Guide for reporting to the National Pollutant Release Inventory 2025-2027

Disclaimers

Should any inconsistencies be found between this guide and the official Canada Gazette, Part I Notice with respect to substances in the National Pollutant Release Inventory for 2025, 2026 and 2027, published on March 8, 2025, the Notice will prevail.

The Chemical Abstracts Service (CAS) Registry Number (CAS RN) is the property of the American Chemical Society, and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the government when the information and the reports are required by law or administrative policy, is not permitted without the prior, written permission of the American Chemical Society.

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1. Introduction

The National Pollutant Release Inventory (NPRI) is Canada’s legislated, publicly accessible inventory of pollutant releases, disposals and recycling. Sections 46–53 of the Canadian Environmental Protection Act, 1999 (CEPA) contain information-gathering provisions that allow the Minister of Environment and Climate Change Canada to require reporting of information on substances. The provisions also require the Minister to establish and publish a national inventory of releases and transfers of pollutants. These provisions under CEPA form the primary legislative basis for the NPRI. 

NPRI information is a major starting point for identifying and monitoring sources of pollution in Canada, and in developing indicators for the quality of our air, land and water. The NPRI helps determine if regulatory or other action is necessary to ensure reductions, and if so, the form that action should take. The NPRI provides Canadians with annual information on releases and transfers from industrial, institutional, commercial and other types of facilities in their communities.

The NPRI reporting requirements for the 2025-2027 reporting years were published in the Notice with respect to substances in the National Pollutant Release Inventory for 2025, 2026 and 2027 in the Canada Gazette, Part I, on March 8, 2025. This guide is designed to assist facility owners and operators in understanding the NPRI reporting requirements, and in determining if they are required to report to the NPRI. It provides a general overview of the reporting requirements for all NPRI substances, and provides information on additional guidance materials that address specific sectors, activities and substances.

The requirements described in this guide apply to the 2025, 2026 and 2027 calendar years. Note that facility owners or operators must consider each year individually when determining if thresholds are met and if reporting is required. Quantities of substances that are released, disposed of, and recycled should be reported by the specified deadline for each year.

2. Reporting deadlines and changes to reporting requirements

2.1 Reporting deadlines

Reporting is mandatory for facilities that meet the requirements of the NPRI Notice published in the Canada Gazette, Part I.

The deadline for reporting to the NPRI for the 2025 calendar year is June 1, 2026. 

The deadline for reporting to the NPRI for the 2026 calendar year is June 1, 2027.

The deadline for reporting to the NPRI for the 2027 calendar year is June 1, 2028.

2.2 Changes to reporting requirements for 2025-2027

2.2.1 New requirements for reporting triarylmethane dyes

The following substances were added to Part 1, Group B, with a 100 kg manufactured, processed, or otherwise used (MPO) threshold and 1% concentration threshold for each substance:

• Basic Violet 3, Chemical abstract service registry number (CAS RN) 548-62-9
• Basic Violet 4, CAS RN 2390-59-2
• Basic Blue 7, CAS RN 2390-60-5 
• MAPBAP Acetate, CAS RN 72102-55-7

C.I. Basic Green 4 (CAS RN 569-64-2) was deleted from Part 1, Group A, and added to Part 1, Group B, with an MPO threshold of 100 kg and 1% concentration threshold. C.I. Basic Green 4 was renamed Malachite Green.

2.2.2 New requirements for reporting benzothiazoles that can form 2-mercaptobenzothiazole

2-Mercaptobenzothiazole (CAS RN 149-30-4) was deleted from Part 1, Group A, of the substance list. A group of 20 benzothiazoles that can form 2-mercaptobenzothiazole (MBT) (see Appendix F for the full list of substance names and CAS RNs), including MBT, was added to Part 1, Group B, of the substance list with a 100 kg MPO threshold and a 0.1% concentration by weight threshold. The thresholds apply to the total of the 20 substances. 

2.2.3 New requirements for reporting long-chain aliphatic amines

Ninety-two long-chain aliphatic amines (see Appendix F for full list of names and CAS RNs) were added to Part 1, Group B, of the substance list with an MPO threshold of 5,000 kg and a concentration threshold of 0.1% by weight. The thresholds apply to the total of the 92 substances.

2.2.4 New requirements for reporting hydrogen cyanide, free cyanide, cyanide salts and cyanide complexes

Free cyanide, cyanide salts and cyanide complexes were added to Part 1, Group B, of the NPRI substance list with a 1,000 kg MPO threshold and a 0.1% concentration by weight threshold. The thresholds apply to the total of the group of substances. Hydrogen cyanide (CAS RN 74-90-8) was deleted from Part 1, Group A, and added to Part 1, Group B, of the substance list with an MPO threshold of 1,000 kg and 0.1% concentration. See Appendix F for the full list of names and CAS RNs included in this substance grouping. 

Please note that hydrogen cyanide (HCN) may be incidentally produced in significant quantities during high-temperature industrial processes, such as carbon black production, petroleum refining, and coke processing. These incidental by-products are required to be included in the ‘manufacture, process or otherwise use’ (MPO) threshold calculation and must be reported to NPRI if the 1,000 kg threshold is met. Concentration thresholds do not apply to by-products.

2.2.5 New requirements for reporting per- and polyfluoroalkyl substances

One hundred sixty-three per- and polyfluoroalkyl substances (PFAS) were added to a new Part 1, Group C, of the substance list. Facilities that meet the employee threshold and that MPO 1 kg or more of a listed PFAS at a concentration of 0.1% by weight or more will be required to report quantities of that PFAS that are released, disposed of and recycled. The mass and concentration thresholds apply to each listed PFAS individually. More information for reporting these substances can be found in section 5.4 of this Guide. 

2.2.6 New requirements for reporting ethylene oxide

Ethylene oxide (CAS RN 75-21-8) was deleted from Part 1A and added to Part 1B of the NPRI substance list, with an MPO threshold of 1 kg and a 0.1% concentration. In addition, the reporting requirements for ethylene oxide now apply to activities related to the education and training of students.

2.2.7 Clarification of the definition for Naphthenic Acid Fraction Compounds (and their salts)

Changes were made to clarify the definition for naphthenic acid fraction compounds (and their salts). No changes were made to the reporting requirements for this substance. The definition found in the Canada Gazette is as follows: 

Carboxylic acids that include chain compounds and compounds with one or more alicyclic ring structures with the general formula C_nH_2n+ZO_xN_αS_β, where “n” indicates the carbon number; “Z” is referred to as the “hydrogen deficiency” (the number of hydrogen atoms that are lost as the structures become more compact) and is zero or a negative, even integer (from -2 to -12); “x” refers to the oxygen number; “α” refers to the nitrogen number; and “β” refers to the sulphur number. Includes diverse polar organic compounds present in bitumen and oil sands process-affected water. This includes several compound classes, including aromatic, adamantine, or diamondoid structures, sulphur- and nitrogen-containing compounds, and oxygenated acids.

3. General information and overview of reporting requirements

3.1 Introduction

This section summarizes the process for reporting to the NPRI, describes the legal basis for the NPRI, provides an overview of the NPRI reporting requirements, provides definitions of terms that are used throughout the guide, and describes the information to be reported that applies to more than one group of substances. This section also provides information on additional resources that are available to assist in determining if a report is required for a facility, and on the methods for estimating quantities of releases, disposals and transfers for recycling. Details on reporting requirements and information to be reported that are specific to substances from Parts 1 through 5 are presented in sections 4 through 9.

3.2 Process for reporting to the NPRI

An NPRI report can be created and submitted to Environment and Climate Change Canada using the online reporting system. Step-by-step instructions for creating and submitting a report are available in the online reporting system and on the NPRI website. 

The owner/operator of a facility must review the specific reporting requirements applicable to their facility to determine if they are required to report to the NPRI. If the requirements are met, then the total quantities of NPRI substances released, disposed of, and transferred for recycling must be reported to the NPRI using the online reporting system, even if the total quantity is zero.

A facility that submitted a report in the previous year but no longer meets NPRI reporting criteria for the current year, is required to submit a “Does Not Meet Criteria (DNMC)” report using the online system by the reporting deadline.

The NPRI reporting process is outlined below:

• Option one: the facility meets reporting requirements for the reporting year:
  1. estimate the quantities of all applicable pollutant categories for the facility for the reporting yea
  2. submit an NPRI Report in the Single Window Information Manager (SWIM)
  3. submit a Sales/Closure/Purchase Report in SWIM, if applicable
  4. keep a record of all information and backup calculation files
• Option two: the reporting requirements are not met but the facility was sold/closed/purchased during the reporting year:
  1. submit a Sales/Closure/Purchase Report in SWIM
  2. keep a record of all information and backup any files
• Option three: the reporting requirements are not met, and the facility was not sold/closed/purchased during that reporting year:
  1. if an NPRI report was submitted the previous year, submit a Does Not Meet Criteria Report and keep a record of all information
  2. if no report was submitted the previous year, no reporting is required

3.3 The Canada Gazette Notice – The legal basis for the NPRI

The legal basis for the NPRI is the Notice with respect to substances in the National Pollutant Release Inventory for 2025, 2026 and 2027 published in the Canada Gazette, Part I (hereafter referred to as “the Notice”). The Notice is published under the authority of subsection 46(1) CEPA. It specifies that any person who owned or operated a facility during the 2025, 2026 or 2027 calendar years, under the conditions prescribed in the Notice, must provide certain information to the Minister of the Environment and Climate Change by the reporting deadline for that calendar year.

Reporting to the NPRI is mandatory. Companies that meet reporting requirements but fail to report, fail to report on time, or knowingly submit false or misleading information, face penalties as listed under section 272 of CEPA. Facilities that did not meet the reporting criteria or were exempt from reporting in previous years should review their status to determine whether they are required to report each year. 

The owner or operator of the facility as of December 31st of the given year is required to report to the NPRI, whether or not the ownership of the facility changes during the calendar year. If operations at a facility are terminated, the last owner or operator of the facility is required to report. An NPRI report may need to be submitted for a facility that is under decommissioning or in care or maintenance mode if the employee and/or substance-specific reporting criteria are met. Once reporting criteria are met for a substance, an NPRI report must be submitted for that substance regardless of the quantities released, disposed of, or transferred (even if the quantity is zero).

The Notice encompasses a wide range of substances and groups of substances (available on the NPRI website in HTML and MS Excel^TM formats), reporting criteria and requirements. It is divided into four schedules with several parts in each: 

1. list of substances:
   • Part 1 lists 373 substances and groups of substances and is divided into groups A, B, and C, based on thresholds and information to be reported (referred to as Part 1A, Part 1B, and Part 1C substances)
   • Part 2 lists 31 individual polycyclic aromatic hydrocarbons (PAHs)
   • Part 3 lists 7 dioxins, 10 furans and hexachlorobenzene (HCB)
   • Part 4 lists 7 criteria air contaminants (CACs)
   • Part 5 lists 62 selected volatile organic compounds (VOCs) and groups of VOCs with additional reporting requirements (speciated VOCs)
2. definitions:
   • provides definitions of the terms used in the Notice
3. reporting criteria:
   • general reporting criteria, including the reporting deadline, the employee threshold, and exclusions and exemptions
   • Parts 1-5 provides criteria for substances listed in the corresponding Schedule 1 Part
4. information to be reported:
   • general information required to be reported and manner of reporting
   • information to be reported on the facility, including name, identification codes, contacts and pollution prevention activities
   • Parts 1-5 provide information to be reported for substances listed in the corresponding Schedule 1 Part

3.4 Key concepts for understanding NPRI reporting requirements

This section is designed to help facility owners and operators understand the NPRI reporting requirements and determine if they are required to report to the NPRI. The following sections give a brief overview of the NPRI reporting requirements, the substance list, the employee threshold, and other key definitions. Additional definitions for terms used in this guide can be found in the Glossary.

3.4.1 Facilities to which the NPRI reporting requirements apply

In general, an NPRI report is required for any facility:

• where employees work a total of ≥ 20,000 hours (the employee threshold) (see section 3.4.3)
• where specified activities to which the employee threshold does not apply take place (see section 3.4.3)
• where the reporting criteria for CACs are met, whether or not the employee threshold is met
• that is a pipeline installation (defined in section 3.4.2)
• that is subject to the Chromium Electroplating, Chromium Anodizing and Reverse Etching Regulations

In addition, the facility must meet any of the other reporting criteria (e.g., mass, concentration or activity thresholds) for substances on the NPRI substance list.

3.4.2 Definition of facility

The term “facility” refers to a contiguous facility, a portable facility, a pipeline installation or an offshore installation, as defined below. The different types of facilities have to consider different subsets of the NPRI substance list: contiguous facilities and offshore installations need to consider the substances in all Parts of the substance list; portable facilities need to consider substances in Parts 2-5; and pipeline facilities need to consider only Part 4 and 5 substances. See section 3.4.4 for more information on the Parts of the NPRI Substance list.

3.4.3 The employee threshold

Facilities where the employees work a total of 20,000 hours or more during the calendar year (the employee threshold) are required to report to the NPRI, if the thresholds for at least one substance are met, or if an activity-based threshold is met. The employee threshold depends on the number of hours worked by all employees at the facility during the calendar year. This includes:

• all hours worked by individuals employed at the facility, regardless of function or location, including students, part-time and term employees
• all hours worked by the owner(s) who performed work on-site at the facility
• all hours worked by a person, such as a contractor, who performed work at the facility that is related to the operations of the facility
• all paid overtime, vacation and sick leave

The employee threshold must be met by most facilities before they need to consider reporting for Parts 1 through 3 substances, unless activities to which the employee threshold does not apply take place at the facility.

Activities to which the employee threshold does not apply

If one or more of the following activities take place at the facility and other reporting criteria such as mass and concentration thresholds are met, the owner/operator of the facility must report to the NPRI regardless of the number of hours worked by employees:

• non-hazardous solid waste incineration of ≥ 26 tonnes of waste, including, but not limited to, conical burners and beehive burners
• biomedical or hospital waste incineration of ≥ 26 tonnes of waste
• hazardous waste incineration
• sewage sludge incineration
• wood preservation (using heat or pressure treatment, or both)
• terminal operations
• discharge of treated or untreated wastewater from a wastewater collection system discharging an average of ≥ 10,000 m³/day into surface waters
• production of ≥ 500,000 tonnes at pits or quarries

The employee threshold does not apply to facilities where these activities occur because these activities release significant quantities of NPRI substances to the environment, while not necessarily employing enough people to meet the threshold. Detailed descriptions of these activities are provided in the Glossary.

Facilities that are subject to the Chromium Electroplating, Chromium Anodizing and Reverse Etching Regulations are required to report releases, disposals, and transfers for recycling of hexavalent chromium (and its compounds), regardless of the number of employees and regardless of the 50 kg NPRI threshold.

3.4.4 The NPRI substance list: Parts 1-5

The NPRI substance list is divided into five parts, based on specific reporting criteria for each part. The reporting thresholds may be based on mass, concentration, or specific activities and are explained in detail in sections 5 through 9 of this guide. Table 1 provides an overview of the reporting requirements for each Part of the substance list. 

Definitions for the manufacture, process, or otherwise use of a substance are found in the Glossary and are further explained in section 5 of this guide.

3.4.5 Releases, disposals and transfers

Once it has been determined that a facility meets the specific thresholds for an NPRI substance, the total quantities released, disposed of, or transferred must be reported. 

The NPRI has four main categories reportable to the NPRI. Detailed definitions for each of the reportable categories can be found in the Glossary.

