Acid drainage from copper mining

By Constantia Achilleos

26 June 2017

Expert: Konstantia Achilleos
Category: Expert Insights

Abandoned copper mines in Cyprus offer spectacular views for nature lovers. More and more visitors at the Troodos Geopark go to mines throughout the year to take their photos. The impressive colours in mining lakes amaze foreigners and locals alike. But there is another dimension to the issue: protection of the environment. Mine run-off is acidic, due to its low pH, and poses a risk of pollution to the surface and ground water.

The problem is heightened in abandoned mines, in which copper mining began 4 to 5 thousand years ago, meaning there was never a provision for environmental protection. In the modern mining industry, environmental legislation sets strict standards for both the operation and rehabilitation of the mine when mining ends.

Threat of environmental degradation is not only limited to the mine site. The issue is more complicated because nature has no borders, unlike what we believe. Pollution can spread across a radius of several kilometres, with pollutants entering into the earth’s surface and ground water. Soil can be saturated by toxic water, constituting a danger to human health and contributing to the degradation of biodiversity.

Acid drainages have concentrations of heavy metals, e.g. arsenic, lead, copper. These metals are released in nature and according to the medium (water or soil) they will accumulate and their concentration may pose a risk to public health. Some metals, such as arsenic, are considered dangerous to human health even in the lowest of doses.

In ancient times, people did not know about the effect of heavy metals. On the contrary, these were widely used, even in medicine. It was Hippocrates who first noted that environmental factors influenced the spread of disease. Today, scientists have concluded that heavy metals on the whole can be poisons or medicines, always depending on their dose in the human body.

Similarly to humans, animals are also affected, and vegetation can also be degraded with metal absorption. Hence soil decontamination in copper mines can be achieved by using specific kinds of plants that absorb pollutants. Finally, we rely on technology and expertise to provide comprehensive measures for environmental conservation and the protection of human health.

A version of this article was featured in the Trooding Newspaper issue 3.