6 Air quality. 6.4 Key data sources referred to in carrying out the air quality assessment include those set out in table 6.1.

Transcription

1 6. Air quality

2 6 Air quality Introduction 6.1 This chapter presents the results of an assessment carried out by RWDI and Gair Consulting Ltd of the impacts on local air quality arising from the construction and operation of the proposed Energy Recovery Facility (ERF) at the proposed development site. 6.2 The proposed development will have potential implications for local air quality through emission to atmosphere principally from the following sources: Construction activities, including vehicle movements Vehicle movements associated with the delivery of waste and the removal of ash The flue gases emitted through the chimney stacks 6.3 In comparison, all other possible sources associated with the proposed development are minor and unlikely to represent a significant impact, although their potential to release pollutants or odours is considered in this report. 6.4 Key data sources referred to in carrying out the air quality assessment include those set out in table 6.1. Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on the incineration of waste Croydon Council (2007) Standards and Requirements for Improving Local Air Quality - Interim Policy Guidance Directive 2008/50/ECof the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe Guidelines for Halogen and Hydrogen Halides in Ambient Air for Protecting Human Health Against Acute Irritancy Effects, EPAQS (February 2006) Addendum to Guidelines for Halogen and Hydrogen Halides in Ambient Air, EPAQS (May 2009) Air Quality Standards Regulations 2010 (SI 2010/2001) Environmental Protection The Air Quality Strategy for England, Scotland, Wales and Northern Ireland Directive 2008/50/EC World Health Organisation WHO, Air quality Guidelines 2000 Guidelines for Metals and Metalloids in Ambient Air for the Protection of Human Health, EPAQS (May 2009) Environment Agency H1 adopted from the UN Economic and Social Council, Executive Body for the Convention on Long-Range Transboundary Air Pollution Environment Agency Horizontal Guidance Note H1, Annex (f) -Air emissions, Version 2.2, August 2010 IAQM (2010) Development Control: Planning for Air Quality (2010 Update) Targeted Application of Calcium Magnesium Acetate (CMA) Pilot Study Monitoring Report, URS Corp Ltd for Transport for London, July UK Soil and Herbage Pollutant Survey, SHS Report 10 Environmental Concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in UK soil and herbage, June 2007 Alloway BJ (1995) Heavy Metals in Soils published by Blackie Academic

3 IAQM (2012) Guidance on the Assessment of Impacts of Construction on Air Quality and the Determination of their Significance v1.1 Environment Agency (2011) Guidance to Applicants on Impact Assessment for Group 3 Metals Stack Releases- V2 June 2011 Defra (2011) Emissions from Waste Management Facilities: Frameworks for Assessment of Data Quality and Research Needs WR 0608 (prepared by Environmental Resources Management Ltd) Table 6.1: Data sources Legislation and policy National policy 6.5 National planning policy, in the form of the National Planning Policy Framework, has relatively little to say about air quality directly. Paragraph 124 notes that compliance with air quality limit values and objectives should be achieved and that the presence of Air Quality Management Areas (AQMAs) should be accounted for. Reference is made to new development in AQMAs being consistent with local action plans for air quality. 6.6 AQMAs are a product of the 1995 Environment Act Part IV, which introduced the concept of Local Air Quality Management (LAQM). This has required local authorities to measure air quality and assess air quality in relation to national air quality objectives. In places where compliance is not achieved, or where compliance is threatened, an action plan must be prepared that defines measures to improve air quality. 6.7 In 1997, the Government adopted its first Air Quality Strategy, setting out an analysis of existing air quality for eight key pollutants and setting out a series of measures to improve concentrations of these pollutants in the future. The Strategy has been successively updated, with the most recent version being published in No specific reference is made to waste management facilities in this document and its references to planning policy have now been overtaken by the introduction of the National Planning Policy Framework. National and European legislation 6.8 Ambient air quality is regulated through European Directives that set limit values on the concentrations of key pollutants. EU limit values have legal force and are intended to apply at all locations where public exposure might occur. The air quality objectives for England and Wales, as set out in the Air Quality Strategy, and are very similar to the EU limit values in most cases, in terms of their threshold concentrations. 6.9 Emissions of some pollutants are regulated at the national level through a number of European Union Directives. The National Emissions Ceilings Directive sets the UK a limit for emission of oxides of nitrogen (NO x ), sulphur dioxide (SO 2 ), ammonia (NH 3 ) and volatile organic compounds (VOCs) The UK is a signatory to the Stockholm Convention on Persistent Organic Pollutants (POPs), first adopted in 2001 and entering into force in POPs are substances that are found in pesticides, industrial chemicals, including poly chlorinated biphenyls (PCBs), and unintentional by products, which

