We work in environments where water is scarce – like the Gobi Desert in Mongolia – and others with large variations in rainfall from year to year – like Weipa in far North Australia.
In Mongolia, where our Oyu Tolgoi copper operations are based, we have invested in recycling and conservation practices that make it one of the most water efficient mines of its kind in the world. More than 80% of the water used in production is recycled and, on average, Oyu Tolgoi uses around half the industry average to process copper ore.
At other sites, where we mine below the water table, we need to remove and dispose of existing groundwater.
Many of our sites are also experiencing changes in rainfall and water availability due to climate change, so we take this into consideration too.
Whatever the context, we see ourselves as water stewards and we take that commitment seriously, because water is essential – not just for human life, health, and the environment, but also for economic prosperity. Our processing plants, refineries, smelters and mines use water to process ore, manage dust and promote rehabilitation. In some instances, water is used to produce hydroelectricity to power our operations and minimise our emissions to the environment. We also supply drinking water to our people and sometimes to surrounding communities.
We are committed to balancing our operational needs with those of local communities, Traditional Owners, ecosystems and local and international regulatory requirements. We seek to avoid disturbance or degradation of water resources like lakes, streams and groundwater aquifers, and to control the quality and quantity of the water we use and then return to the environment. We also seek to use water as efficiently as possible in the design and every day operations of our sites.
In order to do this, we have refined the way we consider water risk against the following four themes: water resource; quantity and quality; dewatering; and long-term obligations. These themes provide the framework for us to identify, assess, manage and communicate water risk both internally and within the communities where we operate.
Based on the World Business Council Global Water Assessment Tool, in 2018 43% of our managed sites are assessed as operating in a “water stressed” environment. Of these sites, only one was locally assessed as having its operations marginally impacted by water availability.
We support the new International Council on Mining & Metals (ICMM) position statement on water stewardship and, from 2019, will report our practices against the commitments outlined in the statement:
- Apply strong and transparent water governance
- Manage water at operations effectively
- Collaborate to achieve responsible and sustainable water use
Water is precious in the arid South Gobi region, which receives on average 97 mm of rainfall each year. Local herders rely on shallow sources of groundwater from springs and wells for their animals. And we use water to produce copper, which is used in everything from computers and smartphones to solar panels and electric cars.
Our Oyu Tolgoi team goes to great lengths to use its allocated water efficiently, and balance our needs with those of the local community. To find a sustainable source of water, that would not impact local supplies, we surveyed the area seeking a new underground water supply. The work uncovered the Gunii Hooloi aquifer – which was more than 150-metres deep, holding around 6.8 billion cubic metres of non-drinkable saline water.
We also work with herders, local people and the government to protect the water in boreholes, existing wells and other community water supplies. One way we do this is through our community water monitoring programme – we monitor the levels and quality of water in herders’ hand-dug wells, and local herders make their own water records for comparison. The data has shown there has been no negative impact on the wells from the mine’s operations.
We have also invested in recycling and conservation practices that make Oyu Tolgoi one of the most water efficient mines of its kind in the world. More than 80% of the water used in production is recycled, and on average Oyu Tolgoi uses 520 litres of water to process a tonne of ore – around half the industry average.
Water Stewardship Target Programme 2019 – 2023
Water targets remain at the heart of our integrated water management approach. In October 2018, the Rio Tinto Sustainability Committee approved the high-level proposal for the 2019-2023 water targets of a more focused approach that aligns with our Sustainability Framework, and is consistent with the International Council of Mining and Metals (ICMM) Position Statement on Water Stewardship (January 2017).
The 2019-2023 timeline represents our third set of global water targets and builds upon the successes and learnings of the previous programmes.
We have redesigned our water targets for 2019-2023 to comprise one Group target and six site based local targets. We did this because we wanted to be more transparent about our water usage, and our water risk profile, management and challenges.
Learning from past targets, we created new targets that will build the datasets we need to drive good water stewardship in the future. We aim to use the targets and data to improve our performance over the next five years through a programme of risk awareness and response.
Our Group Target is that by 2023 we will disclose – for all managed operations – their permitted surface water allocation volumes, their annual allocation usage and the associated surface water allocation catchment rainfall runoff volume estimate.
To ensure we focus on the right issues and with appropriate resources, we have established new site-specific targets for the period 2019-2023 at operational sites where water is a recognised risk.
The six water target projects were chosen with consideration of our ICMM commitments, their community and environment interdependencies and the associated site water risk profiles.
Cresencio Anchetta – known to his colleagues as "Junior" – has worked at our Boron operations in California for many years. After joining as an analyst in the laboratory at Boron, Junior moved into the engineering department, and today works as a senior environmental technician.
One of Junior's favourite things to do is monitor groundwater. After packing his kit in the flat bed of his truck, Junior drives out into the Mojave Desert, and begins his tour of the 120 evaluation wells in the arid landscape.
"I like it because water is important to us, and to me personally. It also gives me an excuse to enjoy the view of the beautiful desert," he says.
Junior takes samples of water from deep underground and analyses them for properties like pH, conductivity and temperature. He also measures soil moisture content. The samples are sent to the laboratory for further analysis, and the results added to our environmental database.
The work is an important part of our approach to protecting water quality, and provides assurance to stakeholders that this valuable resource is being properly managed.