A new US Environmental Protection Agency (EPA) report shows that the metal mining industry managed to slash total substance or chemical disposals or releases by the most of all US industries for calendar year 2004. The EPA’s latest Toxics Release Inventory Report (TRI), released April 12, found that 2004 disposals and releases from metal mines dropped by 168 Mlb, marking a 14% reduction over 2003 levels. In total, metal mines accounted for just 2% of all reported 2004 air and surface water releases.

Part of the report noted the continuing reductions in mercury air emissions Nevada gold mines have accomplished using a voluntary emissions reduction programme. This marks the second consecutive year in which Nevada gold mines have been able to report mercury air emission reductions resulting from their participation in the Nevada Department of Environmental Protection’s Voluntary Mercury Reduction Program. Mercury is not used in the gold mining process, but occurs naturally in soils at some mine sites and is, therefore, a co-product of some mines’ ore.

By volume, more than 98% of the trace releases reported to EPA by mining operations involve substances that occur naturally in the local rock and soil. These substances are generally low in concentration within the large amount of material handled and managed at specially designed mine site facilities. Because these trace amounts are covered by TRI, mining operations not surprisingly constitute more than half of the TRI releases to land for on-site management that were reported by all operations for 2004.

Variations in the report regarding year-to-year TRI reporting for individual mining facilities are most often the result of changes in the amount of ore mined that year and the level of natural mineralization of the orebody.

The TRI programme is a weight-based report and is not intended to evaluate risk. This is the seventh year mining operators have reported under the programme. Data and background information from this year’s report can be found at: www.epa.gov/tri/tridata/tri04/index.htm.