air quality progress report 2013 - stevenage2013 air quality progress report for stevenage borough...

2013 Air Quality Progress Report for Stevenage Borough Council In fulfillment of Part IV of the Environment Act 1995 Local Air Quality Management August 2013

Stevenage Borough Council

LAQM Progress Report 2013 1

Local Authority Officer

Wesley A Cushing Environmental Health Officer

Department Environmental Health and Licensing

Address Daneshill House, Danestrete, Stevenage, Hertfordshire SG1 1HN

Telephone 01438 242905 e-mail [email protected] Report Reference

number SBC/PR/2013

Date September 2013



Executive Summary

Part IV of the Environment Act 1995 requires Local Authorities to periodically review and assess local air quality against the air quality objectives contained in the Air Quality Regulations. An Updating and Screening Assessment (USA) was undertaken in 2012. This assessment evaluated the Local Authority’s area and established any areas likely to exceed the air quality objectives. Where Detailed Assessments are not required as a result of the Updating and Screening Assessment, Annual Progress Reports are required to update on changes within the district. Monitoring of nitrogen dioxide and PM10 was undertaken at the continuous monitoring site on Lytton Way. In addition, 22 nitrogen dioxide diffusion tubes sites were placed at sites around the borough. This monitoring did not identify any exceedences of the Air Quality Objectives where there was relevant exposure. One diffusion tube on Hitchin road measured levels slightly exceeding the Air Quality Objective, however this was not representative of relevant exposure. Relevant exposure was measured on the façade of three properties along this road and all three measured annual mean concentrations below the Objective. It is considered that there is currently no need to undertake a detailed assessment as the results obtained from 2012 monitoring data do not suggest that there are any relevant exceedences of the Air Quality Objectives in Stevenage Borough.



Table of Contents

1 Introduction 5

1.1 Description of Local Authority Area 5

1.2 Purpose of Progress Report 5

1.3 Air Quality Objectives 6

1.4 Summary of Previous Review and Assessments 8

2 New Monitoring Data 10

2.1 Summary of Monitoring Undertaken 10

2.2 Comparison of Monitoring Results with Air Quality Objectives 15

3 New Local Developments 23

4 Local / Regional Air Quality Strategy 24

5 Planning Applications 25

6 Air Quality Planning Policies 26

7 Local Transport Plans and Strategies 27

8 Climate Change Strategies 28

9 Implementation of Action Plans 29

10 Conclusions and Proposed Actions 30

10.1 Conclusions from New Monitoring Data 30

11 References 31



List of Tables

Table 1.1 Air Quality Objectives included in Regulations for the purpose of LAQM in England

Table 2.1 Details of Automatic Monitoring Sites

Table 2.3 Results of Automatic Monitoring for NO2: Comparison with Annual Mean Objective

Table 2.4 Results of Automatic Monitoring for NO2: Comparison with 1-hour Mean Objective

Table 2.5 Results of NO2 Diffusion Tubes 2012

Table 2.6 Results of NO2 Diffusion Tubes (2008 to 2012)

Table 2.7 Results of Automatic Monitoring for PM10: Comparison with Annual Mean Objective

Table 2.8 Results of Automatic Monitoring for PM10: Comparison with 24-hour Mean Objective

List of Figures

Figure 2.1 Map of Automatic Monitoring Sites

Figure 2.2 Map of Non-Automatic Monitoring Sites

Appendices

Appendix 1 Quality Assurance / Quality Control (QA/QC) Data

Appendix 2 Monthly diffusion tube results



1 Introduction

1.1 Description of Local Authority Area

Stevenage is located in Central Hertfordshire. It is a compact urban area covering

25,412 m2 with a population of approximately 80,000 people. Built in the 1950s, it

was Britain’s first new town, and was designed with segregated areas for

commercial, industrial and residential purposes. The main industrial area is located

on the western edge of the town, between the A1(M) and the main London to

Peterborough train line. This segregation of land uses has the effect of reducing

environmental impacts of industry due to the increased distance between the source

of pollution and the receptor. Road traffic is considered a main source of air pollution

in Stevenage as there are a number of busy roads, some of which have residential

properties nearby. Stevenage Borough Council has not declared any Air Quality

Management Areas in the borough to date.