3.5 Exemptions from and exclusions to NPRI reporting requirements

3.5.1 Facilities exempt from all reporting requirements

NPRI reporting requirements do not apply if the only activities that take place at a facility are:

• exploration for oil or gas, or the drilling of oil or gas wells
• discharge of treated or untreated wastewater from a wastewater collection system with an average discharge of < 10,000 m³ per day into surface waters
• production of < 500,000 tonnes at pits or quarries
• open-pit mines are not included in the definition of a pit or quarry (see the Glossary) and are subject to NPRI reporting requirements

3.5.2 Exclusions for all substances

The quantity of a substance contained in any of the following items should not be included when calculating if the reporting threshold was met and when calculating and reporting releases, disposals or transfers for recycling:

• Articles that are processed or otherwise used
  • an article is defined as a manufactured item that does not release an NPRI substance when it undergoes processing or other use (see the Glossary for examples)
• materials used as structural components of the facility (buildings and other fixed structures), but not process equipment
• materials used in janitorial or facility grounds maintenance 
  • this includes:
    • NPRI substances contained in fertilizers and pesticides used for grounds maintenance
    • cleaning agents used for maintaining facility cleanliness
    • paint used for building maintenance. 
  • the maintenance of process equipment (e.g., painting or cleaning manufacturing equipment with a solvent) is not excluded
• materials used for personal use by employees or other persons
• intake water or intake air such as:
  • water used for process cooling
  • air used either as compressed air or for combustion

The quantity of a substance that is manufactured, processed or otherwise used in the exploration for oil or gas or in the drilling of oil or gas wells should not be included when calculating if the reporting threshold was met and when calculating and reporting releases, disposals or transfers for recycling. This exclusion applies to all activities from initial exploration until the well is put into production.

In addition, vehicle emissions (not including unpaved road dust) should not be considered when calculating if the thresholds were met and when reporting releases, disposals or transfers for recycling. A vehicle is any mobile equipment that is capable of self-propulsion, including fleet vehicles and earth moving equipment (e.g., loaders, dump trucks, forklifts, excavators and bulldozers).

3.5.3 Activities exempt from reporting for Parts 1-3 substances

The threshold calculation for a substance must exclude the quantity of a substance that is manufactured, processed or otherwise used in the following activities:

• education or training of students (for example, universities, colleges and schools), except when considering whether the threshold is met for reporting releases of ethylene oxide (CAS RN 75-21-8)
• research or development
• maintenance and repair of vehicles (automobiles, trucks, locomotives, rail cars, ships or aircraft), except painting and stripping of vehicles or their components, or the rebuilding or remanufacturing of vehicle components
  • substances used for routine, scheduled and preventative maintenance of vehicles are exempt (e.g., repair, cleaning, replacement of lubricants/fluids)
  • substances used in the painting or stripping of vehicles or vehicle components are subject to reporting
  • there is no exemption for activities that involve the removal, breakdown and total reconstruction of vehicle components (e.g., engines, landing gear, traction motors) using recovered or new parts, such that the rebuilt component is reinstalled or sold as an as-new replacement
• distribution, storage or retail sale of fuels, except as part of terminal operations (defined in the Glossary)
  • the exemption for distribution, storage or sale of fuels does not include terminal operations
• wholesale or retail sale of the substance or articles or products that contain the substance. 
  • materials or substances sent back to a manufacturer, supplier or recycler for reprocessing, repackaging, resale or for credit or payment are considered to be recycled, and the exemption for wholesale or retail sale does not apply
• growing, harvesting or management of renewable natural resources
• the practice of dentistry

A facility is exempt from reporting Parts 1 through 3 substances if the only source or use of that substance is from one or more of the activities listed above. Note, however, that these facilities are not exempt from reporting releases of Parts 4 and 5 substances from stationary combustion equipment. 

In cases where a facility met the reporting criteria for a substance based on sources other than those listed above, the quantity of that specific substance from any exempt activities should also be excluded when reporting releases, disposals or transfers for recycling to the NPRI. As of the 2025 reporting year, the exemption for the quantity of a substance that is manufactured, processed, or otherwise used in the education or training of students no longer applies when reporting releases of ethylene oxide (CAS RN 75-21-8).

3.5.4 Exclusions for tailings and waste rock

The following sections describe the exclusions for unconsolidated overburden, inert waste rock and stable/inert constituents of tailings. Refer to the Glossary for definitions of tailings and waste rock. These exclusions apply only to substances contained in tailings and waste rock. If a substance is released to air or water from tailings or waste rock (e.g., in airborne dust or as effluent), the quantity of the substance released must be included in threshold calculations.

Unconsolidated overburden

Substances contained in unconsolidated overburden should be excluded from threshold calculations and reporting. Unconsolidated overburden is unconsolidated materials overlying the ore or bitumen deposit, including, but not limited to, soil, glacial deposits, sand and sediment.

Inert waste rock

Substances contained in inert or clean waste rock should be excluded from threshold calculations and reporting. Inert waste rock is defined as waste rock either:

• is inert or clean according to a federal or provincial operating permit
• has a sulphur concentration of ≤ 0.2%
• has a sulphur concentration of > 0.2%, and the ratio of neutralizing potential to acid generating potential is ≥ 3:1

There is one exception to the exclusion for inert or clean waste rock: even if waste rock is inert or clean as defined above, the quantity of arsenic in waste rock cannot be excluded if the concentration of arsenic is > 12 milligrams per kilogram of waste rock.

Stable/inert constituents of tailings

Substances contained in certain materials in tailings should be excluded from threshold calculations and reporting (e.g., sand grains from bitumen mines or in-situ production of bitumen). In order to be excluded, these materials must:

• be inert
• be inorganic
• not have been crushed or otherwise physically or chemically altered

The exclusion applies only to the components of tailings that meet the above three criteria (i.e., if part of the tailings stream met the criteria, only that portion of the tailings would be excluded, and the remainder of the tailings would be included).

3.6 Methods for estimating quantities of NPRI substances

3.6.1 Reasonable access to information

Information on releases, disposals and transfers for recycling needs to be reported if the owner/operator possesses the information or may reasonably be expected to have access to the information. The Notice specifies that if emissions are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI. However, all releases, disposals or transfers off site for recycling must be included in threshold calculations and reported, unless otherwise specified, not just those that are measured or monitored.

An NPRI report is mandatory for any substances that meet the reporting thresholds, regardless of whether the substance is being measured or monitored for other jurisdictions. If emissions are not monitored or measured under provincial or federal legislation or a municipal bylaw, reasonable efforts must still be undertaken to gather information on releases, disposals and transfers of a substance. What is “reasonable” depends on individual circumstances, but may include additional measures (e.g., additional monitoring, contacting suppliers, conducting source testing) for NPRI substances.

Other measures that may assist a facility in reporting to the NPRI include:

• requesting detailed composition data from suppliers
  • while some manufacturers may cite proprietary restrictions, others may be able to provide the information when regulatory obligations are cited
• using publicly available data sources such as peer-reviewed literature, information from the United States Environmental Protection Agency, or industry-specific studies to make estimates
• applying surrogate or comparable data where appropriate
  • reasonable estimates based on similar facilities, analogous processes, or comparable substances may be used when specific data is not accessible
• applying expert judgement in the absence of specific data, drawing on knowledge of the chemical and physical processes, the design and operation of the equipment or system, and relevant physical and chemical principles

In deciding whether additional efforts should be undertaken to generate new information for the purposes of NPRI reporting, the following factors, among others, should be considered:

• the health and environmental risks posed by a substance, including whether the substance has been declared toxic under CEPA
• the relative contribution of the industrial sector or the facility to releases, disposals and transfers for recycling of a substance in Canada
• the cost of additional monitoring

3.6.2 Bases of estimate that can be used to report to NPRI

Estimates of the quantity of a substance that is manufactured, processed or otherwise used, and of the quantity that is released, disposed of or transferred for recycling, may be based on one of the following methods:

• continuous emission monitoring systems (reporting system code M1)
• predictive emission monitoring (M2)
• source testing (M3)
• remote quantification (RQ)
• mass balance (C)
• site-specific emission factor (E1)
• published emission factor (E2)
• speciation profile (SP)
• engineering estimates (O)

The reporting system only allows one basis of estimate for each individual type of release, disposal and transfer. If more than one basis of estimate is used to arrive at a single quantity to be reported, select the basis of estimate that was used to calculate the majority of the value. Further explanation on the basis of estimate used can be provided in the comment fields found on the main pages for reporting releases, disposals and recycling in the online reporting system.

A description of these methods is provided in the following sections. Examples using these estimation methods can be found in Appendix B.

Note that facilities can choose the most appropriate basis of estimate to report to the NPRI based on their particular circumstances. However, if the facility is required by federal or provincial legislation or a municipal by-law to measure or monitor releases, disposals or transfers for recycling, the facility must use those data to report to the NPRI.

3.6.3 Method detection limit and use of non-detect values 

In NPRI reporting, the issue of measurements below the method detection limit (MDL) arises in several situations. The MDL is the smallest concentration of the substance under analysis (i.e., the analyte) that produces an instrumental response different from background levels, for a given test method and that meets all analyte detection and identification criteria of the specified test method. An indication that a reportable substance is below the MDL is not equivalent to stating that the substance is not present. If there is reason to believe that the substance is present based on input materials and processes, a value of half the MDL should be used to estimate the release.

In a year where multiple measurements of the concentration of a substance in a given process stream are all below the MDL, and there is no other reason to believe that the substance is present, it can be assumed that the concentration of the substance in that process stream is zero. 

In a year where multiple measurements are taken, and some measurements indicate that the concentration is above the MDL and some indicate that it is below the MDL, there is reason to assume that the substance is present.  Therefore, the mean value of all detectable and non-detectable measurements is recommended to be used.

3.6.4 Other guidance documents and tools

Environment and Climate Change Canada, the U.S. Environmental Protection Agency (US EPA), and industry associations provide resources to complete threshold calculations and to estimate releases, disposals and transfers for recycling of NPRI substances. These resources can be accessed through the NPRI Toolbox. Useful information can also be found in Safety Data Sheets, and in permits and certificates of approval.

The NPRI Toolbox includes a number of tools:

• general guidance
• emission calculation references
• information on fuel combustion and fugitive emission sources
• sector-specific resources
• substance-specific guidance
• additional guidance and resources

4. Information to be reported

4.1 Facility information

4.1.1 General facility information

Below summarizes the general information that must be provided for all facilities that report to the NPRI. Other facility information may also be required, depending on the type of facility and the substances reported.

Facility name and location

• name of the facility
• address of the physical location of the facility such as:
  • a civic address
  • a legal land description
  • a description if no other type of physical address is applicable [e.g., for an offshore installation])
  • latitude and longitude coordinates of the facility if the facility is reporting for the first time or if the facility is portable

Employees

Number of full-time employee equivalents, obtained by dividing by 2,000 hours the sum of:

1. the total hours worked by individuals employed at the facility and the total hours of paid vacation and of sick leave taken by individuals employed at the facility
2. the hours worked on-site at the facility by the owner of the facility, if not employed by the facility
3. the hours worked on-site at the facility by a person, such as a contractor, who, at the facility, performs work related to the operations of the facility

Organization (company)

• legal and trade name of the facility’s company
• mailing address
• Dun & Bradstreet (D-U-N-S) number^{Footnote 1} 
• federal business number^{Footnote 2} 

Parent Companies (if any)

The parent company is the highest level company or group of companies that owns or directly controls the reporting facility. The parent companies of interest to NPRI are those Canadian companies that have greater than 10% ownership in the company.

• legal names of any Canadian parent companies and their percentage of ownership
• civic addresses of the parent companies
• D-U-N-S numbers of the parent companies^{Footnote 1} 
• federal business numbers of the parent companies^{Footnote 2} 

North American Industry Classification System (NAICS) Canada 2022 code

NAICS is an industry classification system developed by the statistical agencies of Canada, Mexico and the United States. Report the primary six-digit NAICS Canada code of the facility and the secondary and tertiary codes, if applicable.

4.1.2 Identification numbers

Environment and Climate Change Canada identification numbers

The NPRI identification number is a unique identifier provided by Environment and Climate Change Canada that must be used when reporting to the NPRI. 

Where applicable, the Greenhouse Gas Reporting Program identification number must also be reported.

Provincial identification numbers for oil and gas facilities

Facilities classified as NAICS 211110 [Oil and gas extraction (except oil sands)] must report all provincial license or identification numbers (e.g., Petrinex numbers) associated with their NPRI identification number.

Petrinex is a joint strategic organization supporting Canada’s upstream, midstream and downstream petroleum industry and is currently represented by the Alberta Department of Energy (DOE), the Alberta Energy Regulator (AER) and the Saskatchewan Ministry of the Economy (ECON), and industry [represented by the Canadian Association of Petroleum Producers (CAPP) and The Explorers and Producers Association of Canada (EPAC)]. The Petrinex identification number is four letters followed by seven numbers.

If a facility in NAICS 211110 does not have a Petrinex ID number, a provincial facility licence number or other provincial or territorial identification number must be reported.

Other provincial or territorial identification numbers

Facilities are required to indicate any relevant provincial or territorial facility identification numbers (or “identifiers”), such as permit numbers. The requirement is limited to identifiers that are issued by the province or territory, with the exception of facilities in Metro Vancouver, where British Columbia has delegated responsibility for issuing operating permits to the Metro Vancouver Regional District. Required identifiers are those that apply at the facility level, as opposed to identifiers for specific equipment.

There are two broad categories of unique facility identifiers that may need to be reported: 

1. identifiers that relate to operating conditions/restrictions on environmental releases from the facility
   • typically the “operating permit” of the facility, which can also be referred to as the approval, authorization, license or certificate
   • these can also be unique identifiers that relate to operating conditions/restrictions outside of the “operating permits,” such as identifiers issued under specific Regulations, Codes of Practice or other non “operating permit” restrictions
2. identifiers that relate to the reporting of environmental data
   •  for example, identifiers issued by provincial air emissions inventories of criteria air contaminants or greenhouse gases

Facilities can opt to report additional identifiers that do not fall within the first two categories, if those identifiers can provide added context to reported releases, disposals and recycling.

Applicable identification numbers will vary depending on the province or territory. Identifiers are generally 4 to 12 alphanumeric characters and may contain special characters (e.g., “-” or “/”). Identifiers can change over time for a wide range of reasons, e.g., renewal, amendment or change of ownership. Updated numbers should be reported.

Specific provincial/territorial programs/initiatives could have more than one facility identifier for each unique NPRI facility or there may be more than one NPRI facility associated with one unique facility identifier under a specific provincial/territorial program/initiative. All unique facilities identifiers must be reported, even if the NPRI-defined facility is only part of a facility as defined by the permitting agency.

The list below provides some information on provincial programs which may apply to the facility and on which identification numbers should be reported to the NPRI. It does not list all possible programs that could apply; it only presents the most common. Facilities should also consider other identification numbers that may need to be reported.

The information provided below is based on responses by the provinces to a survey conducted in late 2020. For the most up-to-date information, please refer to provincial/territorial web pages or contact your provincial/territorial government departments.

British Columbia

• Environmental Management Act waste discharge or air discharge permit, approval, operational certificate, regulation or code of practice
  • Identifiers are numeric
• Metro Vancouver Regional District (MVRD) permit or approval 
  • MVRD identifiers are a mix of numbers and letters
  • a permit identifier is “GVA” followed by unique four-digit number (e.g., GVA0001)
  • an approval identifier is “GVU” followed by unique four-digit number (e.g., GVU0001)

Alberta

• Environmental Protection and Enhancement Act (EPEA) approval and EPEA Code of Practice 
  • EPEA approval and Code of Practice registration numbers are whole numeric values (with values ranging from 1 to approximately 424245)
  • these ID numbers can range from one to six digits, but could potentially be more than six digits in the future
  • this applies to facilities that report air releases of Part 4 substances or hydrogen sulphide to the NPRI
• Alberta Energy Regulator (AER) 
  • AER facility identifiers are alphanumeric (e.g., ABOS00555555) and only apply to facilities in NAICS 21, 22, and 32
  • this may also be known as the Petrinex facility identifier.

