Dissolved Copper ConcentrationsWe monitor dissolved copper concentrations in the rivers around Ok Tedi mine to ensure they are within safe levels.
Dissolved copper concentrations in the riverine systems around Ok Tedi mine are at levels which are of ecological, but not of human health concern.
The dissolved copper concentration risk has decreased since 2008 due to lower ore cut-off copper grade from the waste rock dumps and decreased copper from tailings as a result of improved recoveries in the milling circuits coupled with the removal of copper-bearing sulphides from the tailings as part of the Mine Waste Tailings Project (MWTP).
Decreased copper in the tailings has resulted in a decrease in dissolved copper concentration in the Lower Ok Tedi and Middle Fly reach of the river from approximately 20 µg/L to approximately 7 µg/L. The levels of copper at all monitoring sites are the lowest recorded since 1986.