1.2 Purpose of Progress Report

This report fulfils the requirements of the Local Air Quality Management process as

set out in Part IV of the Environment Act (1995), the Air Quality Strategy for England,

Scotland, Wales and Northern Ireland 2007 and the relevant Policy and Technical

Guidance documents. The LAQM process places an obligation on all local

authorities to regularly review and assess air quality in their areas, and to determine

whether or not the air quality objectives are likely to be achieved. Where

exceedences are considered likely, the local authority must then declare an Air

Quality Management Area (AQMA) and prepare an Air Quality Action Plan (AQAP)

setting out the measures it intends to put in place in pursuit of the objectives.

Progress Reports are required in the intervening years between the three-yearly

Updating and Screening Assessment reports. Their purpose is to maintain continuity

in the Local Air Quality Management process.



They are not intended to be as detailed as Updating and Screening Assessment

Reports, or to require as much effort. However, if the Progress Report identifies the

risk of exceedence of an Air Quality Objective, the Local Authority (LA) should

undertake a Detailed Assessment immediately, and not wait until the next round of

Review and Assessment.

1.3 Air Quality Objectives

The air quality objectives applicable to LAQM in England are set out in the Air

Quality (England) Regulations 2000 (SI 928), The Air Quality (England) (Amendment)

Regulations 2002 (SI 3043), and are shown in Table 1.1. This table shows the

objectives in units of microgrammes per cubic metre µg/m3 (milligrammes per cubic

metre, mg/m3 for carbon monoxide) with the number of exceedences in each year

that are permitted (where applicable).



Table 1.1 Air Quality Objectives included in Regulations for the purpose of LAQM in England

Pollutant Air Quality Objective Date to be

achieved by Concentration Measured as

Benzene 16.25 µg/m3 Running annual

mean 31.12.2003

5.00 µg/m3 Annual mean 31.12.2010

1,3-Butadiene 2.25 µg/m3 Running annual

mean 31.12.2003

Carbon monoxide 10 mg/m3 Running 8-hour

mean 31.12.2003

Lead 0.50 µg/m3 Annual mean 31.12.2004

0.25 µg/m3 Annual mean 31.12.2008

Nitrogen dioxide

200 µg/m3 not to be exceeded more than 18 times a

year

1-hour mean 31.12.2005

40 µg/m3 Annual mean 31.12.2005

Particulate Matter (PM10)

(gravimetric)

50 µg/m3, not to be exceeded more than 35 times a

year

24-hour mean 31.12.2004

40 µg/m3 Annual mean 31.12.2004

Sulphur dioxide

350 µg/m3, not to be exceeded more

than 24 times a year

1-hour mean 31.12.2004

125 µg/m3, not to be exceeded more than 3 times a year

24-hour mean 31.12.2004

266 µg/m3, not to be exceeded more

than 35 times a year

15-minute mean 31.12.2005



1.4 Summary of Previous Review and Assessments

Stevenage Borough Council undertook the first round of review and assessment in

2001. It was found that there was no requirement to proceed to the next stage.

An Updating Screening Assessment (USA) was undertaken in 2003 as the first

phase of the second round of review and assessment. This also indicated that there

were no air quality issues within the borough. The progress reports undertaken in

2004 and 2005 concluded that there was no need to proceed to the next stage of the

review and assessment process.

The USA that was undertaken as the first phase of the third round of review and

assessment in 2006 identified one area that required a detailed assessment in

respect of the annual mean for nitrogen dioxide. This area (the A602 Hitchin Road)

was identified through DMRB modelling and had not previously been monitored

through diffusion tubes. A nitrogen dioxide diffusion tube site was set up on Hitchin

Road roadside.

A Detailed Assessment of Hitchin Road was undertaken in 2007. It concluded that

the annual mean objective for nitrogen dioxide was not likely to be exceeded at the

nearest receptor and that the air quality objective was predicted to be met by 2010.

The results from the diffusion tube monitoring at this site were used in this

assessment.

The Progress report that was undertaken in 2008 indicated that there were slight

rises in levels of nitrogen dioxide at many of the monitoring sites with two sites,

Danestrete and Hitchin Road appearing to exceed the 40µg/m3 target. However it

was assessed that the public were unlikely to be exposed for long periods of time at

Danestrete, and modelling showed the levels of exposure affecting the residents at

Hitchin Road were below the objectives. The council commenced additional

monitoring adjacent to the residents of this road in order to confirm compliance.



