Environmental Permit Appendices

Riverside Energy Park Environmental Permit Appendices

APPENDIX: AIR QUALITY ASSESSMENT

D DISPERSION MODELLING REPORT

December 2018 Revision 0 Riverside Energy Park Dispersion Modelling Report

Riverside Energy Park Dispersion Modelling Report

Contents

1 Introduction ...... 1 1.2 Project Description ...... 1 1.3 The Objective ...... 1 2 Legislation ...... 2 2.1 European Air Quality Legislation ...... 2 2.2 UK Air Quality Legislation and Strategy ...... 2 2.3 Industrial Pollution Regulation ...... 3 3 Air Quality Standards, Objectives and Guidelines ...... 7 3.1 Nitrogen dioxide ...... 7 3.2 Sulphur dioxide ...... 7 3.3 Particulate matter ...... 8 3.4 Carbon monoxide ...... 8 3.5 Hydrogen chloride ...... 9 3.6 Hydrogen fluoride ...... 9 3.7 Ammonia ...... 9 3.8 Metals ...... 9 3.9 Volatile Organic Compounds (VOCs)...... 10 3.10 Dioxins and furans ...... 11 3.11 Polychlorinated biphenyl (PCBs) ...... 11 3.12 Polycyclic Aromatic Hydrocarbons (PAHs) ...... 11 3.13 Summary ...... 11 4 Baseline Air Quality ...... 14 4.1 Summary ...... 14 5 Sensitive Receptors ...... 16 5.1 Human Sensitive Receptors ...... 16 5.2 Ecological Sensitive Receptors ...... 17 6 Dispersion Modelling Methodology ...... 21 6.1 Selection of model ...... 21 6.2 Chemistry ...... 25 6.3 Modelling assumptions ...... 25 7 Stack Height Analysis ...... 27 8 Impact on Human Health ...... 30 8.2 Screening ...... 30 8.3 Results ...... 30 8.4 ERF Only ...... 31 8.5 Biogas engine only ...... 33 8.6 Combined operation of ERF and biogas engine ...... 34 9 Impact at Ecological Receptors ...... 35

Riverside Energy Park Dispersion Modelling Report

9.2 Screening ...... 35 9.3 Atmospheric emissions - Critical Levels ...... 36 9.4 Deposition of emissions – Critical Loads ...... 36 9.5 Results – atmospheric emissions – Critical Levels ...... 38 9.6 Results – atmospheric emissions – Critical Loads ...... 39 9.7 Results – further analysis at Inner Thames Marshes SSSI...... 39 9.8 Results – further analysis at Ingrebourne Marshes SSSI ...... 40 9.9 Results - Biogas engine ...... 41 9.10 Results - Combined operation of ERF and biogas engine ...... 42 10 Conclusions ...... 43

Tables Table 2-1: IED Emission Limit Values – Annex VI, Part 3, para 1.1 to 1.4 ...... 3 Table 2-2: Best Available Techniques – Air Emission Levels ...... 4 Table 2-3: Medium Combustion Plant ELV for Engines ...... 6 Table 3-1: Environmental Assessment Levels (EALs) for Metals ...... 10 Table 3-2: Air Quality Assessment Levels (AQALs) ...... 12 Table 3-3: Critical Levels for the Protection of Vegetation and Ecosystems ...... 13 Table 4-1: Summary of background concentrations selected for use in this assessment ...... 14 Table 5-1: Human Sensitive Receptors ...... 16 Table 5-2: Ecological Sensitive Receptors ...... 18 Table 8-1: Annual Mean Cadmium Analysis ...... 32 Table 9-1: Screening Criteria...... 35 Table 9-2: Deposition Factors ...... 37 Table 9-3: Conversion Factors ...... 38 Table 9-4: Impact Analysis at Inner Thames Marshes SSSI ...... 39 Table 9-5 Impact Analysis at Ingrebourne Marshes SSSI ...... 40

iii

Riverside Energy Park Dispersion Modelling Report

1 Introduction

1.1.1 Cory Environmental Holdings Limited (trading as Cory Riverside Energy) (Cory or the Applicant) is applying to the Environment Agency (EA) under The Environmental Permitting (England and Wales) Regulations 2016 (Environmental Permitting Regulations) for an Environmental Permit (EP) to operate an integrated Energy Park, to be known as Riverside Energy Park (REP). REP would comprise waste treatment facilities together with an associated Electrical Connection.

1.2 Project Description

1.2.1 A detailed description of REP is presented in Sections 1.4 to 1.6 of the Supporting Information. REP would be constructed on land immediately adjacent to Cory’s existing RRRF, within the London Borough of Bexley and would complement the operation of the existing facility.

1.2.2 The main elements of REP would be as follows:

 Energy Recovery Facility (ERF): to provide thermal treatment of Commercial and Industrial (C&I) residual (non-recyclable) waste with the potential for treatment of (non- recyclable) Municipal Solid Waste (MSW);

 Anaerobic Digestion facility: to process food and green waste. Outputs from the Anaerobic Digestion facility would be transferred off-site for use in the agricultural sector as fertiliser or as an alternative, where appropriate, used as a fuel in the ERF to generate electricity;

 Solar Photovoltaic Installation: to generate electricity. Installed across a wide extent of the roof of the Main REP Building;

 Battery Storage: to store and supply additional power to the local distribution network at times of peak electrical demand. This facility would be integrated into the Main REP building; and

 On Site Combined Heat and Power (CHP) Infrastructure: to provide an opportunity for local district heating for nearby residential developments and businesses. REP would be CHP Enabled with necessary on site infrastructure included within the REP site.

1.3 The Objective

1.3.1 This Dispersion Modelling Assessment has been produced to support the EP application for REP. This report draws on the work carried out by Peter Brett Associates LLP (PBA) to support the Development Consent Order (DCO) application, however it has been produced specifically in accordance with the requirements of the Environment Agency (EA) to determine an EP application.

Riverside Energy Park Dispersion Modelling Report

2 Legislation

2.1 European Air Quality Legislation

2.1.1 European air quality legislation is consolidated under the Ambient Air Quality Directive 2008/50/EC, which came into force on 11 June 2008. This Directive consolidates previous legislation which was designed to deal with specific pollutants in a consistent manner and provides new air quality targets and limits for fine particulates. The consolidated Directives include:

 Directive 99/30/EC – the First Air Quality "Daughter" Directive – which sets Ambient Air Directive (AAD) Limit Values for nitrogen dioxide and oxides of nitrogen, sulphur dioxide, lead and particulate matter;

 Directive 2000/69/EC – the Second Air Quality "Daughter" Directive – which sets AAD Limit Values for benzene and carbon monoxide; and

 Directive 2002/3/EC – the Third Air Quality "Daughter" Directive – which seeks to establish long-term Target values, an alert threshold and an information threshold for concentrations of ozone in ambient air.

2.1.2 The Fourth “Daughter” Directive – 2004/107/EC - was not included within the consolidation. It sets health-based target values for polycyclic aromatic hydrocarbons, cadmium, arsenic, nickel and mercury, for which there is a requirement to reduce exposure to as low as reasonably achievable.

2.2 UK Air Quality Legislation and Strategy

2.2.1 The Air Quality Standards Regulations (2010) seek to transpose Directive 2008/50/EC and the Fourth “Daughter" Directive within the UK. The regulations also extend powers, under Section 85(5) of the Environment Act (1995), for the Secretary of State to give directions to local authorities for the implementation of these Directives.

2.2.2 The UK Air Quality Strategy (2007) is the method of implementation of the AAD Limit Values and Targets in England, Scotland, Wales and Northern Ireland. This document builds on the previous Strategy, published in 2000, and a 2003 Addendum.

2.2.3 The Air Quality Strategy defines “standards” and “objectives” in paragraph 17:

“For the purposes of the strategy:

 standards are the concentrations of pollutants in the atmosphere which can broadly be taken to achieve a certain level of environmental quality. The standards are based on assessment of the effects of each pollutant on human health including the effects on sensitive subgroups or on ecosystems; and

 objectives are policy targets often expressed as a maximum ambient concentration not to be exceeded, either without exception or with a permitted number of exceedances, within a specified timescale.”

2.2.4 The status of the objectives is clarified in paragraph 22, which also emphasises the importance of European Directives:

“The air quality objectives in the Air Quality Strategy are a statement of policy intentions or policy targets. As such, there is no legal requirement to meet these objectives except in as far as these mirror any equivalent legally binding limit values in EU legislation. Where UK

Riverside Energy Park Dispersion Modelling Report

standards or objectives are the sole consideration, there is no legal obligation upon regulators, to set Emission Limit Values (ELVs) any more stringent than the emission levels associated with the use of Best Available Techniques (BAT) in issuing permits under the PPC Regulations. This aspect is dealt with fully in the PPC Practical Guides.”

2.2.5 The UK Government consulted on a Draft UK Clean Air Strategy earlier this year. It is understood that the UK Government intends publishing the final Clean Air Strategy by March 2019.

2.3 Industrial Pollution Regulation

2.3.1 Atmospheric emissions from industrial processes are controlled in England through The Environmental Permitting (England and Wales) Regulations 2016, and subsequent amendments. REP will need an EP to operate. It is assumed that the EP will include conditions to minimise the environmental impact by:

 preventing fugitive emissions of dust and odour beyond the boundary of the permitted activity; and

 limiting emissions to air.

2.3.2 Compliance with these conditions will need to be demonstrated through continuous and periodic monitoring of emissions, as required by the EP.

Industrial Emissions Directive

2.3.3 Control of industrial emissions from large scale industrial plant is governed by the Industrial Emissions Directive (2010/75/EU) (IED). The IED incorporated the requirements of seven previous directives, including the Waste Incineration Directive (WID) (2000/76/EC). The design and operation of all plants which combust waste derived fuels must ensure compliance with ELVs set out in the IED. The ELVs applicable to the ERF that will form part of REP are shown in Table 2-1.

Table 2-1: IED Emission Limit Values – Annex VI, Part 3, para 1.1 to 1.4

30-Minute Mean Emissions(a) Daily Mean Substance Emissions(a) 100th percentile 97th percentile (mg/Nm3) (mg/Nm3) (mg/Nm3)

Nitrogen Oxides (NO and NO2) 200 400 200

Sulphur Dioxide 50 200 50

Carbon Monoxide 50 100 a 150 b

Total dust (Particles) 10 30 10

Hydrogen Chloride 10 60 10

Total Organic Carbon (TOC) 10 20 10

Hydrogen Fluoride 1 4 2

Group I metals – Cd and Tl c 0.05

Riverside Energy Park Dispersion Modelling Report

30-Minute Mean Emissions(a) Daily Mean Substance Emissions(a) 100th percentile 97th percentile (mg/Nm3) (mg/Nm3) (mg/Nm3)

Group II metals – Hg d 0.05

Group III metals – Sb, As, Pb, Cr, 0.50 Co, Cu, Mn, Ni and V d e

Dioxins and Furans 0.1 ng I-TEQ/Nm3

3 Emissions are mg/Nm . Normalised to 273 K, 101.3 kPa, dry, and 11% O2 a. 100th percentile of half-hourly average concentrations in any 24-hour period b. 95th percentile of ten-minute average CO concentrations c. Average over a sample period between 30 minutes and a maximum of 8 hours d. Average over a sampling period of 6 to 8 hours and calculated by multiplying with their toxic equivalence factor a. Other metals consist of antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni) and vanadium (V).

Waste Incineration BREF

2.3.4 The Best Available Techniques (BAT) Reference Document on Waste Incineration (herein referred to as the Waste Incineration BREF) is currently under consultation. It is understood that the ‘Final’ Waste Incineration BREF is expected to be published in 2019. Therefore, this will occur during the determination period for the EP application. The Draft Waste Incineration BREF has published ‘emission levels associated with the best available techniques’ (referred to as BAT-AELs) for waste incineration facilities such as the ERF.

2.3.5 In the Environmental Services Association Working Group meetings, which Cory have attended, the EA has advised that where a range is provided for the BAT AEL’s in the Waste Incineration BREF, as presented in Table 2-2, the upper end of the range will be applied with the exception of NOx, This is due to different NOx abatement technologies being more efficient at abating NOx than others. Therefore, the EA have indicated that an appropriate emission limit will be applied which will be dependent on the technology choice.

2.3.6 The relevant BAT – AELs for new plant are set out in Table 2-2. The assessment of emissions from the ERF has therefore been based on these BAT-AELs where they are lower than the IED ELVs. As set out in Table 6-2, this assessment has assumed that the Facility will operate at the 'upper range' of the BAT AEL's for new facilities, as stated within the Draft Waste Incineration BREF, with the exception of the emission limit for NOx. Cory are proposing the most efficient NOx abatement technology currently considered to represent BAT, as discussed in section 2.6 of the Supporting Information. Therefore, Cory is applying for an emission limit which is significantly lower than the upper range of the BAT AEL for NOx as stated within the draft Waste Incineration BREF.

Table 2-2: Best Available Techniques – Air Emission Levels

Daily Mean Emissions (a) Half-hourly Emissions (a) Substance (mg/Nm3) (mg/Nm3)

a Nitrogen Oxides (NO and NO2) 50 – 120 -

Sulphur Dioxide 10 – 30 -

Riverside Energy Park Dispersion Modelling Report

Daily Mean Emissions (a) Half-hourly Emissions (a) Substance (mg/Nm3) (mg/Nm3)

Carbon Monoxide 10 – 50 -

Total dust (Particles) 2 – 5 -

Hydrogen Chloride 2 – 6 -

Total Volatile Organic Carbon - 3 – 10 (TVOC)

Hydrogen Fluoride < 1 -

Ammonia 10 -

Cadmium and Thallium 0.01 – 0.02 -

Mercury 0.005 – 0.02 0.035b

Other metals c 0.05 – 0.3 -

< 0.01 – 0.06 ng WHO- Dioxins and Furans - TEQ/Nm3

3 Emissions are mg/Nm . Normalised to 273 K, 101.3 kPa, dry, and 11% O2 a. The lower range is appropriate where Selective Catalytic Reduction (SCR) is used and the upper range is appropriate where Selective Non-Catalytic Reduction (SNCR) is used. Other metals consist of antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni) and vanadium (V). b. Expressed as a maximum half-hourly c. Other metals consist of antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni) and vanadium (V)

2.3.7 It should be noted that the Waste Incineration BREF only includes a half-hourly value for mercury and that this is for guidance rather than being a mandatory requirement. Therefore, the half-hourly (and 10-minute) ELVs set out in the IED for all other pollutants would still apply. The daily mean emission limits set the emissions that will occur for the majority of the time and have therefore been used for the assessment of the impacts of emissions from ERF. However, there will be short periods where the emissions could be higher over a half-hourly period, albeit that the ERF will be constrained to the daily emission limit values. For those pollutants with allowable short-term emissions, an assessment has also been undertaken against relevant short-term assessment levels.

Medium Combustion Plant Directive

2.3.8 Directive 2015/2193/EU of the European Parliament and of the Council on the limitation of emissions of certain pollutants into the air from medium combustion plants has been implemented in England and Wales by The Environmental Permitting (England and Wales) (Amendment) Regulations 2018. The Medium Combustion Plant Directive imposes emission limits on medium combustion plant which combust biogas. Therefore, these emission limits will apply to the combustion of biogas generated by the Anaerobic Digestion plant. Table 2-3 provides the proposed ELVs for the biogas engine, if utilised.

Riverside Energy Park Dispersion Modelling Report

Table 2-3: Medium Combustion Plant ELV for Engines

ELV - Gaseous fuels other than natural Substance gas

Oxides of Nitrogen (NOx) 190

(a) Sulphur Dioxide (SO2) 40

3 Emissions are mg/Nm . Normalised to 273 K, 101.3 kPa, dry, and 15% O2 a. For biogas

Riverside Energy Park Dispersion Modelling Report

3 Air Quality Standards, Objectives and Guidelines

3.1.1 As discussed in Section 2.2, in the UK, AAD Limit Values, Targets, and air quality standards and objectives (AQOs) for major pollutants are described in The Air Quality Strategy (AQS). In addition, the EA include Environmental Assessment Levels (EALs) for other pollutants in EA’s guidance document 'Air Emissions Risk Assessment for your Environmental Permit' (Air Emissions Guidance). The long-term and short-term EALs from this document have been used when the AQS does not contain relevant objectives. Standards and objectives for the protection of sensitive ecosystems and habitats are also contained within the Air Emissions Guidance and the Air Pollution Information System (APIS). APIS (http://www.apis.ac.uk/) has been developed in partnership by the UK conservation agencies and regulatory agencies and the Centre for Ecology and Hydrology.