4 include dioxins and furans (known more properly as poly chlorinated dibenzop-dioxins and poly chlorinated dibenzofurans). The Convention seeks to protect the environment from the exposure to POPs by restricting, and ultimately eliminating, their production, use, trade, release and storage Control of industrial emissions is governed by the Industrial Emissions Directive (2010/75/EU), which has yet to be transposed into UK law. This new directive includes seven existing directives, one of which is on Integrated Pollution Prevention and Control (IPPC), which forms the basis for the regulation of industrial facilities, such as the ERF. The IPPC Directive has been implemented in England and Wales through a permitting system, operated by the Environment Agency. In order for an installation to operate legally, the operator must apply for and be granted a permit An application to the Environment Agency for a permit to operate the South London ERF will be made at approximately the same time as planning permission is sought. This allows the Environment Agency to engage fully with on the ERF technology The design and operation of all new waste incineration facilities must ensure compliance with emission limit values (ELVs) set out in the Waste Incineration Directive (WID) recently incorporated into the Industrial Emissions Directive. The Waste Incineration Directive (2000/76/EC) aims to reduce the impact of waste incineration on human health and the environment. The directive applies to incineration and co-incineration plants which burn waste as defined in the Waste Framework Directive. The WID was transposed into UK law via the Waste Incineration (England and Wales) Regulations 2002 (SI 2002 No, 2980), which came into force on 28 December The WID ELVs applicable to the proposed ERF are summarised in table 6.2. Substance Daily mean 30-minute mean 100 th percentile 97 th percentile Particles Nitrogen Dioxide Sulphur Dioxide Carbon Monoxide (b) 150 (c) Hydrogen Fluoride Hydrogen Chloride Total Organic Carbon (TOC) Group I metals - Cd and Tl (d) 0.05 Group II metals - Hg (d) 0.05 Group II metals - Sb, As, Pb, Cr, Co, Cu, Mn, Ni and V (d) 0.5 Dioxins and Furans 0.1 ng I-TEQ m -3 Table 6.2: Waste Incineration Directive Emission Limit Values (mg Nm -3 ) (a) (a) Units are mg Nm -3 (273K, dry and 11% O 2 ) unless stated otherwise (b) 100th percentile of half-hourly average concentrations in any 24-hour period (c) 95th percentile of ten-minute average CO concentrations (d) Average over a sample period between 30 minutes and 8-hours

5 Greater London and London Borough policies 6.14 Through the Mayor s office, London is able to promote distinctive policies on land use planning and air quality that may enhance the objectives of national and European policies The most recent version of the Mayor s Air Quality Strategy was published in December Much of the strategy, and the policies it promotes, is focused on road transport emissions, since this sector contributes most to the air quality problems in London. Waste management does not feature strongly in the strategy, although recognition is given to the fact that some waste management sites in the capital have been shown to be locations where PM 10 concentrations are elevated, sometimes through the re-suspension of street dust by vehicles. The policy adopted is to deploy targeted measures at such locations and this has resulted in dust suppressant being used along some roads where PM 10 concentrations are a problem The London Plan, published in July 2011, sets out the planning policies for the spatial development of London. With regard to air quality, the plan states that development proposals should: Minimise increased exposure to existing poor air quality and make provision to address local problems of air quality Reduce emissions for the demolition and construction of buildings following the best practice guidance in the GLA and London Councils Be at least air quality neutral and not lead to further deterioration of existing poor air quality (such as areas designated as AQMAs) 6.17 These policies are aimed principally at commercial and residential development, where the dominant concerns relate to increased traffic movements, onsite energy generation with biomass boilers and the introduction of new residents into areas of poor air quality The boroughs of Sutton, Croydon and Merton have all responded to the requirements of LAQM and have produced action plans to improve air quality in those parts of the boroughs where AQMAs have been declared. The action plans were first devised and published in and progress on their implementation has been reported in Most of the measures relate to transport, consistent with the causes of non-compliance with air quality standards London councils have produced policy guidance on the improvement of local air quality, part of which is concerned with the assessment of air quality for planning applications. Croydon Council actively promotes this guidance. Methodology 6.20 This section describes the pollutants considered as part of the assessment, the regulations governing ambient air quality, along with the methods used to assess the potential impacts of the proposals and the criteria adopted for defining the significance of impacts.

6 Ambient air quality 6.21 The pollutants considered in the assessment include primarily those that are set out in the Waste Incineration Directive: Fine particles (PM 10 ) The oxides of nitrogen (NO x ) Sulphur dioxide (SO 2 ) Carbon monoxide (CO) Hydrogen fluoride (HF) Hydrogen chloride (HCl) Total organic carbon (TOC) as benzene Dioxins and furans (PCDD/Fs) Trace metals: cadmium (Cd), thallium (Tl), mercury (Hg), antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni) and vanadium (V) Emissions of ammonia (NH 3 ), PM 2.5 (particles of aerodynamic diameter 2.5µm) and polycyclic aromatic hydrocarbons (PAHs) are also considered, for the following reasons: NH 3 is of interest in relation to impacts on habitats, directly and as a component of acid and nutrient nitrogen deposition PM 2.5 has recently become an increasingly prominent air pollutant of interest, with increasing evidence indicating that PM 2.5 is associated with impacts to health. It is now subject to a statutory air quality standard in the UK, following implementation of the European Union s Ambient Air Quality Directive) PAHs have recently become an increasingly prominent air pollutant of interest and one of the key PAH species, benzo[a]pyrene, is subject to a statutory air quality standard in the UK 6.23 In addition, consideration is made of NO 2, PM 10 and PM 2.5 in relation to emissions from development related traffic and emissions of odour during operation of the proposed ERF In relation to impacts on sensitive habitat sites, the potential impacts associated with emissions of NH 3, NO x and SO 2 have been assessed both through impacts directly to air quality and through deposition of acid and nutrient nitrogen The air quality and health technical appendix (Technical Appendix B) sets out in detail the relevant objective / limit values / critical levels, as set out in the Air Quality Strategy, European directives, Environment Agency guidance applicable to each pollutant assessed.

