Cerrejon, an opencast coal mine in the north east of Colombia, is the largest coal mine in Latin America and one of the largest in the world. Cerrejon is owned by Carbones del Cerrejón – made up of three London-listed companies: Anglo American, BHP and Glencore.

Over 200 indigenous Wayuu communities suffer the effects of Carbones del Cerrejón’s neo-colonial policies, which include violations of their human rights, ill-health and environmental destruction. Cerrejón has diverted numerous waterways, including the Arroyo Bruno (Bruno river), in order to extract coal from underneath the riverbeds and meet the company’s production target of exceeding 32 million tonnes per year. Additionally, Cerrejón has licenses to dump industrial wastewater into the Bruno and the Ranchería River, leading to heavy metal contamination in the region’s principle water sources.

In early July 2019, Fulbright researchers (a US grants programme) based in La Guajira, Colombia, organized a small water study in the zone of influence of Cerrejon mine. Using equipment borrowed from the University of Los Andes, they tested the temperature, pH, conductivity, and dissolved oxygen of 12 different sites (including three points along the Ranchería River, one point along the Arroyo Bruno, one rainwater catchment reservoir, a natural spring and three wells in Wayuu communities).

On 8th July, a sample was taken from the Ranchería River downstream of one of Cerrejón’s industrial dump sites and brought to a certified laboratory in Bogota for analysis. The lab results, which included 32 parameters, showed an alarming level of mercury (0.0749 mg/L) in this sample from the region’s most important river, upon which hundreds of thousands of Guajiros rely. The WHO drinking water guidelines set a limit of 0.006 mg of mercury per liter, while the EPA maximum contaminate level goal (MCLG) is 0.002 mg/L. The Bogota-based organization Terrae notes in their analysis of the results that the mercury level found in this sample taken on July 8th is 70 times the limit established by the Resolution 2115 of 2007 (0.001 mg/l) for Chemical characteristics that have a recognized adverse effect on human health.

Mercury is a neuro toxin that can cause a myriad of health problems, and exposure to high concentrations of mercury is fatal. Many Wayuu communities downstream of the site where the sample was taken use the river water for cleaning, bathing, and cooking. Most communities in La Guajira do not have potable water, or a consistent supply. Some families, particularly indigenous Wayuu, must use the river water for drinking, even though all who were interviewed during the study claimed to be aware that the water was contaminated. It can be observed that most Wayuu children living along the river suffer from skin conditions, which may be linked to water contamination.

In September 2019, researchers from the University of Los Andes wrote a letter to the department of La Guajira’s environmental authorities at Corpoguajira urging them to take this concerning data seriously. Almost three months later, it appears that no action has been taken to increase water monitoring or to follow up on the fact that the Ranchería River may contain deadly levels of mercury and that Wayuu children are regularly exposed to this contamination.

Watch this video about the Arroyo Bruno and take action to protect the river and the health of those who depend on it.