire Council
Table A.2 – Details of Non-Automatic Monitoring Sites Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT1 West View Urban 400000 161109 NO2 No 5 3 NO 2.5 Crescent, Background Devizes DT2 The Nursery, Roadside 399924 161729 NO2 Yes (Devizes) 1.5 2 NO 2.75 Devizes DT3 Shanes Castle, Kerbside 399763 161717 NO2 Yes (Devizes) 0 1.1 NO 2 Devizes DT4 Northgate St, Roadside 400210 161623 NO2 Yes (Devizes) 0 1.7 NO 2.5 Devizes DT5 Windsor Dr, Roadside 401788 162402 NO2 No 10 1.5 NO 2.5 Devizes DT6 Southgate, Roadside 400635 160982 NO2 Yes (Devizes) 0 1.8 NO 2.75 Devizes DT7 St James Roadside 400807 161389 NO2 Yes (Devizes) 0 2.3 NO 2.6 Place, Devizes DT8 Pewsey Library Urban 416230 160122 NO2 No 16 50 NO 2 Background DT9 Ashton Rd Roadside 418723 169048 NO2 No 0 5 NO 2.5 Trowbridge DT10 Herd St, Roadside 418942 169384 NO2 Yes 0 1.8 NO 2 Marlborough (Marlborough) DT11 Baylie Acre, Suburban 418944 169702 NO2 Yes 12 20 NO 2.5 Marlborough (Marlborough) DT12 Barn St, Roadside 418053 169224 NO2 Yes 1 1.6 NO 2.2 Marlborough (Marlborough) DT13 Salisbury Rd, Roadside 419296 168760 NO2 Yes 2.5 1.8 NO 2.4 Marlborough (Marlborough)
LAQM Annual Status Report 2021 19 Wiltshire Council
Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT14 Town Mill, Urban 419011 169012 NO2 Yes 0 1.5 NO 2.5 Marlborough Background (Marlborough) DT15 London Rd, Roadside 419152 169083 NO2 Yes 2.5 1.5 NO 2.25 Marlborough (Marlborough) DT16 Jones Lane, Roadside 423535 149822 NO2 No 2 2 NO 2.5 Tidworth DT17 Short Street, Roadside 426941 150795 NO2 No 5 2 NO 2.75 Ludgershall DT18 Horsebrook, Urban 400126 170745 NO2 No 10 2 NO 2.5 Calne Background DT19 New Road, Roadside 399873 170737 NO2 Yes (Calne) 0 2 NO 2.5 Calne (King George) DT20 London Road, Roadside 399988 170587 NO2 Yes (Calne) 1.5 2.1 NO 2.5 Calne DT21 Curzon St, Roadside 399657 171164 NO2 Yes (Calne) 0.5 1.8 NO 2.5 Calne DT22 Chippenham, Roadside 391647 174766 NO2 No 15 2 NO 2.2 Oaklands DT23 Chippenham, Roadside 390446 172480 NO2 No 7 2 NO 2.2 Westcroft DT24 Bourne House, Roadside 391712 173286 NO2 No 0 8.9 NO 2.25 Bath Rd, Chippenham DT25 Chippenham Roadside 390454 174047 NO2 No 13 2 NO 2.2 Allington Way DT26 Rowde Mead Urban 392468 172054 NO2 No 4 1.5 NO 2.2 Chippenham Background DT27 Station Hill, Roadside 391925 173579 NO2 No 17.5 2 NO 2.2 Chippenham
LAQM Annual Status Report 2021 20 Wiltshire Council
Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT28 Haynes Rd, Roadside 387240 151163 NO2 Yes 0 1.3 NO 2.1 Westbury (Westbury) DT29 Warminster Rd, Roadside 387166 150899 NO2 Yes 0 1.7 NO 2.5 Westbury (Westbury) DT30 West End, Roadside 387269 151507 NO2 No 1 1.5 NO 2.5 Westbury DT31 Oldfield Rd, Roadside 386491 151580 NO2 No 0 5 NO 2 Westbury DT32 Leighton Pk, Suburban 386739 150091 NO2 No 8 2 NO 2.5 Westbury DT33 Masons Lane, Roadside 382716 161228 NO2 Yes (BOA) 1 1.35 NO 2.5 Bradford On Avon DT34 Co-location Roadside 382538 161122 NO2 Yes (BOA) 15 1.6 YES 1.8 Masons lane BOA DT35 Co-location Roadside 382538 161122 NO2 Yes (BOA) 15 1.6 YES 1.8 Masons Lane BOA DT36 Co-location Roadside 382538 161122 NO2 Yes (BOA) 15 1.6 YES 1.8 Masons Lane BOA DT37 Market St, Kerbside 382544 161085 NO2 Yes (BOA) 0 0.95 NO 2.4 Bradford On Avon DT38 Meadowfield Urban 381878 160836 NO2 No 8 2 NO 2.5 Bradford (bg) Background DT39 Malmesbury, Roadside 393354 188636 NO2 No 5.3 2.45 NO 2.2 Snell Ave
LAQM Annual Status Report 2021 21 Wiltshire Council
Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT40 Malmesbury, Roadside 392312 187507 NO2 No 2.6 0.1 NO 2.2 Corn Gaston DT41 Royal Wootton Roadside 406944 182792 NO2 No 0.45 2 NO 2.5 Bassett N DT42 Melksham N Roadside 390118 164878 NO2 No 0 4 NO 2 DT43 Melksham Roadside 390136 164277 NO2 No 5 1.5 NO 2.5 Weavers Croft DT44 Melksham Roadside 390471 163657 NO2 No 10 2 NO 2.6 Market Place DT45 Rosset Gdns, Urban 384343 157806 NO2 No 5 1.5 NO 2.25 Trowbridge Background DT46 Newtown, Kerbside 385244 157541 NO2 No 0 2 NO 2.6 Trowbridge DT47 Woodcock Rd, Roadside 388678 144847 NO2 No 25 2 NO 2.75 Warminster DT48a Beanacre Roadside 390387 166196 NO2 No 6 2 NO 2.5 DT49 Wynsome, Roadside 383812 155257 NO2 No 0 4 NO 1.8 Southwick DT50 Box High Street Roadside 382595 168543 NO2 No 5 2.1 NO 2.2 DT51 Charles St, Urban 386577 170652 NO2 No 3 4 NO 2 Corsham Background DT52 74 London Roadside 415105 130641 NO2 Yes 0 8.4 NO 2.2 Road, (Salisbury) Salisbury DT53 2 Minster Kerbside 414373 129979 NO2 Yes 0 1.5 NO 3 Street, (Salisbury) Salisbury DT54 16 Greyfriars Roadside 414682 129425 NO2 Yes 0 13 NO 2.35 Close, (Salisbury) Salisbury
LAQM Annual Status Report 2021 22 Wiltshire Council
Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT55 Endless St Roadside 414500 130105 NO2 Yes 0 2.9 NO 2.6 (Salisbury) DT56 16 Winchester Roadside 414602 130054 NO2 Yes 1 1.5 NO 2.75 Street, (Salisbury) Salisbury DT57 11 Canadian Roadside 412872 130679 NO2 Yes 0 7.35 NO 2.3 Ave, Salisbury (Salisbury) DT58 35 The Roadside 410231 131553 NO2 No 0 13 NO 2.35 Avenue, Wilton DT59 123 South Roadside 413828 130142 NO2 Yes 0 1.5 NO 2.5 Western Road, (Salisbury) Salisbury DT60 Kickdom Close, Roadside 416641 140766 NO2 No 0 1.2 NO 2.4 Amesbury DT61 88 Park Street, Urban 414760 130567 NO2 Yes 2 0.3 NO 2.7 Salisbury Background (Salisbury) DT62 Exeter Street - Roadside 414547 129575 NO2 Yes 8 2.5 YES 2 colocation, (Salisbury) Salisbury DT63 Exeter Street - Roadside 414547 129575 NO2 Yes 8 2.5 YES 2 colocation, (Salisbury) Salisbury DT64 Exeter Street - Roadside 414547 129575 NO2 Yes 8 2.5 YES 2 colocation, (Salisbury) Salisbury DT65 17 Wilton Roadside 413690 130362 NO2 Yes (Wilton 0 1.5 NO 2.7 Road, Road) Salisbury
