Canada’s Air Pollutant Emissions Inventory Report 2020: chapter 3

Air pollutant emissions inventory development

The Air Pollutant Emissions Inventory (APEI) is a comprehensive and detailed inventory of air pollutant emissions in Canada, developed using two types of information:

The APEI is developed using many sources of information, procedures and emission estimation models. Emissions data reported by individual facilities to Environment and Climate Change Canada’s (ECCC’s) National Pollutant Release Inventory (NPRI) are supplemented with documented, science-based estimation tools to quantify total emissions. Together, these data sources provide a comprehensive overview of pollutant emissions across Canada. A framework has been developed that makes use of the best available data, while ensuring that there is no double-counting or omissions. This chapter presents information about the inventory development process.

3.1 Overview of inventory development

The process of developing comprehensive emission estimates for the APEI consists of  categorizing facility-reported data (section 3.2), calculating in-house estimates (section 3.3), reconciling the facility-reported data and the in-house estimates in a database where necessary (section 3.4), followed by compiling and reporting the results (Figure 3–1). Quality control is performed throughout inventory development (section 3.5), and continuous improvement often results in revisions to previously published estimates (section 3.6).

Facility-reported emissions

As a first step, seventeen pollutants reported in the APEI are extracted from the NPRI verified database, which contains facility-reported data. New facilities are identified in the extracted data and classified within the APEI according to the nature of their activities. This step results in a compiled database containing all needed facility-reported emissions for the air pollutant inventory report.

Facility-reported data from the NPRI are used in the inventory without modifications except when 1) data quality issues are detected and 2) adjustments are needed to Particulate matter (PM) fractions.

More information on facility-reported emissions is presented in section 3.2

In-house emission estimates

In-house estimates are based on documented estimation methodologies, periodically reviewed and updated through literature searches, the collection and analysis of recent emission factors and activity data, and comparisons with alternative sources of information. Updated estimates are calculated using new and/or updated activity data. Where possible, inventory estimates calculated in-house use the most rigorous (highest-tier) methods; however, owing to practical limitations, the exhaustive development of all emissions categories is not possible. In these cases, estimates are generally calculated using activity data and emission factors following relatively basic (lower-tier) methodologies. Calculations are performed in spreadsheets (Excel), SQL queries (MS Access and SQL server), or using computational scripts (R and Python) and may include spatial data quantified using geographic information systems software (GIS-ArcGIS and QGIS).

More information on in-house estimates can be found in section 3.3.

Reconciliation

The next step in the compilation process is the elimination of any double-counting of emissions between the in-house estimates and the facility-reported data by a process of reconciliation. Table 3–1 illustrates the origin of the emissions for each sector and subsector: facility-reported data, in-house calculated data or a combination of both, for the latest available year. Note the origin can change depending on the year. Reconciliation of in-house estimates with facility-reported data is required for sectors or subsectors where both in-house and facility-reported estimates exist. For 2018, reconciliation was performed for about 28 sectors.

More information on reconciliation is available in section 3.4.

Compilation and reporting

The final steps in the development process involves compiling all reconciled data within a final database and generating the results. The final database houses all APEI data and is the source of data for all APEI-related products, including:

Figure 3–1: Overview of the annual air pollutant emissions inventory compilation process

Figure 3–1 section-3.2 section-3.3 section-3.4 Database Open Data Table Online Search Tool UNECE Submission

Long description for Figure 3–1

Figure 3-1 is a flow chart displaying an overview of Canada’s annual Air Pollutant Emissions Inventory compilation process. In this figure, there are two big boxes side by side at the top; the big box on the left describes Facility-Reported Emissions process and the big box on the right describes In-House Emission process. More details on Facility-Reported Emissions can be found in Section 3.2 and more details on In-House Emissions Estimates can be found in Section 3.3.

Within the big box on the top left, there are several small boxes with arrows indicating the steps and order of the steps to describe the Facility-Reported Emissions process. The first box is the NPRI database (Facility-Reported Data). From that box, an arrow points to the next step: the Extraction of the Seventeen Pollutants Needed for Report box. Another arrow points from there to the box New Facilities Categorized into Appropriate Sectors and Subsectors. An arrow points from there to a circle representing the Facility Data for the Air Pollutant Inventory Database. From this database, a two-way arrow is used to point to the Particulate Matter Corrections box.

In the big box on the top right-hand side of this figure, in the first box is Activity Data and Emissions Factors. From there, one arrow splits off to the left, Tier 1 is written on the arrow, and leads to Calculation of In-House Estimates. Another arrow splits off to the right, Tier 2 and Tier 3 is written on the arrow, and leads to Emissions Models which then has another arrow leading to Calculation of In-House Estimates.

Both, the big top left box and the big top right box then merge into the Reconciliation step. More details on the reconciliation steps are provided in Section 3.4. From there, an arrow points from Reconciliation to a circle representing the Air Pollutant Inventory Database. From there, five arrows split off to five reporting steps: from left to right they read Emissions Tables and Figures for Report, Open Data Tables, Online Search Tool, UNECE Submission and the last one: Projections, Air Quality Modeling, CESI Indicators and Canada-U.S. Air Quality Agreement.