The Progress Reports of 2010 and 2011 found no exceedences of the Air Quality

Objectives, although again the site at Hitchin Road recorded a figure close to the

objective. This was not representative of relevant exposure.

The USA of 2012 identified one exceedence of the Air Quality Objectives, at Hitchin

Road. This site is not considered representative of relevant exposure, and three

other sites on Hitchin Road provided annual mean concentrations below the

objective.



2 New Monitoring Data

2.1 Summary of Monitoring Undertaken

2.1.1 Automatic Monitoring Sites

The Automatic Monitoring Station is located on a roadside site at Lytton Way,

Stevenage. It monitors nitrogen dioxide using the chemiluminescent method, and

PM10 using a Tapered Element Oscillating Microbalance (TEOM).

Figure 2.1 Map of Automatic Monitoring Sites



Table 2.1 Details of Automatic Monitoring Sites

Site Name Site Type X OS

Grid Ref Y OS

Grid Ref Pollutants Monitored In AQMA?

Monitoring Technique

Relevant Exposure?

Distance to kerb of

nearest road

Does this location

represent worst-case exposure?

Stevenage 1 Roadside 523586 223967 NO2 N Chemiluminescent N (110m) 3m Y

Stevenage 1 Roadside 523586 223967 PM10 N TEOM N (110m) 3m Y



2.1.2 Non-Automatic Monitoring Sites

Diffusion tubes are used to monitor air quality at 22 sites across the borough.

Figure 2.2 Map of Non-Automatic Monitoring Sites



Table 2.2 Details of Non- Automatic Monitoring Sites

Site Number

Site Name Site Type

X OS Grid Ref

Y OS Grid Ref

Pollutants Monitored

In AQMA?

Is monitoring collocated

with a Continuous

Analyser (Y/N)

Relevant Exposure?

(Y/N with distance

(m) to relevant

exposure)

Distance to kerb of nearest road (m) (N/A if not applicable)

Does this location

represent worst-case

exposure?

1 Town Centre Kerbside 523771 224090 NO2 N N N (102 m) 2 Y

2 Ashdown

Road Background 525832 221495 NO2 N N

Y (14 m) 1.7

3 Monks View Background 524857 222756 NO2 N N Y (9.5 m) 2

4 Bedwell

Crescent Kerbside 524345 224468 NO2 N N

N (20 m) 1

5 Salisbury


Y (6.6 m) 17.5

6 Letchmore


Y (14 m) 1.4

7 High Street Kerbside 523278 225479 NO2 N N N (9 m) 2.3 Y

8 Fishers Green Background 522259 226001 NO2 N N

Y (18 m) 1

9 Magpie

Crescent Kerbside 526652 223438 NO2 N N

N (12.5 m) 1.9

10 Shoreham

Close Kerbside 522075 225568 NO2 N N Y (8 m) 2.1

11 Newlyn Close Kerbside 522126 224862 NO2 N N Y (3.5 m ) 1.7

12 Chadwell

Road Kerbside 522955 223335 NO2 N N

N (25 m) 0.3

13 Whitney

Drive Kerbside 523070 226070 NO2 N N

Y (8 m) 1.9



Site Number

Site Name Site Type

X OS Grid Ref

Y OS Grid Ref

Pollutants Monitored

In AQMA?

Is monitoring collocated

with a Continuous

Analyser (Y/N)

Relevant Exposure?

(Y/N with distance

(m) to relevant

exposure)

Distance to kerb of nearest road (m) (N/A if not applicable)

Does this location

represent worst-case

exposure?

14 Lytton Way 1 Kerbside 523586 223967 NO2 N Y N (110 m) 3 Y

15 Lytton Way 2 Kerbside 523586 223967 NO2 N Y N (110 m) 3 Y

16 Lytton Way 3 Kerbside 523586 223967 NO2 N Y N(110 m) 3 Y

17 Hitchin Road Kerbside 522700 226550 NO2 N N N (14 m) 2.4 Y

18 Fairlands

Valley Park Background 525425 224183 NO2 N N

N (167 m) 172.5

19 7 Tates Way Kerbside 522700 226570 NO2 N N Y (3 m) 9

20 3 Coreys Mill

Cottages Kerbside 522710 226550 NO2 N N

Y (1 m) 8

21 13 Hitchin

Road Kerbside 523128 225677 NO2 N N

Y (1 m) 16

22 Townsend

Mews Kerbside 523360 224786 NO2 N N

Y (1m) 7.8

Y



2.2 Comparison of Monitoring Results with Air Quality Objectives

Stevenage Borough Council monitors nitrogen dioxide and particulate matter.

