Collahuasi opens citizen participation following Environmental Court ruling

The Environmental Evaluation Service (SEA) of the Tarapacá Region notified the opening of a citizen participation process for 20 business days in the evaluation of the Environmental Impact Declaration of the project “Modification of waste rock extraction at the Rosario open pit, new Ujina quarry, and adjustments to the tailings pumping system, Cordillera Collahuasi Operation.” The call is officialized through resolution No. 20260100136, dated September 3, 2026, published in the Official Gazette of the Republic of Chile No. 44,549, on Saturday, September 12, 2026.

The project owner is Compañía Minera Doña Inés de Collahuasi SCM, the country’s largest copper producer. The initiative was submitted on June 13, 2026, and modifies the project “Infrastructure Development and Productive Capacity Improvement of Collahuasi,” approved via exempt resolution No. 20219900112, dated December 21, 2021.

Judicial Background

The evaluation is being rolled back by mandate of the Second Environmental Court, which in its case Role No. R-430-2023 ordered a review of matters relating to the human environment and marine environment components in the Puerto Collahuasi sector and those associated with the desalination plant. The court did not suspend the effects of the environmental qualification resolution (RCA) regarding the non-contested aspects, which will be preserved in the new RCA to be issued following the rollback.

The modification falls under article 2, sub-literal g.1 of the RSEIA, as it constitutes “significant changes” relative to the originally approved project.

Scope of Modifications

The proposed works are located in areas already used by Collahuasi’s industrial and mining operations, in the “Cordillera” sector, located in the Tarapacá Region, Tamarugal province, Pica commune. The changes include:

• Recovery of the waste rock extraction rate in the Rosario open pit, for a period of 4 years (2027-2030).
• Incorporation of a quarry in the Ujina sector for the construction of the main wall of the Pampa Pabellón tailings deposit.
• Relocation and adjustment of the tailings pumping system.

How to Participate

In accordance with article 95 of DS No. 40, any natural or legal person may submit observations on the project within the legal period of 20 business days, starting from the business day following the publication of the resolution. The full text is available on the website www.sea.gob.cl and at the offices of the Regional Directorate of the SEA of Tarapacá, at Riquelme Street No. 1081, Iquique, from 9:00 to 13:30 hours, Monday to Friday. The notification is signed by Sandra Peña Miño, Acting Regional Director of the SEA Tarapacá Region.

The opening of this process restores the possibility for the region’s communities to voice their opinion on a strategic operation for Chilean mining, in a context where environmental justice corrected the original procedure. The result of the citizen participation and the complementary re-evaluation will define the future of Collahuasi’s new RCA and its impact on the human and marine environment of the Puerto Collahuasi sector.

Source: Official Gazette of the Republic of Chile, No. 44,549, Saturday, September 12, 2026, Section I (General Norms), p. 1 (official reference: CVE 2870105).