APPENDIX I Air Quality Technical Data Report. PDF Page 1 of 117

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1 APPENDIX I Air Quality Technical Data Report PDF Page 1 of 117

2 PDF Page 2 of 117 Air Quality Technical Data Report Prepared for: NOVA Gas Transmission Ltd. Calgary, Alberta Prepared by: Stantec Consulting Ltd. Calgary, Alberta

3 PDF Page 3 of 117 AIR QUALITY TECHNICAL DATA REPORT Table of Contents EXECUTIVE SUMMARY... V ABBREVIATIONS... VII 1.0 INTRODUCTION TDR OBJECTIVES SUBSTANCES OF INTEREST OXIDES OF NITROGEN RESPIRABLE PARTICULATE MATTER CARBON MONOXIDE AMBIENT AIR QUALITY OBJECTIVES AND STANDARDS REGIONAL SETTING STUDY AREA TOPOGRAPHY CLIMATE Temperature Precipitation Humidity Winds BASELINE AIR QUALITY Oxides of Nitrogen and Nitrogen Dioxide Respirable Particulate Matter Carbon Monoxide SUMMARY MODELLING METHODOLOGY AERMOD DISPERSION MODEL DISPERSION METEOROLOGY RECEPTOR GRIDS AND TERRAIN BUILDING DOWNWASH EFFECTS NOX TO NO2 CONVERSION EXISTING INDUSTRIAL SOURCES AND BACKGROUND AIR QUALITY MODELLING SCENARIOS EMISSION RATES Project Air Emission Sources Regional Air Emission Sources DISPERSION MODELLING RESULTS BASELINE CASE PROJECT ONLY CASE APPLICATION CASE i

4 PDF Page 4 of 117 AIR QUALITY TECHNICAL DATA REPORT 6.0 GREENHOUSE GASES EMISSIONS OF GHGS PROPOSED PROJECT SENSITIVITIES TO CLIMATE CHANGE SUMMARY AND CONCLUSIONS REFERENCES LIST OF TABLES Table 2-1 Provincial and National Ambient Air Quality Objectives and Standards Table 3-1 Geographic Coordinates of Stations Used in the Climate Analysis Table 3-2 Seasonal and Mean Daily Temperatures Wonowon and Fort St. John CCNS Table 3-3 Rainfall, Snowfall, and Total Precipitation at the Wonowon CCNS Table 3-4 Rainfall, Snowfall, and Total Precipitation at the Fort St. John CCNS Table 3-5 Historical Monthly Mean Relative Humidity at the Fort St. John Airport CCNS Table 3-6 Summary Statistics for WRF-Derived Wind Data Table 3-7 Continuous Ambient Air Quality Monitoring Stations Used in the Baseline Air Quality Analysis Table 3-8 Data Periods for Continuous Ambient Air Quality Monitoring Stations Used in the Baseline Air Quality Analysis Table 3-9 Summary of Continuous Ambient Air Quality Monitoring Data at Stations Used in the Baseline Air Quality Analysis Table 4-1 Buildings and Structures Considered in Dispersion Modelling (Aitken Creek Compressor Station) Table 4-2 Buildings and Structures Considered in Dispersion Modelling (Saturn 1 Compressor Station) Table 4-3 Stack and Emission Parameters Applied in Dispersion Modelling for Project Sources (Aitken Creek Compressor Station) Table 4-4 Stack and Emission Parameters Applied in Dispersion Modelling for Project Sources (Saturn 1 Compressor Station) Table 4-5 Summary of Regional Background Facilities Included in Dispersion Modelling Table 4-6 Summary of Regional Background Facilities Included in Dispersion Modelling Table 5-1 Maximum Predicted Ground-level Concentrations Associated with the Baseline Case (Aitken Creek Compressor Station) Table 5-2 Maximum Predicted Ground Level Concentrations for NO2, CO and PM2.5 for the Project Only Case (Aitken Creek Compressor Station) ii

5 PDF Page 5 of 117 AIR QUALITY TECHNICAL DATA REPORT Table 5-3 Maximum Predicted Ground Level Concentrations for NO2, CO and PM2.5 for the Project Only Case (Saturn 1 Compressor Station) Table 5-4 Maximum Predicted Ground Level Concentrations for NO2, CO and PM2.5 for the Application Case (Aitken Creek Compressor Station) Table 6-1 Project GHG Emissions Table 6-2 Greenhouse Gas Emissions: Canada and British Columbia Table 6-3 Proposed Facility Sensitivities to Direct and Indirect Climate Influences LIST OF APPENDICES APPENDIX A REPORT FIGURES... A.1 APPENDIX B CLIMATE AND METEOROLOGY OF THE STUDY AREA... B.1 B.1 Introduction... B.1 B.2 Climate and Meteorology... B.2 B.2.1 Ambient Temperature... B.2 B.2.2 Wind... B.3 B.2.3 Atmospheric Stability... B.7 B.2.4 Mixing Height... B.9 APPENDIX C DISPERSION MODELLING ISOPLETH MAPS... C.1 iii