3.1 Nitrogen dioxide

3.1.1 All combustion processes produce nitric oxide (NO) and nitrogen dioxide (NO2), known by the general term of nitrogen oxides (NOx). In general, the majority of the NOx released is in the form of NO, which then reacts with ozone in the atmosphere to form nitrogen dioxide. Of the two compounds, nitrogen dioxide is associated with adverse effects on human health, principally relating to respiratory illness. The World Health Organisation (WHO) has stated that "many chemical species of nitrogen oxides exist, but the air pollutant species of most interest from the point of view of human health is nitrogen dioxide".

3.1.2 The major sources of NOx in the UK are road transport and energy generating stations, such as gas fired and coal fired power stations. According to the most recent annual report from the National Atmospheric Emissions Inventory (NAEI), road transport accounted for 37% of UK emissions, with power stations accounting for a further 27%. High levels of NOx in urban areas are almost always associated with high traffic densities.

3.1.3 The AQS includes two objectives to be achieved for the control of NOx by 31st December 2005. Both of these objectives are included in the Air Quality Directive, with an achievement date of 1st January 2010.

 A limit for the one-hour mean of 200 µg/m3, not to be exceeded more than 18 times a year (equivalent to the 99.79th percentile); and

 A limit for the annual mean of 40 µg/m3.

3.1.4 In addition, the AQS includes objectives for the protection of sensitive vegetation and ecosystems of 30 µg/m3 for the annual mean, and 75 µg/m3 for the daily mean concentration of NOx.

3.2 Sulphur dioxide

3.2.1 Sulphur dioxide is predominantly released by the combustion of fuels containing sulphur. Around 68% of UK emissions in 2004 were associated with power stations, with much of the remainder associated with other combustion processes. Emissions of sulphur dioxide have reduced by 87% since 1970, due to a reduction in the number of coal fired combustion plants, the installation of flue gas desulphurisation plants on a number of large coal-fired power stations and the reduction in sulphur content of liquid fuels.

3.2.2 The AQS contains three objectives for the control of sulphur dioxide:

Riverside Energy Park Dispersion Modelling Report

 A limit for the 15-minute mean of 266 µg/m3, not to be exceeded more than 35 times a year (the 99.9th percentile) to be achieved by 31 December 2005.

 A limit for the one hour mean of 350 µg/m3, not to be exceeded more than 24 times a year (the 99.73rd percentile) to be achieved by 31 December 2004.

 A limit for the daily mean of 125 µg/m3, not to be exceeded more than 3 times a year (the 99.2nd percentile) to be achieved by 31 December 2004.

3.2.3 The hourly and daily objectives are included in the Air Quality Directive.

3.2.4 In addition, the AQS includes two objectives for the protection of vegetation and ecosystems. These are a concentration of 20 µg/m3 (reduced to 10 µg/m3 where lichens or bryophytes are present) as an annual mean; and as a winter average.

3.3 Particulate matter

3.3.1 Concerns over the health impact of solid matter suspended in the atmosphere tend to focus on particles with a diameter of less than 10 µm, known as PM10s. These particles have the ability to enter and remain in the lungs. Various epidemiological studies have shown increases in mortality associated with high levels of PM10s, although the underlying mechanism for this effect is not yet understood. Significant sources of PM10s are road transport (22%), quarrying (16%) and stationary combustion (34%).

3.3.2 The AQS includes two objectives for PM10s to be achieved by the end of 2004, both of which are included in the Air Quality Directive.

 A limit for the annual mean of 40 µg/m3, to be achieved by 2004; and

 A daily limit of 50 µg/m3, not to be exceeded more than 35 times a year (the 90.4th percentile) to be achieved by 2004.

3.3.3 The previous AQS included some provisional objectives for 2010. These have been replaced by an exposure reduction objective for PM2.5s in urban areas and a target value for PM2.5s of 25 µg/m3 as an annual mean. This target value is included in the Air Quality Directive. It is noted that the draft Clean Air Strategy was released in May 2018, which proposes to progressively cut public exposure to particulate matter as suggested by the WHO. The aim is to halve the population living in areas with concentrations of fine particulate matter (PM2.5s) above the WHO guideline levels (10 µg/m3) by 2025. As this is a draft document, the AAD target value remains applicable for use.

3.4 Carbon monoxide

3.4.1 Carbon monoxide is produced by the incomplete combustion of fuels containing carbon. By far the most significant source is road transport, which produces 67% of the UK's emissions. Carbon monoxide can interfere with the processes that transport oxygen around the body, which can prove fatal at very high levels.

3.4.2 Concentrations in the UK are well below levels at which health effects can occur. The AQS includes the following objective for the control of carbon monoxide, which is also included in the Air Quality Directive:

 A limit for the 8-hour running mean of 10 mg/m3, to be achieved by 1st January 2005.

Riverside Energy Park Dispersion Modelling Report

3.5 Hydrogen chloride

3.5.1 There are no AQOs for hydrogen chloride contained within the AQS. However, the Air Emissions Guidance defines the short-term EAL as 750 µg/m3. There is no long-term EAL.

3.6 Hydrogen fluoride

3.6.1 There are no AQOs for hydrogen fluoride contained within the AQS. However, the Air Emissions Guidance defines the short-term EAL as 160 µg/m3 and the long-term EAL as 16 µg/m3.

3.6.2 The Air Emissions Guidance also provides Critical Levels for the Protection of Vegetation and Ecosystems (Critical Levels) of 5 µg/m3 as a daily mean and 0.5 µg/m3 as a weekly mean concentration of hydrogen fluoride.

3.7 Ammonia

3.7.1 There are no AQOs for ammonia contained within the AQS. However, the Air Emissions Guidance defines the short-term EAL as 2,500 µg/m3 and the long-term EAL as 180 µg/m3. The Air Emissions Guidance also provides Critical Levels. These are a concentration of 3 µg/m3 as an annual mean, reduced to 1 µg/m3 where lichens or bryophytes are present.

3.8 Metals

3.8.1 Lead is the only metal included in the AQS. Lead can have many health effects, including effects on the synthesis of haemoglobin, the nervous system and the kidneys. Emissions of lead in the UK have declined by 98% since 1970, due principally to the virtual elimination of leaded petrol.

3.8.2 The AQS includes objectives to limit the annual mean to 0.5 µg/m3 by the end of 2004 and to 0.25 µg/m3 by the end of 2008. Only the first objective is included in the Air Quality Directive.

3.8.3 The Fourth Daughter Directive on air quality (Directive 2004/107/EC) includes target values for arsenic, cadmium and nickel. However, the preamble to the Directive makes it clear that the use of these target values is relatively limited. Paragraph (5) states:

"The target values would not require any measures entailing disproportionate costs. Regarding industrial installations, they would not involve measures beyond the application of best available techniques (BAT) as required by Council Directive 96/61/EC of 24 September 1996 concerning integrated pollution prevention and control (5) and in particular would not lead to the closure of installations. However, they would require Member States to take all cost-effective abatement measures in the relevant sectors."

3.8.4 And paragraph (6) states:

"In particular, the target values of this Directive are not to be considered as environmental quality standards as defined in Article 2(7) of Directive 96/61/EC and which, according to Article 10 of that Directive, require stricter conditions than those achievable by the use of BAT."

3.8.5 Although these target values have been included in the assessment, it is important to note that the application of the target values would not have an effect on the design or operation of the ERF. The ERF will be designed in accordance with BAT and will include cost effective methods for the abatement of arsenic, cadmium and nickel, including the injection of activated carbon and a fabric filter.

Riverside Energy Park Dispersion Modelling Report

3.8.6 Emissions limits have been set in EPs for similar facilities for a number of heavy metals which do not have air quality standards associated with them. The EALs for these metals and lead are summarised in Table 3-1.

Table 3-1: Environmental Assessment Levels (EALs) for Metals

EAL (µg/m3) Daughter Directive Metal Target Level (µg/m3) Long-term Short-term

Arsenic 0.006 0.003 -

Antimony - 5 150

Cadmium 0.005 0.005 -

Chromium (II & III) - 5 150

Chromium (VI) - 0.0002 -

Cobalt - - -

Copper - 10 200

Lead - 0.25 -

Manganese - 0.15 1500

Mercury - 0.25 7.5

Nickel 0.020 0.020 -

Thallium - - -

Vanadium - 5 1

3.9 Volatile Organic Compounds (VOCs)

3.9.1 VOCs are a product of the combustion process; therefore, they will be released from the stack. Benzene and 1,3-butadiene are VOC’s which are included in the AQS and monitored at various stations around the UK. The AQS includes the following objectives for the running annual mean:

 Benzene – 5 µg/m3 to be achieved by 2010; and

 1,3-butadiene – 2.25 µg/m3 to be achieved by 2003.

3.9.2 The Air Emissions Guidance includes a short-term EAL for benzene, calculated from occupational exposure. This is a limit of 195 µg/m3 for an hourly mean. There are no short- term EALs for 1,3-butadiene.

Riverside Energy Park Dispersion Modelling Report

3.10 Dioxins and furans

3.10.1 Dioxins and furans are a group of organic compounds with similar structures, which are formed as a result of combustion in the presence of chlorine. Principal sources include steel production, power generation, coal combustion and uncontrolled combustion, such as bonfires. The European Municipal Waste Incineration Directive and UK legislation imposed strict limits on dioxin emissions in 1995, with the result that emissions from the combustion of municipal solid waste in the UK in 1999 were less than 1% of the emissions from energy recovery facilities in 1995. The Waste Incineration Directive, now included in the IED, imposed even lower limits, reducing the limit to one tenth of the previously permitted level.

3.10.2 One dioxin, 2,3,7,8-TCDD, is a definite carcinogen and a number of other dioxins and furans are considered to be possible carcinogens. A tolerable daily intake (TDI) for dioxins, furans and dioxins like PCBs has been recommended by the UK Committee on the Toxicity of Chemicals in Food, Consumer Products and the Environment of 2 pg I-TEQ per kg bodyweight per day.

3.10.3 Dioxins are not normally compared with set EALs, but the probable ingestion rates of dioxins by different groups of people is considered as part of the Human Health Risk Assessment, refer to Appendix D of the EP application.

3.11 Polychlorinated biphenyl (PCBs)

3.11.1 PCBs have high thermal, chemical and electrical stability and were manufactured in large quantities in the UK between the 1950s and mid 1970s. Commercial PCB mixtures, which contained a range of dioxin-like and non-dioxin like congeners, were sold under a variety of trade names, the most common in the UK being the Aroclor mixtures. UK legislative restrictions on the use of PCBs were first introduced in the early 1970s.

3.11.2 Although now banned from production, current atmospheric levels of PCBs are due to the ongoing primary anthropogenic emissions (e.g. accidental release of products or materials containing PCBs), volatilisation from environmental reservoirs which have previously received PCBs (e.g. sea and soil), or incidental formation of some congeners during the combustion process.

3.11.3 There are no AQOs for PCBs contained within the AQS. However, the Air Emissions Guidance defines the short-term EAL as 6 µg/m3 and the long-term EAL as 0.2 µg/m3.

3.11.4 A number of PCBs are considered to possess dioxin-like toxicity and are known as dioxin-like PCBs. The total intake from dioxins, furans and dioxins like PCBs is compared to the TDI for dioxins, furans and dioxin like PCBs as part of the Human Health Risk Assessment, included within Appendix D of the EP application.

3.12 Polycyclic Aromatic Hydrocarbons (PAHs)

3.12.1 PAHs are members of a large group of organic compounds widely distributed in the atmosphere. The best known PAH is benzo[a]pyrene (B[a]P). The AQS included an objective to limit the annual mean of B[a]P to 0.25 ng/m3 by the end of 2010. This goes beyond the requirements of European Directives, since the Fourth Daughter Directive on air quality (Commission Decision 2004/107/EC) includes a target value for benzo(a)pyrene of 1 ng/m3 as an annual mean.

3.13 Summary

3.13.1 AAD Target and Limit Values, AQS Objectives, and EALs are set at levels well below those at which significant adverse health effects have been observed in the general population and in particularly sensitive groups. For the remainder of this report these are collectively referred to

Riverside Energy Park Dispersion Modelling Report

as Air Quality Assessment Levels (AQALs). Table 3-2 and Table 3-3 summarise the air quality objectives and guidelines used in this assessment. The sources for each of the values can be found in paragraphs 3.1.1 to 3.12.1.

Table 3-2: Air Quality Assessment Levels (AQALs)

Limit Value 3 Pollutant (µg/m ) Averaging Period Frequency of Exceedances unless stated

18 times per year (99.79th 200 1 hour percentile) Nitrogen dioxide 40 Annual -

35 times per year (99.9th 266 15 minutes percentile)

24 times per year (99.73rd Sulphur dioxide 350 1 hour percentile)

3 times per year (99.18th 125 24 hours percentile)

35 times per year (90.41th 50 24 hours percentile) Particulate matter (PM10) 40 Annual -

Particulate matter (PM2.5) 25 Annual -

Carbon monoxide 10,000 8 hours, running -

Hydrogen chloride 750 1 hour -

Hydrogen fluoride 160 1 hour -

Thallium 16 Annual -

Ammonia 2,500 1 hour -

Lead 0.25 Annual -

5.00 Annual - Benzene 195 1 hour -

1,3-butadiene 2.25 Annual, running -

PCBs 6 1-hour -

0.2 Annual -

Riverside Energy Park Dispersion Modelling Report

Limit Value 3 Pollutant (µg/m ) Averaging Period Frequency of Exceedances unless stated

PAHs 0.00025 Annual -

Table 3-3: Critical Levels for the Protection of Vegetation and Ecosystems

Concentration Pollutant Measured as (µg/m3)

75 Daily mean Nitrogen oxides (as nitrogen dioxide) 30 Annual mean

Annual mean 10 for sensitive lichen communities and bryophytes and ecosystems where lichens and bryophytes Sulphur dioxide are an important part of the ecosystems integrity

Annual mean 20 for all higher plants

5 Daily mean Hydrogen fluoride 0.5 Weekly mean

Annual mean Ammonia 1 for sensitive lichen communities and bryophytes and ecosystems where lichens and bryophytes are an important part of the ecosystems integrity

Riverside Energy Park Dispersion Modelling Report

4 Baseline Air Quality

4.1 Summary

4.1.1 A detailed review of baseline concentrations has been undertaken as part of the DCO application. This is contained in Chapter 7 of the Environmental Statement (ES) which accompanied that application. A summary of the background concentrations selected for the use of this assessment is presented in the following table. These are the same as those used for the DCO application.

Table 4-1: Summary of background concentrations selected for use in this assessment

Pollutant Conc. Units Source

Nitrogen dioxide 16.6 µg/m3 DEFRA mapped background 2016

Max Location DEFRA background Sulphur dioxide 2 µg/m3 concentration calibrated against locally measured concentration at Rush Green

Particulates (PM10) 14.5 µg/m3 DEFRA mapped background 2016

Particulates (PM2.5) 9.7 µg/m3 DEFRA mapped background 2016

3 Carbon monoxide 0.5 mg/m London Marylebone for 2016

The ES chapter prepared for the site Hydrogen chloride 1 µg/m3 extension in 2014

The ES chapter prepared for the site Hydrogen fluoride 0.5 µg/m3 extension in 2014

Background Measurements are taken from Ammonia 2 µg/m3 London Cromwell 2 for 2016

VOCs (as benzene) 0.6 µg/m3 Chadwell St Mary for 2016

VOCs (as 1,3-butadiene) 0.3 µg/m3 DEFRA mapped background 2001

Mercury 2 ng/m3 Chilbolton Observatory for 2016

Cadmium 0.25 ng/m3 Chadwell St Mary for 2016

PaHs 0.2 ng/m3 Chadwell St Mary for 2016

The ES chapter prepared for the site Dioxins and Furans 8 fg/m3 extension in 2014

PCBs 0.118 ng/m3 London Nobel House for 2016

Arsenic 1 ng/m3 Chadwell St Mary for 2016

Antimony 1 ng/m3 Detling Station for 2013

Riverside Energy Park Dispersion Modelling Report

Pollutant Conc. Units Source

Chromium 3.2 ng/m3 Chadwell St Mary for 2016

Chromium (VI) 0.64 ng/m3 20% of the total chromium

Cobalt 0.1 ng/m3 Chadwell St Mary for 2016

Copper 11 ng/m3 Chadwell St Mary for 2016

Lead 11 ng/m3 Chadwell St Mary for 2016

Manganese 5 ng/m3 Chadwell St Mary for 2016

Nickel 1 ng/m3 Chadwell St Mary for 2016

Vanadium 1 ng/m3 Chadwell St Mary for 2016

Riverside Energy Park Dispersion Modelling Report

5 Sensitive Receptors

5.1.1 The general approach of this assessment is to evaluate the highest predicted process contribution to ground level concentrations, known as the point of maximum impact. In addition, the predicted process contribution at a number of sensitive receptors has been evaluated.

