Climate change has been caused by several different factors. The Environmental Protection Agency estimates that 8 to 10 percent of all man made methane emissions are a result of coal mining . Other forms of mining would only cause this number to increase. It would be safe to say that mining has been a significant contributor to climate change.
Now lets look at the impacts of climate change. The United Nations Intergovernmental Panel on Climate Change: “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts” . Not surprisingly one of these “pervasive” impacts is that if we continue on our current trajectory we will only have 60% of the water we need by 2030 . Funnily enough mining is a water intensive activity. For instance in 2006 the copper mining industry alone used 1.3 billion cubic meters of water .
So when the Financial Times says, “the [mining] industry’s spending on water has increased from $3.4 billion in 2009 to nearly $10 billion in 2013” it is hard to shed a tear . In fact turning to BHP Billiton’s (one of the largest mining companies in the world) 2015 Sustainability Report we can see that 85% of its water input was from water that is not drinkable. A significant amount, 30%, of the water was seawater . Looking at the Sustaibility Reports of other mining companies it is the same story. How have they done this?
Using Water Efficiently
Exhibit A: Pressure on BHP Billiton
In Adelaide, Australia, BHP Billiton has in its copper, gold and uranium mine has initiated a water savings project. The project “reduces the consumption of Great Artesian Basin (GAB)water by optimizing water recovery and recycling and by substituting poor-quality local groundwater in some areas”. First BHP Billiton looked at existing data to examine how water is flows to GAB’s springs. Then some of the steps it undertook were “replacing high-quality water with hypersaline groundwater for dust suppression on roads, implementing a lockout system for water valves to ensure water is recycled from storage ponds and implementing advanced process controls to reduce water losses to tailings dams that store waste”. Further steps included covering open water storages to mitigate evaporation, increasing reuse of wastewater and replacing high-quality water with hypersaline ground water in several processes. This saved around 3000 Megalitres a year of water .
Using Lower-Quality Water Sources
Minera Esparanza in its copper and gold mine in Antofagasta, Chile required 20 million cubic meters a year, but was located in the Atacama Desert. So it designed its processing plant to use untreated seawater. Following a pilot project, supply pipe network was built to carry the seawater 145 km from the Pacific coast to the mine.
The process of transporting the seawater involves filtering it for suspended solids, adding a corrosion inhibitor reagent, and passing through four pumping stations. Its final destination is the concentration plant . In general these are very uncomplicated process and the key is in the design of the plant.
Exhibit B: How Desalination Works
BHP Billition, in its Escondida joint venture with Rio Tinto, invested in $3 billion dollar desalination plant that has a capacity of 2,500 liters per second ,. “Apart from the coastal desalination plant itself, the project includes two pipelines, four high-pressure pump stations, a reservoir at the mine site and high-voltage infrastructure to power the system.” In fact there are 16 other such similar desalination projects underway or in discussion in Chile itself.
It is clear to see that the mining industry has, in essence, bought their way out of their water problem. High capital expenditure projects have been their solution. Is this enough though? Ultimately mining companies must also concentrate on the root cause of their problem. Reducing their methane and CO2 emissions is the next step. While there are regulations in place, the mining industry must look at the emission reductions as an investment that will pay off in the future. (678 words)