6 PDF Page 6 of 117 AIR QUALITY TECHNICAL DATA REPORT Executive Summary Stantec Consulting Ltd. (Stantec) was contracted by NOVA Gas Transmission Ltd. (NGTL), a wholly owned subsidiary of TransCanada PipeLines Limited (TransCanada), to conduct an air quality assessment to support the regulatory application for the North Montney Project (the Project). The Project involves the construction and operation of pipeline, temporary and permanent facilities in the North Montney area of British Columbia (BC). This technical data report (TDR) describes a dispersion assessment conducted in support of the NGTL s.52 Application to the National Energy Board (NEB). The Project will involve the construction and operation of 306 km of pipeline, metering and interconnection facilities, tie-in facilities, compressor stations, mainline valve sites, launcher and receiver facilities and cathodic protection facilities. The majority of the air emissions related to the operation of the Project will result from the operation of the compressor stations. The air emission sources in these facilities comprise compressor turbines, boilers and generators. At the time of preparing this TDR, the proposed Project comprised only the Aitken Creek and Saturn 1 compressor stations. Since beginning the application and approvals process, there has been an additional compressor unit added to Saturn 1 (referred to as Saturn 2), and an additional compressor station (Groundbirch) added to the Project. Due to their recent addition to the Project, an analysis of the emissions from the Saturn 2 and Groundbirch compressor stations will follow a similar analysis as presented in the current TDR, and the results of that analysis are scheduled to be submitted as a supplemental filing in March The following cases are, therefore, considered in this technical data report: Baseline Case: includes emissions from the nearby facilities alone Project Case: includes emissions from the operation of the proposed Aitken Creek and Saturn 1 compressor stations Application Case: includes emissions from the Baseline Case and the Project Case In each case, the maximum concentrations of NO 2, PM 2.5 and CO, including representative background concentrations, are predicted to fall below the applicable ambient air quality objectives. Annual greenhouse gas (GHG) emissions from operation of the proposed units, expressed as carbon dioxide equivalent (CO 2 eq) emissions, represent 0.02% of the Canadian total emissions for 2011, and 0.23% of the British Columbia total emissions for The 2011 emissions data represent the most recent, reviewed data available at the time of this assessment. Mitigation and adaptive management measures will be designed into the proposed compressor units where economically reasonable, to further reduce potential effects on air quality. v

7 PDF Page 7 of 117 AIR QUALITY TECHNICAL DATA REPORT Abbreviations % percent C degrees Celsius µg/m 3 microgram per cubic metre µm micrometre or micron AAQO Ambient Air Quality Objective AERMAP terrain pre-processor for AERMOD AERMET meteorological data pre-processor for AERMOD AERMOD plume dispersion model BC British Columbia BC HLS British Columbia Ministry of Healthy Living and Sport BC MOE British Columbia Ministry of Environment CASA Clean Air Strategic Alliance CCME Canadian Council of Ministers of Environment CCNS Canadian Climate Normal Station CEA Agency Canadian Environmental Assessment Agency CH4 methane cm centimetre CO carbon monoxide CO2 carbon dioxide CO2 eq carbon dioxide equivalents CWS Canada-Wide Standard g/s grams per second GHG greenhouse gas H2S hydrogen sulphide K degrees Kelvin km kilometre km/h kilometres per hour LST Local Standard Time m metres m asl metres above sea level m/s meter per second me metres east mm millimetres MM5 Mesoscale Model v5 MMIF Mesoscale Model Interface Program mn metres north vii

8 PDF Page 8 of 117 AIR QUALITY TECHNICAL DATA REPORT N N/A N2O NAAQO NAD NCAR NEB NGTL NO NO2 NOX PM10 PM2.5 SO2 t/y TDR TSP U.S. EPA UTM WRAP WRF north not appicable nitrous oxide National Amabient Air Quality Objectives North American Datum National Centre for Atmospheric Research National Energy Board NOVA Gas Transmission Ltd. nitric oxide nitrogen dioxide nitrogen oxides inhalable particulate matter respirable particulate matter sulphur dioxide tonnes per year technical data report total suspended particulates United States Environmental Protection Agency Universal Transverse Mercator Western Regional Air Partnership Weather Research and Forecasting viii

9 PDF Page 9 of 117 AIR QUALITY TECHNICAL DATA REPORT Introduction 1.0 Introduction Stantec Consulting Ltd. (Stantec) was contracted by NOVA Gas Transmission Ltd. (NGTL), a wholly owned subsidiary of TransCanada PipeLines Limited (TransCanada), to conduct an air quality assessment to support the regulatory application for the North Montney Project (the Project). The Project involves the construction and operation of pipeline, temporary and permanent facilities in the North Montney area of British Columbia (BC). This technical data report (TDR) describes a dispersion assessment conducted in support of the NGTL s.52 Application to the National Energy Board (NEB). The Project will involve the construction and operation of 306 km of pipeline, metering and interconnection facilities, tie-in facilities, compressor stations, mainline valve sites, launcher and receiver facilities and cathodic protection facilities. The majority of the air emissions related to the operation of the Project will result from the operation of the compressor stations. The air emission sources to be incorporated into the design of the facilities are compressor turbines, boilers and generators. At the time of preparing this TDR, the Project consisted of only the Aitken Creek and Saturn 1 compressor stations. Since beginning the application and approvals process, there has been an additional compressor unit added to Saturn 1 (referred to as Saturn 2), and an additional compressor station (Groundbirch) added to the Project. Emissions from the Saturn 2 and Groundbirch compressor stations are not included in this assessment, but will follow a similar analysis as presented in the current TDR. The results of that analysis are scheduled to be submitted as a supplemental filing in March There are no permanent residences within 2 km of either the Aitken Creek or Saturn 1 compressor stations. The nearest resident to the proposed Aitken Creek compressor station is located approximately 2.5 km north of the site. The nearest resident to the proposed Saturn 1 compressor station is located approximately 9.5 km north northeast of the site. To evaluate the air quality effects associated with emissions from the Aitken Creek and Saturn 1 compressor stations, ground-level concentrations were predicted through mathematical dispersion modelling. Dispersion modelling was conducted in accordance with the Guidelines for Dispersion Modelling in BC (BC MOE 2008) and predicted ground-level concentrations were compared to the relevant ambient air quality criteria to assess compliance. Project emissions during normal conditions were modelled and other sources of air emissions in the region were also considered. The secondary focus of this TDR concerns the emissions of greenhouse gases (GHGs), which are assessed consistent with Canadian Environmental Assessment Agency (CEA Agency 2003) guidance. This report also includes a description of existing climatic and air quality conditions near the Project. 1.1

