Water – it’s simply our most precious resource, and few industries depend on reliable sources of water more than mining, oil and gas, and pulp and paper. Whether in mineral extraction, in processing, or in dust suppression in mining, or mixed with chemicals and proppants and fracking fluid for oil extraction, water’s importance to the world’s resource sector is immeasurable.
Without ample and dependable supplies of water, the world’s resource sector would cease to exist. In America, mining-heavy states like California, Nevada, Utah and Texas withdraw 201 gallons to 1,140 million gallons of water, according to the United States Geological Survey (USGS).
In Australia, mining remains a major industry driver, responsible for over half of the nation’s total export revenues. Contributing billions of dollars annually to the economy, it is estimated Australia’s mining sector – along with manufacturing and some other industries – consumes approximately 20 per cent of the country’s water. Despite efficiencies in place overseeing how water is used, cleaned, and reused, shortages have historically plagued parts of Australia.
Prone to severe droughts every 18 years, one of the longest-lasting was south-eastern Australia’s ‘Millennium’ drought, starting in 1996 and lasting to 2010, making water all that more important.
Playing a vital role in virtually every stage of the mining process, water is consumed in large amounts to cool drilling machinery, and used during mineral processing and many other activities. To ensure adequate supplies, water management – tracking how much enters and leaves mine sites – is a necessity.
Certain kinds of mining, like gold and copper, use greater quantities of water than others, such as diamond or platinum, and water scarcity remains an issue pretty well everywhere that mining exists. With much of the planet’s mining taking place in locations where conditions are arid, such as the northern region of Chile, monitoring water intake and output is a science of necessity.
Out of the need for conservation, safeguarding the environment, and corporate responsibility, the world’s mining sector has made great progress in how it uses, treats, recycles and discharges the water it uses daily. A decade ago, the International Council on Mining & Metals (ICMM) – representing 27 mining and metals businesses and almost 40 associations – created a water working group “to consider water issues that the sector faces and ways in which the industry can respond,” according to its report, Water management in mining: a selection of case studies.
Underlining the importance of responsible mining-company water management, the report discusses the challenges and opportunities faced by the industry in locations including South Africa, Australia, Peru, Japan, Argentina, and the United States.
Since water at mine sites is connected to many pathways, water flowing to and from mines impacts much more than just the mine and immediate areas. Everything from groundwater to surface water must be considered, along with lakes, streams, local communities, businesses and agriculture. These areas can, and often are, impacted by mining activities, including the discharge of water.
While water can be trucked to site through commercial delivery companies, this amount is rarely enough to meet mining needs, necessitating water from other sources.
From initial exploration to mine design and planning, water supply and its concomitant sourcing, water storage tanks, and dams are crucial for operations to be successful. Water asset construction management is necessary at every stage, from mine construction and operation to closure. At the end of a mine’s life cycle, water is required for wastewater remediation and management, drainage treatment, and environmental-impact assessments and studies.
Waste not, want not
Worldwide, mining, and oil and gas extraction and exploration have been under fire for years regarding water consumption, disposal, runoff, and its occasionally disastrous impact on waterways, water tables, farms, animal habitats, and humans.
Fortunately, mining companies today are doing all they can to reduce the environmental impact of their sites. In the United States, the National Pollutant Discharge Elimination System (NPDES), created by the Clean Water Act (CWA) in 1972, exists to limit water pollution through the regulation of sources such as mining. Authorized by the Environmental Protection Agency (EPA), permits are required prior to discharge into “navigable waters (waters used for commerce and travel),” and covers organic and inorganic pollutants including earth and rocks, pesticides, heavy metals, and others.
Along with restricting the discharge of pollutants, the Clean Water Act also “requires enforceable water quality standards to maintain overall water quality.” Penalties for violating NPDES permits are severe, ranging from $25,000 to $50,000 per day, three to 15 years behind bars and fines up to $250,000 along with prison time.
Proper water management requires a balance between using enough water to perform necessary functions like slurry transportation and mineral extraction, and ensuring waterways are protected from harmful waste products and the sulfidic minerals found in metallic ore deposits. When present in tailings dams, open pits and other mine site locations, these sulfides oxidize on exposure to air and oxygen-rich water, resulting in acidic water.
Resource sector leaders
Realizing that no water means no business, mining operations are stepping up and changing their stance from water management to water stewardship. Precisely monitoring their own water consumption and balancing how they use water and the impact on surrounding areas, their water stewardship addresses environmental, societal, and economic implications. According to the Scotland-based Alliance for Water Stewardship (AWS), this encompasses the attitudinal shift of “taking care of something that we do not own.”
Defining water stewardship as “the use of water that is socially and culturally equitable, environmentally sustainable and economically beneficial, achieved through a stakeholder-inclusive process that includes both site and catchment-based actions,” the AWS focuses on five outcomes: good water governance; sustainable water balance; good water quality status; important water-related areas; and safe water, sanitation and hygiene for all.
The future of water use
With so much mining taking place in drought-prone areas of the world, the need for better water management and water stewardship will only increase.
Adding to the complexity of water scarcity are a multitude of issues including public attitudes, pressure from stakeholders to do more with less and remain profitable, preservation of wildlife and watersheds, and the minimizing of mining’s impact on agricultural regions. To address these concerns, resource-based businesses will be under relentless pressure to implement water management procedures as they evolve.
More than just measuring water consumption and discharge, mine sites and other resource-sector businesses nowadays must balance how they access water, and how they implement reuse and recycling. They must comply with existing standards, and work with others to evaluate risks and benefits.
Some may think this onerous, but success stories abound, with mining companies of all sizes working diligently to not only reduce the amount of water they use, but also improving cleaning and re-use while lowering discharge.
One of the most dramatic successes involves major mining company Rio Tinto. At its famous Argyle Diamond Mine in Australia’s arid East Kimberley region, the company was able to reduce the water sourced from Lake Argyle from 3,500 megaliters to just 300 megaliters in only four years. To achieve this, Rio Tinto made investments and improvements, including capturing, storing, and recycling water used for processing.
In mining, oil and gas, and other resource-based industries, there will probably always be massive use of water. But with water scarcity increasing globally, new technologies will see water cleaned and re-used multiple times before it’s safely discharged back into rivers, lakes, streams and oceans.