5.1 Human Sensitive Receptors

5.1.1 The human sensitive receptors identified for assessment are displayed in Appendix A.1 and listed in Table 5-1. These sensitive receptors are consistent with those assessed as part of the air quality works for the DCO application.

Table 5-1: Human Sensitive Receptors

Location ID Name Height (m) X Y

R1 The Business Academy 548447 179561 1.5

Belvedere Park housing R2 549598 179653 1.5 development

R3 St. Katherine's Road 547979 179883 1.5

R4 Wennington Road, Rainham 553700 180981 1.5

R5 Cherbury Close, Thamesmead 548054 181106 1.5

R6 Brady Primary School, Rainham 553036 181752 1.5

R7 Wennington Road/Anglesey Drive 552255 182069 1.5

R8 550720 182179 1.5 CEME Innovation Centre, Marsh Way R8B 550841 182170 1.5

R9 George Carey CofE Primary School 546451 182314 1.5

R10 Sovereign Road, Barking 547209 182983 1.5

R11 Spencer Road, South Hornchurch 550873 182892 1.5

R12 Shaw Gardens, near Scrattons Farm 548137 183305 1.5

Marsh Green Primary School, R13 549389 183528 1.5 Dagenham

St. Peter's Primary School, R14 548856 183584 1.5 Dagenham

R15 Beam Park Residential Development 550577 182914 1.5

Riverside Energy Park Dispersion Modelling Report

Location ID Name Height (m) X Y

R16 548203 179699 1.5 Education Facility R16B 548177 179598 4.5

R17 Lytham Close 548067 181170 1.5

R18A 1st 552137 182050 1.5 Celtic Farm Road R18B 4th 552137 182050 18

R19A 1st Clydesdale Way 549736 179858 13.5

R19B 6th Clydesdale Way 549736 179858 4.5

R20A GF 552160 182011 1.5 Capstan Drive R20B 5th 552160 182011 16.5

R21 Scrattons Terrace 547743 183541 1.5

R22 Rainham Village Children’s Centre 552403 182326 1.5

R23 5 Corinthian Road 550740 178649 1.5

R24 24 South Road 551583 177400 1.5

R25 41 Guild Road 551621 177360 1.5

R26 Voyagers Close 547291 151297 1.5

R27 Cornwall Road 555056 175662 1.5

5.1.2 The impacts of emissions from REP have been assessed at these receptor locations and are discussed in Section 8.

5.2 Ecological Sensitive Receptors

5.2.1 A study was undertaken to identify the following sites of ecological importance in accordance with the following criteria:

 Special Protection Areas (SPAs), Special Areas of Conservation (SACs), or Ramsar sites within 15 km of the Facility;

 Sites of Special Scientific Interest (SSSIs) within 15 km of the Facility; and

 National Nature Reserves (NNR), Local Nature Reserves (LNRs), Local Wildlife Sites (LWSs) and ancient woodlands within 2 km of the Facility.

Riverside Energy Park Dispersion Modelling Report

5.2.2 The screening distances for the statutory designated areas was agreed with the EA following consultation to support the DCO application. This identified that screening distances for statutory designated areas, with respect to assessing the effects from REP, should be extended to 15 kilometres (km). This screening distance has been used within the assessments in the EP application.

5.2.3 The sensitive ecological receptors identified as a result of the study are displayed in Appendices A.2 and A.3, and listed in Table 5-2. Natural England have published citations, which provide detailed information about European and UK designated habitat sites which have been designated for their wildlife or geological interest. A review of the citation and APIS website for each habitat site has been undertaken to determine if lichens are an important part of the ecosystem's integrity. If lichens are present, the more stringent Critical Level has been applied. Again, these sensitive receptors are consistent with those assessed as part of the air quality undertaken in support of the DCO application.

Table 5-2: Ecological Sensitive Receptors

Location Distance from the ID Name Designation ERF stack X Y (km)

ER1 Crossness 549322 179956 LNR 0.6

ER2 Lesnes Abbey 548822 178856 LNR 1.8

Inner Thames Marshes / 2.1 ER3 551372 181256 SSSI Rainham Marshes

ER4 Oxlees Woodland 544722 176156 SSSI 6.4

ER5(a) Gilbert's Pit (Charlton) 541872 178756 SSSI 7.7

ER6 Epping Forest 540475 186543 SSSI 10.7

ER7 Epping Forest 539772 188106 SSSI / SAC 12.2

ER8 Ingrebourne Marshes 552072 182506 SSSI 3.3

ER9 Thorndon Park 560222 191156 SSSI 15.1

ER10 Hainault Forest 548065 193119 SSSI 12.6

ER11 Curtismill Green 553222 195206 SSSI 15.1

ER12(a) Hornchurch Cutting 554672 187356 SSSI 8.6

ER13(a) Purfleet Chalk Pits 555972 178556 SSSI 6.9

West Thurrock Lagoon & 8.8 ER14 557272 176756 SSSI Marshes

ER15(a) Lion Pit 559772 178256 SSSI 10.6

ER16 Grays Thurrock Chalk Pit 560772 179106 SSSI 11.5

Riverside Energy Park Dispersion Modelling Report

Location Distance from the ID Name Designation ERF stack X Y (km)

ER17 Hangman's Wood & Deneholes 563122 179456 SSSI 13.8

ER18(a) Swanscombe Skull Site 559772 174356 SSSI 12.1

ER19(a) Bakers Hole 561072 174506 SSSI 13.2

ER20 Darenth Wood 557972 173106 SSSI 11.4

ER21 Farningham Wood 553722 168706 SSSI 12.7

ER22(a) Ruxley Gravel Pits 547572 170406 SSSI 10.3

ER23(a) Wansunt Pit 551497 173932 SSSI 7.0

ER24 BxB103 549683 178875 LWS 1.7

ER25 M039 551360 181215 LWS 2.1

ER26 M031 551066 181078 LWS 1.7

ER27 B&DB103 550010 181463 LWS 1.1

ER28 HvBI18 549898 181533 LWS 1.1

ER29 B&DBI07 548079 182156 LWS 2.0

Thamesmead Ecological Study 1.6 ER30 547855 181089 LWS Area

ER31 BxL07 548135 180661 LWS 1.3

ER32 BxBII02 548806 179546 LWS 1.2

ER33 BxL16 547975 180475 LWS 1.4

ER34 Lesnes Abbey 548850 178871 LWS 1.8

ER35 M041 549429 180755 LWS 0.2

ER36 M041_A 549429 180773 LWS 0.2

ER37 BxBI14 548405 181084 LWS 1.1

ER38 BxBI02 549686 180510 LWS 0.3

ER39 BxBII26 550642 179604 LWS 1.6

ER40 BxBII25 548524 180780 LWS 0.9

a. Sites designated for geological features,

Riverside Energy Park Dispersion Modelling Report

5.2.4 As indicated in the table above, designated sites have been designated for geological features (marked with an (a)) and are not sensitive to air pollution. Therefore, these designated sites have been excluded from the assessment.

5.2.5 Reference should be made to Appendix C.1 and C.2 for full details of the habitats present at each site and the habitat specific Critical Loads, as reported in APIS, refer to paragraph 9.4.1.

Riverside Energy Park Dispersion Modelling Report

6 Dispersion Modelling Methodology

6.1 Selection of model

6.1.1 Detailed dispersion modelling was undertaken by PBA for the DCO application, using the model ADMS 5.2, developed and supplied by Cambridge Environmental Research Consultants (CERC). This is a new generation dispersion model, which characterises the atmospheric boundary layer in terms of the atmospheric stability and the boundary layer height. In addition, the model uses a skewed Gaussian distribution for dispersion under convective conditions, to take into account the skewed nature of turbulence. The model also includes modules to take account of the effect of buildings and complex terrain. ADMS is routinely used for modelling of emissions for planning and Environmental Permitting purposes to the satisfaction of the EA and Local Authorities.

Model inputs

REP source and emissions data

6.1.2 The principal inputs to the model with respect to the emissions to air from REP are presented in Table 6-1.

Table 6-1: Source Data

Item Unit ERF – Per Line Biogas Engine

Stack data

m 90 – see stack height Height 8 analysis (Section 7)

Internal diameter m 2.2 0.64

Location m, m 549461, 180749 549391, 180594 549455, 180749

Flue gas conditions

Temperature °C 120 450

Exit moisture content % v/v 21.4% 10%

Exit oxygen content % v/v, dry 6.4% 10%

Reference oxygen content % v/v, dry 11% 15%

Volume at reference conditions Nm3/s 59.54 2.03 (0°C, dry, ref O2)

Volume at actual conditions Am3/s 74.45 3.24

Velocity m/s 19.585 10

Riverside Energy Park Dispersion Modelling Report

6.1.3 Emissions from the ERF have been assumed to comply with the BAT-AEL or ELVs set in the IED as discussed in Section 2.3 and set out in the following table. It should be noted that if the ERF continually operated at the half-hourly limits, the daily limits would be exceeded. The ERF would be designed to achieve the daily limits and as such will only operate at the shorter- term limits for short periods on rare occasions.

Table 6-2: ERF Emissions Modelled - Per Line

Pollutant Daily Half hourly

Limit (mg/Nm3) Release rate Limit Release rate (g/s) (mg/Nm3) (g/s)

Oxides of nitrogen (as NO2) 75 4.465 400 23.816

Sulphur dioxide 30 1.786 200 11.908

Carbon monoxide 50 2.977 100 5.954

Particulates (a) 5 0.298 30 1.786

Hydrogen chloride 6 0.357 60 3.572

Volatile organic compounds 10 0.595 20 1.191 (as TOC)

Hydrogen fluoride 1 0.060 4 0.238

Ammonia 10 0.595 - -

Cadmium and thallium (b) 0.02 1.191 µg/s - -

Mercury (b) 0.02 1.191 µg/s 0.035 2.084 µg/s

Other metals (b) (c) 0.3 17.862 µg/s - -

Benzo(a)pyrene (PAHs) (b)(d) 0.105 µg/Nm3 6.252 ng/s - -

Dioxins and furans 0.06 ng/Nm3 3.572 pg/s - -

PCBs (e) 0.005 0.298 µg/s - -

All emissions are expressed at reference conditions of dry gas, 11% oxygen, 273.15K. a. There have been limited measurements of PM2.5 emissions from waste incineration facilities. From information available on the EA’s public registers for waste incineration plants at Bolton, Stoke and Lewisham it is indicated that the PM2.5 faction makes up around 33% of the PM10 fraction. However, as a worst-case, it will be assumed that the entire PM emissions consist of either PM10 or PM2.5 for comparison with the relevant AQALs. b. ELV average over a sampling period of a minimum of 30 minutes and a maximum of 8-hours. c. Other metals consist of antimony (Sb), arsenic (As), lead (Pb), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni) and vanadium (V). d. The highest recorded emission concentration of B[a]P from the EA’s public register was 0.105 ug/m³, or 0.000105 mg/m³. This has been assumed to be the emission concentration for the ERF, to represent a conservative approach. e. The Waste Incineration BREF provides a range of values for PCB emissions to air from European municipal waste incineration plants. This states that the annual average total PCBs is less than 0.005 mg/Nm3 (dry, 11% oxygen, 273K). In lieu of other available data, this has been assumed to be the emission concentration for the ERF. 6.1.4 It should be noted that the proposed emission limit for NOx assumes that the ERF will include Selective Catalytic Reduction (SCR) for the abatement of NOx, refer to Section 4 of the BAT assessment – Appendix E of the EP application.

Riverside Energy Park Dispersion Modelling Report

6.1.5 Emissions from the biogas engine have been assumed to comply with the ELVs set in the MCPD as discussed in Section 2.3 and set out in Table 6-3.

Table 6-3: Biogas Engine Emissions Modelled

Pollutant Daily Half hourly

Limit Release Limit Release (mg/Nm3) rate (g/s) (mg/Nm3) rate (g/s)

Oxides of nitrogen (as NO2) 190 0.385 - -

Sulphur Dioxide 40 0.081 - -

All emissions are expressed at reference conditions of dry gas, 15% oxygen, 273.15K.

6.1.6 When the biogas engine is unavailable, the biogas would be flared in a 14 m high enclosed ground flare. The flare is estimated to operate between 200 and 400 hours per year. The exhaust gas temperature would be 850oC, with a calculated NOx emission rate of approximately 0.12 g/s (equivalent to 150 mg/Nm3). The flare emissions are therefore lower than from the biogas engine, and would be released at a higher temperature and from a higher stack. Therefore, the impact of the flare emissions would be lower than for the biogas engine.

Meteorological data and surface characteristics

6.1.7 The impact of meteorological data was taken into account by using weather data from London City Airport for the years 2013 – 2017. London City Airport is approximately 7 km to the west of REP. Five years of data are used to take into account inter-annual fluctuations in weather conditions. Wind roses from London City Airport for each year can be found in Appendix A.4.

Surface roughness

6.1.8 The surface roughness length can be selected in ADMS for both the dispersion and the meteorological site. This has been set to 0.5 m for the dispersion site, as recommended by the software provider for parkland, open suburbia, and 1.0 m for the meteorological site to reflect the urban location of London City Airport.

Monin-Obukhov length

6.1.9 The Monin-Obukhov length for the dispersion site and the meteorological site can be specified in ADMS. This provides a measure of the stability of the atmosphere and indicates the height above which convective turbulence (i.e. thermal) is more important than mechanical (i.e. friction). This allows for the effect of the urban heat island, to prevent the atmosphere from ever becoming very stable, to be simulated within the model.

6.1.10 The Monin-Obukhov length of the modelling domain has been set as 100 m for both the dispersion and meteorological site. This value is appropriate for large conurbations and is considered applicable for both the dispersion and meteorological sites given their proximity to large urban areas.

Modelling domain

6.1.11 Modelling has been undertaken over two domains; one for the biogas engine and a larger domain to account for the wider dispersion of pollutants from the ERF. It should be noted that these modelling domains are larger in extent than used in the DCO application to ensure that

Riverside Energy Park Dispersion Modelling Report

the maximum impact of emissions within all Air Quality Management Areas (AQMA’s) within the modelling domain could be reported, as well as presenting contour plots which include the distribution of emissions at areas of relevant exposure. In both instances, the maximum grid spacing in each is less than 1.5 times the stack height in accordance with the EA modelling rule of thumb. The modelling domain is shown in Appendix A.5.

Table 6-4: Modelling Domains

Grid Domain No.1 – ERF Domain No.2 – Biogas Engine

Grid Spacing (m) 90 12

Grid Start X 545000 548800

Grid Finish X 554000 550000

Grid Start Y 176200 180000

Grid Finish Y 185200 181200

Terrain

6.1.12 The software developers - CERC - recommend that, where gradients within 500 m of the modelling domain are greater than 1 in 10, the complex terrain module within ADMS (FLOWSTAR) should be used. A review of the local area has deemed that the effect of terrain does not need to be taken into account within the modelling.

Buildings

6.1.13 The presence of adjacent buildings can significantly affect the dispersion of the atmospheric emissions in the following ways:

 Wind blowing around a building distorts the flow and creates zones of turbulence. The increased turbulence can cause greater plume mixing; and

 The rise and trajectory of the plume may be depressed slightly by the flow distortion. This downwash leads to higher ground level concentrations closer to the stack than those which would be present without the building.

6.1.14 The Air Emissions Guidance recommends that buildings should be included in the modelling if they are both:

 Within 5L of the stack (where L is the smaller of the building height and maximum projected width of the building); and

 Taller than 40% of the stack.

6.1.15 The DCO application is applying for consent based on a Rochdale Envelope. This includes maximum building dimensions and the minimum stack height as a worst case assessment. For this EP application, analysis has been included of the impact of emissions based on this Rochdale Envelope but also based on stepped building form which more accurately reflects the detailed design that will be implemented in accordance with the Design Principles submitted with the DCO application and secured by a DCO requirement – referred to as 'the realistic stepped building'. The details of the buildings included within the model are presented

Riverside Energy Park Dispersion Modelling Report

in Table 6-5 and a site plan showing their location is presented in Appendix 0. All structures within 5L of the stack and taller than 40% of the stack have been included within the model.