10 PDF Page 10 of 117 AIR QUALITY TECHNICAL DATA REPORT Introduction 1.1 TDR OBJECTIVES The purpose of this TDR is to describe the methodologies and technical details related to the air quality assessment for the Project. Information has been generated from existing literature and technical data sources, engineering estimates and computer dispersion modelling. This TDR presents the following key information: 1. a listing of substances of interest in the air quality assessment 2. a discussion of the study area, its climate, and air quality baseline conditions 3. a summary of air quality dispersion modelling methods, modelling scenarios and emission estimates 4. a summary of air quality dispersion modelling results, and 5. an assessment of greenhouse gases (GHGs) consistent with CEA Agency (2003) guidance. 1.2

11 PDF Page 11 of 117 AIR QUALITY TECHNICAL DATA REPORT Substances of Interest 2.0 Substances of Interest For this assessment, oxides of nitrogen (NO X), fine particulate matter (PM 2.5) and carbon monoxide (CO) were selected as the key substances of interest with respect to air emissions from the Project. Most of the project sources emit these substances, which are common by-products of combustion. Emissions of sulphur dioxide (SO 2) and hydrogen sulphide (H 2S) were not included in the scope of the air quality assessment as the gas to fuel the turbines will be sweet natural fuel gas. 2.1 OXIDES OF NITROGEN Oxides of nitrogen (NO X) are produced in most combustion processes and are almost entirely made up of nitric oxide (NO) and nitrogen dioxide (NO 2). Nitrogen dioxide is a respiratory irritant, while NO is relatively inert. As such, ambient air quality objectives exist for NO 2 and not for NO or NO X. Nitrogen dioxide is an orange to reddish gas that is corrosive and irritating. Most NO 2 in the atmosphere is formed by the oxidation of NO, which is emitted by combustion processes, particularly those at high temperature and pressure, such as internal combustion engines. External combustion processes such as fired equipment (e.g., heaters, boilers) are also sources of NO X. The levels of NO and NO 2, and the ratio of the two gases, together with the presence of hydrocarbons and sunlight are the most important factors in the formation of ground-level ozone and other oxidants. Further oxidation, and subsequent combination with water in the atmosphere forms nitric acid, a component of acid rain. 2.2 RESPIRABLE PARTICULATE MATTER Particulate matter is classified by particle size. Particle size determines the velocity with which gravitational settling occurs and the ease with which the particles penetrate the human respiratory tract. Generally, large particles settle out very close to the source while very fine particles extend further from the source and penetrate deep into the respiratory tract. Total suspended particulates (TSP) encompass all size ranges from about 100 μm to the sub-micrometre range. Inhalable particulate matter (PM 10) consists of small particles with diameters less than 10 μm. Respirable particulate matter (PM 2.5) consists of very small particles with diameters less than 2.5 μm. The emphasis of regional air quality related to particulate matter has shifted in recent years from an emphasis on TSP to the smaller particles (particularly PM 2.5) as a result of concerns related to potential effects on human health. As a result, this assessment of particulate emissions is limited to PM CARBON MONOXIDE Carbon monoxide is a colourless, odourless gas. A product of combustion, its sources include fossil fuel combustion (e.g., motor vehicles), industrial processes and natural sources (e.g., forest fires). A typical CO concentration in the atmosphere is 120 μg/m

12 PDF Page 12 of 117 AIR QUALITY TECHNICAL DATA REPORT Substances of Interest 2.4 AMBIENT AIR QUALITY OBJECTIVES AND STANDARDS Air quality is assessed by comparing predicted ground-level concentrations to applicable objectives and standards developed by regulatory agencies. The BC and Canadian (National) Ambient Air Quality Objectives (AAQO) are shown in Table 2-1. The BC AAQO are denoted as Levels A, B and C (BC HLS 2009). The National Ambient Air Quality Objectives (NAAQO) are denoted as Desirable and Acceptable (Health Canada 2006). The BC and Canadian AAQO for some substances are very similar. The BC AAQO are defined as follows: Level A is set as the objective for new and proposed discharges and, within the limits of best practicable technology, to existing discharges by planned staged improvements for these operations. Level B is set as the intermediate objective for all existing discharges to meet within a period of time specified by the Director (BC MOE), and as an immediate objective for existing discharges which may be increasing in quantity or altered in quality as a result of process expansion or modification. Level C is set as the immediate objective for all existing chemical and petroleum industries to reach within a minimum technically feasible period of time. The NAAQO are defined as follows: The Maximum Desirable Level is the long-term goal for Air Quality and provides a basis for antidegradation policy for unpolluted parts of the country, and for the continuing development of control technology. The Maximum Acceptable Level is intended to provide adequate protection against effects on soil, water, vegetation, materials, animals, visibility, personal comfort and well-being. In 1995, the Province of BC established an Interim Level B 24-hour AAQO for PM 10 of 50 μg/m 3 (BC HLS 2009). In 2009, BC adopted AAQO for respirable particulate matter (PM 2.5) which are 25 µg/m 3 for a 24- hour averaging period (as a 98 th percentile value over one year) and 8 µg/m 3 for the annual averaging period (BC HLS 2009). In May of 2013, the Government of Canada published Canadian Ambient Air Quality Standards (CAAQS) for PM 2.5, that replaces the Canada-wide Standards for Particulate Matter (PM). These standards are to be achieved by 2015 and 2020, with the 2020 standards to be reviewed again in The CAAQS metric for PM 2.5 is 28 µg/m 3, averaged over 24-hours, and 10 µg/m 3, averaged over a year. The 24-hour metric is calculated based on a three year average of the annual 98 th percentile of the daily 24-hour average concentrations. The annual value is calculated based on a three year average of the annual average concentrations (Government of Canada 2013). It should be noted that at a location where predicted concentrations exceed an objective or standard, there needs be a receptor (e.g., resident population, sensitive ecosystem) capable of being affected by that substance for a potential effect to occur. 2.2