7 Assessment methodology Baseline Air quality 6.26 Automatic monitoring of ambient pollutant concentrations is carried out by LBS and London Borough of Croydon at a number of locations within 5 km of the proposed ERF. A summary of the sites closest to the proposed ERF is presented in table 6.3. London Borough of Merton also operates two roadside automatic monitoring stations around 4 km north west of Beddington Lane. These sites, however, were installed relatively recently and ratified data for a full year are not currently available for either site All of the sites listed in table 6.3 are part of the London Air Quality Network (LAQN) and therefore the data are subject to high levels of quality assurance and control. The location of the monitoring sites with respect to the proposed ERF is presented in figure 6.1. Monitoring site Site grid reference Site type Pollutants measured 1. Croydon- Norbury , Kerbside NO 2 2. Croydon - Thornton Heath , Suburban NO 2, PM 10 (TEOM) 3. Croydon - George Street , Roadside NO 2, PM 10 (TEOM) 4. Croydon - Purley Way , Roadside NO 2 5. Sutton - Wallington , Kerbside NO 2, PM 10 (TEOM) 6. Sutton - Carshalton , Suburban NO 2 7. Sutton - Therapia Lane , Industrial NO 2, PM 10 (TEOM) 8. Sutton - Beddington Lane , Industrial NO 2, PM 10 (TEOM) Table 6.3: LAQN automatic monitoring stations close to the proposed ERF 6.28 Additional automatic monitoring of ambient concentrations of nitrogen oxides (NO x ), particulate matter (as PM 10 ), ammonia (NH 3 ), sulphur dioxide (SO 2 ), nitrogen oxides (NO x ), carbon monoxide (CO), benzene, hydrogen sulphide (H 2 S) and 1,3-butadiene was undertaken by Mouchel at Beddington Lane for a seven month period from May to November The data were compared with concentrations measured at the nearby LAQN monitoring stations and are believed to be of good quality Monitoring of ambient NO 2 concentrations is carried out by London boroughs of Sutton, Merton and Croydon via a network of passive diffusion tubes. Unfortunately, none of the local authority monitoring sites is sufficiently close to the proposed site to be of relevance to the assessment Passive diffusion tube monitoring of NO 2, HCl, HF, SO 2 and VOCs at a number of locations (see table 6.4) in the Beddington Lane area was carried out for a period of approximately six months in 2011 by Mouchel. The location of the tubes is presented in figure 6.2.

8 Site ID Bed M1 Pollutants measured NO 2, SO 2, HCl, HF, VOCs Bed M2 NO 2 Bed M3 NO 2 Bed M4 NO 2 Bed M5 NO2 Bed M6 NO 2, SO 2, HCl, HF, VOCs Bed M7 NO2 Bed M8 NO 2, SO 2, HCl, HF, VOCs Bed M9 NO2 Bed M10 NO2 Bed M11 NO 2, SO 2, HCl, HF, VOCs Bed M12 NO 2, SO 2, HCl, HF, VOCs Bed M13 NO 2, SO 2, HCl, HF, VOCs Bed M14 NO 2 Bed M15 NO 2 Bed M16 NO 2 Bed M17 NO 2 Bed M18 NO 2 Bed M19 NO 2 Table 6.4: Passive diffusion tubes in Beddington 6.31 A BAM automatic analyser was installed at the rear of Archbishop Lanfranc School on Mitcham Road in March This instrument was fitted with a PM 2.5 sampling head and measures concentrations of this pollutant continuously. Insufficient data have been collected at the time of writing to report a credible long term average mean concentration. Soil pollution 6.32 The historical legacy of air pollution at a location can be examined through the measurement of persistent pollutants in the upper layer of undisturbed soil. The presence of metals and persistent organic pollutants such as dioxins is also of relevance in the context of human exposure to such pollutants via the food chain. For these reasons samples of soil have been taken at locations around the development site, in order to quantify the existing concentrations and provide a baseline against which the accumulated future deposition from the ERF can be compared. RWDI took 1 kg samples of soil at each of five locations, as shown in figure 6.3 and described in table 6.5.

9 Site Description and other relevant Grid reference Site name ID information S E N Beddington Park Parkland area, near to sports pitches S E N Poulter Park Recreational area, adjacent to rugby pitch. Housing on the park boundary. S E N Mitcham Common land, used for recreation. Common Samples taken on hill top. Suburban area, with samples taken S E N Pollards Hill from a grassed area with housing nearby and the youth centre. About 50 m from South Lodge Avenue. S E N Wandle Park Public park. Surrounded by housing and with power station about 200 m away Table 6.5: Details of soil sampling sites 6.33 The samples were then sent to Scientific Analysis Laboratories Ltd (SAL), where they were analysed for a selected number of metals, dioxins and furans, dioxin-like poly chlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons. Construction 6.34 Any form of demolition or construction activity has the potential to generate dust emissions and thereby cause annoyance to people in the vicinity of the site. The dust may also contribute to local concentrations of PM 10. Assessing the likelihood and magnitude of such impacts is not straightforward, mainly because it is not possible to quantify the amount of dust emitted and therefore provide a quantitative estimate of the impact in terms of an increase in deposition rate or airborne concentration The Institute of Air Quality Management (IAQM) has recently produced guidance on the assessment of construction on air quality and this guidance forms the basis of the approach taken, and methods adopted for this assessment. The guidance advocates the use of a risk based approach that seeks to identify the scale of the construction activity, the distance to a receptor and the sensitivity of that receptor to air quality impacts. This approach is broadly followed in this assessment. See the following section on significance criteria for further details. Vehicle emissions 6.36 ADMS-Roads (Version 3.1) has been used to assess the air quality impact arising from vehicles associated with the construction and operational phases of the proposed development. ADMS-Roads simulates the dispersion in the atmosphere of pollutants released from industrial and road traffic sources in urban areas. The model simulates the dispersion of emissions using point, line, area and volume source models The model has been used to predict the incremental impact of emissions of NO 2 and PM 10 from road traffic associated with the proposed development for