LAQM Annual Status Report 2021 23 Wiltshire Council
Diffusion Site Name Site Type X OS Grid Y OS Grid Pollutants In AQMA? Distance to Tube Co- Tube Distance to Tube ID Ref Ref Monitored Which AQMA? kerb of located with Height Relevant (Easting) (Northing) nearest a (m) Exposure road (m) (2) Continuous (m) (1) Analyser? DT66 31 Devizes Roadside 413669 130503 NO2 No 0 0.5 NO 2.6 Road, Salisbury DT67 91 Exeter St, Roadside 414550 129523 NO2 Yes 2 0.4 NO 3 Salisbury (Salisbury) DT68 Catherine St, Roadside 414551 129815 NO2 Yes 0 1.05 NO 2.4 Salisbury (Salisbury) DT69 3 Wheelwright Roadside 417055 121502 NO2 No 0 1.2 NO 2.4 Mews, Downton DT70 161 Castle St, Roadside 414312 130651 NO2 Yes 0 1.75 NO 2.7 Salisbury (Salisbury) DT71 225 Wilton Rd, Roadside 412572 130673 NO2 Yes (Wilton 0 1.8 NO 2.7 Salisbury Road) DT72 107 Wilton Rd, Roadside 413038 130526 NO2 Yes (Wilton 0 2.6 NO 2 Salisbury Road) DT73 99 Devizes Rd, Roadside 413517 130698 NO2 No 0 4.7 NO 2.65 Salisbury DT74 37 Castle Roadside 414320 130879 NO2 Yes 0 7.95 NO 2.5 Road, (Salisbury) Salisbury DT75 12 West Street, Roadside 409600 131236 NO2 No 0 1.9 NO 2.5 Wilton DT76 3 Church Road Roadside 415987 130940 NO2 No 0 2.65 NO 2.5 Laverstock Notes: (1) 0m if the monitoring site is at a location of exposure (e.g. installed on the façade of a residential property). (2) N/A if not applicable.
LAQM Annual Status Report 2021 24 Wiltshire Council
3 Table A.3 – Annual Mean NO2 Monitoring Results: Automatic Monitoring (µg/m ) Site ID X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) AM1 414547 129575 Roadside 99.61 35 35 35 30 26 AM2 382533 161115 Roadside 97.28 37 35 31 31 25 AM3 400765 161458 Roadside 99.01 31 42 41 37 29 AM4 406888 182711 Roadside 99.7 n/a n/a 30 30 26
☒ Reported concentrations are those at the location of the monitoring site (annualised, as required), i.e. prior to any fall-off with distance correction Notes: The annual mean concentrations are presented as µg/m3. 3 Exceedances of the NO2 annual mean objective of 40µg/m are shown in bold. Concentrations are those at the location of monitoring and not those following any fall-off with distance adjustment. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 25 Wiltshire Council
3 Table A.4 – Annual Mean NO2 Monitoring Results: Non-Automatic Monitoring (µg/m ) Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 1 400000 161109 Urban Background 100 100.0 8.6 7.1
2 399924 161729 Roadside 100 100.0 44.1 39.3 41.7 38.2 31.6
3 399763 161717 Kerbside 100 100.0 45.4 38.9 43.7 38.3 31.6
4 400210 161623 Roadside 92.3 92.3 43.6 39.8 42.1 40.3 30.9
5 401778 162414 Roadside 100 100.0 17.9 16.5
6 400635 160982 Roadside 100 100.0 38.4 34.6 38.7 35.5 28.2
7 400807 161389 Roadside 82.7 82.7 41.3 34.9 37.6 34.9 29.8
8 416230 160122 Urban Background 90 75.0 8.1 6.2
9 386131 157761 Roadside 92.3 92.3 20.6 18.2
10 418942 169384 Roadside 100 100.0 51.9 44.6 50.4 47.3 37.8
11 418944 169702 Suburban 100 100.0 13.3 9.3
12 418053 169224 Roadside 100 100.0 42.6 34.9 41.8 37.3 25.3
LAQM Annual Status Report 2021 26 Wiltshire Council
Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 13 419296 168760 Roadside 100 100.0 43.4 35.4 36.6 30.8 24.0
14 419011 169012 Urban Background 100 100.0 11.4 11.7 11.2
15 419152 169083 Roadside 100 100.0 41.4 34.8 35.9 33.9 25.2
16 423535 149822 Roadside 100 100.0 10.5 8.9
17 426941 150795 Roadside 100 100.0 10.0 8.1
18 400126 170745 Urban Background 90.4 90.4 9.9 9.3 7.8
19 399873 170737 Roadside 92.3 92.3 55.0 48.3 54.9 48.7 40.8
20 399988 170587 Roadside 100 100.0 34.4 27.9 32.8 27.8 23.4
21 399657 171164 Roadside 100 100.0 30.9 26.7 29.5 23.8 19.5
22 391647 174766 Roadside 100 100.0 12.5 10.6
23 390446 172480 Roadside 100 100.0 15.4 13.2
24 391712 173286 Roadside 100 100.0 43.5 26.7 31.0 27.4 23.7
25 390454 174047 Roadside 100 100.0 13.4 11.7
26 392467 122055 Urban Background 100 100.0 12.1 9.7 8.5
LAQM Annual Status Report 2021 27 Wiltshire Council
Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 27 391925 173579 Roadside 100 100.0 37.2 31.8 26.3
28 387240 151163 Roadside 100 100.0 44.7 32.7 41.0 35.0 29.9
29 387166 150899 Roadside 100 100.0 49.1 40.1 48.7 42.1 36.3
30 387269 151507 Roadside 90.4 90.4 35.9 29.0 32.5 27.9 25.1
31 386491 151580 Roadside 100 100.0 17.5 16.3 13.7
32 386739 150091 Suburban 100 100.0 11.1 9.8 8.3
33 382716 161228 Roadside 100 100.0 65.4 55.4 64.3 54.7 51.2
34 382538 161122 Roadside 92.3 92.3 31.4 25.7 31.2 27.7 23.0
35 382538 161122 Roadside 100 100.0 31.2 24.5 30.8 27.7 23.1
36 382538 161122 Roadside 100 100.0 31.2 25.6 31.1 28.0 23.4
37 382544 161085 Kerbside 100 100.0 47.7 41.8 50.6 44.4 36.6
38 381878 160836 Urban Background 100 100.0 8.4 9.5 6.4
39 393354 188636 Roadside 92.3 92.3 11.2 8.0
