However further assessment of NO2 was required at Stage 3 for the A4 in central Newbury and Thatcham, the A339 in central Newbury and the M4, within the West Berkshire District.
An assessment of potential NO2 concentrations at properties 2005, was undertaken using detailed modelling software.
at these locations in 2000 and The report concluded that at
residential facades and locations of relevant exposure was unlikely that the AQOs would be exceeded and an
adjacent to the A4, A339 AQMA was not declared.
Phase 2 of Review and Assessment
A second phase of Review and Assessment is required under the ‘on-going’ Review and Assessment process, which is designed to build on the technical approach developed for the first round assessments, and identify the on-going needs or requirements for an AQMA designation. Whilst authorities must carry out what is termed the Updating and Screening Assessment (U&SA), it is not the intention that all will need to progress to a Detailed Assessment.
Updating & Screening Assessment (U&SA)
Since the publication of reports for the first round of Review and Assessment, there are potentially a number of issues that need to be addressed in terms of changes to the sources and emissions of pollutants that may affect ambient air quality in LA areas. Furthermore, new policy developments and revisions to published guidance require consideration within the on- going assessment of air quality.
The U&SA is based on a checklist whereby sources identified in the first round of Review and Assessment and any new or altered emission sources, are reviewed with regard to their current significance and any requirement for further assessment.
Detailed Assessment and Progress Reports
Where the U&SA identifies a potential for the AQOs to be exceeded at locations of relevant public exposure, the LA will be required to undertake a Detailed Assessment.
The Detailed Assessment develops further the information gathered and the conclusions reached from the U&SA and involves the use of more sophisticated modelling and monitoring techniques. The Detailed Assessment will be used to determine whether the likelihood exists for the AQOs to be exceeded and the consequent need to declare or revise an AQMA.
Where it is concluded that a Detailed Assessment is not necessary, a Progress Report is required to be produced on an annual basis (in years when a Detailed Assessment is not required) as detailed in Figure 2.1 below.
h:\projects\em-260\10000 projects\10151 aq w.berks r&a - phase 2\d design\reporting\10151 aq final u&sa.doc10151-01