Ok Tedi Environmental Disaster - Environmental Impact

Environmental Impact

In 1999, BHP's CEO, Paul Anderson said that the Ok Tedi Mine was "the mine is not compatible with our environmental values and the company should never have become involved."

The mine operators discharge 80 million tons of tailings, overburden and mine-induced erosion into the river system each year.

Following heavy rainfall, mine tailings are swept into the surrounding rain forest, swamps and creeks, and have left behind 30 square kilometers of dead forest. Thick gray sludge from the mine is visible throughout the Fly River system, although its effects downriver are not as severe. Chemicals from the tailings killed or contaminated fish, although they are still eaten by the people of the surrounding villages. However, fish counts decrease closer to the mine. The massive amount of mine-derived waste dumped into the river exceeded its carrying capacity. This dumping resulted in the river bed being raised 10 m, causing a relatively deep and slow river to become shallower and develop rapids, thereby disrupting indigenous transportation routes. Flooding, caused by the raised riverbed, left a thick layer of contaminated mud on the flood plain among plantations of taro, bananas and sago palm that are the staples of the local diet. About 1300 square kilometers were damaged in this way. The concentration of copper in the water is about 30 times above the standard level, but it is below the World Health Organisation (WHO) standards.

The original plans included an Environmental Impact Statement that required a tailings dam be built. This would allow heavy metals and solid particles to settle, before releasing the clean ‘high-water’ into the river system where remaining contaminants would be diluted. In 1984 an earthquake caused the half built dam to collapse. The company continued operations without the dam, initially because BHP argued that it would be too expensive to rebuild it. Subsequently, the PNG government decided a dam wasn’t necessary, in the wake of the closure of the Panguna mine.

Most of Papua New Guinea's land is held under a system of native title, with ownership divided amongst many small clans, while the central government retains control over how resources that lie under the ground are used. The 2000 members of the clan that held ownership of the land on which the mine would be built were included in the formal negotiations. They received money, jobs, vocational training, and infrastructure improvements.

Also, as a consequence of geotechnical problems, there are no waste retention facilities on the premises. This allowed all ore processing residues, waste rock and overburden to be discharged into the Ok Tedi River.