Carbery Group. Primary Fuel Switch Proposal. Ambient Air Pollution Impact For inspection purposes only.

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1 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact CARBERY GROUP Ref: 0005_3 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact Prepared by: Andrew Shepherd BSc MSc PhD Energy Consultant Select Energy Solutions Silverhill Ballyderown Kilworth County Cork Tel. (0) M Prepared for: Carbery Group Ballineen West Cork June 2005 Page 1 of 15 EPA Export :18:12:04

2 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact Table of Contents 1. Summary Assumptions Steam Consumption Rates for the Oil and Gas Scenarios Flue Gas Flow Rates and Pollutant Concentrations for the Gas Scenario Flue Gas Flow Rates Flue Gas Pollutant Concentrations Flue Gas Flow Rates and Pollutant Concentrations for the Oil Scenario Flue Gas Flow Rates Flue Gas Pollutant Concentrations Estimation of Absolute Pollutant Emissions Air Dispersion Modelling Results of Background Ambient Air Pollution Monitoring General Monitored Data Updated Air Dispersion Modelling Results & Conclusions Annexes Page 2 of 15 EPA Export :18:12:04

3 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 1. Summary For economic and security of supply reasons, the Carbery Group propose switching, or to have the option of switching, from natural gas to oil as a primary energy source for a proportion of their steam production requirements at the Ballineen factory in West Cork during the period October to March inclusive. Five steam boilers and one CHP plant are currently used to provide factory steam requirements. All plant operates using natural gas with two steam boilers capable of co-firing with methane (bio-gas) as the primary energy source, i.e. gas scenario. The proposed oil scenario uses light oil in boilers 1, 2, 3 and 4, biogas in boiler 5 and does not operate the CHP plant during the period March to October inclusive. This represents an extreme scenario. For practical and operational reasons, Carbery may operate somewhere between the two scenarios considered. The steam boilers are fitted with dual fuel burners capable of operating on oil or gas. Under IPC licence 596, the Carbery Group are only permitted to operate the steam boilers and CHP using natural gas and bio-gas. The Carbery Group have approached the EPA with the objective of obtaining permission to operate boilers 1,2, 3 and 4 using oil as required between the months of October and March. A number of investigations have been carried out to provide the EPA with requested information on pollutant emissions of the proposed fuel switch. This report brings together the various studies and reports into a single document and summarises the main findings. The main studies referred to in this document are: Study 1. Assessment of Pollutant Emissions Impact: Fuel Switch Gas Oil (Select Energy Solutions October 2004) see Annex 1. (Compares absolute emissions of NO x and SO 2 for the gas and oil scenarios.) Study 2. Air Pollution Modelling (SWS Group December 2004) see Annex 2. (Compares ground level pollutant concentrations for the gas and oil scenarios estimated using a validated air dispersion computer model). Validation of the computer model is provided in Annex 3. Study 3. Monitoring of ambient pollutant concentrations at the Carbery site. Monitoring carried out by Enviro Technology Ltd. Results used to establish ambient background concentrations of NO 2 and SO 2. (Data provided by Enviro Technology. Findings presented in this document) The estimated impact on total pollutant emissions for the period October to March inclusive for the gas and oil scenarios (Study 1) is summarised in Table 1. Gas Scenario Oil Scenario NO x Emissions (tonnes) SO 2 Emissions (tonnes) CO 2 Emissions (tonnes) 24,602 25,100 Table 1. Total estimated pollutant emissions (October to March inclusive) for the gas and oil scenarios. Predicted NO x and SO 2 emissions for the operating period October to March are higher where oil is used as the primary energy source as would be expected. CO 2 emissions are similar under both the gas and oil operating scenarios. Page 3 of 15 EPA Export :18:12:04

4 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact Background pollution levels established from the ambient monitoring of air in the locality of the Carbery site (Study 3) are estimated conservatively as: SO 2 = 7.98 µg/m 3 NO 2 = 3.82 µg/m 3 Some boilers on reduced output were operational at all times during the monitoring period. The above levels should therefore be observed as maximums. The background concentrations established during Study 3 were added to the ground level concentrations established during Study 2, see Table 2. Emission Basis of Application SI (µg/m 3 ) Predicted Max GLC (µg/m 3 ) Boilers Only Gas Scenario Oil Scenario Max Background GLC (µg/m 3 ) Predicted Max GLC (µg/m 3 ) Boilers + Background Gas Scenario Oil Scenario NO 2 Annual 40 (30) * Average NO 2 Hourly 200 ** *** *** Average SO 2 24 Hour 125 ** **** **** Average SO 2 Hourly Average 350 ** *** *** Table 2. Reproduction of Table 3 from air dispersion modelling report with additional columns showing predicted maximum ground level concentrations including estimated background levels (for notes applicable to this table see Section 5). The results show that the air dispersion modelling estimates (Study 2) of SO 2 and NO 2 concentrations, including background levels, do not exceed allowable maximum ground level concentrations as detailed in the Air Quality Standards Regulations Discussions and conclusions in the air dispersion modelling report provided in Annex 2 therefore remain valid. The Carbery Group therefore request that IPC Licence 596 is updated to allow the option to use oil as a primary fuel during the months of October to March inclusive starting in Page 4 of 15 EPA Export :18:12:04