Saskatchewan

• The Environmental Management and Protection Act and the Environmental Management and Protection (General) Regulations
  • Identifiers are alphanumeric (e.g., Approval to Operate Pollutant Control Facilities PO20-132 would be the 132nd approval issued in the year 2020; Permit to Construct Industrial Waste Works PC19-034 would be the 34th permit to construct issued in 2019)
• The Mineral Industry Environmental Protection Regulations
  • for sites that are subject to the Industrial Source Air Quality (ISAQ) chapter of the Saskatchewan Environmental Code, an Environmental Protection Permit (EPP) is issued with a 9-digit number identifying the submission of the application (e.g., 10022731)
• Hazardous Materials and Impacted Sites (HMIS)
  • HMIS approval/permit identifiers are the year, followed by the district, followed by the next in sequence (e.g., 20-15-00001 would be 20 for the year 2020, 15 for the 15th district, and 0001 for the 1st in the sequence)

Manitoba

• Environment Act
  • an Environment Act Licence has a 4-digit number that is issued under the Environment Act (e.g., 1234)
  • when a licence is revised, it gets a suffix of letter “R” (e.g., 1234 R)
    • the letter “R” is added every time a licence is revised (e.g., “RR”, “RRR”, etc.)
    • with many changes it is shortened as “6R” or “7R”
  • In the event a licence is altered due to an appeal, then the suffix will be a letter “E” (e.g., 1234 E)
• Dangerous Goods Handling and Transportation Act 
  • Dangerous Goods Handling and Transportation Act licence issued under The Dangerous Goods Handling and Transportation Act is a 3-digit number followed by “HW” (e.g., 123 HW)
  •  If a licence is revised it follows the same procedure as in the Environment Act licence
• Hazardous Waste Regulation 
  • Hazardous waste generator registration issued as per the Hazardous Waste Regulation
  • this has two registration numbers - one for generators and the other for receivers
  • It has five digit numbers prefixed with three letters and written as follows:
    • Consignor (Generator) Registration No.: MBG12345
    • Consignee (Receiver) Registration No.: MBR12345
• Water and Wastewater Facility Operators Regulation
  • Water and Wastewater Facility Operators Regulation certification numbers are numeric (e.g., 2006-123)

Ontario

• Environmental Protection Act environmental compliance approval
  • environmental compliance identifiers are four numeric characters followed by 6 alphanumeric digits (e.g., 9473-953Q2Q)
  • older identifiers can be a string of numbers separated by dashes, or a series of numbers following a letter (e.g., 1-234-56-789, A123456 or W123456)
• Environmental Activity and Sector Registry (EASR)
  • EASR numbers are one letter followed by 14 digits and contain dashes (e.g., R-001-0000000001)

Quebec

• Loi sur la qualité de l’environnement autorisation environnementale
  • 9-digit number
• Québec Air Emissions Inventory (IQEA) under the Regulation Respecting the Mandatory Declaration of Certain Emissions of Contaminants into the Atmosphere (RDOCECA)
  • IQEA facility identification numbers can be 8 numbers or an “X” or “Y” followed by 7 digits

New Brunswick

• New Brunswick Air Quality Regulation approval and New Brunswick Water Quality Regulation approval
  • identifiers are alphanumeric (e.g., I-12345, S-1234)

Nova Scotia

• Nova Scotia Environment Act industrial, municipal, on-site sewage disposal or water approval
  • approval identifiers are 10 to 11 digits, with the first four digits being the year in which the permit was issued with another 6 to 7 following the year (e.g., 2015-092352)
  • some identifiers may have an additional 3 alphanumeric characters at the end, preceded by a “-“ (e.g., 2006-052877-T01, 2004-039856-R01)

Prince Edward Island

• Air Quality Regulations approval
  • approval numbers can be numeric or alphanumeric (e.g., INC20455)
• Sewage Disposal Systems Regulations approval
  • approval numbers can be numeric or alphanumeric (e.g., INC20455)
• Boiler and Pressure Vessels Act Regulations licence number
  • license numbers are up to 6 alphanumeric characters (e.g., PL-C-195 or PL-089)
• Power Engineering Act Regulations license number
  • license numbers are up to 6 alphanumeric characters (e.g., PL-C-195 or PL-089)

Newfoundland and Labrador

• Newfoundland and Labrador Environmental Protection Act Certificates of Approval for the Construction and/or Operation of industrial approvals
  • the identifier is in the form “AAYY-MMXXXXO” where:
    • “AA” is AA
    • “YY” is the 2 digit year
    •  “MM” is the 2-digit month
    • “XXXX” is the 4 digit sequential counter
    • “O” is the optional for revisions
  •  e.g. AA18-085652A is the permit dated August 2018, it is sequentially number 5652, and is the first revision (A)

Yukon 

• Air emissions permit
  • 9-digit number with 2 hyphens (e.g., 4201-60-010, 4201-60-0023, 4201-60-030)

Northwest Territories

• Northwest Territories land use permit
  • 11 alphanumeric characters with no special characters. (e.g., MV2012C0025, MV2019X0008, MV2019X0027)

Nunavut

• Nunavut land use permit
  • 10 alphanumeric characters with no special characters (e.g., N2005X0013, N2012C0026, N2018X0011)

4.1.3 Geographic Information

When reporting geographic information for a facility, it is important to provide the address and geographical coordinates for the physical facility, and not that of the head office of the company. If access to geographic coordinates is not immediately available, searching for a facility through free mapping services available online can provide a reporter with the specific coordinate information.

4.2 Contact information

For each of the following, the name, position, telephone number and email address must be provided:

• technical contact: 
  • the person who prepared the report and who will be able to answer any questions pertaining to its contents
  • a technical contact must be identified
  • all correspondence from Environment and Climate Change Canada regarding the NPRI will be sent to the technical contact if no coordinator (see below) is identified
• public contact: 
  • the person responsible for answering any questions from the public concerning the report
  • this name will appear on the NPRI website as the contact for the facility
  • a public contact must be identified
• coordinator (if any): 
  • the person who is responsible for preparing and submitting NPRI reports for more than one facility for the same company
  • the coordinator is responsible for answering any questions concerning all of the NPRI reports they filed
  • all NPRI correspondence from Environment and Climate Change Canada will be sent to the coordinator, if one is identified
• certifying official: 
  • the person who is legally responsible for the contents of the NPRI report
  • the certifying official is usually the owner or operator, or a company official authorized to act on their behalf
  • a certifying official must be identified
• independent contractor (if any): 
  • if an independent contractor prepared the report, contact information must be provided, including the name of the contracting company

It is important that contact and ownership information be kept up-to-date using the online reporting system or by contacting Environment and Climate Change Canada, if:

• there is a change in the name, telephone number or email address of the contacts identified for the facility
• there is a change in the owner or operator of a facility

4.3 Substance-specific information

Quantities of NPRI substances that are released, disposed of or transferred for recycling that must be reported are described in sections 5-9 of this Guide. The following sections summarize additional information that must be reported.

4.3.1 Information to be reported for Parts 1-3 substances

Nature of the manufacturing, processing or other use of the substance

Facilities are required to indicate whether a substance was manufactured, processed, or otherwise used, by selecting the nature of such activities from a pick-list in the reporting system:

• manufacture:
  • for on-site use/processing
  • for sale/distribution
  • as a by-product
  • as an impurity
• process:
  • as a reactant
  • as a formulation component
  • as an article component
  • repackaging only
  • as a by-product
• otherwise use:
  • as a physical or chemical processing aid
  • as a manufacturing aid
  • ancillary/other use
  • as a by-product
  • any other releases or disposals of the substance

Reasons why the substance is disposed of or recycled

Facilities are required to indicate why a substance is disposed of or transferred off-site for recycling by selecting from a pick-list in the reporting system:

• production residues
• off-specification products
• expiration date passed
• contaminated materials
• unusable parts or discards
• pollution abatement residues
• machine or finishing residues
• site remediation
• other

Name and location of receiving water bodies

Facilities are required to provide the name and province or territory of any surface water bodies into which NPRI substances are released by direct discharge, spills or leaks. Reporting facilities can select the name of the water body from a list in the online reporting system. 

Name and location of receiving off-site facilities

Where NPRI substances are transferred off-site for disposal, treatment prior to final disposal or recycling, facilities are required to provide the name and location of the receiving off-site facilities. Reporting facilities can select the name of the receiving off-site facility from a list in the online reporting system or create a new entry in the system, if the off-site isn’t listed. 

Substance concentration data

The average concentration and method detection limit (MDL) in parts per million (ppm) related to the following must be reported:

• a direct discharge to surface waters, based on source testing or direct monitoring
• the disposal or removal of a substance to tailings management areas
• the disposal or removal of a substance in waste rock

The average annual concentration and method detection limit (MDL) in parts per million (ppm) must be reported. Depending on how the concentration measurement was taken, the units can be converted from a percentage (%), mg/kg (for solids) or mg/L (for liquids) into ppm as follows:

0.0001% = 1 ppm

1.0% = 10,000 ppm

1 mg/kg = 1 ppm

1 mg/L = 1 ppm

The MDL of the method used to determine the average annual concentration and the situation upon which the average concentration is based must also be reported. A number of scenarios are possible with multiple measurements of the concentration of a substance in a given process stream:

• all samples are above the detection limit:
  • the average concentration is based on the measured concentrations of the substance
• half or more than half of samples above detection limit:
  • the average concentration is based on the measured values and half of the MDL for each measurement that is below the MDL
• less than half of samples above detection limit:
  •  the average concentration is based on the measured values and half of the MDL for each measurement that is below the MDL
• no samples above detection limit:
  • if there is no reason to believe that the substance is present, the concentration of the substance in that process can be assumed to be zero
• no sampling:
  • other information is used to estimate (this applies to tailings and waste rock reporting)
• no information available on concentration

An indication of whether the reported quantity (release to water or disposal of tailings or waste rock) was estimated using half the MDL is also required. In addition, if more than one MDL applies, this must also be indicated. In the case of multiple MDLs, additional information can be provided in the comment field.

4.3.2 Information to be reported for all substances

Reasons for changes in reported quantities compared to the previous year

Facilities are required to compare their reported quantities in the current year to the previous year and provide the reason(s) for changes in reported quantities from a pick-list in the reporting system:

• increase in production levels
• decrease in production levels
• changes in estimation methods, including changes in emission factors
  • specify in comment field the previous estimation method, the current estimation method, and the reason for changing the method
• pollution prevention activities (provide details in the Pollution prevention section of this report)
• changes in quantity and/or composition of combusted materials or fuels
• changes in process and/or raw/produced/processed materials
• changes in composition of materials released/disposed of/transferred
• nature of activities results in annual variation in releases/disposals/transfers
  • describe the activity and how it impacts the reported quantity in the comments field
• Activities/events of a non-annual nature
  • e.g. a spill, tailings pond breach, or fire
  • describe the activity/events in the comments field
• other (specify in comment field)
• no significant change (i.e. <10% or no change)
• not applicable (first year reporting this substance)

Monthly and quarterly breakdown of releases

For Parts 1-3 substances, facilities are required to report a percentage breakdown by quarter. For Parts 4-5 substances, facilities are required to report a percentage breakdown by month. In both cases, percentages must add up to 100%.

4.4 Additional information for electricity generating units

Facilities in all North American Industry Classification System (NAICS) codes that report releases of mercury or criteria air contaminants to air must assign those releases to each electricity generating unit that meets the following criteria:

1. the unit has a nameplate capacity of 25 MW or more
2. the unit distributes or sells to the grid 33% or more of its potential electrical output

An electricity generation unit means physically connected equipment that operates together to produce electricity for sale or distribution to the grid by means of thermal energy produced by the combustion of fossil fuels and is stationary when used, and is not in or on a machine that is self-propelled. 

Potential electrical output means the quantity of electricity that would be generated by a unit in a calendar year if the unit were to operate at capacity at all times during that calendar year.

The 33% threshold must be assessed on an annual basis. If a unit meets the 33% threshold in a calendar year, but does not meet it in the subsequent year, reporting at the unit level for that unit is still required. This requirement applies for three years. For example, if a unit met the 33% threshold only in 2024, emissions from the unit must be reported separately for 2024, 2025 and 2026 reports, but not from 2027 onwards (unless it were to meet the threshold again in a future year).

Facilities that meet the threshold requirements for unit-level reporting must also provide details about the unit, including:

• unit gross generating capacity
• commissioning year
• technology or fuel type
• whether the unit includes emissions from duct firing or other secondary combustion sources
• air pollutant controls installed and operating on the unit

4.5 Pollution prevention activities

Facilities are required to report:

• whether and why a pollution prevention (P2) plan was prepared in that reporting year
• the name of the P2 notice, jurisdiction, or program for which the P2 plan is required
• information on P2 activities undertaken during the year
• the substances for which the P2 activities were undertaken

Environment and Climate Change Canada analyzes P2 information and publishes a summary of the P2 information submitted by facilities in Pollution Prevention in Practice. The published information is updated on an annual basis.

4.6 Comments

Comment fields are provided on many screens in the online reporting system. Comments can be used to provide additional information, such as details about a facility’s operations, how a substance is used, details of pollution prevention activities, reasons for changes in quantities reported from the previous year, or the methods used to calculate reported quantities.

The information provided in comment fields can help users understand the context around the reported information. Clear and concise comments contribute to the understandability and completeness of the NPRI data set. Explanations of changes or anomalies in submitted data help to prevent unnecessary contact with facilities during the quality control process.

4.7 Other requirements

4.7.1 Electronic statement of certification

A statement of certification must be electronically signed and submitted with the NPRI report using the online reporting system. The certifying official should verify that the information submitted is true, complete and accurate, and acknowledge that the data will be made public. The certifying official is legally responsible for the contents of the NPRI report.

4.7.2 Record keeping

Pursuant to subsection 46(8) of CEPA, the owner/operator of a facility is required to retain copies of all information on which their report is based, including any calculations, measurements and other related data, for three years from the applicable reporting deadline. This information must be kept at the facility or at the principal place of business in Canada of the owner/operator of the facility to which the information relates, for three years.

4.7.3 Other reports

There are several other types of NPRI reports that can be filed using the online reporting system:

• Does Not Meet Criteria (DNMC) report: 
  • a facility that submitted a report for the previous year, but no longer meets NPRI reporting criteria for the current year, is required to submit a “Does Not Meet Criteria” report by the reporting deadline
• Sale/Close/Purchase report: 
  • submit a “sale/close/purchase” report when transfers of ownership occur, or if a facility closes during the calendar year
• Update: 
  • an update to current and previous reports can also be submitted using the online reporting system

4.8 Voluntary reporting

The NPRI also accepts voluntary reporting for NPRI substances when a facility does not meet the reporting requirements. Voluntary reports assist the NPRI in providing a more comprehensive description of releases and transfers of pollutants in Canada. A voluntary report for a release, disposal or transfer of a substance should be specified as such by selecting the appropriate option within the online reporting system.

5. Reporting for Part 1 substances

5.1 Requirements for Part 1 substances

Part 1 of the NPRI substance list contains 373 substances or substance groupings that are divided into three categories: Part 1A, Part 1B and Part 1C. Part 1A and Part 1B reporting requirements share many similarities, with the main difference being that substances listed in Part 1B have lower mass and concentration thresholds compared to those in Part 1A. Part 1C contains PFAS that are listed at a lower mass and concentration threshold than substances listed in Part 1A. The following terms apply to Part 1A, Part 1B, and Part 1C substances.

5.1.1 Manufacture, process, or otherwise use

When reporting for substances listed on Part 1, a facility must first consider the quantity of the substance manufactured, processed or otherwise used at the facility. Below is an overview of activities to consider when calculating the quantity of Part 1 substances manufactured, processed, or otherwise used:

• manufacture:
  • for on-site use/processing
  • for sale/distribution 
  • incidentally as a by-product
  • as an impurity
• process:
  • as a reactant 
  • as a formulation component
  • as an article component
  • during repackaging
  • as a by-product 
• otherwise use:
  • as a physical or chemical processing aid
  • as a manufacturing aid
  • for ancillary/other use 
  • as a by-product
  • any other releases or disposals of the substance

5.1.2 By-products

The term “by-product” refers to the quantity of an NPRI Part 1 substance that is incidentally manufactured, processed or otherwise used at the facility at any concentration, and released to the environment or disposed of. The quantity of a substance that is recycled or that remains in the final product is not considered to be a by-product for the purpose of the NPRI threshold calculation.

In general, if a quantity of a substance is intentionally manufactured, processed or otherwise used at a facility, then that quantity of the substance is not a by-product, even if it is unintentionally manufactured, processed or otherwise used at another step in the process.

Overall quantities of by-products can be significant, even though their concentration may be low. Therefore, the quantity of a substance that is a by-product must be included in the calculation of the reporting threshold, regardless of concentration. The by-product requirements only apply to Part 1 substances and are only used for the purpose of determining whether or not the mass threshold for a substance has been met.