10 2011 baseline flows and the following scenarios (with and without development traffic): 2015 Peak construction flows and landfill traffic 2017 Operational ERF flows and landfill restoration traffic 2023 Operational ERF flows (and recycling) 6.38 In order to assess the cumulative impact of emissions from the ERF stack and road traffic, the sensitive receptors used in the human health impact assessment have been included in the ADMS-Roads model. In addition, a number of receptors on Beddington Lane have been included which represent residential properties closest to the road (see the air quality technical appendix for details) A summary of the 2011 baseline and 2015, 2017 and 2023 annual average daily traffic (AADT) and development flows on the local road network is presented in the air quality technical appendix. The development flows used here for modeling are an overestimate of the current best estimate by about 3% for 2023 and by 10% for The baseline flows are derived from an automatic traffic count survey carried out to support the Transport Assessment The development is expected to be associated with a traffic flow of 666 two way vehicle movements per day in 2023, when the site is fully operational; lower than the traffic flow associated with current landfill operations at the site (732) The vast majority of the traffic associated with the ERF plant will be HGVs. This is also the case for the existing landfill traffic. The proposed ERF will not significantly affect the number of HGVs on the local road network compared with the existing levels The average vehicular speeds on the identified road links is not expected to change significantly as a result of traffic associated with the ERF. Vehicle speeds for the road links have been derived from the ATC data The ADMS-Roads model has been run using hourly sequential meteorological data from Gatwick Airport for This year was identified as producing the highest ground-level pollutant concentrations in the dispersion modelling assessment of emissions from the ERF and has therefore been chosen for consistency. Stack emissions 6.44 The largest source of emissions to atmosphere will be the gases emitted to atmosphere through the two main chimney stacks. These gases will leave the chimney in a plume that subsequently disperses in the atmosphere and dilutes the concentrations of the pollutants it contains. The physical processes that govern this dispersion process can be simulated with a dispersion model, leading to the quantification of impacts in terms of airborne concentrations at ground level and deposition rates to the underlying surface.

11 6.45 The primary dispersion model used in this assessment was ADMS 4, a well known model and one whose use is recognised by the Environment Agency, amongst others. The model requires inputs for: Meteorological conditions hour by hour Terrain Significant building dimensions Emissions 6.46 Further details on these inputs are set out in the air quality technical appendix A modelling exercise was completed using preliminary emission data in order to derive a suitable stack height. Model runs were carried out using stack heights in the range 60 m to 100 m, at 5 m intervals. The results were expressed in terms of the annual mean concentrations of NO 2, at the point of maximum impact. The results are summarised in the air quality technical appendix and demonstrate that a stack height of 85m is best The dispersion modelling was also used to consider the potential impacts on local habitat receptors, and each site of conservation importance identified in the baseline was assigned a critical level for the airborne concentration of either NO x, SO 2, hydrogen fluoride or ammonia, and a critical load for acid or nutrient nitrogen deposition. Significance criteria 6.49 Significance criteria in air quality assessments have not been in common use or widely agreed until quite recently, when the Institute of Air Quality Management and Environmental Protection UK produced some guidance on the subject (see table 6.1). This advice has been used as the basis for the criteria adopted here and adapted such that it is consistent with the significance criteria used in some of the other sections of the ES The first step is to describe the magnitude of the impact of a given pollutant, set out below in table 6.6. Magnitude of change Annual mean concentration change (PC) Large Increase or decrease > 10% Medium Increase or decrease 5-10% Small Increase or decrease 1-5 % Imperceptible Increase or decrease < 1% Table 6.6: Magnitude of change descriptors 6.51 The change in air quality is then compared with the existing air quality and the relevant air quality standard or assessment criterion for each pollutant, to determine the degree of effect (negligible, slight, moderate or substantial) and from this ascribe significance. An effect is either not significant or significant; these aspects are set out below in table 6.7, assuming that the impact is adverse.

12 Absolute value (PEC) PEC above AQS with scheme PEC just below AQS with scheme PEC below AQS with scheme (at 75%-90% of AQS) PEC well below AQS with scheme (at < 75% of AQS) Magnitude of PC change Imperceptible Small Medium Large Negligible Slight Moderate Substantial Not significant Not significant Significant Significant Negligible Negligible Moderate Moderate Not significant Not significant Significant Significant Negligible Not significant Negligible Not significant Negligible Not significant Negligible Not significant Table 6.7: Assessing the degree of effect and significance Slight Not significant Negligible Not significant Slight Not significant Slight Not significant 6.52 Thus, on the basis of these criteria, the increase in concentration or deposition rate of a pollutant has to be 5% or greater of the relevant assessment criterion for the impact to be described as significant. This is less stringent than the initial Environment Agency (EA) test to determine whether an impact is definitively not significant, where the test is 1% of the assessment criterion for long term average concentrations (but 10% for short term concentrations). However, the EA test then goes on to examine the impact relative to the PEC and if the PEC is less than 70% of the criterion, then the impact is deemed to be not significant. When the full EA test is considered, the scheme used for this air quality assessment is therefore very similar to the criterion used in environmental permitting and set out in Horizontal Guidance Note H The EA criterion for significance has been adopted in this assessment for the specific case of habitats, since the EA guidance on the subject is the only one available and is recognised as such. Baseline Local authority review and assessment 6.54 Local authorities are required to periodically review and assess the current and future quality of air in their areas. Where it is determined that an air quality objective is not likely to be met within the relevant time period, the authority must designate an AQMA and produce a local action plan The early stages of the review and assessment process carried out by LBS highlighted elevated concentrations of NO 2 and PM 10 arising from road traffic in congested areas. Consequently, an AQMA for these pollutants was declared in March 2001 along the majority of the main roads in the borough. The AQMA was extended in 2004 to include two additional roads (including Beddington Lane) on the basis of measured exceedences of the air quality objectives The proposed ERF is around 800 m south and 500 m west of the boundaries with the London boroughs of Merton and Croydon respectively. Both

