Argentina’s Supreme Court Dismisses Two-Decade Environmental Lawsuit Against Vaca Muerta Oil Companies

The Supreme Court of Justice rejected the collective environmental damage claim filed by the Patagonian Landowners Association (ASSUPA) against YPF, Chevron, Pan American Energy, Pluspetrol, Total Austral, Vista Oil & Gas, Pampa Energía, CAPEX, PCR, and other firms operating in the Neuquén Basin. The ruling, signed by Chief Justice Horacio Rosatti and co-justices Silvina Andalaf Casiello, Rocío Alcalá, and Luis Renato Rabbi Baldi Cabanillas, concluded that the plaintiff failed to demonstrate specific environmental harm extending beyond provincial boundaries, a prerequisite for Supreme Court original jurisdiction.

The court criticized ASSUPA’s complaint for “vagueness and imprecision,” stating the organization relied on general hypotheses rather than concrete evidence. The justices noted that “the evidence offered by the plaintiff does not pursue corroboration of factual circumstances, but rather seeks investigation into conjectures formulated in the complaint.” ASSUPA had sought to use judicial expert reports to subsequently identify contamination sources and assign responsibility to individual companies, which the court determined revealed the inability to specify “circumstances of time, manner and place” of alleged violations.

The tribunal emphasized that ASSUPA failed to provide technical studies or environmental proof demonstrating plausible interjurisdictional impact, despite warnings in previous resolutions dating to 2014. The association made generalized allegations about contamination of soils, water courses, aquifers and air throughout the Neuquén Basin without identifying concrete cases. The court characterized attempts to broadly link all hydrocarbon activity to collective environmental damage as “a vain effort” to prove contamination exceeded provincial limits.

ASSUPA had demanded comprehensive environmental remediation, creation of a special restoration fund under the General Environmental Law, and preventive measures against future damage. The organization invoked constitutional articles 41 and 43 and international environmental treaties related to climate change. The court ruled that environmental control and monitoring within each province falls primarily to local authorities under constitutional federalism principles, reaffirming that not all environmental disputes automatically escalate to Supreme Court jurisdiction.

The national government and the provinces of Buenos Aires, La Pampa, Mendoza, and Neuquén participated as third parties. The court distributed legal costs to each party due to the case’s juridical complexity.