ENERGY RECOVERY FACILITY KINGSWOOD, CANNOCK

AIR QUALITY – TECHNICAL APPENDIX 6/1 ATMOSPHERIC DISPERSION MODELLING SLR Ref: 402.0034.00320

July 2010 SLR Ref: 402.0034.00320

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CONTENTS 1.0 INTRODUCTION ...... 1 1.1 Scope ...... 1 1.2 Structure of Report ...... 1 2.0 POLICY, LEGISLATION AND RELEVANT GUIDANCE ...... 2 2.1 Ambient Air Quality ...... 2 2.2 Environmental Permitting Regulations ...... 4 2.3 Regulation of Industrial Processes ...... 6 2.4 Impacts on Sensitive Ecosystems ...... 7 3.0 ASSESSMENT METHODOLOGY...... 10 3.1 Dispersion Modelling ...... 10 3.2 Assessment of Impacts on Human Receptors ...... 11 3.3 Assessment of Impacts on Vegetation and Ecosystems ...... 11 4.0 BASELINE ENVIRONMENT ...... 14 4.1 Site Location ...... 14 4.2 Existing Local Sources ...... 14 4.3 Local Air Quality Management ...... 15 4.4 Background Levels and Predictions ...... 16 4.5 Baseline Monitoring ...... 19 4.6 Summary of Applied Background Concentrations ...... 21 4.7 Sensitive Receptors: Human ...... 22 4.8 Sensitive Receptors: Ecological ...... 22 4.9 Meteorological Conditions ...... 25 4.10 Topography ...... 26 5.0 QUANTIFICATION OF EMISSIONS TO ATMOSPHERE ...... 27 5.1 Sources of Emission ...... 27 5.2 Concentration of Emissions ...... 27 5.3 Process Conditions ...... 28 5.4 Applied Emission Rates ...... 29 5.5 Dispersion Model Set-up ...... 29 6.0 PREDICTION OF IMPACTS ...... 33 6.1 Predicted Short-term Impacts ...... 33 6.2 Predicted Long-term Impacts...... 35 6.3 Results –Sensitive Ecosystems ...... 37 6.4 Plume Visibility ...... 40 7.0 DISPERSION MODEL SENSITIVITY ...... 41 7.1 Stack Height Variation ...... 41 7.2 Atmospheric Chemistry...... 42 7.3 Typical MSW ERF Emissions ...... 42 7.4 Accident Scenarios (Abnormal Events) ...... 43 7.5 Annual Operating Hours ...... 47 7.6 Assessment of Model Sensitivities ...... 47 8.0 CUMULATIVE IMPACTS ...... 49 8.1 Four Ashes (W2R) EfW ...... 49 8.2 Poplars AD Facility ...... 50 8.3 Poplars LFG Utilisation Plant ...... 51 8.4 Road Traffic: Cumulative Impacts ...... 52

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TABLES Table 2-1 UKAQS Air Quality Standards (Human Health) ...... 2 Table 2-2 Additional Air Quality ‘Target Values’ ...... 3 Table 2-3 WID Emission Limit Values ...... 5 Table 2-4 Relevant EALs (µg/m3) ...... 6 Table 2-5 Critical Levels For The Protection Of Vegetation And Ecosystems ...... 7 Table 3-1 Applied Deposition Velocities ...... 12 Table 3-2 Applied Deposition Conversion Factors ...... 12 Table 3-3 Applied Acidification Conversion Factors ...... 12 Table 4-1 Existing Local Emissions within surrounding 1km grid squares of the Proposed Development (2007) ...... 14 Table 4-2 Automatic Monitoring Data: Annual Mean (µg/m3) ...... 16 Table 4-3 Automatic Monitoring Data: Annual Mean (µg/m3) ...... 16 Table 4-4 17 Table 4-5 Heavy Metals Monitoring Data Walsall Centre (annual average g/m3) ...... 18 Table 4-6 Annual Mean Concentrations of HCl (µg/m3) at Sutton Bonington ...... 18 Table 4-7 Monitoring Calendar for Year 2009 ...... 19 Table 4-8 Location of Diffusion Tubes for Baseline Assessment ...... 19 3 Table 4-9 NO2 Diffusion Tube Monitoring Results (µg/m ) ...... 20 Table 4-10 Baseline Diffusion Tube Monitoring Results (µg/m3) ...... 20 Table 4-11 Applied Background Concentrations ...... 21 Table 4-12 Designated Sites within Zone of Influence of the Study Area ...... 22 Table 4-13 Existing Levels of Deposition at Ecological Receptors (source: APIS) ...... 23 Table 4-14 24 Table 4-15 26 Table 5-1 Emission Characteristics from Stack ...... 28 Table 5-2 Emission Rates from Kingswood ERF (per line) ...... 29 Table 5-3 Met Data Preparation – Applied Surface Characteristics ...... 31 Table 6-1 Predicted Short-term Process Contributions PC (µg/m3) ...... 33 Table 6-2 Predicted Short-term Predicted Environmental Concentrations (PEC) (µg/m3) ...... 35 Table 6-3 Predicted Long-term Process Contributions (µg/m3) ...... 35 Table 6-4 Predicted Long-term Predicted Environmental Concentrations (µg/m3) ...... 36 Table 6-5 Predicted Nitrogen Oxide Impacts on Sensitive Ecosystems (µg/m3) ...... 37 Table 6-6 Predicted Sulphur Dioxide Impacts on Sensitive Ecosystems (µg/m3) ...... 37 Table 6-7 Predicted Ammonia Impacts on Sensitive Ecosystems (µg/m3) ...... 38 Table 6-8 Predicted HF Impacts on Sensitive Ecosystems (µg/m3) ...... 38 Table 6-9 Predicted Acid Deposition on Sensitive Ecosystems (kgeq/hr/yr) ...... 38 Table 6-10 Predicted Nitrogen Deposition on Sensitive Ecosystems (kg/hr/yr) ...... 39 Table 7-1 Typical ERF Emission Rates ...... 42 Table 7-2 Plausible Abnormal Emissions from an ERF ...... 45 Table 7-3 Short-term Impacts Resulting from Plausible Abnormal Emissions (µg/m3) 45 Table 7-4 Long-term Impacts Resulting from Plausible Abnormal Emissions (µg/m3) 46 Table 7-5 Results of Model Sensitivity Assessment ...... 47 Table 8-1 Emissions from the W2R Facility...... 49 Table 8-2 Emissions from 120000tpa AD Facility ...... 50 Table 8-3 Emissions from LFG Engines ...... 51 Table 8-4 Impacts on Watling Street (PC) ...... 52

FIGURES Figure 4-1 Watling Street, Bridgtown AQMA ...... 15 Figure 4-2 Windrose for Coleshill Observing Station (2004 – 2008) ...... 25 Figure 6-1 Cannock Chase SAC Critical Load Function ...... 39

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Figure 7-1 Stack Height Implications –NO2 ...... 41

DRAWINGS

Drawing 01 Diffusion Tube Locations

Drawing AQ1 Predicted long-term NO2 Impacts Drawing AQ2 Predicted long-term TOC Impacts Drawing AQ3 Predicted long-term Nickel Impacts Drawing AQ4 Predicted long-term Cadmium Impacts Drawing AQ5 Predicted long-term Arsenic Impacts Drawing AQ6 Predicted Long-term Chromium VI Impacts

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1.0 INTRODUCTION

This air quality assessment has been undertaken in support of an Environmental Impact Assessment (EIA) for a proposed Energy Recovery Facility (ERF) at Kingswood near Cannock, Staffordshire.

Biffa Waste Services Limited (Biffa) is proposing to develop a facility that would treat 400,000 tonnes of residual non-hazardous waste per annum which will be equipped with two process lines (Lines 1 and 2).

This report presents the detailed atmospheric dispersion modelling undertaken in relation to emissions from stacks serving the thermal waste treatment process and forms a technical appendix to the Air Quality Section of the Environmental Statement (ES).

1.1 Scope

This assessment quantifies and assesses the resultant impacts from the proposed ERF facility using Environment Agency approved techniques against published standards for the protection of human health and sensitive ecological receptors.

1.2 Structure of Report

The remainder of this report is structured as follows:

 Section 2 provides a summary of the legislation and guidelines relevant to the proposed activities at the site;  Section 3 details the methodology applied in undertaking the assessment;  Section 4 provides a description of the surrounding environment, including the identification of potentially sensitive receptors and a description of local climate and air quality conditions;  Section 5 details how the emission rates and discharge characteristics from the installation have been calculated;  Section 6 provides a detailed description of the dispersion modelling inputs reports the predicted potential impacts of the existing and proposed operations on air quality; and  Section 7 assesses the sensitivity of the dispersion model and the effect on predicted impacts.  Section 8 presents an assessment of cumulative impacts.

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2.0 POLICY, LEGISLATION AND RELEVANT GUIDANCE

2.1 Ambient Air Quality

2.1.1 (National) Air Quality Strategy

The ‘Air Quality Strategy for England, Scotland, Wales and Northern Ireland’ (UKAQS) was first published in 2000 and updated with an addendum in February 2003. Following extensive consultation and developments in the applicable Regulations, the Strategy has been updated and a revised Air Quality Strategy1 was released by in July 2007.

The UKAQS sets out a comprehensive strategic framework within which air quality policy will be taken forward in the short to medium term, and the roles that Government, industry, the Environment Agency, local government, business, individuals and transport have in protecting and improving air quality.

2.1.2 Air Quality Standards and Objectives

The UKAQS contains air quality objectives based on the protection of both human health and vegetation (ecosystems) and have been set taking into account the air quality standards defined in the Air Quality Standards Regulations 2007, now superseded by the 2010 (Statutory Instrument 2010 No. 1001, 11th June 2010).

The 2010 Regulations are in turn are defined by ‘limit values’ contained in the following Directives:

 Directive 2008/50/EC of the European Parliament and of the Council on ambient air quality and cleaner air for Europe; and  Directive 2004/107/EC of the European Parliament and of the Council relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air.

A summary of the air quality standards for the pollutants detailed in the UKAQS 2007 for the purpose of Local Air Quality Management is provided in Table 2-1 below.

Table 2-1 UKAQS Air Quality Standards (Human Health)

Pollutant Concentration Measured as 3 Benzene (C6H6) 5 µg/m Annual mean (England and Wales) 1,3-butadiene 2.25 µg/m3 Running annual mean Carbon monoxide (CO) 10 mg/m3 Running 8 hour mean Lead (Pb) 0.25 µg/m3 Annual mean

3 1 hour mean (18 exceedences per year 200 µg/m Nitrogen dioxide (NO2) 99.79%ile of hourly averages) 40 µg/m3 Annual mean

3 15 minute mean (35 exceedences per year; 266 µg/m Sulphur dioxide (SO2) 99.90%ile of 15-min averages) 3 350 µg/m 1 hour mean (24 exceedences per year;

1 The Air Quality Strategy for England, Scotland, Wales and Northern Ireland, DEFRA. July 2007

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Pollutant Concentration Measured as 99.73%ile of hourly averages)

3 24 hour mean (3 exceedences per year; 125 µg/m 99.18%ile of 24-hr averages) 40 µg/m3 Annual mean Particulate matter 3 24 hour mean (35 exceedences per year; (PM10) (gravimetric) 50 µg/m 90.41%ile of 24-hr averages) Particulate matter 25 µg/m3 Annual mean (PM2.5) (gravimetric)

The UKAQS includes more exacting objectives for some pollutants than those required by EC legislation. This air quality assessment refers only to UK Air Quality Standards, as compliance with these standards will also ensure that the less demanding European Air Quality limit values would also be met.

In addition to these UKAQS objectives, the following additional ‘target values’ are defined within the Air Quality Standard Regulations 2010, and 4th EU Daughter Directive:

Table 2-2 Additional Air Quality ‘Target Values’

Pollutant Concentration Measured as Target date Arsenic (As) 6 g/m3 3 Cadmium (Cd) 5 g/m Annual average in PM10 fraction 31.12.2012 Nickel (Ni) 20 g/m3

These ‘target values’ are different from the ‘limit values’ set for other pollutants in that they are not intended to be considered as ‘Environmental Quality Standards’ (EQSs) and have therefore not been applied in this assessment.

2.1.3 Local Authority Air Quality Review and Assessment

The LAQM regime was established under the Environment Act 1995 and the Environment (Northern Ireland) Order 2002. It falls into two distinct parts:

 the review and assessment of air quality within the local authority area; and  the development and implementation of action plans to tackle local air pollution.

Local action planning comes into play only in areas where review and assessment has revealed problematic pollution levels, and in consequence a local Air Quality Management Area (AQMA) has been declared.

Data provided by the UK Air Quality Archive website indicates that, as of April 2010, 237 Local Authorities had declared AQMA’s for one or more pollutants. Road transport is the largest single source of air pollution, accounting for 33% of emissions in the case of NOx and 21% in the case of PM10. Transport is identified as the main source of pollution in 92% of all AQMAs2.

2 IHPC (2010) Review of Local Air Quality Management - A report to Defra and the devolved administrations

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DEFRA Technical guidance document LAQM TG (09) is designed to support local authorities in carrying out their duties under the Environment Act 1995 and subsequent Regulations. It sets out the general approach to be used, together with detailed technical guidance, which is provided on a pollutant by pollutant basis.

2.2 Environmental Permitting Regulations

The Environmental Permitting (England and Wales) Regulations 2010 replaced the Environmental Permitting (England and Wales) Regulations 2007 (SI 2007 No, 3538) on 6th April 2010 and transpose the Waste Incineration Directive, 2000/76/EC (WID) in UK legislation. The Directive applies to incineration and co-incineration plants which burn waste as defined in the Waste Framework Directive. Such wastes include municipal waste, clinical waste, hazardous waste, general waste and waste derived fuels. The Directive applies to the proposed operation.