13 councils have declared borough-wide AQMAs for NO 2 (Merton Council s AQMA is also for PM 10 ) The LBS is predominantly residential, but with two main industrial areas -; Beddington in the north east of the borough and a smaller area in West Sutton. The Beddington Lane industrial area comprises a variety of light and heavy industrial units, including a number of waste management facilities. Emissions from these installations are believed to be a significant source of airborne PM 10. Local monitoring data shows that concentrations of PM 10 in the area are elevated, but the air quality objectives are not currently being exceeded. An AQMA for NO 2 was declared in 2010 to limit further deterioration of air quality as a result of future development in the area The Beddington Lane AQMA extends from the boundary with London Borough of Merton in the north and borough of Croydon in the east. To the south, it extends down to Richmond Road and along the northern edge of Beddington Park. The western boundary extends to London Road and captures the whole of the Beddington Farmlands Landfill Site and sludge lagoons. The boundary of the Beddington Lane AQMA is illustrated in figure Beddington Lane may also be included in the Mayor of London s Dust Suppression Trial. This involves spraying roads with a biodegradable saline solution, which binds particulate matter to the carriageway, preventing resuspension. Trials on Victoria Embankment and Marylebone Road showed that the airborne particle concentration was reduced by around 10% over a 24 -hour period. Ambient air quality Concentrations of fine particles (PM 10 and PM 2.5 ) 6.60 A summary of concentrations of PM 10 (gravimetric equivalent) measured at LAQN monitoring sites from 2009 to 2011 is presented in table 6.8. Annual mean (µg m -3 Number of 24 hour means ) Monitoring Site > 50 µg m Croydon- Thornton Heath - (a) (a) Croydon - George Street 24 - (a) (a) Sutton - Wallington (a) (a) 7. Sutton - Therapia Lane - (b) - (b) 27 - (b) - (b) Sutton - Beddington Lane Air Quality Objective Table 6.8: LAQN measured PM 10 concentrations ( ) Data capture below 90% Site not operational 6.61 Measured annual mean PM 10 concentrations are well within the annual mean air quality objective of 40 µg m -3 at all of the LAQN sites. The highest annual mean concentration over the past three years was measured at Beddington Lane at 29 µg m -3, 73% of the objective. The number of exceedences of the

14 24-hour mean objective was within the 35 allowed at all sites. Again, the highest 24-hour means were measured at the two sites within the Beddington Lane industrial area PM 10 concentrations have also been measured by Mouchel close to the site of the proposed ERF from 23rd May to 30th November During this period the mean PM 10 concentration was 34.8 µg m -3, which compared well with the LAQN monitoring data over the same period For comparison, ambient background concentrations of PM 10 and PM 2.5 for 2011 have been obtained from the Defra UK Background Air Pollution Maps. The mapped PM 10 and PM 2.5 concentrations for the area surrounding the proposed ERF are presented as contour plots in the air quality technical appendix. The mapped background PM 10 concentrations are in reasonable agreement with concentrations measured at the suburban monitoring site at Thornton Heath, Croydon. At Beddington Lane, the mapped background PM 10 concentration is around 18 µg m -3, which suggests that local sources contribute up to 10 µg m -3 of the total annual mean concentration at this location For the purposes of this assessment it is appropriate to use a concentration of PM 10 that is representative of urban background exposure. The Therapia Lane and Beddington Lane monitoring sites are located within or on the edge of the Beddington Lane industrial area and will not necessarily be representative of public exposure. Therefore, for the purposes of the assessment the annual mean PM 10 concentration for public exposure is taken as the mean of the 2011 concentrations measured at the four monitoring locations, 25 µg m Until information on background PM 2.5 concentrations over an extended period becomes available, it is assumed that the baseline PM 2.5 concentration is 55% higher than the mapped background (as for PM 10 ) at approximately 19 µg m -3, 76% of the EU limit value of 25 µg m -3. Concentrations of nitrogen dioxide (NO 2 ) 6.66 A summary of concentrations of nitrogen dioxide (NO 2 ) measured at LAQN monitoring sites from 2009 to 2011 is presented in table 6.9. Monitoring site Annual mean (µg m -3 Number of 1 Hour means ) > 200 µg m Croydon- Norbury Croydon - George Street (a) (a) 4. Croydon - Purley Way 44 - (a) - (a) 0 - (a) - (a) 5. Sutton - Wallington (a) Sutton - Carshalton Sutton - Therapia Lane - (b) - (b) - (a) - (b) - (b) - (a) 8. Sutton - Beddington Lane 42 - (a) (a) 0 Air Quality Objective Table 6.9: LAQN measured NO 2 concentrations ( ) Data capture below 90% Site not operational

