Río Sonora copper sulphate spill and repair fund
- The company and officials said I was safe. A former official later acknowledged they could not speak of a full clean-up. AZCIR
- In 2023 Mexico's environment ministry said the heavy metals were still in me. Mongabay Latam
- 288.8 km of my rivers were polluted.Described as a basin figure in the El Imparcial item of February 2026; how it was measured is not stated.
- Company or project Grupo México and officials (2014–15): Said the river was safe; a former official later acknowledged they could not speak of a full clean-up. AZCIR
- Company or project Germán Larrea, owner of Grupo México (2019): Was reported saying the river was dirty rather than contaminated. Zeta Tijuana
- Government and regulators Semarnat (2023): Said heavy metals continued. Mongabay Latam
In August 2014 about 40,000 cubic metres of acidic copper sulphate solution from a Grupo México mine entered the Sonora River in Mexico. A fund committed at 2,000 million pesos was closed in 2017 after about 1,000 million had been deposited; the Supreme Court later held the closure invalid, and in February 2026 the federal government said 500 of an agreed 1,500 million pesos had been deposited.
Millions of pesos. Fund deposits by closure in 2017 (2,000 million committed); damage estimate by civil society, author not named in the sources reviewed.
Status As of February 2026: the Supreme Court held the fund's closure invalid in January 2020; President Sheinbaum said the company had deposited 500 of 1,500 million pesos agreed; no outcome of the Semarnat criminal complaint was found.
- Grupo México — Partial closure orders on the mine were lifted in 2015; the mine kept operating. Expansión
- Grupo México subsidiaries — Supplied much of the drinking water and health services bought with the fund, according to organisations cited by Expansión Política. Expansión Política
- Grupo México — A quarter of its contribution to the fund could be deducted from tax, according to accountants quoted by PODER (reported by Expansión Política). Expansión Política
- Communities along the river — About 22,000 people reported affected; average payment about 15,000 pesos plus a water tank. Expansión Política
- Grupo México — A fine of almost 23 million pesos and a fund contribution; the Supreme Court held the fund's closure invalid in 2020. Business & Human Rights Resource Centre
- The Sonora River — About 40,000 m³ of acidic solution; heavy metals still present in 2023, per Semarnat. Mongabay Latam
- Communities along the Sonora River — About 22,000 people affected in 2014 and about 24,000 in the June 2025 report; basin committees said in June 2025 there was still no plan, date or budget. El Imparcial
What happened
On 6 August 2014 the Buenavista del Cobre mine of Grupo México released about 40,000 cubic metres of acidic copper sulphate solution into the Sonora River, in the Mexican state of Sonora. AZCIR reported about 11 million gallons (42 million litres). About 22,000 people were reported affected along the river from Arizpe to Ures; later local reports give between 20,000 and 24,000.
The company and officials said the river was safe, AZCIR reported in 2015; a former official later acknowledged that they could not speak of a full clean-up. The environment enforcement agency Profepa fined the company almost 23 million pesos and presented the amount as the maximum under the law (Expansión, 2 March 2015); AZCIR reported a fine of about US$1.5 million for more than 50 violations. Partial closure orders on parts of the mine were lifted in 2015.
The company committed 2,000 million pesos to a repair fund (AZCIR reported it as US$150 million). The fund was closed on 7 February 2017, when about 1,000 million pesos had been paid in. Vanguardia reported that 61% of the fund had been spent. Expansión Política reported on 10 May 2018 that civil organisations alleged irregularities: much of the drinking water and health services were bought from the group's own subsidiaries, a requested clinic was not built, and payments averaged about 15,000 pesos per person plus a water tank. Accountants quoted by the group PODER assessed that a quarter of the company's contribution to the fund could be deducted from tax. In September 2019 Zeta Tijuana reported the owner of Grupo México, Germán Larrea, saying the river was dirty rather than contaminated.
Mexico's Supreme Court held on 15 January 2020 that the closure of the fund was invalid (Business & Human Rights Resource Centre); Grupo Animal (January 2026) likewise reported that the court annulled the closure. In 2023 the environment ministry, Semarnat, said the spill was not an accident but negligence, that heavy metals were still present, and that it had filed a criminal complaint against the company (Vanguardia; Mongabay Latam).
In June 2025 El Imparcial reported that basin committees said there was still no plan, date or budget, with about 24,000 people affected. In February 2026 President Claudia Sheinbaum said the company had deposited 500 million of the 1,500 million pesos agreed and demanded the remaining 1,000 million.