40 392312 187507 Roadside 100 100.0 10.2 8.0
LAQM Annual Status Report 2021 28 Wiltshire Council
Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 41 406944 182792 Roadside 92.3 92.3 44.1 35.2 39.6 34.1 29.7
42 390118 164878 Roadside 100 100.0 41.8 38.6 37.4 32.9 27.0
43 390136 164277 Roadside 100 100.0 16.0 13.7
44 390417 164799 Roadside 100 100.0 19.8 16.3
45 384343 157806 Urban Background 90.4 90.4 11.4 10.3 8.2
46 385244 157541 Kerbside 100 100.0 37.5 33.1 31.4 28.9 24.4
47 388678 144847 Roadside 84.6 84.6 10.7 9.5
48a 390387 166196 Kerbside 92.3 92.3 14.7
49 383812 155257 Roadside 100 100.0 21.8 17.3 14.2
50 382595 168543 Roadside 100 100.0 16.5 13.4
51 386577 170652 Urban Background 100 100.0 12.3 10.2 9.1
52 415105 130641 Roadside 100 100.0 43.4 34.5 40.1 35.7 29.8
53 414373 129979 Kerbside 100 100.0 41.2 35.2 42.7 36.7 29.6
54 414682 129425 Roadside 100 100.0 15.1 12.2
LAQM Annual Status Report 2021 29 Wiltshire Council
Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 55 414500 130105 Roadside 100 100.0 34.4 30.9 40.9 33.9 21.1
56 414602 130054 Roadside 100 100.0 33.2 28.9 33.5 29.7 24.1
57 412872 130679 Roadside 100 100.0 14.3 11.7
58 410231 131553 Roadside 100 100.0 12.0 9.1
59 413828 130142 Roadside 90.4 90.4 47.5 41.3 50.6 43.6 33.0
60 416641 140766 Roadside 100 100.0 11.3 9.6
61 414760 130567 Urban Background 100 100.0 22.0 17.8 19.3 16.1 12.8
62 414547 129575 Roadside 100 100.0 37.0 30.4 34.8 30.0 26.8
63 414547 129575 Roadside 100 100.0 37.7 31.1 34.9 29.6 26.7
64 414547 129575 Roadside 100 100.0 37.4 31.3 35.0 29.8 27.1
65 413690 130362 Roadside 100 100.0 58.4 46.2 57.9 51.3 45.7
66 413669 130503 Roadside 100 100.0 41.3 36.6 40.9 37.1 32.4
67 414550 129523 Roadside 100 100.0 43.9 33.8 42.6 34.8 27.3
68 414551 129815 Roadside 100 100.0 38.9 31.1 40.9 35.5 26.4
LAQM Annual Status Report 2021 30 Wiltshire Council
Diffusion X OS Grid Y OS Grid Site Type Valid Data Capture Valid Data Capture 2016 2017 2018 2019 2020 Tube ID Ref Ref for Monitoring Period 2020 (%) (2) (Easting) (Northing) (%) (1) 69 417055 121502 Roadside 100 100.0 11.7 10.6
70 414312 130651 Roadside 100 100.0 41.0 32.6 41.3 36.2 30.1
71 412572 130673 Roadside 100 100.0 44.6 37.0 45.8 38.7 32.4
72 413038 130526 Roadside 100 100.0 37.3 30.7 37.9 31.6 25.9
73 413517 130698 Roadside 100 100.0 32.4 27.9 32.1 28.9 25.0
74 414320 130879 Roadside 100 100.0 27.8 34.8 28.4 24.6
75 409600 131236 Roadside 100 100.0 32.9 24.9 33.6 27.4 21.0
76 415987 130940 Roadside 100 100.0 19.9 22.0 19.5 16.3
☒ Annualisation has been conducted where data capture is <75% and >33% in line with LAQM. ☒ Diffusion tube data has been bias adjusted. ☒ Reported concentrations are those at the location of the monitoring site (bias adjusted and annualised, as required), i.e. prior to any fall-off with distance correction. Notes: The annual mean concentrations are presented as µg/m3. 3 Exceedances of the NO2 annual mean objective of 40µg/m are shown in bold. 3 NO2 annual means exceeding 60µg/m , indicating a potential exceedance of the NO2 1-hour mean objective are shown in bold and underlined.
LAQM Annual Status Report 2021 31 Wiltshire Council
Means for diffusion tubes have been corrected for bias. All means have been “annualised” as per LAQM.TG16 if valid data capture for the full calendar year is less than 75%. See Appendix C for details. Concentrations are those at the location of monitoring and not those following any fall-off with distance adjustment. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 32 Wiltshire Council
Figure A.1 – Trends in Annual Mean NO2 Concentrations
Bradford on Avon nitrogen dioxide annual mean results 2015 to 2020.
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Masons Lane Market Street Objective
LAQM Annual Status Report 2021 33 Wiltshire Council
Calne annual mean nitrogen dioxide monitoring results: 2015-2020 60
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34 New Road, Calne (King George) 30 London Road, Calne 57 Curzon St, Calne objective
LAQM Annual Status Report 2021 34 Wiltshire Council
Devizes annual mean nitrogen dioxide monitoring results 2015 & 2020 50
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30 ug/m3
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Shanes Castle The Nursery Opp Wadworths St James Place Southgate Objective
LAQM Annual Status Report 2021 35 Wiltshire Council
Marlborough annual mean nitrogen dioxide results 2015 to 2020
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Salisbury Road Herd Street London Road Objective Barn Street
LAQM Annual Status Report 2021 36 Wiltshire Council
Salisbury Wilton Road (A36(T)) annual mean nitrogen dioxide monitoring results 2015-2020.
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17 Wilton Road 225 Wilton Road Objective 107 Wilton Road
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Salisbury city centre (1) annual mean nitrogen dioxide results 2015-2020
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Winchester Street 91 Exeter Street Objective
LAQM Annual Status Report 2021 38 Wiltshire Council
Salisbury city centre (2) annual mean nitrogen dioxide results 2015-2020.