Table 6-5: Building Details

Building Centre Point Length Width Height Angle (°) (m) (m) (m) X (m) Y (m)

Rochdale Envelope

Main REP Building 549458 180667 201 102 62 0

Anaerobic Digestion 549390 180615 88 45 40 0

Ancillary Process 549540 180618 111 115 35 0 Building

RRRF Building 549691 180650 145 77 37 0

Realistic stepped building

FGT 549458 180723.2 47.2 46 37 0

RV1_Main 549691.4 180649.9 145 77 37 0

Waste Bunker 549457.1 180635.9 43.73 68.63 42 0

Boiler Hall 549456.8 180678.5 42.75 53.31 52 0

Tipping Hall 549454.1 180598.2 32.47 62.38 30 0

6.2 Chemistry

6.2.1 The plant will release nitrogen monoxide (NO) and nitrogen dioxide (NO2) which are collectively referred to as NOx. In the atmosphere, a proportion of nitric oxide will be converted to nitrogen dioxide in a reaction with ozone which is influenced by solar radiation. Since the AQALs are expressed in terms of nitrogen dioxide, it is important to be able to assess the conversion rate of nitric oxide to nitrogen dioxide.

6.2.2 Ground level NOx concentrations have been predicted through dispersion modelling. Nitrogen dioxide concentrations reported in the results section assume 70% conversion from NOx to nitrogen dioxide for annual means and a 35% conversion for short term (hourly) concentrations, based upon the worst-case scenario in the EA’s guidance (2006) titled ‘Conversion rations for NOx and NO2’ methodology. Given the short travel time to the areas of maximum concentrations, this approach is considered conservative.

6.3 Modelling assumptions

6.3.1 For the operation of the ERF it is assumed that there are no maintenance or shut down periods and the source is emitting for 100% of the time. The emission rates have been calculated assuming that the source is emitting at full load at relevant emission limits where

Riverside Energy Park Dispersion Modelling Report

appropriate (as discussed in paragraphs 6.1.3 and 6.1.4). The modelling has been based on a maximum fuel throughput of 805,920 tpa which is greater than the nominal tonnage of 655,000 tpa and is therefore considered to be a robust and conservative assessment.

6.3.2 As explained in paragraph 1.5.1 of the Supporting Information, the biogas generated by the anaerobic digestion plant will be upgraded to a CNG. CNG would be the preferred option if feasible and viable. However, if a CNG option is not feasible or viable then REP will incorporate a “CHP engine” which would use the biogas to generate electricity and heat, which could be used to support the anaerobic digestion process or added to energy available for export from REP.

6.3.3 The combustion of the biogas in a biogas engine would provide a worst-case impact in terms of emissions. Therefore, this has been considered within this assessment.

6.3.4 The modelling of emissions from the ERF and biogas engine has been completed using 5- years of meteorological data and the maximum results reported for any of the five years modelled.

Riverside Energy Park Dispersion Modelling Report

7 Stack Height Analysis

7.1.1 The DCO application does not include a stack height analysis. However, it is noted that the EA requires confirmation that the stack height being applied for is appropriate for the building configuration. Therefore, this assessment has taken the models to develop the air quality assessment developed for the DCO application and re-run the assessment for a range of stack heights to show that the proposed stack height is appropriate. This has been carried out for both the Rochdale Envelope building and the realistic stepped building.

7.1.2 When determining a suitable stack height, it is best practice to identify the stack height where the rate of reduction in maximum ground level concentration with increased height slows down. This can be identified on a graph as a step change in the slope. This analysis has been carried out for the ERF in isolation.

7.1.3 The graphs below show the ground level concentration at the point of maximum impact as a percentage of the relevant AQAL for the range of stack heights for the ERF based on the Rochdale Envelope and the realistic stepped building design.

Graph 1 - Annual Mean Nitrogen Dioxide Stack Height Analysis – Point of Maximum Impact

Riverside Energy Park Dispersion Modelling Report

Graph 2 - Short Term Stack Height Analysis (1/2 hourly ELV) – Rochdale Envelope – Point of Maximum Impact

Graph 3 - Short Term Stack Height Analysis (1/2 hourly ELV) – Stepped Building Layout – Point of Maximum Impact

7.1.4 As shown in Graph 1, the Rochdale Envelope building has a much greater annual mean peak impact than the realistic stepped building, which is as expected due to the greater building downwash effects associated with the greater mass of building. Graph 2 and Graph 3 show the short-term impact of REP for different stack heights for the Rochdale Envelope and realistic stepped building. As with the annual mean impacts, the realistic stepped building has a much lower maximum impact due to there being less building downwash effect. For the proposed 90 m stack height and using the realistic stepped building design, all short-term impacts are less than 10% of the relevant AQAL and therefore screened out as ‘insignificant’ at the point of maximum impact.

Riverside Energy Park Dispersion Modelling Report

7.1.5 The peak impact occurs within the River Thames and not in any area of relevant public exposure. Graph 4 shows the peak NO2 concentration at the residential areas identified within all AQMA’s within the modelling domain. The residential areas are shown in Appendix A.1.

Graph 4 - Annual Mean Nitrogen Dioxide Stack Height Analysis – Maximum in Residential Areas in AQMA

7.1.6 As shown, with a stack height of 90m and using the realistic stepped building layout, the annual mean impact at areas of relevant exposure is less than 1% of the AQAL, and short- term impacts are all less than 10% of the AQAL and so are considered ‘insignificant’ using the screening criteria in Section 8.2. The impact of nitrogen dioxide and other pollutants is analysed in greater detail in Section 8.

7.1.7 This analysis shows that the proposed 90m high stack is appropriate for REP with both the Rochdale Envelope layout and the realistic stepped building, as the annual mean nitrogen dioxide impact is described as ‘insignificant’ in all AQMA’s within the modelling domain for both layouts, utilising the proposed NOx abatement technology (SCR) - refer to section 4 of the BAT Assessment. The remainder of this assessment has therefore been undertaken on the basis of a 90m high stack with the realistic stepped building layout.

Riverside Energy Park Dispersion Modelling Report

8 Impact on Human Health

8.1.1 The general approach of this assessment is to evaluate the highest predicted process contribution to ground level concentrations over the five modelled years (2013 - 2017), known as the point of maximum impact. In addition, the predicted impacts have been evaluated at the human sensitive receptors presented in section 5.

8.2 Screening

8.2.1 The Air Emissions Guidance states that to screen out 'insignificant' process contributions (PC’s):

 the long-term PC must be less than 1% of the long-term environmental standard; and

 the short-term PC must be less than 10% of the short-term environmental standard.

8.2.2 As part of this assessment, predicted process contributions have been compared to the AQALs provided in section 3.

8.2.3 If the above criteria are achieved, it can be concluded that "it is not likely that emissions would lead to significant environmental impacts", in accordance with the EA Guidance, and the process contributions can be screened out.

8.2.4 The long-term 1% process contribution threshold is based on the judgement that:

 it is unlikely that an emission at this level will make a significant contribution to air quality; and

 the threshold provides a substantial safety margin to protect health and the environment.

8.2.5 The short-term 10% process contribution threshold is based on the judgement that:

 spatial and temporal conditions mean that short-term process contributions are transient and limited in comparison with long-term process contributions; and

 the threshold provides a substantial safety margin to protect health and the environment.

8.2.6 For the purpose of this assessment, if the significance criteria are not exceeded at the point of maximum impact, further assessment is not required. If process contributions cannot be screened out, assessment will be undertaken for the following:

 the Predicted Environmental Concentration (PEC) (defined as the process contribution plus the background concentration) at the point of maximum impact; and

 the process contribution and PEC at areas of public exposure.

8.2.7 The EA Air Emissions Risk Guidance states that, if the long-term PEC is below 70% of the AQAL, or the short-term process contribution is less than 20% of the headroom, detailed modelling of emissions is not required. Therefore, if these criteria are met, it can be concluded that there is little risk of the PEC exceeding the AQAL, and the impact can be considered to be 'not significant'.

8.3 Results

8.3.1 The results results have been presented for the point of maximum impact. Where the impact at this point cannot be screened out as ‘insignificant’, further consideration has been made of

Riverside Energy Park Dispersion Modelling Report

the impact at sensitive receptors. The results have been presented for the ERF operating in isolation initially and then the in-combination impact with the biogas engine has been presented for those pollutants also released from the biogas engine (i.e. NOx and sulphur dioxide).

8.4 ERF Only

8.4.1 The detailed results tables are provided in Appendix B.1 to B.10 of this report. The contribution from the ERF operating in isolation based on the realistic stepped building with the proposed 90m high stack can be screened out as ‘insignificant’ for all pollutants and averaging periods with the exception of the following:

 Annual mean NO2 impacts;

 Annual mean VOCs impacts (as benzene or 1,3-butediene); and

 Annual mean cadmium impacts.

8.4.2 Further analysis of the above pollutants and averaging periods has been undertaken in paragraphs 8.4.3 to 8.4.11.

Annual mean NO2

8.4.3 As shown in Appendix B, the maximum annual mean nitrogen dioxide process contribution is predicted to be 1.7% of the AQAL. The contour plot is provided in Appendix A.8. The peak impact is predicted to occur within the River Thames. This is not considered to be an area of relevant exposure associated with the annual mean AQAL. The contour plot also shows the distribution for the Rochdale Envelope building layout, and shows that away from the buildings the predicted impact is similar for the Rochdale Envelope and realistic stepped building. This contour plot also shows that within all AQMA’s within the modelling domain that the process contribution is less than 1% of the AQAL and can be screened out as ‘insignificant’.

8.4.4 Detailed results at the identified sensitive receptors are provided in Appendix B.7. As shown, the impact at all sensitive receptors is less than 1% of the AQAL and can be screened out as ‘insignificant’.

Annual mean VOCs

8.4.5 As shown in Appendix B.1, the maximum annual mean VOC process contribution is predicted to be:

 2.5% of the AQAL for benzene; and

 5.6% of the AQAL for 1,3-butadiene

8.4.6 In all instances the predicted PEC is less than 70% and therefore can be described as ‘not significant’.

8.4.7 The contour plots are provided in Appendices A.9 and A.10. Again, the peak impacts are predicted to occur within the River Thames and this is not considered to be an area of relevant exposure associated with the annual mean AQAL.

8.4.8 Detailed results at the identified sensitive receptors are provided in, Appendix B.8 and B.9. As shown, although the impact cannot be screened out as ‘insignificant’, at all the identified receptor locations the PEC is less than 70% and therefore the impact can be described as ‘not significant’.

Riverside Energy Park Dispersion Modelling Report

Annual mean cadmium

8.4.9 As shown in Appendix B.10, the maximum annual mean cadmium process contribution is predicted to be 5.1% of the AQAL. However, this assumes that the entire cadmium and thallium emissions consist of only cadmium for screening purposes. Monitoring from similar facilities has shown that typically emissions of cadmium are 14% of the IED ELV (or 0.007 mg/Nm3), which equates to 35% of the BAT AEL being applied for. Table 8-1 provides a summary of the point of maximum impact for the following scenarios:

 Screening – assumes cadmium is released at 100% of the combined BAT AEL;

 Worst-case – assumes cadmium is released at 50% of the combined BAT AEL; and

 Typical – assumes cadmium is released at 35% of the combined BAT AEL.

Table 8-1: Annual Mean Cadmium Analysis

Scenario PC (ng/m3) PC (as % of AQAL)

Screening 0.25 5.1%

Worst-case 0.13 2.5%

Typical 0.09 1.8%

8.4.10 The contour plot is provided in Appendix A.11 for the typical emissions scenario. The peak impact is predicted to occur within the River Thames. This is not considered to be an area of relevant exposure associated with the annual mean AQAL.

8.4.11 Detailed results at the identified sensitive receptors are provided in Appendix B.10. As shown, at all receptor locations assuming the emissions of cadmium would be no greater than a typical plant, the impact can be screened out as ‘insignificant’.

Metals analysis

8.4.12 The EA document ‘Guidance to Applicants on Impact Assessment for Group 3 Metals Stack Releases – V.4 June 2016’ (“Metals Guidance”) outlines a two-stage assessment methodology for detailed modelling of Group 3 metals. The Metals Guidance states that where the process contribution for any metal exceeds 1% of the long-term or 10% of the short-term environmental standard (in this case the AQAL), this is considered to have potential for significant pollution. Where the process contribution exceeds these criteria, the PEC should be compared to the environmental standard. The impact can be screened out as ‘not significant’ where the PEC is less than the environmental standard.

8.4.13 Appendix B.3 (Long-term) and B.4 (Short Term) present the maximum modelled process contribution from the ERF and PEC assuming that each metal is released at the combined metal BAT AEL (i.e. 0.3 mg/m3), as required in step one of the Metals Guidance. Further analysis has also been undertaken assuming the release from the ERF is no greater than the maximum monitored at an existing waste facility, as required in step two of the Metals Guidance. Process contributions which are greater than 1% of the long-term AQAL or 10% of the short-term AQAL are highlighted.

Riverside Energy Park Dispersion Modelling Report

8.4.14 As shown in Appendix B.3 (Long-term), if it is assumed that the entire emissions of metals consist of only one metal, the annual process contributions from the ERF of arsenic, chromium (VI), lead, manganese and nickel are predicted to be greater than 1% of the long-term AQAL at the point of maximum impact. However, only the PECs for arsenic and chromium (VI) are predicted to be greater than 100% of the AQAL under this worst-case screening assumption.

8.4.15 If it is assumed that the ERF will perform no worse than a currently operating facility, the predicted process contribution is below 1% of the AQAL for all pollutants with the exception of arsenic and nickel. However, the PECs for arsenic and nickel are well below 100% of the AQAL, and so the impacts can be screened out. Therefore, using the ‘Metals Guidance’, it can be concluded that there is no risk of exceeding the short-term AQAL for any metal and there is no potential for significant pollution.

8.4.16 As shown Appendix B.4 (Short Term), if it is assumed that the entire emissions of metals consist of only one metal, the maximum 1-hour process contributions of all metals from the ERF is predicted to be less than 10% of the short-term AQAL at the point of maximum impact. Therefore, using the EA guidance criteria, it can be concluded that there is no risk of exceeding the short-term AQAL for any metal and there is no potential for significant pollution.

8.5 Biogas engine only

8.5.1 The detailed results tables are provided in Appendix B.5. The contribution from the biogas engine operating in isolation with the proposed 8m high stack cannot be screened out as ‘insignificant’ for all pollutants and averaging periods, i.e. for:

 Annual mean NO2 impacts;

 Short term NO2 impacts;

 Short term SO2 impacts.

8.5.2 Further analysis of the above pollutants and averaging periods has been undertaken in paragraphs 8.5.3 to 8.5.7.

Annual mean NO2

8.5.3 As shown in Appendix B.5, the maximum annual mean nitrogen dioxide process contribution is predicted to be 66.7% of the AQAL. The contour plot is provided in Appendix A.17. The peak impact is predicted to occur within the Installation Boundary. Impacts greater than 1% of the AQAL are limited to an area within approximately 350 m of the Installation Boundary. There are no areas of relevant exposure associated with the annual mean AQAL within 350 m of the Installation Boundary and therefore the impact can be screened out as ‘insignificant’ at all areas of relevant exposure.

th 99.79 percentile of hourly mean NO2

8.5.4 As shown in Appendix B, the maximum 99.79th percentile of hourly mean nitrogen dioxide process contribution is predicted to be 79.8% of the AQAL. The contour plot is provided in Appendix A.18. The peak impact is predicted to occur within the Installation Boundary. Impacts greater than 10% of the AQAL are limited to an area within approximately 70 m of the Installation Boundary. The impacts do not occur in an area where the public would reasonably be expected to spend an hour or longer, and therefore are not areas of relevant exposure associated with the hourly mean AQAL. The impact at all areas of relevant exposure can be screened out as ‘insignificant’.

Riverside Energy Park Dispersion Modelling Report

th 99.18 percentile of daily mean SO2

8.5.5 As shown in Appendix B, the maximum 99.18th percentile of daily sulphur dioxide process contribution is predicted to be 34.1% of the AQAL. The contour plot is provided in Appendix A.19. The peak impact is predicted to occur within the Installation Boundary. Impacts greater than 10% of the AQAL are limited to an area within approximately 50 m of the Installation Boundary. The impacts do not occur in an area where the public would reasonably be expected to spend up to a day, and therefore the impact at all areas of relevant exposure can be screened out as ‘insignificant’.

rd 99.73 percentile of hourly mean SO2

8.5.6 As shown in Appendix B, the maximum 99.73rd percentile of hourly sulphur dioxide process contribution is predicted to be 27.1% of the AQAL. The contour plot is provided in Appendix A.20. The peak impact is predicted to occur within the Installation Boundary. Impacts greater than 10% of the AQAL are limited to an area within approximately 50 m of the Installation Boundary. The impacts do not occur in an area where the public would reasonably be expected to spend an hour or longer, and therefore the impact at all areas of relevant exposure can be screened out as ‘insignificant’.

th 99.9 percentile of 15-minute mean SO2

8.5.7 As shown in Appendix B, the maximum 99.9th percentile of 15-minute mean sulphur dioxide process contribution is predicted to be 38.4% of the AQAL. The contour plot is provided in Appendix A.21. The peak impact is predicted to occur within the Installation Boundary. Impacts greater than 10% of the AQAL are limited to an area within approximately 60 m of the Installation Boundary. The impacts do not occur in an area where the public would reasonably be expected to spend fifteen minutes or longer, and therefore the impact at all areas of relevant exposure can be screened out as ‘insignificant’.