Due to a fault with the air conditioning unit in June of 2012, the data gained for PM10

was reduced to 92.8% and for NOx, 93.8%.



Nitrogen Dioxide (NO2)

Automatic Monitoring Data

Table 2.3 Results of Automatic Monitoring for NO2: Comparison with Annual Mean Objective

Site ID Site Type Within

AQMA?

Valid Data Capture for Monitoring Period % a

Valid Data Capture 2012

% b

Annual Mean Concentration (µg/m3)

2008* c 2009* c 2010* c 2011* c 2012 c

SE1 Kerbside N n/a 93.8 29 30 31 29 28

Table 2.4 Results of Automatic Monitoring for NO2: Comparison with 1-hour Mean Objective


AQMA?


Valid Data Capture 2012

% b

Number of Hourly Means > 200µg/m3

2008* c 2009* c 2010* c 2011* c 2012 c

SE1 Kerbside N Y 93.8 0 0 0 0 0



Diffusion Tube Monitoring Data

Bias adjustment and annualisation calculations can be found at Appendix A During 2012, only one of the nitrogen dioxide diffusion tubes recorded an annual mean

greater than the objective of 40 g/m3. The tube at Hitchin Road recorded an annual

mean of 43 g/m3, however this tube does not reflect relevant exposure. The three tubes

that were erected in June 2008 to reflect relevant exposure (on the facades of residential properties along this road – tubes 19, 20 and 21) recorded annual means of 32, 26 and 33 g/m3 respectively.



Table 2.5 Results of NO2 Diffusion Tubes 2012

Site ID Location Site Type Within

AQMA?

Triplicate or Co-located

Tube

Full Calendar Year Data Capture 2012

(Number of Months or %) a

2012 Annual Mean Concentration (µg/m3) -

Bias Adjustment factor = 1.01 b

1 Danestrete Kerbside N Y 75 26.90

2 Ashdown Road Background N N 100 18.70

3 Monks View Background N N 100 22.55

4 Bedwell Crescent Kerbside N N 91.67 19.31

5 Salisbury Road Background N N 100 15.68

6 Letchmore Road Background N N 100 22.24

7 High Street Kerbside N N 91.67 24.62

8 Fishers Green Background N N 100 21.38

9 Magpie Crescent Kerbside N N 83.33 25.28

10 Shoreham Close Kerbside N N 100 30.18

11 Newlyn Close Kerbside N N 83.33 18.74

12 Chadwell Road Kerbside N N 100 19.63

13 Whitney Drive Kerbside N N 100 27.14

14 Lytton Way 1 Kerbside N Y 100 32.33

15 Lytton Way 2 Kerbside N Y 83.33 26.45

16 Lytton Way 3 Kerbside N Y 100 32.94

17 Hitchin Road Kerbside N N 100 43.32

18 Fairlands Valley Park Background N N 100 16.96

19 7 Tates Way Kerbside N N 100 39.69

20 3 Coreys Mill Lane Kerbside N N 100 35.86

21 13 Hitchin Road Kerbside N N 100 25.99

22 Townsend Mews Kerbside N N 100 25.16

In bold, exceedence of the NO2 annual mean AQS objective of 40µg/m3.



Table 2.6 Results of NO2 Diffusion Tubes (2008 to 2012)

Site ID Site Name Site Type Within

AQMA?

Annual Mean Concentration (µg/m3) - Adjusted for Bias a

2008 (Bias = 0.93)

2009 (Bias = 0.93)

2010 (Bias = 0.93)

2011 (Bias = 0.93)

2012 (Bias Adjustment

Factor = 1.01)

1 Town Centre Kerbside N 33.53 29.56 32.1 33.93 26.90 2 Ashdown Road Background N 18.47 16.53 16.1 18.05 18.70 3 Monks View Background N 23.29 20.38 18.9 23.02 22.55

4 Bedwell Crescent Kerbside N 22.37 19.07 19.3 20.69 19.31

5 Salisbury Road Background N 19.10* 14.70 13.4 15.67 15.68

6 Letchmore Road Background N 25.62* 18.08 16.8 17.53 22.24 7 High Street Kerbside N 31.84* 26.93 28.8 30.53 24.62 8 Fishers Green Background N 22.60 18.33 19.6 21.24 21.38

