Frequently asked questions: National Pollutant Release Inventory


What is the National Pollutant Release Inventory (NPRI) and why is it needed?

The National Pollutant Release Inventory (NPRI) is Canada's legislated, publicly accessible inventory of pollutant releases and transfers. It comprises information reported by facilities to Environment Canada under the Canadian Environmental Protection Act(CEPA), together with air pollutant emission estimates compiled for facilities not required to report and non-industrial sources such as motor vehicles, residential heating, forest fires and agriculture.

The NPRI is at the centre of the Government of Canada's efforts to track toxic substances and other substances of concern. It is a key tool for identifying and monitoring sources of pollution in Canada, as well as for developing indicators for the quality of our air, water and land. Information collected through the NPRI is used for chemicals management initiatives and it is made publicly available to Canadians each year. Public access to the NPRI motivates industry to prevent and reduce pollutant releases. NPRI data helps the Government of Canada to track progress in pollution prevention, evaluate releases and transfers of substances of concern, identify and take action on environmental priorities, conduct air quality modelling, and implement policy initiatives and risk management measures.

The NPRI is one of many pollutant release and transfer registers (PRTRs) around the world. The United States Toxics Release Inventory and Australia's National Pollutant Inventory are other such registers. The first report by Canada's National Pollutant Release Inventory was released in 1995 and contained pollutant release and transfer information reported for 1993.

Who needs to report to the NPRI and how are the NPRI reporting requirements developed?

Under the authority of Canadian Environmental Protection Act 1999 (CEPA 1999), owners or operators of facilities that manufacture, process or otherwise use or release one or more of the substances tracked by the NPRI and meet reporting thresholds and other requirements are required to report their pollutant releases, disposals and transfers for recycling annually to the NPRI. For more detailed information on NPRI reporting requirements, consult the NPRI Reporting Tools and Guidance.

Proposed changes to the NPRI undergo public consultation. After considering stakeholder feedback, Environment Canada decides on changes to the NPRI. All changes are published in Part I of the Canada Gazette. Any person, government or organization in Canada can submit proposals for changes to the NPRI program to Environment Canada. The consultation process involves roundtable discussions among a multi-stakeholder group, including representatives from federal and provincial/territorial governments, industry, non-governmental organizations and Aboriginal groups. For information on how to propose changes to the NPRI program, please visit the NPRI Consultations Web page.

Is reporting to the NPRI voluntary or mandatory?

Reporting to the NPRI is mandatory. Under the authority of the Canadian Environmental Protection Act, 1999 (CEPA 1999), owners or operators of facilities that meet published reporting requirements are required to report to the NPRI. It is the obligation of the person who owns or operates the facility to review NPRI reporting criteria annually, as the criteria are subject to change. Facilities reporting after the prescribed deadline (typically June 1st) or knowingly providing false or misleading information are in violation of CEPA 1999. These facilities will be referred to enforcement staff for review and possible enforcement action.

What information is collected through the NPRI?

All facilities that meet National Pollutant Release Inventory (NPRI) reporting requirements must report releases, disposals and transfers of substances tracked by the NPRI. Information on pollution prevention activities and facility information, such as location, industry classification and the number of employees, is also reported to the NPRI. For each facility and substance, data users can find out where and to what media (air, water or land) the substance was released. The information also includes how and where the substance was disposed of, treated or recycled.

Release, disposal, and transfer categories reportable to the NPRI

There are a number of categories for reporting of releases, disposals and recycling to the NPRI. On-site releases include releases to air, water, and land. Releases to air include stack or point releases, storage or handling releases, fugitive releases, spills, road dust, and other non-point source releases. Releases to surface waters include direct discharges, spills, and leaks. Releases to land include surface and underground releases from spills, leaks, and other releases to land that are not disposals. On-site disposals include landfills, land application, underground injection, and tailings and waste rock. Off-site disposals include total quantities transferred off the facility site for final disposal in landfills, land application, underground injection, storage off-site prior to final disposal, and tailings and waste rock. Off-site transfers for treatment prior to final disposal include types of physical, chemical, biological or thermal treatment and treatment in municipal sewage treatment plants. Off-site transfers for recycling and energy recovery refers to the recovery of solvents, organic substances, metals and metal compounds, inorganic materials, acids or bases, catalysts, pollution abatement residues, or the refining or reuse of used oil.

How many facilities report to the NPRI?

Each year, approximately 8,000 industrial, commercial and other facilities report to the NPRI on their releases, disposals and transfers for recycling of listed toxic substances and other substances of concern. Air pollutant emission estimates for other facilities and non-industrial sources are compiled for criteria air contaminants (the principal pollutants contributing to smog, acid rain and/or poor air quality), selected heavy metals and persistent organic pollutants.

How are NPRI data collected from facilities?

Facilities report their pollutant release and transfer data through Environment Canada's Single Window (SW) reporting system. SW is an online reporting tool used by Environment Canada, some provincial governments and industry associations to collect environmental data from industry. The tool was developed in response to stakeholder requests to streamline and simplify reporting efforts.

What are the "Air Pollutant Emission Summaries and Trends" and how are they compiled?

See the Air Pollutant Emission Inventory home page for more details.

How does Environment Canada ensure the quality of NPRI data?

An overview of NPRI data quality measures and procedures is available in the NPRI "Data Quality Assurance" section.

How are NPRI data used?

Data from the NPRI can be used in many ways by many different organizations and groups.