Table 3–1: 2018 Air Pollutant Emissions Inventory

Note :
x = yes

Ore and Mineral Industries
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Aluminium Industry Alumina (Bauxite Refining) x - -
Aluminium Industry Primary Aluminium Smelting and Refining x - -
Aluminium Industry Secondary Aluminium Production (Includes Recycling) x - -
Asphalt paving Industry - x x 2018
Cement and Concrete Industry Cement Manufacturing x - -
Cement and Concrete Industry Concrete Batching and Products x x 2018
Cement and Concrete Industry Gypsum Product Manufacturing x - -
Cement and Concrete Industry Lime Manufacturing x - -
Foundries Die Casting x - -
Foundries Ferrous Foundries x x 2011
Foundries Non-ferrous Foundries x - -
Iron and Steel Industry Primary (Blast Furnace and DRI) x - -
Iron and Steel Industry Secondary (Electric Arc Furnaces) x x 2018 (Hg in Products)
Iron and Steel Industry Steel Recycling x x 2018 (Hg in Products)
Iron Ore Industry Iron Ore Mining x - -
Iron Ore Industry Pelletizing x - -
Mineral Products Industry Clay Products x - -
Mineral Products Industry Brick Products x - -
Mineral Products Industry Other (Mineral Products Industry) x - -
Mining and Rock Quarrying Coal Mining Industry x - -
Mining and Rock Quarrying Metal Mining x - -
Mining and Rock Quarrying Potash x - -
Mining and Rock Quarrying Rock, Sand and Gravel x x 2018
Mining and Rock Quarrying Silica Production - x 2018
Mining and Rock Quarrying Limestone x - -
Mining and Rock Quarrying Other (Mining and Rock Quarrying) x - -
Non-Ferrous Refining and Smelting Industry Primary Ni, Cu, Zn, Pb x - -
Non-Ferrous Refining and Smelting Industry Secondary Pb, Cu x - -
Oil and Gas Industry
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Downstream Oil and Gas Industry Petroleum Refining x - -
Downstream Oil and Gas Industry Refined Petroleum Products Bulk Storage and Distribution x x 2016
Downstream Oil and Gas Industry Refined Petroleum Product Pipelines x - -
Downstream Oil and Gas Industry Natural Gas Distribution x x 2017
Downstream Oil and Gas Industry Other (Downstream Oil and Gas Industry) x - -
Upstream Oil and Gas Industry Accidents and Equipment Failures - x 2018
Upstream Oil and Gas Industry Disposal and Waste Treatment - x 2018
Upstream Oil and Gas Industry Heavy Crude Oil Cold Production - x 2018
Upstream Oil and Gas Industry Light/Medium Crude Oil Productionc x x 2018
Upstream Oil and Gas Industry Natural Gas Production and Processingd x x 2018
Upstream Oil and Gas Industry Natural Gas Transmission and Storage x x 2017
Upstream Oil and Gas Industry Oil Sands In-Situ Extraction x x 2018
Upstream Oil and Gas Industry Oil Sands Mining, Extraction and Upgrading x - -
Upstream Oil and Gas Industry Petroleum Liquids Storage x - -
Upstream Oil and Gas Industry Petroleum Liquids Transportation - x 2018
Upstream Oil and Gas Industry Well Drilling/Servicing/Testing - x 2018
Electric Power Generation (Utilities)
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Coal - x - -
Diesel - x - -
Natural gas - x - -
Waste materials - x - -
Other (Electric Power Generation) - x - -
Manufacturing
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Abrasives Manufacturing - x - -
Bakeries - x x 2018
Biofuel Production - x - -
Chemicals Industry Chemical Manufacturing x - -
Chemicals Industry Cleaning Compound Manufacturing x - -
Chemicals Industry Fertilizer Production x - -
Chemicals Industry Paint and Varnish Manufacturing x - -
Chemicals Industry Petrochemical Industry x - -
Chemicals Industry Plastics and Synthetic Resins Fabrication x - -
Chemicals Industry Other (Chemical Industry) x - -
Electronics - x x 2018 (Hg in Products)
Food Preparation - x - -
Glass Manufacturing - x - -
Grain Industry Grain Processing x x 2018
Grain Industry Warehousing and Storage x - 2018
Metal Fabrication - x - -
Plastics Manufacturing - x - -
Pulp and Paper Industry Pulp and Paper Product Manufacturing x -
-
Pulp and Paper Industry Converted Paper Product Manufacturing x - -
Textiles - x - -
Vehicle Manufacture (Engines, Parts, Assembly, Painting) - x - -
Wood Productse Panel Board Mills x x 2018
Wood Products Sawmills x x 2018
Wood Products Other (Wood Products) x - -
Other (Manufacturing) - x - -
Transportation and Mobile Equipment
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Air Transportation - - x 2018
Heavy-duty Diesel Vehicles - - x 2018
Heavy-duty Gasoline Vehicles - - x 2018
Heavy-duty LPG/NG Vehicles - - x 2018
Light-duty Diesel Trucks - - x 2018
Light-duty Diesel Vehicles - - x 2018
Light-duty Gasoline Trucks - - x 2018
Light-duty Gasoline Vehicles - - x 2018
Light-duty LPG/NG Trucks - - x 2018
Light-duty LPG/NG Vehicles - - x 2018
Marine Transportation - - x 2015
Motorcycles - - x 2018
Off-road Diesel Vehicles and Equipment - - x 2018
Off-road Gasoline/LPG/NG Vehicles and Equipment - - x 2018
Rail Transportation - - x 2018
Tire Wear-and Brake Lining - - x 2018
Agriculture
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Animal Production - - x 2018
Crop Production Harvesting - x 2018
Crop Production Inorganic Fertilizer Application - x 2018
Crop Production Sewage Sludge Application - x 2018
Crop Production Tillage Practices - x 2018
Crop Production Wind Erosion - x 2018
Fuel Use - x x 2014
Commercial / Residential / Institutional
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Cigarette Smokingf - - x 2018
Commercial and Institutional Fuel Combustion - x x 2017
Commercial Cooking - - x 2018
Construction Fuel Combustion - - x 2017
Home Firewood Burning - - x 2017
Humanf - - x 2018
Marine Cargo Handling - x - -
Residential Fuel Combustion - - x 2014
Service Stations - - x 2018
Other (Miscellaneous)g - - x 2018
Incineration and Waste
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Crematoriums - x x 2018
Waste Incineration Municipal Incineration x x 2018
Waste Incineration Residential Waste Burningh - x 2016
Waste Incineration Sewage Sludge Incineration - x 2018
Waste Incineration Other (Waste Incineration) x - -
Waste Treatment and Disposal Landfills x x 2018
Waste Treatment and Disposal Municipal Wastewater Treatment and Discharge x - -
Waste Treatment and Disposal Specialized Waste Treatment and Remediation x - -
Waste Treatment and Disposal Biological Treatment of Waste x - -
Waste Treatment and Disposal Waste Sorting and Transfer x - -
Paints and Solvents
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Dry Cleaning - x x 2018
General Solvent Use - - x 2018
Printing - x x 2018
Surface Coatings - x x 2018
Dust
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Coal Transportation - - x 2018
Construction Operations - - x 2012
Mine Tailings - - x 2018
Paved Roads - - x 2018
Unpaved Roads - x x 2018
Fires
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Prescribed Burning - - x 2018
Structural Fires - - x 2017
Mercury
Sector Subsector Facility-reported dataa In-house estimatesb Activity data used for in-house estimates
Mercury in products i - - x 2018