9 Magpie Crescent Kerbside N 25.49 24.16 23.7 24.05 25.28

10 Shoreham Close Kerbside N 31.06 25.07 26.0 28.25 30.18 11 Newlyn Close Kerbside N 23.21 20.08 19.8 21.28 18.74 12 Chadwell Road Kerbside N 20.63 16.94 19.4 19.18 19.63

13 Whitney Drive Kerbside N 24.48 21.01 20.0 23.29 27.14

14/15/16 Lytton Way Kerbside N 34.11 29.62 30.3 33.1 30.57

17 Hitchin Road Kerbside N 45.51 39.92 41.5 46.20 43.32

18 Fairlands Valley

Park Background N 14.72* 14.76 15.4

18.20 16.96 19 7 Tates Way Kerbside N 32.81* 28.55 30.9 33.87 39.69

20 3 Coreys Mill

Cottages Kerbside N 31.12* 28.64 29.8

33.32 35.86 21 13 Hitchin Road Kerbside N 26.86* 24.33 24.5 27.57 25.99

22 Townsend Mews Kerbside N n/a 21.81 25.9 19.41 25.16

In bold, exceedence of the NO2 annual mean AQS objective of 40µg/m3



2.2.1 Particulate Matter (PM10)

Stevenage Borough Council monitors PM10 at its Continuous Air Quality Monitoring Station on Lytton Way, using a TEOM monitor. This Air Quality Monitoring Station is not representative of relevant exposure. Correction of TEOM data The Volatile Correction Model (VCM) has been applied to all results obtained from the TEOM at Lytton Way (see Appendix A).



Table 2.7 Results of Automatic Monitoring for PM10: Comparison with Annual Mean Objective


AQMA?


Valid Data Capture 2012 % b

Confirm Gravimetric Equivalent (Y or N/A)

Annual Mean Concentration (µg/m3)

2008* c 2009* c 2010* c 2011* c 2012 c

SE1 Roadside N N/A Y Y 21.4 20.7 21.4 17.0 22.0

Table 2.8 Results of Automatic Monitoring for PM10: Comparison with 24-hour Mean Objective


AQMA?


Valid Data Capture 2012 % b

Confirm Gravimetric Equivalent (Y or N/A)

Number of Daily Means > 50µg/m3

2008* c 2009* c 2010* c 2011* c 2012 c

SE1 Roadside N n/a 92.8 Y 8 3 0 14 8



2.2.2 Summary of Compliance with AQS Objectives

Stevenage Borough Council has examined the results from monitoring in the

borough. Concentrations are all below the objectives, therefore there is no need to

proceed to a Detailed Assessment.



3 New Local Developments

Stevenage Borough Council confirms that there are no new or newly identified local

developments which may have an impact on air quality within the Local Authority

area.

Stevenage Borough Council confirms that all the following have been considered:

Road traffic sources

Other transport sources

Industrial sources

Commercial and domestic sources

New developments with fugitive or uncontrolled sources.



4 Local / Regional Air Quality Strategy

Stevenage Borough Council published its Air Quality Strategy in 2006 following consultation with interested parties. This Strategy is available from the Stevenage Borough Council Website, and outlines the Council’s strategic approach to Air Quality. Many of the objectives set out in the strategy have been met, although others are no longer relevant. It is intended that the Strategy be reviewed and updated.



5 Planning Applications

There are no major developments likely to have a significant impact on air quality.



6 Air Quality Planning Policies

Stevenage Borough Council adopted the Stevenage District Plan (2nd Review) in 2004. This plan is in the process of being replaced by a Local Development Framework (LDF) which is a series of documents setting out the statutory development and planning framework for Stevenage. Policies in the District Plan and the emerging LDF direct the promotion of sustainable transport systems, renewable energies and the restriction of hazardous installations. Until such time as the LDF is adopted, the District Plan will remain in effect.



7 Local Transport Plans and Strategies

Hertfordshire County Council have produced a Local Transport Plan, and are currently working in joint partnership with Stevenage Borough Council to develop an Urban Transport Plan (UTP) for Stevenage. The aim of the UTP is to develop a range of transport schemes for all modes of travel that will solve existing problems and prepare Stevenage for future potential growth. It contains policies relating to walking, cycling and passenger transport in addition to making improvements to infrastructure. The Council has specific strategies relating to walking and cycling within the borough. The Cycling strategy was published in 2002, and is currently under review. In addition to this, a Green Transport plan is currently in draft form. Local strategies aim to support the county wide Local Transport Plan, and provide a holistic approach to improving the Borough’s Carbon Footprint.



