USA Checklist 2009

Annual Status Report


The appraisal of the Annual Status Report forms part of the Review & Assessment process required under the Environment Act 1995 and subsequent Regulations.


Maidstone Borough Council currently has one AQMA declared for the exceedance of the nitrogen dioxide (NO2) annual mean objective as detailed below. This AQMA has been recently declared in 2018, and replaces the previous AQMA. The new, smaller AQMA boundary is based on the results of modelling. The main source of emissions in the AQMA continues to be road traffic from the main transport routes through the area which are the M2, M20, A20, A229, A249 A26 and A274.




Pollutants and Air Quality Objectives

One Line Description

Is air quality influenced by roads controlled by Highways England?

Level of Exceedance

At Declaration


Maidstone Town AQMA




The AQMA follows the carriageways of the main roads passing through the Borough, including the M20, A229, A20,A26, A249, and A274


Direct Comparison not possible

Direct Comparison not possible


In 2017 NO2 was monitored at 1 automatic rural background site and 60 diffusion tube sites. The roadside Maidstone A229 Kerbside automatic site was discontinued in 2016 due to changes in the road layout. There were nine exceedances of the annual mean NO2 objective in 2017 – seven within the AQMA, and two outside the AQMA (sites Maid 112 and Maid 113). Two diffusion tube sites (Maid 81 and 96, on Upper Stone Street) continue to demonstrate concentrations greater than 60µg/m3, which indicates potential exceedance of the 1-hour NO2 objective. PM10 was also monitored at the automatic background site, and no exceedances were demonstrated of the 24-hour or annual mean objectives.


A new AQAP for the amended AQMA has been published in 2017. Some progress has already been made towards the new AQAP measures. For example: planning progress towards retrofitting euro 3 buses to euro 5, exploring options for an anti-idling campaign, drafting a potential school programme for reducing impact of school traffic, and adopting the Kent and Medway Air Quality Planning Guidance.

On the basis of the evidence provided by the local authority the conclusions reached are acceptable for all sources and pollutants, under the provisos detailed in the commentary below. 


The next step for Maidstone Borough Council is to submit an Annual Status Report in 2019.



The report is well structured, detailed and provides the most of the information specified in the Guidance. The following commentary is provided to inform future reports:


1.    The NO2 monitoring results demonstrate continued exceedance within the AQMA, at seven diffusion tube sites, and two additional exceedances outside the AQMA, at sites Maid 112 and 113. These sites are both new in 2017, and the exceedances are relatively minor. The Local Authority should keep these sites under review for the next three years. If after this time the exceedances persist, consideration should be made in regards to progressing to detailed assessment and potential declaration of an AQMA.


2.    There is no evidence of exceedance of the annual or 24-hour PM10 objectives at present.


3.    The roadside automatic monitoring site in the AQMA was decommissioned in 2016. The Local Authority are recommending a new automatic monitoring station to be commissioned in Upper Stone Street, within the AQMA boundary, to determine if  there are hourly NO2 or annual PM10 exceedances in this area.


4.    This is highly supported, particularly considering the very high NO2 concentrations measured by diffusion tubes Maid 81 and 96 in Upper Stone Street, indicating exceedance of the hourly NO2 objective.


5.    It is encouraging to see active management of the air quality monitoring programme, with diffusion tube sites being discontinued and new sites being introduced in the last year. The Local Authority should continue to keep the network under review, and provide explanation in reports for changes which have been implemented.


6.    A new AQAP has been published for the Maidstone AQMA in 2017. AQAP measures have been presented in a table in Appendix F, however this table is difficult to read and the Local Authority has not followed the AQAP reporting template.


7.    The Local Authority must report AQAP measures and progress against them in Table 2.2 (Section 2.2) – “Progress on Measures to Improve Air Quality”. The Technical Guidance TG (16) states that section 2.2 should be the core section of the ASR, with Table 2.2 providing the key information. It is therefore of high importance that this is correctly completed in future reporting.


8.    AQAP measures presented in Appendix F do not appear to target improvements at specific pollution hotspots. The Local Authority should consider developing additional AQAP actions which are specific to air quality improvement in pollution hotspots, such as Upper Stone Street.


9.    Annualisation has been carried out for 20 diffusion tubes, as outlined in Table C.2 in Appendix C. It would be useful if the Local Authority also provided information on how the annualisation factors for each site were calculated, i.e. example calculations and details of which background sites have been used in the annualisation.


10.  In future reports, the AQMA boundary and the monitoring locations should be demonstrated on the same maps. It is very difficult to tell which monitoring sites are within the AQAP based on the maps presented in Appendix D. It is also unnecessary to include maps of sites which are no longer in use in this section.


11.  Table B.1 needs to be revised to reflect the latest version of the Defra template for this document. The table should include distance correction information.  This should be continued in all future ASR reports.






This commentary is not designed to deal with every aspect of the report.  It highlights a number of issues that should help the local authority either in completing the Annual Status Report adequately (if required) or in carrying out future Review & Assessment work.


Issues specifically related to this appraisal can be followed up by returning the attached comment form to Defra, Welsh Assembly Government, Scottish Government or DOE, as appropriate.


For any other queries please contact the Local Air Quality Management Helpdesk:

Telephone:           0800 0327 953



Appraisal Response Comment Form


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