Air quality progress report (2005)

Air quality progress report for the Borough of Woking

Environmental Health Service 2005

Executive summary

This is the Air Quality Progress Report 2005 for the Woking Borough Council (“the Council”). This report fulfils this part of the Council’s commitment to the continuing Local Air Quality Management (LAQM) process.

Following the requirements of the guidance LAQM. PRG (03) produced by the Department of Environment, Food and Rural Affairs (DEFRA), the report includes updated monitoring results and details of relevant new local developments. Progress reports are required when the Council is not carrying out either an Updating and Screening Assessment or Detailed Assessment of air quality.

The Council’s earlier Review and Assessments of air quality confirmed that there were no locations with relevant public exposure where the government’s air quality objectives might be exceeded.

The more up to date monitoring of nitrogen dioxide and benzene in this report confirms that the Government’s air quality objectives are not being exceeded at those locations with relevant public exposure.

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1 Introduction to air quality progress report

1.1 Overview

This is the Air Quality Progress Report 2005 for the Woking Borough Council. This report is intended to fulfil the Council’s continuing commitment towards the Local Air Quality Management (LAQM) process.

1.2 Background

The LAQM process forms a key part of the Government’s Air Quality Strategy to achieve the air quality objectives prescribed in the Air Quality (England) Regulations 2000 and 2002. Air quality progress reports were introduced following a detailed evaluation of the first round of local authority Review and Assessment. This evaluation identified a need both to develop a longer-term vision for both LAQM and encourage the integration of air quality into the routine work of local authorities.

Local Authorities are required by section 88 (2) of the Environment Act 1995 to have regard to the government’s guidance documents when carrying out their LAQM duties. To assist local authorities and provide guidance for the overall LAQM process, the Department for Environment, Food and Rural Affairs (DEFRA) issued the following policy and technical guidance documents: LAQM PG (03), LAQM PG (S) (03), and LAQM TG (03).

LAQM PRG (03) supplemented this guidance to assist in the production of air quality progress reports. Based on this guidance local authorities are required to produce Progress Reports in those years when they are not carrying out an Updating and Screening Assessment (USA) or a Detailed Assessment of air quality.

As part of its earlier duties the Council completed its USA of the seven LAQM pollutants in 2003. The conclusion of that work was that the Council needed to undertake a Detailed Assessment for nitrogen dioxide for parts of its area only; Parvis Road in West Byfleet and Maybury Road in Woking.

The aim of the Council’s Detailed Assessment was to determine with reasonable certainty whether or not there is a likelihood of the AQ objectives being achieved. The assumptions in the Detailed Assessment were therefore in depth and the data used were quality assured to a high standard. This allowed the Council to have confidence in reaching a decision whether to declare an Air Quality Management Area or not. When carrying out its Detailed Assessment the Council applied its best estimates to all components used to produce the estimated future concentrations.

The modelling predictions for the Parvis Road area of Woking indicated that annual mean NO2 concentrations did not exceed the air quality objective where there is relevant exposure. The junction of Maybury Road and Monument Road were also re-assessed in the light of these findings and found not to exceed the annual mean objective. On the basis of these findings the Council was not required to declare an Air Quality Management Areas (AQMA).

The guidance advises that the Progress Report is not designed to represent a further USA, although it states that, if at any time a risk is identified that an air quality objective might be exceeded, a Detailed Assessment should be carried out without delay.

The overall aim of the Progress report is to report on progress on implementing LAQM and report progress in achieving, or maintaining concentrations below the air quality objectives. The guidance considers that these aims can be best achieved by reporting on new results and new developments that might affect local air quality.

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2 New monitoring results in the Borough of Woking

2.1 Outline of monitoring undertaken

The Council carried out further monitoring of nitrogen dioxide (NO2) and benzene during 2003/4. It has not undertaken monitoring of other LAQM air pollutants during this period.

The Government has adopted two air quality objectives for each of these pollutants as shown in Table 1 below.