15 6.67 There are widespread exceedences of the annual mean NO 2 objectives at the majority of the LAQN monitoring sites identified in table 6.3, which is not surprising, since most are roadside sites measuring the direct influence of road traffic. Concentrations measured at Beddington Lane are close to the annual mean objective, with an exceedence measured in The short-term NO 2 objective is met at all of the sites except Wallington and Norbury NO 2 concentrations have also been measured close to the site of the proposed ERF in three periods within the overall period of 18th May to 30th November During this period, the average NO 2 concentration was 29.8 µg m -3, which is considerably lower than the annual mean concentration measured at the LAQN Beddington Lane monitoring station in 2011, of 37 µg m -3. This may reflect the low level of data capture of around 57% for NO 2 over the three monitoring periods. In addition, the monitoring took place over the summer months when NO 2 concentrations are typically lower than in the winter months A summary of period mean NO 2 concentrations measured by diffusion tube at sites around the proposed development site from 23rd May to 12th September 2011 is presented in the air quality technical appendix. The period mean NO 2 concentration is above the annual mean objective of 40 µg m -3 at four of the 19 Beddington diffusion tube locations. All four sites are adjacent to busy carriageways. The period mean measured by diffusion tube on Beddington Lane (M9) is in good agreement with that measured by the nearby Beddington Lane LAQN automatic monitoring station over the whole year, although the diffusion tube further south on Beddington Lane (M10) shows a much higher concentration Concentrations measured on Beddington Lane will not be representative of the baseline NO 2 concentration at the majority of the sensitive receptors considered in the assessment. The average of concentrations measured at diffusion tubes located in residential areas (M2, M3, M4, M5, M12 and M13) may provide a more appropriate indication of the urban background concentration at receptor locations. The average concentration measured at these sites over the monitoring period was 30.8 µg m -3, which is 77% of the annual mean air quality objective The Defra mapped annual mean NO 2 concentrations for the area surrounding the proposed ERF plant is around 21 µg m -3. This figure compares well with the concentration measured at the temporary automatic monitoring station, but is significantly lower than that measured by the LAQM monitoring station on Beddington Lane and many of the diffusion tube locations which are closer to road traffic and therefore not representative of the background. Sulphur dioxide (SO 2 ) 6.72 Continuous monitoring of sulphur dioxide (SO 2 ) concentrations is not routinely undertaken by Sutton, Croydon or Merton. Monitoring carried out at urban background sites in Wandsworth and Lewisham indicates that short term concentrations are well within the SO 2 objectives and there have been no reported exceedences in recent years.

16 6.73 Automatic monitoring of SO 2 was carried out close to the proposed site from 19th May to 4th July The mean concentration measured during this period was 5.4 µg m -3, with a maximum hourly mean of 28.6 µg m -3. The maximum measured hourly mean concentration is just 8.2% of the hourly mean air quality objective of 350 µg m Diffusion tube monitoring of SO 2 has been carried out at six locations in the Beddington Lane area. The tubes were exposed for two week periods and therefore the data are not appropriate for comparison with the short term air quality objectives for the protection of health. A summary of the period mean of concentrations measured between 23rd May and 11th October 2011 is presented in table Site Number of tubes Period mean SO 2 concentration (µg m -3 ) Bed M1 Triplicate 2.5 (a) Bed M6 Singular 2.5 Bed M8 Singular 1.7 Bed M11 Singular 2.0 Bed M12 Singular 2.9 Bed M13 Singular 5.2 Table 6.10: Period mean concentrations of SO 2 measured by diffusion tube around Beddington Lane Average of triplicate tubes 6.75 The period mean concentrations are well within the long term (annual mean) SO 2 objective of 20 µg m -3 set for the protection of sensitive habitats and ecosystems. The average SO 2 concentration measured by diffusion tube is 2.8 µg m -3, just over half the concentration measured at the temporary automatic monitoring station The Defra mapped annual mean SO 2 background concentration in the area is around 3.5 µg m -3. This figure compares well with the diffusion tube and automatic monitoring data and is assumed to provide a reasonable estimate of baseline SO 2 concentrations at sensitive receptor locations. Carbon monoxide (CO) 6.77 Continuous monitoring of carbon monoxide (CO) concentrations is not routinely undertaken by Sutton, Croydon or Merton. Automatic monitoring of CO was undertaken for close to the proposed site from 8th June to 30th November The mean concentration measured over this period was 300 µg m -3, with a maximum hourly mean of 6,400 µg m -3. The maximum hourly mean concentration was well within the short term (8 -hour mean) objective for CO of 10,000 µg m The Defra mapped background annual mean CO concentration in the area is around 200 to 210 µg m -3, which is in good agreement with the period mean measured close to the proposed site. Therefore, an annual mean concentration of 205 µg -3 is assumed to provide a reasonable estimate of CO concentrations at nearby sensitive receptors.

17 Hydrogen fluoride (HF) 6.79 Monitoring of ambient concentrations of hydrogen fluoride (HF) by passive diffusion tube was carried out at six locations around Beddington Lane from 23rd May to 12th October A summary of the mean concentrations measured over this period is presented in table Site Number of tubes Period mean HF concentration (µg m -3 ) Bed M1 Triplicate 2.4 (a) Bed M6 Singular 3.1 Bed M8 Singular 4.3 Bed M11 Singular 3.5 Bed M12 Singular 3.2 Bed M13 Singular 2.5 Table 6.11: Period mean concentrations of HF measured by diffusion tube around Beddington Lane (a) Average of triplicate tubes 6.80 These measurement data suggest that the average baseline HF concentration at the development site and nearby sensitive receptor locations is likely to be around 3 µg m -3, which is not consistent with the anthropogenic background concentration quoted in the EPAQS Guidelines for Halogen and Hydrogen Halides in Ambient Air. This source suggests that only in heavily industrialised areas within Europe are background concentrations in the range 0.5 to 2 µg m -3, with measurements in the UK showing long term average concentrations below this level, even near industrial sources. The measurement data have been taken as being unreliable and instead a value for the background concentration has been adopted that is at the pessimistic extreme of national estimates. Hydrogen Chloride (HCl) 6.81 Monitoring of ambient concentrations of hydrogen chloride (HCl) by passive diffusion tubes was carried out at six locations around Beddington Lane from 23rd May to 12th October A summary of the mean concentrations measured over this period is presented in table Site Number of tubes Period mean HCl concentration (µg m -3 ) Bed M1 Triplicate 8.8 (a) Bed M6 Singular 15.4 Bed M8 Singular 9.0 Bed M11 Singular 8.8 Bed M12 Singular 9.3 Bed M13 Singular 10.1 Table 6.12: Period mean concentrations of HCl measured by diffusion tube around Beddington Lane (a) Average of triplicate tubes 6.82 These measurement data suggest that the baseline HCl concentration at the site is likely to be around 10 µg m -3, which seems to be a highly implausible result, given our understanding of background HCl concentrations in the UK.