Notes:

a Based on the most recent facility-reported data from NPRI.

b Estimated by ECCC.

c Facility-reported data consists of facilities located in Atlantic Canada. For other provinces, it consists of in-house estimates.

d Facility-reported data consists of facilities located in Atlantic Canada and SO2 emissions from Alberta's natural gas processing facilities.

e In-house estimates for Wood Products were estimated by the Forestry Products group of the Environmental Stewardship Branch at ECCC. All other in-house estimates were estimated by PIRD.

f Ammonia emissions from Infant Diapered Waste, which were previously reported under Other (Miscellaneous), are now reported under the Human sector. Infant Diapered Waste as well as Cigarette Smoking (which is included within the Human sector) are being considered for removal from future inventories. If you have any questions, please contact us at ec.iepa-apei.ec@canada.ca or 1-877-877-8375.

g Emissions reported under Other (Miscellaneous) are from breakage, transport and recycling of mercury-containing products using the Hg in Products Methodology. Products include: automotive mercury switches, batteries, dental amalgams, fluorescent lamps, fungicides, measurement and control devices, non-fluorescent lamps, switches and relays, thermometers, thermostats and tire balancers.

h Hg in Products estimates for Residential Waste Burning are not estimated after 2008 as a result of the updates for the Hg in Products models.

i Emissions from Hg-containing products were calculated as a separate inventory. Emissions are reported under many sectors such as Iron and Steel Industry, Municipal Incineration, Human, Other (Miscellaneous) and Landfills. All in-house estimates for Hg in product emissions continue to be estimated and reported under these sectors.

3.2 Facility-reported emissions data

Facility-reported emissions data generally refers to any stationary sources that emit pollutants through stacks or other equipment at specific locations. The major source of facility-reported data is the NPRI, Canada’s legislated, publicly accessible inventory of pollutant releases (to air, water and land), disposals and transfers for recycling. The NPRI has provided facility-reported data on the 17 pollutants included in the APEI for more than 6,000 industrial and commercial facilities since 2002 and for 10 pollutants (polycyclic aromatic hydrocarbons [PAHs], heavy metals, dioxins and furans [D/F], hexachlorobenze [HCB] and ammonia [NH3]) since 1994. Prior to 2002, facility-level emissions for the criteria air contaminants were collected and compiled by provincial, territorial and regional environmental authorities across Canada and provided to Environment and Climate Change Canada for inclusion within the APEI.