Some examples of by-products are:

• hydrogen fluoride is incidentally manufactured and released during aluminum smelting
  • therefore, the hydrogen fluoride is a by-product and must be included in the calculation of the reporting threshold, regardless of concentration
• manganese and nickel are incidentally present in coal
  • during combustion, a portion of these metals is concentrated in the ash, which is disposed of, and a portion of the metals is released in stack emissions
  • the weight of the metal by-products, must be included in the calculation of the reporting threshold, regardless of concentration

An example of when substances are not considered by-products:

• metal cuttings, sent for disposal, contain alloyed chromium and nickel at a concentration of less than 1%
  • the chromium and nickel are essential components of the alloy; therefore, they are not incidentally processed and are not considered to be by-products
  • the chromium and nickel in the metal cuttings do not need to be included in the calculation of the reporting threshold, because the substances are present at a concentration less than the concentration threshold of 1%

5.2 Reporting for Part 1A substances - Core substances

Part 1A lists 177 substances and groups of substances of concern, most of which have been listed on the NPRI since its inception. These substances are commonly referred to as the “core substances,” and comprise the majority of the NPRI substance list.

In general, any person who owns or operates a contiguous facility or offshore installation must submit an NPRI report for a Part 1A substance if both of the following criteria are met:

1. employees work a total of ≥ 20,000 hours, or activities to which the employee threshold does not apply (see section 3.4.3) take place at the facility
2. the total quantity of the Part 1A substance present in the following scenarios is ≥ 10 tonnes:
   • manufactured, processed or otherwise used at a concentration (by weight) of 1% or more
   • incidentally manufactured, processed or otherwise used as a by-product at any concentration
   • contained in tailings disposed of during the calendar year at any concentration
   • contained in waste rock disposed of during the calendar year that is not clean or inert (see section 3.5.4) at a concentration (by weight) of 1% or more

5.2.1 Part 1A substance qualifiers

Some Part 1A substances and groups of substances have additional qualifiers that specify the physical or chemical form, state or particle size of the substance that is to be included. The qualifiers, described below, help to determine whether a report will be required for a given substance.

5.2.2 Calculating the manufacture, process or otherwise use quantity for Part 1A substances

To calculate the amount to compare to the 10-tonne reporting threshold, add up the following quantities of a Part 1A substance:

• quantities that are manufactured, processed or otherwise used at a concentration equal to or greater than 1% by weight
• quantities that are incidentally manufactured, processed or otherwise used (a by-product), at any concentration, and released on-site to the environment or disposed of on- or off-site
• quantities that are contained in tailings disposed of during the calendar year, at any concentration
• quantities that are contained in waste rock that is not inert and that is disposed of during the calendar year at a concentration equal to or greater than 1% by weight

Any release or disposal of an NPRI substance must be included in the otherwise used category. For example, the quantity of the NPRI substance contained in dust released to air from materials stored on site would be included, whether or not the material is used for a specific purpose at the facility. Another example is a spill of an NPRI substance to water or land during storage or handling.

Since a substance may undergo many processes in a facility, care should be taken not to double-count process streams when calculating the reporting threshold. Do not include quantities of substances more than once in manufacture, process or otherwise use calculations. For example, if a substance is processed and released, the release quantity does not need to be added to the process quantity.

Do not include quantities of a Part 1A substance contained in any of the sources that are excluded, as listed in section 3.5.2, or from the activities listed in section 3.5.3.

A quantity of a substance that is transferred off-site for recycling and returned to the facility should be treated as the equivalent of newly purchased material. A quantity of a substance that is recycled on-site and re-introduced to a process stream (e.g., substances in ore processing water that are recycled back into the process from tailings) should be included in the threshold calculation only once.

The total quantity of a Part 1A substance manufactured, processed or otherwise used at concentrations greater than or equal to 1%, at any time or in any part of the facility, must be included when calculating the 10 tonnes reporting threshold. For example, the quantity of a substance received by a facility at 30% concentration and then diluted to less than 1% for use is included in the threshold calculation. A substance received at the facility at less than 1% and subsequently concentrated to 5% would also be included in the threshold calculation. Activities to consider in the manufacture, process or otherwise use of a substance are listed in section 5.1.

Facilities that repackage or transfer Part 1A substances between containers must consider the entire quantity of the substance contained in the original container or in bulk for threshold calculations.

If only a range of concentrations is available for a substance present in a mixture, contact the supplier of the substance for more detailed information. If no additional information is available, use the average of the range for threshold determinations.

5.2.3 Calculating releases, disposals and transfers for recycling of Part 1A substances

If the reporting threshold for a Part 1A substance is met, a subsequent calculation is required to determine the quantities of that substance that are released, disposed of and transferred for recycling. If the reporting threshold is met, all releases, disposals and transfers for recycling of that substance must be reported, regardless of their concentration or quantity and regardless of whether or not the quantity is used in the threshold calculation. The only exceptions to this are quantities of the substance:

• contained in the materials listed in section 3.5.2
• that are manufactured processed or otherwise used in the activities listed in section 3.5.3
• contained in waste rock where the substance is at a concentration of less than 1% (see section 3.5.4)

5.2.4 Reporting releases, disposals and transfers for recycling of Part 1A substances

All releases, disposals and transfers for recycling of Part 1A substances must be reported in tonnes. Note that the quantity manufactured, processed or otherwise used is not reported.

Note that even if on-site releases, disposals or off-site transfers for recycling are zero or below the mass or concentration thresholds, a report must be submitted for a Part 1A substance, once the 10 tonnes reporting threshold has been met.

When total releases of a Part 1A substance are less than one tonne, a facility may choose to report the release as a total without specifying the environmental media (air, water, or land). Facilities are encouraged to report the breakdown by media, if the information is available.

5.3 Reporting for Part 1B substances – Alternate threshold substances

Part 1B substances may have significant environmental and human health impacts at relatively low levels. Because minimal releases of Part 1B substances may result in significant adverse effects, the reporting thresholds for Part 1B substances are lower than those for Part 1A substances. As such, these substances are commonly referred to as the “alternate threshold substances.”

In general, any person who owns or operates a contiguous facility or an offshore installation must submit a report for a Part 1B substance if both of the following criteria are met:

1. employees work a total of ≥ 20,000 hours, or activities to which the employee threshold does not apply (see section 3.4.3) take place at the facility
2. the total quantity of the Part 1B substance present in one or more of the following scenarios is greater than or equal to the mass threshold specified in Table 2:
   • manufactured, processed or otherwise used at or above the concentration specified in Table 2
   • incidentally manufactured, processed or otherwise used as a by-product at any concentration
   • contained in tailings at any concentration
   • contained in waste rock that is not inert and that is disposed of, at any concentration (see section 3.5.4)

In addition, a facility that is subject to the Chromium Electroplating, Chromium Anodizing and Reverse Etching Regulations must report for hexavalent chromium (and its compounds), regardless of the number of employees and regardless of the mass and concentration thresholds listed in Table 2. If the facility does not meet any other NPRI requirements, only a report for releases, disposals, or transfers of hexavalent chromium (and its compounds) is required.

       

5.3.1 Part 1B substance qualifiers

Mercury, cadmium, arsenic, hexavalent chromium, lead, cobalt, selenium and thallium are listed with the qualifier “and its compounds.” The pure element and any compound, alloy or mixture of any Part 1B substance must be reported as the equivalent weight of the metal itself. For example, if potassium dichromate (K₂Cr₂O₇, molecular weight = 294 grams per mole [g/mol]) is used, only the mass contribution of hexavalent chromium (2×52 g/mol) in K₂Cr₂O₇ should be included in the threshold calculation for hexavalent chromium.

Note that lead has an additional qualifier: the lead contribution from tetraethyl lead, stainless steel, brass and bronze alloys should be excluded from threshold calculations for lead. Tetraethyl lead should be treated as a separate substance. If the criteria are met, separate reports should be submitted for lead (and its compounds) and tetraethyl lead, with the reporting criteria applied to each substance separately.

Hydrazine and chlorhexidine are listed with the qualifier “and its salts.” Weak acids and bases are listed with this qualifier. Although the CAS RN that appears on the NPRI list is specific to the acid or base, all salts of these substances must be reported as an equivalent weight of the acid or base.

Toluenediisocyanate is listed with the qualifier “mixed isomers.” The total of all isomers occurring in mixtures must be reported.

Any substance whose molecular formula meets the category definition for medium-chain (C_14-17) or long- chain (C_18-20) chlorinated alkanes must be included when calculating the manufacture, process or otherwise use threshold quantity, and reported if the threshold is exceeded. In addition, chemical mixtures that contain substances that meet the medium-chain (C_14-17) or long-chain   (C_18-20) chlorinated alkane category definition must also be considered. However, for mixtures, NPRI reporting facilities would only include the chlorinated alkane component of the chemical mixture that meets the respective category definition in threshold calculations and reported quantities.

5.3.2 Calculating the manufacture, process or otherwise use quantity for Part 1B substances

To calculate the amount to compare to the reporting threshold, add up the following quantities of a Part 1B substance:

• quantities that are manufactured, processed or otherwise used at a concentration equal to or greater than the concentration threshold (if any) specified in Table 2
• quantities that are incidentally manufactured, processed or otherwise used (a by-product), at any concentration, and released on-site to the environment or disposed of on- or off-site
• quantities that are contained in tailings disposed of during the calendar year, at any concentration
• quantities that are contained in waste rock that is not inert and that is disposed of during the calendar year, at any concentration

Any release or disposal of an NPRI substance must be included in the quantity otherwise used. For example, the quantity of the NPRI substance contained in dust released to air from materials stored on site would be included, whether or not the material is used for a specific purpose at the facility. Another example is a spill of an NPRI substance to water or land during storage or handling.

Since a substance may undergo many processes in a facility, care should be taken not to double-count process streams when calculating the reporting threshold. Do not include quantities of substances more than once in manufacture, process or otherwise use calculations. For example, if a substance is processed and released, the release quantity does not need to be added to the process quantity.

Do not include quantities of a Part 1B substance contained in any of the sources that are excluded, as listed in section 3.5.2, or from the activities listed in section 3.5.3.

As noted previously, quantities of substances disposed of in inert or clean waste rock do not need to be included in threshold calculations. However, the quantity of arsenic contained in inert or clean waste rock can be excluded only if the concentration of arsenic is < 12 mg/kg of waste rock.

5.3.3 Calculating releases, disposals and transfers for recycling of Part 1B substances

If the reporting threshold for a Part 1B substance is met (as discussed in section 5.3.2), a subsequent calculation is required to determine the quantities of that substance that are released, disposed of and transferred for recycling.

If the reporting threshold for a Part 1B substance is met, a subsequent calculation is required to determine the quantities of that substance that are released, disposed of and transferred for recycling. If the reporting threshold is met, all releases, disposals and transfers for recycling of that substance must be reported, regardless of their concentration or quantity and regardless of whether or not the quantity is used in the threshold calculation. The only exceptions to this are quantities of the substance:

• contained in the materials listed in section 3.5.2
• that are manufactured processed or otherwise used in the activities listed in section 3.5.3

5.3.4 Reporting releases, disposals and transfers for recycling of Part 1B substances

All releases, disposals and transfers for recycling of Part 1B substances must be reported in kilograms (kg). Note that the quantity manufactured, processed or otherwise used is not reported.

Any facility that is subject to the Chromium Electroplating, Chromium Anodizing and Reverse Etching Regulations must report releases, disposals, and transfers for recycling of hexavalent chromium (and its compounds), regardless of the number of employees and regardless of the 50 kg mass threshold and 0.1% concentration threshold. If the facility does not meet any other NPRI requirements, only a report for releases, disposals, or transfers of hexavalent chromium (and its compounds) is required.

Note that even if on-site releases, disposals or off-site transfers for recycling are zero or below the mass or concentration thresholds, a report must be submitted for a Part 1B substance once the mass reporting threshold has been met.

5.4 Reporting for Part 1C substances – Per- and polyfluoroalkyl substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of human-made substances. Some typical uses of PFAS include surfactants, lubricants, and repellents (for dirt, water, and grease). PFAS can be found in certain firefighting foams, food packaging, drugs, cosmetics, sunscreens, pesticides, textiles (e.g., carpets, furniture, and clothing), non-stick cookware, vehicles, and electronics. Of the thousands of PFAS, 163 individual PFAS substances are listed on the NPRI (see Table 3), and the reporting thresholds apply to each substance individually.

In general, any person who owns or operates a contiguous facility or an offshore installation must submit a report for a Part 1C substance if both of the following criteria are met:

1. employees work a total of ≥ 20,000 hours, or activities to which the employee threshold does not apply (see section 3.4.3) take place at the facility
2. the total quantity of the Part 1C substance present in one or more of the following scenarios is greater than or equal to 1 kg:
   • manufactured, processed or otherwise used at or above 0.1% concentration;
   • incidentally manufactured, processed or otherwise used as a by-product at any concentration;
   • contained in tailings at any concentration; and
   • contained in waste rock that is not inert and that is disposed of, at any concentration (see section 3.5.4)

Detailed guidance for reporting Part 1C substances can be found in the PFAS Guidance for Reporting to the National Pollutant Release Inventory prepared by Environment and Climate Change Canada.

     

5.4.1 Calculating the manufacture, process or otherwise use quantity for Part 1C substances

Facilities need to determine which products they MPO contain any of the 163 PFAS listed in the NPRI. Sources of information to identify the presence of individual PFAS can involve reviewing the Safety Data Sheet and/or Technical Data Sheet for the products that the facility MPOs that have the potential of containing PFAS. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant information.  

To calculate the amount to compare to the reporting threshold, add up the following quantities of each Part 1C substance:

• quantities that are manufactured, processed or otherwise used at a concentration equal to or greater than 0.1%
• quantities that are incidentally manufactured, processed or otherwise used (a by-product), at any concentration, and released on-site to the environment or disposed of on- or off-site 
• quantities that are contained in tailings disposed of during the calendar year, at any concentration
• quantities that are contained in waste rock that is not inert and that is disposed of during the calendar year, at any concentration

Any release or disposal of an NPRI substance must be included in the quantity otherwise used. For example, the quantity of the NPRI substance contained in dust released to air from materials stored on site would be included, whether or not the material is used for a specific purpose at the facility. Another example is a spill of an NPRI substance to water or land during storage or handling.

Since a substance may undergo many processes in a facility, care should be taken not to double-count process streams when calculating the reporting threshold. Do not include quantities of substances more than once in manufacture, process or otherwise use calculations. For example, if a substance is processed and released, the release quantity does not need to be added to the process quantity. 

Do not include quantities of a Part 1C substance contained in any of the sources that are excluded, as listed in section 3.5.2, or from the activities listed in section 3.5.3.

5.4.2 Calculating releases, disposals and transfers for recycling of Part 1C substances

If the reporting threshold for a Part 1C substance is met (as discussed in section 5.4), a subsequent calculation is required to determine the quantities of that substance that are released, disposed of and transferred for recycling. If the reporting threshold is met, all releases, disposals and transfers for recycling of that substance must be reported, regardless of their concentration or quantity and regardless of whether or not the quantity is used in the threshold calculation. The only exceptions to this are quantities of the substance:

• contained in the materials listed in section 3.5.2
• that are manufactured processed or otherwise used in the activities listed in section 3.5.3

5.4.3 Reporting releases, disposals and transfers for recycling of Part 1C substances

All releases, disposals and transfers for recycling of Part 1C substances must be reported in kilograms (kg). Note that the quantity manufactured, processed or otherwise used is not reported.

Note that even if on-site releases, disposals or off-site transfers for recycling are zero or below the mass or concentration thresholds, a report must be submitted for a Part 1C substance once the mass reporting threshold has been met.

6. Reporting for Part 2 substances – Polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) may be used as commercial chemicals, incidentally manufactured in certain industrial processes and during combustion, or contained in tailings. There are 31 PAHs listed in Part 2 of the NPRI substance list.