The WID defines items such as:

 operating conditions, including gas temperatures and residence times, such as 850ºC / 2 seconds;  emission limit values for a range of substance to air and water; and  emission monitoring requirements.

It is likely that, by the proposed commissioning date of 2014, the WID will have been superseded by The Industrial Emissions Directive (IED). This Directive is intended to recast 7 existing Directives (including the WID and IPPC Directives) into one single Directive. The IED is currently undergoing consultation and is therefore not available in final form. Indications are that the proposed entry into force of the new Directive would be 1st January 2011.

2.2.1 Monitoring Requirements

In addition to the monitoring of process parameters such as temperature within the combustion chamber and the oxygen concentration, temperature, moisture and pressure of flue gases; the WID prescribes that continuous monitoring of emissions to air for NOx, TOC, SO2 and HCl and HF are to be undertaken. Although the requirement for continuous monitoring of HF may be omitted if treatment stages are applied which ensure that the emission limit for HCl is not exceeded; because the abatement of HCl to below the WID emission limits would also ensure the abatement of HF to below the WID limits.

Furthermore at least two measurements per year of metals, dioxins and furans, dioxin like PCBs and PAHs is required by the WID. Whilst dioxins and furans are specifically regulated under the WID, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are not specifically regulated under the WID but are effectively controlled through the process conditions and limitation of TOC emissions.

2.2.2 Emission Limit Values to Air

The WID sets out emission limit values for emissions to air as detailed in Table 2-3. These emission limits would be set as Environmental Permit conditions by the Environment Agency as part of the permitting process.

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Table 2-3 WID Emission Limit Values

Emission Limits (mg/Nm3) (a) Half hourly averages Pollutant Daily average values 100th Percentile 97th Percentile Continuous Monitoring Particles 10 30 10 TOC 10 20 10 HCl 10 60 10 HF 1 4 2

SO2 50 200 50 NOx 200 400 200 CO(b) 50 150 100 Spot sample measurements Group 1 metals 0.05 Group 2 metals 0.05 Group 3 metals 0.5 Dioxins and furans(c) 0.0000001 Notes: (a) Concentrations referenced to temperature 273 K, pressure 101.3 kPa, 11% oxygen, dry gas. (b) 150 mg/Nm3 of combustion gas for at least 95% of all measurements determined as 10 minute averages or 100 mg/Nm3 of combustion gas of all measurements determined as half-hourly average values taken in any 24 hour period. (c) The emission limit value refers to the total concentration of dioxins and furans calculated using the concept of toxic equivalence (TEQ).

Metal groups are as follows:

 Group 1: Cadmium (Cd) and thallium (Tl)  Group 2: Mercury (Hg)  Group 3: Antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), and vanadium (V).

2.2.3 ERF Design and Operating Principles

In order to ensure the facility complies with the requirements of the WID, the facility will be designed to operate with emissions to air below the WID emission limits.

In order to achieve this level of performance the proposed Kingswood ERF will include a number of measures. This includes design of the combustion chamber; cooling of flue gas to minimise re-formation of organic compounds and extensive flue gas treatment (FGT). The FGT includes the injection of ammonia to reduce emissions of nitrogen oxides (NOx), injection of lime to reduce acidic gases (such as sulphur dioxide (SO2)) and activated carbon to capture metals and organic compounds. Finally the airstream is filtered (using bag filter systems) to remove particulate matter.

During operation, if the emissions to air begin to approach the WID limits, action will be taken to reduce emissions. This action includes measures such as automatic adjustment of reagent dosing rates (in the FGT) or balancing of the combustion chamber (i.e. increase or decreased combustion airflow).

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If the emissions to air exceed the daily average WID emission limits, the facility will automatically cease the input of waste in accordance with Article 6(3) of the WID.

2.3 Regulation of Industrial Processes

Industrial process emissions to air, such as those from the ERF are controlled under the Environmental Permitting (England and Wales) Regulations 2010. Guidance Notes produced by DEFRA to provide a framework for regulation of installations and additional Technical Guidance Notes produced by the Environment Agency are used to provide the basis for permit conditions regards releases to air and mitigation measures. The proposed ERF facility would be classed as a Part A(i) process under these regulations, amongst other conditions of operation would be emission limits for various pollutants produced by the process, which must be demonstrated through various monitoring requirements as prescribed by the Waste Incineration Directive (WID). The relevant Sector Guidance Note is EPR5.013.

Of particular relevance to the assessment of air quality impacts is the guidance document EPR H1 Annex F4. The purpose of this guidance note is to provide supplementary information, relevant to all sectors, to assist applicants in responding to the requirements described in the EPR Sector and General Guidance Notes. The H1 assessment can be used to support an Environmental Assessment of the overall impact of the emissions resulting from the installation to confirm that the emissions are acceptable (i.e. do not cause significant pollution). The H1 guidance provides the assessor with Environmental Assessment Levels (EALs) for each pollutant against which impact may be assessed.

2.3.1 Environmental Assessment Levels (EAL)

The EALs used in this assessment have been reproduced from EPR Guidance H15, which are based upon the air quality standards and occupational exposure limits (OEL) and maximum exposure levels (MEL) presented in HSE EH406. A summary of the appropriate EALs for pollutants emitted by the proposed facility are included in Table 2-4. EALs have been applied in this assessment where no air quality standard exists, or where the EAL is lower than the corresponding air quality standard.

Table 2-4 Relevant EALs (µg/m3)

Long Term EAL (Annual Short Term (Hourly Pollutant average) average) EAL

Nitrogen dioxide (NO2) 40 200 (a) Particulates (PM10) 40 50 Carbon monoxide (CO) --- 10000(b)

Sulphur dioxide (SO2) --- 267 (15-min)

Sulphur dioxide (SO2) --- 350 (1-hour)

Sulphur dioxide (SO2) --- 125 (24-hour) Hydrogen chloride (HCl) --- 750 Hydrogen fluoride (HF) 16 160 Benzene (surrogate for TOC) 5 208

3 How to comply with your environmental permit - Additional guidance for The Incineration of Waste, EPR 5.01. Environment Agency, March 2009. 4 Horizontal Guidance Note H1 - Annex (f) Air Emissions. v2.1 April 2010. 5 Horizontal Guidance Note H1 - Annex (f) Air Emissions. v2.1 April 2010. 6 HSE (2005) EH40/2005 Workplace Exposure Limits.

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Long Term EAL (Annual Short Term (Hourly Pollutant average) average) EAL Arsenic (As) 0.003 --- Antimony (Sb) 5 150 Cadmium (Cd) 0.005 --- Chromium (II and III) 5 150 (Cr) Chromium (VI) 0.0002 --- Cobalt (Co) ------Copper (Cu) 10 200 Lead (Pb) 0.25 --- Manganese (Mn) 150 1500 Mercury (Hg) 0.25 7.5 Nickel (Ni) 0.02 --- Thallium (Tl) ------Vanadium (V) 5 1 (24-hour) Table Note: a) The Air Quality Limit Regulations 2010 also include an annual average objective of 25µg/m3 for PM2.5. b) Horizontal Guidance Note H1 Table B5 indicates a short term EAL of 30000. The Air Quality Limit Regulations 8-hour limit has instead been used in this assessment.

It can be seen that, although there are WID emission limits for Cobalt, and Thallium there are no EAL’s specified in the H1 guidance for these pollutants. For other pollutants such as Nickel, Lead and Chromium VI, only long term limits are provided in the H1 guidance.

2.3.2 EALs for the protection of Ecosystems and Vegetation

In addition to the critical levels defined in the AQS for NOx and SO2 the following EALs for the protection of ecosystems and vegetation are also defined in H1 as critical levels:

Table 2-5 Critical Levels For The Protection Of Vegetation And Ecosystems

Concentration 3 Habitats Pollutant (µg/m ) Sensitive lichen communities & bryophytes and 1 ecosystems where lichens & bryophytes are an important Ammonia part of the ecosystem’s integrity 3 For all higher plants (all other ecosystems) Sensitive lichen communities & bryophytes and 10 ecosystems where lichens & bryophytes are an important Sulphur dioxide part of the ecosystem’s integrity 20 For all higher plants (all other ecosystems) Nitrogen Oxides 30 All ecosystems Hydrogen Fluoride 5 Daily Mean.

2.4 Impacts on Sensitive Ecosystems

2.4.1 The Conservation of Habitats and Species Regulations (2010)

The Conservation of Habitats and Species Regulations 2010 (‘Habitats Regulations’) transpose Council Directive 79/409/EEC on the conservation of wild birds (‘Birds Directive’)

SLR Biffa Waste Services Limited 8 402.0034.00320 Kingswood ERF: Technical Appendix 6/1 July 2010 and Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (‘Habitats Directive’) into national law (in conjunction with the Wildlife and Countryside Act, see below). The 2010 Regulations replace the Conservation (Natural Habitats, &c.) Regulations 1994.

Regulation 61 (1) states that:

A competent authority, before deciding to undertake, or give any consent, permission or other authorisation for, a plan or project which

(a) is likely to have a significant effect on a European site or a European offshore marine site (either alone or in combination with other plans or projects), and

(b) is not directly connected with or necessary to the management of that site,

must make an appropriate assessment of the implications for that site in view of that site’s conservation objectives.

(2) A person applying for any such consent, permission or other authorisation must provide such information as the competent authority may reasonably require for the purposes of the assessment or to enable them to determine whether an appropriate assessment is required.

Assessment of Air Quality under the Habitats Regulations

In order to clarify the procedure for assessing the impact of industrial facilities regulated by the Environment Agency on designated sites; the Environment Agency has prepared Operational Instructions. These operational instructions form Appendix 77 of the Agency’s guidance (the EU Habitats and Birds Directive Handbook) on how the Agency implements the Habitats Regulations when they consider new consents and review old consents. They define a 4-stage assessment procedure as detailed below:

 Stage1 – identification of relevant application by distance from designated site;  Stage 2 – identification of permissions that are likely to be significant;  Stage 3 – the ‘appropriate assessment’; and  Stage 4 – determination of the permission.

Horizontal Guidance Note: EPRH1 states that conservation sites need only be considered where they fall within set distances of the activity8:

 Special Protection Areas (SPAs), Special Areas of Conservation (SACs) or Ramsar sites within 10km of the installation (or 15km coal- or oil-fired power station);  Sites of Special Scientific Interest (SSSIs) within 5 km of the installation;  National Nature Reserves (NNRs), Local Nature Reserves (LNRs), local wildlife sites and ancient woodland within 2km of the location of the installation.

As part of the ‘stage 2’ assessment, the significance of the long-term process contribution (PC) is assessed against the following criteria:

7 Appendix 7, Assessment of new PIR permissions under the Habitat Regulations, Operational Instruction. Environment agency, Version 2, 06/06/07. 8 Horizontal Guidance Note H1 - Annex (f)

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 If the PC is less than 1% of the relevant long-term benchmark (EAL, critical level or critical load), the emission is ‘not likely to have a significant effect alone or in combination irrespective of the background levels’

Where this criterion is exceeded; consideration of the predicted environmental concentration (PEC) is required and the following criteria applied:

 If the PEC is less than 70% of the relevant long-term benchmark, the emission is ‘not likely to have a significant effect’.

If on the basis of this Stage 2 assessment it cannot be concluded that the emission is not likely to have a significant effect, a Stage 3 ‘appropriate assessment’ is required.

Where it is identified that a Stage 3 ‘appropriate assessment’ is required in relation to emissions to air, the results of detailed atmospheric dispersion modelling are used to predict impacts of various pollutants at the sensitive locations. The procedure for undertaking such an ‘appropriate assessment’ has been defined by the Agency in conjunction with Natural England in the AQTAG069 guidance document.

The AQTAG06 procedure defines the dispersion modelling approach in terms of receptor location and arrays, use of topographical and terrain data, the calculation of deposition fluxes, how these should be considered alongside the background conditions and relevant critical levels and loads.

Once the assessment is complete it should be sufficient to enable a competent authority to make an appropriate assessment of the implications for that site in view of that site’s conservation objectives

2.4.2 Wildlife and Countryside Act

The Wildlife and Countryside Act 1981 (as amended) is the principal mechanism for the legislative protection of wildlife in Great Britain. This legislation is the means by which the Convention on the Conservation of European Wildlife and Natural Habitats (the 'Bern Convention') and the European Union Directives on the Conservation of Wild Birds (79/409/EEC) and Natural Habitats and Wild Fauna and Flora (92/43/FFC) are implemented in Great Britain.

Planning authorities are required to consult Natural England (NE) before granting planning permission for the development of land in a Site of Special Scientific Interest (SSSI), or within the consultation area around a SSSI, as defined by NE.

The planning authority is also required to consult NE if the development is considered likely to affect a SSSI, even if the application site falls outside the SSSI and surrounding consultation area.

9 AQTAG06 – Technical Guidance on detailed modelling approach for an appropriate assessment for emissions to air. Environment Agency, working Draft version 10, May 2010.

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3.0 ASSESSMENT METHODOLOGY

3.1 Dispersion Modelling

Detailed atmospheric dispersion modelling has been undertaken with due consideration to relevant guidance10,11 and the modelling approach is based upon the following stages:

 identification of sensitive receptors;  review of emissions from other existing and proposed local industrial sources;  review of process design proposals and emission sources;  compilation of the existing air quality baseline with due regard to Review and Assessments of local air quality;  calculation of process contribution to ground level concentrations and deposition for key pollutants emitted from the process;  evaluation of effects on ecological receptors;  consideration of cumulative effects; and  sensitivity analyses of model input data.

