Donlin Gold is committed to protecting the environment in the Yukon-Kuskokwim (Y-K) region. Our environmental plan encompasses virtually every aspect of the Donlin Gold project and is discussed throughout this website.

For 21 years, Donlin Gold has been conducting a wide range of environmental studies to evaluate the possible impacts of the activity required to construct and operate the mine.

Resources and topics in the baseline-study program include:

• Air quality
• Cultural resources
• Fish and aquatic resources
• Geochemistry
• Geotechnical
• Hydrology/Ground and surface water quality and quantity
• Land use
• Marine and river
• Mercury
• Noise
• Public health
• Recreation
• Snow surveys
• Socioeconomics
• Stream and sediment
• Subsistence
• Vegetation
• Visual aesthetics
• Wetlands
• Wildlife

Data from these studies is being used in the design process so the mine can meet or exceed environmental standards, in addition to the protection of the natural and subsistence resources in the Y-K region. The data will also provide information about the environment before, during and after mine operations to ensure the land is continuously protected.

These studies will be submitted to regulatory agencies during the permitting process.

We are continually refining our mine plan and daily activities based on the feedback we receive from the Yukon-Kuskokwim community. From long-term engineering to everyday worksite behavior, we routinely go above and beyond safety standards required by state and federal government agencies.

Cyanide has been used in the mining industry for well over 100 years and, with proper management, can be used safely and without harm to the environment. In modern times, there have been significant scientific advances in the use of chemical and biological reactions to convert cyanide to less-toxic chemicals.

Gold cyanidation, a process in which gold is temporarily converted into a water-soluble form, is the most widely accepted method for efficient and environmentally sound gold extraction.

Donlin Gold plans to use this practice to extract the gold from the ore, and will follow guidelines provided by the International Cyanide Management Code on how to handle cyanide from its manufacturer to its transport, storage, use and disposal.

Dry sodium-cyanide briquettes will be shipped to the mine site in sealed steel ISO (International Standard Organization) tanks that are waterproof and can float. The cyanide will be dissolved into a weak, pH-controlled solution for use in gold extraction. After the ore is crushed into smaller-sized grains, it will be transported to an on-site leaching plant, where the ore will be mixed with cyanide. The cyanide will dissolve the gold into a solution, then the gold will be precipitated out of the solution.

The cyanide solution will go through a destruction process that reduces its concentration. This industry-leading detoxification process has been adopted in the last 25 years by major gold-mining companies worldwide. The trace amounts of cyanide remaining in the tailings-storage facility will disintegrate further under the influence of sunlight and air.

One of the most important elements of the Y-K region is the Kuskokwim River. We understand the importance of this river to the people, fish and animals of the region. By closely studying the river, we can adapt our activities to best protect it.

Studies of the Kuskokwim River include:

• Fishing activity and river-use surveys from Georgetown to Kuskokwim Bay
• Erosion studies
• Barge-wake-impact studies
• Sediment and water sampling
• Noise observations
• Wildlife observations

Mining is a relatively minor source of mercury air emissions both nationally and globally.

Most of the rock in the area surrounding the Donlin Gold project has naturally occurring mercury, which is typical of an area associated with volcanic activity, high-heat flows and plate-tectonic boundaries.

This mercury is released into the atmosphere through natural processes, such as weathering of rock, vaporization from soil, wildfires and off-gassing of the world’s oceans. According to the U.S. Environmental Protection Agency (EPA) and other scientific sources, about one-half of the mercury emitted into the air each year is from these natural processes.

The primary source of human-generated mercury air emissions is the combustion of coal. Once released into the atmosphere, mercury may be transported great distances from its original source. For example, according to the EPA, half of the human-generated mercury that is deposited in the western U.S. comes from industrial sources in Asia.

In 2010, the EPA finalized national emissions standards for mercury based on maximum achievable control technology (MACT).  These new limits are based on the nation’s best-performing gold-processing facilities, which are well-controlled for mercury. To adhere to these new EPA regulations, Donlin Gold is committed to installing and operating state-of-the-art mercury-emissions controls to meet or exceed these standards.

The Y-K region has an abundant supply of fresh surface water, with about 20 inches of annual precipitation at the project site. Donlin Gold is committed to protecting local water sources from pollution and has been conducting surface-water-quality monitoring and groundwater-quality monitoring as part of the baseline studies for the project for over a decade.

Any water that comes in contact with the mine, such as rainwater or snowmelt, would be diverted into a contact-water pond. The pond would be used to supply water for the mill. A freshwater reservoir could also provide an additional supply of water for processing, as well as other emergencies and unexpected situations, like fires.

Before any water is discharged into the environment, it will be treated to meet strict water-quality standards. Donlin Gold is also looking at different methods of recycling water to help reduce water use.