6.1 Reporting criteria for Part 2 substances

With the exception of facilities where wood preservation using creosote takes place (see below), reporting for PAHs is based on the quantities of PAHs that are released, disposed of or transferred for recycling as a result of incidental manufacture or from the generation of tailings. A person who owns or operates a contiguous facility, a portable facility, or an offshore installation must submit reports for PAHs if both of the following criteria are met:

1. employees work a total of ≥ 20,000 hours, or activities to which the employee threshold does not apply (listed in section 3.4.3) take place at the facility
2. the sum of all PAHs released, disposed of or transferred off-site for recycling as a result of incidental manufacture and/or as a result of the generation of tailings is ≥ 50 kg

Wood preservation facilities using creosote must report for Part 2 substances, regardless of quantities and regardless of the number of hours worked by employees. See the Guidance for wood preservation facilities reporting to the NPRI for more information. 

6.2 Reporting releases, disposals and transfers for recycling of Part 2 substances

All releases, disposals and transfers for recycling of Part 2 substances must be reported in kilograms.

If the 50 kg threshold is met, or if wood preservation using creosote takes place at the facility, a report must be submitted for PAHs. Releases, disposals and transfers for recycling must be reported for the individual PAHs, even though the 50 kg threshold applies to the aggregate total of all 31 PAHs.

Depending on the information that is available, there are three ways to report PAHs:

• if information on releases, disposals and transfers for recycling for quantities of individual PAHs is available:
  • add quantities of individual PAHs
  • if the total is ≥ 50kg:
    • report quantities of individual PAHs that are released, disposed of or transferred for recycling in quantities ≥ 5 kg
    • quantities of individual PAHs that are < 5 kg are not required to be reported
• if only a combination of information on the quantities of individual and the quantity total PAHs is available:
  • add quantities of total PAHs and any individual PAHs that are not already included in the total unspeciated PAHs
  • if the total is ≥ 50kg:
    • report quantities of individual PAHs that are ≥ 5 kg, and
    • report “total unspeciated PAHs” (not including quantities of individually reported PAHs)
    • quantities of individual PAHs that are < 5 kg are not required to be reported
• if the only available information is for the quantity of total PAHs:
  • if total PAHs are ≥ 50kg report “total unspeciated PAHs”

Note that “total unspeciated PAHs” is not intended to include the quantity of PAHs that are reported individually. In order to avoid double counting when reporting both individual PAHs and “total unspeciated PAHs”, the quantities of individual PAHs that are reported separately should not be included in the quantity reported for “total unspeciated PAHs”. 

In addition, do not include release, disposal and transfer for recycling quantities of PAHs from activities listed in section 3.5.3 when reporting PAHs. Do not include release, disposal and transfer for recycling quantities of naphthalene (PAH listed in Part 1A) when reporting for total PAHs.

Facilities using creosote for wood preservation must report for PAHs regardless of the quantity of PAHs released, disposed of or transferred for recycling or the number of hours worked by employees.

7. Reporting for Part 3 substances – Dioxins, furans and hexachlorobenzene

Polychlorinated dibenzo-p-dioxins (dioxins), polychlorinated dibenzofurans (furans) and hexachlorobenzene are released primarily as by-products of industrial and combustion processes; they are also found as contaminants in certain pesticides or chlorinated solvents. Hexachlorobenzene may also be found as a contaminant in the wood preservative pentachlorophenol (PCP). 

Hexachlorobenzene and 17 dioxin and furan congeners are listed in Part 3. For a list of these congeners, see Table 4.

7.1 Reporting criteria for Part 3 substances

Reporting for dioxins, furans and hexachlorobenzene is mandatory for a contiguous facility, a portable facility or an offshore installation where the activities specified below take place, regardless of quantity or concentration. The employee threshold applies to some of these activities, but does not apply to others, as indicated below. For those activities to which the employee threshold applies, both criteria must be met (i.e., the activity must take place, and the employee threshold must be met). For activities to which the employee threshold does not apply, reporting for dioxins, furans and hexachlorobenzene is mandatory, regardless of the number of hours worked by employees.

The employee threshold does not apply to wood preservation activities in general. However, only wood preservation using PCP triggers mandatory reporting of Part 3 substances. PCP, by its chemical structure, is a close surrogate to hexachlorobenzene. PCP is derived from hexachlorobenzene by substituting one of HCB’s six chloro-substituents with a hydroxyl group. Given its chemical similarity to HCB and that its manufacturing ingredients contain the precursors for dioxin and furan production (i.e., chlorinated aromatics), the manufacture of PCP often results in the incidental manufacture of HCB, dioxins and furans.

Activities for which reports on dioxins, furans and hexachlorobenzene are required:

• activities where the employee threshold does not apply:
  • non-hazardous solid waste incineration of ≥ 26 tonnes of waste
    • including conical burners and beehive burners
  • biomedical or hospital waste incineration of ≥ 26 tonnes of waste
  • hazardous waste incineration
  • sewage sludge incineration
  • wood preservation using pentachlorophenol
• activities where the employee threshold applies:
  • base metals smelting (copper, lead, nickel or zinc only)
  • smelting of secondary aluminum
  • smelting of secondary lead
  • production of iron ore pellets using an induration furnace or manufacturing of sinter using the iron sintering process
  • operation of electric arc furnaces in steel foundries
  • operation of electric arc furnaces in steel manufacturing
  • production of magnesium
  • manufacturing of Portland cement
  • production of chlorinated organic solvents or chlorinated monomers
  • combustion of fossil fuel in a boiler unit, with a nameplate capacity of ≥ 25 megawatts of electricity, for the purpose of producing steam for the production of electricity
  • combustion of hog fuel originating from logs that were transported or stored in salt water in the pulp and paper sector
  • combustion of fuel in kraft liquor boilers used in the pulp and paper sector
  • titanium dioxide pigment production using the chloride process

7.2 Reporting releases, disposals and transfers for recycling of Part 3 substances

Only those quantities of dioxins, furans and hexachlorobenzene that result from the activities listed in section 7.1 need to be reported. Quantities of Part 3 substances that result from other activities do not need to be reported.

The information that needs to be reported for Part 3 substances depends on the method used to determine the quantities released, disposed of and transferred for recycling. There are three possible scenarios:

• quantities are determined using CEMS, PEM or source testing
• quantities are estimated using other methods 
• no information is available

To determine what is required to be reported, the quantities determined using CEMS, PEM or source testing must be compared to the level of quantification (LoQ). LoQ is defined in CEPA as “the lowest concentration that can be accurately measured using sensitive but routine sampling and analytical methods.” The estimated LoQs for dioxins, furans and HCB, determined by Environment and Climate Change Canada for gases, liquids and solids are listed below:

• dioxins and furans^{Footnote 4}  :
  • gases^{Footnote 5}   - 32 picograms (pg) toxicity equivalents (TEQ)/m³
  • solid^{Footnote 6}   - 9 pg TEQ/g
  • liquid^{Footnote 7}   - 20 pg TEQ/L
• hexachlorobenzene:
  • gases^{Footnote 5}    - 6 nanograms (ng)/m³ 
  • solid^{Footnote 6}   - 2 ng/g
  • liquid^{Footnote 7}   - 70 ng/L 

Measured concentrations must be compared to the LoQ for each type of release, disposal and transfer for recycling. If measured quantities are greater than or equal to the LoQ, the quantities must be reported. If measured quantities are less than the LoQ, reporting the quantities is optional.

If quantities of dioxins, furans and HCB are estimated using remote quantification, mass balance, emission factors, a speciation profile or engineering estimates, the quantities that are released, disposed of or transferred for recycling do not need to be compared to an LoQ, and must be reported.

The online reporting system allows up to six decimal places to be reported. If a quantity is being reported, it must be 0.000001 g or more. Below summarizes the information that should be reported for Part 3 substances depending on the method of estimation:

• CEMS, PEM, or source testing:
  • If at or above LoQ report the quantity, and report that the quantity is at or above the LoQ (detail code “AL” in the reporting system)
  • If below LoQ report that the quantity is below the LoQ (detail code “BL”) 
    • the quantity can also be reported, but this is optional when it is below the LoQ (detail code “BQ”)
• remote quantification, mass balance, a site-specific / published emission factor, speciation profile, or an engineering estimate:
  • report the quantity
• no quantity was able to be determined, or no information is available: 
  • report that no information is available under “Basis of Estimate” in the reporting system (detail code “NI”)

7.2.1 Reporting dioxins and furans as individual congeners or toxic equivalents

Depending on the information that is available, there are two ways to report dioxins and furans:

• Information on individual congeners of dioxins and furans must be reported if it is available, in grams
• If the only information available is for total dioxins and furans, the total must be reported in grams of toxic equivalents (TEQ)

Dioxins and furans are often found in complex mixtures, typically at extremely low concentrations, making it difficult to determine the cumulative toxicity of the mixture. Accordingly, toxic equivalency factors (TEFs) have been assigned to each dioxin and furan congener as weighting factors. These TEFs are assigned relative to the toxicity of 2,3,7,8-TCDD, the most toxic congener.

The TEFs listed in Table 4 should be used. To calculate TEQ: multiply the concentration (or quantity) of an individual congener by its respective TEF. For example, 1,2,3,4,7,8-HxCDF has a TEF of 0.1, and a sample concentration of 30 ng/kg 1,2,3,4,7,8-HxCDF is therefore equal to 3 ng TEQ/kg.

Source: Van den Berg, Et al. (2006). The 2005 World Health Organization reevaluation of human and Mammalian toxic equivalency factors for dioxins and dioxin-like compounds. Toxicological Sciences, Volume 93, Issue 2, pp. 223-241. https://doi.org/10.1093/toxsci/kfl055. 

8. Reporting for Part 4 substances – Criteria air contaminants

Air issues, such as smog and acid rain, result from the presence of, and interactions between, a group of pollutants known as criteria air contaminants (CACs) and related pollutants. There are seven CACs listed in Part 4 (see section 8.5). The following sections provide information on what should be included and excluded when reporting releases of CACs.

8.1 Nitrogen oxides

Nitrogen oxides (NO_x) include nitric oxide (NO) and nitrogen dioxide (NO₂). Since NOx is a mixture, both NO and NO₂ must be expressed on an NO₂-equivalent basis before the individual quantities are combined for the total NO_x release. Do not include nitrous oxide (N₂O) when calculating NO_x releases.

8.2 Sulphur dioxide

Sulphur dioxide (SO₂) is part of the sulphur oxide (SO_x) family of gases. However, reporting to the NPRI is only required for SO₂, not SO_x. Therefore, the quantity of the other gases in the SO_x family, (i.e., sulphite, sulphur trioxide [SO₃] and sulphate [SO₄]) released should not be considered when calculating SO₂ releases.

8.3 Particulate matter

Three size fractions of particulate matter (PM) are required to be reported to the NPRI:

• total PM with a diameter less than 100 micrometres (TPM)
• PM with a diameter less than or equal to 10 micrometres (PM₁₀)
• PM with a diameter less than or equal to 2.5 micrometres (PM_2.5)

The TPM fraction includes PM₁₀ and PM_2.5, while PM₁₀ includes PM_2.5. It is therefore impossible for PM_2.5 or PM₁₀ releases to exceed TPM releases. It is also impossible for PM_2.5 releases to exceed PM₁₀ releases. 

Only filterable PM is reportable to the NPRI; condensable PM should not be included in release calculations. If the best available estimation method includes both filterable and condensable PM, and it is not possible to determine how much of the quantity is condensable PM to remove from the total, then the total can be reported. Facilities are required to indicate whether their reported PM quantities include condensable PM and can include a comment in the reporting system to provide more information.

Filterable particulate matter is particles that are directly emitted by a source as a solid or liquid (aerosol) at stack or release conditions and that are captured on the filter of a stack test sampling train. Filterable PM is a component of primary PM.

Condensable particulate matter (CPM) is material that is a vapor at stack conditions, but that condenses and/or reacts upon cooling and dilution in ambient air to form solid or liquid PM immediately after discharge from the stack. CPM is a component of primary PM. All CPM is assumed to be in the PM_2.5 fraction.

TPM, PM₁₀ and PM_2.5 releases from road dust caused by vehicular traffic on unpaved roads within facility boundaries are required to be included in release calculations, when travel on these roads is ≥ 10,000 vehicle kilometres travelled per year, where the air release threshold is also met.

8.4 Volatile organic compounds (total)

Volatile organic compounds (VOCs) are an aggregate grouping of more than 1,000 organic substances that readily volatilize and undergo photochemical reactions in the atmosphere.

VOCs (total) should be reported as the total quantity of VOCs that participate in atmospheric photochemical reactions. Do not include any of the 63 substances or groups of substances that are specified in Schedule 1 of CEPA as being excluded from the VOC definition (Table 5).

VOCs are listed in Parts 1, 2, 4 and 5 of the NPRI. When reporting VOCs, it is important to note the following:

• total organic compounds (TOCs) and VOCs do not have the same definition:
  • all VOCs can be considered TOCs, however, not all TOCs are considered VOCs.
• base the VOC emissions on the total mass of all VOC substances emitted annually 
• Part 1 of the substance list includes 93 substances or groups of substances that meet the VOC definition:
  • individual reports must be submitted for each of these VOCs that meet the Part 1 criteria (based on quantities manufactured, processed or otherwise used)
  • regardless of whether the Part 1 criteria are met, any releases to air of these substances must also be included in threshold calculations for Part 4 VOCs, along with all other VOCs emitted
• five of the PAHs listed in Part 2 also meet the CEPA definition of a VOC (acenaphthene, acenaphthylene, anthracene, fluorene, and phenanthrene)
  • these PAHs must be included in the calculation for total Part 4 VOCs, and are also subject to Part 2
• when calculating Part 4 total VOCs, include any substance that meets the CEPA definition of VOC, even if it is not listed separately in Part 1 or Part 5
• in addition to total VOCs, facilities may be required to report additional information on speciated VOCs listed in Part 5 (see section 9 for more information)
  • eighteen VOCs are listed on both Part 1 and Part 5 and are subject to reporting requirements for both Parts

8.5 Reporting criteria for Part 4 substances for Case 1 and 2 facilities

The criteria for reporting Part 4 substances and the information to be reported vary depending on the number of employees and the activities that take place at the facility. Facilities can belong to one of the four categories, or “cases”. Case 1 and 2 facilities can be classified under any NAICS code and the criteria for reporting for these facilities are described below:

A facility is Case 1 if:

• it is not a pipeline installation and either:
  • activities to which the employee threshold does not apply takes place (see section 3.4.3)
  • employees work a total ≥ 20,000 hours during the calendar year

A facility is Case 2 if any of the following apply:

• the facility is a pipeline installation where stationary combustion equipment is operated (see section 3.4.2 for the definition of a pipeline installation) 
• employees do not work a total < 20,000 hours during the calendar year and:
  • no activities to which the employee threshold does not apply take place
  • the facility is not in the oil and gas extraction (except oil sands) sector (NAICS 211110)
• the facility is in the oil and gas extraction (except oil sands) sector (NAICS 211110) and consists solely of compression equipment

Case 3 and Case 4 facilities are facilities in the oil and gas extraction (except oil sands) sector (NAICS 211110) and do not meet the employee threshold. Requirements for Case 3 and 4 facilities are not described further in this Guide. For more information on the reporting requirements for oil and gas facilities, see the Oil and gas industry: guide to reporting.

In contrast to the majority of NPRI substances, the thresholds for CAC emissions are based on the quantity released to air. In general, any person who owns or operates a contiguous facility, a portable facility, a pipeline installation or an offshore installation must report for a Part 4 substance if:

1.  the total quantity of the Part 4 substance released to air is greater than or equal to the release threshold specified in Table 6
2. the Case 1 and 2 criteria above are met

For the purposes of determining if Case 2 applies (and for determining which sources need to be included for threshold calculations and which sources need to be reported; see section 8.6), stationary combustion equipment is defined as follows:

8.5.1 Stationary combustion equipment

Stationary combustion equipment includes devices that combust solid, liquid, or gaseous fuel, generally for the purposes of producing electricity, generating steam, or providing useful heat or energy for industrial, commercial, or institutional use, or reducing the volume of waste by removing combustible matter. This includes any combustion equipment that needs to be stationary to function or operate properly, or is not capable of self-propulsion. Both internal and external combustion equipment are included.