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123 South Western Road Minster Street Objective
LAQM Annual Status Report 2021 39 Wiltshire Council
Salisbury (Devizes Road and Castle Road) annual mean nitrogen dioxide results 2015-2020
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31 Devizes Road 37 Castle Road Objective
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Westbury annual mean nitrogen dioxide results 2015- 2020 60
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Haynes Rd Warminster Rd Objective
LAQM Annual Status Report 2021 41 Wiltshire Council
3 Table A.5 – 1-Hour Mean NO2 Monitoring Results, Number of 1-Hour Means > 200µg/m
Site ID X OS Y OS Grid Site Type Valid Data Capture Valid Data 2016 2017 2018 2019 2020 Grid Ref Ref for Monitoring Capture 2020 (Easting) (Northing) Period (%) (1) (%) (2) AM1 414547 129575 Roadside 99.61 0 0 0 0 0 AM2 382533 161115 Roadside 97.28 0 0 3 0 0 AM3 400765 161458 Roadside 99.01 1 7 2 1 0 AM4 406888 182711 Roadside 99.7 n/a n/a 0 0 0
Notes: Results are presented as the number of 1-hour periods where concentrations greater than 200µg/m3 have been recorded. 3 Exceedances of the NO2 1-hour mean objective (200µg/m not to be exceeded more than 18 times/year) are shown in bold. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 42 Wiltshire Council
3 Table A.6 – Annual Mean PM10 Monitoring Results (µg/m )
Site ID X OS Y OS Grid Site Type Valid Data Capture Valid Data 2016 2017 2018 2019 2020 Grid Ref Ref for Monitoring Capture 2020 (Easting) (Northing) Period (%) (1) (%) (2) AM1 414547 129575 Roadside 94.16 14 20 22 22 21 AM2 382533 161115 Roadside 94.84 27 24 24 23 18 AM3 400765 161458 Roadside 92.77 20 20 20 21 19 Notes: The annual mean concentrations are presented as µg/m3. 3 Exceedances of the PM10 annual mean objective of 40µg/m are shown in bold. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 43 Wiltshire Council
Figure A.2 – Trends in Annual Mean PM10 Concentrations
Annual PM10 monitoring from real time analysers 45
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0 2016 2017 2018 2019 2020
AM1 - Salisbury auto AM3 - Devizes auto AM2 - BOA Objective
LAQM Annual Status Report 2021 44 Wiltshire Council
3 Table A.7 – 24-Hour Mean PM10 Monitoring Results, Number of PM10 24-Hour Means > 50µg/m
Site ID X OS Y OS Grid Site Type Valid Data Capture Valid Data 2016 2017 2018 2019 2020 Grid Ref Ref for Monitoring Capture 2020 (Easting) (Northing) Period (%) (1) (%) (2) AM1 414547 129575 Roadside 94.16 1 1 0 5 0 AM2 382533 161115 Roadside 94.84 8 15 0 5 0 AM3 400765 161458 Roadside 92.77 1 1 0 8 3
Notes: Results are presented as the number of 24-hour periods where daily mean concentrations greater than 50µg/m3 have been recorded. 3 Exceedances of the PM10 24-hour mean objective (50µg/m not to be exceeded more than 35 times/year) are shown in bold. If the period of valid data is less than 85%, the 90.4th percentile of 24-hour means is provided in brackets. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 45 Wiltshire Council
3 Table A.8 – Annual Mean PM2.5 Monitoring Results (µg/m )
Site ID X OS Y OS Grid Site Type Valid Data Capture Valid Data 2016 2017 2018 2019 2020 Grid Ref Ref for Monitoring Capture 2020 (Easting) (Northing) Period (%) (1) (%) (2) AM1 414547 129575 Roadside 94.16 9.8 14 15.4 15.4 14.7 AM2 382533 161115 Roadside 94.84 18.9 16.8 16.8 16.1 12.6 AM3 400765 161458 Roadside 92.77 14 14 14 14.7 13.3 Notes: The annual mean concentrations are presented as µg/m3. All means have been “annualised” as per LAQM.TG16 if valid data capture for the full calendar year is less than 75%. See Appendix C for details. (1) Data capture for the monitoring period, in cases where monitoring was only carried out for part of the year. (2) Data capture for the full calendar year (e.g. if monitoring was carried out for 6 months, the maximum data capture for the full calendar year is 50%).
LAQM Annual Status Report 2021 46 Wiltshire Council
Appendix B: Full Monthly Diffusion Tube Results for 2020
3 Table B.1 – NO2 2020 Diffusion Tube Results (µg/m )
DT ID X OS Y OS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean: Annual Mean: Annual Mean: Grid Ref Grid Ref Raw Data Annualised and Distance (Easting) (Easting) Bias Adjusted Corrected to (0.91) Nearest Exposure 1 400000 161109 11.7 5.2 8.0 8.0 4.5 5.5 3.2 6.3 6.8 6.9 16.1 11.4 7.8 7.1
2 399924 161729 56.6 37.6 27.6 27.6 21.8 27.6 24.9 33.1 36.5 39.2 42.6 42.8 34.8 31.6
3 399763 161717 50.1 34.3 28.7 28.7 26.8 26.4 30.6 39.2 41.0 37.1 36.0 38.0 34.7 31.6
4 400210 161623 51.2 26.2 26.2 24.9 30.6 30.3 38.1 36.4 35.8 35.7 38.3 34.0 30.9
5 401778 162414 28.9 18.1 16.2 16.2 14.0 14.4 13.6 17.4 18.3 18.4 22.9 19.9 18.2 16.5
6 400635 160982 46.1 31.4 24.8 24.8 20.1 25.3 26.1 31.3 33.6 35.3 37.8 35.6 31.0 28.2
7 400807 161389 54.1 36.0 24.5 24.5 19.2 23.9 32.2 35.7 38.9 38.8 32.8 29.8
8 416230 160122 4.5 7.6 7.6 5.4 5.0 4.7 6.4 7.8 12.4 6.8 6.2
9 386131 157761 19.6 20.7 20.7 15.3 15.1 10.9 19.1 21.9 20.1 29.3 27.4 20.0 18.2
10 418942 169384 55.4 44.0 31.9 31.9 35.9 36.6 43.4 42.9 40.5 47.2 44.7 44.7 41.6 37.8
11 418944 169702 15.0 10.3 9.2 9.2 5.7 7.0 6.5 7.8 8.2 10.4 19.9 14.0 10.3 9.3
12 418053 169224 36.5 28.9 10.1 10.1 31.5 25.7 22.8 31.7 33.0 31.5 37.5 34.7 27.8 25.3
13 419296 168760 39.9 35.8 22.8 22.8 21.3 5.3 28.2 28.8 10.0 36.0 35.7 30.3 26.4 24.0
14 419011 169012 12.4 8.7 8.9 8.9 5.0 25.7 4.4 6.6 30.7 8.0 17.1 11.6 12.3 11.2
15 419152 169083 27.1 39.1 22.3 22.3 19.4 23.0 26.3 26.2 28.5 32.1 35.2 31.5 27.8 25.2
16 423535 149822 11.9 8.8 9.4 9.4 5.0 8.8 5.9 7.8 9.0 10.8 15.9 14.3 9.8 8.9
17 426941 150795 12.3 9.8 8.4 8.4 4.2 6.3 4.9 5.9 8.1 9.6 15.8 13.2 8.9 8.1
18 400126 170745 11.3 9.4 6.7 6.7 5.9 5.3 5.2 7.4 9.9 13.9 12.3 8.5 7.8
LAQM Annual Status Report 2021 47 Wiltshire Council
DT ID X OS Y OS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean: Annual Mean: Annual Mean: Grid Ref Grid Ref Raw Data Annualised and Distance (Easting) (Easting) Bias Adjusted Corrected to (0.91) Nearest Exposure 19 399873 170737 47.4 50.7 37.2 37.2 33.2 40.6 40.3 38.9 54.4 56.1 58.0 44.9 40.8