13 PDF Page 13 of 117 AIR QUALITY TECHNICAL DATA REPORT Substances of Interest Table 2-1 Provincial and National Ambient Air Quality Objectives and Standards Substance (Units) Averaging Period Provincial (BC) AAQO a Level Aa Level Ba Level Ca CAAQS National (Canada) Maximum Desirable NAAQOc Maximum Acceptable NO2 (µg/m 3 ) 1 hour hour 200 Annual PM2.5 (µg/m 3 ) 24 hour 25 a 28 b Annual 8 a 10 b CO (µg/m 3 ) 1 hour 14,300 28,000 35,000 15,000 35,000 NOTES: 8 hour 5,500 11,000 14,300 6,000 15,000 a BC Ministry of Healthy Living and Sport, Air Quality Objectives and Standards The PM hour average is based on 98 th percentile value for one year. b Canadian Ambient Air Quality Standards (CAAQS) for PM2.5. These objectives are referenced to the 98 th percentile 24-h concentration, averaged over three consecutive years, for the 24-hour time period, and for the annual time period it is referenced to the annual average concentrations averaged over three years (Government of Canada 2013). c National Ambient Air Quality Objectives, or NAAQO (Health Canada 2006). No applicable Objective or Standard in this Jurisdiction 2.3

14 PDF Page 14 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting 3.0 Regional Setting 3.1 STUDY AREA The proposed Aitken Creek compressor station is located approximately 100 km northwest of Fort St. John, BC at 56 46' 23.97"N and ' 08.69" W (UTM Zone 10: m N; m E). The proposed Saturn 1 compressor station is located approximately 110 km south of the proposed Aitken Creek compressor station and 30 km southwest of Fort St. John, BC at 55º 59' "N and 121º 06' 39.49"W (UTM Zone 10: m N; m E). Study area boundaries were established to focus the scope of the assessment. For this assessment, two study area boundaries were created, each extending 25 km by 25 km centered on each proposed compressor site. The study area is sized to capture all values of interest; in this case all predicted concentrations greater than 10% of the applicable ambient air quality objective. 3.2 TOPOGRAPHY Topography within each 25 km by 25 km air quality study area is shown in Figures A-1 and A-2 (Appendix A). The proposed Aitken Creek compressor site is located at a base elevation of approximately 781 metres above sea level (m asl). The proposed Saturn 1 compressor site is at a base elevation of approximately 692 m asl. 3.3 CLIMATE Climate data can be important and influence the design and operational phases of the Project. As an example, extreme ambient air temperatures are important factors to consider for the selection of construction materials and equipment, and extreme precipitation is an important factor to consider for the design of drainage systems. Climate elements also influence the transport and dispersion of air emissions from the proposed units, and must be considered as part of the environmental effects assessment. Specifically, wind speed, wind direction, and atmospheric turbulence exert major influences on the dispersion of air emissions. The following climate baseline considers measurable parameters at the nearest representative regional climate stations near the Project. The measurable parameters of the regional climatic environment that have been characterized are temperature, precipitation, relative humidity and winds. Historical climate data are available from the Canadian Climate Normal Stations (CCNS) for the 30-year period of 1971 to 2000 (Environment Canada 2013a). Table 3-1 summarizes the monitoring stations, which were used in the regional climate summary discussed throughout this section, and includes the station locations in geographic coordinates and site elevations. The Wonowon CCNS collects data on air temperature and precipitation. At 22 km to the southeast of the proposed Aitken compressor site, Wonowon is the closest CCNS to this proposed site. 3.1

15 PDF Page 15 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting The Fort St. John CCNS station is located approximately 100 km southeast of the proposed Aitken Creek compressor site and 35 km northeast from the proposed Saturn 1 compressor site, and is the closest CCNS to the proposed Saturn 1 compressor station site. Average relative humidity data is not collected at the Wonowon site however and was therefore acquired from the Fort St. John Airport CCNS station. To supplement these surface data, wind speed and direction data were extracted from the 4 km grid resolution one year Weather Research and Forecasting (WRF) model data from January 1, 2010 to December 31, 2010, surrounding each proposed compressor station sites. These data, extracted at the location of the proposed Aitken Creek compressor site, are described below. Table 3-1 Geographic Coordinates of Stations Used in the Climate Analysis Station Type Station Name Latitude Longitude CCNS Wonowon (Climate ID ) CCNS WRF WRF Fort St. John (Climate ID ) Aitken Creek Compressor Station Saturn 1 Compressor Station NOTE: CCNS = Canadian Climate Normal Station (Environment Canada 2013a) Elevation (m asl) Location (UTM NAD83) mn me Zone 56 44' N 'W ' N 'W ' N 'W ' N 'W Temperature A summary of the historical seasonal and mean air temperatures at the Wonowon and Fort St. John CCNS is provided in Table 3-2. Based on the available data, the seasonal mean daily temperatures at the Wonowon CCNS range from C in winter to 13.2 C in summer. The annual mean daily temperature is 1.0 C. At the Fort St. John CCNS seasonal mean daily temperatures range from C in winter to 14.7 C in summer. A more detailed breakdown of the monthly mean temperatures at each CCNS is shown in Figures A-3 and A-5 (Appendix A). Also shown are extreme maximum and minimum temperatures. The historical extreme temperatures at the Wonowon station range from C to 32.0 C and at the Fort St. John station from C to 33.6 C. 3.2