Table 1 Air quality strategy objectives for NO2 and benzene

Pollutant	Objective concentration	Objective measured as	Date to be achieved by
Nitrogen Dioxide (provisional)	200 mgm-3 not to be exceeded more than 18 times a year. 40 mgm-3	1 hour mean Annual mean	31 Dec 2005 31 Dec 2005
Benzene	16.25  mgm-3 5 mgm-3	Running annual mean  Annual mean	31 Dec 2003  31 Dec 2010

2.2 NO2 Passive Diffusion Tube Monitoring

The Council has carried out monitoring of NO2 using passive diffusion tubes out since 1996. Over the years more monitoring sites have been chosen to gain a better understanding of air quality. In 2004 the monitoring was undertaken at 14 locations.

All of the Council’s NO2 diffusion tubes are supplied and analysed by Lambeth Scientific Services and the method of preparation is 50% TEA in acetone. Monitoring using diffusion tubes is inherently less precise and accurate than continuous monitoring using automatic analysers. To reduce potential errors the guidance requires that the monitoring result be bias adjusted using results from colocation studies of diffusion tubes and continuous analysers.

The results given in the Table 2 are for the 6 most recent years (i.e. from 1999 to 2004) and include sites located in background areas and at roadside and kerbside locations. Most of the sites represent locations relevant for public exposure. The most notable exception to this is the Parvis Road (M25 bridge) diffusion tube, which is located in the middle of a bridge over the M25 (this site has been italicised in Table 2 below). The other Parvis Road also does not represent relevant exposure (this discussed in the Council’s 2004 Detailed Assessment of air quality).

The Council does not operate a continuous analyser and therefore a co-location study has not been undertaken to determine a specific local bias adjustment factor to determine whether the diffusion tubes are under or over reading. Default bias adjustment factors have therefore been applied in this instance (as derived by from the R & A website). This indicates that the tubes underestimate concentrations by approximately 5% for 2003 and 8% for 2004. The results for 1999 to 2002 all assumed that the tubes underestimate by 6% (see Woking B.C Updating and Screening Assessment, 2003).

Table 2 Annual mean NO2 concentrations for the Borough of Woking (1999 – 2004) (μgm-3)

 

Location	Type	1999	2000	2001	2002	2003	2004
Cotteridge 1, Constitution Hill, Woking	k	34.4	30.4	38.5	48.1	39.9	35.0
Cotteridge 2, Guildford Rd, Woking	k	54.7	44.5	34.4	30.2	25.7	31.6
Parvis Rd, bridge over M25	other	72.9	50.6	40.5	58.3	48.0	53.3
Church Rd Byfleet	b	40.5	32.4	26.3	30.4	28.1	25.3
Roseberry Crescent, Old Woking	k	24.3	22.3	22.3	20.6	21.1	17.6
Anchor Hill, Knaphill	k	52.6	36.4	42.5	37.8	39.4	38.8
Lincoln Drive, Pyrford	k	32.4	28.3	22.3	22.6	24.6	28.4
Victoria Way, Woking	k	56.7	40.5	46.6	43.4	42.6	30.9
Bittern Drive, Goldsworth Park	b	28.3	22.3	24.3	18.9	18.2	20.4
Bagshot Rd, Brookwood	k	40.5	36.4	30.4	29.2	32.6	25.7
Parvis Rd, Byfleet	r	60.7	54.7	56.7	55.0	47.5	48.5
Woodham Lane, Woking	k	48.6	36.4	38.5	33.7	31.4	37.7
Goldsworth Rd, Woking	k	n.o	32.4	32.4	37.5	35.9	30.3
Monument Rd, Old Woking	k	n.o	38.5	42.5	37.5	35.8	32.8

(n.o indicates not in operation, italics indicate site does not have relevant exposure) (k: indicates kerbside, b: background, r: roadside)

The monitoring results for the two background sites (Church Road, Byfleet and Bittern Drive, Goldsworth Park) have since 2000 been consistently below the annual mean objective.

The results for the kerbside sites at Goldsworth Road, Woking; Roseberry Crescent, Old Woking; Lincoln Drive, Pyrford; Woodham Lane, Woking and Bagshot Road, Brookwood have also been consistently below the annual mean objective for the years 2000 to 2004.

The Parvis Road (Byfleet and M25) sites are the only locations monitored where the annual mean results have been consistently greater than the 40 mgm-3 standard for all the years 1999 to 2004. Both sites have previously been discussed in the both Council’s Updating and Screening Assessment in 2003 and Detailed Assessment in 2004. As mentioned above the M25 site does not represent a location relevant for public exposure.