5 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 2. Assumptions Various assumptions were made during each of the studies. Specific assumptions are provided in the individual reports. The main assumptions applicable to all studies are detailed here. These assumptions are: Steam consumption rates for the gas and oil scenarios Flue gas flow rates and pollutant concentrations for the gas scenario Flue gas flow rates and pollutant concentrations for the oil scenario Other assumptions, such as flue diameter and stack location coordinates, were available from the Carbery site. 2.1 Steam Consumption Rates for the Oil and Gas Scenarios Current steam consumption for the months of October to March inclusive is known from historical records kept by Carbery and represents the current gas scenario. A steam balance approach was taken for the oil scenario, i.e. the quantity of steam used under the oil scenario is equal to that for the gas scenario. Detailed assumptions are provided in the Study 1 report (see Annex 1 of this report). The tables in Appendices A & B of the Study 1 report clearly show the assumptions used regarding the steam balance. 2.2 Flue Gas Flow Rates and Pollutant Concentrations for the Gas Scenario The values used for the gas scenario are provided in Appendix B of Study 1 (see Annex 1) and page 2 of the air dispersion modelling report (see Annex 2) Flue Gas Flow Rates The flue gas flow rates were obtained from monitoring carried out by Saacke service engineers Flue Gas Pollutant Concentrations The pollutant concentrations were based on historical flue gas analysis results for monitoring required under IPC Licence 596. The relevant page of the IPC Atmospheric Emissions Monitoring Report dated May 2004 has previously been submitted to EPA and provided in Annex Flue Gas Flow Rates and Pollutant Concentrations for the Oil Scenario The values used for the oil scenario are provided in Appendix B of Study 1 (see Annex 1) and page 2 of the air dispersion modelling report (see Annex 2). Note: The calculation inputs for the oil scenario should be considered best estimates from available information. The only reliable method of determining actual pollutant emission concentrations is to carry out a test run using oil while monitoring the flue gas emissions. For the purposes of calculations estimates were made based on the best information available Flue Gas Flow Rates The flue gas flow rates were obtained from information provided by service engineers when the boilers were operated using light oil (September 2000). Page 5 of 15 EPA Export :18:12:05

6 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact Flue Gas Pollutant Concentrations The pollutant concentration estimates used in the calculations are based, where possible, on values obtained from monitoring during a time when the boilers were operated using light oil (September 2000). Available results for boilers 2, 3 and 4 are provided in Annex 5. The emission concentration in Annex 5 are stated in ppm. The steam balance assumes the boilers operating at 50% firing. The relevant results are shown in Table 3 using both ppm and mg/m³ units. SO 2 (ppm) SO 2 (mg/m³) NO x (ppm) NO x (mg/m³) Boiler 2 (A1-2) Boiler 3 (A1-3) Boiler 4 (A1-4) Table 3. Relevant emission concentrations reproduced from Annex 5 for 50% firing 1 2. During September 2000 boiler 1 (A1-2) was not operated and no monitored emission concentrations are available. However, boilers 1 & 2 are identical boilers and burners. It was therefore assumed that emission concentrations would be approximately the same. Boiler 2 is not used within the modelling and calculation scenarios. Emission concentrations used in the modelling and calculations were rounded and generally conservative. With sulphur contents of oils having reduced significantly since 2000 a good margin of error has been allowed for with respect to the SO 2 values. Boiler 5 continues to use biogas under both the oil and gas scenarios. SO 2 and NO x emission concentrations are therefore the same as for the gas scenario within the modelling and calculations. 1 ppm mg/m³ conversion factor (SO 2 273K and standard pressure = ppm mg/m³ conversion factor (NO x as NO 2 273K and standard pressure = 2.05 Page 6 of 15 EPA Export :18:12:05

7 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 3. Estimation of Absolute Pollutant Emissions The Study 1 report is provided in Annex 1. The estimated impact on total pollutant emissions for the period October to March inclusive for the gas and oil scenarios (Study 1) is summarised in Table 4. Gas Scenario Oil Scenario NO x Emissions (tonnes) SO 2 Emissions (tonnes) CO 2 Emissions (tonnes) 24,602 25,100 Table 4. Total estimated pollutant emissions (October to March inclusive) for the gas and oil scenarios. Predicted NO x and SO 2 emissions for the operating period October to March are higher where oil is used as the primary energy source as would be expected. CO 2 emissions are similar under both the gas and oil operating scenarios. Page 7 of 15 EPA Export :18:12:05

8 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 4. Air Dispersion Modelling The Carbery Group commissioned an air dispersion modelling study to assess the impact of the proposed fuel switch on ambient ground level concentrations in the surrounding area. An Air Dispersion Modelling Report, see Annex 2, was submitted to the EPA and a meeting held between the EPA and the Carbery Group in December 2004 to discuss the results of the modelling exercise. Also included is a reference to the model used and its validation, see Annex 3. The results show that the air dispersion modelling estimates (Study 2) of SO 2 and NO 2 concentrations, do not exceed allowable maximum ground level concentrations as detailed in the Air Quality Standards Regulations The EPA requested that the modelled data should include background concentrations for NO 2 and SO 2. Specifically, the EPA requested that Table 3 of the air dispersion modelling report, Annex 2, was updated to include background pollutant concentrations. The air dispersion model did not include background concentrations, e.g. vehicle movements through area and pollution due to other emission sources in the local area. The model specifically calculates pollutant levels due to operational boilers at the site alone. In the absence of reliable data on the background pollutant concentrations in the locality, Carbery commissioned ambient pollution monitoring in order to establish levels with a reasonable degree of certainty. The details of the background monitoring are reported in Section 5 of this report. Page 8 of 15 EPA Export :18:12:05

