Canada’s Air Pollutant Emissions Inventory Report 2022: annex 3
Recalculations
Emission recalculation is an essential practice in the maintenance of up-to-date and consistent trends in air pollutant emissions. The Air Pollutant Emissions Inventory (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. Circumstances that warrant a change or refinement of data and/or methods include the:
- correction of errors detected by quality control procedures
- incorporation of updates to activity data including changes to data sources
- re-allocation of activities to different categories (which will affect sub-totals)
- refinements of methodologies and emission factors
- inclusion of categories previously not estimated (which improves inventory completeness)
Resubmissions of facility-reported data previously reported to the National Pollutant Release Inventory (NPRI) can also result in revised historical estimates. Generally, these recalculations by facilities are completed for only a few years in their historical emissions.
In contrast, new activity data are incorporated into the in-house estimates as they become available, and these updates are reflected in the trends on an ongoing basis. Updated trends, based on updated facility-reported data and in-house estimates, are published on a yearly basis. For example, the calculation of emissions from commercial fuel combustion, residential fuel combustion, Agricultural Fuel Combustion and Construction Fuel Combustion sectors rely on the latest fuel use quantities from the Statistics Canada annual publication Report on Energy Supply and Demand in Canada (RESD) (Statistics Canada, n.d.[a]).
The following in-house emissions estimates were recalculated for the 2022 edition of the APEI. Brief descriptions of the recalculations and the impacts on emission levels are provided in Table A3–1 to Table A3–7.
- Ore and Mineral Industries: Rock, Sand and Gravel; Concrete Batching and Products; Foundries
- Oil and Gas Industry: Accidents and Equipment Failures; Heavy Crude Oil Cold Production; Light/Medium Crude Oil Production; Natural Gas Distribution; Natural Gas Production and Processing; Natural Gas Transmission and Storage; Oil Sands In-Situ Extraction; Oil Sands Mining, Extraction and Upgrading; Petroleum Liquids Transportation
- Manufacturing: Bakeries; Grain Industry
- Transportation and Mobile Equipment: Rail Transportation
- Agriculture: Agricultural Fuel Combustion; Animal Production; Crop Production
- Commercial/Residential/Institutional sources: Commercial and Institutional Fuel Combustion; Construction Fuel Combustion; Home Firewood Burning; Residential Fuel Combustion
- Incineration and Waste: Waste Incineration; Crematoriums; Composting; Landfills
In Table A3–1 to Table A3–7, the term “significant” refers to changes greater than ±10% in emission levels.
| Sector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Rock, Sand and Gravel (under Mining and Rock Quarrying) | TPM, PM10, PM2.5 | A methodological change has occurred for the Rock, Sand and Gravel area source model to follow the emission factors available from the EMEP/EEA 2019 Guidebook. In addition, the activity data has been updated to include stone production data; while the sand and gravel production data have been updated with the latest time series information provided by Statistics Canada’s Annual Mineral Production Survey. Finally, the point source component of this sector has been updated with additional National Pollutant Release Inventory (NPRI) facilities for this inventory. | The changes for TPM ranged from an increase of 174% to 277%. For PM10 the changes ranged from an increase of 164% to 263%. Finally, for PM2.5 the changes ranged from a decrease in 10% to an increase in 42% |
| Concrete Batching and Products (under Cement and Concrete Industry) | TPM, PM10, PM2.5, Pb, Cd | Concrete Batching and Products in-house emission estimates were recalculated for a few reasons. Firstly, the domestic consumption of Portland Cement previously only considered production and exports; this has been corrected to include imports of Portland Cement. In addition, the population data and activity data has been updated for the entire time series. Lastly, the activity data source for Portland Cement production has been updated from Statistics Canada’s Annual Survey of Cement, which was discontinued in 2018, to Environment and Climate Change Canada’s Greenhouse Gas Reporting Program for 2019–2020. | The recalculations did not result in changes greater than ±10% at the national level; the range of national impact is from -0.02% to 7%, depending on the pollutant and on the year. Sectorally, the impact ranges from a decrease of 7% in 2004 to an increase of 15% in 2010 for TPM, PM10, PM2.5, Pb and Cd. |
