Donlin Gold reports that the State of Alaska has reaffirmed the 401 Clean Water Certificate

Donlin Gold would like to report that the Alaska Department of Environmental Conservation (ADEC) has reaffirmed Donlin Gold’s Clean Water Act 401 Certificate of Reasonable Assurance (401 Certificate). The 401 Certification indicates the State’s reasonable assurance that issuance of the Federal Clean Water Act Section 404 permit will not cause exceedances of the State’s water quality standards. This final decision is part of the ongoing appeal filed by Earthjustice and Orutsararmiut Native Council.

Donlin Gold submitted two scientific reports in October of 2021 to the ADEC. The reports include additional scientific data collected during the summer of 2021 and an analysis of the project’s potential effects to water quality, in particular mercury and temperature. These topics are important to the residents of the region along with Donlin Gold and our partners and merit the added in-depth look. Mercury and temperature effects have been key topics in the ongoing appeal of the 401 Certificate.

The reports conclude that:

• The concentration of mercury in Crooked Creek would stay essentially the same as existing levels or potentially decrease (i.e., improve).

• Predicted streamflow reductions in Crooked Creek would not cause water temperatures to exceed the Alaska Water Quality Standards.

Furthermore, Donlin Gold has revised the mine’s Monitoring Plan to include additional monitoring for mercury and temperature in Crooked Creek surface waters.

ADEC has repeatedly upheld its decision to issue the 401 Certificate for the Donlin Gold project. “We believe the additional studies provided compelling support for the 401 Certificate. The two studies extend the already large body of scientific information about water quality in Crooked Creek, ensuring that the healthy ecosystem upon which people depend is protected. The additional water quality monitoring provides further assurance the project will comply with Alaska’s strict water quality standards. ADEC’s decision to reaffirm the 401 Certificate, after completing their own independent review, further confirms this. The reissuance of the 401 Certificate is even more strongly supported by this added data and analysis, and monitoring. We would like to thank the ADEC for the additional and thorough work in the updated 401 Certificate. Donlin Gold is committed to responsible development of the mineral resources owned by Calista Corporation, the Alaska Native Corporation for the Yukon-Kuskokwim region of western Alaska, and the associated benefits it can bring to the shareholders and residents of the region,” said Dan Graham, General Manager at Donlin Gold.