Earls Gate Energy Centre Limited Earls Gate Energy Centre. Permit Application

Transcription

1 Permit (Application) Number: PPC/A/ Applicant: Earls Gate Energy Centre Limited Earls Gate Energy Centre Limited Earls Gate Energy Centre Permit Application Application Number PPC/A/ CONTENTS 1 NON TECHNICAL SUMMARY OF DETERMINATION EXTERNAL CONSULTATION AND SEPA S RESPONSE ADMINISTRATIVE DETERMINATIONS INTRODUCTION AND BACKGROUND Historical Background to the activity and application/variation Description of activity Guidance/directions issued to SEPA by the Scottish Ministers under Reg.60 or Identification of important and sensitive receptors KEY ENVIRONMENTAL ISSUES Summary of significant environmental impacts Implications of the Variation on - Point Sources to Air Implications of the Variation on - Point Source Emissions to Surface Water and Sewer Implications of the Variation on - Point Source Emissions to Groundwater Implications of the Variation on - Fugitive Emissions to Air Implications of the Variation on - Fugitive Emissions to Water Implications of the Variation on - Odour Implications of the Variation on - Management Implications of the Variation on - Raw Materials Implications of the Variation on - Raw Materials Selection Implications of the Variation on - Waste Minimisation Requirements Implications of the Variation on - Water Use Implications of the Variation on - Waste Handling Implications of the Variation on - Waste Recovery or Disposal Implications of the Variation on - Energy Implications of the Variation for - Accidents and their Consequences Implications of the Variation for - Noise Implications of the Variation for - Monitoring Implications of the Variation for - Closure Implications of the Variation for - Site Condition Report Implications of the Variation for - Consideration of BAT OTHER LEGISLATION CONSIDERED ENVIRONMENTAL IMPACT ASSESSMENT AND COMAH DETAILS OF NON STANDARD PERMIT CONDITIONS EMISSION LIMIT VALUES OR EQUIVALENT TECHNICAL PARAMETERS/ MEASURES PEER REVIEW... Error! Bookmark not defined.

2 11 FINAL DETERMINATION REFERENCES AND GUIDANCE NON TECHNICAL SUMMARY OF DETERMINATION PPC requires that where the draft determination of an application or a SEPA initiated variation is to be subject to public consultation (this is usually referred to as PPD consultation) the decision document will contain a non-technical summary of the determination. There is no need to have a non-technical summary if the application is no subject to PPD Will the draft determination be subject to public consultation? Yes Earls Gate Energy Centre Ltd (EGEC) are proposing to build a Combined Heat and Power (CHP) plant based on a single line incinerator at Earls Gate Energy Park in Grangemouth burning nonhazardous waste to provide steam and electricity for the existing users at the Earls Road Chemical complex and for adjacent new industrial uses in Earls Gate Park. The scheme is designed so that 100% of steam generated will be consumed; any surplus electricity not required by these users will be exported to the National Grid, the proposals for energy recovery meet targets for energy recovery specified in SEPA s Thermal Treatment of Waste Guidelines. The proposed facility will come under the regulation of Chapter 4 Special provisions for Waste Incineration Plants and Waste Co-Incineration Plants in the Industrial Emissions Directive (IED) Dir 2010/75/EU by virtue of the fact that it is a Waste Incineration Plant. This means that stringent limits on operating conditions and requirements for continuous monitoring of emissions to air are applicable to limit impact to the environment and human health. Air dispersion modelling using two different models has been carried out to assess the predicted impact of emissions to air to human health and to ecological receptors. The modelling was a worst case assessment which assumed that pollutants are all emitted at the level of the emission limit values (ELV) when in practice actual emissions can be expected to be much lower. Two different models were used to assess the impact and 5 years of meteorological data. No exceedances of air quality standards for the protection of human health or ecological receptors were predicted and it is not anticipated that the proposed facility will cause any adverse impacts. The output from the air dispersion modelling was also used in a human health risk assessment (HHRA). SEPA is satisfied that the conclusions drawn in the HHRA are supported by the assessment and that no unacceptable risk to human health is presented by the proposed activities. However, due to historic levels of heavy metals in the area dispersion modelling of heavy metals will be required using actual data from stack monitoring within 6 months of completion of commissioning of the facility. This will allow the assumptions in the HHRA to be checked against real data. Environmental monitoring will be required by permit conditions to gather baseline soil data in the local area for dioxins, furans and heavy metal species prior to commissioning of the plant. The incineration line will burn 216,000 tonnes per annum of non-hazardous refuse derived fuel (RDF) based on an availability of 8000 hours per annum, but capable of burning up to a maximum of 236,500 tonnes per annum. The RDF is manufactured from municipal and commercial and industrial waste from which recyclable material (plastic, metals, paper, card, glass etc.) have been removed prior to delivery to the site. The facility comprises the following main equipment: two weighbridges for weighing materials and wastes in and out of the site; a waste reception area comprising a tipping hall, 2577 tonne capacity waste bunker and a