Facility-reported data from the NPRI are used in the APEI without modifications, except when 1) data quality issues are detected and not addressed during the quality control exercise, or 2) adjustments to PM emissions are necessary to respect their size fraction. The NPRI reporting requirements and thresholds vary by pollutant and, in some cases, by industry. Details on these reporting requirements and thresholds are available on Environment and Climate Change Canada’s website in the National Pollutant Release Inventory.

A distinction has been made between reporting facilities and non-reporting facilities. Reporting facilities meet the threshold required to report to the NPRI while non-reporting facilities do not meet the threshold due to their size or emission levels and are therefore not required to report to the NPRI. Some facilities may be required to report emissions on only certain pollutants. Therefore, emissions from the non-reporting facilities or of non-reported pollutants must be estimated in-house to ensure complete coverage.

Historically (e.g. for the years 1985, 1990, 1995 and 2000), facility-reported data was primarily provided by provinces. In some cases, additional information was calculated to fill in intervening years or to update the original submissions. Trends for the intervening years were interpolated. The compilation of emissions for 2001–2005 occurred during a transition to using emissions data reported to the NPRI as the major source of industrial emissions. In general, facility-reported data from the NPRI and data provided by provinces were used for years 2002, 2004 and 2005, and interpolation was used for 2001 and 2003.

Since 2005, information on facility-reported data has originated mainly from the NPRI, with limited data obtained from provincial governments (Alberta, Manitoba, New Brunswick, Newfoundland, Ontario and Quebec) on selected sources that are not reported to the NPRI.

The NPRI groups substances into the five parts listed below. Each part has its own reporting thresholds or triggers of mandatory reporting.

Table 3–2 shows the 17 air pollutants reported in the APEI and their NPRI reporting thresholds. Details on the NPRI reporting requirements for each substance group are available online. No VOC data collected under Part 5 is used in the APEI.

Table 3–2: National Pollutant Release Inventory air pollutant reporting thresholds
Substance National Pollutant Release Inventory part # (threshold category) Mass threshold Concentration threshold
Ammonia 1A 10 tonnes MPO MPO by weight of ≥ 1%
Benzo(a)pyrene 2 50 kg total PAHs NA*
Benzo(b)fluoranthene 2 50 kg total PAHs NA
Benzo(k)fluoranthene 2 50 kg total PAHs NA
Cadmium 1B 5 kg MPO MPO by weight of ≥ 0.1%
Carbon monoxide 4 20 tonnes air release NA
Dioxins and furans 3 Activity-based NA
Hexachlorobenzene 3 Activity-based NA
Indeno(1,2,3-c,d)pyrene 2 50 kg total PAHs NA
Lead 1B 50 kg MPO MPO by weight of ≥ 0.1%
Mercury 1B 5 kg MPO NA
Nitrogen oxides 4 20 tonnes air release NA
PM10 - particulate matter ≤ 10 microns 4 0.5 tonnes air release NA
PM2.5 - particulate matter ≤ 2.5 microns 4 0.3 tonnes air release NA
Sulphur dioxide 4 20 tonnes air release NA
Total particulate matter 4 20 tonnes air release NA
Volatile organic compounds 4 10 tonnes air release NA

Notes:

MPO = Manufactured, processed or otherwise used

* NA = Not applicable

In 2018, approximately 6,000 facilities reported releases to air of one or more APEI pollutants to the NPRI.

Using the 2018 NPRI database, with data available as of November 1, 2019, facility information and air emissions data for pollutants listed in Table 3–2 were extracted for each province and territory. The quality control process described in section 3.5 was applied to the NPRI data to identify outliers or missing substance reports. Emissions data for each facility reporting to the NPRI was assigned to an APEI source, sector and subsector.

For facilities reporting to the NPRI for the first time, the North American Industry Classification System (NAICS) codes (Statistics Canada, 2017), reported by the facilities, is used to assign a preliminary APEI sector and subsector classifications. Then, additional research and verification are performed to confirm or correct the classification.

NPRI reporting facilities may not report all three of the PM size fractions. For cases where only one or two of the three PM size fractions were reported to the NPRI, a distribution procedure is applied to estimate a complete set of PM emissions for facilities. The procedure is based on sector-specific PM distribution profiles developed using PM emissions reported by facilities to the NPRI for the 2006 to 2016 data years. Ratios were calculated for each facility and averaged by sector. The resulting distributions are presented in Table 3–3.

The PM distribution procedure described in equations 3–1, 3–2 and 3–3 is applied on a case-by-case basis to fill data gaps.

