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2015 Summary Report: Reviewed Facility-Reported Data

2. General Considerations When Using NPRI Data

The current report was prepared using data submitted by facilities as of September 29, 2016, for the 2015 reporting year. Following quality control checks of facility-reported data, a number of potential reporting errors by facilities were identified, and these were prioritized for follow-up. A number of facilities proceeded to update their reports as a result. This data also contains updates and new reports submitted by facilities for 2014 and previous reporting years.2

NPRI facility data are available in multiple formats, including an online data search application, map layers for use with Google EarthTM and downloadable datasets.  For access to the data in electronic format and other information about the NPRI, please visit the NPRI website and the Government of Canada Open Data Portal.

The NPRI makes a significant amount of data available to data users, and this data can be analyzed in a number of ways (e.g. by substance, by facility, by media [air, water, land], by geographic region, by industrial classification code and/or by type of release to the environment [direct releases, disposals, transfers]). Appendix 1 of this report provides a breakdown of the 2015 facility reported data by substance and by substance category. NPRI data can also be combined with other data sources, such as monitoring data collected under other programs, to provide a more comprehensive picture of pollution in various areas of the Canadian environment.

There are considerations to be taken into account by data users to ensure NPRI data are analyzed and interpreted properly.

The NPRI is designed to track the largest sources of pollution from industrial, commercial, and institutional facilities. Not all sources of pollution in Canada are reported through the NPRI. The NPRI requires that facilities that meet certain reporting criteria report their releases, as applicable, of more than 300 substances (which are indicated on a regularly updated list). Small facilities, facilities undertaking certain activities, and facilities operating in certain sectors are exempt from reporting.

Data users should also note that NPRI substances do not all pose the same potential risk to the environment and to human health. This variation in the properties of different substances should be taken into account when processing (e.g. adding) NPRI data concerning different substances. The purpose of providing totals in this report is to offer a general perspective on pollutant releases, and not to characterize the impacts of this pollution.

Data users should also be aware of the possibility of double counting when adding NPRI substances from different facilities or from different parts of the NPRI reporting requirements. For example, certain substances (certain sulphur compounds, certain particulate matter fractions, certain aromatic hydrocarbons, etc.) must be reported under more than one NPRI reporting requirement. Consequently, these quantities are reported several times, and should not be added.

It is also necessary to take into account changes made to NPRI reporting requirements over time. Figure 2-1 illustrates how some of the changes made to the reporting requirements have had an impact on the number of facilities reporting to the NPRI over the years as well as on the list of reported substances. Other factors that impact the number of facilities reporting to the NPRI include the closure of facilities, or facilities no longer meeting reporting thresholds due to changes in production levels or production processes.

Figure 2-1Changes to NPRI reporting requirements, 1993-2015

Two line diagram showing the evolution, since 1993, of the substances part of the NPRI and the number of facilities reporting to the program

Long Description
YearNumber of substancesNumber of facilities


  • 1993
    • NPRI started in 1993 with 178 substances
    • 1,388 facilities reported the first year
  • 1999
    • 73 substances added
  • 2000
    • 17 polycyclic aromatic hydrocarbons, dioxins, furans and hexachlorobenzene added
  • 2002
    • 7 criteria air contaminants added, almost doubling the number of facilities required to report
  • 2003
    • 60 speciated volatile organic compounds added
    • Oil and gas facilities added, again almost doubling the number of facilities required to report
  • 2006
    • Mining extractions and crushing, 3 polycyclic aromatic hydrocarbons and 15 speciated volatile organic compounds added
  • 2007
    • Total reduced sulphur, 9 polycyclic aromatic hydrocarbons, and 17 dioxins and furans added
  • 2014
    • Thallium and 2-(2-methoxyethoxy)ethanol added, 5 substances deleted

When conducting analyses over time or comparing facilities, possible changes involving the facility must be taken into consideration. Important factors can include changes in production levels, changes in the calculation methods used to quantify releases, the implementation of pollution prevention activities, or subsequent updates of the data submitted to the NPRI for previous years.

Finally, despite all the efforts made by NPRI reporting facilities, errors sometimes occur when submitting information to the NPRI. Environment and Climate Change Canada implements a number of measures to ensure the relevance, accuracy, reliability, completeness, understandability, accessibility, and timeliness of NPRI data in order to continue to meet the needs of data users. For more information, please consult the data quality page of the NPRI website.

For more information about the factors to consider when using and interpreting NPRI data, please refer to the Guide for Using and Interpreting National Pollutant Release Inventory (NPRI) Data.

For more information on the assumptions and specific considerations used in preparing the NPRI Summary Report for 2015, please refer to the Technical Notes in section 9 of this Report.


Footnote 2

It should be noted that the NPRI reporting system is available year-round and that facilities can submit reports or corrected data at any time, regardless of the reporting year. More than 550 facilities submitted an update or a report for 2014 in the months following the publication of the NPRI summary report for 2014.

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