Two major mining companies have outlined plans to pursue parallel environmental approvals for a shared open-pit copper operation that would combine adjacent mining areas in Chile. Documents presented to environmental authorities in January describe what the firms call an "unprecedented" twin-track process: two largely identical environmental impact applications, each to be filed by the end of December.
The proposals concern the Andina and Los Bronces pits, operated respectively by Codelco and Anglo American, which sit next to one another in Chile's main copper-producing region. Under the plan, the rock barrier separating the two pits would be excavated to create a single contiguous pit. Ore from that combined excavation would be routed interchangeably to both companies' processing plants, while waste rock would be deposited into each company's existing waste dumps.
The companies finalized their commercial agreement in September. The project is expected to contribute about 120,000 metric tons of copper annually between 2030 and 2051 and to deliver at least $5 billion in pre-tax value, according to the documents. Codelco's chairman, Maximo Pacheco, and a source at Anglo American confirmed the firms' intention to file the two applications at the end of the year.
Legal and operational considerations drove the decision to pursue two separate filings rather than a single joint submission. One presentation notes that Chile's constitution requires Codelco to maintain ownership of its mining concessions, making a single, consolidated filing legally unviable under current rules. The companies evaluated a three-application alternative - one application from each miner to extend the useful life of their respective mines and a third from a joint entity that would manage the combined operation - but dismissed that option because it would have required surrendering existing open-pit environmental permits to accommodate a combined mine.
Instead, the twin-track model would see both firms submit mirror applications that apply the same environmental management measures in areas of operational overlap. The approach preserves each company's separate concession ownership and also allows for the possibility that the mines could revert to independent operations in the future.
On the ground, the plan entails creating a single pit while keeping the expansion largely within the current mine footprints. Ore would flow interchangeably to both processing facilities, reducing the need for duplicate processing infrastructure. However, documents also indicate that changes will be required to existing waste dumps, tailings facilities, pipelines and other support infrastructure to permit integrated operations.
The companies argue that sharing infrastructure will reduce duplicated facilities, lower freshwater consumption and lessen pressure on the surrounding environment. At the same time, they acknowledge material challenges and risks associated with the arrangement. Close coordination with regulators will be necessary, a requirement the companies warn could strain a slow-moving environmental review system.
Public scrutiny also features prominently among the flagged risks. The project has high visibility and could attract opposition from environmental groups and affected communities, who might contend that two separate reviews mask the true scale of impacts. In particular, Los Bronces has a history of scrutiny from residents, regulators and courts over alleged impacts related to air quality, water use and nearby glaciers in the high Andes where the mine operates.
While the twin-track approach is presented as a way to reduce the risk of underestimating environmental impacts, the companies concede it could produce duplicate or unnecessary environmental management measures. The documents indicate plans to begin stakeholder outreach, including engagement with local communities, in the second half of the year.
As described in the filings, the integrated operation is intended to optimize resource extraction while maintaining the legal and operational independence of each miner's concession. Ore routing flexibility and shared infrastructure are central elements of the operational design, but both companies have detailed the adjustments to support infrastructure that will be required for the two mines to function as an integrated system.
Key dates outlined in the filings include the January presentation of the environmental studies to regulators and the planned submission of twin applications in December. The projected production increase and estimated pre-tax value are specified for the period 2030 to 2051. The filings also describe internal deliberations that rejected a three-application approach due to the need to surrender existing permits, and they stress the constitutional constraint on Codelco's concession ownership as a decisive factor in opting for two parallel filings.
Both companies emphasize risk management in the documents, noting the need for careful coordination with authorities and the potential for heightened public and community scrutiny. They also acknowledge the operational trade-offs, including the prospect of duplicative environmental controls and the infrastructure modifications required to support integrated pit operations.
The companies' next public-facing steps, according to the documents, will include stakeholder outreach planned for the second half of the year as they prepare to file their respective environmental impact applications at the end of December.