Anglo American has secured an environmental permit for a $3bn extension of its Los Bronces copper project in Chile.

The permit has been approved by Chile’s Ministry of Environment.

The project will access higher-grade ore from a new underground section of the mine.

Located in the Andes Mountains, the Los Bronces Integrated Project is being criticised by environmentalists and social groups over concerns about its long-term impact on the area’s water supply and nearby glaciers.

Last year, amid environmental criticism, Anglo American said it would use desalinated water to meet almost half the water requirements of its Los Bronces mine from 2025.

The company said in a statement: “The project uses the mine’s existing processing facilities, optimises water efficiency, has no impact on glaciers and requires no additional freshwater or tailings facilities.”

The Chilean Ministry of Environment said the permit for the project has now been authorised by the committee due to a number of “demanding” environmental requirements established by Anglo American.

Commenting on the approval, the National Mining Society (Sonami) union said the permit is a “powerful signal” for mining and investors.

Sonami president Cristián Argandoña said: “The project contemplates high sustainability standards to avoid the affectation of glaciers, including an underground operation so as not to intervene on the surface, as well as the adoption of a series of measures of local effect for the control of emissions.”

The Los Bronces Integrated Project will allow continued production from the deposit until 2036. It is expected to have copper production of 150,000 tonnes.

During the construction phase, the project is expected to employ 2,850 people. It is anticipated to create 2,000 jobs once operational.

The project is owned by Anglo American Sur, in which Anglo American owns a 50.1% stake, while the Codelco-Mitsui consortium holds a 29.5% interest and Mitsubishi owns a 20.4% stake.