9 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 5. Results of Background Ambient Air Pollution Monitoring 5.1 General Ambient pollution monitoring for NO, NO 2 and SO 2 was carried out at the boundary of the Carbery site between the 25/1/2005 and 15/2/2005 (21 days total). The monitoring was carried out by Enviro Technology Services Plc (UK). A description of the equipment used and calibration certificates for ambient monitoring are provided in Annex 6. The relative combustion plant and monitor locations are shown in Figure 1. Boilers CHP Monitor Figure 1. Combustion plant and monitor locations at the Carbery site. Monitoring was carried out during this period as the boilers were operating at reduced capacity or not at all during the night and at weekends. This allowed background levels to be identified. The monitors logged 15-minute averaged NO, NO 2 and SO 2 concentrations. Table 5 provides a record of boiler run hours and prevailing wind direction during the period for which ambient air monitoring was carried out. Page 9 of 15 EPA Export :18:12:05

10 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact CHP Boiler 1 Boiler 2 Boiler 3 Boiler 4 Boiler 5 Wind HRS HRS HRS HRS HRS HRS Direction Strength TUES 25/01/ NW Nil WED 26/01/ NW Mod THUR 27/01/ NW Mod FRI 28/01/ NE Mod SAT 29/01/ NE Mod SUN 30/01/ NW Mod MON 31/01/ NW Light TUES 01/02/ N Mod WED 02/02/ W Nil THUR 03/02/ W Mod FRI 04/02/ SW Mod SAT 05/02/ NW Mod SUN 06/02/ NE Nil MON 07/02/ W Mod TUES 08/02/ SW Mod WED 09/02/ SW Mod THUR 10/02/ SW Mod FRI 11/02/ SW Mod SAT 12/02/ W Gale SUN 13/02/ NW Mod MON 14/02/ W Mod TUES 15/02/ NW Nil Table 5. Daily boiler run hours during ambient air monitoring period (shaded yellow boxes indicate boiler co-firing using bio-gas and natural gas). Wind direction was variable during the monitoring period but was predominantly from between the South and North, i.e. blowing approximately in the direction of the ambient monitoring equipment. 5.2 Monitored Data Logged data was provided in parts per billion format. Plots 3 of the monitored data are provided in Figure 2 and Figure 3. Troughs in the data indicate times when the boilers were on low fire or where not all boilers were operational. Red lines indicate a conservative estimate of maximum background concentrations, i.e. generally well above the trough minimums. The red lines conservatively estimate background concentrations as: SO 2 = 3ppb NO 2 = 2ppb The estimated background concentrations were converted to µg/m 3 in order that the units are compatible with the air dispersion modelling report in Annex 2 and limit values from the Air Quality Standards Regulations The original data can be supplied to the EPA on request. The data presented in Figure 2 and Figure 3 are graphical plots of the original data. The following formula was used to convert from ppb to µg/m 3. µg/m 3 = (ppbv)(12.187)(mw) / ( T) where: µg/m 3 = milligrams of gaseous pollutant per cubic meter of ambient air ppbv = parts per billion by volume (i.e., volume of gaseous pollutant per 106 volumes of ambient air) MW = molecular weight of the gaseous pollutant T = temperature of air ( C) 3 Tick marks on the x-axis indicate one day intervals. Tick mark label indicates 00:00 for each day Page 10 of 15 EPA Export :18:12:05

11 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact Pollutant concentrations are based on standard conditions, i.e. 293K, as detailed in the Air Quality Standards Regulations To covert ppb to µg/m 293K the ppb value is multiplied by 2.66 or 1.91 for SO 2 and NO 2 respectively resulting in the following background concentrations. SO 2 = 7.98 µg/m 3 NO 2 = 3.82 µg/m 3 Peaks in ambient SO 2 can be linked with the daily operating hours of boilers co-firing using bio-gas and natural gas, e.g. 4 th & 9 th February. Peaks in ambient NO x can be linked to long daily operating hours of any combination of boiler / CHP plant. Of interest in terms of establishing background concentrations, notably low troughs in ambient air pollutant concentrations, the troughs occur on days when the boiler operation hours are low, e.g. Sunday 6 th February. It could therefore be argued that maximum background concentrations are lower than those estimated by the red lines as some boiler plant is generally operational. The estimated background concentrations should therefore be observed as conservative for the purposes outlined in this report. Page 11 of 15 EPA Export :18:12:05

12 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact SO2 ppb. 24/01/05 25/01/05 26/01/05 27/01/05 28/01/05 29/01/05 30/01/05 31/01/05 01/02/05 02/02/05 03/02/05 04/02/05 05/02/05 06/02/05 07/02/05 08/02/05 09/02/05 10/02/05 11/02/05 12/02/05 13/02/05 14/02/05 15/02/05 16/02/05 17/02/05 Figure 2. Ambient SO2 monitoring results 25/1/05 15/1/05 (red line indicates maximum background for SO2). Page 12 of 15 EPA Export :18:12:05

13 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact NO2 NOx NO ppb. 24/01/ /01/ /01/ /01/ /01/ /01/ /01/ /01/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/ /02/2005 Figure 3. Ambient NOx monitoring results 25/1/05 15/2/05 (red line indicates maximum background for NO2) Page 13 of 15 EPA Export :18:12:05

