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Guidance for the Reporting of Tailings and Waste Rock to the National Pollutant Release Inventory (NPRI)

Reporting to the NPRI

Appendix 4 provides a step-by-step approach summarizing the following information.

The owner or operator of the facility as of December 31, 2009 is required to report for 2006 to 2008 years, and for 2009. If the facility closed during that period, the last owner or operator of the facility is required to report.

1. 2006-2008 reporting

The 2006-2008 Canada Gazette (CG) notice is applicable to facilities from the bitumen, coal, diamonds, metals, and potash sectors that generated or disposed of tailings and/or waste rock during those years. A facility is subject to the 2006-2008 CG notice if, during one or more of the 2006-2008 calendar years:

  • employees at the facility worked 20 000 hours or more; and
  • the facility generated or disposed of tailings or waste rock as a result of the extraction or recovery of bitumen, coal, diamonds, metals or potash, or the extraction or beneficiation of metallic ore or ore concentrate.

2. 2009 reporting

For 2009 all facilities are subject to the tailings and waste rock requirements. If a facility from any sector disposes of tailings or waste rock, they must report on this disposal if they meet the applicable reporting criteria. Sectors that dispose of tailings and waste rock may include, but are not limited to, such sectors as coal, diamonds, potash, oil sands, metals, which include copper, nickel, lead, zinc, gold, silver, iron ore, and uranium, quarries, industrial minerals, and other applicable non-mining sectors.

In order to report the relevant information to the NPRI, Appendix 1 has been included to facilitate the reporting of tailings and waste rock for 2006-2008 and 2009. This Appendix specifically provides the key highlights per each CG notice as well as a relative comparison of the differences between the two notices regarding the reporting of tailings and waste rock. Figure 3 below summarises the reportable, and non-reportable mine materials to assist reporter in their duties.

3. Substances

For 2006-2008, the reporting of substances found in tailings and waste rock only applies to substances in Part 1 and Part 2 of Schedule 1 of the notice.

For 2009, reporting of substances disposed of to tailings and waste rock management areas applies only for substances in Parts 1, 2 and 3 of Schedule 1 of the notice.

Complete lists of NPRI substances for 2006-2008 and 2009 regarding the reporting of tailings and waste rock are provided in Appendices 2 and 3, respectively.

4. Exclusions

The key areas of exclusions related to tailings and waste rock are outlined under the sections below.

Under the Reporting Requirements section, quantities that are excluded from the mass reporting thresholds are also excluded from being reported to the NPRI. 

The following exclusions only apply to substances contained in the materials below. Once the substance is released to air or surface waters from the materials below (for example, dust released while moving overburden and leaching of metals from tailings or waste rock), the quantity of the substance released must then be included in the threshold calculations and reported to the NPRI if applicable.

Figure 3 – Diagram of reportable and non-reportable mine materials

Figure 3 – Diagram of Reportable and Non-reportable Mine Materials

i. Overburden

This material is excluded from threshold calculations and reporting.  See definition of overburden in section 3 of this Guide.

ii. Stable/ inert constituents of tailings

Since these materials are expected to be stable/ inert, and have not been altered during the ore processing, they are not included in threshold calculations or reported values, provided that they meets the following conditions:

  •   Only inert, inorganic components are excluded
  •   The component must not have been reduced in size or otherwise physically or chemically altered.

This applies only to the components of tailings that meet the criteria (i.e., if part of the tailings stream met the criteria, only that portion of the tailings would be excluded and the other components would be required to be included).

In summary, certain materials in tailings that are inert, inorganic and have not been crushed or otherwise physically or chemically altered, are excluded from threshold calculations and reporting (e.g. sand grains from bitumen mines or in-situ production of bitumen).

iii. Waste rock

In some cases, in particular for the uranium industry, mining operations have operating permits that classify the waste rock generated by that facility. Where a valid operating permit specifically identifies waste rock that is considered inert (or clean, the term generally used in the mining industry), the NPRI substances found in that waste rock is to be excluded from threshold calculations and reporting.

Where there is not a valid operating permit that specifies that waste rock is considered inert, the exclusion is based on following criteria in terms of sulphur and arsenic content, and acid generating potential.

  • Acid generating potential: Waste rock is to be excluded if it has a sulphur content of less than or equal to 0.2 percent, or if it has a higher sulphur content but the ratio of neutralizing potential to acid generating potential is greater than or equal to 3:1.
  • Arsenic content: Since the release of arsenic is not necessarily linked to acid generation potential, the quantity of arsenic in waste rock must be included where the concentration of arsenic in the waste rock is greater than 12 mg of arsenic per kg of waste rock, even if the waste rock would be excluded for other substances based on the criteria related to acid generating potential.
  • Where a quantity of an NPRI substance in waste rock is excluded based on these factors, the facility would be required to provide adequate information on the permit or other data on which the exclusion was based.

Note: If NPRI substances are released from waste rock that is excluded based on the criteria above, the quantities of NPRI substances released must then be included.

Please refer to the waste rock sampling techniques documents as referenced in the Reference and Bibliography section.

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