3 waste quarantine area. Waste delivery vehicles drive into one of 5 bays in the tipping hall and tip the RDF into the waste bunker. An overhead crane mixes the waste inside the bunker and delivers it to a waste feed chute; a single moving-grate incinerator linked to an integral water-tube heat recovery boiler, steam turbine and electrical generation equipment with an external air cooled condenser. The incinerator will operate with a minimum combustion gas temperature of 850 o C with a two second residence time low NOx gas burners will ensure the temperature is maintained above 850 o C when waste is burned. Incinerator bottom ash (IBA) collected from the grate is designed to meet specific limits on unburned carbon in ash as specified in permit conditions; equipment for water-cooling, storage and handling of IBA; flue gas treatment to reduce emissions to air and comprising injection of urea into the combustion chamber to reduce emissions of nitrogen oxides; a bag filter to reduce dust emissions; injection of hydrated lime upstream of the bag filter to absorb acid gases (sulphur dioxide, hydrogen chloride and hydrogen fluoride) and injection of activated carbon at the same location to remove VOCs including dioxins and furans and heavy metals including mercury. The treated flue gases will exhaust to atmosphere via a 79 metre stack; solid residues from flue gas treatment known as air pollution control residues (APCr) will be stored inside an external silo. The proposed stack height of 79m is an increase on the 70 metres stack height originally granted planning permission on 18 January 2017 Reference No. P/16/0321/FUL. A stack height assessment supporting the proposed stack height is provided in the air quality impact assessment in annex 4 of the PPC Application. demineralisation plant to treat mains water so it is suitable for use in the boiler for steam generation; storage of raw materials including internal storage of boiler chemicals and urea prills in 1 tonne bags; and external storage of fuel oil and silo s for storage of hydrated lime and powdered activated carbon; mains water/ fire water tank; emergency standby generator to provide safe shutdown in the event of a power cut; five gas-fired boilers, each with 12MWth steam output, to satisfy heat demand during periods of outage or when demand peaks above the CHP plant s design capacity. These will use low NOx emission burners and will vent to atmosphere via a common 35 metre stack. The proposed stack height of 35m is an increase on the 24 metres stack height originally granted planning permission on 18 January 2017 Reference No. P/16/0321/FUL; The entire facility has been designed so that noisy equipment (air-cooled condenser, the turbine hall and emergency generator) are situated away from the site boundary with Sensitive Receptors (housing on Wood Street and Jupiter Wildlife Centre) beyond, and is screened by process buildings. The majority of the process excluding the package boilers is also located inside process buildings including the abatement equipment for emissions to air and storage and handling of IBA. Steam vents required to protect the boiler from over-pressurisation have silencers fitted to minimise the noise associated with venting. Emissions of odour will be controlled by keeping doors closed except for entry and exit and maintaining the waste reception hall under negative pressure. The extracted air will either be treated by combustion in the incineration line when it is operational, or by treatment in carbon filters located on the roof and venting via a 47 metres stack when the incinerator is not operating. Dispersion modelling for odour emissions from the carbon filter has been provided; this demonstrates that odour from the carbon filters can be controlled to well below odour unit per cubic metre (1.5 to 1 OU E /m 3 ) of air at sensitive receptors; this is the threshold for offensive odour in ambient air specified in the SEPA Odour Guidance 2010 below which odours are unlikely to cause nuisance in the long-term (the lower threshold of 1 OU E /m 3 applies to more sensitive populations). Process effluent from the boiler blow-down will undergo adjustment for ph prior to reuse in the process for ash cooling. Routine effluent arisings will be discharged into the Calachem Weak stream for

4 discharge to the River Forth. Approximately 40% of the weak stream is diverted into the Calachem strong stream where it undergoes biological treatment in Calachem Effluent Treatment Plant which is regulated under PPC Permit Number PPC/A/ An impact assessment based on direct emissions to the River Forth has been carried out and has not predicted any significant impact associated with predicted emissions to water. In the event of a fire or large spill an isolation valve will prevent discharge into the Calachem drainage systems and containment kerbing around hardstanding areas will prevent spillage off-site. In the event of a fire inside the Waste Reception Area, firewater will be directed to the waste bunker. Any firewater collected following a fire will undergo testing prior to subsequent treatment or disposal at CalaChem Effluent Treatment plant or elsewhere depending on the composition and quantity. Glossary of terms APCr - Air Pollution Control residues BAT - Best Available Techniques BATC - BAT Conclusions BREF - BAT Reference Document CHP - Combined Heat and Power CO - Coordinating Officer EGEC - Earls Gate Energy Centre Limited ELV - Emission Limit Value IBA - Incinerator Bottom Ash IED - Industrial Emissions Directive PPC The Pollution Prevention and Control (Scotland) Regulations, 2012 RDF - Refuse Derived Fuel TOC - Total Organic Carbon TTWG - SEPA Thermal Treatment of Waste Guidelines VOC - Volatile Organic Compounds 2 EXTERNAL CONSULTATION AND SEPA S RESPONSE Is Public Consultation Required - Yes Advertisements Check: Date Compliance with advertising requirements Edinburgh Gazette 25 July 2017 Yes checked 14/08/2017 The Falkirk Herald 27 July 2017 Yes checked 14/08/2017 No. of responses received: None Summary of responses and how they were taken into account during the determination: Not applicable. Is PPC Statutory Consultation Required Yes Food Standards Agency: Yes, consulted on 23/08/2017 (missed in error when other statutory consultees consulted. Forth Valley NHS Health Board: Yes, consulted on 5/07/2017

