Canada’s Air Pollutant Emissions Inventory Report: annex 2 part 1

Inventory development

A2.1  Overview of the compilation process

The process of compiling emission estimates for the Air Pollutant Emissions Inventory (APEI) consists of developing in-house estimates, categorizing facility-reported data and, where necessary, reconciling the in-house estimates and the facility-reported data in a central database (Figure A2-1).

First, facility-reported data are compiled with the extraction of National Pollutant Release Inventory (NPRI) facility and emissions data from the verified NPRI database. New facilities are identified in the extracted data and classified among the APEI sector and subsector categories according to the nature of their activities. A quality control process is performed on the point source data prior to its inclusion in the APEI. A summary of this quality control process is presented in Chapter 4. A list of the facility-reported data is then produced and transferred to a central APEI database.

Figure A2-1: Overview of the annual Air Pollutant Emissions Inventory Compilation process

Figure A2-1 (See long description below)
Long description for Figure A2-1

Figure A2-1: This flowchart provides an overview of Canada’s annual Air Pollutant Emissions Inventory (APEI) compilation process. Facility-reported data from the National Pollutant Release Inventory (NPRI) are compiled with in-house estimates. New facilities are identified in the NPRI and classified among the APEI sector and subsector categories according to the nature of their activities. Next, imputation of unreported particulate matter (PM)-size fractions is performed and a list of the final facility-reported data is produced and transferred to a central database.

While the facility-reported data are compiled, the in-house estimates are calculated. In-house estimates first involves collection and analysis of the latest emission factors and activity data and/or database-driven-emissions models, followed by calculation of the emission estimates.

The next step in the process is elimination of double-counting of emissions between the in-house estimates and facility-reported data by a process of reconciliation. Once the calculated in-house estimates have been transferred to the central database, these estimates are reconciled with the facility-reported data by using an automated database utility. Reconciliation of the in-house estimates for solvent use and Hg emissions with the facility-reported data is carried out separately, and then transferred to the central database.

The final steps in the compilation process involve aggregation of the final facility-reported data and reconciled in-house estimates in the central database to produce draft emissions summaries for quality assurance/quality control and consultation purposes. Any identified issues are addressed and the central database is updated. Final emissions summaries are then produced and the final emissions database is used to fulfill Canada’s international and domestic reporting obligations.


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. Improvements to methods or data are implemented as appropriate, and estimates may be recalculated for part of or across the entire time series. Updated estimates are calculated using new and/or updated activity data. Calculations are typically performed in spreadsheets or database-driven emission models.

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. Reconciliation of the in-house estimates with the facility-reported data is required for sectors or subsectors when both in-house and facility-reported estimates exist (Table A2-1). For 2017, reconciliation was performed for about 25 sectors. More information on reconciliation is available in section A2.5.1.

The final steps in the compilation process involve aggregating all reconciled data in the central database to produce draft emissions summaries for quality assurance/control and consultation purposes. The final emissions database is also used to generate the emissions tables required to fulfill Canada’s international and domestic reporting obligations.

A2.2  In-house estimates

The compilation of in-house estimates relies on information such as production data or activity levels for each sector. Calculations of in-house estimates are based on the latest data available at the time of compilation. When possible, the data are updated each year.

Table A2-1 lists 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 2017 in-house estimate is based.

The in-house emissions estimation methodologies and emission models used in Canada are generally based on those developed by the United States Environmental Protection Agency (U.S. EPA) and adapted to utilize Canadian data, thereby accounting for differences in climate, fuels, technologies and practices. Methods used in Canada’s APEI are therefore generally consistent with those used in the United States or those recommended in the EMEP/EEA Air Pollutant Emission Inventory Guidebook (EEA, EMEP/EEA, 2016).

Tables A2-2 through A2-12 summarize, for each source category, the in-house estimation methodologies for the entire time series. For each source category, these tables provide a short description of:

  • the emission sources and pollutants covered;
  • the general inventory approach; and
  • references for the activity data, emission factors and/or emission models.