  • Data analysts (e.g., scientists, policy analysts, and academic researchers) use NPRI data to conduct research on environmental issues such as the impacts of pollutant releases on the environment and human health.
  • Companies use NPRI data to report on corporate environmental performance and to compare their pollutant releases with others in their sector.
  • Industry associations use NPRI data to research sectoral environmental issues and to evaluate the performance of member facilities.
  • Non-governmental organizations use NPRI data to promote understanding of pollution issues and to influence public policy and corporate environmental management.
  • Aboriginal groups use NPRI data to understand and report on the impact of pollutant releases and transfers on their communities.
  • Governments
    • Federal officials use NPRI data to track the progress of pollution prevention efforts, identify sectoral concerns, and to support air quality modelling and chemical risk assessment and management initiatives.
    • Provincial governments use the data to develop provincial emissions inventories and environmental indicators and to track progress of facilities within their jurisdictions.
    • Municipal officials use pollution data to conduct environmental sustainability planning and to research local air and water quality concerns.
  • Individuals and community groups use NPRI data to obtain information on pollutant releases and transfers from facilities near their homes, workplaces and schools and to engage these facilities in pollution prevention.
  • Finance sector firms use pollution data to assess the growth potential for environmental services and technologies (e.g., waste management and emission control), to research companies for environmentally friendly mutual funds and to report on environmental performance to investors.
  • Academics and students use NPRI data to research pollution issues and to develop project or course content.
  • The media use NPRI data to report on local, regional and national pollution issues and trends.
What factors need to be considered when analyzing National Pollutant Release Inventory (NPRI) data?
Does the NPRI include information on all pollutants and all pollution sources?

The NPRI is a key tool for identifying and monitoring sources of pollution in Canada, but it does not have information on all pollutants or every pollution source in the country.

The NPRI collects information from industrial, commercial, institutional and other facilities that meet certain reporting requirements and for a given list of substances. These reporting requirements are based on the number of employees, the quantity of the substance(s) manufactured, processed, used or released and the type of activities performed at the facility.

For more information, see the Guide for Using and Interpreting NPRI Data.

How can NPRI data be accessed?

The NPRI Online Data Search allows users to access information about substances released, disposed of, or transferred for recycling by facilities in Canada. Alternatively, users can download the NPRI database, in Microsoft Access format or Excel format.

NPRI data are also available in downloadable .kmz format files for use with Google Earth™. These NPRI Google Earth™ Map Layers files can be used to view NPRI facility locations and their release, disposal and recycling information for the latest reporting year.

The annual Air Pollutant Emission summaries and trends are available in HTML and Excel format.

When are NPRI data published?

Preliminary data reported by facilities to the NPRI data are typically published in the On-line Data Search within one month of the annual reporting deadline. Environment Canada staff then review the data for possible inaccuracies and verify information with facilities as necessary. Following this analysis, Environment Canada typically publishes a reviewed dataset in various formats within six months of the annual reporting deadline.

Updated Air Pollutant Emissions Summaries, based on data reported by facilities as well as emission estimates for other sources, are published each spring.

Tailings and waste rock

What are tailings and waste rock?

“Tailings” are the waste material that remains after the processing of ore, ore concentrate or other mined materials (i.e. oil sands) to extract marketable components such as metals, minerals or bitumen. Depending on the type of process used and the material being recovered, tailings could include finely ground rock material, sand, clay, water, chemicals used in the process, or residual metals, minerals or bitumen.

“Waste rock” is rock which is removed during the mining extraction operations to provide access to the ore, and is not further processed at that time. Waste rock generally consists of fragmented pieces of rock of various sizes. 

Why did Environment Canada put in place reporting requirements for tailings and waste rock?

The reporting requirements for tailings and waste rock resulted from a judicial review of the NPRI program.

Mines were required to report their direct releases to air, water and land before the tailings and waste rock reporting requirements were put in place. The requirements help provide more comprehensive information on substances of concern in Canada.

Why are the substances contained in tailings and waste rock of potential environmental concern?

The NPRI-listed substances contained in tailings and waste rock generally occur naturally in the rock or bitumen deposits removed during mine operations, typically in low concentrations. However, overall quantities can be large due to the volume of materials removed or processed. Furthermore, while tailings and waste rock in Canada are managed to reduce the risk of environmental contamination, concerns remain due to acidic drainage, potential leakage from tailings ponds and the possibility of wildlife contact with the tailings. The Government of Canada and industry are actively working to manage these potential risks.

What do facilities have to report under the tailings and waste rock (TWR) requirements?

In addition to direct releases to air, water and land, facilities that meet reporting requirements must also report the quantity and concentration of NPRI substances disposed of in tailings or waste rock management areas on-site, or sent to another facility for disposal in such areas.

For more information on NPRI reporting requirements for tailings and waste rock, please see the Guide for the Reporting of Tailings and Waste Rock to the NPRI.

What types of facilities report under the tailings and waste rock (TWR) requirements?

There are different requirements for 2006-2008, and for 2009 and future years:

For 2006-2008: The requirements apply only to mining and oil sands facilities that generated or disposed of tailings and/or waste rock from the extraction or processing of bitumen, coal, diamonds, potash or metals; and had the equivalent of 10 or more full-time employees.

For 2009 onward: The requirements apply broadly to all facilities that generated or disposed of tailings and waste rock and meet reporting thresholds.

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