16 PDF Page 16 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Table 3-2 Seasonal and Mean Daily Temperatures Wonowon and Fort St. John CCNS Station Name Mean Daily Temperature ( C) Winter a Spring a Summer a Autumn a Annual Wonowon CCNS Fort St. John CCNS NOTE: a Winter Months: December, January, February; Spring Months: March, April, May; Summer Months: June, July, August; Autumn Months: September, October, November SOURCE: Environment Canada 2013a Precipitation Monthly mean and maximum daily rainfall, snowfall, and total precipitation as observed at the Wonowon and Fort St. John CCNS are presented in Tables 3-3 and 3-4. Figures A-4 and A-6 (Appendix A) are graphical representations of historical mean daily rainfall, snowfall, and total precipitation by month. At the Wonowon CCNS the June to August period is typically the wettest during the year. The historical maximum daily rainfall (61.5 mm) was recorded in the month of July. The months with the most snowfall are typically October to March. The maximum historical daily snowfall (22.8 cm) was recorded during the month of May. The months with maximum snow depth are typically during late winter and early spring, with the maximum historical daily snow depth (93 cm) recorded during the month of March. Annual precipitation is mm, with the maximum (93.6 mm) occurring during the month of July. At the Fort St. John CCNS the June to August period (summer) is typically the wettest season during the year. The historical maximum daily rainfall (80.3 mm) was recorded in the month of June. The months with the most snowfall are typically November to March. The maximum historical daily snowfall (47.8 cm) was recorded during the month of May. The months with maximum snow depth are typically during late winter and early spring, with the maximum historical daily snow depth (112 cm) recorded during the month of March. Annual precipitation is mm, with the maximum (83.2 mm) occurring during the month of July. 3.3

17 PDF Page 17 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Table 3-3 Rainfall, Snowfall, and Total Precipitation at the Wonowon CCNS Parameter Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Rainfall (mm) Mean Monthly Max Daily Snowfall (cm) Mean Monthly Max Daily Total Precipitation (mm) Mean Monthly Max Daily SOURCE: Environment Canada 2013a Table 3-4 Rainfall, Snowfall, and Total Precipitation at the Fort St. John CCNS Parameter Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Rainfall (mm) Mean Monthly Max Daily Snowfall (cm) Mean Monthly Max Daily Total Precipitation (mm) Mean Monthly Max Daily SOURCE: Environment Canada 2013a 3.4

18 PDF Page 18 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Humidity Relative humidity is the ratio of the amount of water vapour actually contained in the air compared to the maximum amount of water vapour required for saturation at air temperature. It is therefore the ratio (usually expressed as percent) of the air s water vapour content to its capacity. Table 3-5 shows the associated mean relative humidity at the Fort St. John Airport CCNS for each month at 15:00 local standard time (LST). Relative humidity values at 15:00 LST range from 40.6% to 71.8%. Relative humidity is temperature dependent. It often reaches its maximum in the predawn when air temperatures are typically at a minimum, and reaches its minimum when air temperatures are at a maximum in the early to mid-afternoon. Table 3-5 Historical Monthly Mean Relative Humidity at the Fort St. John Airport CCNS Average Relative Humidity (%) Month 15:00 LST January 69.1 February 63.8 March 55.0 April 42.6 May 40.6 June 47.3 July 51.3 August 52.7 September 53.6 October 56.9 November 71.8 December 71.6 SOURCE: Environment Canada 2013a Winds Data obtained from the Weather Research and Forecasting (WRF) model database for a 1-year period (January 1, 2010 to December 31, 2010) were analyzed to characterize wind patterns. An extraction utility provided by the United States Environmental Protection Agency (U.S. EPA) Mesoscale Model Interface (MMIF) program was used to extract surface and upper air files from the 4 km grid resolution WRF model output so it could be used in AERMET. 3.5

19 PDF Page 19 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Table 3-6 shows a summary of wind statistics at the proposed Aitken Creek and Saturn 1 compressor station location, including the maximum and average recorded wind speeds. Also presented is the frequency of recorded calms (defined as winds with speeds of less than 0.5 m/s). The mean and maximum wind speeds for the one year-period are also shown at the proposed site. Wind roses are a graphic means of presenting wind speed and direction frequency data. The length of the radial barbs gives the total percent frequency of winds from the indicated direction, while coloured portions of the barbs indicate the frequency of associated wind speed categories. Figures B-3 and B-4 (Appendix B) presents the frequency distributions of hourly average wind speed and the wind roses depicting annual wind speed and direction frequency distributions based on data extracted from WRF data between the period of January 1, 2010 and December 31, 2010 for each proposed compressor station location. The winds at the proposed Aitken Creek compressor station site are predominantly from the west southwest, west and west northwest directions. Wind speeds average 3.5 m/s (12.6 km/h). The maximum wind speed is 13.4 m/s (48.2 km/h). For 63.8% of the time, wind speeds were less than 4.0 m/s. Calm winds (less than 0.5 m/s) occur about 1.6% of the time. The winds at the proposed Saturn 1 compressor station site are predominantly from the west, west southwest and southwest directions. Wind speeds average 3.65 m/s (13.1 km/h). The maximum hourly wind speed is 15.9 m/s (57.2 km/h). For 60.5% of the time, wind speeds were less than 4.0 m/s. Calm winds (less than 0.5 m/s) occur about 1.4% of the time. Table 3-6 Summary Statistics for WRF-Derived Wind Data Parameter WRF Data for the Proposed Aitken Creek Compressor Station Location WRF Data for the Proposed Saturn 1 Compressor Station Location Station Location UTM NAD83 me UTM NAD83 mn Elevation (m asl) Start Date 1-Jan Jan-2010 End Date 31-Dec Dec-2010 Total Hours No. (% available) 8760 (100%) 8760 (100%) Calm Hrs No. (%) 143 (1.6%) 125 (1.4%) (Wind Speeds < 0.5 m/s) Maximum Wind Speed m/s (km/h) 13.4 (48.2) 15.9 (57.2) Average Wind Speed m/s (km/h) 3.51 (12.6) 3.65 (13.1) 3.6

