"Mendoza” Case Closed: What Did the Supreme Court Rule?

On October 22, 2024, the Argentine Supreme Court issued a ruling that closed the compliance supervision of the ruling that had been issued on July 8, 2008 in the case “Mendoza, Beatriz Silvia c/ Estado Nacional y otros s/ Daños y Perjuicios (daños derivados de la contaminación ambiental del río Matanza-Riachuelo.”

 

Following this ruling, the control of the activities of the Matanza-Riachuelo Basin Authority (ACUMAR) will be channeled through the mechanisms provided for in Law 26168 (articles 7—last part—and 8) and in the procedures for the control of activities of the federal public administration.

 

In its ruling, the Court provided an overview of the origin of the claim and the decisions made since its intervention (Recitals 1 to 12). In particular, it emphasized the rulings issued on June 20, 2006–which defined the object of the claim–and on July 8, 2008–which ordered the remediation of the environmental damage and placed on ACUMAR the responsibility of implementing the Comprehensive Environmental Clean-Up Plan (PISA).

 

Subsequently, the Court held that, having defined the goals to be achieved, considering the implementation of the PISA, and having appointed the agency responsible for its implementation (ie., ACUMAR), the institutional objectives proposed in the ruling of July 8, 2008, had been fulfilled (Recital 15).

 

After describing the progress made regarding the obligations in the PISA, the Court concluded that its intervention served its purpose of “generating the structural reform that was essential to align the activities of the State with the principles and rights enshrined in the Constitution,” and that the results of the new structures do not fall within its mission, considering that such control would require a prolonged or indefinite time (Recitals 16 and 17).

 

For that reason, the Court concluded that it was appropriate to close the case–and its related proceedings–with the following clarifications:

 

1. The proceedings currently pending before execution courts, related to the implementation of the PISA, will continue before the courts with  corresponding territorial and subject matter jurisdictions, and the relevant ordinary procedural rules will apply.

 

2. Dockets open to control the PISA obligations will be closed, notwithstanding their pending administrative proceedings before ACUMAR.

 

Regarding the collective moral damage the plaintiffs claimed, the Court stated that it would be pointless “due to being premature and conjectural” to rule on this matter, since its admissibility depends on whether it can be determined that the remediation of the environmental damage or any aspect of it is technically impossible (General Environmental Law 25675, article 28). The Court highlighted that ACUMAR's task is an ongoing one, and this prevents reaching a conclusion with the necessary degree of certainty regarding the existence of irreversible damages.

 

On the other hand, the Court understood that it was not appropriate to set a compensation aimed at creating a common recovery fund to cover the costs of environment remediation, since the Federal State, the City of Buenos Aires, the Province of Buenos Aires, and ACUMAR have been bearing the costs of such remediation.

 

The Court held that ACUMAR has a special legal mechanism to claim what it deems appropriate from the companies [(Law 26168, article 9). Accordingly, it understood that it was not appropriate to rule on the exceptions the defendants raised (Recital 18).

 

Finally, the Court ruled that each party must bear its own costs and fees, given the novelty of the matter and the particularities around the proceedings (Recital 18).

 

The ruling is not final, since it has been challenged by the two groups of plaintiffs: the group of neighbors who filed the claim—who challenged both the closure of the case and the imposition of legal costs and fees—and the civil society organizations that are part of the Collegiate Body.