In (2000) South Hams District Council produced a report which examined air quality across the District. The following text is a summary of that report it is taken from a leaflet which is also available in hard copy from the Council. The original, full report may be studied at Follaton House, Totnes, or a copy may be purchased; please contact the officers listed at the end of the summary. An electronic version of the full report will soon be available on the Internet.
AIR QUALITY REVIEW AND ASSESSMENT FOR THE SOUTH HAMS
A SUMMARY REPORT.
The Air Quality Review and Assessment Process A general overview
In order to implement the National Air Quality Strategy and associated Air Quality Regulations, Local Authorities must periodically review and assess the air quality in their areas against nationally prescribed, health-based, air quality objectives. These objectives specify the maximum pollutant concentrations in air at set dates in the future.
The review and assessment process is to be approached in up to three stages. If the first stage shows that one or more locations within a Local Authority area may have potential air pollution problems, then a second and possibly a third stage must be undertaken in order to examine the relevant pollution issues in more detail.
If, following a third stage Review and Assessment, a Local Authority concludes that air quality objectives are likely to be breached, then it must declare an Air Quality Management Area and formulate policies to improve air quality as necessary
Role of this summary
This summary has been written to mark the production of a joint report which details both the second and third stages of the Council’s Air Quality Review and Assessment. This follows on from a report of the Council’s Stage 1 Air Quality Review and Assessment which was produced and circulated in 1999.
This summary is designed to provide an outline of the findings which are detailed in the two full reports. (See the end of this leaflet for details of how to obtain copies of the reports.)
Summary of the Stage 1 Review and Assessment.
The Stage 1 Review and Assessment process involved the use of simple screening tools specified by the Government. These screening tools were designed to eliminate those pollutants and locations for which there was no need for any further assessment. Benzene and 1,3 Butadiene are pollutants that were screened out by these first stage methods. Pollutants that were not screened out at this Stage and therefore required assessment at Stage 2 were as follows:
* Carbon Monoxide (CO) at locations close to the A38 Devon Expressway as it runs through the South Hams District.
* Lead (Pb) at locations close to one ‘Part B process’ (ie. an industrial process which is authorised by the District Council under the Environmental Protection Act, Part 1, 1990).
* Nitrogen Dioxide (NO2) at locations close to the A38 Devon Expressway and the A380 (the Torbay ring road) as they run through the South Hams District; and at locations close to the A385 as it runs between Dartington and the east of Totnes. In addition, a need to examine potential NO2 emissions from the proposed power station at Langage near Plymouth was identified.
* Particulate Matter (PM10) at locations close to the A38 and the A380 as they run through the District; at locations close to specified industrial processes (ie. part ‘B’ processes see above) associated with china clay quarrying and processing operations and at sites potentially affected by fugitive dust emissions.
* Sulphur Dioxide (SO2) a need to examine potential SO2 emissions from the proposed power station at Langage near Plymouth was identified.
Summary of Stage 2 Review and Assessment.
The Review and Assessment at Stage 2 was undertaken during the first part of the year 2000. Various screening criteria approved by the Government were used; for example, pollutant concentrations arising from roads were assessed using the Design Manual for Roads and Bridges (DMRB) model. This is a simple, spread-sheet-based model which calculates likely pollution levels that arise for a given number and type of vehicle flow. Pollutant concentrations arising from industrial processes were assessed via the collection of process-specific data from the operators, and the application of this to screening tools provided by the Government in its published guidance to Local Authorities.
Results from the diffusion tube monitoring programme were used to help assess current Nitrogen Dioxide levels.
It was decided to make the assessments for NO2 and SO2 pollution concentrations likely to arise as a result of the proposed Langage power station at Stage 3 because the more advanced modelling techniques that were involved were more appropriately dealt with at that stage.
The Stage 2 Review and Assessment concluded that no further investigation was required for the following;
* Carbon Monoxide pollution arising from the A38.
* Nitrogen Dioxide pollution arising from the A380 and the A385.
* Lead pollution arising from the industrial process identified at Stage 1.
* Particulate Matter (PM10) pollution arising from the A38, the A380 and the A385, or that arising as a result of fugitive emissions from quarries, etc. along with most of the industrial processes examined (though emissions from one of these industrial processes did go through for examination at Stage 3).
Summary of Stage 3 Review and Assessment
The Stage 3 Review and Assessment mainly involved the use of advanced computer modelling techniques. At this stage, the only traffic-related pollution which had to be examined was Nitrogen Dioxide from vehicles on the A38. To do this, the AAQUIRE Regional Air Quality Model was used; this requires a considerable amount of additional information relating to vehicle types, road and adjacent land characteristics etc. and meteorological data to be input to the model. The model results were validated by reference to the results from the NO2 diffusion tube survey for the A38.
PM10 emissions from one of the industrial processes identified at Stage 2 were also assessed at Stage 3 using the AAQUIRE model.
Information on both SO2 and NO2 pollution concentrations that could potentially arise from the proposed Langage power station was taken from reports of the sophisticated modelling techniques (using ISC-3 and AERMOD respectively) employed by the Developer’s consultants (and which are verified by the Environment Agency).
The Stage 3 Review and Assessment concluded that no further investigation was required for any of the pollutants investigated.
The Overall Conclusions to the Review and Assessment Process
The Review and Assessment showed that Government objectives for all pollutants should not be breached and therefore there is no need to progress beyond Stage 3 by declaring any Air Quality Management Areas.
Review and Assessment of air quality is not a one-off exercise however and the Council will complete a further full review by the end of 2003. Moreover, in advance of this, the Council does intend to produce an Air Quality Strategy for the South Hams District. This is not a statutory requirement, but it is good practice. The Air Quality Strategy will include a renewed focus on some of the issues that have been addressed in this Review and Assessment, in particular with regard to emissions from traffic on the A38, the effects of the proposed power station at Langage (if it goes ahead) and minerals processing and quarrying operations within the District. The latter is also the subject of a current Review of Mineral Permissions (ROMPs) being undertaken by Devon County Council. The Strategy will also identify the positive measures that the Council can take and promote to maintain good air quality.
Consultation
The Council would like to involve the public and other agencies in our Air Quality Review and Assessment process. If you would like to make any comments, or if you require further information or a copy of one or both of the reports, please contact: 01803 861234