20 PDF Page 20 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting 3.4 BASELINE AIR QUALITY Characterizing future air quality involves knowledge of both existing ambient air quality and project emissions, and how they disperse in the environment. The ambient air quality baseline summary considers measurable substances of interest at the nearest most representative continuous monitoring stations near the Project. An analysis was completed of ambient air quality monitoring data collected at nearby stations. No one station measures all substances of interest, and therefore a suite of data from a variety of stations must be examined. Data were obtained from the Alberta Clean Air Strategic Alliance (CASA) website. This assessment for baseline ambient air quality focuses on substances of interest relative to project emissions, including: oxides of nitrogen (NO X) nitrogen dioxide (NO 2) respirable particulate matter (PM 2.5) carbon monoxide (CO) A summary of the available station locations and substances monitored are provided in Table 3-7. Available data periods for each station are given in Table 3-8 by substance. The Henry Pirker station is closest, located 270 km southeast of the proposed Aitken Creek site and 170 km southeast of the proposed Saturn 1 site, that continuously measures CO concentrations and it is considered representative of the area due to its rural location. The Beaverlodge continuous monitoring station is located 240 km southeast of the proposed Aitken Creek site and 140 km southeast of the proposed Saturn 1 site. It was used to assess baseline ambient concentrations for NO X, NO 2 and PM 2.5. A summary of the statistical data analysis performed on the continuous ambient air quality monitoring data is provided in Table 3-9. The results for each substance are discussed in the following sections. 3.7

21 PDF Page 21 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Table 3-7 Continuous Ambient Air Quality Monitoring Stations Used in the Baseline Air Quality Analysis Station Name Latitude Longitude Elevation (m asl) Location (UTM NAD83) Substances Monitored me mn Zone NOX NO2 PM2.5 CO Beaverlodge 55 12'N 'W x x x Henry Pirker 55 06'N 'W x SOURCE: CASA 2009 Table 3-8 Data Periods for Continuous Ambient Air Quality Monitoring Stations Used in the Baseline Air Quality Analysis Monitoring Data Period Station Name NOX NO2 PM2.5 CO SO2 Beaverlodge January 1, 2008 January 1, 2008 January 1, 2008 N/A N/A June 30, 2013 June 30, 2013 June 30, 2013 Henry Pirker N/A N/A N/A January 1, 2008 June 30, 2013 NOTE: N/A = Not applicable N/A 3.8

22 PDF Page 22 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Table 3-9 Summary of Continuous Ambient Air Quality Monitoring Data at Stations Used in the Baseline Air Quality Analysis Substance NOX (µg/m 3 ) Parameter AAQO (Table 2-1) Beaverlodge Henry Pirker One-hour Maximum N/A 188 N/A One-hour 99 th Percentile N/A 67 N/A One-hour 98 th Percentile N/A 51 N/A Mean One-hour Average N/A 9.1 N/A 24-hour Maximum N/A 89 N/A 24-hour Average N/A 9.2 N/A Annual Average N/A 9.9 N/A NO2 (µg/m 3 ) PM2.5 (µg/m 3 ) One-hour Maximum N/A One-hour 99 th Percentile N/A 44.2 N/A One-hour 98 th Percentile N/A 37.2 N/A Mean One-hour Average N/A 7.5 N/A 24-hour Maximum N/A 24-hour Average N/A 7.5 N/A Annual Average N/A One-hour Maximum N/A 322 N/A One-hour 99 th Percentile N/A 29 N/A One-hour 98 th Percentile a N/A Mean One-hour Average N/A 6.54 N/A 24-hour Maximum N/A 84.8 N/A 24-hour Average N/A 6.52 N/A Annual Average N/A CO (µg/m 3 ) One-hour Maximum 14,300 N/A 3161 NOTES: N/A = not applicable. One-hour 99 th Percentile N/A N/A 882 One-hour 98 th Percentile N/A N/A 699 Mean One-hour Average N/A N/A hour Maximum 5,500 N/A 1,407 8-hour Average N/A N/A 249 Values in bold identify ambient concentrations applied in this assessment a BC Ministry of Healthy Living and Sport, Air Quality Objectives and Standards The PM hour average is based on 98 th percentile value for one year. 3.9