8 Climate Change Strategies

Stevenage Borough Council published its climate change strategy in May 2009. This document is available on the Council’s website.

A combination of policies aims to reduce our impact on climate change in accordance with the Kyoto Protocol. The continuous monitoring of indicators associated with our policies is reported in our Annual Monitoring Report and Strategic Environmental Assessment. These include indicators such as the number of air quality management areas, nitrogen dioxide levels and particulate levels in the urban area. By monitoring these indicators we are able to assess whether our policies are having a positive effect on air quality and climate change.



9 Implementation of Action Plans

Stevenage Borough Council has not identified any areas of relevant exposure that have exceeded the National Air Quality Objectives and has therefore not been required to declare an Air Quality Management Area. As a result it has not had to develop an Action Plan to improve Air Quality.



10 Conclusions and Proposed Actions

10.1 Conclusions from New Monitoring Data

The results obtained from the Continuous Air Quality Monitoring station over 2012 show that the levels of nitrogen dioxide were broadly comparable with previous years. The levels of PM10 recorded at this site were also broadly comparable, being well below the air quality objective. Results obtained from nitrogen dioxide diffusion tube monitoring do not exceed the Air Quality Objectives at any points of relevant exposure. The bias adjustment factors calculated from local and national co-location studies affect the degree to which the results are below this objective, with the national co-location study producing less favourable results. Only one site exceeds the air quality objective, that at Hitchin Road, a site judged to exhibit no relevant exposure. The three nitrogen dioxide diffusion tubes that were erected mid-2008 to measure relevant exposure along Hitchin Road, have continued to show that levels at this

point are below the Air Quality Objective of 40 g/m3. As a result of this monitoring, it can be concluded that there is currently no requirement for detailed assessment or the declaration of an Air Quality Management Area.



11 References

1. Part IV of Environment Act 1995: Local Air Quality Management. Technical Guidance LAQM.TG (09). Defra, February 2009.

2. The Air Quality (England) Regulations 2000 (Statutory Instrument 2000 No. 928), March 2000.

3. The Air Quality Strategy.for England, Scotland, Wales and Northern Ireland. July 2007. Volume 1 and 2, ISBN 978-0-171692-5

4. The Air Quality Amendment Regulations 2002, ISBN 0 11061468 2.



Appendices

Appendix A: Quality Assurance / Quality Control (QA/QC) Data

Appendix B: Monthly diffusion tube results



Appendix A: QA:QC Data

Factor from Local Co-location Studies (if available)

Local Co-location study: Lytton Road, Stevenage

Roadside site

Local bias adjustment factor 0.86

Diffusion Tube Bias Adjustment Factors

Collated Bias Adjustment Factor: For Gradko tubes, 50% TEA in Acetone, 2011 (version 03/12 of the NO2 tube bias adjustment factor spreadsheet) = 1.01

Discussion of Choice of Factor to Use

A local bias adjustment factor was available for use, but the national figure was used

as this takes account of variations in sampling and reporting. It is more conservative

than the local factor.

PM Monitoring Adjustment

The volatile correction model (VCM) has been used to correct the data. The model

allows the correction of TEOM measurements for the loss of volatile components of

particulate matter that occur due to the high sampling temperatures employed by this

instrument. The resulting corrected measurements have been demonstrated as

equal to the gravimetric equivalent. The Environmental Research Group at Kings

College London has applied the correction model to all PM10 data listed in this

document.

QA/QC of automatic monitoring

The data from our Air Quality Monitoring Station at Lytton Road Stevenage is ratified

up to September 2011 by the Environmental Research Group (ERG) to the HBAQN

network standard. From September 2011, AQDM have been fulfilling the contract.

The data undergoes ‘daily sensibility’ checks 365 days per year, it is then further

ratified on a monthly basis, taking both the two weekly LSO and engineer visits into

account. It is reviewed again as an annual dataset at the end of the year when linear

scaling processes are applied to the data. The data is compared to data collected

from other local network monitoring sites.



