Local air quality management: policy guidance

Guidance to help local authorities with their local air quality management (LAQM) duties under Part IV of the Environment Act 1995.

3. Review and Assessment

Annual Progress Report (APR) templates are available on the Defra LAQM Portal. Examples of completed reports are available on the Review and Assessment helpdesk web site at: http://laqm.defra.gov.uk/review-and-assessment/good-practice/examples.html and also on the Air Quality in Scotland website[8].

3.1 New monitoring data

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 exceedances of the 1-hour objective value of 200 microgrammes/m3.

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. Particular matters to take account of when preparing and assessing monitoring results are set out in Box 3.1, below. Local authorities should also contact SEPA to discuss suitability of monitoring locations.

3.2 Other information to include in the annual progress report

When reporting the monitoring data the following should be included where possible:

  • A map showing the monitoring locations.
  • Plots showing trends in concentrations e.g. plots of annual mean nitrogen dioxide concentrations for the last five years

Box 3.1: Matters to take into account when reporting monitoring data

1 - 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.

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

4 - 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. Details of any colocation studies should also be provided within the report within the QA/QC section.

5 - Summary information should be provided on QA/QC.

6 - 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?

7 - 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.”

8 - 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).

9 - 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.

The APR should also draw attention to:

  • Results for new monitoring sites and whether they reveal any new information about local air quality.
  • Evidence of any trends over recent years (including observations from during the COVID-19 pandemic). 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.

Where data/information may be required from other organisations such as relating to regulated sites 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.

3.3 Progress on implementation of action plans

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 of this guidance.

3.4 Assessment of monitoring data

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 exceedances that may not have been previously identified and also help to gauge progress on when the objectives are likely to be complied with.

Box 3.2: - Information to be included in the APR

New Monitoring data - 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 monitoring sites.

Discuss trends.

Take account of number of years of available data.

Project forward results using LAQM.TG (22) guidance.

New Local Developments - Identify and list new local developments that may affect air quality.

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.

Action Plans - List measures in action plan and implementation timescales (including dates for completion).

Provide update on progress implementing measures.

Provide details of funding for measures.

Projected date for revocation of AQMA.

Local Air Quality Strategy - Summarise Strategy or progress on preparing a Strategy or reviews of the Strategy.

Describe consultation/publicity for Strategy.

Report on progress on implementing measures within strategy.

Planning and Other Policies - Log planning applications for new developments for which air quality assessment is being provided.

List local policies and strategies that relate to air quality and any changes that may have been introduced.

Regional Transport Strategies and Local Transport Plans - Summarise measures in the Strategies that have a direct bearing on air quality.

Report on progress with implementing these measures.

3.5 Reporting against actions contained within CAFS2

Local authorities are expected to report on progress against any CAF2 actions relevant to their local authority. In particular there are two specific actions which should 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. This links to the information set out in Box 3.2.

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.

3.6 LEZ reporting requirements

Section 29 of the Transport (Scotland) Act 2019 requires a local authority operating an LEZ scheme, as soon as reasonably practicable after the end of the financial year, to:

  • Prepare an annual report on the operation and effectiveness of the scheme.
  • Publish the report in such manner as it considers appropriate.
  • Send a copy of the report to the Scottish Ministers.
  • Lay a copy of the report in the Scottish Parliament.

Air pollution level reduction trends must be considered when evaluating the effectiveness of an LEZ scheme. Transport Scotland’s LEZ guidance document[9] states that the performance of the LEZ in reducing levels of air pollution will be available within the Annual Progress Report (APR) local authorities are required to produce through the Local Air Quality Management (LAQM) process.


Email: andrew.taylor2@gov.scot

Back to top