Ok Tedi Mining Limited (OTML) is committed to achieving improvements in its environmental performance and, as a minimum requirement, meeting the legal obligations under the current Environmental Regime.

Ok Tedi mining operations are centred on the Mt Fubilan copper and gold deposit in the upper Fly River catchment in the remote Star Mountains, Western Province and only 16 km east of the Indonesian border. The mine is located at approximately 2, 000m relative elevation above sea level in an area of dense rainforest where annual average rainfall is approximately 10,000 mm per annum.

The mine is permitted to discharge both tailings and waste rocks into the river. The main environmental issues associated with mining are sediment aggradation, fish biomass, forest dieback, copper toxicity and acid drainage (ARD). To manage the issues OTML implemented a number of programs which include dredging of sand from Ok Tedi River bed at Bige since 1998 to mitigate the flooding and dieback; and the removal of pyrite from the tailings and safely storing it below permanent water table at Bige since 2008 to mitigate ARD and copper toxicity.

A number of non-mining factors impact environment in a number of ways. For example, bush fires set by local communities in search of food during extreme dry weather (El Nino) causes forest dieback. El Nino also leads to drying up of shallow off river water bodies which then causes resident fish to die from heat stress and starvation, eaten by other fish and animals and also from fishing pressure by the local communities. Commercial fishing, population increase, improved fishing practice and introduced fish species also impact fish biomass.


The Ok Tedi Mine is governed by the Mining (Ok Tedi Agreement) Act 1976 with amendments and supplements.

The Ninth Supplemental Agreement that was passed by the PNG Parliament in 2001 has adopted the current “Environmental Regime” which contains OTML’s environmental obligations. The Regime is underpinned by six environmental values which are aimed at ensuring availability and safety of land and water based resources, water quality and Fly River channel navigability. The Environmental Regime requires OTML to undertake nine Compliance monitoring activities at the frequency and locations stipulated in the Regime and to prepare an Annual Environmental Report (AER) for the State on the findings