The analysers are covered by a service and maintenance contract with Supporting U.

This covers calibration checks, flow and leak checks, cleaning of components,

analyser diagnostic checks and replacement of faulty components and consumables.

The services are carried out on a twice yearly frequency.

All gases used are certified and carry certificates as confirmation as supplied with the

gas by the supplier.

Automatic measurements of PM10 were made using the Tapered Element Oscillating

Microbalance (TEOM) method. Measurements of NOX used were made using the

chemiluminescent method with automatic equipment subject to fortnightly calibration

traceable to National Metrological Standards. All measurements were logged by the

instruments themselves and collected by ERG and AQDM each hour.

Measurements from the monitoring site were validated using the most up to date

calibration factors and publicly disseminated in near real time on the HBAQN web

page formerly www.hertsbedsair.org.uk, now http://www.hertsbedsair.net/.

A final measurement data set to the end of 2012 was produced following

retrospective ratification of the measurements using procedures, which exceed the

requirements detailed in LAQM TG09 (DEFRA, 2009). During ratification information

from regular calibrations, audits and daily manual validation were used to establish

an operational and calibration history of the instruments and the pollution

measurements were corrected to establish traceability to National Metrological

Standards. Details of the monitoring site and the final dataset can be found at

http://www.hertsbedsair.net/.

QA/QC of diffusion tube monitoring

Stevenage Borough Council obtains all nitrogen dioxide tubes from Gradko

International Ltd., who are also responsible for their analysis. The preparation used is

50% T.E.A. in acetone.

In addition, the lab has for many years participated in both the AEA Network Field

Inter-comparison Exercise and WASP scheme.

http://www.hertsbedsair.org.uk/

http://www.hertsbedsair.net/

http://www.hertsbedsair.net/



Data Capture

% Annual Average

Collated bias

adjusted SBC Code Location Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

1 Town Centre 40 44 38 35

27 31 33 40 32 75 26.63 26.90

Gunnels Wood Road x x x x x x x x x x x x

2 Ashdown Road 21 22 24 18 12 10 13 15 17 19 26 26 100 18.52 18.70

3 Monks View 26 31 27 20 14 14 17 19 21 25 29 25 100 22.33 22.55

4 Bedwell Crescent 26 29 18 14 13 16 18 19 24 30 24 92 19.12 19.31

5 Salisbury Road 19 19 20 16 9 10 11 13 13 17 19 20 100 15.53 15.68

6 Letchmore Road 27 24 25 33 11 12 17 20 17 21 32 25 100 22.02 22.24

7 High Street 35 37 18 27 24 27 26 27 35

36 92 24.38 24.62

Control not sited

8 Fishers Green 22 27 29 22 16 14 15 18 15 23 30 24 100 21.17 21.38

9 Magpie Crescent 27 27 31 35 18

21 25 27 28 31 29 83 25.03 25.28

10 Shoreham Close 34 37 38 34 20 22 24 25 28 27 37 33 100 29.88 30.18

11 Newlyn Close 25 25 27 19 14

16 18 20 29 28 83 18.55 18.74

12 Chadwell Road 20 27 28 15 22 14 13 12 14 22 25 21 100 19.44 19.63

13 Whitney Drive 28 30 31 50 14 17 19 22 23 26 35 28 100 26.87 27.14

14 Lytton Way 1 36 37 48 21 21 25 28 25 33 31 41 37 100 32.01 32.33

15 Lytton Way 2 41 41 39 28 20 23 28 34 30 32

83 26.18 26.45

16 Lytton Way 3 33 43 43 27 22 22 29 27 31 33 41 40 100 32.62 32.94

17 Hitchin Road 57 62 30 12 45 31 43 44 48 49 52 42 100 42.90 43.32

18 Fairlands Valley Park 21 25 20 12 9 8 12 13 15 18 25 24 100 16.79 16.96

19 7 Tates Way 45 42 45 39 35 39 35 33 38 38 43 40 100 39.30 39.69

20 3 Coreys Mill Cottages 39 40 40 33 28 32 31 31 37 35 40 40 100 35.50 35.86

21 13 Hitchin Road 28 30 34 25 1 22 25 28 26 28 33 28 100 25.74 25.99

22 Townsend Mews 23 28 31 25 25 18 19 23 24 28 29 26 100 24.91 25.16

NOX Tube Results For Stevenage Borough Council January - December 2012

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