A number of commercially available dispersion models are able to predict ground level concentrations arising from emissions to atmosphere from elevated point sources such as the Kingswood ERF. No dispersion model is wholly accurate and all models will produce variations in results under certain conditions. For this assessment the AERMOD Pro model12 has been used.

The AERMOD dispersion modelling program is widely used and accepted by the Environment Agency in the UK for undertaking such assessments and its predictions have been validated against real-time monitoring data by the USEPA13. It is therefore considered a suitable model for this assessment.

3.1.1 Combined Effects with Existing Air Pollution Sources

There are other sources of air pollution within 2km of the application site. Predominately these are associated with traffic, domestic and small industrial sources and their contribution will be included in the background air quality data applied.

There are however potential cumulative impacts associated with:

 operation of the proposed Four Ashes EfW; and  the existing Poplars landfill gas engines; and  the proposed 120000t/a AD facility proposed on the site.

10 Air Dispersion modelling report requirements (for detailed air dispersion modelling). AQMAU, Environment Agency (not dated). 11 Guidelines for the Preparation of Dispersion Modelling Assessment for Compliance with Regulatory Requirements – an update to the 1995 Royal Meteorological Society guidance. UK Atmospheric Dispersion Modelling Committee (ADMLC), Version 1.4, 2004. 12 Software used: BREEZE AERMOD GIS Pro, v7.0. 13 AERMOD: Latest Features and Evaluation Results. USEPA Report: EPA-454/R-03-003 June 2003, (http://www.epa.gov/scram001/dispersion_prefrec.htm#aermod)

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Whilst the impact of the existing landfill gas engines will be contained within the existing background levels applied in the assessment, the other facilities are not yet operational. Therefore assessment of the cumulative impacts associated with the potential sources above are addressed in Section 8.0 of this report.

3.1.2 Deposition Modelling – Metals and dioxins

In order to inform the assessment of potential impacts on human health, the air dispersion model has been interrogated to provide deposition rates of relevant metals and dioxins. Full details are presented in the human health risk assessment (HHRA).

3.2 Assessment of Impacts on Human Receptors

The predicted ground level concentration of the modelled pollutants have been compared as a Process Contribution (PC) and Predicted Environmental Concentration (PEC; PC plus existing background pollutant concentration) and presented as a percentage of the relevant air quality standard or EAL.

3.3 Assessment of Impacts on Vegetation and Ecosystems

3.3.1 Critical Levels

Critical levels are a quantitative estimate of exposure to one or more airborne pollutants in gaseous form, below which significant harmful effects on sensitive elements of the environment do not occur, according to present knowledge. Critical levels for the protection of vegetation and ecosystems are specified within relevant European air quality directives and corresponding UK air quality regulations.

For all European sites, SSSIs and other ecological sites in the study area, process contributions (and predicted environmental concentrations where required) of NOx , NH3, HF, and SO2 have been calculated for comparison against critical level thresholds.

3.3.2 Critical Loads

Critical loads are a quantitative estimate of exposure to deposition of one or more pollutants, below which significant harmful effects on sensitive elements of the environment do not occur, according to present knowledge.

Critical loads are set for the deposition of various substances to sensitive ecosystems. Predicted contributions to acid deposition and nitrogen deposition have been calculated and compared with the relevant critical load range for the habitat types associated with each designated site as derived from the UK Air Pollution Information System (APIS) website (www.apis.ac.uk/).

Deposition rates were calculated using dispersion modelling results processed by following empirical methods recommended by the Environment Agency in AQTAG06 and summarised in the following sections

3.3.3 Calculation of Contribution to Critical Loads

Deposition rates were calculated using empirical methods recommended by the Environment Agency (AQTAG06), as described below.

Calculate dry deposition flux using the following equation:

Dry deposition flux (μg/m2/s) = ground level concentration (μg/m3) x deposition velocity (m/s)

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The applied deposition velocities for various chemical species are as shown in Table 3-1.

Table 3-1 Applied Deposition Velocities

Chemical Species Recommended deposition velocity (m/s)

NO2 Grassland 0.0015 Woodland 0.003

SO2 Grassland 0.012 Woodland 0.024

NH3 Grassland 0.02 Woodland 0.03 HCl Grassland 0.025 Woodland 0.06

2 The units are then converted from μg/m /s to units of kg/ha/year by multiplying the dry deposition flux by standard conversion factors as summarised in Table 3-2.

Table 3-2 Applied Deposition Conversion Factors

Chemical Species Conversion factor [µg/m2/s to kg/ha/year]

NO2 of N: 96

SO2 of S: 157.7

NH3 of N: 259.7 HCl of Cl: 306.7

Wet deposition occurs via the incorporation of the pollutant into water droplets which are then removed in rain or snow, and is not considered significant over short distances (AQTAG06) compared with dry deposition and therefore for the purposes of this assessment, wet deposition has not been considered.

Critical Loads - Eutrophication

The contribution to critical loads for Nitrogen deposition are recorded as KgN/ha/yr.

Critical Loads - Acidification

The predicted deposition rates are converted to units of equivalents (keq/ha/year), which is a measure of how acidifying the chemical species can be, by dividing the dry deposition flux (kg/ha/year) by standard conversion factors as presented in Table 3-3.

Table 3-3 Applied Acidification Conversion Factors

Chemical Species Conversion factor [kg/ha/year to keq/ha/year] of N: divide by 14 of S: divide by 16 of Cl: divide by 35.5

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The predicted dry N, S and Cl deposition (keq/ha/year) are summed to determine total acid deposition.

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4.0 BASELINE ENVIRONMENT

4.1 Site Location

The application site is located within the Kingswood Lakeside Business Park, approximately 2 km south east of Cannock town centre. The application site is north of the M6 Toll Road to the north is the existing Poplars landfill site. To the south of the M6 is the A5 and residential development.

The site is mostly cleared land but there is some vegetation around the edges of the site and more mature trees around the lake in the east of the site. To the west, over the A34 Walsall Road is mixed residential and industrial development.

There are also a number of sensitive habitats and protected sites within a 10km radius of the application site. These include the Cannock Chase SAC, for example.

4.2 Existing Local Sources

Air quality information obtained from the UK National Atmospheric Emissions Inventory (NAEI) (www.naei.org.uk) includes the contribution of key sectors to annual average total emissions within the UK. Data for the 1km grid square containing the proposed development (OS GR 399500, 308500) presented in Table 4-1 demonstrates the significance of the existing transport and industrial sources. This data relates to the year 2007, which represents the most recent available at the present time.

Table 4-1 Existing Local Emissions within surrounding 1km grid squares of the Proposed Development (2007)

Category NOx (t/yr) PM10 (t/yr) SO2 (t/yr) VOC (t/yr) Energy Production and Transformation 0.000 0.000 0.000 0.000 Commercial, Institutional and Residential Combustion 0.323 0.118 0.209 0.276 Industrial Combustion 0.000 0.000 0.000 0.000 Industrial Processes 0.000 0.001 0.000 0.211 Production and Distribution of Fossil Fuels 0.000 0.000 0.000 0.008 Solvent Use 0.000 0.000 0.000 0.191 Road Transport 14.500 0.878 0.079 1.650 Other Transport 0.288 0.028 0.023 0.059 Waste Treatment and Disposal 0.002 0.024 0.000 0.025 Agriculture 0.000 0.002 0.000 0.000 Nature 0.000 0.003 0.000 0.021

There is a coal fired power station at Rugeley, however this is over 10km from the application site.

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4.3 Local Air Quality Management

The site falls within the administrative area of Cannock Chase District Council (CCDC).Cannock Chase District extends from a southern boundary with the Walsall Metropolitan Borough Council (WMBC) to a northern boundary along the River Trent. At the two ends of the district are the towns of Cannock and Rugeley with large tracts of wooded and heath areas of Cannock Chase between the two urban areas.

Industrial land use is concentrated on the peripheries of the urban areas, to the north and east of Rugeley, north-east of Cannock town centre, along the A5 corridor and south of Norton Canes.

The main arterial roads consist of:

 A5 Watling Street, running south east to north westerly across the southern section of the district;  A460 & A4601, running south west to north east through Cannock to Rugeley, crossing Cannock Chase AONB;  A34, running south to north through Cannock;  A51, running east to west through Rugeley; and  A5190, running easterly from Cannock.

CCDC has carried out regular Review and Assessment in accordance with its statutory obligations. One AQMA has been declared. The area encompasses the A5 Watling Street between the junction with the A34 Walsall Road and the district boundary with South Staffordshire, and the stretch of the A460 Wolverhampton Road between the junction with the A5 Watling Street and the district boundary. This AQMA is less than 1km from the site boundary (to the west). Figure 4-1 Watling Street, Bridgtown AQMA

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4.4 Background Levels and Predictions

This section reviews the existing baseline air quality in the region of the application site undertaken by local authorities and DEFRA as part of LAQM obligations and additional monitoring undertaken by SLR Consulting for the purposes of this assessment.

4.4.1 Cannock Chase District Council

Automatic Monitoring Data

Cannock Chase DC operates two automatic analysers, at Watling Street, Bridgtown and Bettys Lane, Norton Canes. Data is shown below14

Table 4-2 Automatic Monitoring Data: Annual Mean (µg/m3)

Bridgtown Norton Canes Pollutant 2009 2008 2007 2009 2008 2007 (Annual (Annual (Annual (Annual (Annual (Annual Mean) Mean) Mean) Mean) Mean) Mean)

NO2 42.8 49.1 39.8 20.8 27.7 29.9

PM10 16.8 19.5 22.4 10.5 13.4 12.9

Non-automatic monitoring data

In 2009 Cannock Chase District council monitored nitrogen dioxide using diffusion tube techniques at the locations shown below.

Table 4-3 Automatic Monitoring Data: Annual Mean (µg/m3)

Annual Annual Annual Location Situation Mean Mean Mean (2007) (2008) (2009) Mayflower Drive Urban Background 14.0 17.7 17.0 Rugeley Hislop Drive Urban Background 14.3 18.1 17.6 Forestry Commission Rural Background 10.5 12.1 - BTL Roadside 38.8 53.1 54.6 BTL-B Roadside AQMA 37.7 38.5 42.9 BTL-M Roadside AQMA 34.1 36.8(a) - BTL-A Roadside AQMA 37.8 41.4(a) - Bridgtown 67WS Watling street Roadside AQMA - 29.3(b) 30.4 54WS Watling street Roadside AQMA - 35.79b) 43.0 268WS Watling street Unknown - - 38.4(c ) Co-location (BTMS) Roadside AQMA - 48.8 - Cannock, Oxford Rd Urban Background 19.6 28.4 25.1 Hednesford Mortuary, Beech Tree Urban Background 16.2 21.5 & Heath Lane 21.4

14 Data taken from http://www.air-quality.net/

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Annual Annual Annual Location Situation Mean Mean Mean (2007) (2008) (2009) Hayes Attingham Drive Kerbside 14.4 19.8 20.7(d) Pye Green Rd Kerbside 28.4 41.0 - Deavalls Farm Unknown - - 19.3(e) Norton Canes High Urban Background 15.0 24.4 School 18.7 Betty Lanes, Norton Norton Canes Co-location Suburban 19.7 24.3 Canes (BLNC) 22.7 Off Walsall Rd, Norton Special/Roadside 24.8 29.0 Canes (WRNC) - (a)Partial year results for 2008. Sampled from January to July. (b) Partial years results for 2008. Sampled from September to December (c) Partial year results:sampled from August 2009 (d) 4 Month average with months Jan, Feb, March, May. (e) Partial year results: sampled from June 2009

Monitoring locations for 2009 represent background and roadside locations and vary between annual mean concentrations of 17.0µg/m3 and 54.6µg/m3.

4.4.2 National Air Quality Archive

Background pollutant concentrations have been obtained from the National Air Quality Archive UK Background Air Pollution Maps. These 1km grid resolution maps are derived from historic background annual mean pollutant concentrations which are then projected to future years.

The estimated annual mean background concentrations for the grid squares containing the application site (399500, 308500) and landfill (399500, 309500) have been averaged and are shown below for pollutants relevant to this assessment.

Table 4-4 Predicted Annual Mean Background Concentrations

Pollutant Predicted 2010 (µg/m3) Predicted 2013 (µg/m3) Predicted 2014 (µg/m3)

NO2 20.84 18.88 18.22

NOx 27.45 24.95 23.90

PM10 16.71 19.25 19.10

PM2.5 11.24 12.31 12.21 CO 179 163 160 Benzene 0.45 0.44 0.43

4.4.3 Heavy Metals

Monitoring of metals is currently carried out by Defra at 27 sites around the UK (17 as part the UK Heavy Metals Monitoring Network and 10 as part of the Rural Heavy Metals and Mercury Network).

The closest station to the application site is Walsall Centre (part of the Urban Heavy Metals and Mercury Network) located approximately 11km to the southwest of the application site.

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This monitors Arsenic, Cadmium, Chromium, Copper, Iron, Manganese, Nickel, Lead, Platinum, Vanadium, Zinc and Mercury.

Table 4-5 Heavy Metals Monitoring Data Walsall Centre (annual average g/m3)

Metal 2008 2009 Average Arsenic 1.0 1.1 1.0 Cadmium 0.5 0.5 0.5 Chromium 1.5 2.5 2.0 Copper 15.7 16.3 16.0 Manganese 9.0 9.1 9.1 Nickel 1.5 0.8 1.1 Lead 19.3 19.0 19.2 Vanadium 1.3 1.4 1.4 Mercury (vapour) 4.3 4.5 4.4

Monitoring is not routinely undertaken for thallium, antimony and cobalt in the UK and therefore no background data are available.