5 Falkirk Council: Yes, consulted on 5/07/2017 Scottish Water: Not applicable as no sewer connection. Health and Safety Executive: N/A as not a COMAH establishment Scottish Natural Heritage (PPC Regs consultation): Yes, consulted on 5/07/2017 Harbour Authority: N/A as no discharge into the harbour Discretionary Consultation - Yes Consultee: Grangemouth Community Council Justification: Confirmed by Line Management that to be treated as a statutory consultee for any applications in Grangemouth Summary of response and actions taken: None received. Enhanced SEPA public consultation - Yes Details of enhanced public consultation Requested that placed on SEPA web-site in line with SEPA Policy as outlined in the Thermal Treatment of Waste Guidelines Off-site Consultation - No Transboundary Consultation - No Public Participation Consultation - Yes STATEMENT ON THE PUBLIC PARTICIPATION PROCESS The Pollution Prevention and Control (Scotland) Regulations 2012 (schedule 4, para 22) requires that SEPA s draft determination of this application be placed on SEPA s website and public register and be subject to 28 days public consultation. The dates between which this consultation took place, the number of representations received and SEPA s response to these are outlined below. Date SEPA notified applicant of draft determination 2 February 2018 Date draft determination placed on SEPA s Website 2 February 2018 Details of any other appropriate means used to advertise the draft to Grangemouth Community Council Date public consultation on draft permit opened Date public consultation on draft permit consultation closed Number of representations received to the consultation Date final determination placed on the SEPA s Website Summary of responses and how they were taken into account during the determination:

6 3 ADMINISTRATIVE DETERMINATIONS Determination of the Schedule 1 activity As detailed in the application and specified in the draft Permit Schedule 1 paragraph Determination of the stationary technical unit to be permitted: As detailed in the application and described in in the draft Permit Schedule 1 paragraph Determination of directly associated activities: As described in the draft Permit Schedule 1 paragraph Determination of site boundary As detailed in the application and inserted in Figure 1 in the draft Permit Schedule 1 paragraph 1.2. GUIDANCE NOTES TECHNICAL DETERMINATION 4 INTRODUCTION AND BACKGROUND 4.1 Historical Background to the activity and application The proposed Earls Gate Energy Centre is located in Grangemouth within the Falkirk Council Local Authority area. The site is located approximately 1.4km to the west of Grangemouth Town Centre and comprises approximately 2.7 Ha on the south west part of the existing CalaChem manufacturing facility. The land which the Facility will be located on is brownfield having previously been part of the then ICI and later Zeneca chemicals manufacturing activities; it is currently disused [Ref. 1]. The Applicant Earls Gate Energy Centre Limited, a 100% subsidiary of Hargreaves Services plc, applied for Planning Permission to Falkirk Council in 2016 which was granted on 18 January 2017 (Ref. P/16/0321/FUL). An application for a Permit to operate was made to SEPA on 27 April 2017 and accepted as Duly made on 3 July 2017 following receipt of further supporting information. Further information notices issued under Schedule 4 of the PPC Regulations were issued on 19 September, 19 October and 14 November 2017 (See Annex 1, 2 and 3 of the Administrative Decision document DD-01 for further details). At a meeting with the applicant on 2 October 2017 they notified SEPA of some intended changes to the application as submitted which would require an amendment to the approval in the Planning Permission which had been granted. This included a reduction in height of many buildings and an increase in efflux velocity and temperature from the main stack, environmentally this was expected to lead to improved dispersion of pollutants from the stack. An updated air quality impact assessment including the results of revised air dispersion modelling to take these changes into account was received by SEPA on 27 October 2017 in the response to the first two Schedule 4 Notices. A clarification response responding to additional questions on the responses to the first two Schedule 4 Notices was received on 30 November This included a summary document of the proposed

7 changes to the design since the original PPC application and planning approval. This included agreement to pursue a 35 metre stack height for the common boiler vent stack instead of 33m in the original PPC Application and 24 metre stack height approved at Planning, and an odour control system and stack as requested by SEPA due to the proximity of the proposed facility to sensitive receptors (nearest residential areas are approximately 0.4 Km to the south and south east) See Section 5.7 for further details. This response also included further details of the BAT techniques to minimise noise which were considered critical to determination of the permit by SEPA due to the close proximity to sensitive receptors See Section 5.7 for further details. 4.2 Description of activity The proposed facility is described by the Applicant as a Replacement CHP Plant because it will replace existing combustion equipment used to generate steam for Earls Gate Chemical Complex. The new plant is designed to meet the steam demand of existing users and new/ future users on Earls Gate Park and will generate electricity with any surplus exported to the National Grid. The facility comprises a CNIM-MARTIN moving grate single line Incinerator with a typical capacity of 216,000 tonnes per annum (tpa) of residual refuse derived fuel (RDF) based on 8000 hours operation per annum (maximum theoretical capacity of 236,000 tpa). The RDF is likely to be derived mainly from residual Commercial and Industrial waste from which the recyclates have been removed. In addition to the incineration line the facility will include five 12MWth boilers to provide additional steam during peak demand periods or when the incineration line is not operating. Refer to the Non-Technical Summary in Section 1 of this document and Schedule 1 of the Permit for further details. The Plant falls under Chapter IV of IED for the incineration of waste and the following activities in Schedule 1 of the Pollution Prevention and Control (Scotland) Regulations ( the Regulations or PPC 2012 ): for the incineration line in Part A of Section 5.1 paragraph (b) of Schedule 1 to the Regulations as incineration of non-hazardous waste in an incineration or co-incineration plant; and, for the package boilers the combustion of natural gas to produce steam as described in Part A Section 1.1 of Chapter 1 of Part 1 of Schedule 1 to the Regulations as burning any fuel in a boiler or furnace with a rated thermal input of more than 20 megawatts and less than 50 megawatts. Because the package boilers are individually below 15 MW input each, they do not fall under Chapter III of IED because the aggregation rules do not apply. Therefore whilst they do fall under PPC Part A, the rules for Large Combustion Plants in Chapter III of IED do not apply. 4.3 Guidance/directions issued to SEPA by the Scottish Ministers under Reg.60 or 61. None. 4.4 Identification of important and sensitive receptors To the north, the site is bound by the existing CalaChem facility, with the A904 Earls Road located further beyond. A railway line bounds the site to the south, with residential housing and the Jupiter Wildlife Centre beyond. To the east, the site is bound by unoccupied land and to the west the site is bound by Earls Gate Park. The site is accessed via Earls Road to the north. Trees and scrub along the northern railway boundary and dense woodland plantation to the south provide visual screening to the southern site boundary [Ref. Initial Permit Application Aril 2017]. Key receptors are as follows: 1. Human health receptors and air quality management area 2. Special Protection Area s, Sites of Special Scientific Interest and Ramsar sites.

