On January 6, the U.S. Army Corps of Engineers published a notification that the permit application submitted by the Pebble Ltd. Partnership, owned by Northern Dynasty Minerals, had been accepted. This formally begins the permitting process under the National Environmental Policy Act (NEPA) review process and other permitting efforts associated with the project to develop the copper-gold-molybdenum porphyry deposit in southwest Alaska as an open-pit mine. The company’s application incorporates more than a decade of third-party environmental research.
Pebble Partnership CEO Tom Collier said the Pebble team has redesigned the project in response to stakeholder concerns. The development proposed is substantially smaller than previous iterations, and presents significant new environmental safeguards, including a development footprint less than half the size previously envisaged; the consolidation of most major site infrastructure in a single drainage (the North Fork Koktuli), and the absence of any primary mine operations in the Upper Talarik drainage; a more conservative Tailings Storage Facility (TSF) design, including enhanced buttresses, flatter slope angles and an improved factor of safety; separation of potentially acid generating (PAG) tailings from non-PAG bulk tailings for storage in a fully-lined TSF; no permanent waste rock piles; and no cyanide usage.
“These are very substantial improvements that we have made over the past few years in response to issues and concerns raised by project stakeholders,” Collier said. “We believe that as Alaskans become more familiar with our proposed project design and the environmental safeguards it incorporates, there will be an increasing degree of support for the project, and the significant economic potential it represents for the state of Alaska.”
Following four years of construction activity, the proposed Pebble mine will operate for a period of 20 years. This includes 14 years of mining using conventional drill-blast-shovel operations, followed by six years of milling material from a low-grade ore stockpile. The mining rate will average 90 million tons per year, with 58 million tons of mineralized material going through the mill each year, for an extremely low life-of-mine waste to ore ratio of 0.1:1.