14 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 5.3 Updated Air Dispersion Modelling Results & Conclusions Table 3 from the air dispersion modelling report, see Annex 2, is reproduced with additional columns showing predicted maximum ground level concentration including background levels, see Table 6. Emission Basis of Application SI 271,2002 (µg/m 3 ) Predicted Max GLC (µg/m 3 ) Boilers Only Gas Scenario Oil Scenario Max Background GLC (µg/m 3 ) Predicted Max GLC (µg/m 3 ) Boilers + Background Gas Scenario Oil Scenario NO 2 Annual 40 (30) * Average NO 2 Hourly 200 ** *** *** Average SO 2 24 Hour 125 ** **** **** Average SO 2 Hourly Average 350 ** *** *** Table 6. Reproduction of Table 3 from air dispersion modelling report with additional columns showing predicted maximum ground level concentrations including estimated background levels. Notes: * For NO 2, 40 refers to annual limit for protection of human health; 30 refers to annual limit for NOx for protection of ecosystems ** see Table 2 of air dispersion modelling report in Appendix A for allowable exceedences and further details *** 98 th percentile modelling data **** 90 th percentile modelling data The results in Table 6 show that the air dispersion modelling results, including background concentrations, do not exceed allowable maximum ground level concentrations under either the gas or oil scenarios. Addition of background concentrations only marginally increases total concentrations. Discussions and conclusions in the air dispersion modelling report provided in Annex 2 therefore remain valid. The monitored results show peaks of up to 50 ppb for both SO 2 and NO 2 for very short periods. This equates to 133 µg/m 3 and 95 µg/m 3 for SO 2 and NO 2 respectively. Although the monitoring represents a snapshot of the entire year it does suggest that annual, 24 hour and hourly averages are lower than the limit values stipulated in the Air Quality Standards Regulations 2002 for the gas scenario. Similar results can be expected under the oil scenario. Page 14 of 15 EPA Export :18:12:05

15 Carbery Group Primary Fuel Switch Proposal Ambient Air Pollution Impact 6. Annexes Page 15 of 15 EPA Export :18:12:05

16 Annex1: Study 1 Assessment of Pollutant Emissions Impact: Fuel Switch Gas Oil (Select Energy Solutions October 2004) EPA Export :18:12:05

17 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil CARBERY GROUP Reference Nr: A Assessment of Pollutant Emissions Impact Fuel Switch Gas - Oil Prepared by: Andrew Shepherd Select Energy Solutions Silverhill Ballyderown Kilworth County Cork andrew.shepherd@select-energy-solutions.net Tel. (0) M Date of issue: 15 th October 2004 Page 1 of 10 EPA Export :18:12:05

18 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil Table of contents 1 Management Summary Purpose & Approach Assumptions Current & Predicted Emissions Appendices... 7 Page 2 of 10 EPA Export :18:12:05

19 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil 1 Management Summary For economic and security of supply reasons, the Carbery Group propose switching, or to have the option of switching, from natural gas to oil as a primary energy source for a large proportion of their steam production requirements at the Ballineen factory in West Cork during the period October to March inclusive. Five conventional boilers and one CHP plant are currently used to provide factory steam requirements. Currently, all steam raising plant uses gas (natural gas and biogas) as its primary energy source, i.e. gas scenario. Calculations have been carried out to estimate the impact of pollutant emissions of providing a significant proportion of steam requirements from oil fired plant. The proposed oil scenario uses oil in boiler 1, 2, 3 and 4, gas in boiler 5 and does not operate the CHP plant at all. This represents an extreme scenario. For practical and operational reasons, Carbery may operate somewhere between the two scenarios considered. Calculations are based on a steam balance, i.e. factory steam requirements under both scenarios are equal. For the purposes of the assessment, 260,000,000 lb of steam are required for the operating period under consideration. This represents an estimate of steam consumption under current operating conditions. Pollutant emissions under the two alternative operating scenarios are provided in Table 1. Gas Scenario Oil Scenario NOx Emissions (tonnes) SO 2 Emissions (tonnes) CO 2 Emissions (tonnes) 24,602 25,100 Table 1. Pollutant emissions for the operating period October March inclusive. Predicted NOx and SO 2 emissions for the operating period October to March are higher where oil is used as the primary energy source. CO 2 emissions are similar under both the gas and oil operating scenarios. Page 3 of 10 EPA Export :18:12:05

20 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil 2 Purpose & Approach For economic and security of supply reasons, the Carbery Group propose switching, or to have the option of switching, from natural gas to oil as a primary energy source for a large proportion of their steam production at the Ballineen factory in West Cork during the period October to March inclusive. Select Energy Solutions were requested to carry out an assessment of environmental pollutant emissions impact of the proposed fuel switch. Current emissions from the gas fired plant have been compiled from monitored results of actual plant energy consumption and emissions. Predicted emissions for operation of the plant using oil as the primary fuel are based on the best available data from engineers responsible for the maintenance of the plant and burner manufacturer s data. Emissions resulting from the use of oil as a primary fuel can only be confirmed by direct monitoring of the energy using plant. Select Energy Solutions are of the opinion that the predicted emissions from the use of oil provide the best available information in the absence of monitored data. The figures presented in this report represent an extreme case scenario. The oil based operating scenario calculations assume that the CHP plant is not operated and the majority of steam for the factory is provided by boilers 1, 2, 3 and 4 using oil (boiler 5 is operated using biogas and natural gas under both scenarios). In practice, both oil and gas may be used in some combination resulting in emission figures lying between those calculated under each of the presented operating scenarios. 3 Assumptions In carrying out the assessment the following assumptions have been made: All steam boiler burners are modulating. All emissions data and run hours are based on the boilers running at 50% full load. This is the most common, and preferred, operating capacity of the boilers for reasons of energy efficiency and providing a capability for meeting plant demand satisfactorily at the Carbery plant. Current energy using plant run hours are based on the knowledge of the facilities engineer. Predicted energy using plant run hours are based on the predictions of the facilities engineer Boiler 5 continues to use biogas and natural gas under both the gas and oil scenarios Light Fuel (LF) oil = 67%/33% mix Heavy Fuel Oil / Light Fuel Oil Page 4 of 10 EPA Export :18:12:05