8 4.4.1 Human health receptors and air quality management area The installation is located in Grangemouth, population 18,500. The most sensitive residential receptor locations, bearing in mind the prevailing south westerly wind direction, are considered to be; (i) Wood Street and streets further south (south of the site). (ii) Grangemouth Town Centre (south, east and north east of site) (iii) Grangemouth Auld Town (north and north west of the site) As identified in 4.1 above, the nearest residential receptors are located approximately 300 metres to the south and south east of the installation boundary on Wood Street [Ref. Section 2 of Annex 2 Initial Site Report provided in original application] and streets further to the south. A total of 23 sensitive human health receptors were assessed in the air quality impact assessment, human health risk assessment (HHRA) and odour impact assessment, these are detailed in Table over-leaf. The assessments consider the possible effects on human health at key receptors, where humans are likely to be exposed to the greatest impact from the proposed impact, and at the point of maximum impact of annual mean emissions. For the purposes of the HHRA the results of which are discussed in Section 5.2.3, Residential and Agricultural receptors were identified and can be defined as follows: Residential: A known place of residence that is occupied within the study area; Agricultural: A farm holding or area land of horticultural interest. In addition to the specific receptors identified in the Air Quality Assessment a Point of maximum impact receptor has been selected at the point of maximum impact, it should be noted that this point is actually within the industrial area and uninhabited. An impact for an agricultural receptor is typically predicted to be greater than a residential receptor due to the additional pathways considered. Therefore, as a conservative assessment, the agricultural receptor has been applied by the Applicant at the sensitive receptors identified as schools below [Ref. Human Health Risk Assessment submitted with Application]. Figure shows the specific locations of these receptors relative to the proposed facility. Table Location of sensitive receptors and point of maximum impact [Ref. Table 5.1 in Updated Air Quality Assessment [Appendix K of 1 st and 2 nd Schedule 4 Response]. ID Receptor Name Location Receptor type Eastings Northings MAX Point of maximum impact Agricultural / Residential R1 46 Wood Street Residential R2 2 Wood Street Residential R3 29 Wood Street Residential R4 3 Wood Street Residential R5 1 Primrose Avenue Residential R6 14 Stuart Grove Residential R7 5 Beancross Road Residential R8 59 Portal Road Residential R9 69 S Lumley Street Residential R10 Forth House Residential R11 43 Dundas Street Residential R12 Earls Road Residential R13 4 W Church Drive Residential R14 62 Dalgrain Road Residential R15 7 Zetland Drive Residential R16 Glensburgh Road Residential R17 2 Carronview Residential R18 The Grange Manor Residential R19 Beancross Primary Agricultural

9 School R20 School on Torwood Residential Avenue R21 Moray Primary School Agricultural R22 Building adjacent to Residential Earl's Gate Roundabout R Almond Street Residential

10 Figure Location of sensitive receptors assessed for the air dispersion modelling, human health risk assessment an odour impact assessment [Ref. Figure 6 in Updated Air Quality Assessment [Appendix K in 1 st and 2nd Schedule 4 Response]. The proposed facility is located within the Grangemouth Air Quality Management Area (AQMA) which has been specified due to a likely breach of the sulphur dioxide 15 minute mean objective, as specified in the Air Quality (Scotland) Regulations This is due to emissions from the Petrochemical complex in Grangemouth. An action plan, aimed at achieving a reduction in sulphur dioxide levels within the designated area is in place. The local air quality management (LAQM) Annual Progress Report for 2016 from Falkirk Council stated that the SO 2 objective had not been breached for three consecutive years. However, Falkirk Council consider the AQMA remains justified based on the 2014 monitoring results