20 399988 170587 28.3 23.8 25.0 25.0 22.6 20.3 19.4 24.0 25.6 27.1 35.0 32.2 25.7 23.4
21 399657 171164 25.5 21.8 20.3 20.3 18.3 17.0 13.0 18.1 21.8 22.5 30.4 28.3 21.4 19.5
22 391647 174766 18.3 14.7 9.6 9.6 5.6 6.2 6.8 8.5 10.7 11.0 20.3 19.1 11.7 10.6
23 390446 172480 22.1 18.5 11.9 11.9 7.1 9.1 8.1 10.9 12.3 13.9 25.8 22.2 14.5 13.2
24 391712 173286 31.4 29.4 21.1 21.1 19.0 22.3 21.5 27.9 28.6 30.3 29.2 31.8 26.1 23.7
25 390454 174047 20.4 12.9 11.3 11.3 7.9 8.1 6.9 10.0 13.0 12.5 21.9 18.7 12.9 11.7
26 392467 122055 14.6 9.9 8.1 8.1 3.5 6.1 5.7 7.1 9.3 9.0 15.1 15.4 9.3 8.5
27 391925 173579 36.9 35.2 25.8 25.8 20.4 21.3 24.7 27.4 31.5 32.0 32.8 34.1 29.0 26.3
28 387240 151163 42.3 17.5 34.0 34.0 32.7 31.8 23.2 37.8 33.4 32.2 39.7 36.9 32.9 29.9
29 387166 150899 52.5 32.9 38.8 38.8 33.5 40.1 29.9 45.5 36.1 41.5 44.6 44.8 39.9 36.3
30 387269 151507 46.1 25.5 22.2 22.2 20.4 24.5 16.7 28.8 29.9 29.6 37.5 - 27.6 25.1
31 386491 151580 23.3 13.8 14.1 14.1 11.1 11.1 10.7 13.1 16.8 14.8 20.3 18.0 15.1 13.7
32 386739 150091 14.2 5.2 9.7 9.7 5.9 6.2 5.3 8.1 9.4 8.5 15.0 12.3 9.1 8.3
33 382716 161228 71.1 52.9 47.2 47.2 38.6 41.8 46.8 60.8 66.7 70.8 70.2 61.4 56.3 51.2 45.8
34 382538 161122 24.1 22.2 22.2 21.5 22.0 20.7 31.2 29.3 29.9 26.4 29.1 25.3 23.0
35 382538 161122 31.1 22.1 21.8 21.8 21.9 21.3 20.6 31.1 28.5 29.6 26.4 28.4 25.4 23.1
36 382538 161122 33.4 22.3 21.7 21.7 23.8 21.6 20.4 29.7 28.9 29.9 26.6 28.4 25.7 23.4
37 382544 161085 54.1 43.7 37.1 37.1 29.0 38.7 35.2 48.1 38.1 40.3 39.0 43.0 40.3 36.6
38 381878 160836 10.8 4.3 4.6 4.6 4.5 5.0 4.3 7.4 7.1 7.2 13.5 10.7 7.0 6.4
39 393354 188636 12.3 10.3 4.9 4.9 4.9 4.6 6.8 9.4 8.6 16.5 13.3 8.8 8.0
LAQM Annual Status Report 2021 48 Wiltshire Council
DT ID X OS Y OS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean: Annual Mean: Annual Mean: Grid Ref Grid Ref Raw Data Annualised and Distance (Easting) (Easting) Bias Adjusted Corrected to (0.91) Nearest Exposure 40 392312 187507 13.2 8.7 7.9 7.9 5.2 4.8 5.0 7.1 9.5 6.5 15.4 14.2 8.8 8.0
41 406944 182792 42.7 34.9 27.5 27.5 23.8 29.8 28.0 38.2 36.8 37.8 32.4 32.7 29.7
42 390118 164878 43.7 29.1 22.5 22.5 18.6 24.9 23.5 32.3 32.0 36.6 36.9 33.3 29.6 27.0
43 390136 164277 21.1 16.7 10.7 10.7 7.6 13.4 10.4 12.7 14.9 16.6 24.5 21.7 15.1 13.7
44 390417 164799 23.2 16.5 18.5 18.5 12.7 8.8 10.9 17.5 19.1 18.8 26.9 23.6 17.9 16.3
45 384343 157806 13.5 7.4 8.6 8.6 - 5.7 3.8 7.5 7.9 7.3 15.2 13.6 9.0 8.2
46 385244 157541 41.4 28.9 20.3 20.3 15.8 20.4 21.6 25.6 29.3 28.8 35.0 34.1 26.8 24.4
47 388678 144847 11.1 11.1 6.2 6.3 7.6 8.5 11.8 10.4 16.4 15.1 10.4 9.5
48a 390387 166196 6.1 14.8 14.8 11.3 14.8 9.3 18.9 19.2 21.7 24.3 23.0 16.2 14.7
49 383812 155257 23.2 11.3 15.0 15.0 10.0 12.5 10.6 15.3 17.1 14.9 22.5 20.5 15.7 14.2
50 382595 168543 20.9 17.2 12.4 12.4 9.2 10.6 11.2 13.0 15.2 15.1 19.7 20.6 14.8 13.4
51 386577 170652 16.8 11.0 8.2 8.2 5.5 5.6 5.7 7.4 9.4 9.6 16.1 16.2 10.0 9.1
52 415105 130641 35.8 36.9 29.0 29.0 21.4 26.0 29.5 35.5 33.1 41.4 37.2 38.5 32.8 29.8
53 414373 129979 28.6 30.6 33.5 33.5 25.6 25.5 29.9 36.7 40.5 39.6 31.6 35.8 32.6 29.6
54 414682 129425 15.7 14.2 12.3 12.3 7.0 10.8 7.4 12.4 14.4 15.1 19.4 19.4 13.4 12.2
55 414500 130105 18.5 23.6 22.1 22.1 15.6 21.1 16.5 24.4 27.2 29.3 28.8 29.2 23.2 21.1
56 414602 130054 22.9 30.2 22.4 22.4 15.7 26.0 19.6 30.9 29.9 34.3 30.7 33.5 26.6 24.1
57 412872 130679 15.4 10.0 13.8 13.8 8.0 11.2 7.2 8.5 13.1 14.4 19.5 19.0 12.8 11.7
58 410231 131553 10.1 7.5 10.8 10.8 6.9 9.0 5.3 9.9 11.1 11.2 13.5 13.9 10.0 9.1
59 413828 130142 35.6 46.6 30.5 30.5 33.2 31.4 30.8 39.4 41.1 - 44.6 35.4 36.3 33.0
60 416641 140766 11.6 7.7 11.6 11.6 6.7 7.3 6.1 9.1 10.6 11.3 17.3 16.3 10.6 9.6
LAQM Annual Status Report 2021 49 Wiltshire Council
DT ID X OS Y OS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean: Annual Mean: Annual Mean: Grid Ref Grid Ref Raw Data Annualised and Distance (Easting) (Easting) Bias Adjusted Corrected to (0.91) Nearest Exposure 61 414760 130567 15.9 14.1 12.9 12.9 6.9 10.8 9.0 12.4 14.9 16.3 22.1 21.4 14.1 12.8
62 414547 129575 20.6 29.9 26.7 26.7 20.9 23.7 23.9 29.3 32.3 39.5 38.2 42.5 29.5 26.8
63 414547 129575 21.2 30.1 26.7 26.7 20.3 23.7 22.4 30.6 35.5 38.5 37.0 39.7 29.4 26.7
64 414547 129575 29.2 30.7 26.7 26.7 20.8 22.9 23.2 29.3 33.6 37.5 37.5 38.9 29.8 27.1
65 413690 130362 48.4 55.6 43.3 43.3 25.3 51.1 44.3 58.3 58.6 58.4 55.9 60.5 50.2 45.7
66 413669 130503 40.0 41.4 29.2 29.2 21.6 35.3 27.2 34.7 40.3 39.2 43.0 46.2 35.6 32.4
67 414550 129523 27.8 25.6 32.6 32.6 25.1 29.2 18.9 37.3 35.9 28.7 33.0 34.5 30.1 27.3
68 414551 129815 25.5 26.4 28.4 28.4 20.4 30.9 18.3 37.0 28.3 31.4 32.4 40.7 29.0 26.4
69 417055 121502 14.6 8.3 12.1 12.1 8.2 10.3 5.5 12.3 11.1 10.4 16.8 17.8 11.6 10.6
70 414312 130651 38.4 36.9 29.6 29.6 21.5 27.6 29.6 34.3 36.3 38.5 35.0 39.9 33.1 30.1
71 412572 130673 39.7 33.0 28.7 28.7 23.5 34.8 28.3 39.8 44.2 41.8 44.9 39.9 35.6 32.4
72 413038 130526 26.5 28.9 29.2 29.2 22.1 28.4 20.4 17.4 36.2 29.5 37.4 36.3 28.5 25.9
73 413517 130698 27.1 31.9 24.0 24.0 17.1 28.8 21.0 29.4 28.8 31.9 34.3 31.7 27.5 25.0
74 414320 130879 25.3 27.9 26.0 26.0 20.2 25.4 21.0 29.7 26.2 30.3 33.2 32.8 27.0 24.6
75 409600 131236 20.6 20.5 22.1 22.1 17.1 22.1 13.6 25.2 27.7 24.3 31.1 30.8 23.1 21.0
76 415987 130940 21.1 24.4 16.4 16.4 9.2 13.3 11.9 14.1 18.2 22.3 24.8 23.5 17.9 16.3
☒ All erroneous data has been removed from the NO2 diffusion tube dataset presented in Table B.1. ☒ Annualisation has been conducted where data capture is <75% and >33% in line with LAQM.TG16. ☒ Local bias adjustment factor used. ☒ Where applicable, data has been distance corrected for relevant exposure in the final column. ☒ Wiltshire Council confirm that all 2020 diffusion tube data has been uploaded to the Diffusion Tube Data Entry System. Notes: 3 Exceedances of the NO2 annual mean objective of 40µg/m are shown in bold. See Appendix C for details on bias adjustment and annualisation.