8.6 Combined operation of ERF and biogas engine

8.6.1 The biogas engine stack would be 8 m high, which would result in impacts occurring very close to the stack. As shown in Appendix B.6, the results for the point of maximum impact for the biogas engine only and for the combined impact of the ERF are the same. This is because the maximum impact from the biogas engine occurs very close to the biogas engine stack, where the impact from the ERF is insignificant.

8.6.2 Annual mean impacts from the biogas engine that do not screen out as ‘insignificant’, in accordance with the Air Emission Guidance, extend approximately 350 m from the stack, and short-term impacts that do not screen out as ‘insignificant’ extend approximately 70 m from the stack. The impacts from the ERF occur much further from REP, with the annual mean impacts that do not screen out as ‘insignificant’ occurring approximately 570 m from the stack at the closest point. All short-term impacts from the ERF screen out as ‘insignificant’. Therefore, it is considered that there is no potential for in-combination impacts from the concurrent operation of the ERF and biogas engine.

Riverside Energy Park Dispersion Modelling Report

9 Impact at Ecological Receptors

9.1.1 This section provides an assessment of the impact of emissions at the ecological receptors identified in Section 5.2.

9.2 Screening

9.2.1 The EA has produced Operational Instruction documents which explain how to assess aerial emissions from new or expanding Integrated Pollution Prevention and Control (IPPC) regulated industry applications, issued under the Environmental Permitting Regulations. These documents also outline the process to follow to satisfy the requirements of the Conservation of Habitats and Species Regulations 2010, Countryside and Rights of Way (CRoW) Act 2000, and the EA’s wider duties under the Environment Act 1995 and the Natural Environment and Rural Communities Act 2006 (NERC06).

9.2.2 Operational Instruction 67_12 ‘Detailed assessment of the impact of aerial emissions from new or expanding IPPC regulated industry for impacts on nature conservation’ provides the risk-based screening criteria set out in Table 9-1 for nature conservation sites, where:

 Y is the long-term process contribution calculated as a percentage of the relevant Critical Level or Load; and

 Z is the long-term predicted environmental concentration (PEC) calculated as a percentage of the relevant Critical Level or Load.

Table 9-1: Screening Criteria

NNR, LNR, LWS, Threshold European Sites SSSIs ancient woodland Y (% threshold long-term) 1 1 100 Y (% threshold short-term) 10 10 100 Z (% threshold) 70 70 100 Note: Short-term considers both daily and weekly timescales.

9.2.3 Operational Instruction 67_12 states:

 If process contribution < Y% Critical Level and Load then emissions from the application are ‘not significant’; and

 If PEC < Z% Critical Level and Load it can be concluded ‘no likely significant effect’ (alone and in-combination).

9.2.4 AQTAG 17 – ‘Guidance on in combination assessments for aerial emissions from EPR permits’ states that:

“Where the maximum process contribution (PC) at the European site(s) is less than the Stage 2 de-minimis threshold of the relevant critical level or load, the PC is considered to be inconsequential and there is no potential for an alone or in-combination effects with other plans and projects.”

Riverside Energy Park Dispersion Modelling Report

9.3 Atmospheric emissions - Critical Levels

9.3.1 In addition to the objectives for the protection of human health, the AQS includes Critical Levels for the protection of ecosystems as presented in Table 3-3. The predicted contribution from the REP have been compared to these Critical Levels.

9.3.2 Where the emissions of a particular pollutant are greater than 1% of the long-term or 10% of the short-term Critical Level at a statutory receptor, further assessment has been undertaken. At the non-statutory designated sites, further assessment is required only where concentrations of a particular pollutant exceed the long-term or short-term Critical Level.

9.3.3 For the purpose of the ecological assessment, the mapped background dataset from APIS has been used. If the process contribution is more than 1% of the long-term or 10% of the short-term Critical Level further consideration will be made to the baseline concentration.

9.4 Deposition of emissions – Critical Loads

9.4.1 APIS provides Critical Loads for nature conservation sites at risk from acidification and nitrogen deposition (eutrophication). Site-specific data is available for European and UK designated sites, and so an assessment has been made for these habitat features in APIS. Site-specific data is not available for non-designated sites. In lieu of this, the search by location function of APIS has been used to determine the appropriate Critical Loads to be used.

9.4.2 For each receptor, the grid reference for the point closest to REP has been input to represent the point of maximum impact at each site. These are the same receptor locations used in the DCO application. The resulting Critical Loads from each location are representative for each relevant broad habitat type.

9.4.3 Where the impact of process emissions from REP upon nitrogen or acid deposition is greater than 1% of the Critical Load at statutory designated sites, further assessment has been undertaken. At the non-statutory designated sites, further assessment is required only where the process emissions exceed the Critical Load.

9.4.4 For the purpose of the ecological assessment, the mapped background dataset from APIS has been used. If the process contribution is more than 1% of the Critical Load further consideration will be made to the baseline concentration.

Nitrogen deposition – eutrophication

9.4.5 Appendix C.1 and C.2 summarise the Critical Loads for nitrogen deposition and background deposition rates as detailed in APIS for each identified receptor. The lowest Critical Loads for each designated site have been used to ensure a robust assessment. The impact has been assessed against these Critical Loads for nitrogen deposition.

Acidification

9.4.6 The APIS Database contains a maximum critical load for sulphur (CLmaxS), a minimum critical load for nitrogen (CLminN) and a maximum critical load for nitrogen (CLmaxN). These components define the Critical Load function. Where the acid deposition flux falls within the area under the Critical Load function, no exceedances are predicted.

9.4.7 A search has been undertaken for each of the ecological receptors identified. Each site contains a number of habitat types, each with different Critical Loads. Appendix C.1 and C.2 summarise the Critical Loads for acidification and background deposition rates as detailed in APIS for each identified habitat. The lowest Critical Loads for each designated site have been used to ensure a robust assessment. The impact has been assessed against these Critical

Riverside Energy Park Dispersion Modelling Report

Load functions. Where a critical load function for acid deposition is not available, the total nitrogen and sulphur deposition has been presented and compared with the background concentration.

Calculation methodology – nitrogen deposition

9.4.8 The impact of deposition has been assessed using the methodology detailed within the Habitats Directive AQTAG 6 (March 2014). The steps to this method are as follows.

a. Determine the annual mean ground level concentrations of nitrogen dioxide and ammonia at each site.

b. Calculate the dry deposition flux (µg/m2/s) at each site by multiplying the annual mean ground level concentration by the relevant deposition velocity presented in Table 9-2.

c. Convert the dry deposition flux into units of kgN/ha/yr using the conversion factors presented in Table 9-2.

d. Compare this result to the nitrogen deposition Critical Load.

Table 9-2: Deposition Factors

Deposition Velocity (m/s) Conversion Factor Pollutant (µg/m2/s to Grassland Woodland kg/ha/year) Nitrogen dioxide 0.0015 0.003 96.0 Sulphur dioxide 0.0120 0.024 157.7 Ammonia 0.0200 0.030 259.7 Hydrogen chloride 0.0250 0.060 306.7

Acidification

9.4.9 Deposition of nitrogen, sulphur, hydrogen chloride and ammonia can cause acidification and should be taken into consideration when assessing the impact of REP.

9.4.10 The steps to determine the acid deposition flux are as follows.

a. Determine the dry deposition rate in kg/ha/yr of nitrogen, sulphur, hydrogen chloride and ammonia using the values outlined in Table 9-2.

b. Apply the conversion factor for nitrogen outlined in Table 9-3 to the nitrogen and ammonia deposition rate in kg/ha/year to determine the total keq/ha/year.

c. Apply the conversion factor for sulphur to the sulphur deposition rate in kg/ha/year to determine the total keq/ha/year.

d. Apply the conversion factor for HCl to the hydrogen chloride deposition rate in kg/ha/year to determine the dry keq/ha/year.

e. Determine the wet deposition rate of HCl in kg/ha/yr by multiplying the model output by the factors presented in Table 9-3.

Riverside Energy Park Dispersion Modelling Report

f. Apply the conversion factor for HCl to the hydrogen chloride deposition rate in kg/ha/year to determine the wet keq/ha/year.

g. Add the contribution from S to HCl dry and wet and treat this sum as the total contribution from S.

h. Plot the results against the Critical Load functions.

9.4.11 The March 2014 version of the AQTAG 6 document states that, for installations with a hydrogen chloride emission, the PC of hydrogen chloride, in addition to sulphur and nitrogen, should be considered in the acidity Critical Load assessment. The H+ from hydrogen chloride should be added to the sulphur contribution (and treated as sulphur in the APIS tool). This should include the contribution of hydrogen chloride from wet deposition.

9.4.12 For the purpose of this analysis it has been assumed that wet deposition of hydrogen chloride is double dry deposition.

Table 9-3: Conversion Factors

Pollutant Conversion Factor (kg/ha/year to keq/ha/year) Nitrogen Divide by 14 Sulphur Divide by 16 Hydrogen chloride Divide by 35.5

9.4.13 The contribution from the Facility has been calculated using the APIS formula:

 Where PEC N Deposition < CLminN:

• PC as % of CL function = PC S deposition / CLmaxS

 Where PEC N Deposition > CLminN:

• PC as % of CL function = (PC S + N deposition) / CLmaxN

9.5 Results – atmospheric emissions – Critical Levels

9.5.1 As noted in Section 8.6 the contribution from the biogas engine is restricted to the area close to REP. Therefore, this analysis has focussed on the impact of emissions from the ERF. The results have been compared to the Critical Levels listed in Table 3.3. In accordance with the stated assessment methodology, where the process contribution of a particular pollutant at a European or UK designated site is greater than 1% of the long term or 10% of the short-term Critical Level, or greater than 100% of the Critical Level at a non-statutory designated site, further assessment would be undertaken. The process contribution has been calculated based on the maximum predicted using all 5-years of weather data. These results are presented in Appendix D.1.

9.5.2 As shown in Appendix D.1, at all statutory designated sites, the process contribution is less than 1% of the long term and less than 10% of the short term Critical Level for all pollutants considered with the exception of impacts at Inner Thames Marshes and Ingrebourne Marshes and the impact can be screened out as ‘not significant’. Further analysis has been undertaken of the impact at these sites in the following section.

9.5.3 At all non-statutory designated sites, the process contribution is less than 100% of the Critical Level for all pollutants considered, and the impact can be screened out as ‘not significant’.

Riverside Energy Park Dispersion Modelling Report

9.6 Results – atmospheric emissions – Critical Loads

9.6.1 This analysis has only focussed on the impact of emissions from the ERF. The results have been compared to the habitat specific Critical Loads listed in Appendix C.1 and C.2. In accordance with the stated assessment methodology, where the process contribution of a particular pollutant at a European or UK designated site is greater than 1% of the Critical Load, or greater than 100% of the Critical Load at a non-statutory designated site, further assessment would be undertaken. The process contribution has been calculated based on the maximum predicted using all 5-years of weather data. These results are presented in Appendix D.2 and D.3.

9.6.2 As shown in Appendix D.2 and D.3, at all statutory designated sites the process contribution is less than 1% of the habitat specific Critical Load, with the exception of impacts at Ingrebourne Marshes, and the impact can be screened out as ‘not significant’. Further analysis has been undertaken of the impact at Ingrebourne Marshes in the following section.

9.6.3 At all non-statutory designated sites the process contribution is less than 100% of the habitat specific Critical Load, and the impact can be screened out as ‘not significant’.

9.7 Results – further analysis at Inner Thames Marshes SSSI

9.7.1 Inner Thames Marshes is designated as a SSSI and is located predominantly to the east of REP, but the closest area of the Inner Thames Marshes is located to the north-east, on the opposite bank of the River Thames. This is designated as it is the largest remaining wetland bordering the upper reaches of the Thames Estuary. As this site is located in close proximity to REP, it is appropriate to consider all modelled grid points across the designated sites.

9.7.2 Table 9-4 presents the results of the peak concentration as a percentage of the relevant Critical Level across the SSSI from all modelled points within the SSSI.

Table 9-4: Impact Analysis at Inner Thames Marshes SSSI

Pollutant and averaging period Process Contribution (as % of CL)

Annual mean - oxides of nitrogen 1.7%

Annual mean - sulphur dioxide 1.0%

Annual mean – ammonia 2.2%

Maximum daily – oxides of nitrogen 3.7%

Maximum daily – hydrogen fluoride 0.7%

Maximum weekly – hydrogen fluoride 4.9%

N deposition 1.9%

Acid deposition – no comparable CL in APIS -

9.7.3 As shown, the maximum annual mean oxides of nitrogen and ammonia process contributions and N deposition rate slightly exceed the 1% screening criteria.

Riverside Energy Park Dispersion Modelling Report

9.7.4 APIS states that the maximum background oxides of nitrogen concentration over the SSSI is 35.4µg/m3 which exceeds the Critical Level of 30 µg/m3. Therefore, it cannot be concluded that emissions are not significant using the EA screening criteria as the PEC exceeds 70% of the Critical Level.

9.7.5 The maximum background ammonia concentration from APIS over the SSSI is 2.4µg/m3 which is only 80% of the Critical Level. The additional contribution from REP would increase concentrations by a maximum of 2.2% of the Critical Level. Therefore, although the overall PEC would remain below the Critical Level it would be greater than 70%. Therefore, it cannot be concluded that emissions are not significant using the EA screening criteria.

9.7.6 As detailed in Chapter 11 of the Environmental Statement (ES) for the DCO application, annual mean Critical Levels are primarily related to the potential for impacts of nutrient nitrogen deposition. The maximum background N deposition rate over the SSSI from APIS is 16.94 kgN/ha/yr which is greater than 70% of the Critical Load of 20 kgN/ha/yr for saltmarsh habitats and therefore the impact cannot be considered ‘not significant’ using EA guidance.

9.7.7 However, a review of the SSSI units (https://designatedsites.naturalengland.org.uk) where the nitrogen deposition impact is greater than 1% of the Critical Load (units 1, 10 and 11) shows that unit 10 has been destroyed by the construction of the A13, and units 1 and 11 consist of neutral grassland habitat and are in ‘unfavourable – recovering’ condition. The only habitat within the SSSI for which an N deposition Critical Load is provided on APIS is ‘pioneer, low- mid, mid-upper saltmarshes’. This is not the main habitat in units 1 and 11 of the SSSI, i.e., the units where the N deposition process contribution cannot be screened out as ‘insignificant’. Therefore, these impacts do not occur on a sensitive habitat for which the SSSI has been designated and for which a Critical Load is defined on APIS. As such, the integrity of the SSSI is not likely to be compromised by the small additional contribution from REP.

9.8 Results – further analysis at Ingrebourne Marshes SSSI

9.8.1 Ingrebourne Marshes is designated as a SSSI and is located to the northeast of REP on the opposite site of the River Thames. This is designated as one of the most diverse areas of freshwater marshland in Greater London. As this site is located in relatively close proximity to REP, it is appropriate to consider all modelled grid points across the designated sites.

9.8.2 Table 9-5 presents the results of the peak concentration as a percentage of the relevant Critical Load from all modelled points within the SSSI.

Table 9-5 Impact Analysis at Ingrebourne Marshes SSSI

Pollutant and averaging period Process Contribution (as % of CL)

Annual mean - oxides of nitrogen 1.1%

Annual mean - sulphur dioxide 0.6%

Annual mean – ammonia 1.4%

Maximum daily – oxides of nitrogen 2.0%

Maximum daily – hydrogen fluoride 0.4%

Maximum weekly – hydrogen fluoride 2.2%

Riverside Energy Park Dispersion Modelling Report

Pollutant and averaging period Process Contribution (as % of CL)

N deposition 1.7%

Acid deposition – not sensitive -

9.8.3 As shown, the maximum annual mean oxides of nitrogen and ammonia process contributions and N deposition rate slightly exceed the 1% screening criteria.

9.8.4 APIS states that the maximum background oxides of nitrogen concentration over the SSSI is 29.9µg/m3 which is just below the Critical Level of 30 µg/m3. Therefore, it cannot be concluded that emissions are not significant using the EA screening criteria as the PEC exceeds 70% of the Critical Level.