4.4.4 Hydrogen Halides

Hydrogen Chloride

Hydrogen chloride is monitored as part of the nitric acid network (now part of the acid deposition monitoring network). The nitric acid network was established in 1999 with twelve rural sites and has now expanded to 30 around the UK. The mean concentration of HCl during the period 2007 – 2008 was 0.31µg/m3 for the Sutton Bonington monitoring station.

Table 4-6 Annual Mean Concentrations of HCl (µg/m3) at Sutton Bonington

Site 2007 2008 Mean 2007 to 2008 Sutton Bonington 0.35 0.29 0.31

Hydrogen Fluoride

In 2005 The Expert Panel on Air Quality Standards (EPAQS) published a draft report entitled 'Guidelines for halogen and hydrogen halides in ambient air for protecting human health against acute irritancy effects’. The report noted that only a small number of measurements of ambient concentrations of hydrogen fluoride have been made in the UK. All of these have been made in the vicinity of three industrial plants. Many samples were below the limit of detection. However, measurable values were in the range 5x10-5 to 3.5x10-3 mg/m3 as approximate monthly averages.

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4.5 Baseline Monitoring

During July 2009 SLR commenced a diffusion tube survey to quantify the current air quality in the area surrounding the proposed Kingswood site. Diffusion tubes were deployed in line 15 with the NO2 Diffusion Tube Network schedule set by NETCEN . The year is divided into 12 pollution 'months', each consisting of 4 or 5 whole weeks.

Table 4-7 shows the relevant monitoring schedule dates for the SLR diffusion tube survey.

Table 4-7 Monitoring Calendar for Year 2009

NETCEN Period Start Date End Date Duration (weeks) 7 01/07/2009 29/07/2009 4 8 29/07/2009 02/09/2009 5 9 02/09/2009 30/09/2009 4 10 30/09/2009 04/11/2009 5 11 04/11/2009 02/12/2009 4 12 02/12/2009 06/01/2010 5

Diffusion tubes were situated in nearby areas, including Cannock, Norton Canes and Prospect Village. The pollutants which were monitored are nitrogen dioxide (NO2), hydrogen chloride (HCl), hydrogen fluoride (HF), sulphur dioxide (SO2) nitrogen oxides (NOx) and VOCs.

The locations of the diffusion tubes are presented in Table 4-8 below and Drawing 01.

Table 4-8 Location of Diffusion Tubes for Baseline Assessment

Location Distance Direction from Stack from stack Pollutants Monitored Ref. Setting OSGR (m) (m) (deg)

KW 1 Roadside 397361, 308865 2159 278 NO2, NOx Co-location in KW 2 398011, 308568 1487 270 NO Bridgtown 2

KW 3 Residential 398860, 308153 756 237 NO2

KW 4 Roadside 399590, 307873 693 172 NO2, NOx

KW 5 Residential 402366, 308877 2886 84 NO2, SO2, HCl, HF

KW 6 Residential 400633, 311618 3262 20 NO2

KW 7 Roadside 400883, 310021 2013 43 NO2

KW 8 Residential 400035, 310072 1605 20 NO2, SO2, HCl, HF, VOC

KW 9 Roadside 399314, 309833 1286 352 NO2, SO2, HCl, HF, VOC

KW 10 Roadside 398916, 309131 815 314 NO2

KW 11 Suburban 400046, 308947 671 55 NO2, SO2, HCl, HF

KW 12 Residential 401358, 308066 1925 105 NO2, SO2, HCl, HF, VOC

15 UK National Air Quality Archive, NETCEN, www.airquality.co.uk

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Location Distance Direction from Stack from stack Pollutants Monitored Ref. Setting OSGR (m) (m) (deg)

KW 13 Residential 398743, 309482 1192 321 NO2, SO2, HCl, HF, VOC

KW 14 Background 400252, 314901 6386 7 NO2, SO2, HCl, HF, VOC Note: Stack location taken as OS GR 399497.8, 308559.7

4.5.1 Baseline Monitoring Results

The results of the diffusion tube monitoring are presented in Table 4-9 below. Results have been bias and period/annual mean adjusted in accordance with DEFRA Guidance LAQM TG(09). The results are presented as an average over the sampling period. Locations are shown in Drawing 01.

Table 4-9 3 NO2 Diffusion Tube Monitoring Results (µg/m )

NO (Annual / Diffusion Tube Number of NO (Bias 2 NO (Raw Data) 2 Period Mean Location months data 2 Adjusted) Adjusted) 1 6 41.3 33.5 33.12 2 6 47.8 38.7 38.33 3 6 32.4 26.3 26.01 4 6 58.8 47.6 47.14 5 6 22.5 18.2 18.02 6 4 26.4 21.4 21.15 7 5 32.3 26.1 25.89 8 6 23.3 18.9 18.72 9 6 48.0 38.9 38.51 10 6 56.7 45.9 45.44 11 6 31.8 25.8 25.53 12 5 27.5 22.2 22.02 13 4 29.6 24.0 23.73 14 5 16.1 13.0 12.88 Notes: Tube location 2 co-located with Watling Street real-time monitor. Bias adjustment factor of 0.81 applied from co-location adjustment, with annual-period mean factor of 0.99.

The monitoring results for the other pollutants are shown below.

Table 4-10 Baseline Diffusion Tube Monitoring Results (µg/m3)

Diffusion Tube NO SO Benzene HCl HF Location x 2 1 65.5 n/m n/m n/m n/m 4 101.8 n/m n/m n/m n/m 5 n/m 3.6 n/m 1.9

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Diffusion Tube NO SO Benzene HCl HF Location x 2 11 n/m 2.3 n/m 1.1

4.6 Summary of Applied Background Concentrations

Where monitoring data is not available for short term background concentrations they have been calculated from the annual average using a factor of 2 have been applied in this air quality assessment in accordance with EPR H1 Guidance.

Table 4-11 Applied Background Concentrations Background Concentration Pollutant Units Short Term Long Term Data Source 3 NO2 µg/m 36.4 18.2 3 PM10 µg/m 38.2 19.1 3 Air Quality Archive (2014) PM2.5 µg/m 24.4 12.2 CO µg/m3 1600 160 3 SO2 µg/m 8.2 4.1 SLR Monitoring (average HCl µg/m3 13.2 6.6 of values at location with 3 highest reading) HF µg/m 0.092 0.046 Benzene µg/m3 0.86 0.43 Air Quality Archive 2014 Cadmium ηg/m3 1.0 0.5 Mercury (vapour) ηg/m3 8.8 4.4 3 Rural Heavy Metals Arsenic ηg/m 2.0 1.0 Network (Walsall) Lead ηg/m3 38.4 19.2 Nickel ηg/m3 2.2 1.1 Chromium (total) ηg/m3 4.0 2.0 Chromium VI* ηg/m3 0.20 0.1 Rural Heavy Metals Copper 3 32.0 16.0 ηg/m Network (Walsall) Manganese ηg/m3 18.2 9.1 Vanadium ηg/m3 2.8 1.4 * Chromium VI concentration has been taken as 5% of the total Chromium concentration.

The conversion factor between short term and long term CO of 10 is based on typical observed ratios. For all other pollutants the hourly background has been calculated from the annual average using a factor of 2 as recommended in EPR H1.

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4.7 Sensitive Receptors: Human

The term 'sensitive receptors' includes any persons, locations or systems that may be susceptible to changes as a consequence of the proposed development.

According to the LAQM TG(09), air quality standards should only apply to all locations where members of the public may be reasonably likely to be exposed to air pollution for the duration of the relevant objective. Thus short term standards such as the 1 hour standard for NO2 should apply to footpaths at site boundaries and other areas which may be frequented by the public even for a short period of time. Longer term standards such as the 24 hour for PM10, or annual means, should apply at houses other locations which the public can be expected to occupy on a continuous basis. These standards do not apply to exposure at the workplace.

Dispersion modelling has been completed using a receptor grid and therefore impact concentration may effectively be determined at any location surrounding the site. All results are presented as maximum Ground Level Concentration (GLC).

4.7.1 Receptor Heights

Conventionally dispersion models are utilised to predict ground level impacts of pollutant for comparison with suitable assessment levels. This approach has been adopted for this assessment.

4.8 Sensitive Receptors: Ecological

Horizontal Guidance Note: EPRH1 states that conservation sites need only be considered where they fall within set distances of the activity16:

 Special Protection Areas (SPAs), Special Areas of Conservation (SACs) or Ramsar sites within 10km of the installation (or 15km coal- or oil-fired power station);  Sites of Special Scientific Interest (SSSIs) within 5 km of the installation;  National Nature Reserves (NNRs), Local Nature Reserves (LNRs), local wildlife sites and ancient woodland within 2km of the location of the installation.

The above radii have therefore been applied in this assessment (centred on OS GR399450,308600). Table 4-12 lists the sites of local, national and international ecological value within the zone of influence of the study area.

Table 4-12 Designated Sites within Zone of Influence of the Study Area

Geographical Frame of Site Reference Designation Reference Local No sites ---- Local Nature Reserve Chasewater Heaths 1002649 Site of Special Scientific Interest Stowe Pool and Walk Mill National Clay Pit 1007168 Site of Special Scientific Interest Biddulph's Pool & No Man's 1002469 Site of Special Scientific Interest

16 Horizontal Guidance Note H1 - Annex (f)

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Geographical Frame of Site Reference Designation Reference Bank Cannock Extension Canal 1002085 Site of Special Scientific Interest Cannock Extension Canal UK0012672 Special Area of Conservation International* Cannock Chase UK0030107 Special Area of Conservation *SAC’s often contain multiple SSSI’s. The Cannock Extension Canal for example, consists of 2 SSSIs, only 1 of which is in the 5km radius. Both SSSI’s have however been assessed due to their SAC status (and therefore 10km radius).

In accordance with AQTAG06, discrete receptors have been used to represent those sensitive sites which have been designated on ecological grounds.

4.8.1 Existing Levels

The location of the discrete receptors was then used alongside the citation of the site to obtain the existing critical level of NOx and SO2 and relevant critical loads (and current loads) of nitrogen and acid deposition from the UK Air Pollution Information System (www.apis.ac.uk) as summarised in Table 4-13 below.

APIS provides specific critical load functions for Special Areas of Conservation (SAC’s), in this case the Cannock Extension Canal and Cannock Chase, these are given separately below.

Table 4-13 Existing Levels of Deposition at Ecological Receptors (source: APIS) Acid Deposition Nitrogen Deposition (keq/ha/yr) (kgN/ha/year) Ref Feature Critical Current Critical Current Load Load Load Load

None None ER1 Chasewater Heaths 10-25* 22.5 available available Stowe Pool and Walk Mill None None ER2 2.2 23.9 Clay Pit available available Biddulph's Pool & No Man's None None ER3 10-25* 22.5 Bank available available Note: Where habitat designations are not detailed on the APIS resource, the most suitable APIS designation has been applied. Current levels of Acid and nitrogen deposition are based on 2003-2005 3-yr average. *UK mapping value 15 (kgN/ha/year)

Cannock Extension Canal

The Cannock Extension Canal SAC contains the following habitat / species of interest (‘Interest Feature’):

 Luronium natans (S1831), Floating water-plantain.

APIS gives the baseline 2010 levels of N and S deposition of:

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 N Deposition: 1.21 keq/ha/yr :: 16.9 kg/ha/yr; and  S Deposition: 0.66 keq/ha/yr :: 10.6 kg/ha/yr

The critical load for eutrophication is 5-10 Kg N/ha/yr based on EUNIS Code C1.1 - Permanent oligotrophic lakes, ponds and pools. Luronium natans is potentially acid sensitive to acidity at oligotrophic sites, however no acidity critical loads are provided.

It can be seen that, at the Cannock Extension Canal, the existing levels of nutrient nitrogen are above the critical load range for Luronium natans when populating oligotrophic sites (such as mountain lakes and streams). JNCC describe this habitat and population as follows:

Cannock Extension Canal in central England is an example of anthropogenic, lowland habitat supporting floating water-plantain Luronium natans at the eastern limit of the plant’s natural distribution in England. A very large population of the species occurs in the Canal, which has a diverse aquatic flora and rich dragonfly fauna, indicative of good water quality. The low volume of boat traffic on this terminal branch of the Wyrley and Essington Canal has allowed open-water plants, including floating water-plantain, to flourish, while depressing the growth of emergents.

Cannock Chase SAC

The Cannock Chase SAC contains the following habitats / species of interest (‘Interest Features’):

 Northern Atlantic wet heaths with Erica tetralix (H4010)  European dry heaths (H4030)

APIS gives the baseline 2010 levels of N and S deposition as follows:

 N Deposition: 0.99 keq/ha/yr :: 13.9 kg/ha/yr  S Deposition: 0.41 keq/ha/yr :: 6.6 kg/ha/yr

The empirical Critical loads for eutrophication for the habitats are as follows:

 Northern Atlantic wet heaths with Erica tetralix: 10-25 Kg N/ha/yr (UK mapping value 15 Kg N/ha/yr);  European dry heaths: 10-20 Kg N/ha/yr (UK mapping value 12 Kg N/ha/yr).