8.6 Calculating releases of Part 4 substances

Case 1 facilities must include releases of CACs from all sources when determining if the air release threshold is met. Case 2 facilities are required to include only releases of CACs from stationary combustion equipment when determining if the air release threshold is met. Below are some of the most common sources of CAC emissions:

• abrasive blasting:
  • the process of cleaning or texturing materials with an abrasive material such as sand, coal and smelter slag, as well as mineral, metallic or synthetic abrasives
  • the blasting process itself is a source of PM emissions, especially PM₁₀ and PM_2.5
• equipment leaks:
  • equipment connections, joints and interfaces can be the source of gaseous and liquid releases
  • if the equipment is handling a gaseous stream containing a CAC, the gaseous leak would result in a fugitive CAC release
  • depending on the properties of a liquid (such as vapour pressure, temperature and pressure), a liquid release may also result in a fugitive CAC release
• external combustion equipment:
  • comprises any equipment with a combustion process that occurs at atmospheric pressure and with excess air (see section 8.5.1 for a list of included equipment)
• fermenting:
  • involves the use of yeast, bacteria, enzymes, etc., to break down complex organic compounds
  • many industries use fermentation including:
    • production of bread
    • production of spirits
    • production of pharmaceuticals
    • production of fuel
    • production of beer and wine
    • environmental bioremediation processes
• Internal combustion equipment:
  • any equipment with a combustion process that occurs in a confined space and above atmospheric pressure (see section 8.5.1 for a list of included equipment)
• loading and unloading:
  • fugitive CAC emissions can result from the loading and unloading of vehicles or containers
  • if the material being transferred is a liquid, the resulting emissions would likely be in the form of VOCs
  • if the material is a solid, the resulting emissions would likely be in the form of PM
• painting:
  • VOCs are released from paint during its application and drying
  • PM_2.5 may also be emitted if paint is applied by pulverization
  • this category includes:
    • the painting of vehicles
    • furniture
    • storage tanks
    • any other painted product
• printing:
  • VOCs are released from fixers, developers and solvents used during printing processes
• road dust:
  • TPM, PM₁₀ and PM_2.5 releases from road dust caused by vehicular traffic on unpaved roads within facility boundaries are required to be included in release calculations, when travel on these roads is ≥ 10,000 vehicle kilometres travelled per year
• solvent use:
  • includes, but is not limited to:
    • solvent degreasing
    • waste solvent reclamation
    • product formulation
    • commercial solvent use
• stationary combustion equipment:
  • comprises any combustion equipment that needs to be stationary to function or operate properly, or is not capable of self-propulsion
  • includes both internal and external combustion equipment
• storage piles:
  • generate PM emissions
  • pile moisture content, wind speed, and proportion of aggregate fines influence total emissions from a storage pile
• storage tanks:
  • comprise any storage tanks containing:
    • fuels
    • solvents
    • hydrocarbons
    • paints
    • other solutions that contain VOCs
  • this includes:
    • fixed roof tanks
    • external floating roof tanks
    • domed external floating roof tanks
    • internal floating roof tanks
    • variable vapour space tanks
    • pressure storage tanks

8.6.1 Possible exclusion from reporting CACs for Case 1 and 2 facilities

A facility is not required to submit a report for a CAC, if all the following criteria are met:

• the CAC is released to air only from stationary external combustion equipment
• the cumulative nameplate capacity of all stationary external combustion equipment is less than 10 million BTUs/hour (10.55 million kJ/hour)
• the only type of fuel combusted in that equipment is:
  • commercial grade natural gas
  • liquefied petroleum gas
  • Number 1 or 2 fuel oil
  • any combination thereof

This exclusion does not apply if any other fuels are burned in the stationary external combustion equipment.

For the purposes of determining whether or not this exclusion applies, stationary external combustion equipment and nameplate capacity are defined as follows:

8.7 Reporting releases of Part 4 substances

If the reporting criteria are met for a Part 4 substance, the releases to air of that substance must be reported in tonnes. Facilities that report for one or more CACs must also report their operating schedule (days and hours) and any periods of one week or longer where the facility was shut down.

Case 1 facilities must report all releases from all sources. Case 2 facilities should only report releases from stationary combustion equipment.

Case 1 and 2 facilities may also be required to report CAC releases separately from individual stacks if certain thresholds are met (see Appendix D).

9. Reporting for Part 5 substances – Speciated volatile organic compounds

Part 5 lists 62 VOCs, collectively referred to as “speciated VOCs” (see the NPRI substance list for the complete list). 

9.1 Reporting criteria for Part 5 substances

Like Part 4 substances, speciated VOCs must be reported based on quantities released to air. In general, any person who owns or operates a contiguous facility, a portable facility, a pipeline installation or an offshore installation must submit a report to the NPRI for a Part 5 substance if the total quantity of the Part 5 substance released to air is ≥ 1 tonne.

Section 8.5 above describes the four categories of facilities, or “cases,” that determine which sources must be included in threshold calculations. 

Case 1 facilities must include all releases of speciated VOCs from all sources and activities. If one or more of these Speciated VOCs was released in a quantity ≥ 1 tonne, the owner/operator is required to:

• submit a report for each Part 5 substance that was released to air in a quantity ≥ 1 tonne
• report releases from all sources and activities

Case 2 facilities must include all releases of speciated VOCs only from stationary combustion equipment when determining whether the threshold for a Part 5 substance is met. If one or more of these Speciated VOCs was released in a quantity ≥ 1 tonne, the owner/operator is required to:

• submit a report for each Part 5 substance that was released to air in a quantity ≥ 1 tonne
• report releases from stationary combustion equipment only

Case 3 and Case 4 facilities are facilities in the oil and gas extraction (except oil sands) sector (NAICS 211110) that do not meet the employee threshold. For more information on the reporting requirements for oil and gas facilities, see the Oil and gas industry: guide to reporting.

9.2 Part 5 substance qualifiers

Some Part 5 substances and groups of substances are qualified in terms of what needs to be included when calculating releases. The qualifiers, described below, determine whether a report will be required for a given substance. Supplemental information on speciated VOCs and their isomers is presented in Appendix E.

"all isomers"

Butyl acetate:

• includes:
  • n-butyl acetate (CAS RN 123-86-4)
  • isobutyl acetate (CAS RN 110-19-0)
  • sec-butyl acetate (CAS RN 105-46- 4)
• excludes tert-butyl acetate (CAS RN 540-88-5)

Ethyltoluene includes the total of all isomers of ethyltoluene:

• 2-ethyltoluene (CAS RN 611-14-3)
• 3-ethyltoluene (CAS RN 620-14-4)
• 4-ethyltoluene (CAS RN 622-96-8)

Hexane:

• includes the total of all isomers reported as an aggregate of the individual isomers
• excludes n-hexane (110-54-3)

Propyl acetate includes the total of all isomers of propyl acetate:

• isopropyl acetate (CAS RN 108-21-4)
• propyl acetate (CAS RN 109-60-4)

Trimethylbenzene (CAS RN 25551-13-7):

• includes:
  • 1,2,3-trimethylbenzene (526-73-8)
  • 1,3,5-trimethylbenzene (108-67-8)
• excludes 1,2,4-trimethylbenzene (95-63-6)

Xylene (CAS RN 1330-20-7) includes the total of all isomers of xylene:

• m-xylene (CAS RN 108-38-3)
• o-xylene (CAS RN 95-47-6)
• p-xylene (CAS RN 106-42-3)

The following substances include the total of all isomers reported as an aggregate of the individual isomers:

• butane
• butene (25167-67-3)
• cycloheptane
• cyclohexene
• cyclooctane
• decane
• heptane
• hexene (25264-93-1)
• methylindan (27133- 93-3)
• nonane
• octane
• pentane
• pentene
• propylene glycol methyl ether acetate (108-65-1)

"and their isomers"

Other glycol ethers and acetates include the total of the following CAS RNs and their isomers:

• 112-07-2
• 112-15-2
• 112-25-4
• 112-34-5
• 5131-66-8
• 107-98-2
• 109-59-1
• 111-90-0
• 124-17-4
• 1569-01-3
• 1569-02-4
• 2807-30-9
• 29911-27-1
• 29911-28-2
• 34590-94-8
• 54839-24-6
• 623-84-7
• 88917-22

Note that there is some overlap between the individual substances, isomer groups and other groups and mixtures listed in Part 5. For example, all isomers of decane are C₁₀ hydrocarbons, therefore they also meet the definition of analytically unresolved hydrocarbons (C₁₀ to C₁₆₊) (URHCs). URHCs are an agglomeration of volatile organic compounds in the C₁₀ to C₁₆₊ range that could not be separated into individual components by the selected gas chromatography column. 

Where there is overlap between different sections of the Part 5 list, information on individual substances should be reported if it is available. If information on individual substances is not available, but information on the total for an isomer group is available, the total for the isomer group should be reported. If information on the individual substance and the isomer group is not available, then information on URHCs should be reported if this range of species is appropriate. 

Do not report the same quantity of a substance more than once within Part 5. For example, if the quantity of isomers of decane released to air is included as part of the total amount reported for isomers of decane, do not include that same quantity in the reported amount of URHCs.

Also note that there are 143 VOCs listed in Parts 1 and 2 of the NPRI substance list, many of which are C₁₀ to C₁₆₊ hydrocarbons. If thresholds are met for these substances, they should be reported in both Part 1 or 2 and Part 5 (either as an individual substance or isomer group that is on the Part 5 list, or as part of URHCs). For example, if the Part 1 threshold for naphthalene (C₁₀H₈) is met, releases of naphthalene must be reported under Part 1. Since naphthalene is not listed individually in Part 5, the quantity of naphthalene released to air should be included in the total URHCs reported under Part 5, if the thresholds for Parts 4 and 5 are met. In this case, the same quantity of naphthalene that is released to air will be reported twice.

9.3 Calculating releases of Part 5 substances

Case 1 facilities must include releases of speciated VOCs from all sources when determining if the air release threshold is met. Case 2 facilities are required to include only releases of speciated VOCs from stationary combustion equipment when determining if the air release threshold is met. 

Exclusion from reporting VOCs for Case 1 and 2 facilities

A facility is not required to submit a report for VOCs, if all the following criteria are met:

• the VOC is released to air only from stationary external combustion equipment
• the cumulative nameplate capacity of all stationary external combustion equipment is less than 10 million BTUs/hour (10.55 million kJ/hour)
• the only type of fuel combusted in that equipment is commercial grade natural gas, liquefied petroleum gas, Number 1 or 2 fuel oil, or any combination thereof

This exclusion does not apply if any other fuels are burned in the stationary external combustion equipment.

For the purposes of determining whether or not this exclusion applies, stationary external combustion equipment and nameplate capacity are defined as follows:

Stationary external combustion equipment: Any stationary equipment with a combustion process that occurs at atmospheric pressure and with excess air. This may include thermal electric generating plants, industrial boilers, and commercial and domestic combustion units.

Nameplate capacity: The total designed energy input capacity of the stationary, external combustion equipment. Cumulative nameplate capacity refers to the total nameplate capacities of all stationary external combustion equipment at the facility.

9.4 Reporting releases of Part 5 substances

If the reporting criteria are met for a Part 5 substance, the releases to air of that substance must be reported in tonnes.

Case 1 facilities must report all releases from all sources. Case 2 facilities should only report releases from stationary combustion equipment.

Case 1 and 2 facilities may also be required to report speciated VOC releases separately from individual stacks if certain thresholds are met (see Appendix D).

Unlike Parts 1 through 4 substances, where releases to air must be reported separately in several categories (i.e., stack or point releases, storage tank and related handling releases, fugitive releases, etc.; see section 10.3), releases of speciated VOCs must be reported as

• The total for each individual stack that meets thresholds (see Appendix D)
• The total of all other releases that are not from individual stacks that meet thresholds

10. Glossary

10.1 Types of facilities

10.2 Manufacture, process and otherwise use

10.3 Release, disposal, and recycling categories

10.3.1 On-site releases

A discharge of a substance to the environment within the physical boundaries of the facility. This includes releases to air, surface waters and land. Routine releases (e.g., fugitive releases) and accidental or non-routine releases (e.g., spills) are included. Releases do not include on-site or off-site disposals or off-site transfers for recycling.

Releases to air

Releases to surface waters

Releases to oceans, lakes, wetlands, rivers, streams, etc. are included.

Releases to land

Releases to land include surface and underground releases which occur at a facility.

10.3.2 Disposals

The final disposal to landfill, land application or underground injection, either on the facility site or at a location off the facility site; transfer to a location off the facility site for storage or treatment prior to final disposal; or movement into an area where tailings or waste rock are discarded or stored, and further managed to reduce or prevent releases to air, water or land, either on the facility site or at a location off the facility site. The disposal of a substance is different from a direct release to air, water or land.

On-site disposals

Off-site disposals

Off-site disposals include total quantities that are transferred off the facility site for final disposal.

Tailings and waste rock

10.3.3 Transfers

An NPRI-listed substance may be transferred to a location off the facility site for treatment prior to final disposal or for recycling and energy recovery.

Off-site transfers for treatment prior to final disposal

Treatment means subjecting the substance to physical, chemical, biological or thermal processes.

Off-site transfers for recycling and energy recovery

Recycling refers to activities that keep a material or a component of the material from becoming a waste destined for final disposal. Recyclable materials may be cleaned, regenerated or reprocessed to their original specifications and reused for their original purpose. They may also be used for an entirely different purpose without any pre-treatment or modification. Components may be recovered or reclaimed from the recyclable material or the material may be used as a fuel for energy recovery. The recyclable material may be used in the manufacture of another product. 

For the purposes of the NPRI, recycling also includes substances sent back to a manufacturer, supplier or recycler for reprocessing, repackaging, resale or for credit or payment. For example, metal shavings or turnings that are sold to a recycler are considered to be transfers off-site for recycling. The categories of recycling listed in the NPRI are:

• energy recovery
• recovery of solvents
• recovery of organic substances (not solvents)
• recovery of metals and metal compounds
• recovery of inorganic materials (not metals)
• recovery of acids or bases
• recovery of catalysts
• recovery of pollution abatement residues
• refining or reuse of used oil
• other recovery, reuse or recycling activities

10.4 Activities to which the employee threshold does not apply

10.4.1 Incineration

A waste incinerator is a device, mechanism or structure constructed primarily to thermally treat waste for the purpose of reducing its volume, or destroying hazardous chemicals or pathogens present in the waste. This includes facilities where waste heat is recovered as a by-product from the exhaust gases of an incinerator (e.g., energy-from-waste incinerators), conical burners and beehive burners. This does not include industrial processes where fuel derived from waste is fired as an energy source, such as industrial boilers. For example, if bark, wood chips or other wood waste are used as fuel to fire a boiler, these activities are not considered energy-from-waste incinerators.

10.4.2 Other activities

10.5 Activities that trigger reporting of Part 3 substances (dioxins, furans and hexachlorobenzene), if the employee threshold is met

10.5.1 Combustion

10.5.2 Smelting

Smelting is the melting of raw or scrap materials to produce metal for further processing into metal products. The smelting process is typically accompanied by a chemical change in which impurities are removed.

10.5.3 Manufacturing/production

10.6 Combustion and fuel use

10.6.1 Categories of individual stack and flare releases

10.6.2 Exclusion for reporting Part 4 substances – Case 1 and 2 facilities

10.6.3 Determining sources to include in threshold calculations and to report – Case 2 facilities

10.7 Other NPRI terms

11. Bibliography

• American Society for Testing and Materials (2002) Standard Practice for Determination of a Pooled Limit of Quantification, D6259-98.
• Environment Canada (1997). Determination of LoQs for Measuring Hexachlorobenzene in Selected Solvents. Draft Report AAQD 97-01, Analysis and Air Quality Division, Environmental Technology Centre.
• Environment Canada (1999). Level of Quantification Determination: PCDD/PCDF and Hexachlorobenzene. Analysis and Air Quality Division, Environmental Technology Centre. 
• Environment Canada (2000). Determination of Level of Quantification for Measuring HCB and PCDD/PCDF in Soil, Draft. Analysis and Air Quality Division, Environmental Technology Centre.

Appendix A – Substance list

The complete list of NPRI substances can be found on the NPRI website and in the Canada Gazette, Part II Notice with respect to the substances in the National Pollutant Release Inventory for 2025, 2026 and 2027.