23 PDF Page 23 of 117 AIR QUALITY TECHNICAL DATA REPORT Regional Setting Oxides of Nitrogen and Nitrogen Dioxide As shown in Table 3-9, the maximum one-hour, 24-hour, and annual average NO X concentrations for Beaverlodge were 188, 89, and 10 µg/m 3, respectively. There are no regulatory criteria for ground-level NO X concentrations. Similarly, in Table 3-9, the mean one-hour average NO 2 concentration for Beaverlodge was 8 µg/m 3 and maximum one-hour, 24-hour concentrations were 94 and 64 µg/m 3, respectively. These values are much less than the National AAQO for one-hour, 24-hour and annual average NO 2 concentrations (400 µg/m 3, 200 µg/m 3, and 100 µg/m 3, respectively. The observed NO 2 concentrations at this site indicate little potential for adverse effects Respirable Particulate Matter Inhalable particulate matter (PM 2.5) is monitored continuously at the Beaverlodge air quality monitoring station. As shown in Table 3-9, the mean one-hour average PM 2.5 concentration at the Beaverlodge monitoring station was 6.54 µg/m 3 and the maximum one-hour concentration was 322 µg/m 3. The 24-hour average PM 2.5 concentration recorded at Beaverlodge monitoring station, based on annual 98 th percentile averaged over 3 years, was 21.6 µg/m 3. This value is less than the 30 µg/m 3 CWS and the 25 µg/m 3 AAQO for 24-hour average PM 2.5 concentrations. The average 24-hour PM 2.5 concentration (6.52 µg/m 3 ) is also lower Carbon Monoxide As shown in Table 3-9, the mean one-hour average CO concentration for Henry Pirker was 249 µg/m 3. The maximum, 99 th, and 98 th percentile one-hour average concentrations were 882 and 699 µg/m 3, respectively. These values are much less than the BC HLS (2009) Level A AAQO for one-hour average CO concentrations (14,300 µg/m 3 ). At the Henry Pirker monitoring station, the maximum 8-hour average CO concentration was 1,407 µg/m 3. This value is lower than the 5,500 µg/m 3 BC HLS (2009) Level A AAQO for 8-hour average CO concentration. 3.5 SUMMARY Generally, the baseline ambient air quality in the region is good, with rare occurrences of poor air quality. Baseline air quality in the region is influenced primarily by regional industrial air emission sources and traffic near the site. All monitored concentrations of NO 2, PM 2.5 and CO have been below the applicable regulatory criteria for ambient air quality. In addition to anthropogenic sources, forest fires can cause elevation of PM 2.5 levels during such occurrences for considerable distances, but are not known to have contributed to any readings described here. 3.10

24 PDF Page 24 of 117 AIR QUALITY TECHNICAL DATA REPORT Modelling Methodology 4.0 Modelling Methodology 4.1 AERMOD DISPERSION MODEL For this assessment, the AERMOD plume dispersion model was applied to evaluate the effect of project emissions from continuous emission sources. AERMOD is a steady-state plume dispersion model developed by the United States Environmental Protection Agency (US EPA 2004a, 2004b). The model is designed to estimate near-field (less than 50 km) ground-level concentrations from most types of industrial emission sources. The AERMOD modelling system consists of three programs: the plume dispersion model (AERMOD), a meteorological pre-processor (AERMET), and a terrain pre-processor (AERMAP). Version (December 2012) was used in this assessment. The AERMOD dispersion model is recommended for refined air quality assessments in the BC Model Guidelines (BC MOE 2008). 4.2 DISPERSION METEOROLOGY Meteorology influences the manner in which air emissions from industrial and natural sources disperse into the atmosphere, and affect air quality. Atmospheric dispersion of emissions is governed by wind speed and the turbulence that exists in the mixed layer of air in contact with the ground. Turbulence levels depend on thermal effects (e.g., vertical temperature stratification) and mechanical effects caused by topography, surface roughness and wind speed. The height of the mixing layer determines the vertical extent to which emissions are able to diffuse. For this assessment, WRF meso-meteorological data for the year 2010 were used in the dispersion modelling. Historically, the MM5 meteorological model has been the standard used. However, MM5 has been officially phased out by the National Center for Atmospheric Research (NCAR). NCAR announced on October 31, 2008 that technical support for the MM5 model has been discontinued and strongly encouraged users to move to the new NCAR supported WRF model. The WRF model provides better algorithms, handling of topography, and programming compared to MM5. It also includes new features and options developed by the Mesoscale & Microscale Meteorology Division at NCAR. A recently published U.S. Western Regional Air Partnership (WRAP) report has demonstrated that WRF outperforms MM5 in overall model accuracy (US WRAP 2012). The AERMOD meteorological preprocessor AERMET was used to process the meteorological dataset used in dispersion modelling (US EPA 2004b). AERMET is used to estimate two stability parameters, friction velocity and Monin-Obukhov length, to characterize the amount of turbulence in the atmosphere. The friction velocity is a measure of mechanical effects alone, such as wind shear at ground-level. The Monin- Obukhov length indicates the relative strengths of mechanical and buoyancy effects on atmospheric turbulence. AERMOD can account for turbulence from both wind shear and from buoyancy effects due to solar heating during the day and radiation cooling at night. To properly account for these effects, AERMET requires three land use parameters: albedo, Bowen ratio, and surface roughness. Albedo is the fraction of total incident solar radiation reflected by a particular surface without absorption. Bowen ratio is defined as the ratio of the sensible heat flux to the latent heat flux and can be an indicator of surface moisture conditions. Surface roughness is a length scale that characterizes the roughness of the earth s 4.1

25 PDF Page 25 of 117 AIR QUALITY TECHNICAL DATA REPORT Modelling Methodology surface. Bowen ratio can vary significantly over the course of the day; however, it usually remains fairly constant during mid-day. For this assessment, site-specific values for albedo, Bowen ratio, and surface roughness were selected based on land use within 3 km of the Project recommended by the BC Model Guidelines (BC MOE 2008). These values are shown in Table B-1 (Appendix B). 4.3 RECEPTOR GRIDS AND TERRAIN Predictions of ground-level concentrations were made for locations on and outside the fenceline for the Aitken Creek and Saturn 1 compressor stations, according to the BC Model Guidelines (BC MOE 2008), using a series of nested Cartesian grids with increasing receptor density and proximity to the compressor stations. The receptor grids and their corresponding spacing are shown in Figure A-7 and A-8 (Appendix A). They are as follows: 20 m receptor spacing along the plant boundary 1 50 m spacing within 500 m of source 250 m spacing within 2 km of source 500 m spacing within 5 km of source 1,000 m spacing beyond 5 km of source 1 as defined in Section 6.3 of the Guidelines (BC MOE 2008) Terrain elevations were applied to all receptors used in dispersion modelling based on the Global Digital Elevation Data (1.5 arc sec resolution). 4.4 BUILDING DOWNWASH EFFECTS Buildings or other solid structures can affect the flow of air near a source and may induce building downwash effects (e.g., eddies on the downwind side), which have the potential to reduce plume rise and affect dispersion. For dispersion modelling purposes, building downwash effects were considered for all point sources as proposed for the Aiken Creek and Saturn 1 compressor stations. The buildings and structures that were considered in dispersion modelling of both compressor stations are summarized in Tables 4-1 and 4-2 and illustrated in Figures A-9 and A-10 (Appendix A). 4.2