18 The EPAQS report notes that the rural measurements made in the UK as part of Defra s network indicate annual average concentrations in the range µg m -3. On balance, these reported measurements are more likely to be representative of the Beddington area than the diffusion tube measurements. For this reason, a value of 1 µg m -3 has been adopted as the annual average background concentration for the assessment Ambient monitoring of HCl is carried out as part of the Defra Acid Gases and Aerosol Monitoring Network (AGANet) at 30 locations around the UK. However, all of the monitoring sites are rural and therefore unlikely to be entirely representative of background concentrations at the site. In 2009 annual mean concentrations of HCl in the network ranged from to 0.49 µg m -3, considerably lower than the period mean concentration measured at Beddington Lane. Volatile organic compounds (VOCs) 6.84 Continuous monitoring of benzene concentrations is not routinely undertaken in Sutton, Croydon or Merton, although automatic monitoring of this pollutant was undertaken by Mouchel close to the proposed site from 5th July to 30th November The mean benzene concentration measured over this period was 0.2 µg m -3, with a maximum hourly mean of µg m -3. The average concentration is well within the long term air quality objective/ EU limit value of 5 µg m Monitoring of ambient VOC concentrations by passive diffusion tubes was carried out at six locations around Beddington Lane from 23 May to 11 October The average benzene concentration over this period was 0.72 µg m -3 (data capture < 90%). The concentration of 1,3-butadiene was consistently below the detection limit The Defra mapped 2010 background benzene concentration at the proposed ERF is around 0.65 µg m- 3, which is just 4.0% of the annual mean objective concentration of 5 µg m -3. The estimated background concentration is in good agreement with that measured by diffusion tubes close to the proposed site. Therefore, in the absence of better quality site specific monitoring data, the mapped background is assumed to provide a reasonable estimate of baseline concentrations at the site. Dioxins and furans 6.87 Monitoring of PCDD/Fs is currently carried out by Defra at six locations in the UK (Hazelrigg, High Muffles, London, Manchester, Auchencorth Moss and Middlesbrough). Hazelrigg and Auchencorth Moss are described as semirural and rural sites respectively and the remaining four sites are in urban locations To provide an indication of the range of PCDD/F concentrations that occur in the UK, a summary of the annual mean concentrations measured between 2006 and 2008 is presented in table 6.13 (more recent data have not yet been reported).

19 Year London Manchester Auchencorth Moss Middlesbrough High Muffles Hazelrigg Table 6.13: Summary of UK annual mean PCDD/F concentrations from 2006 to 2008 (fg m 3) (a) Where 1 fg m 3m 3 (femtogram per cubic metre) is equivalent to 1 x g m 3m 3 or 1 x 10 9 µg m The average concentration measured in central London from 2006 to 2008 was 8.0 fg m 3m 3 and this is assumed to be reasonably representative of the baseline dioxin and furan concentration at the proposed ERF. Trace metals 6.90 Monitoring of trace elements has been undertaken by the Defra since Currently monitoring of 12 metals is carried out at 24 predominantly urban locations. In addition, concentrations of arsenic, cadmium, mercury and nickel are monitored at a further 10 rural locations. To provide an indication of the range of trace metal concentrations that may occur in London, measured concentrations at Cromwell Road and Horseferry Road are summarised in table Metal Cromwell Road Horseferry Road Assessment Criterion (ng m 3 ) (ng m 3 ) (ng m 3 ) Antimony (Sb) Not measured Not measured 5,000 Arsenic (As) Cadmium (Cd) Total chromium (Cr) (a) 5000 (b) Cobalt (Co) Not measured Not measured 1,000 Copper (Cu) ,000 Lead (Pb) Manganese (Mn) Mercury (Hg) (c) Nickel (Ni) Thallium (Tl) Not measured Not measured 1,000 Vanadium (V) ,000 Table 6.14: Range of annual mean trace metal concentrations (2007 to 2009) (a) Hexavalent chromium (CrVI) (b) Trivalent chromium (CrIII) (c) Total particulate and vapour 6.91 The average of the trace metal concentrations measured at both sites is assumed to provide a reasonable estimate of the baseline concentration in the vicinity of the proposed ERF and nearby sensitive receptors.

