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Toxics Release Inventory (TRI) Program

Explore a Metal Mine that Reports to the TRI Program

This graphic, developed with input from the mining industry, shows an example (fictional) metal mining facility that reports to the Toxics Release Inventory Program. Text in the numbered pop-up boxes describes how and where TRI-listed chemicals are used, managed, and released into the environment.

EPA developed this graphic to provide users of TRI data with a better understanding of mining operations and related TRI-reportable chemical releases. The metal mining sector handles large volumes of material and each year, this sector reports the largest total quantity of releases of TRI-covered chemicals (mostly in the form of waste rock) of any industry sector covered by the TRI Program. Consequently, this sector greatly influences the TRI data viewed by the public, driving several important national and local trends. For these reasons, EPA is explaining the metal mining sector’s TRI data in more detail. In the future, EPA may profile other important TRI industry sectors.

To start, click on any of the numbers in the graphic. You can also see a text-only version of the interactive content on this page. 

Also on this page:

BlastingOre RemovalOre TransportationWaste RockGrinding and CrushingConcentratorLeach PileMetals RecoveryTailings Treatment PondProduct
Facility Basemap

BlastingOre RemovalOre TransportationWaste RockGrinding and CrushingConcentratorLeach PileMetals RecoveryTailings Treatment PondProduct

Summary of the Metal Mining Sector and TRI Reporting

Most of the quantities of TRI chemicals reported by metal mining facilities are, by far, on-site disposals to land (see steps 4, 7, 8 and 9 for example), though TRI chemicals are also released on site to air and water and are transferred to off-site disposal locations as well. For example, air releases of TRI chemicals occur in the form of fugitive emissions (such as chemicals in dust created on site) (see steps 1, 2, 3, 4, 6 and 8 for example) and stack emissions (such as chemicals in collected dust that passes through an air pollution control device) (see steps 5, 6 and 8 for example). A metal mining facility reports on TRI chemicals (for example, metal compounds) in rock and ore that it manages as waste on site, as well as on TRI chemicals related to mining operations such as extracting, processing, and refining target metals. When applicable, a metal mining facility must also report on-site waste treatment, recycling and energy recovery as well as transfers off site for waste treatment, disposal, recycling, and energy recovery.

Notes About Using This Webpage

  • The operations depicted in this graphic are intended to be illustrative of various practices of metal mining facilities across the United States, but not all of the practices depicted take place at every metal mining facility.
  • This graphic does not attempt to describe all types of releases or other waste management practices, TRI-reportable or otherwise, that may take place at any given metal mining facility. Similarly, the types of releases noted as being associated with a mining operation, as well as the way they are said to be reported, are only examples. Nor does this graphic address potential exposure to releases of chemicals.  
  • TRI reporting exemptions are not described here, but in some instances, may be applicable at metal mining facilities. This graphic and accompanying text do not present any official EPA interpretations of TRI requirements. This material cannot be used by facilities as guidance for compliance with TRI-related regulations.
  • In addition to TRI reporting requirements, federal and state regulatory controls apply to many of the TRI-listed chemicals reported, which this graphic does not address in detail.

Limitations of TRI Data in Determining Potential Risk

Please note that TRI data alone cannot reveal the degree to which the public is exposed to listed chemicals. The presence of a chemical in the environment must be evaluated along with the potential and actual exposures and the route of exposures, the chemical’s fate in the environment and other factors before any statements can be made about potential risks associated with the chemical or a release, none of which are addressed by this graphic. However, TRI data can, in conjunction with other information, be used as a starting point in evaluating such exposures and the risks posed by such exposures. EPA recommends that users of TRI data consult EPA’s guidance on “Factors to Consider When Using Toxics Release Inventory Data” for further information.  Top of Page