Measuring 200m-deep and 50m in diameter, the sinkhole emerged above the underground operation at the Alcaparrosa copper mine.
Alcaparrosa is part of the Ojos del Salado operation located within the Candelaria Copper Mining Complex.
As part of the latest plan, the Canadian firm intends to expel water leaked into the mine.
Lundin local unit president Luis Sanchez told the news agency that the studies are in ‘decisive stages’ to determine the causes of the sinkhole and a ‘technical body is already receiving all the information to be able to draw conclusions’.
However, regardless of the study outcome, Lundin is planning to fill the hole using materials such as rocks and sand that hold the same characteristics as a riverbed. It plans to fully seal the mine’s affected part.
Without disclosing the total cost or amount of material required, Sanchez said the firm had already invested $10m to address the issue.
Sanchez said that initially, between 300 litres per second (l/s) and 330l/s of water had been leaking into the mine. The water leak level, however, has now reduced to 10l/s -30l/s as a result of sealing work.
Sanchez added: “We are observing a positive development in the recovery of the levels in the aquifer and this means that we can look positively at this solution and we can say that we are not facing irreparable damage, as some authorities have indicated.”
As part of the programme, the firm intends to pump 1.3 million cubic metres of water located in the lower levels of the reservoir to other industrial users in the area.