11 where the 15 minute objective for SO 2 was close to being breached at the Grangemouth Municipal Chambers ambient monitoring site. Sulphur dioxide (SO 2 ) emissions are discussed in Section of the Decision Document in terms of predicted impacts to air from the proposed facility. SO 2 emissions from the proposed facility in isolation are not anticipated to be a significant contributor to the AQMA. The other nearest AQMA is in Falkirk town centre which has been declared for the annual mean for NO 2 and PM10. This is approximately 2.5 Km to the South West of the site (See Figure 1 in Appendix A of the Updated Air Quality Impact Assessment [Appendix K in 1 st and 2nd Schedule 4 Response]. Figure Location of the Grangemouth Air Quality Management Area Ecological receptors As discussed above the proposed facility is on the other side of the railway immediately to the north of the Jupiter Wildlife Centre which is managed by Scottish Wildlife Trust. There are several designated ecological receptors within 15 Km of the proposed facility. The closest of these is the Firth of Forth RAMSAR, Special Protection Area (SPA) and Special Site of Scientific Interest (SSSI) which runs along both sides of the River Forth and is approximately 1.5 Km at the closest point. Table below summarises the sensitive ecological receptors which have been assessed. Figure shows the location of these sites.

12 Table Sensitive Ecological Receptors within 15 Km of the site [Ref. Table 5.2 in Updated Air Quality Assessment [Appendix K in 1 st and 2nd Schedule 4 Response]. ID Site Designation Location Distance from stack at closest X Y point (Km) European Designated Sites - Firth of Forth RAMSAR, SPA, SSSI Multiple points 1.5 E1 Black Loch Moss SAC E2 Blawhorn Moss SAC E3 Slamannan Plateau SPA E4 West Fannyside Moss SPA UK Designated Sites E5 Avon Gorge SSSI E6 Balquhidderock Wood SSSI E7 Bomains Meadow SSSI E8 Carriber Glen SSSI E9 Carron Dams SSSI E10 Carron Glen SSSI E11 Craigmad Wood SSSI E12 Darning Moss SSSI E13 Dullatur Marsh SSSI E14 East Kirkton Quarry SSSI E15 Gartmorn Dam SSSI E16 Howierig Muir SSSI E17 Linlithgow Loch SSSI E18 Linn Mill SSSI E19 Lochcote Marsh SSSI E20 Lockshaw Mosses SSSI E21 Peterhill SSSI E22 Philipstoun Muir SSSI E23 West Moss SSSI

13 Figure Ecological Sensitive Receptors [Ref. Figure 7 in Updated Air Quality Assessment [Appendix K in 1 st and 2nd Schedule 4 Response].

14 5 KEY ENVIRONMENTAL ISSUES 5.1 Summary of significant environmental impacts The process is a standard moving grate incineration plant capable of burning a maximum of 236,000 tonnes of non-hazardous RDF per annum. Back up energy is provided by 5 gas-fired package boilers. The key potentially significant impacts of the proposed facility are emissions to air and water, management of residues, odour and noise. These are discussed further in Sections 5.2, 5.3, 5.13, 5.14, 5.7 and 5.17 below together with details of the BAT techniques for their management. 5.2 Point Sources to Air Key emissions and ELVs. Incineration line One of the key issues associated with the proposed facility is the extent and impact of emissions to air. In addition to carbon dioxide and water vapour from combustion of fuel, the principal emissions from the incineration line will be oxides of nitrogen (NOx), oxides of sulphur (SOx), carbon monoxide, hydrogen chloride and hydrogen fluoride gases, particulate matter (PM), heavy metals, and volatile organic compounds (VOCs) which may include dioxins and furans. These substances when emitted from incineration appliances are subject to the requirements of the Chapter 4 of the Industrial Emissions Directive (IED) which requires compliance with specific emission limit values (ELVs) as set out in IED Annex VI. The details of the main stack, emission point A1 and the associated ELVs required to meet the requirements of IED Annex VI have been specified in Table s 6.1 and 6.2 in the draft Permit. Additional emissions which are not specifically regulated under IED include ammonia and nitrous oxide associated with urea injection to abate emissions of NOx. An ELV has been specified for ammonia but not for nitrous oxide for which a requirement is specified in Table 6.2 of the draft Permit for monitoring only. The ELV specified for ammonia is 10 mg/m 3 (daily average) and 10 mg/m 3 (average over sample period for periodic monitoring) which is consistent with ELVs set in Permits for other waste incineration plants in Scotland and the standard PPC template IED-T-14. Regulation 29(2) of PPC 2012 also requires that the monitoring requirements for dioxins and furans referred to in Part VI paragraph 2.1(c) in Annex VI of IED are taken to include polycyclic aromatic hydrocarbons (PAHs) and dioxin-like polychlorinated biphenyls (PCBs). Monitoring requirements for these parameters have therefore also been included in Table 6.2 the Permit but no ELVs have been set. The application states that for the proposed incineration plant the IED emission limits will be complied with and that under normal operating conditions emission discharge concentrations lower than the IED limits will be achieved. Data to support this statement from an existing similarly equipped facility already in operation was supplied in response to Appendix E of the Additional Information for Duly Making (Document Ref. S JRS 16/06/2017). This data has been assessed and SEPA is satisfied that the proposed technology is capable in principle of meeting the IED ELVs. Control of input materials to the incinerator is important in ensuring that emissions remain within ELVs. In this respect the waste acceptance criteria and procedures are designed to ensure sufficient control of waste inputs to the facility. Air emissions testing will be carried out continuously on the discharged combustion gases from the incineration line for many parameters and also periodically throughout the permit lifetime for all relevant parameters to ensure that the IED Emission Limit Values are met in practice. Periodic monitoring will also be undertaken for NOx on the package boilers.