LAQM Annual Status Report 2021 50 Wiltshire Council
Appendix C: Supporting Technical Information / Air Quality Monitoring Data QA/QC
New or Changed Sources Identified Within Wiltshire Council During 2020
Wiltshire Council has not identified any new sources relating to air quality within the reporting year of 2020. A planning application for a waste to energy incinerator in Westbury is likely to be determined in 2021.
Additional Air Quality Works Undertaken by Wiltshire Council during 2020
A comprehensive study of traffic volumes, speeds and air quality from several roads in Bradford on Avon has been undertaken following the implementation of a trial one-way system. Work is underway to compare these data against the baseline, pre-pandemic figures. We will be drawing on this evidence base as part of our work in relation to our new Air Quality Action Plan for the county.
QA/QC of Diffusion Tube Monitoring
Wiltshire Council used tubes supplied by Somerset Scientific Services for the diffusion tube monitoring carried out in 2020. Tubes were analysed using a solution of 20% TEA in water and following a method based on the ‘Diffusion Tube for Ambient NO2 Monitoring: Practical Guidance’. The lab has confirmed to us that they participated in 3 rounds of the AIR-PT analysis scheme and all results were satisfactory.
Monitoring was largely completed in adherence with the 2020 Diffusion Tube Monitoring Calendar although the tubes set out in April also had to cover May as we were unable to change them and the lab was closed. The results were averaged for this period in accordance with the DEFRA Covid 19: Supplementary Guidance.
LAQM Annual Status Report 2021 51 Wiltshire Council
Diffusion Tube Annualisation
All diffusion tube monitoring locations within Wiltshire Council recorded data capture of 75% therefore it was not required to annualise any monitoring data.
Diffusion Tube Bias Adjustment Factors
The diffusion tube data presented within the 2021 ASR have been corrected for bias using an adjustment factor. Bias represents the overall tendency of the diffusion tubes to under or over-read relative to the reference chemiluminescence analyser. LAQM.TG16 provides guidance about the application of a bias adjustment factor to correct diffusion tube monitoring. Triplicate co-location studies can be used to determine a local bias factor based on the comparison of diffusion tube results with data taken from NOx/NO2 continuous analysers. Alternatively, the national database of diffusion tube co-location surveys provides bias factors for the relevant laboratory and preparation method.
The national database of diffusion tube bias factors (version 03/21) provided a bias correction factor of 0.76 for tubes analysed by Somerset Scientific Services using the 20%TEA in water method. However, this was only based upon 2 studies.
As such, Wiltshire Council decided to apply a locally calculated bias adjustment factor of 0.91 to the 2020 monitoring data to provide a more conservative and locally relevant correction. A summary of bias adjustment factors used by Wiltshire Council over the past five years is presented in Table C.1.
Wiltshire Council co-locate 3 diffusion tubes with 2 real time analysers in Bradford on Avon and Salisbury in order that a local bias adjustment factor can be calculated. All details are presented in Table C.2.
Table C.1 – Bias Adjustment Factor
Year Local or National If National, Version of Adjustment Factor National Spreadsheet
2020 Local - 0.91
2019 National 03/21 0.83
2018 National 03/21 0.91
2017 National 03/21 0.77
2016 National 03/21 0.88
LAQM Annual Status Report 2021 52 Wiltshire Council
NO2 Fall-off with Distance from the Road
Wherever possible, local authorities should ensure that monitoring locations are representative of exposure. However, where this is not possible, the NO2 concentration at the nearest location relevant for exposure should be estimated using the Diffusion Tube
Data Processing Tool/NO2 fall-off with distance calculator available on the LAQM Support website. Where appropriate, non-automatic annual mean NO2 concentrations corrected for distance are presented in Table B.1.
A fall off for distance calculation was required for one diffusion tube site; site reference 33 located in Masons Lane, Bradford on Avon. This is presented in Table C.4.
QA/QC of Automatic Monitoring
Automatic calibration
To ensure that the information obtained from the analysers is as accurate as possible and to quantify any instrument drifts a stringent QA/QC protocol is followed.
The API M200A analyser is subjected to daily automatic calibration. This provides a daily check on the performance of the instrument. It should be noted that these results are not used for instrument scaling.
The zero air is generated by passing ambient air through purafil charcoal scrubbers before it is passed into the reaction cell. The span gas is generated by an NO2 permeation tube containing pure liquid NO2. The permeation tube is enclosed in an oven, which is maintained at a constant temperature. The zero air is passed across the permeation tube at a constant flow rate. Provided the flow rate and temperature are kept constant, the amount of NO2 permeating from the tube into the air stream will be constant. The gas then produced then passes into the reaction cell and a span calibration response is determined.
The data is collected as 1-hour averages. The data is uploaded from the analyser via modem to the AQA-Ricardo team who check scale and publish the data on the website; http://www.wiltshireairquality.org.uk/
Manual calibration
Every three to four weeks manual calibration checks are carried out on the API M2000 analysers. This allows the instrument drifts to be fully qualified and documented using traceable calibration gas standards and the results are used to scale data.
LAQM Annual Status Report 2021 53 Wiltshire Council
At the time of the instrument calibration checks, instrument pre-calibration checks are made to ensure that the condition of the analyser, before the calibration check, is assessed and any faults attended to.
