Thanks to the innovative and highly-efficient recycling and conservation practices in which Oyu Tolgoi has invested, the company uses just 520 litres of water to process each tonne of ore. This is less than half the global average amount of water consumed by similar mines.
And in 2013, out of all the water used for production at Oyu Tolgoi, 84 per cent was reused. Most of the water is required by the concentrator, where the mined ore is transformed into the saleable product: copper concentrate.
Water is recycled across many parts of the operation, including from truck washing and cooling systems. Household wastewater is treated at the seven wastewater treatment plants. Some of the recycled water is used to spray on roads for dust suppression, and in the concentrator.
Among other water management procedures in place, Oyu Tolgoi is recovering groundwater that surfaces when ore is removed in the open-pit mine. High-efficiency thickeners are being used to reclaim water from tailings – the mixture of process water and finely-ground rock that is left over after the valuable minerals have been removed. A floating cover has been installed on the lagoon that holds water piped from the aquifer, to prevent evaporation.
To make sure that it understands and can manage any impacts of its operations on the surrounding water resources, Oyu Tolgoi has been monitoring the levels and quality of water in herders’ hand-dug wells since 2003. And since 2011, herders have been making their own records for comparison with Oyu Tolgoi’s. The data has not demonstrated negative impact on the wells due to the project.