The critical load functions for acidity are identical for the two types of heath, as shown in the table below:

Table 4-14 Critical Load Functions, Cannock Chase SAC

Interest Feature LminN MinC MinCLmaxS MinCLmaxN MaxCLminN MaxCLmaxS MaxCLmaxN

H4010 2.35 1.63 1.64 0.24 1.39 0.71 H4030 2.35 1.63 1.64 0.24 1.39 0.71 Note: A full description of the critical load function terminology can be found at www.apis.ac.uk

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At the Cannock Chase SAC, the existing levels of nutrient nitrogen and acidity are within the critical load range (i.e. above the minimum and below the maximum) for heathland.

4.9 Meteorological Conditions

The most important meteorological parameters governing the atmospheric dispersion of pollutants are as follows:

 wind direction determines the broad transport of the emission and the sector of the compass into which the emission is dispersed;  wind speed will affect ground level concentrations of emissions by increasing the initial dilution of pollutants in the emission; and  Atmospheric stability: is a measure of the turbulence, particularly of the vertical motions present. Advanced dispersion models use Monin-Obukhov lengths - a more advanced method of determining stability17 than Pasquill.

Following consultation with the meteorological data provider, it was concluded that Coleshill located approximately 28km from the application site would provide the most complete and representative dataset for purposes of this assessment. Meteorological data used in this assessment was for the period 1st January 2004 to 31st December 2008 (inclusive).

A windrose for Coleshill for the period 2004 to 2008 (inclusive), providing the frequency of wind speed and direction, is presented in Figure 4-2.

Figure 4-2 Windrose for Coleshill Observing Station (2004 – 2008)

17 Defined as: ‘the height over the ground, where mechanically produced (by vertical shear) turbulence is in balance with the dissipative effect of negative buoyancy, thus where Richardson number equals to 1.’ Essentially it is a more quantitative method of estimating stability than the previously used Pasquill Stability Classes. It requires two quantities not routinely measured by national meteorological networks: the friction velocity u and flux of sensible heat H.

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As is apparent from this windrose, the predominant wind direction is from the south western quarter. There is also a marked easterly component. Wind directions from the north east and south east occur relatively infrequently. The table below shows the percentage of wind speed by direction. It can be seen that the completeness of the data set is acceptable (less than 10% missing data.

Table 4-15 Coleshill Wind Statistics (2004 – 2008)

Dir \ Spd <= 1.54 <= 3.09 <= 5.14 <= 8.23 <= 10.80 > 10.80 Total 0.0 1.7 1.3 2.0 0.6 0.1 0.0 5.8 22.5 1.2 0.9 1.7 0.7 0.1 0.0 4.6 45.0 1.0 0.8 1.8 0.6 0.0 0.0 4.2 67.5 0.9 0.7 0.9 0.3 0.0 0.0 2.8 90.0 0.8 0.7 0.7 0.1 0.0 0.0 2.3 112.5 0.6 0.5 0.7 0.3 0.0 0.0 2.1 135.0 0.7 0.6 1.1 0.3 0.0 0.0 2.7 157.5 1.6 1.7 2.4 0.9 0.1 0.0 6.7 180.0 1.9 2.3 4.6 2.2 0.3 0.0 11.3 202.5 1.2 1.8 5.5 3.8 0.9 0.1 13.4 225.0 1.7 2.4 4.1 1.1 0.1 0.0 9.4 247.5 1.3 1.5 2.6 0.8 0.1 0.0 6.3 270.0 0.8 1.1 2.6 1.5 0.3 0.1 6.3 292.5 0.8 1.4 2.6 0.8 0.1 0.0 5.7 315.0 1.2 1.6 3.6 1.1 0.1 0.0 7.6 337.5 1.2 1.1 2.7 1.1 0.1 0.0 6.3 Total 18.7 20.4 39.6 16.1 2.3 0.3 97.4 Calms 1.0 Missing 1.6 Total 100.0

4.10 Topography

The presence of elevated terrain can significantly affect the dispersion of pollutants and the resulting ground level concentration in a number of ways. Elevated terrain reduces the distance between the plume centre line and the ground level, thereby increasing ground level concentrations. Elevated terrain can also increase turbulence and, hence, plume mixing with the effect of increasing concentrations near to a source and reducing concentrations further away.

The topography of the surrounding area covered by the modelling grid (within a 10km radius) is variable lying between 77m (at 393750m, 316050m) and 237m AOD (at 404500m, 312800m).

Given the elevated receptors to the south and west of the site elevation data has been included in the model although the topographical features are considered unlikely to have a significant effect on the dispersion of emissions from the stack; this has been tested in the sensitivity assessment.

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5.0 QUANTIFICATION OF EMISSIONS TO ATMOSPHERE

5.1 Sources of Emission

The combustion of waste gives rise to emissions of a number of pollutants which are abated to low concentrations which are regulated under the WID. Emissions from the proposed Kingswood ERF facility would be ducted through 2 separate flues of 90m in height.

5.2 Concentration of Emissions

The pollutants emitted from the proposed Kingswood ERF facility and their emission limit values, as stated in the Waste Incineration Directive (WID) are shown in Table 2-3.

In order to predict a realistic ‘worst case’ scenario, the proposed Kingswood ERF facility has been assumed to be in operation continuously throughout the year, and to have pollutant emission rates at the daily average emission limits permitted by the WID. This ensures that the maximum possible long term impacts on air quality are predicted with the facility in operation within its authorisation limits. In reality operational hours would be between 8000 and 8200 per year and emissions significantly below the WID emission limits.

5.2.1 Pollutant Specific Issues

Particulate Matter – Particle Size

In air quality terms particulate matter is classified in terms of its aerodynamic diameter; with PM10 relating to particles with an aerodynamic diameter of less than 10µm. Other smaller relevant fractions of particulate matter such as PM2.5 (aerodynamic diameter less that 2.5µm) are a sub-fraction of the PM10 fraction i.e. PM10 includes PM2.5.

Emissions of dust from the proposed Kingswood ERF would range in particle size, with only a proportion being PM10 or smaller. There is little monitoring data available as to the particle size distribution from any industrial facility; however published literature18 does provide an indication that approximately 50% of particulate matter, from the combustion of MSW using similar technologies, may comprise PM10 with approximately 30% as PM2.5.

The proposed flue gas treatment would utilise a fabric filter (amongst other stages) which published data indicates has high collection efficiencies for a range of particle sizes. For example USEPA guidance for generation of particle size distributions19 indicates a 99% collection efficiency for particle sixes <2.5 µm and 99.5% for particle sizes between 2.5 µm and 10 µm.

For the purposes of this assessment 100% of particulate matter has been assumed to be PM10 and also 100% to be PM2.5. This approach ensures that the absolute worst case scenario has been considered for the smallest particles.

Total Organic Carbon

18AP42, Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1: Stationary Point and Area Sources, Appendix B1. (http://www.epa.gov/ttn/chief/ap42/index.html ) 19 AP42, Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1: Stationary Point and Area Sources, Appendix B.2. (http://www.epa.gov/ttn/chief/ap42/index.html )

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There are no relevant air quality assessment levels or background for Total Organic Carbon. Whilst it is unlikely that any benzene would be released from the process due to the high temperature of combustion a cautious approach has been adopted by assuming all the organic carbon would be in the form of benzene in line with guidance in EPR H1.

Metals

As shown in Table 2-3, the WID emission limits for heavy metals are based on total emission rates for 3 different groups of compounds. The emission rate for Group 1 Metals has been divided by 2 (i.e. each metal at 50% of the WID emission limit for the group). The emission rate for Group 3 Metals has been divided by 9 (i.e. each metal at 11.1% of the WID emission limit for the group). It is not plausible to expect any one metal within that group to account for 100% of the WID limit and typical emissions are described in section 7.3.

Ammonia

The plant would be provided with a non catalytic deNOx system (SNCR). As a result of this abatement of NO2, there is the potential for residual ammonia to be released in small quantities from the stack. The manufacturers have indicated this would be limited to an average of 10mg/m3.

Chromium

In relation to chromium, it is important to note that different EALs apply depending on the oxidation state of chromium. The EPAQS recommended annual mean limit of 0.2ηg/m3 relates specifically to chromium (VI) (i.e. hexavalent chromium), with the long-term EAL of 5µg/m3 applying to all other oxidation states of chromium.

The proportion of Chromium in the hexavalent state (i.e. Chromium VI) in the stack emission from such facilities is difficult to quantify due to the limitation of monitoring techniques and the very low levels present. Recent Environmental Permit decision notices for a similar facilities indicates that preferred Environment Agency approach is to assume that the proportion of total chromium in the hexavalent state in collected APC residues is similar to the distribution in particulate emission from the stack. The Environment Agency data shows that ‘the mean proportion of Cr (VI) to total Cr (in APC residue) is less than 1%. There are two outliers at 2%’. Therefore for the purposes of this assessment, 1% of total chromium has been assumed to be in the hexavalent state.

5.3 Process Conditions

The following process conditions were used to determine the pollutant emission rates and during the dispersion modelling process. The process data has been supplied by the technology provider.

Table 5-1 Emission Characteristics from Stack

Parameter / Source Line 1 Line 2 Stack Location NGR (x,y) 399497.8, 308559.7 399500.0, 308556.2 Stack Diameter (m) 2.15 2.15 Basal Stack Elevation (m AOD) 141.5 141.5 Stack Exhaust Height (m) 90.0 90.0 Volume Flow (m3/s) (273K, 11%, dry) 36.74 36.74

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Parameter / Source Line 1 Line 2 Emission Temperature (a) (K) 423.0 423.0 (a) Oxygen Content (% O2 wet gas) 7.0 7.0 (a) Moisture content (% H2O) 19.3 19.3 Actual Flow Rate (Am3/s) 57.23 57.23 Emission velocity (m/s) 15.76 15.76

5.4 Applied Emission Rates

The applied emission rates are presented in Table 5-2 and have been calculated from the process conditions detailed in Table 5-1 above and the daily average WID emission limits as detailed in Table 2-3.

Table 5-2 Emission Rates from Kingswood ERF (per line)

Pollutant Emission Rate (g/s) per line Nitrogen Dioxide 7.348 Particulate Matter 0.367 Sulphur Dioxide 1.837 Carbon Monoxide 1.837 Hydrogen Chloride 0.367 Hydrogen Fluoride 0.037 Organics (TOC) 0.367 Metals (Group 1, per metal) 9.18E-04 Metals (Group 2, per metal) 1.84E-03 Metals (Group 3, per metal) 2.04E-03 Dioxins 3.67E-09 Ammonia 0.367 Note: As there are 2 lines proposed, the emission rates in this table must be doubled in order to calculate the total emission from the facility (based on emission at daily WID emission limits).

5.5 Dispersion Model Set-up

The Agency’s H1 guidance provides a screening methodology for determining those pollutants that require detailed modelling. For the purposes of the EIA the full H1 assessment has not been undertaken as all pollutants have been subjected to detailed dispersion modelling.

5.5.1 Modelling Scenarios

For the purposes of the dispersion modelling of emission (i.e. process contribution) from the Kingswood ERF stacks; one scenario has been defined (2014, the year of first operation).

5.5.2 Stack Height Determination

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Biffa have designed the facility with a stack height of 90m. This height in line with other ERF’s in the UK and has been demonstrated at other sites to achieve sufficient dispersion and minimisation of building wake effects. Further increases in stack height do not achieve significant increases in dispersion and are therefore not considered to be justified. Refer to section 7.0 for further details of the stack height determination.

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5.5.3 Meteorological Data

As described briefly earlier, meteorological data used in this assessment comprised a 5-year sequential hourly average dataset from Coleshill observation station, over the period 1st January 2004 to 31st December 2008 (inclusive). Five year met data was used to comply with current EA modelling guidance. This accounts for inter-year variability in meteorological conditions, with the average of the 5-year data set being used.

The meteorological data for Coleshill was obtained in .met format from the data supplier and converted to .the required surface and profile formats for use in AERMOD using AERMET Pro. Details specific to the exact site location were used for the conversion, such as latitude, longitude and surface characteristics in accordance with the latest guidance20. The surface characteristics were applied as shown in Table 5-3. The Bowen / albedo has been calculated on a ratio of 2% water, 2% forest, 28% cultivated land, 28 % grassland and 40% urban.

Table 5-3 Met Data Preparation – Applied Surface Characteristics

Zone (Start) Zone (end) Landscape Character Albedo Bowen Roughness 330 150 Cultivated Land 0.2497 1.1455 0.0725 150 330 Urban 0.2497 1.1455 1.0

5.5.4 Urban/Rural Classification

For the purposes of this assessment the ‘urban’ classification option is not considered to be appropriate as Cannock is on the margins of the Birmingham metropolitan area. The ‘urban’ option utilises different calculations to estimate the night time boundary layer based on the urban heat island effects associated with schemes within larger cities. This results in a lowering of boundary layer from a ‘rural’ setting and therefore the potential for increased ground level impacts. The effects of the urban classification have been investigated and are discussed in Section 7.

5.5.5 Terrain Data

The model was run with OS 1:50,000 scale digital height contour data at 10m vertical intervals. Data was processed by the AERMAP function within AERMOD to calculate terrain heights, and interpolate data to calculate terrain heights for sources, buildings etc. The ground level elevations for buildings within the application site have been manually corrected to reflect site survey data.

The effects of topography have been investigated and are discussed in Section 7.

5.5.6 Assessment Area

The potential air quality impact of the proposed plant was assessed over an area covering 10km radius from the development site. For human receptors, a stratified (polar) object array was selected in order to give more precise pollutant concentration predictions in the immediate vicinity of the site:

 150m grid spacing within 5km of the site; and

20 AERMOD Implementation guide. AERMOD implementation workgroup, USEPA. Last revised January 8, 2008.

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 250 m grid spacing 5km – 10km from the site.