Appendix B – example calculations

B.1 Calculating the manufacture, process or otherwise use quantity

Table 7 illustrates the calculation of the reporting threshold for a Part 1A substance. In the example, a facility has several processes in which a Part 1A substance is manufactured, processed or otherwise used. The substance is also released as a by-product and is contained in tailings and waste rock.

This example assumes that the employee threshold is met, or an activity to which the employee threshold does not apply takes place at the facility. In this case, a report is required for this substance, because the total quantity of the Part 1A substance manufactured, processed, otherwise used, and contained in tailings and waste rock at the facility exceeded 10 tonnes, as explained below.

Total to include in threshold calculation: 12.9 tonnes.

1. In process A, the Part 1A substance is present at 5% concentration (or equivalent weight for metallic compounds) and is included in the threshold calculation
2. In process B, the raw material added to the process is a pure substance
   • it is included in the threshold calculation, regardless of any subsequent dilution in the process
3. The weight of the substance in the raw material used in process C is not included in the threshold calculation because the concentration is less than 1%
   • note that, as a report is required in this example, the releases, disposals and transfers for recycling from all processes, including process C, are required to be reported, regardless of concentration and regardless of whether or not the quantity is used in the threshold calculation
4. The weight of the substance produced and released from process D is included in the calculation because it is a by-product, and the concentration threshold does not apply
5. The weight of the substance contained in tailings is included in the threshold calculation because there is no concentration threshold for tailings
6. The weight of the substance contained in waste rock is not included in the threshold calculation, because the concentration of the substance in the waste rock is less than 1%
   • the weight of the substance in the waste rock would also not be included when calculating disposals of the substance, because the concentration is less than 1%
7. The total is the value that must be compared to the 10 tonnes reporting threshold
   • this value is only used to determine that a report is required for the Part 1A substance
   • a subsequent calculation must be done to obtain the actual value of releases, disposals, and transfers for recycling that must be reported

B.2 Calculating releases using continuous emissions monitoring

This example estimates emissions from an oil-fired boiler that has the example continuous emission monitoring (CEM) data in Table 8.

Where: 

• measured concentration = C 
• calculated emission rate = CER

The following equation is used to calculate emissions from the measured concentrations:

Where:

• CER_x = calculated emission rate of contaminant "x", kg/hr
• C_x = Concentration of contaminant "x", ppmvd
• MW_x = Molecular weight of the contaminant "x", g/g-mole
  • MWSO₂ = 64
  • MWNOx = 46 (as MWNO₂)
  • MWCO = 28
• Q_stack = Dry stack gas volumetric flow rate at reference conditions (101.325 kPa and 25°C), dRm³/min 
• V = Volume occupied by 1 mole of ideal gas at reference conditions (24.45 litres/g-mole)

The average SO₂ emissions for the 1 hour CEM period:

B.3 Calculating releases using predictive emissions monitoring

TPM emissions from a boiler firing heavy fuel oil (HFO) are estimated in this example. To use the PEM approach, a model or relationship between TPM emission rates and fuel consumption must first be developed. An example of a model relationship is shown below.

Correlate the TPM emission rates to the HFO consumption rate of the boiler in the PEM as listed in Table 9.

Once the predictive model has been tested and verified it can then be used along with the fuel use consumption rate to estimate annual TPM emissions from the unit. Table 10 illustrates how the predictive model is used to estimate TPM emissions for a specific time period.

The general formula for estimating emissions for contaminant "x" is:

Where:

• E_x = Emission of contaminant "x", kg/year
• E_x,ave = Average emission rate of contaminant "x", kg/hr
• T = Total operating hours in a given year

Given that the above boiler unit operated under the same condition for 7,500 hours in the year, the estimated TPM emissions would be:

B.4 Calculating releases using source testing

This source testing example is based on measured concentrations of the substance in a waste stream and the volume/flow rate of that stream. A galvanizing facility discharges its wastewater to a nearby body of water. The electroplater is required to monitor this discharge once a month for various parameters, including the release of total zinc.

Step 1: Gather wastewater flow and concentration data from the monitoring results done in compliance with the municipal by-law for wastewater discharges. Analytical results for total zinc for the year are presented in Table 11.

Step 2: Calculate the mass loading for those days on which a zinc analysis was performed. This is done by multiplying the daily flow by the measured zinc concentration.

Step 3: Calculate annual releases. Based on an average daily release of 1.21 kg over the year and 250 days of discharge during the year, the yearly total zinc discharged to water:

B.5 Calculating releases using source testing, levels of quantification and toxic equivalency factors

At this facility, 200 tonnes of non-hazardous waste were incinerated during the year, with a waste feed rate of 100 kg/hr. The stack flow rate was 1.2 m³/s. The facility has stack testing data for dioxins/furans. The measured stack gas concentrations of dioxins/furans in the air were:

• 4.0 ng/m³ of 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin
• 7.0 ng/m³ of 1,2,3,4,7,8-hexachlorodibenzofuran
• 10.0 ng/m³ of 1,2,3,6,7,8-hexachlorodibenzofuran

The facility produced 20 tonnes of incineration ash in the year which was shipped off site for disposal in a landfill. The facility has measured an average dioxins/furans concentration of:

• 2.5 mg/tonne ash of 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin
• 4.6 mg/tonne ash of 1,2,3,4,7,8-hexachlorodibenzofuran
• 8.1 mg/tonne ash of 1,2,3,6,7,8-hexachlorodibenzofuran

Step 1: Determine if the equivalent measured concentration of dioxins/furans releases to air was greater than the LoQ of 32 pg TEQ/m³

This facility is required to report releases to air for the individual congeners since the measured concentration of 2,100 pg TEQ/m³ was greater than the LoQ of 32 pg TEQ/m³.

Step 2: Calculate the hours of operation

Step 3: Calculate the quantity of dioxins/furans congeners released to the air, for example, 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin:

Step 4: Determine if the measured concentration of dioxins/furans in the incineration ash was greater than the LoQ of 9 pg TEQ/g ash:

The measured concentration of 1,520 pg TEQ/g ash was greater than the LoQ for dioxins/furans in ash of 9 pg TEQ/g ash; therefore the quantity of each individual congener in ash sent for off-site disposal must be reported in grams.

Step 5: Calculate the quantity of dioxins/furans congeners contained in the incineration ash that was sent for off-site disposal

B.6 Calculating releases using mass balance

An electroplating facility operates a vapour degreaser. Suppose that 14 tonnes of trichloroethylene are used as a degreasing agent. Spent solvent and sludge that accumulate on the bottom of the degreaser are collected in drums for shipment to an off-site solvent reclaimer. Thirteen drums of solvent were sent to the reclaimer during the past year.

A known volume of a representative sample taken from the drums is weighed, allowed to evaporate, and reweighed. From this, it is determined that the density of the sludge is 1.03 kg/L and that the trichloroethylene concentration in the sludge shipped to the reclaimer is 30%.

Step 1: The entire 14 tonnes of solvent is released from the facility either as an air emission or as a transfer in the sludge. If the quantity of spent solvent shipped to the reclaimer is known, then the quantity transferred can be calculated based on the volume of sludge and the density of the sludge as shown below:

Step 2: The quantity of trichloroethylene emitted to air can then be calculated by mass balance by subtracting the quantity shipped in sludge to the reclaimer from the quantity purchased:

Note: trichloroethylene is a VOC and the quantity released to air in this example would also require that a report for total VOCs under Part 4 be submitted. 

B.7 Calculating releases using emission factors

A facility operated a cement kiln and process throughput amounted to 2,500,000 tonnes of clinker produced during the year. In this example, the facility uses the emission factors provided in the WebFIRE database, to calculate the quantities of the individual PAHs that were incidentally manufactured and released, disposed of, or transferred for recycling. For a throughput of 2,500,000 tonnes of clinker, the following quantities of individual PAHs that are released to air are shown in Table 12.

The quantity of the individual PAHs resulting from incidental manufacture totaled more than 50 kg, so the facility has met the reporting threshold for PAHs, and must report those substances which have met the 5 kg threshold.

The facility must submit a substance report to the NPRI for two of the PAHs for which there are data. The substance reports and quantity reported for on-site releases to air are: 6.05 kg of fluoranthene, and 42.25 kg of phenanthrene. No report is required for pyrene because it did not meet the 5 kg threshold. No report is required for the individual PAHs for which there are no emission factors [e.g., benz(a)anthracene]. The releases are not reported under the listing "PAHs, total unspeciated (NA - P/H)" because the facility has information for some of the individual Part 2 PAHs.

There were no releases to water or land of any incidentally manufactured PAHs, so the facility reports no releases to these media.

There is no knowledge of the quantity of incidentally manufactured PAHs in the residue from the pollution control devices (e.g., electrostatic precipitator), so the facility reports no disposals of the three PAHs. 

Note: In cases where multiple process streams are present, but information on individual PAH is not available for all streams, report information on the individual PAHs and report the remaining quantity under total PAHs, i.e. "PAHs, total unspeciated (NA - P/H)." Quantities reported as individual PAHs should not be included in the quantity reported for "PAHs, total unspeciated (NA - P/H)."

B.8 Calculating releases using a speciation profile

A facility that manufactures varnish is able to calculate total VOC releases of 26.71 tonnes using an emission factor. The US Environmental Protection Agency’s SPECIATE 5.1 database contains a speciation profile that can be used to estimate releases of speciated VOCs based on the total VOCs quantity. Profile number 0066, for “Varnish Manufacturing – Bodying Oil,” is based on total organic gas (TOG), which includes compounds that are not considered to be VOCs under the ECCC definition (e.g., methane and ethane). For SPECIATE profiles that are based on TOG, the TOG to VOC ratio must applied to the annual release value before applying the profile weight percentage to derive the quantity of each VOC species released:

In this example, the quantity of methyl ethyl ketone released would be calculated as:

The quantity of methyl isobutyl ketone released would be calculated as:

B.9 Calculating releases using engineering estimates

This estimation method is based on physical/chemical properties (e.g., vapour pressure) of the substance and mathematical relationships (e.g., ideal gas law). In this example, rinse water from a copper-plating unit is treated separately from other process wastewater. Sodium hydroxide is added to precipitate the copper (Cu) in the wastewater. The precipitate formed from this reaction is removed as sludge from the facility's central clarification unit. Purchasing and inventory records indicate that 0.9 tonnes of sodium hydroxide were used for precipitating copper last year. The quantity of copper precipitated represents the quantity of copper released from this source as solid waste.

Step 1: For each mole of copper (Cu) present in the rinse water, two moles of sodium hydroxide (NaOH) must be added to precipitate the copper according to the following reaction:

Scientific literature indicates that this reaction would be complete at a pH of 7.7. Sodium hydroxide is added until a pH of 8 is maintained in the reaction mixture to ensure complete precipitation. It is also known that:

Step 2: Calculate the quantity of copper released in the wastewater treatment sludge:

The ratio of NaOH to Cu by mass is calculated as follows:

Using the proportions above, the following equation can be derived:

Where A = the quantity of copper released in the wastewater.

The estimation method is valid only if the NaOH reacts only with the Cu present in the wastewater and the reaction is complete.

B.10 Calculating total reduced sulphur releases using hydrogen sulphide equivalence factors

Total reduced Sulphur (TRS) refers to a gaseous mixture of compounds containing one or more sulphur atoms in their reduced state. For the purposes of reporting to the NPRI, this grouping is restricted to the substances listed in Table 13 below. TRS must be expressed in terms of H₂S equivalents, and H₂S equivalence factors are shown in Table 14.

It is important to remember that three of these TRS compounds – hydrogen sulphide (H₂S), carbon disulphide (CS) and carbonyl sulphide (COS) – are also listed individually under Part 1A. If any one of these three substances meets the 10 tonne reporting threshold, that substance must also be reported individually.

To use the equivalence factor method to calculate TRS, each TRS compound is converted into the H₂S equivalent. The equivalent amounts are then summed and compared to the 10 tonnes MPO threshold. If the threshold is met or exceeded, a TRS substance report is required. 

Table 14 illustrates how to calculate TRS using the equivalence factor method, when quantities of each of the six TRS substances are available. To calculate the amounts expressed as H₂S, add the quantities of the substances multiplied by the H₂S applicable equivalence factors:

B.11 Converting CAC releases from ppm (volume) to tonnes

Stack test results for NO_x (expressed as NO₂), CO, or SO₂ are usually in units of parts per million volume or ppm (volume). Before these numbers can be used to estimate releases of these substances for the NPRI they need to be converted from ppm (volume) to a mass release in tonnes.

Step 1: Calculate the stack's volumetric gas flow rate (V̇):

Step 2: Correct the stack gas flow rate for the moisture content and standard conditions:

Example: If the stack gas volumetric flow is 1,330 m³/min at 80°C and 1 atm pressure with a moisture content of 10%, the dry volumetric stack flow rate is:

Step 3: Convert from ppm (volume) to mass emission rate (kg/h):

Example: NOx is emitted from a stack that is 2.1 ppm by volume. The dry volumetric stack flow rate is 925.84 m³/min. The density of air at standard conditions is 1.29 kg/m³.

Step 4: Use the mass emission rate to calculate the yearly NOx release.

B.12 Converting CAC releases from ppm (mass) to tonnes

Stack test results for total particulate matter (TPM), PM₁₀ or PM_2.5 are usually in units of parts per million mass or ppm (mass). Before these numbers can be used to estimate releases of these substances for the NPRI, they need to be converted from ppm (mass) to a mass release in tonnes.

Step 1: Convert from ppm (mass) to the mass emission rate by converting ppm to grams/tonne and using the stack mass flow rate (kg/min) to convert to mass emission rate. 

Example: The TPM emission rate from the stack is 250 ppm (mass). The dry mass flow rate is 10.54 kg/min. The stack is operational 24 hours a day, 365 days a year, i.e., 525,600 minutes per year.

Step 2: Using stack dry mass flow rate, calculate the mass emission rate

Step 3: Use the mass emission rate to calculate the yearly TPM release

B.13 Converting CAC releases from mass per volume to tonnes

Stack test results for volatile organic compounds (VOCs) are usually in units of mass per volume, e.g., µg/m³. These numbers need to be converted to an annual mass release in tonnes.

Step 1: Calculate the stack's volumetric gas flow rate (V̇):

Step 2: Correct the stack gas flow rate for the moisture content and standard conditions:

Example: If the stack gas volumetric flow is 1,330 m³/min at 80°C and 1 atm pressure with a moisture content of 10%, the dry volumetric stack flow rate is:

Step 3: Use the stack flow rate (m³/min) to convert to a mass emission rate.

Example: VOCs are emitted from a stack at a rate of 60 µg/m³. The dry volumetric stack flow rate is 925.84 m³/min:

Step 4: Use the mass emission rate to calculate the yearly VOCs release

B.14 Calculating CAC releases from source testing and fuel consumption data

Many facilities participating in a stack testing program will have information on the fuel feed rate during the test period and total annual fuel consumption. This data can be used to more accurately estimate CAC releases taking into account the process variations and production rates. For example, this method may be used if the equipment is only operational for part of the year or the fuel feed rate fluctuates based on the facility's production rate.

To illustrate this method the data in from the example in section B.12 was assigned to a boiler burning bituminous coal.

Step 1: Convert from ppm (mass) to the mass emission rate and, using the stack dry mass flow rate, calculate the mass emission rate, then convert to grams per hour (see section B.12). This results in a mass emission rate of 158.1 g/hr.

Step 2: Use the mass emission rate and the boiler fuel feed rate to create CAC production rate to fuel consumption to create an emission factor 

Example: The TPM emissions being released from the stack are the result of combustion in a bituminous coal fired boiler. The stack testing results were based on a one-hour test period. The fuel feed rate of the boiler during the test was 25 kg bituminous coal per hour.

Step 3: Use the emission factor calculated above along with the boiler's specific total annual consumption of bituminous coal.

Example: The boiler in question burned 218.85 tonnes of bituminous coal in the reporting year. The calculated emission factor for TPM for this boiler was 6.324 kg per tonne bituminous coal burned.