21 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil 4 Current & Predicted Emissions The calculations are based on an energy balance, i.e. Current Steam Production (Gas Scenario) = Predicted Steam Production (Oil Scenario) for the period October to March inclusive. The current steam consumption on site is c. 260,000,000 lb steam during the period in question. An equivalent quantity of steam has been used for the energy balance with oil as the main primary energy source. Detailed calculations for operating the plant using gas and oil are presented in Appendix A and Appendix B respectively. Appendix C shows CO 2 emission factors calculations. Summarised pollutant emissions for the operating period October to March inclusive are provided in Table 2. Gas Scenario Oil Scenario NOx Emissions (tonnes) SO 2 Emissions (tonnes) CO 2 Emissions (tonnes) 24,602 25,100 Table 2. Pollutant emissions for the operating period October March inclusive. The results presented in Table 2 are shown graphically in Figure 1 and Figure 2. Tonnes NOx & SO2 Emmissions (October - March Inclusive) NOx SO2 0 Gas Oil Figure 1. NOx & SO 2 emissions for gas and oil steam production October to March inclusive. Page 5 of 10 EPA Export :18:12:05

22 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil CO2 Emissions (October - March Inclusive) 30,000 25,000 24,602 25,100 Tonnes 20,000 15,000 10,000 5,000 0 Gas Oil Figure 2. CO 2 emissions for gas and oil steam production October to March inclusive. Predicted NOx and SO 2 emissions for the operating period October to March are higher where oil is used as the primary energy source. CO 2 emissions are similar under both the gas and oil operating scenarios. Although oil produces higher CO 2 emissions per unit of energy consumed, this is offset by a reduction in CHP electricity production emissions due to the CHP not being operated under the oil scenario. Page 6 of 10 EPA Export :18:12:05

23 5 Appendices Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil Page 7 of 10 EPA Export :18:12:05

24 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil Appendix A: Gas Pollutant Emission Calculations Boiler OutputDischarge rate SO 2 DischargeNO x DischargeCO 2 DischargePredicted run Estimated SO 2 Estimated NO x Estimated CO 2 Steam Output% Full Boiler Capacity Nm3/hr (mg/nm3) (mg/nm3) Kg/hr Time Hrs Emissions Emissions Emissions lb/period Capacity Lbs/hr Gas Gas 596 limit Gas 596 limit Gas (tonnes) (tonnes) (tonnes) Boiler 1 45,000 51, , % Boiler 2 45,000 51, , % Boiler 3 25,000 29, % Boiler 4 35,000 40, , % Boiler 5 31,500 40, , CHP SF 34,000 31, ,368 CHP TEG 27,500 25, ,667 4,368 1,222 4, ,024 64,732, % 0 8 3,560 74,256, % , ,120, % Totals Heat 12, , ,108,500 Notes on data source: Boiler Output Capacity: manufacturers data / Carbery monitored data Discharge Rate monitored using pitot tube method: Environmental Impact Statement 2000 prepared by E.G. Pettit & Co previously submitted to EPA SO 2 / NOx Discharge Rate: monitored using flue gas analyser submitted to EPA as part of bi-annual IPC monitoring requirement Run Hours: historical plant monitoring Steam Output: based on plant operating at a percentage of full capacity on average % Full Boiler Capacity knowledge of Carbery facilities engineer TEG = Thermal Exhaust Gas SF = Supplementary Firing Page 8 of 10 EPA Export :18:12:05

25 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil Appendix B: Oil Pollutant Emission Calculations Boiler OutputDischarge rate SO 2 DischargeNO x DischargeCO 2 DischargePredicted run Estimated SO 2 Estimated NO x Estimated CO 2 Steam Output% Full Boiler Capacity Nm3/hr (mg/nm3) (mg/nm3) Kg/hr Time Hrs Emissions Emissions Emissions lb/period Capacity Lbs/hr LFO LFO 390 limit LFO 390 limit LFO (tonnes) (tonnes) (tonnes) Boiler 1 45,000 49, , ,204 Boiler 2 45,000 49, ,700 Boiler 3 25,000 28, , Boiler 4 35,000 39, , Boiler 5 31,500 42, , , ,464 86,400, % , % 1,259 2, ,771 27,500, % 1,952 4, ,527 76,440, % 1,222 4, ,338 68,796, % CHP SF 34,000 31, % CHP TEG 27,500 25, % Notes on data source: Boiler Output Capacity: manufacturers data / Carbery monitored data Total 14, , ,136,000 Discharge Rate: manufacturers data / commissioning & service engineers best estimation SO 2 / NOx Discharge Rate: manufacturers data / commissioning & service engineers best estimation Run Hours: plant operation hours based on hours required to supply equivalent quantities steam as for all gas operation Steam Output: based on plant operating at a percentage of full capacity on average % Full Boiler Capacity knowledge of Carbery facilities engineer TEG = Thermal Exhaust Gas SF = Supplementary Firing Page 9 of 10 EPA Export :18:12:06