Equation 3–1: PM10 distribution ratio

PM10 ratio = PM10 emissions / TPM emissions

Where

PM10 ratio = Ratio of the sector’s PM10 emissions to TPM emissions

PM10 emissions = PM10 emissions for the sector

TPM emissions = TPM emissions for the sector

Equation 3–2:  PM2.5 distribution ratio

PM2.5 ratio = PM2.5 emissions / TPM emissions

Where

PM2.5 ratio = Ratio of the sector’s PM2.5 emissions to TPM emissions

PM2.5 emissions = PM2.5 emissions for the sector

TPM emissions = TPM emissions for the sector

Equation 3–3:  PM2.5/PM10 distribution ratio

PM2.5 / PM10 ratio = PM2.5 emissions / PM10 emissions

Where

PM2.5/PM10 ratio = Ratio of the sector’s PM2.5 emissions to the PM10 emissions

PM2.5 emissions = PM2.5 emissions for the sector

PM10 emissions = PM10 emissions for the sector

The TPM, PM10 and PM2.5 emissions calculated using the distribution procedure are added to the list of facility-reported data and flagged as an ECCC estimate within the compiled APEI final database.

Table 3–3 Particulate Matter distribution ratios

Ore and Mineral Industries
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Aluminium industry Alumina (Bauxite Refining) 0.399 0.309 0.798
Aluminium industry Primary Aluminium Smelting and Refining 0.686 0.559 0.798
Aluminium industry Secondary Aluminium Production (Includes Recycling) 0.951 0.937 0.926
Asphalt Paving industry 0.385 0.177 0.513
Cement and Concrete Industry Cement Manufacturing 0.623 0.31 0.474
Cement and Concrete Industry Concrete Batching and Products 0.497 0.23 0.465
Cement and Concrete Industry Gypsum Product Manufacturing 0.715 0.508 0.643
Cement and Concrete Industry Lime Manufacturing 0.576 0.309 0.512
Foundries Die Casting 0.711 0.51 0.81
Foundries Ferrous Foundries 0.711 0.51 0.723
Foundries Non-ferrous Foundries 0.927 0.49 0.719
Iron and Steel Industry Primary (Blast Furnace and DRI) 0.598 0.403 0.65
Iron and Steel Industry Secondary (Electric Arc Furnaces) 0.616 0.474 0.802
Iron and Steel Industry Steel Recycling 0.711 0.51 0.287
Iron and Steel Industry Other (Iron and Steel Industry)
Iron Ore Industry Iron Ore Mining 0.513 0.191 0.432
Iron Ore Industry Pelletizing 0.48 0.212 0.41
Mineral Products Industry Clay Products 0.802 0.094 0.484
Mineral Products Industry Brick Products 0.757 0.23 0.323
Mineral Products Industry Other (Mineral Products Industry) 0.762 0.545 0.665
Mining and Rock Quarrying Coal Mining Industry 0.368 0.064 0.147
Mining and Rock Quarrying Metal Mining 0.532 0.283 0.509
Mining and Rock Quarrying Potash 0.599 0.316 0.503
Mining and Rock Quarrying Rock, Sand and Gravel 0.46 0.165 0.397
Mining and Rock Quarrying Silica Production
Mining and Rock Quarrying Limestone 0.460 0.165 0.397
Mining and Rock Quarrying Other (Mining and Rock Quarrying) 0.465 0.197 0.398
Non-Ferrous Refining and Smelting Industry Primary Ni, Cu, Zn, Pb 0.649 0.375 0.606
Non-Ferrous Refining and Smelting Industry Secondary Pb, Cu 0.574 0.396 0.748
Non-Ferrous Refining and Smelting Industry Other (Non-Ferrous Refining and Smelting Industry) 0.494 0.444 0.859
Oil and Gas Industry
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Downstream Oil and Gas Industry Petroleum Refining
Downstream Oil and Gas Industry Refined Petroleum Products Bulk Storage and Distribution 0.100 0.100 0.750
Downstream Oil and Gas Industry Refined Petroleum Product Pipelines 1.000 1.000 1.000
Downstream Oil and Gas Industry Natural Gas Distributiona 1.000 1.000 1.000
Downstream Oil and Gas Industry Other (Downstream Oil and Gas Industry) 0.743 0.641 0.628
Upstream Oil and Gas Industry Accidents and Equipment Failures
Upstream Oil and Gas Industry Disposal and Waste Treatment
Upstream Oil and Gas Industry Heavy Crude Oil Cold Productiona
Upstream Oil and Gas Industry Light Medium Crude Oil Productiona 1.000 1.000 1.000
Upstream Oil and Gas Industry Natural Gas Production and Processinga 1.000 1.000 1.000
Upstream Oil and Gas Industry Natural Gas Transmission and Storagea 1.000 1.000 1.000
Upstream Oil and Gas Industry Oil Sands In-Situ Extractiona 1.000 1.000 1.000
Upstream Oil and Gas Industry Oil Sands Mining and Extractionb 0.658 0.447 0.680
Upstream Oil and Gas Industry Bitumen and Heavy Oil Upgradingb 0.677 0.428 0.631
Upstream Oil and Gas Industry Petroleum Liquids Storagea 1.000 0.831 0.831
Upstream Oil and Gas Industry Petroleum Liquids Transportation
Upstream Oil and Gas Industry Well Drilling/Servicing/Testing
Electric Power Generation (Utilities)
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Coal 0.578 0.293 0.484