15 Package boilers In addition to emissions to air of carbon dioxide and water vapour from fuel combustion, the five gas-fired package boilers will also emit carbon monoxide and NOx. These boilers will be regulated under the Medium Combustion Plant Directive (EU) 2015/2193 which is applicable from 20 December 2018 for new plant in Annex II Part 2 Table 1. The ELV for NOx specified in the Medium Combustion Plant Directive for this size of boiler is 100 mg/m 3. However, a lower ELV of 85 mg/m 3 for NOx has been specified in Table 10.2 in Schedule 10 of the Permit because this is the value which was specified as the hourly average concentration in air dispersion modelling to assess long-term impacts. This should be easily achievable on a new boiler with low NOx burners. Schedule 10 of the Permit will need to be varied prior to 20 December 2018 to include specific requirements to ensure compliance with MCPD. These have not yet been transposed into legislation in Scotland although this is imminent at the time of drafting the decision document. Modelling of CO, particulate matter and SO 2 was carried out for the boilers. However, MCPD does not require ELVs for CO although it does require monitoring, nor does it require ELVs for SO 2 or particulate matter from gas-fired boilers as emissions of SO 2 and particulate emissions are usually low from gasfired combustion plant. Additional standard conditions for the vents from the incineration line and the gas-fired boilers are also required to meet the general standard requirement that all emissions to air other than steam or water vapour, shall be colourless and free from persistent mist, fume and droplets (Ref. Permit Conditions and respectively. The ELVs, monitoring requirements and conditions described above for the incineration line and the package boilers are considered to be BAT for the installation. Discussion on monitoring techniques is provided in Section 5.18 of this document Predicted Impacts of Emissions to Air The impact of emissions to air from the proposed development are considered in the following documents in support of the Permit Application; Section (Document Ref. S JRS) and Annex 4 (Document Ref. S RSF 27/04/2017) of the Earls Gate Energy Centre Replacement CHP Plant Supporting Information in the Initial Application. Annex 4 of the Application contained the following assessments: Air Quality (Impact) Assessment, Human Health Risk Assessment (HHRA); Ecological Interpretation of AQA; Abnormal Emissions Assessment and Greenhouse Gas Assessment. The Air Quality Assessment (AQA) includes stack height analysis. Sections 8 and 13 and of the 1 st and 2nd Schedule 4 Further Information Notice response (Document Ref. S JRS 17/11/2017) and Appendix K Updated Air Quality Assessment (Document Ref. S RSF 26/10/2017)) Response to 3 rd Schedule 4 Response (Earls Gate Energy Centre Limited, Earls Gate Energy Centre Schedule 4 Response Document Ref. S JRS 1/12/2017) containing an updated HHRA in Appendix A (Document Ref. S RSF) and Detailed Results Tables Operation at ELVs in Appendix in Appendix B (Document Ref. S JRS 1/12/2017). Sections 5 Air Quality Impact Assessment answer to Q23 in the Clarifications Response (Document Ref. S JRS 1/12/2017). The information below is based on all of the responses above. Dispersion Modelling Study In order to demonstrate the potential impact of the proposed facility the Application has undertaken air dispersion modelling using two new generation dispersion models: ADMS 5.2 and AERMOD. These models are recommended for use by UK Regulators for assessing the impacts of emissions to air from new facilities. The models predicts ground level concentrations for each pollutant. These values are then

16 compared to air quality, standards and objectives (air quality assessment levels (AQALs)) and background data where relevant to assess impact. Cumulative impacts of the proposed facility combined with emissions from transport and other facilities which have planning permission including the proposed Forth Energy Biomass Plant were modelled as part of the Planning Application (May 2016). No exceedances of air quality standards for the protection of human health were predicted. (i) Air Quality Standards, Objectives and Guidelines In the UK, ambient concentrations of pollution are controlled by a number of air quality standards and objectives which are described in The Air Quality Strategy for England, Scotland, Wales and Northern Ireland 2007 (the AQS). In Scotland these air quality objectives are implemented via the Air Quality (Scotland) Regulations For pollutants not directly covered by this Regulation, guidance is available in Appendix D of PPC horizontal guidance note IPPC H1 issued in This provides both long-term (LT) and short-term (ST) Environmental Assessment Levels (EALs) for the protection of human health and the environment. EALs specified in the Environment Agency s environmental management guidance Air Emissions Risk assessment for your Environmental Permit (Air Emissions Guidance) are also considered. When the AQS does not contain relevant objectives the LT and ST EALs from these documents are therefore used to assess potential impacts. Standards and objectives for the protection of sensitive ecosystems and habitats are also contained within IPPC H1, the Air Emissions Guidance and the Air Pollution Information System (APIS). The Air Quality Assessment Levels (AQALs) used in the study are summarised in Tables 3.2 to 3.4 in the Updated AQA. (ii) Background Data Background ambient data for the pollutants assessed was used to assess current levels of pollutants. Local data from ambient monitoring station was used where possible, this was supplemented with UK data where this was not available. This is identified in Section 4 of the Updated AQA for each pollutant and the data used for further assessment is summarised in Table (iii) Summary of Atmospheric dispersion modelling study inputs The atmospheric dispersion modelling study was undertaken in order to assess the potential impacts of releases from the proposed facility, in relation to both local human health and the local environment. Two scenarios were modelled: Long-term impact - Operation of the incineration line and two package boilers to represent the typical operating conditions. This assumed continuous operation at the ELVs over the entire year when in reality emissions will be below ELVs and the incineration line will be off for periods of maintenance; and, Short-term impact - Operation of all five package boilers simultaneously when the incineration line is not operational. The study, assumed the worst case operational scenario i.e. that the pollutants are continually discharged at the IED ELVs (daily or half-hourly, as appropriate). VOCs were modelled at the ELV assuming that 100% of the emission was either benzene or 1,3 butadiene. Pollutants where no ELV is specified in IED i.e. nitrous oxide, dioxin-like PCBs, and PAHs as represented by benzo(a) pyrene were modelled at typical/ maximum emission concentrations for operating UK incineration plants. All concentrations were converted to grams per second (g/s) release rates for input into the model by multiplying the concentrations by the stack flow rate. The calculations to determine the g/s input data were checked and found to be satisfactory. The model took account of the following: effects of prevailing meteorological conditions including wind speed and direction, temperature, humidity and cloud cover. Although there is a meteorological (Met.) station at Grangemouth Municipal Chambers this is not an official Met Office site and the data does not include cloud cover or relative humidity which are required to run the model. Met Data for the years 2011 to 2015 was therefore taken from the Gogarbank Met station at Edinburgh Airport approximately 23 Km south east of the facility. Five years of data is assessed to take into account the inter-annual fluctuations in weather conditions. A comparison to wind-rose data from the Grangemouth Met

