In February 2024, the Environmental Protection Agency (EPA) revised the National Ambient Air Quality Standards for Particulate Matter (PM NAAQS)—which officially went into effect in May 2024. Specifically, the EPA updated the primary (health-based) annual standard for PM2.5 (that is, particulate matter with diameters of 2.5 micrometers and smaller) from 12 to 9 micrograms per cubic meter.
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.