| Foundries | TPM, PM10, PM2.5, SOX, NOX, CO and VOC | A methodological change was completed for the ferrous foundries emission estimates. The emission factors were updated to reflect the current suggested values from the U.S. EPA AP-42 and newly acquired activity data from Quebec was incorporated. | The recalculations resulted in minor changes of less than 0.1% per year at the national level, but emissions decreased for all impacted pollutants in the category for the entire time series (1990-2020). |
| Sector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Accidents and Equipment Failures (under Upstream Oil and Gas Industry) | VOCs | Recalculations occurred to surface casing vent flow emissions from 1990 through 2019 as a result of methodological changes in other sectors. Where applicable, these methodological changes included the reallocation of surface casing vent flow emissions from accidents and equipment failures to the corresponding oil and gas production sector where they occurred. | The recalculations resulted in significant changes in VOCs at the national level from 1990 through 2019. Emissions decreased in each year, with the largest difference in 2014: -92 248 t, -63.7%. |
| Heavy Crude Oil Cold Production (under Upstream Oil and Gas Industry) | CO, NOx, VOCs, SOx, PM2.5, PM10, TPM | Recalculations occurred as a result of methodological changes to fuel combustion, flaring and venting emissions estimates from 1990 through 2019. Further methodological changes to surface casing vent flow emissions enabled their reallocation from accidents and equipment failures to this sector, resulting in changes from 1990 through 2019. | The recalculations resulted in significant changes to emissions at the national level in 2005 for CO (-1 217 t, -11.1%), from 2013 through 2019 for VOCs (largest difference in 2014: -4 888 t, -20.4%), and from 2001 through 2019 for PM2.5, PM10, and TPM (largest, equivalent differences of -436 t, -78.5% in 2005). SOx emissions increased significantly from 1997 through 2005 (largest difference in 1998: +76 t, 16.2%) and decreased significantly from 2013 through 2019 (largest difference in 2017: -483 t, -18.6%). The recalculations resulted in decreases of NOx emissions ranging from 0.2% to 2.9%. |
| Light/Medium Crude Oil Production (under Upstream Oil and Gas Industry) | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3 | Recalculations occurred as a result of methodological changes to fuel combustion, flaring and venting emissions estimates from 1990 through 2019. Further methodological changes to surface casing vent flow emissions enabled their reallocation from accidents and equipment failures to this sector, resulting in changes from 1990 through 2019. | The recalculations resulted in changes to emissions at the national level from 1990 through 2019 for SOx (largest difference in 2014: +20 034 t, +153%), for VOCs (largest difference in 2017: +47 835 t, +13.7%), for TPM, PM10, and PM2.5 (largest differences in 1998: +726.5 t, +15.1%). For all other pollutants, this recalculation resulted in increases of less than 10%. |
| Natural Gas Distribution (under Downstream Oil and Gas Industry) | CO, NOx, VOCs, SOx, PM2.5, PM10, TPM | Recalculations occurred because of updated activity data for pipeline lengths in 2019 (Statistics Canada, 2021). | The recalculations resulted in minor changes of less than ±10% at the national level in 2019. In 2019 emissions of CO, NOx, PM2.5, PM10, and TPM each increased by 0.1%, emissions of SOx increased by 0.5%, and emissions of VOCs decreased by 0.3%. |
| Natural Gas Production and Processing (under Upstream Oil and Gas Industry) | CO, NOx, VOCs, SOx, TPM, PM10, PM2.5, NH3 | Recalculations occurred as a result of methodological changes to fuel combustion, flaring and venting emissions estimates from 1990 through 2019. Further methodological changes to surface casing vent flow emissions enabled their reallocation from accidents and equipment failures to this sector, resulting in changes from 1990 through 2019. | These recalculations resulted in changes to emissions at the national level from 1990 through 2019 for VOCs (largest difference in 2009: +8 361 t, +14.3%). For all other pollutants, these recalculations did not result in changes greater than ±10%. |
