Chile’s environmental regulator, the Superintendency of the Environment (SMA), has issued a definitive closure order for Lundin Mining’s Alcaparrosa mine following a nearly three-year investigation into a massive sinkhole that appeared near the operation in 2022. The decision marks a significant regulatory action against the Toronto-based miner, which has been found guilty of multiple environmental violations.

The sinkhole, measuring 36 meters in diameter and over 60 meters deep, emerged near the Alcaparrosa mine in northern Chile, drawing global attention. Initial investigations linked the incident to excessive ore extraction, leading to structural instability. On Thursday, SMA officials confirmed that Lundin Mining was responsible for four environmental breaches, including unauthorized infrastructure modifications, mineral over-extraction, and failure to comply with environmental permits. As a consequence, the regulator has not only mandated the permanent closure of the mine but has also imposed a fine of $3.41 million.

Marie Claude Plumer, head of the SMA, stated that the company’s operations extended into unauthorized areas, reaching the Copiapó River aquifer. This intrusion allowed excess water infiltration, which weakened the surrounding rock mass, contributing to the formation of the sinkhole. “The company caused irreparable environmental damage,” Plumer asserted. She also reinforced the need for strict compliance with environmental regulations, emphasizing that “the rules are clear and must be followed. Companies are fully aware of the conditions under which they are allowed to operate.”

Lundin Mining’s local subsidiary, Ojos del Salado, has acknowledged the ruling and stated that it will review the decision before determining its next steps. The company has 10 business days to pay the fine or 15 days to appeal the closure order before Chile’s Environmental Tribunal.

The Alcaparrosa mine is part of the Ojos del Salado mining complex, in which Lundin Mining holds an 80% stake. The remaining 20% is owned by Japan’s Sumitomo Metal Mining and Sumitomo Corporation. The complex also includes the Santos underground mine, which remains operational.

Sinkholes typically form in areas where underground water accumulates without proper drainage, gradually eroding subterranean rock formations. While some develop slowly over time, others can appear suddenly, swallowing vehicles, homes, and infrastructure. Mining operations—both active and abandoned—are particularly susceptible to sinkhole formation due to extensive rock and ore extraction.

The closure of Alcaparrosa underscores the growing regulatory scrutiny facing mining operations in Chile, one of the world’s top mining jurisdictions. The decision highlights the risks of non-compliance with environmental regulations and the potential consequences of unsustainable mining practices.