9.8.5 The maximum background ammonia concentration from APIS over the SSSI is 2.4µg/m3 which is only 80% of the Critical Level. The additional contribution from REP would increase concentrations by a maximum of 1.4% of the Critical Level. Therefore, although the overall PEC would remain below the Critical Level it would be greater than 70%. Therefore, it cannot be concluded that emissions are not significant using the EA screening criteria.

9.8.6 The maximum background N deposition rate over the SSSI from APIS is 16.94 kgN/ha/yr which exceeds the lower Critical Load of 15 kgN/ha/yr for fen habitats, and therefore the impact cannot be considered ‘not significant’ using EA guidance. However, as shown in Appendix D.2 the process contribution is less than 1% of the upper Critical Load.

9.8.7 A review of the SSSI units (https://designatedsites.naturalengland.org.uk) where the nitrogen deposition impact is greater than 1% of the lower Critical Load (units 1, 3, 5, 6, 8, 9, 10 and 11) shows that all units are in ‘favourable’ condition with the exception of units 1, 6 and 9. Units 1 and 6 are in ‘unfavourable – declining’ condition and unit 9 is in ‘unfavourable – no change’ condition. Where the unit condition is described as favourable, the small additional contribution from REP is not likely to affect the integrity of the SSSI. Natural England provides additional information under ‘Comment’/’Adverse Condition Reason’ for each of the units in unfavourable condition. This information shows that the unfavourable conditions are due to ‘dense litter cover’ and ‘agriculture – inappropriate cutting and mowing’ along with ‘invasive species’ and ‘negative indicator species’. Therefore, the unfavourable conditions are not due to nitrogen deposition from atmospheric pollutants or from agricultural runoff but are instead due to other unrelated issues. As such, the integrity of the SSSI is not likely to be compromised by the small additional contribution from REP.

9.9 Results - Biogas engine

9.9.1 As noted in Section 8.6, the contribution from the biogas engine is restricted to the area very close to REP. The Crossness LNR lies adjacent to REP, and therefore the impact on this ecological receptor has been considered. This analysis has been undertaken using plot files which show the process contribution from the biogas engine. The following plot files have been produced and are presented in Appendix A as follows:

 A.22: Annual Mean NOx as % of Critical Level (Biogas engine only);

 A.23: Max 24hr NOx as % of Critical Level (Biogas engine only);

 A.24: Annual Mean SO2 as % of Critical Level (Biogas engine only);

Riverside Energy Park Dispersion Modelling Report

 A.25: Annual Mean Nitrogen Deposition as % of Critical Load (Biogas engine only); and

 A.26: Annual Mean Acid Deposition as % of Critical Load (Biogas engine only).

9.9.2 A review of these plot files shows that the process contribution for all pollutants and averaging periods is less than 100% of the Critical Level or Load within the Crossness LNR, with the exception of maximum 24 hour NOx. Therefore, the impact of the biogas engine can be screened out as ‘insignificant’ for all pollutants and averaging periods with the exception of maximum 24 hour NOx.

9.9.3 The plot file of maximum 24 hour NOx (Appendix A.23) shows that the process contribution exceeds the Critical Level across a section of the Crossness LNR close to REP, and exceeds 200% of the Critical Level across a small section of the LNR closest to the biogas engine. The significance of this impact has been considered in Chapter 11 of the ES for the DCO application. In paragraph 11.9.25 of the ES it was concluded that:

“The contour plots indicate that the effects of the anaerobic digestion [biogas engine] emissions are limited to the immediate vicinity of the REP site and are not cumulative with the emissions from the ERF… this could result in changes to the habitats through an increase in dominant grass species with a subsequent reduction in broadleaved species. However older marshes, such as this, are less sensitive to nitrogen deposition than new or evolving habitats (apis.ac.uk, 2018) and the areas of the LNR/SINC affected are limited to marginal habitats in the immediate vicinity of the REP site. Habitats likely to be affected are not of high botanical diversity consisting of tall ruderal, semi-improved grassland, and scrub. Therefore, predicted effects through nitrogen deposition to these designated areas of County/Metropolitan conservation importance are Not Significant.”

9.9.4 It is therefore considered that the operation of the biogas engine will not have an unacceptable impact on the Crossness LNR.

9.10 Results - Combined operation of ERF and biogas engine

9.10.1 As detailed in Section 8.6, the impacts from the biogas engine and the ERF occur in different areas and it is considered that there is no potential for in-combination impacts from the concurrent operation of the ERF and biogas engine.

Riverside Energy Park Dispersion Modelling Report

10 Conclusions

10.1.1 This Dispersion Modelling Assessment has been undertaken to support the EP application for REP. The dispersion modelling has been based on the assumption that the ERF would operate continually at the maximum design capacity with 100% availability, together with the contribution from the biogas engine.

10.1.2 This assessment has included a review of baseline pollution levels, dispersion modelling of emissions and quantification of the impact of these emissions on local air quality. A stack height analysis has been undertaken considering both the Rochdale Envelope building design and the realistic stepped building. A detailed assessment of the impact of REP has then been undertaken using the more realistic stepped building. This has drawn on the modelling carried out for the DCO application. However, some refinements have been made such as the model domain extents to ensure that this is fit for the purpose of the EP application.

10.1.3 The primary conclusions of the assessment are presented below.

 The peak concentration predicted is greater with the Rochdale Envelope than with the more realistic stepped building design, however, away from this peak the predicted concentration is similar for the two scenarios.

 In relation to the impact on human health:

• Emissions from the operation of REP will not cause a breach of any AQAL.

• At all sensitive receptors the impact of emissions is described as ‘not significant’. For most pollutants the impact can be described as ‘insignificant’.

• There is no risk of exceeding an AQAL for heavy metals.

 In relation to the impact on ecologically sensitive sites:

• At all of the statutory designated sites the impact of process emissions from REP can be screened out as ‘not significant’, with the exception of the Inner Thames Marshes and Ingrebourne Marshes SSSIs. As detailed in paragraph 9.7.6, annual mean NOx and ammonia Critical Levels are primarily related to the potential for impacts of nutrient nitrogen deposition. As such, further analysis has focussed on N deposition impacts.

• At Inner Thames Marshes SSSI, although the process contribution exceeds 1% of the Critical Level for annual mean NOx and ammonia and 1% of the Critical Load for N deposition, the only habitat listed on APIS for this SSSI for which an N deposition Critical Load is provided is ‘pioneer, low-mid, mid-upper saltmarshes’. This is not the main habitat in the parts of the SSSI where the N deposition process contribution cannot be screened out as ‘insignificant’. Therefore, these impacts do not occur on a sensitive habitat for which the SSSI has been designated and for which a Critical Load is defined on APIS. As such, the integrity of the SSSI is not likely to be compromised by the small additional contribution from REP.

• At Ingrebourne Marshes SSSI, the process contribution exceeds 1% of the Critical Level for annual mean NOx and ammonia and 1% of the lower Critical Load for N deposition. However, the process contribution does not exceed 1% of the upper Critical Load for N deposition. A review of the unit conditions provided by Natural England shows that all but three of the units where impacts exceed 1% of the lower Critical Load are in favourable condition, and the small additional contribution from REP is not likely to affect the integrity of these units. For the three units in

Riverside Energy Park Dispersion Modelling Report

unfavourable condition, Natural England’s comments indicate that the unfavourable conditions are due to external factors which are not linked to nitrogen deposition and therefore the integrity of the SSSI is not likely to be compromised by the small additional contribution from REP.

• At all non-statutory designated sites, the impact of process emissions from REP can be screened out as ‘not significant’, with the exception of the impact of the biogas engine at Crossness LNR.

• At Crossness LNR the maximum 24 hour NOx process contribution exceeds the Critical Level. However, the habitat type (older, well-established marshland) is less sensitive to nitrogen deposition than new or evolving habitats and the affected areas are limited to marginal habitats in the immediate vicinity of Installation Boundary. Habitats likely to be affected are not of high botanical diversity consisting of tall ruderal, semi-improved grassland, and scrub. Therefore, the unfavourable conditions are not due to nitrogen deposition from atmospheric pollutants or from agricultural runoff but are instead due to other unrelated issues. As such, the integrity of the SSSI is not likely to be compromised by the small additional contribution from REP.

10.1.4 In summary, the assessment of the proposed operation of REP has shown that emissions would not have a significant impact on local air quality, the general population or the local community or sensitive ecological features. As such there should be no air quality constraint in granting an EP to operate REP.

Riverside Energy Park Dispersion Modelling Report

Appendix A Figures

A.1 Human Sensitive Receptors

Riverside Energy Park Dispersion Modelling Report

A.2 Ecological Sensitive Receptors - 2km Buffer

Riverside Energy Park Dispersion Modelling Report

A.3 Ecological Sensitive Receptors - 15km Buffer

Riverside Energy Park Dispersion Modelling Report

A.4 Wind Roses - London City Airport

Riverside Energy Park Dispersion Modelling Report

A.5 Modelling Domain _ERF

Riverside Energy Park Dispersion Modelling Report

A.6 Modelling Domain – Biogas Engine

Riverside Energy Park Dispersion Modelling Report

A.7 Buildings

Riverside Energy Park Dispersion Modelling Report

A.8 Annual mean Nitrogen Dioxide Analysis - Stepped & Rochdale Envelope

Riverside Energy Park Dispersion Modelling Report

A.9 Annual mean VOCs Analysis - as Benzene - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.10 Annual mean VOCs Analysis - as 1,3-Butadiene - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.11 Annual mean Cadmium Analysis - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.12 Annual mean Oxides of Nitrogen - % of Critical Level (30 µg/m³)

Riverside Energy Park Dispersion Modelling Report

A.13 Annual mean Sulphur Dioxide - % of Critical Level (20 µg/m³)

Riverside Energy Park Dispersion Modelling Report

A.14 Annual mean Ammonia - % of Critical Level (3 µg/m³)

Riverside Energy Park Dispersion Modelling Report

A.15 Annual mean Nitrogen Deposition - % of Critical Load of 15 kgN/ha/yr

Riverside Energy Park Dispersion Modelling Report

A.16 Annual mean Nitrogen Deposition - % of CL (20 kgN/ha/yr)

Riverside Energy Park Dispersion Modelling Report

A.17 Biogas Engine Annual Mean Nitrogen Dioxide - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.18 Biogas Engine 99.79th %ile of Hourly Mean Nitrogen Dioxide - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.19 Biogas Engine 99.18th %ile of 24hr Sulphur Dioxide - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.20 Biogas Engine 99.73rd %ile of Hourly Mean Sulphur Dioxide - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.21 Biogas Engine 99.9th %ile of 15min Sulphur Dioxide - % of AQAL

Riverside Energy Park Dispersion Modelling Report

A.22 Biogas Engine Annual Mean Oxides of Nitrogen - % of CL

Riverside Energy Park Dispersion Modelling Report

A.23 Biogas Engine Maximum Daily Oxides of Nitrogen - % of CL

Riverside Energy Park Dispersion Modelling Report

A.24 Biogas Engine Annual Mean Sulphur Dioxide - % of CL

Riverside Energy Park Dispersion Modelling Report

A.25 Biogas Engine Nitrogen Deposition - % of Critical Load

Riverside Energy Park Dispersion Modelling Report

A.26 Biogas Engine Acid Deposition - % of CL

Riverside Energy Park Dispersion Modelling Report

Appendix B Detailed Results Tables

Riverside Energy Park Dispersion Modelling Report

B.1 Point of Maximum Impact Detailed Results – ERF Only – Daily ELV

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

Annual mean µg/m3 40 16.6 0.40 0.48 0.59 0.54 0.66 0.66 1.7% 17.3 43.2% Nitrogen dioxide 99.79th %ile of µg/m3 200 33.2 2.72 2.77 2.70 2.71 2.66 2.77 1.4% 36.0 18.0% hourly means

99.18th %ile of µg/m3 125 4.0 1.70 1.93 1.96 1.89 1.85 1.96 1.6% 6.0 4.8% daily means

99.73rd %ile of µg/m3 Sulphur dioxide 350 4.0 3.08 3.12 3.07 3.06 3.00 3.12 0.9% 7.1 2.0% hourly means

99.9th %ile of 15 µg/m3 266 4.0 3.63 3.62 3.63 3.52 3.45 3.63 1.4% 7.6 2.9% min. means

Annual mean µg/m3 40 14.5 0.04 0.05 0.06 0.05 0.06 0.06 0.2% 14.6 36.4% Particulates (PM10) 90.4th %ile of daily µg/m3 50 29.0 0.13 0.16 0.17 0.17 0.19 0.19 0.4% 29.2 58.4% means

Particulates µg/m3 Annual mean 25 9.7 0.04 0.05 0.06 0.05 0.06 0.06 0.3% 9.8 39.1% (PM2.5)

8 hour running µg/m3 Carbon monoxide 10000 1.0 6.35 6.31 5.86 4.78 4.51 6.35 0.06% 7.3 0.1% mean

Riverside Energy Park Dispersion Modelling Report

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

Hydrogen chloride Hourly mean µg/m3 750 2.0 0.97 1.05 1.13 1.17 0.99 1.17 0.2% 3.2 0.4%

Annual mean µg/m3 16 0.5 0.01 0.01 0.01 0.01 0.01 0.01 0.08% 0.5 3.2% Hydrogen fluoride Hourly mean µg/m3 160 1.0 0.16 0.17 0.19 0.19 0.17 0.19 0.12% 1.2 0.7%

Annual mean µg/m3 180 2.0 0.08 0.09 0.11 0.10 0.13 0.13 0.07% 2.1 1.2% Ammonia Hourly mean µg/m3 2500 4.0 1.61 1.74 1.89 1.94 1.66 1.94 0.08% 5.9 0.2%

Annual mean µg/m3 5 0.6 0.08 0.09 0.11 0.10 0.13 0.13 2.5% 0.7 14.5% VOCs (as benzene) Hourly mean µg/m3 190 1.2 1.61 1.74 1.89 1.94 1.66 1.94 1.0% 3.1 1.6%

VOCs (as 1,3- µg/m3 Annual mean 2.25 0.3 0.08 0.09 0.11 0.10 0.13 0.13 5.6% 0.4 19.0% butadiene)

Annual mean ng/m3 250 2.0 0.15 0.18 0.22 0.21 0.25 0.25 0.10% 2.3 0.9% Mercury Hourly mean ng/m3 7500 4.0 3.23 3.48 3.78 3.89 3.31 3.89 0.05% 7.9 0.1%

Annual mean ng/m3 5 0.3 0.15 0.18 0.22 0.21 0.25 0.25 5.1% 0.5 10.1% Cadmium Hourly mean ng/m3 - 0.5 3.23 3.48 3.78 3.89 3.31 3.89 - 4.4 -

PaHs Annual mean pg/m3 250 200.0 0.80 0.96 1.18 1.08 1.33 1.33 0.5% 201.3 80.5%

Riverside Energy Park Dispersion Modelling Report

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

Dioxins and Annual mean fg/m3 - 8.0 0.45 0.55 0.67 0.62 0.76 0.76 - 8.8 - Furans

Annual mean ng/m3 200 0.1 0.04 0.05 0.06 0.05 0.06 0.06 0.03% 0.2 0.1% PCBs Hourly mean ng/m3 6000 0.2 0.81 0.87 0.94 0.97 0.83 0.97 0.02% 1.2 0.02%

Riverside Energy Park Dispersion Modelling Report

B.2 Point of Maximum Impact Detailed Results – ERF Only – Short Term ELV

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

99.79th %ile of Nitrogen dioxide µg/m3 200 33.2 14.49 14.78 14.37 14.44 14.18 14.78 7.4% 48.0 24.0% hourly means

99.73rd %ile of µg/m3 350 4.0 20.52 20.83 20.46 20.42 20.01 20.83 6.0% 24.8 7.1% hourly means Sulphur dioxide 99.9th %ile of 15 µg/m3 266 4.0 20.52 20.83 20.46 20.42 20.01 20.83 7.8% 24.8 9.3% min. means

8 hour running µg/m3 Carbon monoxide 10000 1.0 12.70 12.62 11.71 9.57 9.01 12.70 0.1% 13.7 0.1% mean

Hydrogen chloride Hourly mean µg/m3 750 2.0 9.68 10.45 11.33 11.67 9.94 11.67 1.6% 13.7 1.8%

Hydrogen fluoride Hourly mean µg/m3 160 1.0 0.65 0.70 0.76 0.78 0.66 0.78 0.5% 1.8 1.1%

VOCs (as µg/m3 Hourly mean 190 1.2 3.23 3.48 3.78 3.89 3.31 3.89 2.0% 5.1 2.6% benzene)

Mercury Hourly mean ng/m3 7500 4.0 5.65 6.10 6.61 6.80 5.80 6.80 0.1% 10.8 0.1%

Riverside Energy Park Dispersion Modelling Report

B.3 Long-Term Metals Results – Point of Maximum Impact ERF Only – Metals Analysis

Metal AQAL Background Metals emitted at combined metal limit Metal as Metals emitted no worse than a currently permitted conc. % of facility (1) PC PEC ELV PC PEC ng/m³ ng/m³ ng/m³ as % AQAL ng/m³ as % ng/m³ as % AQAL ng/m³ as % AQAL AQAL Arsenic 3 1.00 3.80 126.66% 4.80 160.00% 8.3% 0.32 10.56% 1.32 43.89%

Antimony 5,000 1.00 3.80 0.08% 4.80 0.10% 3.8% 0.15 0.00% 1.15 0.02% Chromium 5,000 3.20 3.80 0.08% 7.00 0.14% 30.7% 1.17 0.02% 4.37 0.09% Chromium (VI) 0.2 0.64 3.80 1899.95% 4.44 2219.95% 0.043% 0.0016 0.82% 0.64 320.82% Cobalt - 0.10 3.80 - 3.90 - 1.9% 0.07 - 0.17 - Copper 10,000 11.00 3.80 0.04% 14.80 0.15% 9.7% 0.37 0.00% 11.37 0.11% Lead 250 11.00 3.80 1.52% 14.80 5.92% 16.8% 0.64 0.25% 11.64 4.65% Manganese 150 5.00 3.80 2.53% 8.80 5.87% 20.0% 0.76 0.51% 5.76 3.84% Nickel 20 1.00 3.80 19.00% 4.80 24.00% 73.3% 2.79 13.93% 3.79 18.93% Vanadium 5,000 1.00 3.80 0.08% 4.80 0.10% 2.0% 0.08 0.00% 1.08 0.02% Notes: (1) Metal as maximum percentage of the group 3 metals BAT AEL derived from monitored concentrations as detailed in EA metals guidance document (V.4) Table A1.