Table A2-1:  2017 Air Pollutant Emissions Inventory (APEI)

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 2015
Cement and Concrete Industry Cement Manufacturing x - -
Cement and Concrete Industry Concrete Batching and Products x x 2017
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 2017 (Hg in Products)
Iron and Steel Industry Steel Recycling x x 2017 (Hg in Products)
Iron and Steel Industry Other (Iron and Steel Industry) - x 2006
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 2017
Mining and Rock Quarrying Silica Production - x 2017
Mining and Rock Quarrying Limestone x x -
Mining and Rock Quarrying Other Minerals (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 - -
Non-Ferrous Refining and Smelting Industry Other (Non-Ferrous Refining and Smelting Industry) x - -
Oil and Gas Industry
Sector Subsector Facility-reported data In-house estimates 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 2016
Downstream Oil and Gas Industry Other (Downstream Oil and Gas Industry) x - -
Upstream Oil and Gas Industry Accidents and Equipment Failures - x 2017
Upstream Oil and Gas Industry Disposal and Waste Treatment - x 2017
Upstream Oil and Gas Industry Heavy Crude Oil Cold Production - x 2017
Upstream Oil and Gas Industry Light/Medium Crude Oil Productionc x x 2017
Upstream Oil and Gas Industry Natural Gas Production and Processingd x x 2017
Upstream Oil and Gas Industry Natural Gas Transmission and Storage x x 2016
Upstream Oil and Gas Industry Oil Sands In-Situ Extraction x x 2017
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 2017
Upstream Oil and Gas Industry Well Drilling/Servicing/Testing - x 2017
Electric Power Generation (Utilities)
Sector Subsector Facility-reported data In-house estimates 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 data In-house estimates Activity data used for in-house estimates
Abrasives Manufacturing - x - -
Bakeries - x x 2017
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 2017 (Hg in Products)
Food Preparation - x - -
Glass Manufacturing - x - -
Grain Industry Grain Processing x x 2017
Grain Industry Warehousing and Storage x - 2017
Metal Fabrication - x - -
Plastics Manufacturing - x - -
Pulp and Paper Industry Pulp and Paper Product Manufacturing x x 2006
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 2017
WoodProducts Sawmills x x 2017
Wood Products Other (Wood Products) x - -
Other (Manufacturing) - x x 2008, 2017 (Hg in Products)
Transportation and Mobile Equipment
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Air Transportation - - x 2017
Heavy-Duty Diesel Vehicles - - x 2017
Heavy-Duty Gasoline Vehicles - - x 2017
Heavy-Duty LPG/NG Vehicles - - x 2017
Light-Duty Diesel Trucks - - x 2017
Light-Duty Diesel Vehicles - - x 2017
Light-Duty Gasoline Trucks - - x 2017
Light-Duty Gasoline Vehicles - - x 2017
Light-Duty LPG/NG Ttrucks - - x 2017
Light-Duty LPG/NG Vehicles - - x 2017
Marine Transportation - - x 2015
Motorcycles - - x 2017
Off-road Diesel Vehicles and Equipment - - x 2017
Off-road Gasoline/LPG/NG Vehicles and Equipment - - x 2017
Rail Transportation - - x 2017
Tire Wear and Brake Lining - - x 2017
Agriculture
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Animal Production - - x 2017
Crop Production Fertilizer Application - x 2017
Crop Production Harvesting - x 2017
Crop Production Tillage Practices - x 2017
Crop Production Wind Erosion - x 2017
Fuel Use - x x 2014
Commercial / Residential / Institutional
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Cigarette Smoking - - x 2017
Commercial and Institutional Fuel Combustion - x x 2017
Commercial Cooking - - x 2016
Construction Fuel Combustion - - x 2017
Home Firewood Burning - - x 2017
Humanf - - x 2017
Marine Cargo Handling - x - -
Residential Fuel Combustion - - x 2014
Service Stations - - x 2017
Other (Commercial / Residential / Institutional)g - - x 2008
Incineration and Waste
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Crematoriums - x x 2015
Waste Incineration Industrial and Commercial Incineration - x 2011
Waste Incineration Municipal Incineration x x 2011
Waste Incineration Residential Waste Burningh - x 2016
Waste Incineration Other (Waste Incineration) - x 2009
Waste Treatment and Disposal Landfills x x 2014
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 data In-house estimates Activity data used for in-house estimates
Dry Cleaning - x x 2016
General Solvent Use - - x 2016
Printing - x x 2016
Surface Coatings - x x 2016
Dust
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Coal Transportation - - x 2015
Construction Operations - - x 2012
Mine Tailings - - x 2006
Paved Roads - - x 2002
Unpaved Roads - x x 2002
Fires
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Prescribed Burning - - x 2015
Structural Fires - - x 2017
Mercury
Sector Subsector Facility-reported data In-house estimates Activity data used for in-house estimates
Mercury in productsi - - x 2017

Notes

x: denotes yes

a All facility-reported data were obtained from the NPRI Reporting Year 2017.

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 (Commercial / Residential / Institutional), are now reported under the Human sector.

g Emissions reported under Other (Commercial / Residential / Institutional) 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 (Commercial / Residential / Institutional) and Landfills. All in-house estimates for Hg in product emissions continue to be estimated and reported under these sectors.

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