Diesel 0.967 0.962 0.943
Natural Gas 0.909 0.663 0.902
Waste Materials 0.734 0.54 0.76
Other (Electric Power Generation) 0.735 0.608 0.924
Manufacturing
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Abrasives Manufacturing 0.415 0.231 0.669
Bakeries 0.861 0.744 0.76
Biofuel Production
Chemicals Industry Chemical Manufacturing 0.737 0.595 0.754
Chemicals Industry Cleaning Compound Manufacturing 1 1 1
Chemicals Industry Fertilizer Production 0.575 0.235 0.52
Chemicals Industry Paint and Varnish Manufacturing 0.919 0.564 0.701
Chemicals Industry Petrochemical Industry 0.894 0.424 0.587
Chemicals Industry Plastics and Synthetic Resins Fabrication 0.791 0.566 0.744
Chemicals Industry Other (Chemical Industry) 0.485 0.465 0.886
Electronics 0.958 0.833 0.834
Food Preparation 0.651 0.409 0.634
Glass Manufacturing 0.836 0.755 0.919
Grain Industries Grain Processing
Grain Industries Warehousing and Storage
Metal Fabrication 0.747 0.59 0.771
Plastics Manufacturing 0.731 0.474 0.817
Pulp and Paper Industry Pulp and Paper Product Manufacturing 0.737 0.56 0.757
Pulp and Paper Industry Converted Paper Product Manufacturing 0.805 0.64 0.773
Textiles 1 1 0.759
Vehicle Manufacture (Engines, Parts, Assembly, Painting) 0.694 0.427 0.748
Wood products Panel Board Mills 0.596 0.361 0.589
Wood products Sawmills 0.423 0.197 0.451
Wood products Other (Wood Products) 0.688 0.549 0.732
Asbestos Industryc 0.373 0.141 0.428
Rubber Manufacturingc 0.638 0.402 0.602
Ship & Boat Building & Repairingc 0.510 0.076 0.151
Asphalt Shingle and Coating Material Manufacturingc 0.851 0.701 0.801
Other (Manufacturing) 0.645 0.359 0.503
Transportation and Mobile Equipment
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Air Transportation
Heavy-Duty Diesel Vehicles
Heavy-Duty Gasoline Vehicles
Heavy-Duty LPG/NG Vehicles
Light-Duty Diesel Trucks
Light-Duty Diesel Vehicles
Light-Duty Gasoline Trucks
Light-Duty Gasoline Vehicles
Light-Duty LPG/NG Ttrucks
Light-Duty LPG/NG Vehicles
Marine Transportation
Motorcycles
Off-road Diesel Vehicles and Equipment
Off-road Gasoline/LPG/CNG Vehicles and Equipment
Rail Transportation
Tire Wear and Brake Lining
Transportation and Mobile Equipment
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Air Transportation
Heavy-Duty Diesel Vehicles
Heavy-Duty Gasoline Vehicles
Heavy-Duty LPG/NG Vehicles
Light-Duty Diesel Trucks
Light-Duty Diesel Vehicles
Light-Duty Gasoline Trucks
Light-Duty Gasoline Vehicles
Light-Duty LPG/NG Ttrucks
Light-Duty LPG/NG Vehicles
Marine Transportation
Motorcycles
Off-road Diesel Vehicles and Equipment
Off-road Gasoline/LPG/CNG Vehicles and Equipment
Rail Transportation
Tire Wear and Brake Lining
Agriculture
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Animal Production
Crop Production Harvesting
Crop Production Inorganic Fertilizer Application
Crop Production Sewage Sludge Application
Crop Production Tillage Practices
Crop Production Wind Erosion
Fuel Use 0.646 0.503 0.749
Commercial / Residential / Institutional
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Cigarette Smoking
Commercial and Institutional Fuel Combustion 0.761 0.581 0.599
Commercial Cooking
Construction Fuel Combustion
Home Firewood Burning
Human
Marine Cargo Handling 0.396 0.147 0.365
Residential Fuel Combustion
Service Stations
Other (Commercial / Residential / Institutional)
Incineration and Waste
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Crematoriums 1.000 1.000 1.000
Waste Incineration Municipal Incineration 0.737 0.680 0.913
Waste Incineration Residential Waste Burning
Waste Incineration Sewage Sludge Incineration
Waste Incineration Other (Waste Incineration) 0.718 0.359 0.479
Waste Treatment and Disposal Landfills 0.778 0.603 0.743
Waste Treatment and Disposal Municipal Wastewater Treatment and Discharge 0.806 0.780 0.955
Waste Treatment and Disposal Specialized Waste Treatment and Remediation 0.778 0.603 0.743
Waste Treatment and Disposal Biological Treatment of Waste 1.000 1.000 1.000
Waste Treatment and Disposal Waste Sorting and Transfer 0.800 0.200 0.250
Paints and Solvents
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Dry Cleaning 1.000 1.000 1.000
General Solvent Used Varies Varies Varies
Printingd Varies Varies Varies
Surface Coatings 1.000 1.000 1.000
Dust
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Coal Transportation
Construction Operations 0.800 0.200 0.250
Mine Tailings
Paved Roads
Unpaved Roadse 0.265 0.027 0.100
Fires
Sector Subsector PM10 ratio PM2.5 ratio PM2.5/PM10 ratio
Prescribed Burning
Structural Fires