Riverside Energy Park Dispersion Modelling Report

B.4 Short-Term Metals Results – Point of Maximum Impact ERF Only – Metals Analysis

Metal AQAL Background Metals emitted at combined metal limit Metal as % Metals emitted no worse than a currently permitted conc. of ELV (1) facility PC PEC PC PEC ng/m³ ng/m³ ng/m³ as % AQAL ng/m³ as % AQAL ng/m³ as % AQAL ng/m³ as % AQAL Arsenic - 2.00 58.33 - 60.33 - 8.3% 4.86 - 6.86 -

Antimony 150,000 2.00 58.33 0.04% 60.33 0.04% 3.8% 2.24 0.001% 4.24 0.003% Chromium 150,000 6.40 58.33 0.04% 64.73 0.04% 30.7% 17.89 0.01% 24.29 0.02% Chromium (VI) - 1.28 58.33 - 59.61 - 0.043% 0.03 - 1.31 - Cobalt - 0.20 58.33 - 58.53 - 1.9% 1.09 - 1.29 - Copper 200,000 22.00 58.33 0.03% 80.33 0.04% 9.7% 5.64 0.003% 27.64 0.01% Lead - 22.00 58.33 - 80.33 - 16.8% 9.78 - 31.78 - Manganese 1,500,000 10.00 58.33 0.004% 68.33 0.005% 20.0% 11.67 0.001% 21.67 0.001% Nickel - 2.00 58.33 - 60.33 - 73.3% 42.77 - 44.77 - Vanadium 1,000 2.00 58.33 5.83% 60.33 6.03% 2.0% 1.17 0.12% 3.17 0.32% Notes: (1) Metal as maximum percentage of the group 3 metals BAT AEL derived from monitored concentrations as detailed in EA metals guidance document (V.4) Table A1

Riverside Energy Park Dispersion Modelling Report

B.5 Point of Maximum Impact Detailed Results – Biogas Engine Only

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

Annual mean µg/m3 40 16.6 26.7 23.9 22.7 24.8 20.3 26.7 66.7% 43.3 108.2% Nitrogen dioxide 99.79th %ile of µg/m3 200 33.2 157.4 159.7 151.8 158.2 156.2 159.7 79.8% 192.9 96.4% hourly means

99.18th %ile of µg/m3 125 4.0 40.3 42.7 35.2 35.2 36.8 42.7 34.1% 46.7 37.3% daily means

99.73rd %ile of µg/m3 Sulphur dioxide 350 4.0 89.4 94.9 88.6 92.0 91.4 94.9 27.1% 98.9 28.3% hourly means

99.9th %ile of 15 µg/m3 266 4.0 97.7 102.1 94.9 99.3 96.6 102.1 38.4% 106.1 39.9% min. means

Riverside Energy Park Dispersion Modelling Report

B.6 Point of Maximum Impact Detailed Results – ERF and Biogas Engine

Process Contribution (PC) Max PC Max PEC Averaging Bg Pollutant Units AQAL Period Conc. Max as Max as 2013 2014 2015 2016 2017 Conc. % of Conc. % of AQAL AQAL

Annual mean µg/m3 40 16.6 26.7 23.9 22.7 24.8 20.3 26.7 66.7% 43.3 108.2% Nitrogen dioxide 99.79th %ile of µg/m3 200 33.2 157.4 159.7 151.8 158.2 156.2 159.7 79.8% 192.9 96.4% hourly means

99.18th %ile of µg/m3 125 4.0 40.3 42.7 35.2 35.2 36.8 42.7 34.1% 46.7 37.3% daily means

99.73rd %ile of µg/m3 Sulphur dioxide 350 4.0 89.4 94.9 88.6 92.0 91.4 94.9 27.1% 98.9 28.3% hourly means

99.9th %ile of 15 µg/m3 266 4.0 97.7 102.1 94.9 99.3 96.6 102.1 38.4% 106.1 39.9% min. means

Riverside Energy Park Dispersion Modelling Report

B.7 Annual Mean Nitrogen Dioxide at Receptors

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R1 0.10 0.2% 16.70 41.7%

R2 0.09 0.2% 16.69 41.7%

R3 0.12 0.3% 16.72 41.8%

R4 0.06 0.2% 16.66 41.7%

R5 0.14 0.3% 16.74 41.8%

R6 0.16 0.4% 16.76 41.9%

R7 0.25 0.6% 16.85 42.1%

R8 0.26 0.7% 16.86 42.2%

R9 0.04 0.1% 16.64 41.6%

R10 0.03 0.1% 16.63 41.6%

R11 0.16 0.4% 16.76 41.9%

R12 0.04 0.1% 16.64 41.6%

R13 0.05 0.1% 16.65 41.6%

R14 0.04 0.1% 16.64 41.6%

R15 0.14 0.3% 16.74 41.8%

R16 0.10 0.3% 16.70 41.8%

R17 0.12 0.3% 16.72 41.8%

R18A 1st 0.26 0.6% 16.86 42.1%

R8B 0.26 0.7% 16.86 42.2%

R16B 0.10 0.2% 16.70 41.7%

R19A 1st 0.10 0.2% 16.70 41.7%

R19B 6th 0.10 0.3% 16.70 41.8%

R18B 4th 0.26 0.6% 16.86 42.1%

R20A GF 0.26 0.6% 16.86 42.1%

Riverside Energy Park Dispersion Modelling Report

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R20B 5th 0.26 0.6% 16.86 42.1%

R21 0.04 0.1% 16.64 41.6%

R23 0.06 0.1% 16.66 41.6%

R24 0.04 0.1% 16.64 41.6%

R25 0.04 0.1% 16.64 41.6%

R26 0.09 0.2% 16.69 41.7%

R27 0.02 0.1% 16.62 41.6%

R22 0.23 0.6% 16.83 42.1%

Riverside Energy Park Dispersion Modelling Report

B.8 Annual Mean VOC (as benzene) at Receptors

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R1 0.02 0.4% 0.62 12.4%

R2 0.02 0.3% 0.62 12.3%

R3 0.02 0.5% 0.62 12.5%

R4 0.01 0.2% 0.61 12.2%

R5 0.03 0.5% 0.63 12.5%

R6 0.03 0.6% 0.63 12.6%

R7 0.05 0.9% 0.65 12.9%

R8 0.05 1.0% 0.65 13.0%

R9 0.01 0.1% 0.61 12.1%

R10 0.01 0.1% 0.61 12.1%

R11 0.03 0.6% 0.63 12.6%

R12 0.01 0.2% 0.61 12.2%

R13 0.01 0.2% 0.61 12.2%

R14 0.01 0.2% 0.61 12.2%

R15 0.03 0.5% 0.63 12.5%

R16 0.02 0.4% 0.62 12.4%

R17 0.02 0.5% 0.62 12.5%

R18A 1st 0.05 1.0% 0.65 13.0%

R8B 0.05 1.0% 0.65 13.0%

R16B 0.02 0.4% 0.62 12.4%

R19A 1st 0.02 0.4% 0.62 12.4%

R19B 6th 0.02 0.4% 0.62 12.4%

R18B 4th 0.05 1.0% 0.65 13.0%

R20A GF 0.05 1.0% 0.65 13.0%

Riverside Energy Park Dispersion Modelling Report

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R20B 5th 0.05 1.0% 0.65 13.0%

R21 0.01 0.1% 0.61 12.1%

R23 0.01 0.2% 0.61 12.2%

R24 0.01 0.1% 0.61 12.1%

R25 0.01 0.1% 0.61 12.1%

R26 0.02 0.4% 0.62 12.4%

R27 <0.01 0.1% 0.60 12.1%

R22 0.04 0.9% 0.64 12.9%

Riverside Energy Park Dispersion Modelling Report

B.9 Annual Mean VOC (as 1,3-butadiene) at Receptors

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R1 0.02 0.8% 0.32 14.2%

R2 0.02 0.7% 0.32 14.1%

R3 0.02 1.0% 0.32 14.3%

R4 0.01 0.5% 0.31 13.9%

R5 0.03 1.2% 0.33 14.5%

R6 0.03 1.3% 0.33 14.6%

R7 0.05 2.1% 0.35 15.4%

R8 0.05 2.2% 0.35 15.6%

R9 0.01 0.3% 0.31 13.6%

R10 0.01 0.3% 0.31 13.6%

R11 0.03 1.4% 0.33 14.7%

R12 0.01 0.3% 0.31 13.7%

R13 0.01 0.4% 0.31 13.8%

R14 0.01 0.3% 0.31 13.7%

R15 0.03 1.2% 0.33 14.5%

R16 0.02 0.9% 0.32 14.2%

R17 0.02 1.0% 0.32 14.4%

R18A 1st 0.05 2.2% 0.35 15.5%

R8B 0.05 2.2% 0.35 15.5%

R16B 0.02 0.8% 0.32 14.2%

R19A 1st 0.02 0.8% 0.32 14.2%

R19B 6th 0.02 0.9% 0.32 14.2%

R18B 4th 0.05 2.2% 0.35 15.5%

R20A GF 0.05 2.2% 0.35 15.5%

Riverside Energy Park Dispersion Modelling Report

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R20B 5th 0.05 2.2% 0.35 15.5%

R21 0.01 0.3% 0.31 13.6%

R23 0.01 0.5% 0.31 13.8%

R24 0.01 0.3% 0.31 13.6%

R25 0.01 0.3% 0.31 13.6%

R26 0.02 0.8% 0.32 14.1%

R27 <0.01 0.2% 0.30 13.5%

R22 0.04 1.9% 0.34 15.3%

Riverside Energy Park Dispersion Modelling Report

B.10 Annual Mean Cadmium (Typical) at Receptors

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R1 0.01 0.3% 0.26 5.3%

R2 0.01 0.2% 0.26 5.2%

R3 0.02 0.3% 0.27 5.3%

R4 0.01 0.2% 0.26 5.2%

R5 0.02 0.4% 0.27 5.4%

R6 0.02 0.4% 0.27 5.4%

R7 0.03 0.7% 0.28 5.7%

R8 0.04 0.7% 0.29 5.7%

R9 <0.01 0.1% 0.25 5.1%

R10 0.00 0.1% 0.25 5.1%

R11 0.02 0.4% 0.27 5.4%

R12 0.01 0.1% 0.26 5.1%

R13 0.01 0.1% 0.26 5.1%

R14 0.01 0.1% 0.26 5.1%

R15 0.02 0.4% 0.27 5.4%

R16 0.01 0.3% 0.26 5.3%

R17 0.02 0.3% 0.27 5.3%

R18A 1st 0.03 0.7% 0.28 5.7%

R8B 0.03 0.7% 0.28 5.7%

R16B 0.01 0.3% 0.26 5.3%

R19A 1st 0.01 0.3% 0.26 5.3%

R19B 6th 0.01 0.3% 0.26 5.3%

R18B 4th 0.03 0.7% 0.28 5.7%

R20A GF 0.03 0.7% 0.28 5.7%

Riverside Energy Park Dispersion Modelling Report

PC (as % of PEC (as % of Receptor PC (µg/m3) PEC (µg/m3) AQAL) AQAL)

R20B 5th 0.03 0.7% 0.28 5.7%

R21 <0.01 0.1% 0.25 5.1%

R23 0.01 0.2% 0.26 5.2%

R24 0.00 0.1% 0.25 5.1%

R25 <0.01 0.1% 0.25 5.1%

R26 0.01 0.2% 0.26 5.2%

R27 <0.01 0.1% 0.25 5.1%

R22 0.03 0.6% 0.28 5.6%

Riverside Energy Park Dispersion Modelling Report

Appendix C Ecology Critical Loads

Riverside Energy Park Dispersion Modelling Report

C.1 Nitrogen Deposition Critical Loads

Lower Critical Upper Critical Maximum Site Habitat Type NCL Class Load Load Background (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) European and UK Designated Sites Inner Thames Marshes / Pioneer, low-mid, mid-upper Littoral Sediment 20 30 16.94 Rainham Marshes SSSI LNR saltmarshes Broadleaved, Mixed and Meso- and eutrophic quercus Oxlees Woodland 15 20 28.28 Yew Woodland woodland Epping Forest Acid grassland Inland dune siliceous grasslands 8 15 29.96 Broadleaved, Mixed and Acidophilous Quercus-dominated Epping Forest 10 15 54 Yew Woodland woodland Ingrebourne Marshes Fen, marsh and swamp Rich Fens 15 30 16.94 Broadleaved, Mixed and Meso- and eutrophic quercus Thorndon Park 15 20 27.58 Yew Woodland woodland Broadleaved, Mixed and Hainault Forest Broad leaved woodland 15 20 26.46 Yew Woodland Low and medium altitude hay Curtismill Green Neutral grassland 20 30 16.38 meadows West Thurrock Lagoon & Pioneer, low-mid, mid-upper Calidris aplina alpina 20 30 13.58 Marshes saltmarshes No comparable habitat with NCL Grays Thurrock Chalk Pit invertebrate assemblage NA N/A 10.36 class No comparable habitat with NCL Hangman's Wood & Deneholes Mixed species NA N/A 10.4 class Broadleaved, Mixed and Meso- and eutrophic Quercus Darenth Wood 15 20 26.32 Yew Woodland woodland Broadleaved, Mixed and Meso- and eutrophic Quercus Farningham Wood 15 20 28.7 Yew Woodland woodland

Riverside Energy Park Dispersion Modelling Report

Lower Critical Upper Critical Maximum Site Habitat Type NCL Class Load Load Background (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) Non-Statutory Designated Sites Crossness LNR Calcareous grassland Calcareous grassland 20 30 16.38 Broadleaved, Mixed and Broadleafed/Coniferous Lesnes Abbey LNR 10 20 28.42 Yew Woodland unmanaged woodland Broadleaved, Mixed and Broadleafed/Coniferous BxB103 10 20 28.42 Yew Woodland unmanaged woodland Coastal and Floodplain Low and medium altitude hay M039 20 30 16.94 Grazing Marsh meadows No comparable habitat with NCL M031 Rivers and Streams N/A N/A 16.94 class Standing Open Water and No comparable habitat with NCL B&DB103 N/A N/A 16.94 Canals class No comparable habitat with NCL HvBI18 Rivers and Streams N/A N/A 19.32 class No comparable habitat with NCL B&DBI07 Rivers and Streams N/A N/A 19.32 class Thamesmead Ecological Study Standing Open Water and No comparable habitat with NCL N/A N/A 19.32 Area Canals class Broadleafed/Coniferous BxL07 Wood-Pasture & Parkland 15 20 34.44 unmanaged woodland Standing Open Water and No comparable habitat with NCL BxBII02 N/A N/A 16.38 Canals class Broadleaved, Mixed and Broadleafed/Coniferous BxL16 10 20 34.44 Yew Woodland unmanaged woodland Broadleaved, Mixed and Lesnes Abbey Broadleaved deciduous woodland 10 20 28.42 Yew Woodland