| Natural Gas Transmission and Storage (under Upstream Oil and Gas Industry) | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO | Recalculations occurred in 2018 because NPRI reported data was updated for certain facilities and in 2019 because of updated activity data. (Statistics Canada, 2021; Statistics Canada, n.d.[b]) | For all pollutants, this recalculation did not result in an emissions change of greater than ±10%. In 2018, CO and NOx emissions increased by 5.9% and 6.2%, respectively. In 2019, emissions of each pollutant increased (largest increase for SOx: 2.3%), except for a decrease of 0.6% in NOx emissions. |
| Oil Sands In-Situ Extraction (under Upstream Oil and Gas Industry) | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO | Recalculations occurred as a result of methodological changes to fuel combustion, flaring and venting emissions estimates from 2012 through 2019. Further methodological changes to surface casing vent flow emissions enabled their reallocation from accidents and equipment failures to this sector, resulting in changes from 1990 through 2019. | Recalculations resulted in significant changes to emissions at the national level from 2012 through 2019 for TPM, PM10, and PM2.5 (largest difference in 2017: -419 t, -31.6%) and from 1990 through 2019 for VOCs (largest difference in 2017: -2303 t, -16.9%). For all other pollutants, this recalculation did not result in an emissions change of greater than ±10% (differences of less than ±1% for SOx, and NOx, largest difference in 2017 for CO: -1 171 t, -4.2%). |
| Oil Sands Mining, Extraction and Upgrading (under Upstream Oil and Gas Industry) | CO, NOx, SOx, TPM, PM10, PM2.5, VOCs, Hg, B(a)p, B(b)f, B(k)f, I(1,2,3-cd)p | Recalculations occurred because NPRI reported data was updated for certain facilities for 2018 and 2019. | Recalculations resulted in significant changes to emissions at the national level in 2019 for TPM (-3 636 t, -21.4%), for PM10 (-1 549 t, -17.3%), for VOCs (-6 515 t, -13.4%), and in 2018 for VOCs (+8 506 t, +22.4%). For all other pollutants, this recalculation resulted in decreases of less than 10%. |
| Petroleum Liquids Transportation (under Upstream Oil and Gas Industry) | VOCs | Recalculations occurred in 2018 and 2019 because of updated activity data (NB NRED, 2021). | This recalculation did not result in an emissions change of greater than ±10%. |
| Sector/subsector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Bakeries | VOCs | Recalculations occurred for 2017 to 2019 due to the use of revised population data for these years and revisions to bakeries activity data for 2018 and 2019. | The recalculations resulted in minor decreases in VOC emissions for 2017 to 2019 , with a maximum impact of -3.2 t (-0.06%) in 2019. |
| Grain Industry | TPM, PM10, PM2.5 | Corrections to point sources activity data from the National Pollutant Release Inventory (NPRI) were implemented for years after 2015. Corrections to the calculation of area source emission estimates in 2019. |
These changes had no impact to emissions for years 1990 or 2005, but decreased emissions in 2019 by 9.1 kt (-14%) for TPM, 5.6 kt (-29%) for PM10, and 0.4 kt (-13%) for PM2.5. |
| Sector | Pollutant(s) | Fuel | Description | Impact on emissions |
|---|---|---|---|---|
| Rail Transportation | B(a)p, B(b)f, |
Diesel Fuel Oil |
The rail transportation model was updated for the 2022 inventory. The provincial activity data has been updated to reflect the amount of fuel consumed within a geographical region whereas the previous model was based on fuel supplied to a geographical region. |
The recalculations resulted in changes from 2005 to 2019. From 2005 to 2017 the recalculations resulted in minor changes within ±0.3% For 2018, the recalculations resulted in minor changes between -1.4% and +6.4%. For 2019, the recalculations resulted in minor changes in the emissions of: |
| Sector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Animal Production | NH3 | Recalculations are primarily due to a correction to the nitrogen excretion rate for Swine in response to a corrigenda to Volume 4, Chapter 10 of the 2006 IPCC Guidelines. To a lesser extent, recalculations to NH3 occurred due to changes in the spatial distribution of livestock. |
The changes resulted in a decrease in NH3 emissions of 6.8 kt (-2%) in 1990, 9.6 kt (-3%) in 2005, and 10.5 kt (-4%) in 2019. |
| Animal Production | TPM, PM10, PM2.5 | Recalculations are primarily due to the integration of updated earth observation products in deriving activity data, leading to a spatial reallocation of livestock populations and as a consequence weighting of emission factors. | The changes were minor in all years, decreasing emissions by <0.01%. |
| Animal Production | VOCs | Minor recalculations occurred as a result of spatial reallocation of cattle populations and as a consequence weighting of emission factors. | The changes increased emissions by <10 tonnes (<0.01%) for all years. |
