Table of Contents:

Pebble Mine, Alaska

The New York Times (September 22, 2020) reported that the Pebble project, a major open-pit mine project that would be dug in a remote sparsely populated part of Southwest Alaska, has been fought over a decade and a half by those who say it will provide much-needed economic development and others who argue it will cause environmental harm, especially to salmon that are the basis for subsistence fishing by Alaska natives and the wild salmon fishery in Bristol Bay, one of the world’s largest.

The Corp of Engineers issued a final environmental impact statement last month, which found

that the project as proposed would not cause long-term changes in the health of the commercial

fisheries. The Corp is expected to make a final decision on a permit for the project within weeks.

TABLE 17.4

Final Scorings of Each Environmental Component in Sarcheshmeh Copper Mine (Monjezi, M et. al)

Impacting Factors

Environmental Components

Human Health and Safety

Social

Relationship

Water

Quality

Air

Quality

Use of Territory

Flora and Fauna

Above

ground

Underground

Landscape

Noise

Economy

Alteration of area’s potential resources

2.4

2.3

0

0

17.1

1.9

0

0

8.6

0

0

Exposition, visibility of the pit

0

2.3

0

0

8.6

0

0

0

8.6

0

0

Interference with above groundwater

11.2

0

31.3

0

0

17.5

46.7

00

20

0

0

Interference with under-groundwater

2.8

0

31.3

0

0

0

0

46.7

0

0

0

Increase in vehicular traffic

14.4

27.7

0

0

12.9

22.5

0

0

6.4

0

0

Atmospheric release of gas and dust

16

7.7

III

100

0

25

33.3

0

7.1

0

0

Fly rock

8

0

0

0

0

6.3

00

0

0

0

0

Noise

5.6

21.6

0

0

0

4.4

00

0

0

56

0

Ground vibration

11.2

10.8

0

0

00

0

0

23.3

0

0

0

Employment of local workforce

0

0

0

0

0

0

0

0

0

0

70

Total

71.6

72.4

73.3

100

38.6

77.6

80

70

50.7

62

70

That would allow construction to proceed after state permits are obtained, which is expected to take three years.

Pebble Mine is a large porphyry copper, gold, and molybdenum mineral deposit in the Bristol Bay region of Southwest Alaska, near Lake Iliamna and Lake Clark. As of August 2020, mine developers are seeking federal permits from the U.S. Army Corps of Engineers, the U.S. Coast Guard, and the Bureau of Safety and Environmental Engineering. State permitting will follow, and developers expect it to take up to three years.

The Pebble prospect is in a remote, wild, and generally uninhabited part of the Bristol Bay watershed. The nearest communities, about 20 miles (32 km) distance, are the villages Nondation, Newhalen, and Iliamnana. The site is 200 miles (320 km) southwest of Anchorage, Alaska.

Pebble is approximately 15 miles (24 km) north of, and upstream of Lake Liliamna. Upper Talarik Creek flows into Lake Iliamna, which flows through the Kvichak River into Bristol Bay. Waters in the Koktuli River drain into the Mulchatna River, a tributary of the Nushagak River, which empties into Bristol Bay at Dillingham. Water from Lake Clark, approximately 20 miles (32 km) east of Pebble, flows down the Newhalen River to Lake Iliamna.

The Ore Body

The Pebble Project is a copper gold-gold-molybdenum porphyry deposit in the advanced exploration stage. The project is located on state land in the Bristol Bay region of southwest Alaska, approximately 17 miles northwest of the community of Iliamna. Pebble consists of two contiguous deposits. Pebble West is the near-surface resource of approximately 4.1 billion metric tons. Pebble East is significantly deeper than Pebble West and contains an estimated resource at 3.4 billion metric tons.

In 2008, Pebble was estimated to be the second-largest ore deposit of its type in the world. In February 2010, a resource estimate reported that the combined Pebble deposit mineral resources of East and West comprise 5.94 billion tons of ore, grading 0.78% CUEQ, containing 55 billion pounds of copper, 67 million of gold, and 3.3 billion pounds of molybdenum, as well as 4.84 tons of ore, as inferred mineral resources grading 0.53% CuEQ containing 25.6 billion pounds of copper, 40.4 million ounces of gold, and 2.3 billion pounds of molybdenum.

The 2014 resource estimate includes 6.44 billion tons in the measured and indicated categories, containing 57 billion lbs of copper, 70 million oz of gold, 3.4 billion lbs of molybdenum, and 344 million oz of silver, and 4.46 billion tons in the inferred category, containing 24.5 billion lbs. of copper, 37 million oz of gold, 2.2 billion pounds of molybdenum, and 170 million oz silver. Quantities of palladium and rhenium also occur in the deposit.

By dollar value, slightly more than half of the value is from copper, with the remainder split roughly equally between gold and molybdenum. By-products of silver, rhenium, and palladium metals would also be recovered.

 
Source
< Prev   CONTENTS   Source   Next >