Riverside Energy Park Dispersion Modelling Report

Lower Critical Upper Critical Maximum Site Habitat Type NCL Class Load Load Background (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) Coastal and Floodplain Low and medium altitude hay M041 20 30 19.32 Grazing Marsh meadows Coastal and Floodplain Low and medium altitude hay M041_A 20 30 19.32 Grazing Marsh meadows Moist and wet oligotrophic BxBI14 Acid grassland 15 25 19.32 grasslands: Standing Open Water and No comparable habitat with NCL BxBI02 N/A N/A 19.32 Canals class Standing Open Water and No comparable habitat with NCL BxBII26 N/A N/A 16.94 Canals class Standing Open Water and No comparable habitat with NCL BxBII25 N/A N/A 19.32 Canals class

Riverside Energy Park Dispersion Modelling Report

C.2 Acid Deposition Critical Loads

Maximum Minimum Critical Load (keq/ha/yr) Background Site Habitat Type Acidity Class (keq/ha/yr) CLminN CLmaxN CLmaxS N S European and UK Designated Sites Inner Thames Marshes / No comparable habitat with a Littoral Sediment N/A N/A N/A 1.21 0.2 Rainham Marshes SSSI LNR acidity class Broadleaved, Mixed and Oxlees Woodland Broadleaved woodland 0.357 2.72 2.363 2.02 0.2 Yew Woodland Epping Forest Acid grassland Acid grassland 0.223 0.438 0.87 2.14 0.18 Broadleaved, Mixed and Epping Forest Broadleaved woodland 0.142 1.73 1.535 3.86 0.22 Yew Woodland Ingrebourne Marshes Fen, marsh and swamp Not sensitive N/A N/A N/A 1.21 0.19 Broadleaved, Mixed and Thorndon Park Broadleaved woodland 0.142 2.645 1.775 1.97 0.19 Yew Woodland Broadleaved, Mixed and Hainault Forest Broadleaved woodland 0.357 2.97 2.55 1.89 0.18 Yew Woodland Curtismill Green Neutral grassland Acid grassland 0.438 2.78 1.64 1.17 0.15 West Thurrock Lagoon & Calidris aplina alpina Not sensitive N/A N/A N/A 0.97 0.2 Marshes Grays Thurrock Chalk Pit invertebrate assemblage Not sensitive N/A N/A N/A 0.7 0.23 No comparable habitat with acidity Hangman's Wood & Deneholes Mixed species N/A N/A N/A 0.74 0.23 class Broadleaved, Mixed and Darenth Wood Broadleaved woodland 0.142 1.34 1.198 1.88 0.22 Yew Woodland Broadleaved, Mixed and Farningham Wood Broadleaved woodland 0.142 1.573 1.365 2.05 0.23 Yew Woodland

Riverside Energy Park Dispersion Modelling Report

Maximum Minimum Critical Load (keq/ha/yr) Background Site Habitat Type Acidity Class (keq/ha/yr) CLminN CLmaxN CLmaxS N S Non-Statutory Designated Sites Crossness LNR Calcareous grassland Calcareous grassland 1.071 5.071 4 1.27 0.18 Broadleaved, Mixed and Lesnes Abbey LNR Broadleaved woodland 0.285 1.034 0.749 2.03 0.21 Yew Woodland Broadleaved, Mixed and BxB103 Broadleaved woodland 0.285 1.031 0.746 2.03 0.21 Yew Woodland Coastal and Floodplain No comparable habitat with acidity M039 N/A N/A N/A 1.21 0.19 Grazing Marsh class No comparable habitat with acidity M031 Rivers and Streams N/A N/A N/A N/A N/A class Standing Open Water and No comparable habitat with acidity B&DB103 N/A N/A N/A N/A N/A Canals class No comparable habitat with acidity HvBI18 Rivers and Streams N/A N/A N/A N/A N/A class No comparable habitat with acidity B&DBI07 Rivers and Streams N/A N/A N/A N/A N/A class Thamesmead Ecological Study Standing Open Water and No comparable habitat with acidity N/A N/A N/A N/A N/A Area Canals class BxL07 Wood-Pasture & Parkland Broadleaved woodland 0.357 8.612 8.255 2.46 0.24 Standing Open Water and No comparable habitat with acidity BxBII02 N/A N/A N/A N/A N/A Canals class Broadleaved, Mixed and BxL16 Broadleaved woodland 0.357 8.618 8.261 2.46 0.24 Yew Woodland Broadleaved, Mixed and Lesnes Abbey Broadleaved woodland 0.285 1.034 0.749 2.03 0.21 Yew Woodland

Riverside Energy Park Dispersion Modelling Report

Maximum Minimum Critical Load (keq/ha/yr) Background Site Habitat Type Acidity Class (keq/ha/yr) CLminN CLmaxN CLmaxS N S Coastal and Floodplain No comparable habitat with acidity M041 N/A N/A N/A 1.38 0.2 Grazing Marsh class Coastal and Floodplain No comparable habitat with acidity M041_A N/A N/A N/A 1.38 0.2 Grazing Marsh class BxBI14 Acid grassland Acid grassland 0.438 4.578 4.14 1.38 0.2 Standing Open Water and No comparable habitat with acidity BxBI02 N/A N/A N/A N/A N/A Canals class Standing Open Water and No comparable habitat with acidity BxBII26 N/A N/A N/A N/A N/A Canals class Standing Open Water and No comparable habitat with acidity BxBII25 N/A N/A N/A N/A N/A Canals class

Riverside Energy Park Dispersion Modelling Report

Appendix D Ecology Detailed Results Tables

Riverside Energy Park Dispersion Modelling Report

D.1 Impact of Emissions at Ecological Sites – As % of Critical Level

NOx SO2 HF NH3 Site Annual Mean Daily Mean Annual Mean Weekly Mean Daily Mean Annual Mean

European and UK Designated Sites Inner Thames Marshes / 1.6% 3.5% 0.9% 4.7% 0.7% 2.1% Rainham Marshes SSSI LNR Oxlees Woodland 0.1% 0.8% 0.2% 0.8% 0.2% 0.5% Epping Forest 0.1% 0.4% 0.1% 0.2% 0.1% 0.2% Epping Forest <0.1% 0.6% 0.1% 0.2% 0.1% 0.2% Ingrebourne Marshes 1.1% 2.0% 0.6% 2.2% 0.4% 1.4% Thorndon Park 0.1% 0.5% 0.2% 0.3% 0.1% 0.5% Hainault Forest <0.1% 0.3% 0.1% 0.2% 0.1% 0.2% Curtismill Green 0.1% 0.3% <0.1% 0.2% 0.1% 0.1% West Thurrock Lagoon & 0.2% 0.6% 0.1% 0.5% 0.1% 0.2% Marshes Grays Thurrock Chalk Pit 0.1% 0.4% <0.1% 0.3% 0.1% 0.1% Hangman's Wood & Deneholes 0.1% 0.2% <0.1% 0.2% <0.1% 0.1% Darenth Wood 0.1% 0.4% 0.1% 0.2% 0.1% 0.3% Farningham Wood 0.1% 0.4% 0.1% 0.3% 0.1% 0.2% Non-Statutory Designated Sites Crossness LNR 0.3% 4.6% 0.2% 2.5% 0.9% 0.4% Lesnes Abbey LNR 0.3% 2.7% 0.2% 2.4% 0.5% 0.4%

Riverside Energy Park Dispersion Modelling Report

NOx SO2 HF NH3 Site Annual Mean Daily Mean Annual Mean Weekly Mean Daily Mean Annual Mean

BxB103 0.3% 3.3% 0.2% 3.4% 0.7% 0.4% M039 1.5% 3.3% 0.9% 4.5% 0.7% 2.0% M031 1.7% 3.6% 1.0% 5.0% 0.7% 2.2% B&DB103 2.0% 6.7% 1.2% 6.8% 1.3% 2.6% HvBI18 1.5% 6.1% 0.9% 6.8% 1.2% 2.0% B&DBI07 0.3% 2.1% 0.2% 1.0% 0.4% 0.3% Thamesmead Ecological Study 0.6% 3.4% 0.4% 3.1% 0.7% 0.9% Area BxL07 1.0% 4.8% 0.6% 4.1% 1.0% 1.4% BxBII02 0.4% 3.6% 0.3% 3.2% 0.7% 0.6% BxL16 0.9% 4.4% 0.6% 4.0% 0.9% 1.3% Lesnes Abbey 0.3% 2.8% 0.2% 2.4% 0.6% 0.4% M041 <0.1% <0.1% <0.1% <0.1% <0.1% <0.1% M041_A <0.1% <0.1% <0.1% <0.1% <0.1% <0.1% BxBI14 0.7% 3.4% 0.4% 3.0% 0.7% 0.9% BxBI02 <0.1% 1.7% <0.1% 0.5% 0.3% 0.1% BxBII26 0.5% 2.9% 0.3% 2.0% 0.6% 0.6%

BxBII25 1.0% 5.8% 0.6% 4.7% 0.9% 2.5%

Riverside Energy Park Dispersion Modelling Report

D.2 Nitrogen Deposition Results

Process Contribution Site NCL Class Deposition Velocity PC N Dep % of Lower % of Upper Critical (kgN/ha/yr) Critical Load Load

European and UK Designated Sites Inner Thames Marshes / Pioneer, low-mid, mid-upper Grassland 3.74E-01 1.87% 1.25% Rainham Marshes SSSI LNR saltmarshes Meso- and eutrophic quercus Oxlees Woodland Woodland 4.72E-02 0.31% 0.24% woodland Epping Forest Inland dune siliceous grasslands Grassland 1.23E-02 0.15% 0.08% Acidophilous Quercus-dominated Epping Forest Woodland 1.93E-02 0.19% 0.13% woodland Ingrebourne Marshes Rich Fens Grassland 2.55E-01 1.70% 0.85% Meso- and eutrophic quercus Thorndon Park Woodland 5.10E-02 0.34% 0.26% woodland Hainault Forest Broad leaved woodland Woodland 1.58E-02 0.11% 0.08% Low and medium altitude hay Curtismill Green Grassland 1.39E-02 0.07% 0.05% meadows West Thurrock Lagoon & Pioneer, low-mid, mid-upper Grassland 4.09E-02 0.20% 0.14% Marshes saltmarshes No comparable habitat with NCL Grays Thurrock Chalk Pit Grassland 1.84E-02 - - class No comparable habitat with NCL Hangman's Wood & Deneholes N/A 2.11E-02 - - class Meso- and eutrophic Quercus Darenth Wood Woodland 2.68E-02 0.18% 0.13% woodland Meso- and eutrophic Quercus Farningham Wood Woodland 2.31E-02 0.15% 0.12% woodland

Riverside Energy Park Dispersion Modelling Report

Process Contribution Site NCL Class Deposition Velocity PC N Dep % of Lower % of Upper Critical (kgN/ha/yr) Critical Load Load

Non-Statutory Designated Sites Crossness LNR Calcareous grassland Grassland 7.48E-02 0.37% 0.25% Broadleafed/Coniferous Lesnes Abbey LNR Woodland 1.14E-01 1.14% 0.57% unmanaged woodland Broadleafed/Coniferous BxB103 Woodland 1.08E-01 1.08% 0.54% unmanaged woodland Low and medium altitude hay M039 N/A 5.65E-01 2.82% 1.88% meadows No comparable habitat with NCL M031 N/A 6.17E-01 - - class No comparable habitat with NCL B&DB103 N/A 7.34E-01 - - class No comparable habitat with NCL HvBI18 N/A 5.65E-01 - - class No comparable habitat with NCL B&DBI07 N/A 9.48E-02 - - class Thamesmead Ecological Study No comparable habitat with NCL N/A 2.39E-01 - - Area class Broadleafed/Coniferous BxL07 Woodland 3.81E-01 2.54% 1.91% unmanaged woodland No comparable habitat with NCL BxBII02 N/A 1.66E-01 - - class Broadleafed/Coniferous BxL16 Woodland 3.52E-01 3.52% 1.76% unmanaged woodland Lesnes Abbey Broadleaved deciduous woodland Woodland 1.14E-01 1.14% 0.57%

Riverside Energy Park Dispersion Modelling Report

Process Contribution Site NCL Class Deposition Velocity PC N Dep % of Lower % of Upper Critical (kgN/ha/yr) Critical Load Load

Low and medium altitude hay M041 N/A 1.03E-06 <0.01% <0.01% meadows Low and medium altitude hay M041_A N/A 5.84E-07 <0.01% <0.01% meadows Moist and wet oligotrophic BxBI14 Grassland 1.57E-01 1.05% 0.63% grasslands: No comparable habitat with NCL BxBI02 N/A 1.62E-02 - - class No comparable habitat with NCL BxBII26 N/A 1.73E-01 - - class No comparable habitat with NCL BxBII25 N/A 3.84E-01 - - class

Riverside Energy Park Dispersion Modelling Report

D.3 Acid Deposition Results

Process Contribution Site Acidity Class Deposition Velocity % of Minimum N (keq/ha/yr) S (keq/ha/yr) Critical Load

European and UK Designated Sites

Inner Thames Marshes / No comparable habitat Grassland 2.67E-02 3.86E-02 - Rainham Marshes SSSI LNR with acidity class

Oxlees Woodland Broadleaved woodland Woodland 3.37E-03 6.75E-03 0.37%

Epping Forest Acid grassland Grassland 8.80E-04 1.27E-03 0.49%

Epping Forest Broadleaved woodland Woodland 1.38E-03 2.76E-03 0.24%

Ingrebourne Marshes Not sensitive Grassland 1.82E-02 2.64E-02 -

Thorndon Park Broadleaved woodland Woodland 3.65E-03 7.31E-03 0.41%

Hainault Forest Broadleaved woodland Woodland 1.13E-03 2.26E-03 0.11%

Curtismill Green Acid grassland Grassland 9.91E-04 1.43E-03 0.09% West Thurrock Lagoon & Grassland 2.92E-03 4.22E-03 - Marshes Not sensitive

Grays Thurrock Chalk Pit Not sensitive Grassland 1.31E-03 1.90E-03 - No comparable habitat Hangman's Wood & Deneholes N/A 1.51E-03 3.02E-03 - with acidity class

Darenth Wood Broadleaved woodland Woodland 1.92E-03 3.84E-03 0.43%

Farningham Wood Broadleaved woodland Woodland 1.65E-03 3.30E-03 0.31% Non-Statutory Designated Sites

Crossness LNR Calcareous grassland Grassland 5.34E-03 7.72E-03 0.26%

Riverside Energy Park Dispersion Modelling Report

Process Contribution Site Acidity Class Deposition Velocity % of Minimum N (keq/ha/yr) S (keq/ha/yr) Critical Load

Lesnes Abbey LNR Broadleaved woodland Woodland 8.16E-03 1.63E-02 2.37%

BxB103 Broadleaved woodland Woodland 7.68E-03 1.54E-02 2.24% No comparable habitat M039 N/A 4.03E-02 8.09E-02 - with acidity class No comparable habitat M031 N/A 4.41E-02 8.83E-02 - with acidity class No comparable habitat B&DB103 N/A 5.24E-02 1.05E-01 - with acidity class No comparable habitat HvBI18 N/A 4.04E-02 8.09E-02 - with acidity class No comparable habitat B&DBI07 N/A 6.77E-03 1.36E-02 - with acidity class

Thamesmead Ecological Study No comparable habitat N/A 1.71E-02 3.42E-02 - Area with acidity class

BxL07 Broadleaved woodland Woodland 2.72E-02 5.45E-02 0.95% No comparable habitat BxBII02 N/A 1.19E-02 2.38E-02 - with acidity class

BxL16 Broadleaved woodland Woodland 2.51E-02 5.03E-02 0.88%

Lesnes Abbey Broadleaved woodland Woodland 8.12E-03 1.63E-02 2.36% No comparable habitat M041 N/A 7.33E-08 1.47E-07 - with acidity class

Riverside Energy Park Dispersion Modelling Report

Process Contribution Site Acidity Class Deposition Velocity % of Minimum N (keq/ha/yr) S (keq/ha/yr) Critical Load

No comparable habitat M041_A N/A 4.17E-08 8.36E-08 - with acidity class

BxBI14 Acid grassland Grassland 1.12E-02 1.62E-02 0.60% No comparable habitat BxBI02 N/A 1.15E-03 2.31E-03 - with acidity class No comparable habitat BxBII26 N/A 1.23E-02 2.47E-02 - with acidity class No comparable habitat BxBII25 N/A 2.75E-02 5.50E-02 - with acidity class