B.15 Calculating CAC releases from source testing and total production data

Another method that can be used to estimate CAC releases is to correlate stack testing data with the facility's production data. Most facilities participating in a stack testing program will have information on the production rate during the test period and total annual production. This data can be used to more accurately estimate CAC releases, taking into account the process variations and production rates. For example, this method can be used if the process line is only operational for part of the year or the production rate fluctuates with demand for the product.

To illustrate this method, the data from the example in section B.13 was assigned to the fluidized bed prilling process used in urea production.

Step 1: Calculate the stack's volumetric gas flow rate (V̇) and correct the stack gas flow rate for the moisture content and standard conditions (see section B.13). This results in a dry stack volumetric gas flow rate of 925.84 m³/min.

Step 2: Use the stack flow rate (m³/min) to convert to a mass emission rate.

Example: VOCs are emitted from a stack at a rate of 60 µg/m³. The dry volumetric stack flow rate is 925.84 m³/min.

Step 3: Use the mass emission rate and the facility's production rate to create an emission factor for CAC releases to total production

The facility's production rate can be in tonnes product produced, number of units produced or any other applicable measure of production. Likewise, the CAC release could be in any units of mass. This example will use tonnes product produced and grams of substance released to illustrate the process.

Example: The VOC emissions being released from the stack are the result of the fluidized bed prilling processes used in urea production. The stack testing results were based on a one-hour test period. The production rate of the facility during the test was 23 tonnes of urea per hour.

Step 4: Use the emission factor calculated above along with the facility's total annual production of urea.

Example: The facility in question produces a total of 203,210 tonnes of urea in the reporting year. The emission factor, calculated above, for VOCs from the fluidized bed prilling process, was 0.145 g per tonne urea produced.

Appendix C - conversion factors

Appendix D – reporting requirements for individual stacks

D.1 Reporting criteria for individual stacks

CAC and speciated VOC releases to air must be assigned to individual stacks or flares when all of the following criteria are met:

• the facility-wide release threshold is met (see Table 18)
• the stack release threshold is met (see Table 18)
• the height of the stack or the effective height of the flare is ≥ 25 m or more above grade
  • including the height of any building that the stack or flare is on
• The annual average exit temperature of the stack or flare is either not measured or is ≥ 50°C or more

Note that the threshold for the average annual exit temperature can only be applied if the exit temperature is determined through measurement. Estimations, values supplied by manufacturers, values used for the purposes of obtaining an operating approval or permit and default values cannot be used to compare to the temperature threshold. 

D.2 Reporting releases of criteria air contaminants from individual stacks

If the reporting criteria are met for a stack or flare, releases to air of that CAC must be assigned to that stack or flare.

Case 1 facilities must report all releases from all sources. Case 2 facilities should only report releases from stationary combustion equipment.

D.2.1 Releases from specified sources

Quantities of CACs released from each stack that meets the criteria must be reported separately for each of the following categories, defined below:

1. stationary fuel combustion for energy purposes
2. combustion of fuels for non-energy purposes 
3. flaring
4. use of fuels for non-energy products
5. releases from all other sources not included in the above categories

Where possible, in instances where industrial process emissions are produced in combination with emissions from fuel combusted to supply energy, the emissions are to be calculated and reported separately. In cases where it is not possible to calculate emissions separately, co-mingled emissions would be reported based on the primary purpose of the unit of operation. Facilities must provide a detailed comment to explain that combined emissions are being reported, including an estimate of the percentage contribution of each category where possible.

Stationary fuel combustion for energy purposes

Stationary fuel combustion emissions: emissions resulting from the oxidation of solid, liquid, and gaseous fuels from stationary fuel combustion sources for the purpose of producing heat or work (electricity and thermal and mechanical energy). 

Stationary fuel combustion sources: stationary devices that combust either a mix of or a specific type of solid, liquid, gaseous and waste fuels for the purpose of producing heat or work (electricity, and thermal and mechanical energy). This includes:

• boilers
• electricity generating units
• cogeneration units
• combustion turbines
• engines
• incinerators with heat capture and use
• heaters
• kilns
• furnaces
• burners
• ovens (including coke ovens)
• dryers
• any other stationary combustion devices

Note that flares are not considered stationary fuel combustion sources.

Combustion of fuels for non-energy purposes 

Releases resulting from the oxidation of a fuel not for generating heat or work, for example, when the fuel is used as a reductant. When a fuel is used as both reductant and fuel in a process, the corresponding release would be considered for non-energy purposes; examples include blast furnaces in iron and steel plants, and smelting of base metals. Incineration without energy recovery falls into this category.

Flaring

Flaring emissions: releases resulting from the controlled combustion of a gas or liquid stream produced at the facility, the purpose of which is not to produce useful heat or work. This includes releases from: 

• waste petroleum incineration
• hazardous emission prevention systems (in pilot or active mode)
• well testing
• natural gas gathering systems
• natural gas processing plant operations
• crude oil production
• pipeline operations
• petroleum refining
• chemical fertilizer production
• steel production

Use of fuels for non-energy products

Releases resulting from the use of a fuel as an input to a chemical reaction to produce a non-energy product, such as the production of hydrogen (in stand-alone hydrogen plants only), ammonia or ethylene.

Releases from all other sources not included in the above categories

Any other activities that generate stack releases that are not covered under one of the above categories. This applies to Case 1 facilities only, which must report for all sources of emissions if thresholds are met. Case 2 facilities are only required to report combustion emissions under one or more of the categories above.

D.2.2 Fuel type(s)

Where a release quantity is reported for a stack under any of the first four source categories described above, the type(s) of fuel associated with the releases must also be reported. For the purposes of reporting to the NPRI, fuels are categorized as follows:

• solid fossil fuels
• liquid fossil fuels – refined petroleum products
• gaseous fossil fuels
• natural gas liquids
• industrial production by-products used as fuel
• biomass/biofuels
• waste materials
• other fuels

Definitions of each of the fuel types are provided in the following sections.

Solid fossil fuels

Liquid fossil fuels – refined petroleum products

Gaseous fossil fuels

Natural gas liquids

Industrial production by-products used as fuel

Biomass/biofuels

Waste materials

Other fuels

Any other substances or materials used as fuel that does not fall under any of the categories described above.

D.3 Reporting releases of speciated VOCs from individual stacks

The total quantity of each speciated VOC must be reported for each individual stack that meets thresholds. Unlike total VOCs under Part 4, quantities of speciated VOCs do not need to be reported separately by source and the fuel type(s) associated with speciated VOC releases do not need to be reported.

Case 1 facilities must report all releases from all sources. Case 2 facilities should only report releases from stationary combustion equipment

D.4  Information on stacks and flares to be reported

D.4.1 Stack/flare identification

Stack name

Each stack/flare is required to have a name, which should be as descriptive as possible to help users of the data better understand the purpose of the stack/flare and the sources associated with it. 

Latitude and longitude

The latitude and longitude of each stack/flare must be reported in decimal degrees to at least five decimal places. 

Provincial or territorial identification number(s)

The provincial or territorial identification number (e.g., as specified in a provincial or territorial approval or permit) for each stack/flare must be reported, where available or applicable.

D.4.2 Stack parameters (excluding flares)

Stack parameters that are reported to the NPRI should be based on measurements or estimations made at the source or in similar installations, or on values supplied by manufacturers. Default values used for modelling and permissible maximum values should not be used. Calculations may be made, based upon specific equations, to develop representative values for the effective stack parameters (see below), however this is typically only done in the case of flares. For other (i.e., non-flare) stacks, the use of representative/effective stack parameters generally should not be the norm.

Stack height

The physical height of the stack (in metres) from ground level to the level at which emissions occur. This is also referred to as the height of the stack above grade. The physical height of the stack is determined by taking the measurement from ground level to the exit level of the stack. If a stack is located on top of a building, the height of the building must be added to the height of the stack.

Stack exit diameter 

The inner physical diameter (in metres) at the exit level of the stack. 

If the opening at the top of the stack is circular, stack exit diameter can be calculated as follows:

Where:  

• d = diameter (m)
• A = cross-sectional area (m²)
• π = 3.1416 (approximately)

If the opening at the top of the stack is not circular, equivalent diameter and hydraulic diameter can be calculated as follows:

Where:  

• d_eq = equivalent diameter (m)
• L = length (m)
• W = width (m)
• π = 3.1416 (approximately) 

Where:  

• d_h = hydraulic diameter (m)
• L = length (m)
• W = width (m)

Average stack exit velocity

The annual average exit velocity (in metres/second) of the gas where it exits the stack.

If unknown, the stack exit velocity can be computed from flow rate and stack diameter for rectangular and circular stacks as follows:

Where:  

• v = exit velocity (m/s)
• V̇ = volumetric flow rate (m³/s)
• A = stack area (m²)

Where:

• v = exit velocity (m/s) 
• Q = flow rate (m³/s) 
• π = 3.1416 (approximately)
• d_s = stack exit diameter (m) 

Exit temperature

The annual average temperature [in degrees Celsius (°C)] of the released gas when it exits the stack, if known. If the actual temperature is not known, the facility can report the annual average stack exit temperature that was used for the purposes of obtaining a current approval or a permit, or can indicate that the annual average exit temperature is unknown. Due to the wide variety of possible non-flare stacks, ECCC does not recommend a default exit temperature for non-flare stacks.

D.4.3 Flare parameters

The unique exhaust characteristics of flares necessitate the calculation and use of exhaust effective “pseudo-parameters” to appropriately characterize the flare, in order to ensure that the resulting plume rise and plume spread are reasonably representative. The pseudo-stack parameters that are required are:

1. effective stack height
2. effective stack diameter
3. effective stack exit velocity
4. effective stack exit temperature

It is these pseudo stack parameters that are required – not the actual dimensions of the flare (i.e., actual flare height or actual flare diameter) or conditions at the flare nozzle (i.e. flare exit velocity, flare exit temperature).

Facilities should refer to guidance that has been provided directly by their respective provincial ministry of the environment or contained in the air emissions dispersion guidance document that is available in their province, if such guidance is available. This guidance may have already been used by facilities for air dispersion modelling activities that the facility has been required to undertake in support of their operating permit. The same values should be reported to the NPRI.

In the absence of such provincial guidance, facilities can use the following Ontario Ministry of the Environment and Climate Change guidance (PDF) to determine pseudo-parameters for flares.

Effective stack height

The following equations should be used to estimate the effective stack height:

Where:

• H_eff = effective stack height (m)
  • includes the physical stack height plus the flame length
  • assumes 45° flame tilt due to wind
• H_s = physical stack height above ground (m)
• Q_n = net heat released (J/s)
• Q_T = total heat available from combustion (J/s)
  • sensible and radiative heat available estimated based on the properties of the flared gas stream including the pilot fuel and combustible lift gas
• 𝒇 = % heat lost by radiation
  • a function of the molecular weight of the flared gas stream
  • flares with smoky, dark plumes lose more heat via radiation (i.e., higher value for f) than clean burning flares with no visible plumes

Ranges of molecular weights of the gas stream to be flared corresponding to a given 𝒇 value are outlined in Table 19 [Ontario Ministry of the Environment and Climate Change (OMECC), 2017]. Facilities should calculate the molecular weight of their flared gas stream, based on the documented and/or measured composition considering all potential chemical constituents (e.g., flare gas, non-inert lift or sweep gas, etc.) and then select the corresponding 𝒇 value. In the absence of sufficient documentation to verify or support the composition and calculation of the molecular weight, facilities should use an 𝒇 value of 55% in calculations.

Effective stack diameter

If province-specific guidance is not available, the following equation should be used to estimate the effective stack diameter (OMECC, 2017):

Where:

• d_eff = effective diameter at the flame tip (m)
• F_b,actual = buoyancy flux (m⁴/s³) 
• T_stack = combusted gas temperature (K) [Ontario assumes 1273 K] 
• g = acceleration due to gravity (9.81 m/s²)
• v_eff = effective velocity at the flame tip (m/s) [minimum value = 1.5 m/s]
• T_amb = ambient temperature (K)

Effective stack exit velocity

If province-specific guidance is not available, the following equation should be used to estimate the effective stack diameter (OMECC, 2017):

Where:

• v_eff = effective velocity at the flame tip (m/s) 
• g = acceleration due to gravity (9.81 m/s²)
• F_m = momentum flux (m⁴/s²) 
• F_b = buoyancy flux (m⁴/s³)
• T_stack = combusted gas temperature (K) [Ontario assumes 1273 K]
• T_amb = ambient temperature (K)

Where:

• F_m = momentum flux (m⁴/s²) 
• ρ_gas = density of gas to be flared (kg/m³)
• ρ_air = density of ambient air (kg/m³) 
• d_nozzle = flare nozzle diameter (m)  
• v_nozzle = actual gas exit velocity (including lift gas) at flare nozzle before combustion (m/s)

Where:

• F_b = buoyancy flux (m⁴/s³) 
• g = acceleration due to gravity (9.81 m/s²) 
• Q_n = net heat release rate (J/s)
• ρ_air = density of air at ambient temperature and pressure (kg/m³)  
• T_amb = ambient temperature (K)
• C_p,air = specific heat of dry air constant at T_amb (J/kg-K) 

If information is not available to a facility to undertake the above calculations, then a default value of 20 m/s should be used. 

Effective stack exit temperature 

The annual average temperature [in degrees Celsius (°C)] of the released gas when it exits the stack. If the actual temperature is not known, the facility can report the annual average stack exit temperature that was used for the purposes of obtaining a current approval or a permit, or a default value of 1,000°C can be used, or the facility can indicate that the annual average exit temperature is unknown.  

D.5 Exemptions from individual stack reporting requirements

D.5.1 Exemptions for certain types of facilities

Certain facilities in the oil and gas extraction except oil sands sector (NAICS code 211110) with fewer than ten employees are exempt from individual stack reporting requirements (“Case 3” and “Case 4” facilities). Releases from stacks and flares at these facilities still need to be reported, just not at the individual stack level.

D.5.2 Exemptions for certain sources

Stacks and vents from storage tanks that emit releases at or near ambient temperatures are exempt from individual stack reporting requirements. Releases from these tanks still need to be reported, just not at the individual stack level.

D.5.3 Exemptions based on stack characteristics

The following types of stacks are exempted from individual stack reporting requirements: horizontal or non-vertical stacks (e.g., gooseneck shape), and vertical stacks with rain caps. Releases from these stacks must still be reported as part of stack or point releases, but do not need to be reported separately at the individual stack level.

D.6 Stack grouping

Similar stacks can be reported as a group instead of individually, if certain conditions are met. If a facility has received prior permission from a regulatory authority to group stacks for air dispersion modelling for the purposes of obtaining approval or a permit (e.g., Ontario’s Environmental Compliance Approval), then the facility is allowed to report for those stacks as a group to the NPRI. If no prior permission has been obtained, ECCC will allow reporting of more than one stack as a group, provided the following conditions are met:

• the grouped stacks are ≥25 m and <50 m in height
  • stacks ≥50 m in height cannot be grouped and will continue to be reported individually
• the grouped stacks must be within 250 m of the approximate geographic centre of the group
• releases from the grouped stacks must be ±35% of the average releases from all stacks in the group
• the stack height, inside diameter, exit temperature and exit velocity must be within ±35% of the average
• total releases from the grouped “stack” are greater than or equal to the stack air release threshold

When reporting for a grouped or virtual stack:

• the stack name needs to include the word “group” and the number of stacks included in the group
• the average height, inside diameter, and exit temperature and velocity need to be reported for the group
• the geographic coordinates of the approximate centre of the group must be reported
• a list of the stacks in each group, and information on their characteristics, provincial identification numbers and latitude and longitude need to be provided to ECCC (by email to inrp-npri@ec.gc.ca)
• total releases from each grouped “stack” would be reported through the reporting software or bulk upload

Appendix E - supplemental information on volatile organic compounds

Table 20 shows the substances that are listed in Part 5, along with the synonyms and common names of those substances, where applicable. Where more than one CAS RN applies, Table 20 also lists the names and CAS RNs that must be reported. These CAS RNs are for information only and do not necessarily include all the CAS RNs that may apply to the group or mixture. Also note that isomers of the listed substances may exist in mixtures of isomers, and the CAS RNs of these mixtures of isomers may not necessarily be listed in Table 20.

Appendix  F - Individual CAS RNs of new substance groupings added to Part 1B of the NPRI substance list for 2025-2027