The Parvis Road (Byfleet) site was however investigated more fully in the Council’s Detailed Assessment and based on the in depth modelling carried out found not to exceed the air quality objective. As a result of this finding the following comment was made (see Detailed Assessment for Woking B.C 2004):

“The measured concentrations also indicated that the site is heavily polluted, indeed more so than other far more heavily trafficked sites e.g. the A3 (greater than 100,000 vehicles per day). This is despite the site having only a moderate traffic flow (22,000) as outlined in Appendix D with low numbers of HGVs. The road is also open to one side and therefore cannot be considered a street canyon. A possible reason for the high concentrations measured is that the diffusion tube is sited very close to the kerb (as a result this means that it does not represent exposure at the façade).”

In conclusion it was confirmed that there was no relevant exposure at this monitoring site and hence there was no need for the Council to designate an AQMA. This report was accepted by DEFRA in its consultation response to the Council.

The only other site where the objective has been exceeded is Victoria Way in Woking in 2003. Monitoring at the same location in 2004 however indicated that the objective was easily met with a bias adjusted annual mean of approximately 30 μgm-3.

The results are also presented in Figure 1. This shows for some sites that concentrations are decreasing with time, although as to be expected there remains some inter annual variability, which will relate to both meteorological conditions as well as the release of atmospheric emissions.

Figure 1 Annual mean NO2 concentrations for the Borough of Woking

2.2 Benzene Diffusion Tube Monitoring

The Council also undertakes benzene monitoring by diffusion tube at one representative location in its area. The results are shown in Table 3 and this monitoring indicates that annual mean levels are well below the 2003 objective. Concentrations have varied in recent years but remain less than 3 μgm-3 at the site. As no continuous monitoring of benzene is undertaken nearby there has been no site co-location and no derivation of bias correction.

Table 3 Results of benzene monitoring (μgm-3) in Woking (1999-2004)

The results confirm that the current running annual mean concentrations are much lower than the 2003 objective of 16.25 μgm-3 and the 2010 objective of 5 μgm-3.

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3 New local developments

This section outlines those local developments that have taken place that may affect air quality. These are not for consideration now but are listed for a more thorough assessment for the next round of Review and Assessment. The guidance identifies the following developments that should be considered:

• New industrial processes included in the list of Appendix 2 LAQM. TG 03.
• New developments with an impact on air quality, especially those that will significantly change traffic flows. Only include those developments with planning permission granted.
• New landfill sites, quarries, etc with planning permission granted and nearby relevant exposure.

Table 4 New Local Developments since 2003

During 2004 the Council gave planning permission to the Surrey County Council for a new County Hall to be built in Woking town centre on Victoria Way. An Environmental Statement was produced for the development and this examined the potential impact on air quality of the development. The findings were based on 2006 as the proposed opening year. These indicated that the development would not have a significant impact on local air quality. The modeling undertakenindicated that the highest concentrations in the area did not exceed the current NO2 and PM10 objectives. The development was estimated to increase concentrations very slightly, but this was not considered significant and did not exceed the objectives.

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4 Other relevant initiatives

As the Council has not designated an AQMA it is not required to produce an Air Quality Action Plan. The Council however has maintained a commitment to improving air quality through its other initiatives, most notably through its Woking LA21 programme and the Woking Climate Change Strategy. As a result of these initiatives the Woking Borough Council, from an environmental perspective, is widely recognised as being the most energy efficient local authority in the country (see http://www.woking.gov.uk/environment).

The Council in 2004 also produced its Local Development Scheme as part of its requirement to produce a Local Development Framework by 2007. This scheme incorporates the promotion of sustainable development, including improving air quality (see http://www.woking.gov.uk/council/planning/ldf/sustappraisal).

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5 Conclusion

This Air Quality Progress Report for 2005 fulfils the requirements of the DEFRA PRG 03 guidance as has updated monitoring results in the Borough and noted new relevant local developments and other initiatives.

The up to date monitoring results continue to indicate that the Government’s current air quality objectives are being met at locations where there is relevant public exposure. Based on the findings in this report there is no need to progress to a Detailed Assessment.

The Council will continue its air quality monitoring programme and prepare for its next round of Review and Assessment in 2006.