The resolution of the finer grid (150m) is approximately 1½ the proposed Kingswood ERF stack height (90m). In total, impact was determined at 7,220 receptors for the pollutants associated with air quality impacts. Separate discrete receptor arrays were used for the ecological impacts.

The effects of grid resolution have been investigated and are discussed in Section 7.

5.5.7 Building Downwash

The integrated Building Profile Input Programme (BPIP) module within AERMOD was used to assess the potential impact of building downwash upon predicted dispersion characteristics. Building downwash occurs when turbulence, induced by nearby structures, causes pollutants emitted from an elevated source to be displaced and dispersed rapidly towards the ground, resulting in elevated ground level concentrations. Building downwash should always be considered for buildings that have a maximum height equivalent to at least 40% of the emission height, and which within a distance defined as five times the lesser of the height or maximum projected width of the building.

The effects of building downwash have been investigated and are discussed in Section 7.

5.5.8 Special Treatment of Results

Nitric Oxide to NO2 Conversion

Oxides of nitrogen (NOx) emitted to atmosphere as a result of combustion will consist largely of nitric oxide (NO), a relatively innocuous substance. Once released into the atmosphere, NO is oxidised to NO2. The proportion of NO converted to NO2 depends on a number of factors including wind speed, distance from the source, solar radiation and the availability of oxidants, such as ozone (O3).

The Environment Agency’s guidance on conversion ratios for NOx and NO2 (issued by AQMAU) has been applied and a ‘worse case’ scenario has been used for calculations. On this basis, 35% of NOx is presented as NO2 in relation to short term impacts and 70% of NOx is present as NO2 in relation to long term impacts.

Sulphur Dioxide – 15 minute averaging period

As dispersion models utilise hourly average meteorological data, calculation of 15-minute averages, such as required for SO2, requires the application of conversion factors. For the purposes of detailed modelling of SO2, a conversion factor of 1.34 is applied to hourly average data as detailed in EPR Guidance Note H1.

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6.0 PREDICTION OF IMPACTS

6.1 Predicted Short-term Impacts

Isopleths only only been generated for pollutants where the predicted short-term process contributions are greater than 10% of the relevant air quality standard (i.e. are significant). In this case, there are no significant short term pollutants.

A summary of the peak predicted short-term process contributions (PC) from the proposed Kingswood ERF facility is presented in Table 6-1.

Table 6-1 Predicted Short-term Process Contributions PC (µg/m3)

Applied PC Max as % Pollutant Av. Period PC Max Standard of Standard

NO2 200 1-hr 99.79%ile 5.377 2.7%

PM10 50 24-hr 90.41 %ile 0.161 0.3% CO 10000 8 hour 3.255 <0.1%

SO2 (15-min) 267 15-min 99.90%ile 5.084 1.9%

SO2 (1-hr) 350 1-hr 99.73%ile 3.794 1.1%

SO2 (24-hr) 125 24-hr 99.18%ile 1.516 1.2% HCl 750 1-hour max 0.995 0.1% HF 160 1-hour max 0.010 <0.1% Benzene (TOC 208 1-hour max 0.995 0.5% surrogate) Antimony 150 1-hour max 0.006 <0.1% Chromium (II and III) 150 1-hour max 0.005 <0.1% Copper 200 1-hour max 0.006 <0.1% Manganese 1500 1-hour max 0.006 <0.1% Mercury 7.5 1-hour max 0.005 0.1% Vanadium 1 24-hour 0.003 0.3% Note: No ST EAL’s exist for some WID pollutants (refer to Table 2-3)

These maximum impacts relate to the highest predicted level of impact at any location on the receptor grid and impacts at all other locations will be lower.

The predicted short-term PC is combined with the background concentration to identify the predicted environmental concentrations (PEC). The resultant significance of impact is presented in

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Table 6-2.

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Table 6-2 Predicted Short-term Predicted Environmental Concentrations (PEC) (µg/m3) Applied PEC Max as % Pollutant Standard Background PEC Max of Standard

NO2 200 36.4 41.8 20.9%

PM10 50 38.2 38.4 76.7% CO 10000 1600 1603.3 16.0%

SO2 (15-min) 267 8.2 13.3 5.0%

SO2 (1-hr) 350 8.2 12.0 3.4%

SO2 (24-hr) 125 8.2 9.7 7.8% HCl 750 13.2 14.2 1.9% HF 160 0.092 0.1 0.1% Benzene (TOC 208 0.86 1.9 0.9% surrogate) Antimony 150 --- 0.006 <0.1% Chromium (II and III) 150 0.0038 0.010 <0.1% Copper 200 0.032 0.038 <0.1% Manganese 1500 0.0182 0.024 <0.1% Mercury 7.5 0.0088 0.014 0.2% Vanadium 1 0.0028 0.006 0.6% *No background monitoring data is available for Antimony (refer to Section 4.4.3)

All short term predicted environmental concentrations are ‘well below’ relevant limits (i.e. are below 75%) with the exception of PM10. As can be seen from Table 6-1, this is almost entirely due to background sources.

6.2 Predicted Long-term Impacts

Predicted long-term impacts from the detailed modelling are presented in isopleth plots of the modelled scenarios in Drawings AQ1 to AQ6. Isopleths have only been generated for pollutants where the predicted long-term process contributions are greater than 1% of the relevant air quality standard.

A summary of the peak predicted long-term process contributions (PC) from the Kingswood ERF is presented in Table 6-3.

Table 6-3 Predicted Long-term Process Contributions (µg/m3) Applied Standard PC Max as % of Pollutant PC Max (Annual Mean) Standard

NO2 40 0.709 1.8%

PM10 40 0.051 0.1%

PM2.5 25 0.051 0.2% HF 16 0.005 <0.1% TOC 5 0.051 1.0% Arsenic 0.003 2.81E-04 9.4%

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Applied Standard PC Max as % of Pollutant PC Max (Annual Mean) Standard Antimony 5 2.81E-04 <0.1% Cadmium 0.005 1.27E-04 2.5% Chromium III 5 2.78E-04 <0.1% Chromium VI 0.0002 2.81E-06 1.4% Copper 10 2.81E-04 <0.1% Lead 0.25 2.81E-04 0.1% Manganese 150 2.81E-04 <0.1% Mercury 0.25 2.53E-04 0.1% Nickel 0.02 2.81E-04 1.4% Vanadium 5 2.81E-04 <0.1%

All process contributions except NO2, TOC, arsenic, cadmium, chromium VI and nickel are less than 1% of the applicable standard.

The predictions for dioxins have been used to inform the human health impact assessment in the absence of a concentration limit, and are therefore reported separately. Similarly, the impacts of ammonia have been used to inform the ecological assessment rather than the human impact assessment and are therefore not compared against EAL’s for protection of human health.

The predicted long-term PCs from the Kingswood ERF are combined with the background concentration to identify the predicted environmental concentrations (PEC) as presented in Table 6-4.

Table 6-4 Predicted Long-term Predicted Environmental Concentrations (µg/m3) Applied PEC Max as % Pollutant Standard Background PEC Max of Standard

NO2 40 18.20 18.91 47.3%

PM10 40 19.10 19.15 47.9%

PM2.5 25 12.20 12.25 49.0% HF 16 0.05 0.05 33.3% TOC 5 0.43 0.48 0.3% Arsenic 0.003 1.0E-03 1.3E-03 42.7% Antimony 5 --- 2.8E-04 --- Cadmium 0.005 5.0E-04 6.3E-04 12.5% Chromium III 5 2.00E-03 2.28E-03 <0.1% Chromium VI 0.0002 1.00E-04 1.00E-04 50.0% Copper 10 1.6E-02 1.6E-02 0.2% Lead 0.25 1.9E-02 1.9E-02 7.8% Manganese 150 9.1E-03 9.4E-03 <0.1% Mercury 0.25 4.4E-03 4.7E-03 1.9% Nickel 0.02 1.1E-03 1.4E-03 6.9% Vanadium 5 1.4E-03 1.7E-03 <0.1%

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*There are no appropriate background values to apply for Antimony to determine a PEC.

All annual average predicted environmental concentrations are ‘well below’ relevant limits (i.e. are below 75%).

6.3 Results –Sensitive Ecosystems

For all of the impacts described below, the result has been presented which represents the highest impact within the interest feature. For example, the result for the Cannock Chase SAC is the highest of 791 discrete points. Clearly in the event that a process contribution appears significant, this would be discussed in more detail for that particular interest feature.

6.3.1 Critical Levels

Nitrogen Oxides

The predicted concentration of NOx at sensitive ecosystem receptors is provided in the table below. All results are presented as annual averages.

Table 6-5 Predicted Nitrogen Oxide Impacts on Sensitive Ecosystems (µg/m3) Process PC as % of Feature Critical Level Contribution Critical Level Cannock Extension Canal SAC 30.0 0.14 0.48% Cannock Chase SAC 30.0 0.13 0.43% Stowe Pool And Walk Mill Clay Pit SSSI 30.0 0.07 0.24% Biddulphs Pool and No Mans Bank SSSI 30.0 0.13 0.44% Chasewater Heaths SSSI 30.0 0.11 0.36%

Predicted impacts (PC) from the Kingswood ERF are less than 1% of the applied critical level at all assessed receptors and the impact is therefore insignificant.

Sulphur dioxide

The predicted concentration of SO2 at sensitive ecosystem receptors is provided in the table below. All results are presented as annual averages.

Table 6-6 Predicted Sulphur Dioxide Impacts on Sensitive Ecosystems (µg/m3) Process PC as % of Feature Critical Level Contribution Critical Level Cannock Extension Canal SAC 20.0 0.05 0.26% Cannock Chase SAC 20.0 0.05 0.23% Stowe Pool And Walk Mill Clay Pit SSSI 20.0 0.03 0.13% Biddulphs Pool and No Mans Bank SSSI 20.0 0.05 0.24% Chasewater Heaths SSSI 20.0 0.04 0.19%

Predicted impacts (PC) from the Kingswood ERF are less than 1% of the applied critical level at all assessed receptors and the impact is therefore insignificant.

Ammonia

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The predicted concentration of ammonia at sensitive ecosystem receptors is provided in the table below. All results are presented as annual averages.

Table 6-7 Predicted Ammonia Impacts on Sensitive Ecosystems (µg/m3) Process PC as % of Feature Critical Level Contribution Critical Level Cannock Extension Canal SAC 3.0 0.010 0.34% Cannock Chase SAC 3.0 0.009 0.30% Stowe Pool And Walk Mill Clay Pit SSSI 3.0 0.005 0.17% Biddulphs Pool and No Mans Bank SSSI 3.0 0.009 0.32% Chasewater Heaths SSSI 3.0 0.008 0.26%

Predicted impacts (PC) from the Kingswood ERF are less than 1% of the applied critical level at all assessed receptors and the impact is therefore insignificant. There is no evidence to suggest that lichens and bryophytes are a significant feature of the Cannock Extension Canal SAC, and on this basis there is no apparent requirement to apply the more stringent limit applicable to these species (i.e. 1 µg/m3).

Hydrogen Fluoride (24-hr)

The predicted concentration of HF at sensitive ecosystem receptors is provided in the table below.

Table 6-8 Predicted HF Impacts on Sensitive Ecosystems (µg/m3) Process PC as % of Feature Critical Level Contribution Critical Level Cannock Extension Canal SAC 5.0 0.002 0.03% Cannock Chase SAC 5.0 0.002 0.03% Stowe Pool And Walk Mill Clay Pit SSSI 5.0 0.001 0.02% Biddulphs Pool and No Mans Bank SSSI 5.0 0.002 0.03% Chasewater Heaths SSSI 5.0 0.001 0.03%

Predicted impacts (PC) from the Kingswood ERF are less than 1% of the applied critical level (daily mean) at all assessed receptors and the impact is therefore insignificant.

6.3.2 Acid Deposition

A summary of the predicted impacts on the SSSI’s are presented in the following table.

Table 6-9 Predicted Acid Deposition on Sensitive Ecosystems (kgeq/hr/yr)

Feature Process Contribution Cannock Extension Canal SAC 0.010 Cannock Chase SAC 0.009 Stowe Pool And Walk Mill Clay Pit SSSI 0.005 Biddulphs Pool and No Mans Bank SSSI 0.009 Chasewater Heaths SSSI 0.007

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A critical load function graph has been provided for the SAC in line with the approach taken by APIS.

Figure 6-1 Cannock Chase SAC Critical Load Function

MaxCl MinCl Baseline PEC

2 1.8 1.6 1.4 1.2 1 0.8 0.6

S deposition (keq/ha/yr) deposition S 0.4 0.2 0 0 0.5 1 1.5 2 2.5 N deposition (keq/ha/yr)

The critical load function demonstrates that the acidity is already within the critical load range for the Cannock Chase SAC heathland habitat and will remain so with the ERF in place.

The Cannock Extension Canal is not recorded as being acid sensitive.

6.3.3 Eutrophication (Nitrogen Deposition)

A summary of the predicted impacts are presented in the following table with deposition rates for nitrogen as NOx and as NH3 presented separately. Nutrient nitrogen critical loads are only available for the following features.

Table 6-10 Predicted Nitrogen Deposition on Sensitive Ecosystems (kg/hr/yr)

Combined NOx and NOx-N deposition NH3 N deposition Critical NH3-N Deposition Ref Load PC as % PC as % PC as % (CL) PC of lower PC of lower PC of CL CL CL Cannock Chase 10-25 0.02 0.18% 0.05 0.48% 0.07 0.66% SAC Chasewater 10-25 0.02 0.16% 0.04 0.40% 0.06 0.56% Heaths SSSI Biddulph's Pool & 10-25 0.02 0.19% 0.05 0.49% 0.07 0.68% No Man's Bank

The highest Predicted impacts (PC) from the Kingswood ERF as a proportion of the critical load are at the Biddulph's Pool & No Man's Bank SSSI and are in the range 0.26 - 0.68% at the point of highest impact. There is no significant impact (i.e. above 1% of the critical load) at any site.