26 Assessment of Pollutant Emissions Impact: Fuel Switch Gas - Oil Appendix C: Emission Factors CO 2 Gas flow rate Oil flow rate CO 2 Discharge CO 2 Discharge NM3/hr lts/hr Kg/hr Kg/hr Boiler ,426 2,204 Boiler ,426 2,204 Boiler ,259 Boiler ,263 1,952 Boiler ,222 0 CHP SF CHP TEG 1, ,667 0 TEG = Thermal exhaust gas (from electrical turbine) SF = Supplementary Firing Gas LF Oil (67/33) Fuel emissions factor Net Calorific Value kwh x x 3.6E Oxidation Factor M 3 /Lt - kwh Kg CO 2 per M 3 / Lt Gas LFO 1 Based on EPA values Page 10 of 10 EPA Export :18:12:06

27 Annex 2: Study 2 Air Dispersion Modelling Report Air Pollution Modelling Report (SWS Group December 2004) EPA Export :18:12:06

28 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling AIR POLLUTION MODELLING CARBERY MILK PRODUCTS LIMITED BALLINEEN CO. CORK SWS Environmental Services SWS ENVIRONMENTAL SERVICES SHINAGH HOUSE BANDON CO. CORK EPA Export :18:12:06

29 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling Document Control Sheet SWS Environmental Services Client: Carbery Milk Products Document Brief Report type (draft or final) Final Copies Mr Pat O Mahony Environmental Manager Carbery Milk Products Ltd Report from: Cyril Tynan Environmental Consultant SWS Environmental Services Declan Waugh Senior Environmental Consultant SWS Environmental Services Report Issue Date 6 th December 2004 SWS Environmental 2004_171 Report Brief Ref. Revision Prepared Checked Approved Date No Copies Number by: by: by: 0 CT/DW DW DW 06/12/04 3 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:06

30 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling TABLE OF CONTENTS Executive Summary 1.0 INTRODUCTION 2.0 METHODOLOGIES 3.0 RESULTS 4.0 CONCLUSION SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:06

31 Executive Summary Carbery Milk products Limited requested SWS Environmental Services to examine the environmental consequences of changing the fuel type of a number of their boilers on site. Proposed emission data was examined for oil and gas options. Dispersion modelling was conducted using the worst case scenario for both options to examine the potential ground level concentrations of pollutants. Concentrations were plotted over a number of averaging periods (hourly, daily, annually) in order that they may be compared with standards as specified in the Air Quality Standards Regulations Dispersion modelling results indicate that all predicted ground level concentrations in the area surrounding the plant and at all residences within a 10 km radius are well within current air quality standards. 1.0 INTRODUCTION SWS Environmental services were requested to undertake atmospheric dispersion modelling for Carbery Milk Products Limited, Balineen, Co Cork. As a consequence of escalating fuel costs Carbery Milk Product Ltd are examining the possibility of converting fuel sources for a number of boilers on site. Air dispersion modelling was conducted to evaluate the impact of stack emissions in terms of maximum predicted ground level concentrations. Two fuel types were examined for a number of boilers, and emission data was obtained for each of the proposed systems. Results were compared to current air quality standards in Ireland; Air Quality Standards Regulations 2002 (S.I. No 271 of 2002) in order to determine if the development could have any impacts on human health and the environment. 2.0 METHODOLOGIES The concentration of pollutants around the stacks was modelled using the hourly meteorological data of the year 2001 observed in Cork. This dataset was examined and compared with the monthly averages wind speed and temperature during the years SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:06

32 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 1991 at this site (Figure 1) and found to be comparable. The emission data used of for each of the two scenarios were as follows: Table 1a Anticipated Emission Levels Gas Scenario GAS SCENARIO CHP Boiler no.5 Fuel Nat Gas Biogas / Nat Gas Easting in m Northing in m Exit temperature in K Flue gas flow rate in STP ,200 Flue gas flow rate in m³/s Exit velocity in m/s Stack height SO2 STP NOx STP Table 1b OIL SCENARIO Anticipated Emission Levels Oil Scenario Boiler no.1 Boiler no.3 Boiler no.4 Boiler no.5 Fuel Oil Oil Oil Biogas / Nat Gas Easting in m Northing in m Exit temperature in K Flue gas flow rate in STP 49,015 28,350 39,690 42,200 Flue gas flow rate in m³/s Exit velocity in m/s Stack diameter Stack height SO 2 STP NOx STP Both oil and gas scenarios were modelled using the source emission data, modelling was undertaken in the scenario where the boilers are operating simultaneously over the one year period (without taking into account the operating hours). The air pollutant dispersion modelling was performed with an advanced Gaussian plume model that uses similarity theories to determine wind turbulence properties. 2 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:06

33 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling The hourly and daily predictions are accounting for those days and times that all boilers are in operation, while the yearly averages are also most conservative (worst case scenarios) for comparison with the current legislative standards. Air Quality Standards Regulations, 2002 Air quality control and assessment in Ireland is provided for under the Air Quality Standards Regulations 2002 (S.I. No. 271 of 2002). Assessment thresholds (upper and lower) are defined for the assessment and management of air quality in zones, limit values together with margins of tolerance specified with target limit values to be achieved over a defined timeframe. Hourly, daily and annual limits are specified for many of the parameters for the protection of human health, vegetation and ecosystems. Table 2 presents a summary of the air quality standards applicable in Ireland are contained in Table 2. Table 2 Limit Values from Air Quality Standards Regulations, 2002 Pollutant SO 2 SO 2 Limit Value Objective Protection of human health Protection of human health Averaging Period Limit Value µg/m 3 1 hour hours 125 Basis of Application of the Limit Value Not to be exceeded more than 24 times in a calendar year. Not to be exceeded more than 3 times in a calendar year. Limit Value Attainment Date 1/1/2005 1/1 /2005 SO 2 Protection of ecosystems Calendar year 20 Annual mean. 19/7/2001 SO 2 Protection of ecosystems 1 Oct to 31 Mar 20 Winter mean. 19/7/2001 NO 2 Protection of human health 1 hour 200 Not to be exceeded more than 18 times in a calendar year. 1/1/2010 NO 2 Protection of human health Calendar year 40 Annual mean. 1/1/2010 NO + NO 2 Protection of vegetation Calendar year 30 Annual mean. 19/7/ SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:06