- 20146 August: about 40,000 m³ of acidic copper sulphate solution enters the Sonora River; about 22,000 people reported affected
- 2015Profepa fines the company almost 23 million pesos, presented as the maximum; partial closure orders lifted (Expansión, 2 March)
- 20177 February: repair fund closed with about 1,000 of 2,000 million pesos paid in
- 2018Civil organisations allege irregularities in the fund (Expansión Política, 10 May)
- 2019Owner Germán Larrea is reported saying the river is not contaminated but dirty (Zeta Tijuana, September)
- 202015 January: Supreme Court holds the fund's closure invalid
- 2023Semarnat says the spill was not an accident and files a criminal complaint (Vanguardia, September; Mongabay Latam, October)
- 2025Basin committees say there is still no plan, date or budget (El Imparcial, 24 June)
- 2026President Sheinbaum says the company deposited 500 of 1,500 million pesos agreed (El Imparcial, 18 February)
What was said
Where accounts differ
Each party's account, side by side, with its source. The record does not settle these points; it shows them.
Said the river was safe; a former official later acknowledged they could not speak of a full clean-up.
AZCIRWas reported saying the river was dirty rather than contaminated.
Zeta TijuanaSaid it was not an accident but negligence, and filed a criminal complaint.
VanguardiaDeclared the fund had achieved its purpose, as cited from Vanguardia reporting.
VanguardiaDeclared the fund had achieved its purpose, as cited from the same reporting.
VanguardiaAlleged irregularities: services bought from the group's own subsidiaries, a requested clinic not built, average payments of about 15,000 pesos per person.
Expansión PolíticaHeld that the closure of the fund was invalid.
Business & Human Rights Resource CentreSaid there was still no plan, date or budget.
El ImparcialSaid the company had deposited 500 million of an agreed 1,500 million pesos.
El Imparcial2,000 million pesos committed (AZCIR reported US$150 million); about 1,000 million pesos received by closure.
AZCIRDamage estimated at 20,508 million pesos.
How it looked
Shown
- The river was safe.Grupo México and officials, as reported by AZCIR (2015) · AZCIR
- The 23 million peso fine was the maximum under the law.Profepa, as reported by Expansión (2 March 2015) · Expansión
- The repair fund had achieved its purpose.Profepa and Grupo México, as cited from Vanguardia reporting · Vanguardia
Recorded
- About 40,000 m³ of acidic copper sulphate solution entered the river in August 2014; about 22,000 people affected.
- A former official acknowledged that they could not speak of a full clean-up.
- The fund closed on 7 February 2017 with about 1,000 of 2,000 million pesos paid in.
- Vanguardia: 61% of the fund had been spent when it closed.
- Most drinking-water and health services were bought from the group's own subsidiaries, the requested clinic was not built, and payments averaged about 15,000 pesos per person plus a water tank (allegations of organisations reported by Expansión Política).
- The Supreme Court held on 15 January 2020 that the closure of the fund was invalid.
- Semarnat found the spill was not an accident and that heavy metals persisted; it filed a criminal complaint.
- February 2026: 500 of 1,500 million pesos agreed had been deposited.
Who gained
Reached nature or the ground
Gained elsewhere
Responses on record
- grupo-mexico (2014–2015): Said, with officials, that the river was safe; a former official acknowledged they could not speak of a full clean-up. · AZCIR
- grupo-mexico (September 2019): Owner Germán Larrea was reported by Zeta Tijuana as saying the Sonora River was not contaminated but dirty. · Zeta Tijuana
- grupo-mexico (2017): Described, with Profepa, as saying the repair fund achieved its purpose (cited from Vanguardia reporting). · Vanguardia
- profepa (March 2015): Presented the fine of almost 23 million pesos as the maximum under the legislation. · Expansión
- semarnat (2023): The spill was not an accident but negligence; heavy metals continued; filed a criminal complaint against Grupo México. · Vanguardia
- mexico-gov (18 February 2026): President Sheinbaum said the company had deposited 500 million of the 1,500 million pesos agreed and demanded the remaining 1,000 million. · El Imparcial
In court and with insurers
Lawsuits and rulings
- 2015-03Claimant wonMXN 23m million pesos (almost), presented by Profepa as the maximum under the lawProfepa fine for the 2014 spillProfepa (Mexican environmental enforcement agency) · Administrative · Profepa → Grupo México
Profepa fined the company almost 23 million pesos (Expansión, 2 March 2015); AZCIR reported a fine of about US$1.5 million for more than 50 violations. Partial closure orders on parts of the mine were lifted in 2015. Expansión
- 2020-01-15Claimant wonClosure of the Río Sonora fundSupreme Court of Mexico · Administrative · Not named in the record (reported as Río Sonora communities) → Not named in the record
The Supreme Court held on 15 January 2020 that the closure of the fund was invalid (Business & Human Rights Resource Centre); Grupo Animal (January 2026) reported that the court annulled the closure. Business & Human Rights Resource Centre
- 2023–OngoingCriminal complaint by SemarnatMexican federal prosecution (not named in the record) · Criminal · Semarnat → Grupo México
The environment ministry said the spill was not an accident, that heavy metals continued, and filed a complaint. Mongabay Latam and Vanguardia report it in 2023; N+ in 2024. No outcome in the record. Mongabay Latam
- 2026OngoingMXN 1.5bn million pesos agreed, of which 500 million deposited2026 reparation agreement with the federal governmentFederal government of Mexico · Administrative · Federal government → Grupo México
President Sheinbaum said the company had deposited 500 million of the 1,500 million pesos agreed. How this relates to the 2017 fund and the Supreme Court decision is not stated in the sources reviewed. El Imparcial
Insurers
What nature saw
Nature's report opens this page. Below: further outcomes measured on the ground.