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6.4 Plume Visibility

A plume visibility model (ADMS) has been used to assess the hours when a plume is likely to be visible, and the length of the plume. This has been reported in the landscape and visual assessment prepared as part of the Environmental Statement (Section 7).

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7.0 DISPERSION MODEL SENSITIVITY

The sensitivity of a dispersion model is defined in the ADMLC guidance21 as the differential of model output by model input. This guidance identifies the following key input variables for the dispersion model:

 Emission characteristics (including rate, height and velocity);  Meteorology, both annual and spatial variability;  Atmospheric chemistry;  Terrain;  Building effects; and  Receptor spacing.

The possible variation in emission rates from the process has been discussed separately to the sensitivity of the dispersion model itself in Section 7.6.

7.1 Stack Height Variation

A stack height determination was completed as part of the design process. The graph below shows the improvement in impact attributable entirely to height. The data presents % of short term and long term EALs.

Figure 7-1 Stack Height Implications –NO2

15.0%

14.0%

13.0%

12.0%

11.0%

10.0%

9.0%

8.0% 1 hour (%) 7.0% Annual (%)

6.0%

5.0%

4.0%

3.0%

2.0%

1.0%

0.0% 60m 65m 70m 75m 80m 85m 90m 95m 100m 105m 110m 115m 120m

21 Guidelines for the Preparation of Dispersion Modelling Assessment for Compliance with Regulatory Requirements – an update to the 1995 Royal Meteorological Society guidance. UK Atmospheric Dispersion Modelling Committee (ADMLC), Version 1.4, 2004

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For purposes of this stack height determination, NO:NO2 ratios have been taken as 100% for long term and 50% for short term. There is a benefit here of a stack at or above 85m, with additional benefits associated with every additional 1m diminishing for greater heights. Biffa have chosen a stack height of 90m.

7.2 Atmospheric Chemistry

Following the Environment Agency AQMAU guidance on conversion ratio for NOx and NO2, a worst case scenario has been applied in that 35% of NOx is presented as NO2 in relation to short term impacts and 70% of NOx is present as NO2 in relation to long term impacts. As a result of this ‘worst case’ approach, no further sensitivity assessment is considered to be required.

7.3 Typical MSW ERF Emissions

Operational experience of existing municipal waste incinerators suggests that both emissions of Group 3 metals and of particulates are significantly lower than the WID limits.

Table 7-1 below shows some typical ERF emission rates derived from UK emissions reporting.

Table 7-1 Typical22 ERF Emission Rates Emission Concentrations 3 UK Average as Number of Number of Pollutant (mg/Nm ) % of WID Facilities Data Points UK Average WID Limit Particles 3.4 10 34.4% 9 20 TOC 1.98 10 19.8% 9 19 HCl 7.41 10 74.1% 9 17 HF 0.66 1 66.5% 9 30

SO2 6.06 50 12.1% 9 15

NOx 198.2 200 99.1% 9 15 CO 23.0 50 46.0% 9 15

NH3 5.12 No limit - 6 14 Dioxins (g/m3) 0.035 0.1 34.6% 7 20 Group 1 Metals 0.0043 0.0043 8.5% 8 32 Group 2 Metals 0.0113 0.05 22.6% 8 33 Group 3 Metals 0.1440 0.5 28.8% 8 39 Table Note: NOx emissions include some facilities operating with derogation allowing NOx emission of up to 300mg/m3.

The Environment Agency have reported in decision documents for ERF that emissions data from 5 municipal waste incinerators over the past two years indicates emissions of Chromium of up to 0.014 mg/m3, and an average of 0.005 mg/m3. For Arsenic, emissions are of up to 0.015 mg/m3 with an average of 0.002 mg/m3. For Nickel, emissions are of up to 0.033 mg/m3 and an average of 0.01 mg/m3. On this basis assuming Chromium (VI) is 10% of total Chromium, emissions of Chromium (VI) are unlikely to exceed 0.0015 mg/m3.

22 Summarised from UK annual emissions reporting.

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7.4 Accident Scenarios (Abnormal Events)

The WID (article 13) allows for elevated emissions of some pollutants for limited periods of time during ‘abnormal operating conditions’.

These conditions relate to short-term disturbances or failure of the flue gas treatment (FGT) or continuous emission monitoring equipment. Under such abnormal operating conditions, waste feed to the plant must be stopped (Article 6(3)) and the plant is required to cease the incineration of waste as soon as practicable, within a maximum timeframe of 4 hours. Such abnormal operating conditions are only allowed to occur for 60-hours per year per line.

During these abnormal operating conditions, limits for emission to air still apply in relation to dust (150mg/m3 as a half-hourly average) and the WID emission limits remain applicable for TOC and CO.

The emission could potentially also be elevated from those set in the WID during emergency conditions where an exceedence of the emission limits could occur. An assessment of the likelihood of such an occurrence and the consequences in terms of impact on local air quality has been undertaken as detailed in the following sections.

7.4.1 Identification of Abnormal Operating Conditions

UK data23 shows that the reported occurrence of abnormal operating conditions (or exceedences of permitted emission limits) is very infrequent (far below the 60-hrs allowed for abnormal operating conditions under the WID).

This data indicates that ‘abnormal emissions’ are typically related to decreased performance of Flue Gas Treatment plant as opposed to exceedence of the permitted emission limit, with the exception of Carbon Monoxide where several short-term exceedences of the emission limits were reported.

Therefore based on this review of the annual reports for similar operational facilities in the UK, the following are considered to be examples of abnormal operating conditions which may lead to ‘abnormal emission levels’ of pollutants:

 Significant variation in waste composition (i.e. very high moisture) promoting poor combustion, leading to CO exceedences; or  Reduced efficiency of lime/bicarbonate injection system such as through blockages or failure of pumps leading to elevated acid gas emissions; or  Reduced efficiency of particulate filtration system due to bag failure and inadequate isolation, leading to elevated particulate emissions; or  Reduced efficiency of SNCR system as a result of blockages or failure of ammonia injection system, leading to elevated NOx emissions.

The design of the ERF indicates that the facility has significant duplication of systems and provision of standby equipment to ensure a high level of performance and compliance.

It is evident that the older (pre-1990) plants (i.e. Coventry, Edmonton, Nottingham, Stoke) are responsible for a majority of the reported abnormal operating conditions, whereas as more modern plant which were designed to comply with the requirements of the WID (such as Grimsby, Marchwood, Portsmouth and, Sheffield) demonstrate fewer occurrence of abnormal operating conditions.

23 All annual reports available from the Environment Agency.

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The proposed ERF would be a similar modern design to these and therefore a high degree of compliance would be anticipated. Therefore the identification of plausible abnormal emission levels has been based primarily on the data obtained from these more modern plants.

7.4.2 Plant Start-up and shut-down

Start-up of an ERF from cold is always conducted with clean support fuel (typically gas or gas oil). Waste is not introduced into the ERF unless the temperature is above the minimum requirement (850ºC) and other operating parameters (for example, air flow and oxygen levels) are within the range stipulated in the permit. During the warming up period the gas cleaning plant is fully operational as are all the control systems and monitoring equipment.

The same is true during plant shutdown. The waste remaining on the grate is allowed to burn out, the temperature not being permitted to drop below 850ºC by the simultaneous introduction of clean support fuel. After complete burnout of the waste, the burners are turned off and the plant is allowed to cool. During this period the gas cleaning equipment is fully operational, as are the control systems and monitoring equipment.

It should also be noted that start-up and shutdown are infrequent events; the ERF is designed to operate continuously, and ideally only close down for its annual maintenance programme.

In relation to the magnitude of Dioxin emissions during plant start-up and shut-down, recent research has been undertaken by AEA Technology on behalf of the Environment Agency24. Whilst elevated emissions of Dioxins (within 1 order of magnitude) were found during shutdown and start-up phases where the waste was not fully established on the grate, the report concluded that:

“The mass of dioxin emitted during start-up and shutdown for a 4-5 day planned outage was similar to the emission which would have occurred during normal operation in the same period. The emission during the shutdown and restart is equivalent to less than 1 % of the estimated annual emission (if operating normally all year).”

There is therefore no reason why such start-up and shut-down operations will affect the long-term impact of the facility.

7.4.3 Plausible Abnormal Emission Levels.

In addition to the daily average emission limits assessed in the main text of this report, the WID also stipulates half-hourly emission limit values (97th percentile). In theory this means that emissions can be at these elevated values for 3% of the time as long as compliance with the daily average values is still achieved.

There have also been documented events whereby facilities have emitted levels of pollutants which are above those specified under the WID. Under these circumstances, the facility would be in breach of the Environmental Permit and remedial action would be taken immediately. However, it is important to investigate the potential impacts under such circumstances (i.e. abnormal events) and the following plausible abnormal emission levels for the proposed ERF have been identified.

24 Investigation of Waste Incinerator Dioxins During start-up and shutdown operating phases. AEAT/ENV/R/2563 – Issue 1, AEA Technology on behalf of the Environment Agency, November 2008.

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Table 7-2 Plausible Abnormal Emissions from an ERF Permitted Emission (mg/m3) Plausible Abnormal % Above Max Emission(a) (mg/m3) Permitted Pollutant Daily Average ½ hourly max Emission

NOX 200 400 550 37.5% (b) PM10 10 30 37.5 25% SO2 50 200 280 40% CO 50 100 400 400% HCl 10 60 120 100% HF(c) 1 4 8 100% TOC (d) 10 20 40 100% Group 1 Metal (e) 0.025 0.031 25% Group 2 Metal (e) 0.05 0.063 25% Group 3 Metal (e) 0.056 0.069 25% Table Note: (a) Plausible Abnormal Emission Rates based on measured data from similar facility where available. (b) No measured data available; 25% increase based on approach used for Rufford ERF Permit Application and decision document. (c) No measured data available; 100% increase based on measured increase in HCl emissions. (d) No measured data available; 100% increase based on measured increase in HCl emissions. (e) Emission per metal. No measured data available; 25% increase based on applied increase to PM10 concentration and approach used for Rufford ERF Permit Application and decision document.

It should be noted that the definition of ‘abnormal operating conditions’ also encompasses periods where the continuous emission monitoring equipment is not operatively correctly and data relating to the actual emission concentrations are not available. This assessment has only used data where the concentration of continuously monitored pollutants has been quantified. Furthermore no data on flow characteristics (flow rate, temperate etc) during these abnormal operating conditions is available, so for the purposes of this assessment the design flow characteristics have been applied to the plausible emission levels to derive an emission rate and assess impact.

7.4.4 Plausible Abnormal emissions: Predicted Short-term Impacts

In order to assess the effect on short-tem ground level concentrations associated with the Ardley ERF operating at the identified plausible abnormal emission; the calculated ground level concentration has been increased pro-rata as presented in Table 7-3.

Table 7-3 Short-term Impacts Resulting from Plausible Abnormal Emissions (µg/m3) Pollutant EAL Predicted Impact – WID daily Predicted Impact – Plausible average Limits Abnormal Emission µg/m3 % of EAL µg/m3 % of EAL

NOX 200 5.38 2.69% 14.79 7.4% PM10 50 0.16 0.32% 0.60 1.2% SO2 267 5.08 1.90% 28.47 10.7% CO 10000 3.26 0.03% 26.04 0.3% HCl 750 0.99 0.13% 11.94 1.6% HF 160 0.01 0.01% 0.08 0.1% TOC 700 0.99 0.14% 3.98 0.6% Group 2 Metal 7.5 5.3E-03 0.07% 0.01 0.1% Group 3 Metal 1 5.9E-03 0.59% 7.3E-03 0.7%

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Pollutant EAL Predicted Impact – WID daily Predicted Impact – Plausible average Limits Abnormal Emission There are no Group 1 Metal short-term EAL’s. Group 3 Metal short-term impacts assessed against EAL for Vanadium (highest % impact against EAL).

The figures in the table have been calculated from figures rounded / up down by decimal places. On this basis, the percentage of the EAL may in all cases not appear accurate for the figure in the table.

This is considered to be a highly conservative assessment as it assumes that the plausible abnormal emissions coincide with worst-case meteorological conditions. Even with these highly conservative factors, there are no exceedences of any of the short-term air quality limits. The maximum predicted process contribution (as % of the applied EAL) is less than 11%.

7.4.5 Plausible Abnormal emissions: Predicted Long-term Impacts

In order to assess the effect on long-term ground level concentrations associated with the Ardley ERF operating at the identified plausible abnormal emission levels; the calculated long-term ground level concentrations have been increased pro-rata as presented in Table 7-4.

This assumes that the ERF is operating at the daily average WID emission limits for 8700 hours per year and at the plausible abnormal emission levels for 60 hours per year. Given this low frequency of occurrence, these plausible abnormal emissions are predicted to have little effect on long-term impacts as shown in Table 7-4.

The Environment Agency approach to CrVI apportionment has been described earlier. Stack data indicates that the actual fraction of chromium in the oxidation state VI could be as high as 10% - 13% for combustion process burning solid fuels25 and for this reason the sensitivity assessment below has taken this higher level into account.