The calibration procedure requires a zero check on the analyser. This is achieved by a source of zero air being provided by passing ambient air through the charcoal scrubber before it enters the reaction cell. Once stability has been achieved (this is defined as a variation of less than 0.1ppb over a one-minute period for the analyser) three readings are recorded from the instrument display after three ten second intervals. Next the calibration gas bottle is opened at a pressure of 30 psi. The analyser is allowed to stabilise for a minimum of ten minutes. Three consecutive readings are taken from the instrument display, allowing ten seconds between readings. The calibration gas is then isolated.
By considering the previous calibration results and the results obtained from the calibration just performed, the success of the calibration procedure is determined. The zero value should not differ by more than ± 2ppb from the previous calibration. The span calibration should not differ by more than 5% from that obtained during the previous calibration. Additionally, the analyser sample inlet filter is changed when necessary.
Six monthly checks
These checks are carried out by our current contractor, Matts Monitors Limited, at the same time as they service the equipment. They ensure that the measurements from the analyser are representative and inter-comparable. The calibrations act as an independent audit of the system performance. Additionally, any site-specific problems that may have remained undetected will be fully quantified.
All real time monitoring data (live /historic) is available via our dedicated Air Quality website (https://www.wiltshireairquality.org.uk/) and all data presented there and in this report is ratified by Ricardo as discussed.
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PM10 Monitoring Adjustment
Data from Wiltshire Council automatic analysers is handled directly by Ricardo AEA which has confirmed the following:
Bradford on Avon has a factor of 0.8333 applied to it as it has unheated inlet.
Devizes and Salisbury have a factor of 1.3 applied to their data as the inlet is heated.
Automatic Monitoring Annualisation
All automatic monitoring locations within Wiltshire Council recorded data capture of greater than 75% therefore it was not required to annualise any monitoring data.
NO2 Fall-off with Distance from the Road
Wherever possible, local authorities should ensure that monitoring locations are representative of exposure. However, where this is not possible, the NO2 concentration at the nearest location relevant for exposure should be estimated using the NO2 fall-off with distance calculator available on the LAQM Support website. Where appropriate, non- automatic annual mean NO2 concentrations corrected for distance are presented in Table B.1.
No automatic NO2 monitoring locations within Wiltshire Council required distance correction during 2020.
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Table C.2 – Local Bias Adjustment Calculation
Local Bias Adjustment Local Bias Adjustment Input 1 Input 2 Periods used to calculate bias 11 12 Bias Factor A 0.87 (0.8-0.95) Bias Factor B 15% (5%-25%) Diffusion Tube Mean (µg/m3) 26.0 29.6 Mean CV (Precision) 2.5% 4.1% Automatic Mean (µg/m3) 24.7 25.8 Data Capture 99% 100% Adjusted Tube Mean (µg/m3) 26 (24-28) Notes: A combined local bias adjustment factor of 0.91 has been used to bias adjust the 2020 diffusion tube results.
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3 Table C.3 – NO2 Fall off With Distance Calculations (concentrations presented in µg/m )
Site Distance (m): Distance (m): Monitored Background Concentration Comments ID Monitoring Site Receptor to Concentration Concentratio Predicted at to Kerb Kerb (Annualised and n Receptor Bias Adjusted 33 1.4 2.4 51.2 6.4 45.8 Predicted concentration at Receptor above AQS objective.
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Appendix D: Map(s) of Monitoring Locations and AQMAs
Figure D.1 – Map of Non-Automatic Monitoring Site
Devizes – Non-Automatic and Automatic Monitoring sites with AQMA.
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Marlborough – Non-Automatic Monitoring sites with AQMA
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Calne – Non-Automatic Monitoring sites with AQMA
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Chippenham – Non-Automatic Monitoring sites
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Westbury – Non-Automatic Monitoring sites with AQMA
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Bradford on Avon – Non-Automatic and Automatic Monitoring sites with AQMA
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Salisbury City Centre (North) – Non-Automatic Monitoring sites with AQMA
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Salisbury City Centre (South) - Non-Automatic & Automatic sites with AQMAs
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Malmesbury – Non-Automatic Monitoring sites
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Melksham – Non-Automatic Monitoring sites
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© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
Trowbridge / Southwick – Non-Automatic Monitoring sites
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© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
Warminster – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Box – Non-Automatic Monitoring site
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© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
Corsham – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Beanacre – Non-Automatic Monitoring site
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© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
Tidworth – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Ludgershall – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Pewsey – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Wilton – Non-Automatic Monitoring sites
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Laverstock – Non-Automatic Monitoring site
© Crown copyright and Database Rights 2020 Ordnance Survey 100049050
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Appendix E: Summary of Air Quality Objectives in England
Table E.1 – Air Quality Objectives in England7
Pollutant Air Quality Objective: Concentration Air Quality Objective: Measured as
3 Nitrogen Dioxide (NO2) 200µg/m not to be exceeded more than 18 times a year 1-hour mean
3 Nitrogen Dioxide (NO2) 40µg/m Annual mean
Particulate Matter 50µg/m3, not to be exceeded more than 35 times a year 24-hour mean (PM10)
Particulate Matter 40µg/m3 Annual mean (PM10)
3 Sulphur Dioxide (SO2) 350µg/m , not to be exceeded more than 24 times a year 1-hour mean
3 Sulphur Dioxide (SO2) 125µg/m , not to be exceeded more than 3 times a year 24-hour mean
3 Sulphur Dioxide (SO2) 266µg/m , not to be exceeded more than 35 times a year 15-minute mean
7 The units are in microgrammes of pollutant per cubic metre of air (µg/m3).
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Appendix F: Impact of COVID-19 upon LAQM
COVID-19 has had a significant impact on society. Inevitably, COVID-19 has also had an impact on the environment, with implications to air quality at local, regional and national scales.
COVID-19 has presented various challenges for Local Authorities with respect to undertaking their statutory LAQM duties in the 2021 reporting year. Recognising this, Defra provided various advice updates throughout 2020 to English authorities, particularly concerning the potential disruption to air quality monitoring programmes, implementation of Air Quality Action Plans (AQAPs) and LAQM statutory reporting requirements. Defra has also issued supplementary guidance for LAQM reporting in 2021 to assist local authorities in preparing their 2021 ASR. Where applicable, this advice has been followed.
Despite the challenges that the pandemic has given rise to, the events of 2020 have also provided Local Authorities with an opportunity to quantify the air quality impacts associated with wide-scale and extreme intervention, most notably in relation to emissions of air pollutants arising from road traffic. The vast majority (>95%) of AQMAs declared within the UK are related to road traffic emissions, where attainment of the annual mean objective for nitrogen dioxide (NO2) is considered unlikely. On 23rd March 2020, the UK Government released official guidance advising all members of public to stay at home, with work- related travel only permitted when absolutely necessary. During this initial national lockdown (and to a lesser extent other national and regional lockdowns that followed), marked reductions in vehicle traffic were observed; Department for Transport (DfT) data8 suggests reductions in vehicle traffic of up to 70% were experienced across the UK by mid-April, relative to pre COVID-19 levels.