What we don't know
Nature
- Disputed Was the river safe and cleaned up?
Accounts
Record
- Unclear Actual spending of the fund is not established: Vanguardia reported 61% spent at closure, while Expansión Política figures list about 1,000 million pesos in the fund, 951.77 million pesos under "beneficiaries" and 141.5 million pesos without documentation.
- Disputed The fund's size is reported in different currencies: 2,000 million pesos in Mexican sources and US$150 million by AZCIR.
- Disputed Release volume and affected population differ by source: 40,000 m³ or 11 million gallons (42 million litres); 20,000 to 24,000 people.
- Disputed The date of the ministry's criminal complaint differs: 2023 (Vanguardia, Mongabay Latam) and 2024 (N+). No outcome of the complaint was found.
- Insufficient Reported but not independently verified: a quarter of the company's contribution to the fund was tax-deductible (accountants cited by the group PODER; PODER's own analysis was not reviewed).
- Insufficient Reported but not independently verified: that Semarnat treated the remediation as completed in 2017.
- Insufficient Reported but not independently verified: that the company closed the fund early and did not comply with the court's order to reopen it, and that it had not been reopened as of 2024.
- Insufficient Reported but not independently verified: the company first attributed the release to exceptional rainfall.
- Insufficient Reported but not independently verified: approval of the mine's new tailings dam by a preventive report in August 2013 and a 2018 Supreme Court order for a consultation.
- None on record Implementation of the 2026 agreement: ongoing, no result on record.
Did the harm stop?
Not established. The fund closed in 2017 with about half the committed amount paid in, and the Supreme Court held the closure invalid. Semarnat said in 2023 that heavy metals were still present; basin committees said in June 2025 that there was still no plan, date or budget.
Who paid?
The company paid a fine of almost 23 million pesos and deposited about 1,000 million pesos into a fund committed at 2,000 million; in February 2026 the federal government said it had deposited a further 500 million of 1,500 million agreed. Communities along the river (20,000 to 24,000 people in local reports) said in June 2025 that they had seen no justice or reparation. The civil-society damage estimate is 20,508 million pesos.
Sources
Press and investigations
- Grupo México pagará casi 23 mdp por derrame en río SonoraExpansión · 2015-03-02
- Organizaciones acusan irregularidades en el fideicomiso Río SonoraExpansión Política · 2018-05-10
- Grupo México, responsable de derrame de tóxicos en río SonoraMongabay Latam · 2023-10
- Sheinbaum exige a Grupo México pagar los mil millones pendientes por el derrame en el Río SonoraEl Imparcial · 2026-02-18
- A 11 años del derrame en el Río Sonora, comunidades siguen sin ver justicia ni reparaciónEl Imparcial · 2025-06-24
- Reparación Río Sonora: hasta no ver no creerGrupo Animal · 2026-01
Communities and civil society
- Grupo México lawsuit re toxic spill in MexicoBusiness & Human Rights Resource Centre · 2020-01-15
Connected cases
- ASARCO bankruptcy environmental settlement and Grupo México's return in 2009 United States · 2009
- Grupo México (Company) — here: Mining group; operator of the Buenavista del Cobre mine and fund contributor; there: Regained ASARCO from bankruptcy in 2009
- Make Sunsets stratospheric balloon launches (Mexico) Mexico · 2022–2025
- Government of Mexico (Government) — here: Federal government under President Sheinbaum; statement of February 2026; there: Government that announced a ban
- Mexico IBRD catastrophe bonds (Otis, Polo) and FONDEN abolition Mexico · 2021–2026
- Government of Mexico (Government) — here: Federal government under President Sheinbaum; statement of February 2026; there: Bond sponsor and beneficiary (Hacienda)
- Mexico ordered to pay $37.1m over denied seabed phosphate permit Mexico · 2016–2024
- Government of Mexico (Government) — here: Federal government under President Sheinbaum; statement of February 2026; there: respondent; refused the seabed permit
- Mexico water concessions concentration Mexico · 1995–2026
- Government of Mexico (Government) — here: Federal government under President Sheinbaum; statement of February 2026; there: Government
- Sembrando Vida (Sowing Life) Mexico · 2019–2022
- Government of Mexico (Government) — here: Federal government under President Sheinbaum; statement of February 2026; there: Programme owner and payer