Pogo Mine is an underground gold mine located about 85 miles southeast of Fairbanks. Learn more about Pogo Mine and NAEC's involvement in on-going operations.
The Pogo mine, located in the Goodpaster River Valley, began operations in 2006 with a 10 year mine life. The mine is operated by the Sumitomo Group, a Japanese company. The underground mine processed 2,550 tons of ore per day in 2009 for a total of 930,836 tons of ore for the year.
Comprising about 16,700 hectares of claims, Pogo is located on state land in the upper Goodpaster River valley, 85 miles southeast of Fairbanks and 38 miles northeast of Delta Junction (click here for map). The mine complex is situated on the Goodpaster River, pristine clear water drainage with optimal riparian and aquatic habitat. It hosts 11 fish species, among them Arctic grayling, king and chum salmon. The Goodpaster region is also within the range of the Forty-Mile Caribou herd, and has good moose, bear and wolf habitat. Very little historical placer mining occurred in the Goodpaster region, and prior to the Pogo discovery, there had been little hardrock mineral exploration. Aside from the private gravel road that services the mine, current public access to the region is by the Goodpaster Winter Trail in winter, and by boat in summer. Human habitation is limited to recreational and remote homesteads located on the lower Goodpaster.
In July of 2009, Teck Cominco sold its 40% interest in the Pogo mine to the Sumitomo Group. As a result of that transaction, the Sumitomo Group is now the sole owner of the mine, with Sumitomo Metal Mining Co., Ltd. owning an 85% stake and Sumitomo Corporation owning the remaining 15%. The mine is operated by Sumitomo Metal Mining Pogo LLC, a wholly owned subsidiary of Sumitomo Metal Mining Co. and the Sumitomo Corp.
Type of Ore & Current Production
The Pogo deposit is a gold sulfide ore body hosted in a large quartz vein system, with low-grade gold present in quartz stockworks. The mine is expected to produce 400,000 ounces of gold per year over the ten year mine life. The Pogo mill processed 2,500 tons of ore per day in 2009, for a total of 930,836 tons in 2009. Pogo primarily produces gold dore ranging in size from several hundred to 1,000 ounces; this dore contains impurities and is refined outside of Alaska. In 2009, Pogo produced 389,808 troy ounces of gold.
The Pogo deposit is mined using the conventional underground mining techniques of cut and fill and drift and fill. The main workings are located underneath Liese Creek; an underground water treatment facility handles the high flows of water that must be pumped from the underground structures in order for mining to occur. The mine complex includes a mill, camp, dry stack tailings pile, waste rock dumps, recycle water tailings pond, an airstrip, gravel pits, laydown and fuel storage areas, and a local network of roads. Final construction costs for the mine were $357 million - 17% higher than the original projected estimates of $300 million.
Gold is recovered using gravity (60%) and floatation and cyanide vat leaching (40%). During life of mine, an estimated 11 million tons of tailings will be produced, with approximately half returned underground as paste backfill. The remaining tailings are stored above ground in the dry stack tailings impoundment located in Liese Creek. At the end of mine life, Sumitomo will close and seal the underground workings and reclaim the mine site. Sumitomo has a local (Alaska) hire policy; in 2009, the mine and mill employed 299 employees and contracted with another 101 persons. Employees work two weeks on, one week off, with personnel transported via company buses from Fairbanks and Delta. Company policy strictly forbids on-site employees from hunting or fishing on Pogo property, and, as is typical in remote work sites, there is a zero tolerance drug and alcohol policy.
Exploration activities in 2009 focused on surface and underground drilling within the mine area. Forty four surface holes were drilled totaling 52,655 feet. Thirty five underground holes were drilled, totaling 17,745 feet.
Reclamation & Financial Responsibility
An updated reclamation and closure cost estimate was submitted in February 2005 and again in October 2008 and is currently under review by the Department of Natural Resources. The required financial assurance totals $4,518,865 for the access road and power line and $23,079,740 for the mine site facility.
Teck Cominco constructed a 49-mile road across state lands from the Richardson Highway to the Pogo mine; the road also includes a bridge spanning the Goodpaster River. The road is maintained and operated on a year-around basis, and during life-of-mine, is closed to the public. However, after the mine closes, the first 23 miles, which wind out in and out of the Tanana Valley State Forest, will be open for public use. The remaining 26 miles of road, which is leased to the company, will be closed and removed by the company unless the lease is otherwise negotiated — a process which would be subject to public notification and comment.
Pogo Stakeholders Groups
During the permitting phase of the mine, the Northern Alaska Environmental Center filed an administrative appeal of the final National Pollution Discharge Elimination System (NPDES) permit wherein the US Environmental Protection Agency declined to consider mine tailings as waste, thus approving discharge of mine tailings into Liese Creek. In an effort to avoid lengthy delays in construction resulting from an appeal process, and with the intervention of the State of Alaska, the Northern Alaska Environmental Center and Teck Cominco reached a negotiated settlement agreement.
As part of the settlement agreement, Teck Cominco agreed to install two additional groundwater monitoring wells near the Goodpaster River, fund annual fish studies on the Goodpaster for at least ten years, and establish a stakeholder group that would regularly review mine operations and environmental compliance. The seven-member group is composed of representatives from fishing, mining, environment/conservation, subsistence, hunting, and local resident. The initial members were selected by the Commissioner of the Department of Natural Resources, following a public recruitment and nomination process. There are no term lengths or limits; vacancies following a resignation are filled by the Commissioner selecting from a list of three candidates submitted by the stakeholders group. The group meets no less than twice a year with at least one meeting at the mine site.
Click here to download a factsheet on the Pogo Mine.
last modified April 28, 2010 02:14 PM