RS: Grasberg Mine

Question 1

Where is Grasberg Mine located?

Answer 1

Indonesia.

Near headwaters of Aghawagon-Otomono-Ajkwa river system.

Question 2

What are the 4 environmental impacts of mine construction?

Answer 2

Land loss

Flooding

Acid rock drainage

Pollution

Question 3

Grasberg mine - land loss?

Answer 3

Approx 1 mile wide = loss of biodiversity

Question 4

Grasberg mine - flooding?

Answer 4

High discharge of tailings into the Ajkwa river = reduced capacity = increasing flood risk.

Waste rock dump in Lake Wanagan = poor stability of dumps can cause fatal landslides

Question 5

Grasberg mine = acid rock drainage?

Answer 5

Copper deposits result in strong acids + copper leaching

Kills surrounding vegetation and contaminates water.

Question 6

Grasberg mine - pollution?

Answer 6

Tailings dumped in Ajkwa River = acidic runoff, copper toxicity (damages fish gills), and increased turbidity = loss of native fish

Tailings contaminate land = loss of forest in Lorentz National Park

Water drains into Arafura Sea = impacts mangrove swamps

Question 7

What are the main environmental impacts of the mine’s distribution networks?

Answer 7

• Infrastructure = habitat destruction + deforestation
• Transportation of slurry = conventrate ore has to be mixed with water = waste water
• Vehicle usage = enhanced greenhouse effect

Question 8

How can the environmental impacts be reduced?

Answer 8

• Restoration plans
• Baffle mounds = reduce noise/dust pollution
• Holding lagoons = remove suspended solids before water enters rivers