| Crop Production | NH3 | The primary recalculation in 2019 was due to a correction to fertilizer activity data provided by Statistics Canada. Recalculations to NH3 also occurred in all years due to the revision of the FracGASm parameter from 0.20 to 0.21 based on the 2019 Refinement to the 2006 IPCC Guidelines, and due to changes in the spatial distribution of crop areas. |
The modification of this parameter resulted in an increase in NH3 emissions of 0.2 kt (+0.3%) in 1990, 0.3 kt (+0.3%) in 2005, and 4.2 kt (+2.5%) in 2019. |
| Crop Production | TPM, PM10, PM2.5 | Recalculations are primarily due to the integration of updated earth observation products in AAFC activity data, leading to a reallocation of crop types influencing the weighting of PM emission factors. | The resulting recalculations were: TPM: -36 kt (-0.5%) in 1990, +7.8 kt (+0.2%) in 2005, and -310 kt (-8%) in 2019. PM10: -19 kt (-0.8%) in 1990, +2.4 kt (+0.1%) in 2005, and -141 kt (-9%) in 2019. PM2.5: -3.6 kt (-0.5%) in 1990, +0.78 kt (+0.2%) in 2005, and -31 kt (-8%) in 2019. |
| Agricultural Fuel Combustion | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3, Pb, Cd, Hg, dioxins/furans, B(a)p, B(b)f, B(k)f, I(cd)p, HCB | Recalculations are due to activity data updated to a more recent edition of the RESD. The majority of the change in this source is due to a correction related to heavy fuel oil consumption in agriculture back to 2007, which has caused a decrease in emissions for most pollutants. Those pollutants that saw an increase in emissions were impacted by a correction in coal consumption for 2019. | The recalculations did not result in changes in emission levels for any of the pollutants in 1990. For the year 2019, pollutant emissions recalculations were: Pb: -24 kt (-48%) D/F: 0.3 kt (540%) B(b)f: -0.03 kt (-34%) B(k)f: -0.03 kt (-34%) I(1,2,3-cd)p: -0.05 kt (-42%) HCB: 0.8 kt (value where there was none in previous submission) CO: 165 kt (17%) SOx: -5 400 kt (-96%) NOx: -990 kt (-26%) PM10: -90 kt (-22%) Other pollutant emissions changed less than ±10%. |
| Sector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Commercial and Institutional Fuel Combustion | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3, Pb, Cd, Hg, dioxins/furans, B(a)p, B(b)f, B(k)f, I(cd)p, HCB | Recalculations occur between 1996 and 2019. Recalculations are due to activity data updated to a more recent edition of the RESD as well as removal of data that was double counted. | The recalculations did not result in changes in emission levels for any of the pollutants in 1990. For the year 2019, pollutant emissions changed by less than ±10%, with the exception of SOx which showed an 11% decrease. |
| Construction Fuel Combustion | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3, Pb, Cd, Hg, dioxins/furans, B(a)p, B(b)f, B(k)f, I(cd)p, HCB | Recalculations are due to activity data updated to a more recent edition of the RESD. | The recalculations did not result in changes in emission levels for any of the pollutants in 1990. For the year 2019, pollutant emissions changed by less than ±10%, with the exception of D/F increasing by 16%, VOCs increasing by 12%; and, SOx decreasing by 41%. |
| Home Firewood Burning | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3, Pb, Cd, Hg, dioxins/furans, B(a)p, B(b)f, B(k)f, I(cd)p, HCB | Recalculations are due to updated activity data from Statistic Canada from the Households and the Environment Survey (Statistics Canada, n.d.[c]) for 2018 and 2019. | The recalculations did not result in changes in emission levels for any of the pollutants in 1990. For the year 2019, pollutant emissions changes fluctuated between 9% and -30%. |
| Residential Fuel Combustion | TPM, PM10, PM2.5, SOx, NOx, VOCs, CO, NH3, Pb, Cd, Hg, dioxins/furans, B(a)p, B(b)f, B(k)f, I(cd)p, HCB | Recalculations are due to activity data updated to a more recent edition of the RESD; which had updates to this source back to 2013. | The recalculations did not result in changes in emission levels for any of the pollutants in 1990. For the year 2019, SOx emissions decreased by 22%. The remaining pollutant emissions changed by less than ±10%. |
| Sector | Pollutant(s) | Description | Impact on emissions |
|---|---|---|---|