20 Ammonia (NH 3 ) 6.92 Ambient concentrations of ammonia (NH 3 ) are measured at 95, largely rural, locations by the National Ammonia Monitoring Network. The closest monitoring site to Beddington Lane is at Cromwell Road in South Kensington. The average NH 3 concentration measured over the last three years at this site was 3.3 µg m -3, which is just above the critical level for the protection of sensitive habitats and ecosystems of 3.0 µg m Automatic monitoring of NH 3 concentrations was undertaken close to the proposed site from 30th September to 30th November The mean NH 3 concentration over this period was 4.2 µg m -3, with a maximum hourly mean of 31 µg m -3. Summary of background concentrations 6.94 A summary of the annual mean background concentrations used in the assessment is presented in table In selecting values for the individual pollutants, professional judgment has been applied to the available data in order to propose numbers that are representative of the urban background, to which most of the receptors are likely to be exposed, and which are not overly precise, e.g. 3 µg m -3 and not 3.3 µg m -3. Given the high degree of spatial variability of concentrations for those pollutants associated with road traffic, notably NO 2, it must be recognised that these estimates will not be uniform across the assessment area.

21 Pollutant Annual mean Short-term Particles (PM 10 ) 25 µg m µg m -3 (e) Particles (PM 2.5 ) 19 µg m -3 n/a Nitrogen Dioxide (NO 2 ) 30 µg m (d) Sulphur Dioxide (SO 2 ) 3.5 µg m -3 7 (d) (d)(e) 9 (d)(g) Carbon Monoxide (CO) 205 µg m (d)(f) Hydrogen Fluoride (HF) 0.5 µg m -3 1 (d) Hydrogen Chloride (HCl) 1 µg m -3 2 (d) Ammonia (NH 3 ) 3 µg m 3 - Benzene (C 8 ) 0.65 µg m -3 n/a 1,3,-Butadiene 0.28 µg m -3 n/a Dioxins and Furans (PCDD/Fs) 8.0 fg m -3 (b) n/a Cadmium (Cd) 0.2 ng m -3 (c) n/a Thallium (Tl) No data available - Mercury (Hg) 2 ng m -3 (c) 5ng m -3 (c)(d) Arsenic (As) 0.8 ng m -3 (c) n/a Chromium (Cr) 3 ng m -3 (c) 6. ng m -3 (c)(d) Cobalt (Co) No data available - Copper (Cu) 30ng m -3 (c) 61 ng m -3 (c)(d) Lead (Pb) 11 ng m -3 (c) n/a Manganese (Mn) 8ng m 3 (c) 16 ng m -3 (c)(d) Nickel (Ni) 2 ng m -3 (c) n/a Antimony (Sb) No data available - Vanadium (V) 3ng m -3 (c) 3 ng m -3 (c)(e) Table 6.15: Summary of background concentrations (a) Where background concentrations are expressed as range (e.g. Arsenic) the average concentration has been used (b) Units are fg m -3 (femtogram per cubic metre) equivalent to 1 x grams per cubic metre (c) Units are ng m -3 (nanogram per cubic metre) equivalent to 1 x 10-9 grams per cubic metre (d) 1 hour mean background concentration estimated by multiplying the annual mean by a factor of 2 in accordance with the H1 Guidance (e) 24 hour mean background concentration estimated by multiplying the 1-hour mean by a factor of 0.59 in accordance with the H1 Guidance (f) 8 hour mean background concentration estimated by multiplying the 1-hour mean by a factor of 0.70 in accordance with the H1 Guidance (g) 15 minute mean background concentration estimated by multiplying the 1-hour mean by a factor of 1.34 in accordance with the H1 Guidance. Odour 6.95 The existing waste management activities on the site, coupled with the local sewage treatment works, have been possible causes of odour complaints in the past. Future baseline 6.96 It is anticipated that air quality in 2017 and beyond will be at least as good as it is now, if not better, as national and local policies relating to vehicle

22 emission performance will tend to reduce airborne concentrations of pollutants such as NO 2 and PM 10. Pollutants in soils 6.97 Dioxin and furan concentrations at the five sites, expressed as I-TEQ (see the air quality technical appendix for an explanation of this measurement) are shown in table Concentrations of dioxins/furans measured in soil around the proposed EWF location are in the range 2.1 to 6.4 ng I-TEQ kg -1. All of these are well within the expected range for urban background concentrations in England and are not substantially different from the median value for rural soils in England. Site Soil concentration S1 Beddington Park 3.4 S2 Poulter Park 3.3 S3 Mitcham Common 6.4 S4 Pollards Hill 2.1 S5 Wandle Park 6.1 Typical England Rural Background Concentrations (a) Median: 2.53 Typical England Urban Background Concentrations (a) Median Table 6.16: Dioxin/Furan concentrations in soil samples (ng I-TEQ kg -1 ) (a) UK Soil and Herbage Pollutant Survey, SHS Report 10 Environmental Concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in UK soil and herbage, June Table 6.17 shows the total concentrations for 12 PCBs measured at the five sites. They are expressed as upper bound, because, for some of the individual PCBs, the concentrations were below the limit of detection and the value for this in such cases has been used in compiling the aggregate value. When compared with the aggregate value the EA reported for a total of 27 PCBs, the measured values are very similar and do not indicate any notable historical pollution. There are 209 known PCBs in total, and the laboratory tested for the 12 that the World Health Organization recommends monitoring, because of their dioxin like behaviour. Site Soil concentration, upper bound S1 Beddington Park < 0.78 S2 Poulter Park <0.80 S3 Mitcham Common <1.17 S4 Pollards Hill <0.50 S5 Wandle Park <1.09 Typical England Rural Background Concentrations (a) Median: 0.97 Typical England Urban Background Concentrations (a) Median 2.52 Table 6.17: PCB concentration in the soil samples (µg kg-1) as a grand total (a) UK Soil and Herbage Pollutant Survey, SHS Report 9 Environmental Concentrations of polycyclic aromatic hydrocarbons in UK soil and herbage, June