34 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 3.0 RESULTS The concentration of pollutants was plotted based on meteorological data presented in Figures 1 and 2. Contour plots of maximum ground level concentrations occurring are presented in Figures 3 to 6 for the gas option and Figures 7 to 10 for the oil option. Maximum predicted ground level concentrations are for each scenario are summarised in Table 3 and compared to relevant legislative standards. Since air quality objectives are expressed in a variety of averaging periods, modelling results are presented in a similar manner with hourly average, daily average and annual average concentrations calculated as appropriate. Percentiles of hourly and daily averages were also calculated. Table 3 Predicted Maximum GLCs Emission Basis of Application SI 271, 2002 (µg/m 3 ) Predicted Max GLC Concentrations (µg/m 3 ) GAS SCENARIO OIL SCENARIO NO 2 Annual Average 40 (30) * NO 2 Hourly Average 200** *** *** SO 2 24 hour 125** 11.92**** 29.65**** SO 2 Hourly Average 350** 65.46*** 177.8*** Notes: *For NO 2, 40 refers to annual limit for protection of human health; 30 refers to annual limit for NOx for protection of ecosystems. ** See Table 2 for allowable exceedences and further details. *** 98 th percentile modelling data. **** 90 th percentile modeling data 2.0 DISCUSSION Statistics on the wind direction show that the pollutants will be dispersed most of the time on the South-East and North-East of the plant and the highest concentrations will be experienced within a 1km radius of the plant boundary. 4 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:07

35 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling The nearest 4 residences to the main plant are within a 200m radius of the main plant. These residences are situated two to the east and two to the west of the main plant and dispersion plots indicate that they are not within the areas of maximum predicted ground level concentrations. Three further residences situated to the North- West of the plant are situated in the direction of the southeast wind but at a distance of approximately 1km. At this distance, contour plots indicate that concentrations will have dispersed to well below maximum ground level concentrations. Dispersion modelling predicts that ground level concentrations of the pollutants will be well below the current air quality standards / guidelines of the Irish and European legislation for both oil and gas scenarios. 3.0 CONCLUSION The maximum predicted ground level concentrations are significantly lower than the air quality standards as specified in the Air Quality Regulation SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:07

36 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 8 7 Mean wind speed Mean wind speed 2001 Mean temperature Mean temperature Mean wind speed [m/s] Mean temperature [degree Celsius] January February March April May June July August September October November December 0 Month Figure 1 Meteorological Data for and SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:07

37 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 9% 8% 7% > 9 m/s 7-9 m/s 5-7 m/s 3-5 m/s 1-3 m/s < 1 m/s Average wind speed 7 6 Frequency 6% 5% 4% 3% 2% 1% Average wind speed in m/s 0% Wind direction from North in degrees 0 Figure 2 Windspeed and Heading 7 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:07

38 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 8 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

39 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 9 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

40 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 10 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

41 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 11 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

42 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 12 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

43 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 13 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

44 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 14 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:08

45 Client: Carbery Milk Products Ltd Ref Number:2004_171 Report: Air Dispersion Modelling 15 SWS Environmental Services, Shinagh House, Bandon. EPA Export :18:12:09

46 Annex 3: Dispersion Model Validation The Carbery Group submitted an Air Dispersion Modelling report to the EPA in December The EPA requested further information on the validity of the modelling software used. The model used is an Advanced Gaussian Plume. An extract from a report submitted to the EPA in 2002 describes the validation of the model used compared to the ISC2 model (the US EPA recommended regulatory model). The Advanced Gaussian Plume air dispersion model has previously been accepted by the EPA with respect to reports submitted for modelling at the Carbery and other sites by the SWS Group. EPA Export :18:12:09

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54 Annex 4: Flue Gas Pollutant Monitoring Results for Gas IPC Atmospheric Emissions Monitoring Report May 2004 (relevant page). EPA Export :18:12:10

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56 Annex 5: Flue Gas Pollutant Monitoring Results for Light Oil (September 2000) Available reports for boilers 2, 3 and 4 by Enviro Technology Services Plc. EPA Export :18:12:10

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60 Annex 6: Enviro Tech Ambient Monitoring Equipment Description & Calibration Description Item Description 1 ET M200E Chemiluminescent real-time NOx analyser to include: Internal zero span system for automatic calibration checking NO 2 permeation tube for above Internal large capacity data storage Suitable for urban, roadside & kerbside monitoring Full microprocessor control AEA NETCEN approved for use on the UK AUN Network US EPA approved reference method 2 ET M100E UV Fluorescent real-time SO 2 analyser to include: Internal zero span system for automatic calibration checking SO 2 permeation tube for above Internal large capacity data storage Suitable for urban, roadside & kerbside monitoring Full microprocessor control AEA NETCEN approved for use on the UK AUN Network US EPA approved reference method 3 ET M-Type weatherproof enclosure to include: Dimensions 745 mm (d) x 1065 mm (w) x 1275 mm (h) side mounted air conditioning unit and cover Internal shelving Mesh cage for protection of sampling system Easy to transport, no planning permission Anti-vandal construction EPA Export :18:12:10

