The Ministry for the Ecological Transition of Spain has awarded the multinational Geoalcali, a subsidiary of the Australian company Highfiels Resources, the mining project for the extraction of potash between Navarra and Zaragoza, which, according to various sources, would be the largest in the Basque Country and the Spanish State, along with the Esa reservoir. Potash is often used to produce fertilizer and pesticide.

The reactions have been immediate, and against them various parties, social partners and environmental groups have spoken. Ekologistak Martxan has denounced that since the project was presented almost a decade ago, the company has only put in place facilities to carry it forward, “instead of turning it back from the beginning”.

The Muga project has been the subject of several institutional arguments since 2015, such as the Government of Navarra or the Ebro Hydrographic Confederation (CHE), but in 2019 it obtained the environmental authorization of the Geoalcali and from there it has been made even easier to start with the exploitation. The CHE informs the public that if the project has been approved it will be for compliance with the environmental warnings made by the institutions.

But ecologists and experts in the field are not so sure. The mine would have a total width of 1,700 hectares and a depth of 600 metres, and the waste generated would pose a major problem for the miners, according to the sources. What are the risks of the Muga project?

Salt Mount 57 metres

Subai Erakuntza lists some of them in a report published in 2020, taking into account previous experience in Erreniega. In this place, the heritage of Posistemas de Navarra is still detected, as landfills and wells remain unrehabilitated and are poorly closed, which causes the pollution to reach the Arga River. In addition, land is often sunk and earthquakes are also occurring.

In the case of the Muga project, the damage will be greater due to the size of the mine itself. Subai explained that the peak of the salt residues generated in the extraction of the potash could be at least 57 metres – 13 million cubic metres – although it is probably much higher, as the technique of salt reintroduction is not feasible in his opinion.

In 25 years, it is intended to extract 6.3 million tonnes of buried material each year, which would require more than 1,000 trucks a day, according to the report. In addition, a large amount of water is needed for extraction, which would be extracted from the Yesa reservoir.

Precisely, the proximity of the Yesa reservoir is one of the most worrying reasons, as the mine galleries are less than a kilometer away. In these galleries the salt melts when it enters and that generates more water, “this chain reaction will make the problem very difficult to stop.”

Subai recalls in this document that the environment of the Yesa reservoir is very unstable and with a high seismic activity: “Cracks, sinks, scratches and other harmful effects can occur both in the mine and in the reservoir itself.”