Table 7-4 Long-term PC Impacts Resulting from Plausible Abnormal Emissions (µg/m3) Pollutant EAL Predicted Impact – WID daily Predicted Impact – Plausible average Limits Abnormal Emission µg/m3 % of EAL µg/m3 % of EAL

NOX 40 0.71 1.77% 0.72 1.79% PM10 40 0.05 0.13% 0.05 0.13% HF 16 0.005 0.03% 0.01 0.03% TOC 5 0.05 1.01% 0.05 1.03% Group 1 Metal (a) 0.005 1.3E-04 2.53% 1.3E-04 2.53% Group 2 Metal 0.25 2.5E-04 0.10% 2.5E-04 0.10% Group 3 Metal (b) 0.003 2.8E-04 9.37% 2.8E-04 9.39% Chromium VI (c) 0.0002 3.7E-05 18.27% 3.7E-05 18.30% Table Note: (a) Group 1 Metal short-term impacts assessed against EAL for Cadmium (lowest EAL). (b) Group 3 Metal short-term impacts assessed against EAL for Arsenic (lowest EAL). (c) Impact of Chromium VI assuming 13% of Cr present in oxidation state VI.

25 UK Particulate and Heavy Metal Emissions from Industrial Processes, Appendix B1. DEFRA 2002.

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As with Table 7-3 the figures in the table have been calculated from figures rounded / up down by decimal places. On this basis, the percentage of the EAL may in all cases not appear accurate for the figure in the table.

7.5 Annual Operating Hours

A typical ERF line requires a minimum of 3-weeks shutdown fro maintenance per year, therefore operational hours will never be in excess of 8256 hours and in the UK typically achieve between 8000 and 8200 operational hours per annum.

Therefore on this basis, it can be concluded that actual long-term (annual) emissions, (and resultant impacts) are likely to between 5.7% and 8.6% lower than modelled for this assessment.

7.6 Assessment of Model Sensitivities

In order to investigate the sensitivity of the dispersion model to variation in the remaining critical input parameters detailed previously, the following scenarios were investigated:

 Sensitivity 0 - Baseline;  Sensitivity 1 - Met Data: Shawbury Met Data used;  Sensitivity 2 - Met Data Preparation: Grass Roughness  Sensitivity 3 - Met Data Preparation: Urban Roughness  Sensitivity 4 - Met Data Preparation: Water Roughness  Sensitivity 5a – ‘Urban’ Tool, 25000 population  Sensitivity 5a – ‘Urban’ Tool, 50000 population  Sensitivity 5a – ‘Urban’ Tool, 100000 population  Sensitivity 6 – reduced actual flow (75% of baseline). Velocity reduced to 11.82 m/s, normalised flow (and mass emission) remains as baseline;  Sensitivity 7 – increased actual flow (125% of baseline). Velocity increased to 19.7 m/s, normalised flow (and mass emission) remains as baseline;  Sensitivity 8 – decreased temperature to 120C. All other parameters unchanged;  Sensitivity 9 – increased temperature to 180C. All other parameters unchanged;  Sensitivity 10 – Flat terrain;  Sensitivity 11 – No buildings;  Sensitivity 12 – Grid resolution set to 90m spacing over entire 10km radius;  Sensitivity 13 – Buoyancy / momentum test. Single stack, 3.0405m diameter. All other parameters unchanged;

These model sensitivity assessments were assessed using meteorological data from 2004, results are summarised in Table 7-5.

Table 7-5 Results of Model Sensitivity Assessment

Scenario Peak ST NO2 % of EAL Peak LT NO2 % of EAL 0 5.41 2.7% 0.68 1.7% 1 5.06 2.5% 0.71 1.8% 2 4.77 2.4% 0.34 0.9% 3 5.52 2.8% 0.69 1.7% 4 5.42 2.7% 0.27 0.7% 5a 17.68 8.8% 0.70 1.8% 5b 13.34 6.7% 0.66 1.7% 5c 10.20 5.1% 0.63 1.6%

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Scenario Peak ST NO2 % of EAL Peak LT NO2 % of EAL 6 4.85 2.4% 0.61 1.5% 7 4.85 2.4% 0.61 1.5% 8 5.82 2.9% 0.72 1.8% 9 5.13 2.6% 0.64 1.6% 10 5.48 2.7% 0.71 1.8% 11 5.41 2.7% 0.68 1.7% 12 5.41 2.7% 0.69 1.7% 13 3.94 2.0% 0.51 1.3%

The sensitivity modelling results show that the greatest influence tested is due to selection of the ‘Urban’ function in AERMOD.

On the basis of the results, none of the variations in the parameters investigated result is a material change to the conclusions, i.e. that the impact of the Kingswood ERF does not lead to any breach of the NO2 objectives. The range of influence may also be applied across all other pollutants, albeit the differences associated with percentiles and averaging periods must be considered.

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8.0 CUMULATIVE IMPACTS

As discussed in section 3.1.1 potential cumulative impacts associated with the following sites have been identified:

 Operation of the proposed Four Ashes EfW;  Operation of a 120000tpa AD facility to the north of the Poplars Landfill site; and  Operation of the existing and proposed landfill gas spark ignition engines.

Impacts at the Watling Street AQMA have also been investigated given the sensitivity of additional NOx impacts at this location.

8.1 Four Ashes (W2R) EfW

In May 2008 Staffordshire County Council applied for planning permission to build this facility to treat household waste and generate energy in the form of electricity and potentially heat. In November 2008 planning permission was approved.

The Four Ashes (W2R) site at The Dell, Enterprise Drive, covers 10 acres. The facility will generate at least 24.5 megawatts of electricity. It will be designed to have an operating lifespan of at least 25 years and will take three years to be built. Once built, it will operate on a seven day a week basis.

The Environmental Statement issued in support of the planning application is available on the web26. The air quality assessment (‘Air Quality, Health and Climate’, Chapter 6) provides detailed information relating to emissions from 80m stack. Further information is provided in ‘Appendix 6.1: Dispersion Model Results’. This data has been used to construct a cumulative impacts model.

The model inputs are shown below:

Table 8-1 Emissions from the W2R Facility

Parameter / Source Value Stack Location NGR (x,y) 392333, 308421 Stack Diameter (m) 2.97 Stack Exhaust Height (m) 80 NOx flow rate (g/s) 11.1 Emission Temperature (ºC) 125 Actual Flow Rate (Am3/s) 55.6 Emission velocity (m/s) 10.3

It has not been possible to accurately represent the W2R building in the model although the W2R application indicates that this is 158m long by 91.4m wide and 42m tall. A building influence would be expected.

Critically, the focus of this cumulative impacts model is to determine the impact of the current proposals, not those of the W2R facility. For this reason, the receptor grid has been retained

26 http://www.staffsprojectw2r.info/planningapplication/

SLR Biffa Waste Services Limited 50 402.0034.00320 Kingswood ERF: Technical Appendix 6/1 July 2010 as described in section 4.10. This is likely to result in the maximum ground level Process Contribution of the W2R facility being missed, however the impact of the W2R facility at the location of maximum GLC attributable to the Kingswood ERF will be determined and it is this cumulative impact which is tested here.

Table 6.14 of the W2R Environmental Statement reports that the maximum annual average 3 PC of NO2 is 2.1µg/m . This is approximately 3 times higher than for the current application. Of importance is that the cumulative annual average impact is also 0.7 µg/m3 indicating very little overlap of impacts for the two facilities.

Table 6.14 of the W2R Environmental Statement reports that the maximum hourly average 3 PC of NO2 is 30.0µg/m . This is approximately 5 times higher than that predicted for the current application (5.4 µg/m3). The cumulative annual average impact is also 5.4 µg/m3 indicating very little overlap of impacts for the two facilities.

In conclusion, the cumulative NOx impact of the W2R and the Kingswood ERF does not make a material difference to the conclusions of this report, in that the maximum ground level impact of the two plants would be below the objectives for this pollutant.

Impacts for other pollutants are predicted to be similarly small and the risk of exceedance of any EAL as a result of a cumulative impact from the two schemes is negligible.

8.2 Poplars AD Facility

An 80000tpa AD facility sited to the north of the Poplars landfill gained planning permission in 2009. Biffa intend to increase the size of this facility to 120000tpa. Emissions from the CHP gas engines will be exhausted through one centralised 22m stack.

Detailed dispersion modelling has been undertaken in support of the planning and Permit applications for the facility. This data has been used to construct a cumulative impacts sensitivity model.

Model 0 as described in section 7.6 above has been used for the basis of this sensitivity model. The model has been constructed with buildings with width, length and orientations taken from the dispersion modelling report for the AD.

It is considered that the cumulative modelling provides an indicative guide to the cumulative impact from the facilities given the available information.

The model inputs are shown below:

Table 8-2 Emissions from 120000tpa AD Facility

Parameter / Source Value Stack Location NGR (x,y) 399416,309575 Stack Diameter (m) 0.866 Basal Stack Elevation (m AOD) 147 Stack Exhaust Height (m) 22 NOx flow rate (g/s) 3.122 Emission Temperature (ºK) 718 Actual Flow Rate (Am3/s) 18.24 Emission velocity (m/s) 30.97

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The results of the cumulative modelling indicate that the maximum ground level PC from the two sources is:

3  3.98 µg/m for annual average NO2 (assuming 70% NOx conversion). This impact is predicted at boundary location OS GR 399443, 309839. At this location the impact of the Kingswood ERF is predicted to be 0.45µg/m3. This is not a location where annual objectives would be applicable in relation to relevant exposure. 3  21.6µg/m for hourly average NO2 (assuming 35% NOx conversion). This impact is predicted at boundary location OS GR 399342, 309809.5. The impact attributable to the Kingswood ERF is predicted to be 3.3µg/m3 at this location.

In conclusion, the cumulative NOx impact of the AD plant and the Kingswood ERF does not make a material difference to the conclusions of this report, in that the maximum ground level impact of the two plants would be below the objectives for this pollutant.

Impacts for other pollutants are predicted to be similarly small and the risk of exceedance of any EAL as a result of a cumulative impact from the two schemes is negligible.

8.3 Poplars LFG Utilisation Plant

The Poplars landfill includes a gas collection system to enable utilisation of landfill gas in accordance with the Landfill Directive. The impact of the LFG engines (existing and proposed) has been modelled by Golder Assocaites previously in support of the Permit application for the site. This data has been used to construct a cumulative impacts sensitivity model.

As with the AD plant, Model 0 as described in section 7.6 above has been used for the basis of this sensitivity model. The model inputs are shown below:

Table 8-3 Emissions from LFG Engines

Parameter / Source Units Existing Engines Proposed Engines (3 No. CAT 3516) (3 No. CAT3520) Stack Diameter (m) Per unit 0.57 0.57 Basal Stack Elevation (m AOD) Per unit 147 148 Stack Exhaust Height (m) Per unit 9.8 11.2 NOx flow rate (g/s) Total (all units) 2.25 3.36 Emission Temperature (ºK) Per unit 773 773 Actual Flow Rate (Am3/s) Per unit 3.72 5.57 Emission velocity (m/s) Per unit 14.6 21.8

The results of the cumulative modelling indicate that the maximum ground level PC from the two sources is:

3  21.06 µg/m for annual average NO2 (assuming 70% NOx conversion). This impact is predicted at boundary location OS GR 399546.1, 308911.4. At this location the impact of the Kingswood ERF is predicted to be 0.17µg/m3. This is not a location where annual objectives would be applicable in relation to relevant exposure. 3  109.8 µg/m for hourly average NO2 (assuming 35% NOx conversion). This impact is predicted at boundary location OS GR 399552.8, 308799.1. The impact attributable to the Kingswood ERF is predicted to be 1.7µg/m3 at this location.

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In conclusion, the cumulative NOx impact of the LFG Utilisation plant and the Kingswood ERF does not make a material difference to the conclusions of this report, in that the maximum ground level impact of the two plants would be below the objectives for this pollutant. The impact of the ERF is extremely small compared with the overall cumulative impact, with the LFG utilisation plant impacts responsible for the primary contribution at the location of maximum GLC.

8.4 Road Traffic: Cumulative Impacts

The NOx monitoring undertaken by SLR demonstrates that, as would be expected for an urban area intersected by A roads and a Motorway, levels of NOx and NO2 vary significantly within the region.

Although it is considered best practice to derive a general background level for modelling on industrial sources (in accordance with EP H1, for example), it may be appropriate to consider other sites where the source contribution is significant. Furthermore, it may be necessary to determine the impact of any pollutants at the location of any AQMA’s for that pollutant.

CCDC have declared an AQMA based on elevated levels of NOx. The area encompasses the A5 Watling Street between the junction with the A34 Walsall Road and the district boundary with South Staffordshire, and the stretch of the A460 Wolverhampton Road between the junction with the A5 Watling Street and the district boundary. This AQMA is less than 1km from the site boundary.

A dispersion modelling scenario has been run with 118 receptors running along the centre line of Walting Street. The model has been run for NO2 only as the pollutant for which the AQMA has been declared. The NOx:NO2 factor of 70% has been applied as in the full assessment. 5 years have been modelled and the average calculated. The 5 locations with highest impact have been presented below.

Table 8-4 Impacts on Watling Street (PC)

Location OS Xm Location OS Ym Annual Average NO2 concentration (µg/m3) 399916.50 309602.91 0.67 399943.00 309574.41 0.67 399880.69 309652.41 0.66 400011.19 309501.31 0.65 399822.19 309733.50 0.63

The highest impact is 1.7% of the annual average objective for NO2. This would normally be regarded as a ‘small’ impact magnitude in accordance with common practice27. Because the levels at this location are by definition above the objective (hence the AQMA designation), the impacts must be classified as ‘slight adverse’.

27 Environmental Protection UK (2010) Development Control: Planning for Air Quality.

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