Notes

Based on the most recent facility-reported data from NPRI.

a Adapted from Clearstone Engineering Ltd (2014).

b Adapted from Clearstone Engineering Ltd (2017). Emissions from Bitumen and Heavy Oil Upgrading and Oil Sands Mining and Extraction are combined together and reported as Oil Sands Mining, Extraction and Upgrading in this report.

c Emissions from these subsectors (Asbestos Industry; Rubber Manufacturing; Ship & Boat Building & Repairing; and Asphalt Shingle and Coating Material Manufacturing) are reported under Other (Manufacturing).

d Values for PM ratios for these categories vary by subsector: Printing and General Solvent Use—values range from 0.786 to 1.0.

e Ratios derived from particulate matter ratios provided in the NPRI Toolbox guidance document entitled Guidance on Estimating Road Dust Emissions from Industrial Unpaved Surfaces.

– PM10 and PM2.5 ratios are not used for these estimates

3.3 In-house emission estimates

The reporting of substances by facilities to the NPRI remains the primary source of data collection on air pollutant emissions for Canada. Sectors with significant sources of facility-reported data (e.g. oil refineries, smelters) are well represented by emissions data from the NPRI.

The completeness of the APEI is assessed by the level of inclusion of all known, quantifiable sources of pollutant emissions in the provincial/territorial and national totals that are attributed to anthropogenic activities. Where NPRI facility-reported data does not provide for complete sector coverage, additional estimates are developed in-house by ECCC. An overall estimation of completeness in this case is related to the availability and reliability of activity data and methodologies used for the in-house estimates.

The development of complementary in-house estimates is not required in sectors where NPRI facility data provides complete coverage of air pollutant emissions (e.g. pulp and paper). To produce a complete inventory of emissions, complementary in-house estimates are necessary for those sectors that have facilities not reporting to the NPRI because they do not meet the reporting threshold (e.g. upstream oil and gas industry, wood products facilities and foundries).

Other sources of air pollutants, such as residential fuel combustion, transportation or fires, are not subject to reporting to the NPRI, and coverage is assured solely through the calculation of in-house emission estimates for these sources.

Although all major sources of air pollutant emissions are included in the APEI, a number of sources are not included in the national inventory, such as the burning of agricultural wastes and demolition activities in the construction industry.

In-house estimates are calculated with information such as production data and activity data, using various estimation methodologies, emission models and emission factors.Footnote 1 Calculations of in-house estimates are based on the latest data available at the time of inventory development. When possible, the data are updated each year. These emission estimates are at the provincial, territorial and national level rather than at any specific geographic location. The APEI uses in-house estimates for the following emission sources:

Table 3–1 illustrates the sectors and subsectors of the APEI for which emissions are based on in-house estimates and provides the activity data year on which the 2018 in-house estimate is based.

Detailed information on in-house estimation methodologies is presented in Annex 2.

3.4 Reconciliation

In several sectors, such as the upstream oil and gas industry, estimation of total emissions involves combining estimates provided by facilities with estimates developed in-house by ECCC. To prevent double counting of emissions and to confirm that the APEI includes all emissions, a comparison and reconciliation of emission estimates from various sources is performed for each pollutant, industry sector and geographical region, as appropriate.

3.4.1 General procedures

The approach for reconciling facility-reported data and in-house estimates from a province, sector and subsector and for a specific pollutant is as follows:

Equation 3–4

If, InHouseEstimateTotal ≥ FacilityReportedDataTotal

Then, InHouseEstimateREC = InHouseEstimateTotal - FacilityReportedDataTotal

Equation 3–5

If, InHouseEstimateTotal ≤ FacilityReportedDataTotal

Then, InHouseEstimateREC = 0

Some points to consider:

3.4.2 Wood Products

Particulate matter emissions (TPM, PM10 and PM2.5) from Sawmills and Panel Board Mills (Wood Products sector) were not reconciled using the procedure described in section 3.4.1. Rather, NPRI facility-reported data from Sawmills and Panel Board Mills were used to characterize the entire industry. The facility-reported data, together with a number of production indicators, were used to estimate the PM emissions from facilities that are not required to report to the NPRI. The sum of the resulting emission estimates represents the total emissions for these subsectors. All other pollutants were reconciled at the subsector and provincial level according to the standard procedure and equations outlined in section 3.4.1.