17 Station was requested by Schedule 4 Further Information Notice this was discussed in Section 8.2 of the Updated AQA and illustrated in figure 13 of Appendix A. A sensitivity analysis to assess the differences between the two sets of Met data was carried out by undertaking modelling for This concluded that whilst the choice of weather data has a slight effect on the predicted point of maximum impact the general dispersion and modelled results are similar and would not change the conclusions of the assessment. building effects which can affect the dispersion of the plume (building downwash effects). These were remodelled from the initial Permit Application as presented in the Updated AQA because slight design modifications since the application meant that efflux temperature and velocity from the main stack, and some building heights including parts of the boiler building (Boiler Hall A and B), had reduced. These factors have had a positive impact on dispersion so that ground level concentrations (GLC) in the updated assessment are slightly lower than those in the initial application. local topography for assessment of impacts within the gridded area; The model was used to predict the GLC of pollutants on a long-term and short-term basis at the following locations: across a 4.95Km by 4.95 Km grid of points with the main stack at the centre and a spacing of 49.5m as identified in figure 9 in appendix a of the Updated AQA; and at 23 specific human health receptors at the closest houses and local schools and 23 ecological receptors at designated sites as identified in Section 5 and Figures 6 and 7 in the Updated AQA, and reproduced in Section 4.3 above. The modelling approach and the details of model input and model set-up have been assessed by SEPA s air dispersion modelling specialists who have confirmed these are satisfactory. A summary of their findings is presented in Annex 3 to this document. (iv) Stack Height Assessment A stack height screening assessment was undertaken to determine an appropriate discharge stack height for the discharge stack from the incineration line and from the package boilers common stack (Section 7 of the Updated AQA). This stack height analysis took a phased approach with the stack height for the CHP Plant and the gas fired boilers being determined separately before assessing the combined impact of the plants to confirm that the stack heights are appropriate. All impacts were calculated as the maximum predicted impact across the modelling domain based on all 5 years of weather data, and are presented as a percentage of the AQAL. IPPC H1 (2003) states that to screen out insignificant process contributions: 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. These criteria has been applied as part of this stack height analysis. A sensitivity screen analysis was carried out using a range of possible stack heights between 50m and 100m. The results indicated that 79m was the optimum stack height for the incineration line and that 35m was the optimum stack height for the package boilers. These heights were therefore used for all elements of the main modelling assessment. SEPA accepts this assessment of the data. However, this will require the original Planning Permission to be revised as this is for stack heights of 70m and 24m for the incineration line stack and the package boilers common stack respectively. The Operator was expected to apply for a change to the Planning Permission at the time of drafting the Decision Document Assessment of Impact (human health receptors) Outputs from the ADMS model and comparative modelling with AERMOD were used in all assessments of impact at the maximum gridded receptor location as a cross check to assure the validity of the modelled outputs and to provide a view on the sensitivity of the modelling approach. This confirmed that ADMS 5.2 produced the higher results and it was therefore the most conservative of the two models.