| Waste Incineration (hazardous waste, medical waste, municipal, sewage sludge, Other Waste Incineration) | PM10, PM2.5, SOX, TPM,CO, NOX, VOC, Pb, D/F, B(a)p, I(1,2,3-cd)p, B(k)f, NH3, B(b)f, Hg, Cd, HCB | The method for estimating emissions from incineration has been wholly updated. The area-source models have been removed in favour of facility-reported data, with facility-level emissions modelled where necessary for gap filling. Facility level emissions are based on implied emission factors where possible, then in order of preference technology-specific emission factors are used, followed by generic emission factors. Quantities of waste incinerated are gathered through voluntary surveys. For medical waste incineration, quantities incinerated are from CCME (2006) and extrapolated based on population change trends. | The recalculation and method change resulted in variable impacts for waste incineration emission estimates. Both overall total emissions and emission trends have changed. The differences between this inventory and previous vary by pollutant. For all incineration sub-classes combined: 1990: PM10: -64%, PM2.5: -64%, SOX: -67%,TPM: -44%, CO: +85%, NOX: +22%, VOC: -77%, Pb: 85%, D/F: -69%, B(a)p: +65%, I(1,2,3-cd)p: -7%, B(k)f: +9%, NH3: -98%, B(b)f: +556%, Hg: +26%, Cd: -99%, HCB: -82% 2019: PM10: +89%, PM2.5: +79%, SOX: -61%, TPM: -24%, CO: -81%, NOX: +24%, VOC: -47%, Pb: -45%, D/F: +4 733%, B(a)p: +100%, I(1,2,3-cd)p: Newly > 0, B(k)f: Newly > 0, NH3: -73%, B(b)f: Newly > 0, Hg: -83%, Cd: -48%, HCB: +288% |
| Crematoriums | CO, NOx, Hg | The emission factors used for CO and NOx have been corrected to match the reference. Santarsiero et al. (2005) as referenced in the EMEP/EAA air pollutant emission inventory guidebook now used. The Hg emission factors for releases from body tissue from cremation have been updated to follow the methodology used by the U.S. EPA (Reindl, 2012) . By doing so, we can account for emissions from dental amalgams from the cremation process separately. This is possible by incorporating the Hg emissions from dental amalgams used in theHg in Products model. Prior to this inventory, the Hg in Products estimates for cremation were not included in our inventory. | At a national level, the recalculations for 1990–2019 years increased emissions of all pollutants. CO increased by 40% for 1990, 40% for 2005 and 42% for 2019. NOx increased by 581% for 1990, 582% for 1990, 582% for 2005, and 592% for 2019. And Hg emissions increased by 82% in 1990, 82% in 2005 and 84% in 2019. |
| Composting (under Biological Treatment of Waste) | NH3, VOCs | An online facility level review was undertaken for the 2022 inventory to update amount of waste accepted, types of feedstocks accepted, method used and controls applied (when available). In addition, a mapping error was identified for provincial allocation for VOCs in the area source model used for the previous iteration of the APEI which has now been fixed. | At the national level, the facility level review resulted in recalculations that ranged from a 18% decrease to a 12% increase throughout the time series for NH3. For VOCs, the facility level review ranged in a decrease of 14% up to a 12% increase throughout the time series. In addition, the mapping error that was corrected for this inventory resulted in relative changes in emissions estimates by province or territories of more than 100% for VOCs for the full time series. Please note NH3 was not impacted by this mapping correction. |
| Landfills (under Waste Treatment and Disposal) | VOCs | The VOC estimates from landfills are derived from estimates of landfill gas generated. Two errors were corrected. An error in estimates of waste landfilled in the previous inventory where waste incinerated was included as part of the total landfilled from 1990 to 2019 has been corrected. A calculation error where the VOC was previously calculated from the volume of methane in landfill gas as opposed to total landfill gas volume has been corrected for all years. | The corrections resulted in VOC emission estimates to become 12% lower for 1990 and 10% lower for 2019 than previously estimated for landfills. |
References, Annex 3, Recalculations
[CCME] Canadian Council of Ministers of the Environment. 2006. Review of dioxins and furans from incineration in support of a Canada-wide standard review. Report prepared for the Dioxins and Furans Incineration Review Group by A.J. Chandler & Associates Ltd.
[NB NRED] New Brunswick Natural Resources and Energy Development. 2021. Monthly Production Statistics. [cited 2021 Oct 18]. [PDF]
Statistics Canada. 2021. Gas Pipeline Distance, by Province. Unpublished data.
Statistics Canada. No date[a]. Report on energy supply and demand in Canada (Annual), Catalogue No. 57 003 X.
Statistics Canada. No date[b]. Table 25-10-0057-01 (formerly CANSIM 129-0005) – Canadian natural gas storage, Canada and provinces (database).
Statistics Canada. No date[c]. Households and the Environment Survey. [last updated 2020 Nov 30].
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