3.4.3 Dry Cleaning, General Solvent Use, Printing and Surface Coatings

The in-house estimates in the Dry Cleaning, General Solvent Use, Printing, and Surface Coatings sectors (Paints and Solvents source category) include a total of 92 different kinds of solvents and applications. The challenge is to reconcile the in-house estimates with facility-reported data, which includes a variety of sources (solvent use as well as processes, fuel combustion, road dust, etc.) grouped under the same NAICS. Given this sector’s complexity, reconciliation of in-house estimates with facility-reported data from the NPRI requires that several steps be performed by a specially designed database application (Cheminfo Services, 2016):

  1. allocating the solvent use in-house estimates to the 4-digit NAICS level from the NPRI
  2. allocating the NPRI VOC inventory totals at the 4-digit NAICS level to “Process” and “Solvent” type emissions
  3. subtracting the “Solvent” type NPRI emissions from the solvent in-house emissions estimates

If subtraction of the facility-reported data from the in-house estimates for a certain solvent use yields a small negative value, the emission estimate for that in-house estimate is set to zero. However, if the reconciliation yields a large negative value, examination/verification of both the in-house estimates and the facility-reported data and the allocation percentages for that solvent use is performed, and the estimates are adjusted accordingly.

3.4.4 Mercury in products (Hg)  

Mercury can be released to air throughout the life cycle of mercury-containing products, including during manufacture, distribution, use, disposal, transportation and final disposition, as well as through waste streams. Releases can also result from breakage and processing. As such, reconciliation of Hg air emissions from mercury in products with NPRI facility-reported data involves a review and characterization of the source of the Hg air emissions included in the facility-reported estimate to ensure that the Hg emissions estimated through the life-cycle approach are not duplicated in the facility-reported.

3.5 Data quality control

Quality control for the inventory takes place at each step of the process, in three main phases. In phase 1, quality control is performed on the most recently submitted NPRI facility-reported data, prior to inclusion of the data in the estimates. Phase 2 of the quality control occurs on the in-house estimates at a sub-sectoral level, while phase 3 is performed on the final database of reconciled and compiled emissions.

3.5.1 Phase 1: facility-reported emissions data

The quality control process involves a system of documented activities and procedures performed to identify data outliers, inconsistencies, missing data, inaccuracies and errors. It includes communications with facilities to resolve identified issues. The quality control process is adapted where necessary such that category-specific or sector-specific quality control procedures are applied, as appropriate.

An essential part of the quality control exercise is to identify missing NPRI facility reports/reporters and the assessment of new reports/reporters, to ensure that the correct data are captured.

The identification of outliers (i.e. reports that significantly depart from comparable NPRI facility-reported data) is of critical importance to ensure the usability of the NPRI facility-reported data. Identification, facility follow-up and resolution of such issues are conducted at the earliest stage of the quality control review.

Potential outliers are defined as any NPRI facility report that:

The quality control review includes analysis of:

Quality control checks are also performed on facility information. These checks include the verification of reported NAICS codes, facility identification numbers and geographical information (i.e. city, province, address and latitude/longitude).

Where unresolved issues persist, any updates to the data will be reflected in the next inventory edition.

3.5.2 Phase 2: in-house emission estimates

The objective of Phase 2 of the quality control process is to identify and verify inconsistencies in the APEI at the subsector level. A series of verification and quality control checks are undertaken on the in-house emission estimates of the current year to ensure quality, accuracy and consistency. The following are verified:

3.5.3 Compiled Air Pollutant Emission Inventory

Finally, phase 3 includes all the tests performed once the estimates are reconciled and compiled in a final database. Trend analysis graphics as well as recalculations graphics are produced to analyse the accuracy of the estimates. Any significant changes from year to year and any recalculated emissions are identified and explained.

3.6 Recalculations

Emission recalculation is an essential practice in the maintenance of an up-to-date air pollutant emissions inventory. The APEI is continuously updated with improved estimation methodologies, statistics and more recent and appropriate emission factors. As new information and data become available, previous estimates are updated and recalculated to ensure a consistent and comparable trend in emissions. Recalculations of previously reported emission estimates are common for both in-house estimates and facility-reported emission data. More information on recalculations is provided in Annex 3.

3.7 References

Cheminfo Services. (2016). Compilation of volatile organic compound (VOC) emissions from the use of solvents in Canada: Inventory update. VOC emission trends compilation: 2005 to 2017, Final report. Unpublished report. Markham (ON): Cheminfo. Prepared for Environment and Climate Change Canada.

[EEA] European Environment Agency. 2016. EMEP/EEA Air Pollutant Emission Inventory Guidebook 2016. Technical Guidance to Prepare National Emission Inventories. Luxembourg: Publications Office of the European Union. EEA Report No. 21/2016.

Statistics Canada. (2017). North American Industry Classification System (NAICS) Canada 2017 Version 3.0, Ottawa (ON): Statistics Canada.

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