61 SO 2 Calibration Serial No: G.m.t. Fault Message: None API M100 / A DATA SHEET ET No: PRE TEST DATA POST TEST DATA Time: G.m.t. Range: 1000 Units: ppb Stabil: 2.5 Press: 26.5 Sample Flow: 6.9 PMT: UV Lamp: 3620 UV Lamp Ratio: 90.1 Stray Light: 42.2 Drk PMT: 80.2 Drk Lmp: 6.9 Slope: Offset: 85.1 HVPS: 633 DCPS: 2556 Rcell Temp: 50 Box Temp: 23.8 PMT Temp: 7.8 IZS Temp: 50 Units IN-Hg-A cc/min mv mv % units mv mv mv V mv C C C C Time: G.m.t. Range: Units: 1000 ppb Stabil: 109 Units Press: 24.6 IN-Hg-A Sample Flow: 572 cc/min PMT: mv UV Lamp: 3619 mv UV Lamp Ratio: 89.1 % Stray Light: 42.2 units Drk PMT: 53.8 mv Drk Lmp: 9.6 mv Slope: Offset: 85.1 mv HVPS: 633 V DCPS: 2558 mv Rcell Temp: 50 C Box Temp: 23.8 C PMT Temp: 7.8 C IZS Temp: 50 C ZERO TESTS Functions OK: AMX Software configured: Remote Zero Tested: Remote Span Tested: RS232 Comms Tested: Status Outputs Tested: Check appropriate boxes when tasks are complete TESTS Functions OK: AMX Software configured: Remote Zero Tested: Remote Span Tested: RS232 Comms Tested: Status Outputs Tested: Check appropriate boxes when tasks are complete Model: 100A Serial No: G.m.t. ET No: RANGE DISPLAY (ppb) VOUT (mv) 1000 Pre-Service/ Repair Calibration Zero Source Details Scrubber Canister : Yes Contents of Scrubber: Charcoal No 0 0 Span Source Details SPAN Cyl. No: Cyl. Press: Cyl. Conc: Blender: Cyl. Flow: DIL Flow: HighConc. Cyl. ppm: Blender Output: Yes No Post Service/Repair Calibration ZERO RANGE DISPLAY (ppb) VOUT (mv) Zero Source Details Yes No Scrubber Canister : Contents of Scrubber: Charcoal Span Source Details SPAN Cyl. No: 0 Cyl. Press: 140 Cyl. Conc: 0 Yes Blender: Cyl. Flow: 0 DIL Flow: 0 HighConc. Cyl. ppm: n/a Blender Output: n/a No EPA Export :18:12:10

62 NO x Calibration API M200/A DATA SHEET Serial No: Fault Message: None ET No: PRE TEST DATA POST TEST DATA Time: Time: Range: 1000 Range: 1000 Units: Units: Noise: Sample Flow: Ozone Flow: PMT: Norm PMT: Azero: HVPS: DCPS: Rcell Temp: Box Temp: PMT Temp: IZS Temp: Moly Temp: C Moly Temp: RCEL: SAMP: NOx Slope: NOx Offs: -2.6 mv NOx Offs: -2.6 mv NO Slope: GMT ppb Noise:.3 Units Sample Flow: 449 Ozone Flow: 79 PMT: 16.6 mv Norm PMT: -5.7 mv Azero: 14 HVPS: 688 V DCPS: 2543 mv Rcell Temp: 49.9 C Box Temp: 20.9 C PMT Temp: 7.6 C IZS Temp: 49.9 C RCEL: 6.0 SAMP: 29.1 NOx Slope: cc/min cc/min NO Slope: NO Offs -3.3 mv NO Offs -3.3 mv TESTS Functions OK: TESTS Functions OK: AMX Software configured: AMX Software configured: Remote Zero Tested: Remote Zero Tested: Remote Span Tested: Remote Span Tested: RS232 Comms Tested: RS232 Comms Tested: Status Outputs Tested: Status Outputs Tested: mv IN-Hg-A IN-Hg-A Check appropriate boxes when tasks are complete GMT ppb Units cc/min cc/min mv mv mv V mv C C C C C IN-Hg-A IN-Hg-A Check appropriate boxes when tasks are complete Model: 200A Serial No: Pre-Service/Repair Gas Tests ET No: Span Point Range Display Vout Diluent Flow Cyl. Flow Span Gas (ppb) 1A B (GPT) ZERO 1000 Zero Scrubber Used? Contents of Scrubber? NO NOx NO NOx NO NOx NO NOx NO NOx NO NOx NO NOx Click here if used Ambient Gas Cyl. Used? GPT 03 Conc(1B): Charcoal/Purafil Cyl. No: 0 Cyl. Press: 0 Molybdenum Converter Efficiency: not tested % Cyl. Conc: Click here if used #DIV/0! - Post-Service/Repair Gas Tests Display Vout Span Point Range Diluent Flow Cyl. Flow - NO - - 1A NOx NO B (GPT) NOx NO NOx NO NOx NO NOx NO NOx NO ZERO 1000 NOx Click here if used Click here if used Zero Scrubber Used? Ambient Gas Cyl. Used? GPT 03 Conc(1B): 0 Contents of Scrubber? Charcoal/Purafil Cyl. No: FF4949 Cyl. Press: 135 Molybdenum Converter Efficiency: see pre-service tests % Cyl. Conc: 524 Span Gas (ppb) EPA Export :18:12:10