With 40 years of experience in the field of mining U.S. hydrogeologist and geochemist Robert E. Moran is an authority on the subject. His involvement with mining began first in the Bureau of Economic Geology of Texas and the United States Geological Survey before he went on to become a consultant to governments, companies, lawyers, universities and NGOs. His work has led to the suspension of large projects in Peru, El Salvador and Romania, and the cancellation of others in Peru and Argentina.
Moran has now been consultant to the Controller General since 2012 and first heard about Anglogold Ashanti’s gold project in La Colosa, Cajamarca (Tolima), four years ago.
Speaking to El Tiempo about the impacts of large-scale mining, before answering any questions he issues two cautions about the following interview: “I am not an activist, nor am I against mining”. Despite this Moran argues that, although there are companies that go to great lengths to not generate negative impacts, these are ‘always’ present, not only during the operation, but after mine closure, even centuries later.
It is Moran’s belief that countries only now beginning to experience the boom in the mining of metals may still have a hope that impacts can be prevented. It is with reference to one of these countries, Colombia, that Moran discusses the development of mining projects in the paramos (high-altitude moorlands) considered vital for water production and biodiversity.
Are there areas where there should be no mining?
I think there are areas where open pit mining should not be allowed. Areas of aesthetic, biological, agriculture or political importance should not be given over for mining. In Western Europe, the USA or Canada, for example, it is politically impossible to make a mine of this size near a city.
So how can the country benefit from the wealth contained in the subsoil without generating these large impacts?
They must find a way to develop strong regulatory bodies, with the aim of providing a balance of power between regulators and companies, and ensure long-term impacts are borne by those who generate them, not the general public. In the EU or Canada it is normal for companies to deliver a bond or policy before a mine’s operations start. In these mines large amounts of insurance, between $150 million and $300 million, are required because the long-term impact, the part that is really expensive – is water pollution.
What could contaminate the waters around Colosa?
The rock contains not only gold and silver but sulfides and later these can generate sulfur acids, which generate high environmental costs. Mineralised rock may also contain other potentially toxic metals and chemicals, which are released into the environment forming acidic waters. These may include arsenic, antimony, mercury, copper, lead and selenium.
In Rio Tinto in southern Spain, there is evidence of acid formations in the rocks, caused by natural processes, but also by ancient and modern mining. This acid has been released into groundwater and surface water for between 8,000 and 10,000 years.
You also have to think about the situation in Johannesburg, South Africa – a city that is sitting atop a potential catastrophe. Below it are tunnels, most the product of old gold mining. This mining has generated much acid drainage water that is rising to the surface and affecting places where there are shallow wells and water treatment plants. This has generated a costly problem for the city, hence the question: who will pay for that? Which is not a short-term problem.
What is the water consumption for the Anglogold project?
In 2009, the project manager said the company will require about 1 m3 of water per second to process each ton of rock which is removed from the pit and sent to the processing plant. This information was quoted by AngloGold Ashanti (AGA) at public meetings and accepted at the time. However AGA recently doubled their estimate of the potential haul of the mine to 24 million gold ounces meaning the active life of the mine is now estimated at between 15 and 25 years. This means the mine must contain not only gold but also silver and other minerals of a high value.
La Colosa is not the only mine of concern in Cajamarca, there is also Piedras (Tolima), where Anglogold performed exploratory activities. Here there is a fear concerning rock leaching. What impact would this have?
I understand that Piedras is a significant aquifer. There will be wells near this place for removing water used for the plant and the water table will fall. Some of the local wells and springs will dry up, if there is a river near this level it may erode. The water used in the plant and in the leaching process, separating the gold from other materials, will be contaminated because these use cyanide and other toxic substances. The company will try to recycle as much water as possible, but the truth is that much will be lost and contaminated.
Might that leaching process also alter the landscape?
AGA intends to conduct activities in Piedras that generate lots of waste containing metals and other potentially toxic contaminants. These residues may remain on the site for a long period if not managed properly and chemicals may be released into the environment.
Waste processing plants create large accumulations, artificial mountains of cyanide leachate. This phenomena can be seen in Yanacocha, Peru, where they reach more than 100 metres high. However, we still do not know the details of the AGA plans, so we cannot yet determine the exact size of the accumulations of debris from leaching.
Impacts are very difficult to overcome then…
They are difficult to avoid and when present are difficult to correct. What I’m saying is that some companies do a very good job to avoid these problems, but it is incredibly difficult and expensive. Most, after operating 20 or 25 years, leave behind some very long-term impacts.
How can sustainable mining be achieved?
The word sustainable has become one of those words that young people in the United States are using, such as “awesome”, but that does not correspond to the real meaning. Sustainability is about the long term, that is thousands of years. Experience has shown me that there are always negative impacts, but that does not mean there are no benefits. What happens is that many of these negative impacts are paid by the public and not by the mining company.
Why are companies increasingly moving into countries with no traditional mining sector?
This is occurring especially in developing countries. Since the costs of labour are cheaper, regulation is much weaker and most valuable minerals elsewhere have already been discovered. The big mining companies are coming to Central Asia, Africa, South America and Pacific islands. What I am saying is not anti-mining, but I do believe that there needs to be a better balance of power between the local and the corporate, if not, the long-term costs will be borne by the public.
How does water become contaminated and what are the risks?
In coal mining, such as gold and other metals, the most serious problem is chronic pollution, slow semi-invisible pollution resulting from water filtration from waste piles, water pits and lagoons into groundwater. This can then contaminate surface water with all kinds of salts, metals and metalloids. We can already see signs of this type of pollution near mining sites in Cesar.
This also generates a growing competition for water, as companies must pump water out of the pits for many years, resulting in the depletion of local groundwater levels and the drying of wells, springs, marshes and rivers. There may also be impacts downstream.
Coal dust and waste rocks, can be carried into rivers by the wind and contribute to the degradation of water quality. Water that was once used in agriculture, livestock watering and domestic consumption, may become too degraded for these uses if untreated. This dust often contains physical particles and chemicals, such as metals, metalloids, and explosive residue fuels, several of which are toxic to humans and other organisms.
These impacts are difficult to offset if baseline data has not been collected before the start of operation of the mine, and if mines have already been operational for several years.
This article was translated from Spanish. See here for original article: Los impactos de la minería los va a pagar la gente.