In 2011, the United States Environmental Protection Agency (EPA) promulgated National Emissions Standards for Hazardous Air Pollutants (NESHAP) for gold ore processing and production facilities. This rule is set forth in Volume 40 of the Code of Federal Regulations (CFR) Part 63 Subpart EEEEEEE (40 CFR 63 Subpart EEEEEEE). These gold ore processing and production facilities are required to obtain a federal permit under 40 CFR part 70 or 40 CFR part 71 (Title V operating permit), even if they are not associated with a major source.
For centuries, humans used mercury to extract gold or silver. Incredibly dangerous if inhaled directly, mercury also poses an environmental burden when it is released into the atmosphere or ends up in water. Mercury release can have natural (from volcanoes and forest fires) or man-made (anthropogenic) origins (power plants and manufacturing). One anthropogenic source linked to Air Sciences’ work is gold mining in Nevada.