This reduction in travel in turn gave rise to a change of air pollutant emissions associated with road traffic, i.e. nitrous oxides (NOx), and exhaust and non-exhaust particulates (PM). The Air Quality Expert Group (AQEG)9 has estimated that during the initial lockdown period in 2020, within urbanised areas of the UK reductions in NO2 annual mean concentrations were between 20 and 30% relative to pre-pandemic levels, which
8 Prime Minister’s Office, COVID-19 briefing on the 31st of May 2020
9 Air Quality Expert Group, Estimation of changes in air pollution emissions, concentrations and exposure during the COVID-19 outbreak in the UK, June 2020
LAQM Annual Status Report 2021 79 Wiltshire Council represents an absolute reduction of between 10 to 20µg/m3 if expressed relative to annual mean averages. During this period, changes in PM2.5 concentrations were less marked than those of NO2. PM2.5 concentrations are affected by both local sources and the transport of pollution from wider regions, often from well beyond the UK. Through analysis of AURN monitoring data for 2018-2020, AQEG have detailed that PM2.5 concentrations during the initial lockdown period are of the order 2 to 5µg/m3 lower relative to those that would be expected under business-as-usual conditions.
As restrictions are gradually lifted, the challenge is to understand how these air quality improvements can benefit the long-term health of the population.
Impacts of COVID-19 on Air Quality within Wiltshire Council
The impact of the COVID-19 pandemic resulted in a clear reduction of levels of NO2 concentrations at all diffusion monitoring sites and real time analysers in 2020 relative to 2019. A reduction of between 10 and 20% has been noted at all sites.
The reduction was particularly apparent between April and June of 2020 with a reduction of up to 30% in levels at most diffusion tube monitoring sites.
Opportunities Presented by COVID-19 upon LAQM within Wiltshire Council
• Social Distancing Traffic Measures – In order to accommodate a wider pavement, a trial one-way system has been introduced in Bradford on Avon with through traffic using Masons Lane to head north (some southerly access to side roads) and Springfield / Woolley Street to head south. The scheme had previously been proposed as a solution to poor air quality in areas of the town, approved by a referendum and was fast tracked as part of the Covid 19 measures implemented by the Council. The Council has accumulated a substantial body of data on traffic volumes, speeds and air quality from several roads in the town, and work is underway to compare these against the baseline, pre-pandemic figures. We will be drawing on this evidence base as part of our work in relation to our new Air Quality Action Plan which will assist in providing evidence to support the continuation of the scheme.
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• Temporary Cycle Lanes – Cycle lanes have been introduced into several towns in Wiltshire including Salisbury, Chippenham, Trowbridge, and Bradford on Avon (Winsley Road). • Bonfires – The Council promoted a message on social media/website and in letters to perpetrators that bonfires should not take place during lockdown to protect those self-isolating/shielding.
Challenges and Constraints Imposed by COVID-19 upon LAQM within Wiltshire Council
• Salisbury City Centre Plan - An emergency traffic order was introduced in Salisbury designed to reduce traffic in the city centre. This was a camera-controlled zone with restricted access and instant penalties for entering without proper authority. Residents were exempt as were a number of other drivers such as taxis. The project was to make the city centre easier to cycle and walk around and enhance the city centre economy. The scheme was supported by the city council but was launched on the day of the second lock down and lost support so was withdrawn. There are no plans to reintroduce it, but the vivacity cameras are still in place and we can access the traffic data generated. Medium Impact • The lab used to analyse our diffusion tubes closed during April and early May 2020 which lead to the tubes being exposed for two months. Nitrogen Dioxide levels were averaged over this period in line with guidance. Small Impact • In previous years, a national bias adjustment factor has been utilised to adjust the diffusion tube results for Wiltshire Council as a robust number of co-location studies were available. However, within 2020 there were only 2 co-location studies that were utilised to calculate the national bias factor for the laboratory and preparation method used and so it was decided to use our local bias correction which also offered a more conservative figure (0.91 compared to 0.76 for the national figure). . medium Impact • A revised AQAP is being developed for Wiltshire Council. However, owing to the reallocation of Council resources during 2020, the development and implementation of the AQAP has been delayed. Current estimates are that the revised AQAP will be prepared in and sent out for draft consultation in late 2021. Small Impact
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The impacts as presented above are aligned with the criteria as defined in Table F 1, with professional judgement considered as part of their application.
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Table F 1 – Impact Matrix
Category Impact Rating: None Impact Rating: Small Impact Rating: Medium Impact Rating: High
Automatic Monitoring – Data Capture More than 75% data capture 50 to 75% data capture 25 to 50% data capture Less than 25% data capture (%)
Automatic Monitoring – QA/QC Adherence to requirements as Routine calibrations taken place Routine calibrations taken place Routine calibrations not undertaken Regime defined in LAQM.TG16 frequently but not to normal regime. infrequently and service and within extended period (e.g. 3 to 4 Audits undertaken alongside service maintenance regimes adhered to. No months). Interruption to service and and maintenance programmes audit achieved maintenance regime and no audit achieved
Passive Monitoring – Data Capture More than 75% data capture 50 to 75% data capture 25 to 50% data capture Less than 25% data capture (%)
Passive Monitoring – Bias Adjustment Bias adjustment undertaken as <25% impact on normal number of 25-50% impact on normal number of >50% impact on normal number of Factor normal available bias adjustment colocation available bias adjustment studies available bias adjustment studies studies (2020 vs 2019) (2020 vs 2019) (2020 vs 2019) and/or applied bias adjustment factor studies not considered representative of local regime
Passive Monitoring – Adherence to Defra diffusion tube exposure Tubes left out for two exposure Tubes left out for three exposure Tubes left out for more than three Changeover Dates calendar adhered to periods periods exposure periods
Passive Monitoring – Storage of Tubes stored in accordance with Tubes stored for longer than normal Tubes unable to be stored according Tubes stored for so long that they Tubes laboratory guidance and analysed but adhering to laboratory guidance to be laboratory guidance but were unable to be analysed prior to promptly. analysed prior to expiry date expiry date. Data unable to be used
AQAP – Measure Implementation Unaffected Short delay (<6 months) in Long delay (>6 months) in No progression in development of a development of a new AQAP, but is development of a new AQAP, but is new AQAP on-going on-going
AQAP – New AQAP Development Unaffected Short delay (<6 months) in Long delay (>6 months) in No progression in development of a development of a new AQAP, but is development of a new AQAP, but is new AQAP on-going on-going
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Glossary of Terms
Abbreviation Description
AQAP Air Quality Action Plan - A detailed description of measures, outcomes, achievement dates and implementation methods, showing how the local authority intends to achieve air quality limit values’
AQMA Air Quality Management Area – An area where air pollutant concentrations exceed / are likely to exceed the relevant air quality objectives. AQMAs are declared for specific pollutants and objectives
ASR Annual Status Report
Defra Department for Environment, Food and Rural Affairs
DMRB Design Manual for Roads and Bridges – Air quality screening tool produced by Highways England
EU European Union
FDMS Filter Dynamics Measurement System
LAQM Local Air Quality Management
NO2 Nitrogen Dioxide
NOx Nitrogen Oxides
PM10 Airborne particulate matter with an aerodynamic diameter of 10µm or less
PM2.5 Airborne particulate matter with an aerodynamic diameter of 2.5µm or less
QA/QC Quality Assurance and Quality Control
SO2 Sulphur Dioxide
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References
• Local Air Quality Management Technical Guidance LAQM.TG16. April 2021. Published by Defra in partnership with the Scottish Government, Welsh Assembly Government and Department of the Environment Northern Ireland. • Local Air Quality Management Policy Guidance LAQM.PG16. May 2016. Published by Defra in partnership with the Scottish Government, Welsh Assembly Government and Department of the Environment Northern Ireland.
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