26 PDF Page 26 of 117 AIR QUALITY TECHNICAL DATA REPORT Modelling Methodology Table 4-1 Buildings and Structures Considered in Dispersion Modelling (Aitken Creek Compressor Station) Building ID Aitken Creek Description Length (m) Width (m) Height (m) 1 Compressor Building PPU #1 Generator Skid PPU #2 Generator Skid Mechanical Skid Electrical Skid Personnel Skid Heated Storage Building Progress Energy Compressor Station 8 Office Air Compressor Building Cold Storage Building Sales Gas Area Fuel Gas Separator Building Sales Gas Meter Building Dehydrator Building # Dehydrator Building #2 (Future) Inlet Separator Building Inlet Separator Building (Future) Compressor Building C Compressor Building C Compressor Building C Compressor Building C Produced Water Tanks SOURCE: NGTL 2013; Progress Energy Canada Ltd

27 PDF Page 27 of 117 AIR QUALITY TECHNICAL DATA REPORT Modelling Methodology Table 4-2 Buildings and Structures Considered in Dispersion Modelling (Saturn 1 Compressor Station) Building ID Saturn 1 Description Length (m) Width (m) Height (m) 1 Compressor Building PPU #1 Generator Skid PPU #2 Generator Skid Mechanical Skid Electrical Skid Personnel Skid Heated Storage Building SOURCE: NGTL NOX TO NO2 CONVERSION Ambient air quality objectives exist for NO 2 rather than total NO X. Therefore it is important to estimate the portion of AERMOD predicted NO X concentrations in the form of NO 2. The BC Model Guidelines (BC MOE 2008) recommends reporting the results as NO X (100% conversion), if the maximum NO X concentrations are less than the ambient objectives for NO X. For this study all NO 2 will be reported as NO X (100% conversion). 4.6 EXISTING INDUSTRIAL SOURCES AND BACKGROUND AIR QUALITY Existing industrial emission sources within a 5 km radius of the Aitken Creek and Saturn 1 compressor stations were considered for inclusion in dispersion modelling, as recommended in the BC Model Guidelines (BC MOE 2008). Based on a search of the National Pollutant Release Inventory (NPRI) database, it was determined that there are two existing industrial facilities located within 5 km of the proposed Aitken Creek compressor site; the ConocoPhillips Canada Resources Corp. Gundy Compressor Station and the Progress Energy Resources Corp. Gundy B-069-A/094-B-16. Both facilities are located approximately 4 km from the proposed compressor site and their emissions are relatively small. They were deemed incapable of interacting cumulatively with the Project such that an exceedance of regulatory objectives might occur. They were not included in the current modelling. Another facility, currently under construction, was identified within the 5 km radius of the proposed Aitken Creek site, Progress Energy Canada Ltd. West Gundy Compressor Station. This facility is currently being constructed approximately 25 m northeast of the Aitken site and it was included in the dispersion modelling conducted for the Aitken Creek compressor station. The location of this facility is shown on Figure A-9 (Appendix A). 4.4

28 PDF Page 28 of 117 AIR QUALITY TECHNICAL DATA REPORT Modelling Methodology There are no known existing facilities located within 5 km of the proposed Saturn 1 compressor station. A gas processing facility (Shell 3-28 Saturn Gas Processing Plant) is currently being constructed approximately 4 km southeast of the proposed Saturn 1 compressor station. As emissions data for this facility were not available at the time of this assessment they were not included in the dispersion modelling scenarios for the proposed Saturn 1 compressor station. As presented in Section 5.0 however, the predicted one-hour ground level concentrations of NO 2, based on the operation of the proposed Saturn 1 compressor station, at this distance are negligible (approximately 5 µg/m 3 ) and would therefore not cumulatively interact with the operation of the new Shell facility such that an exceedance of regulatory objectives might occur. To account for the other potential air emission sources (natural and human-caused) inside and outside of the 25 km x 25 km study area that have not been included in the dispersion modelling assessment, representative background (or reference) ambient air quality concentrations for each of the substances of interest are required. The background ambient air quality is generally established based on an analysis of regional ambient air quality monitoring data. For a summary of the background concentrations used for this assessment, see Table 3-9. (Section 3.4: Baseline Air Quality). 4.7 MODELLING SCENARIOS Three dispersion modelling scenarios were investigated for each proposed compressor station and included: 1. Baseline Case includes the emissions from existing facilities surrounding the proposed compressor station sites. For the Aitken Creek compressor site this includes the West Gundy Compressor Station. For the Saturn 1 compressor site there are no existing nearby facilities known to contribute cumulatively with the proposed compressor station. 2. Project Only Case includes the emissions from the operation of the Aitken and Saturn 1 compressor stations (compressor turbines, boilers and generators). The operation of each proposed compressor station was modelled separately as the separation distance between the two proposed facilities is roughly 100 km and therefore the 25 km x 25 km modelling domains do not overlap. 3. Application Case includes the emissions from both the Baseline Case and the Project Only Case for the Aitken Creek compressor site. 4.8 EMISSION RATES Air emissions associated with the operation of the Aitken Creek and Saturn 1 compressor stations were provided by NGTL. These operational sources include compressor turbines (one per compressor station), boilers (one per compression station) and generators (one per compressor station). Emission estimates were based upon a similar facility (RWDI 2011). Air emissions associated with existing the West Gundy Compressor Station were obtained from the operators and were included in the dispersion modelling as a baseline source. 4.5