Case study - Grasberg mine (environmental impacts of resource extraction and distribution)

Question 1

Where is Grasberg mine?

Answer 1

Tembagapura, province of Papua, Indonesia. Near headwaters of Aghawagon-Otomono-Ajkwa river system

Question 2

What are the environmental impacts of production on landuse?

Answer 2

• Flooding
• Acid rock drainage
• Pollution

Question 3

What are the issues with flooding?

Answer 3

High discharge of tailings into the Ajkwa river > reduce capacity > increasing flood risk. Waste rock dump in Lake Wanagan > poor stability of dumps can cause fatal landslides

Question 4

What are issues with acid rock drainage?

Answer 4

copper deposits contain metal sulfides which when crushed and exposed to air became unstable and form strong acids (PH3) and copper leaching > kills surround vegetation and enters groundwater supplies > implications for local people and marine fauna.

Question 5

What is an issue with pollution?

Answer 5

Tailings (sludge left following ore extraction from rock) dumped into the Ajkwa River (approx 700, 000 tonnes per day) (and Arafura Sea) > acidic runoff; copper toxicity (stops respiration in fish as damages gills) and increased turbidity due to high sediment levels has made waters unsuitable for aquatic life (loss of native fish/mollusks). Levees are inadequate to reduce this.
Tailings contaminate surrounding land (heavy metal contamination) and can smother vegetation > leading to forest loss, including in the Lorentz National Park (Nature 2014 identified 138 km2 forest loss (1987-2014 (42x greater than the mine itself).
Bioaccumulation of heavy metals (including copper) as plants grown in tailings store them in tissues affecting food chain.
Water eventually drains in the Arafura Sea > impacting bottom feeder organisms and mangrove swamps

Question 6

What are the environmental imacts of distribution?

Answer 6

• Distribution networks
  Three pipelines transport slurry containing copper-gold concentrate to Amampare a port town in Papua, Indonesia where it is filtered and shipped to smelters (approx. 63 miles).
  Some road networks for distribution of solid material

Question 7

What are the environmental impacts?

Answer 7

Construction of infrastructure - habitat destruction and road construction encourages further deforestation
Transportation of slurry requires concentrate ore to be mixed with water > creation of waste water
Vehicles used for transportation > enhanced greenhouse effect/acid rain