18 The predicted ground level concentrations, known as the process contribution (PC) from modelling are compared to the long-term and short-term AQALs according to the methodology in IPPC H1 to assess impact. Where necessary ambient data is added to the PC to calculate the predicted environmental concentration (PEC) at the point of maximum impact and the PC and PEC at areas of public exposure. The IPPC H1 methodology for impact assessment of predicted ground level concentrations from emissions to air is summarised as follows: For long-term (LT) impacts If the PC is <1% of the AQAL it can be screened out as insignificant If PC is >/= 1% of the long-term AQAL, the PC plus the ambient data, the LT PEC is compared to the AQAL; If the PEC is <70% there is little risk of the AQAL being exceeded. For short-term (ST) impacts If the PC is <10% of the short-term AQAL it can be screened out as insignificant If PC is >/= 10% of the AQAL, the PC plus the 2 x the ambient data, ST PEC is compared to the AQAL; If the ST PC is <20% of the headroom between the AQAL and twice the background concentration, there is little risk of the AQAL being exceeded The long-term 1% PC 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. The short-term 10% PC threshold is based on the judgement that spatial and temporal conditions mean that short-term contributions are transient and are limited in comparison with long-term process contributions; and, the threshold provides a substantial safety margin to protect health and the environment [Ref. Section 9 Updated Air Quality Assessment in 1 st and 2 nd Schedule 4 Notice Response]. Assessment impact of long-term process contribution (Operation of the incineration line and two package boilers) The predicted ground level concentration (GLC) values,, the Process Contribution (PC) at the point of maximum impact from routine operation (incineration line plus 2 package boilers) based on emission at the daily average ELVs and maximum 30 minute average ELVs where relevant, have been compared to the Long and Short-term AQALs in Section 9 of the Updated Air Quality Assessment in Appendix K of the 1 st and 2 nd Schedule 4 Response. The results in Table 9.1 and Table 9.3 present the PC from modelling at the Daily ELVs using ADMS 5.2 and AERMOD respectively. The results in Table 9.2 and Table 9.4 present the PC from modelling at the Daily ELVs using ADMS 5.2 and AERMOD respectively. Tables 9.1 and 9.2 have the higher predicted ground level concentrations than Tables 9.3 and 9.4, confirming that ADMS is the more conservative of the two models. The modelling results from ADMS compared to the LT and ST AQALs are summarised for the highest year in Table overleaf. Contour plots showing the results plotted over a map of Grangemouth are provided for each averaging period and pollutant are provided in Appendix A of the updated air quality assessment.

19 Permit (Application) Number: PPC/A/ Applicant: Earls Gate Energy Centre Limited Table Dispersion Modelling Results using ADMS 5.2 GLC at point of greatest impact (normal operating condition - incineration line and 2 boilers operating) Pollutant Quantity Units AQAL Background PC PC% of Significant? PEC PEC% of Significant? Concentration AQAL (PC+Bg) AQAL (Bg) Nitrogen dioxide Sulphur dioxide Annual mean 1 ug/m (2011) 4.81% Yes % Yes th %ile of ug/m (2011) 7.82% No hourly means th %ile of ug/m (2011) 2.46% No daily means rd %ile of ug/m (2011) 5.63% No hourly means th %ile of 15 ug/m (2013) 8.17% No min. means2 PM10 Annual mean 1 ug/m (2011) 0.8% No 99.1 th %ile of ug/m % No daily means 2 (2011) PM2.5 Annual mean 1 ug/m (2011 & 1.43% Yes 2015) % Yes 0.05 (using assumption only 33% is PM2.5) 0.5% No Carbon 8 hour running ug/m 3 10, (2014) 0.17% No monoxide mean 2 Hydrogen Annual mean 1 ug/m (2011) 0.53% No chloride Hourly mean 2 ug/m (2011) 1.08% No Hydrogen Annual mean 1 ug/m (all 0.07% No fluoride years) Hourly mean 2 ug/m (2011) 0.34% No Ammonia Annual mean 1 ug/m (2011) 0.06% No Hourly mean 2 ug/m (2011) 0.05% No VOCs as Annual mean 1 ug/m % Yes % No benzene (2011) Hourly mean 2 ug/m (2011) 1.38% No VOCs as 1,3 Annual mean 1 ug/m % Yes % No butadiene (2011) Mercury Annual mean 1 ug/m % No (2011)

20 Pollutant Quantity Units AQAL Background Concentration PC (Bg) Hourly mean 1 ug/m (2011) Cadmium Annual mean 1 ug/m (2011) Hourly mean 1 ug/m (2011) Thallium Annual mean 1 ug/m (2011) Hourly mean 1 ug/m (2011) Total Group III Annual mean 1 ug/m metals (2011) Hourly mean 1 ug/m (2011) Arsenic Annual mean 1 ug/m (ELV) PC% of AQAL 0.09% No Significant? PEC (PC+Bg) PEC% of AQAL 10.59% Yes % No 0.45% No 0.05% No 0.02% No See metals assessment below % (ELV) Yes (LT ELV) % (LT ELV) Significant? Yes (Typical - As is 5% of ELV) Hourly mean 1 ug/m (ELV) Antimony Annual mean 1 ug/m (ELV) Hourly mean 1 ug/m (ELV) Chromium Annual mean 1 ug/m (ELV) Hourly mean 1 ug/m (ELV) Chromium VI Annual mean 1 ug/m (ELV) 8.82% (Typical - As is 5% of ELV) 4.5% (ELV) 0.11% (ELV) 0.04% (ELV) 0.11% (ELV) 0.04% (ELV) 2647% (ELV) Yes No No No No No Yes (Typical - As is 5% of ELV) (LT ELV) 35.16% (Typical - As is 5% of LT ELV) 3963% (LT ELV) No Yes (Typical) or (Wilton 11 Data) 0.79% (Typical CrVI is 0.03% of ELV; 0.033% of No (Typical data and Wilton 11 data) % (Typical and Wilton 11 data) Yes But no further assessment required as PC<1% of