Section 2: Metal Mining

Waste Management by Metal Mines

As shown in this figure, 95% of the metal mining sector’s production-related waste managed is disposed of or otherwise released. While metal mining production (as reported in the U.S. Geological Survey Mineral Commodities Surveys) has remained relatively steady from 2003 to 2013, as shown by the black line in the graph, the quantity of waste managed has fluctuated. This indicates that factors other than production have contributed to the recent changes in quantities of waste managed. One factor frequently cited by facilities is the composition of the extracted ore and waste rock, which can vary substantially from year to year. In some cases, small changes in the waste’s composition can impact whether chemicals in waste rock qualify for a concentration-based exemption. When present at very low concentrations, toxic chemicals in waste rock may qualify for the exemption and not need to be reported in one year, but not qualify for the exemption the next year or vice versa.

In the metal mining sector, 9 of the 88 facilities initiated source reduction activities in 2013 to reduce their toxic chemical use and waste generation. Toxic chemical quantities reported by this sector are not especially amenable to source reduction, because they primarily reflect the natural composition of the ore and waste rock. The most commonly reported source reduction activity was improving maintenance scheduling, record keeping, or procedures.

To learn more about this sector, visit EPA’s website on reducing pollution from mineral processing operations.

This page was published in January 2015 and uses the 2013 TRI National Analysis dataset made public in TRI Explorer in October 2014.