EPA Mercury Air Emissions from Gold Mines Rulemaking

The Environmental Protection Agency (EPA) recently announced a proposed rule limiting mercury air emissions from gold mines. This rule would apply to the Donlin Creek Mine, but the rule does not go far enough to protect people and the environment.

Mercury is a naturally occurring metal and is often found in a rock called "cinnabar." This rock was historically mined along the Kuskokwim River, and mercury was in mining waste and continues to be released into the environment from these old mines. The Donlin Creek Project is located in the "mercury belt" of Alaska, a geologic zone of Alaska where mercury is found in many rock formations. As a result, mining and milling activities at the mine will produce both point source and fugitive source mercury emissions.

EPA's proposed rule will regulate the amount of mercury air emissions from point sources at mines-stacks and vents. As it is proposed, the rule would limit emissions for pre-treatment processes (roasters and autoclaves) to 149 lb/ton of ore processed at both new and existing mines. The Donlin Creek Mine intends to process 22 million tons of ore per year. That means that under the proposed rule, Donlin Creek could be permitted to emit over 3200 pounds of mercury per year, just from pre-treatment processes.

Additionally, the rule limits mercury emissions for carbon concentrate processes to 2.6 lb/ton of concentrate for existing mines and 0.14 lb/tons of concentrate or a 97% reduction in uncontrolled emissions for new mines. This will allow the Donlin Creek Mine to emit additional mercury. Further, the rule does not limit emissions from fugitive sources at the mine-waste rock piles and tailings ponds. Thus, the total mercury air emissions from the mine will be even higher. 

For comparison, 2008 Toxic Release Inventory data from the EPA indicates that 71 pounds of mercury was emitted into the air in Alaska that year. This means that under the proposed rule, the Donlin Creek Mine would increase mercury air emissions in Alaska more than 40 times.

Additionally, the proposed rule only requires annual monitoring; monitoring needs to be more frequent.

• To learn more about the proposed rule, visit EPA's Mercury page by clicking here. 

• To download the proposed rule, click here [229 KB].

• To learn more about the Doniln Creek Project, click here.

• To download the folio "Mercury, the Donlin Creek Mine Project and What it Means for the Kuskokwim River," click here. [701 KB]
• Click here to visit Ground Truth Trekking's site and for a larger version of the mercury cycle graphic above.