Local air quality management: policy guidance

Updated guidance for local authorities to take account of Environmental Standards Scotland's recommendations to strengthen the local air quality management regime.

3: Review and Assessment

3.1 Annual Progress Report (APR) templates are available on the Defra Report Submission Website. Examples of completed reports are available on the Review and Assessment helpdesk website.

Assessment of monitoring data

3.2 The minimum requirement is to report monitoring data and trends over recent years. It will also prove helpful to project the measured concentrations forward, using the guidance in LAQM.TG (22). This will provide early warning of likely exceedences that may not have been previously identified and also help to gauge progress on when the objectives are likely to be complied with.

3.3 The APR should provide a summary of all available monitoring data in a format suitable for comparison with the air quality objectives. For example, nitrogen dioxide data should be reported as annual mean concentrations, and where possible as the number of exceedences of the 1-hour objective value of 200 μg/m3. Reporting full hourly data, or full monthly data for diffusion tubes, is not necessary.

3.4 To maximise the value of air quality monitoring, careful attention should be paid to the type of equipment used and the locations where the monitors are placed, as well as the QA/QC and data verification procedures. Detailed guidance on these issues is provided in LAQM.TG (22), and reference should be made to this when setting up and operating monitoring equipment. Local authorities should also contact SEPA to discuss suitability of monitoring locations.

Matters to take into account when reporting monitoring data

3.5 When presenting automatic monitoring data, it should be made clear whether the results have been ratified (data should routinely be ratified by April prior to the APR being submitted). Information on data capture should also be provided.

3.6 Where data are available for fewer than nine months, then they should be adjusted to provide an estimate of the annual mean using the procedure set out in LAQM.TG (22) and adjustment factors available on the LAQM Portal.

3.7 To help understand the results, the type of monitoring site should be specified. For roadside sites the distance from the kerb should be provided. For industrial sites the distance to the source(s) should be specified. This information could be provided as an Appendix to the main report.

3.8 Where nitrogen dioxide diffusion tube data are provided, it should be made clear whether the results have been adjusted for laboratory bias. Where they have been adjusted, brief details should be provided of the adjustment factor used and its source. Details should also be provided of the laboratory being used, the tube preparation method and the exposure period.

3.9 Summary information should be provided on QA/QC.

3.10 Where results are presented for new monitoring sites, a description of the sites should be provided. This should include the reason they were set up, e.g. do they represent worst-case relevant exposure locations?

3.11 When describing sites, it should be made clear whether they represent relevant exposure. For instance, if the site is kerbside, it would be appropriate to say that "the nearest relevant exposure is residential properties set back 5 m from the kerb."

3.12 For short-term objectives, e.g. 1-hour for nitrogen dioxide, the results should be presented as number of hours (or 15-mins for sulphur dioxide, or days for PM10) above the objective value. This should only be done where data capture is >90% of a full year. If data capture is <90% or monitoring is for less than a full year, then it is only appropriate to present the results as percentiles. The following percentiles roughly equate to the objectives: 99.8th percentiles for 1 hour nitrogen dioxide; 99.9th percentiles for 15-min sulphur dioxide; 99.7th percentiles for 1 hour sulphur dioxide; 99.2nd percentile for 24-hour sulphur dioxide; and 90th percentile for PM10. Guidance on calculating percentiles is available in LAQM.TG (22).

3.13 When reporting results, a note should be made of any local or transient circumstances that may have affected the results, e.g. construction activities close to a PM10 monitor, or temporary changes in traffic flows during road works.

3.14 Evidence of any trends over recent years (including observations from during the COVID-19 Pandemic) should be reported. Care should be exercised in discussing trends, as changes in concentrations can occur from year-to-year due to weather conditions or local circumstances. It is normal practice to only consider a trend as being significant when five years' worth of data are available, although a longer timescale may be appropriate for some pollutants, e.g. PM10.

Minimum information to be included in the APR

3.15 New Monitoring Results:

  • Present a map showing monitoring locations.
  • Present summary tables of concentrations of regulated pollutants in a format to allow comparison with the objectives.
  • Provide plots of summary data to show annual trends.
  • Highlight results for new sites.
  • Discuss trends taking in to account of number of years of available data.
  • Project forward results using LAQM.TG (22) guidance.

3.16 New Local Developments:

  • Identify and list new developments that may affect air quality.

3.17 Sources Outside of Local Authority Control:

  • Identify sources that may affect air quality but be outside of the local authorities' control such as SEPA-regulated activities and trunk roads.
  • Where data/information may be required from other organisations such as that relating to PPC installations from SEPA or trunk roads from Transport Scotland local authorities should approach these organisations early in the process of drafting the APR. Previously, submission of APRs has been delayed by obtaining this information at a late stage in the process and this should be avoided in future.

3.18 Action Plans:

  • List measures in action plan(s).
  • Expected or actual completion dates for action plan measures.
  • Measure status (planned, in progress, completed, delayed).
  • Funding status.
  • Key milestones for implementing action plan measures.
  • Update on progress implementing measures.
  • Barriers to implementation for delayed measures.

3.19 Measures to address air quality:

  • Summarise measures in the strategies that have a direct bearing on air quality (Air Quality Strategies, Local Transport Plans, Planning Policy documents – (i.e. Supplementary Planning Guidance), Noise Action Plans and Climate Change Strategies).
  • Report on progress with implementing these measure.

3.20 Planning and Policies:

  • Log planning applications for new developments for which an air quality assessment is being provided.

Progress on implementation of action plans

3.21 Although local authorities can submit separate action plan progress reports, they must report on progress delivering action plan measures annually in the APR. Section 2 of the APR template allows the local authority to report on progress against milestones for action plan measures and their current status. More information on action plans can be found in section 6.

Reporting against actions contained within CAFS2

3.22 Local authorities are required to report on progress against any CAFS2 actions relevant to their local authority. In particular there are two specific actions which must be reported on:

Placemaking – Plans and Policies

  • Local authorities with support from the Scottish Government will assess how effectively air quality is embedded in plans, policies, City Deals and other initiatives, and more generally in cross departmental working, identifying and addressing evidence, skills, awareness and operational gaps.

Transport – Low Emission Zones (LEZs)

  • Local authorities working with Transport Scotland and SEPA will look at opportunities to promote zero-carbon city centres within the existing LEZs structure. This reporting requirement will only apply to those local authorities with LEZs and will link to the action planning process being undertaken to implement LEZs.

Guidance on the types of information to be reported for CAFS2 actions is contained within the APR template.


Email: Andrew.Taylor2@gov.scot

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