## Facts

- Peruvian residents of Ilo and nearby areas sued a U.S. mining company operating in Peru, alleging emissions of sulfur dioxide and fine heavy-metal particulates into local air and water.
- Plaintiffs claimed the pollution caused respiratory and related health injuries and harmed the local environment.
- Plaintiffs brought federal claims under the Alien Tort Claims Act (Alien Tort Statute), 28 U.S.C. § 1350, asserting violations of international law-based rights to life, health, and sustainable development.
- The district court dismissed, concluding plaintiffs had not identified a binding customary international law norm, and alternatively dismissed on forum non conveniens grounds.
- Plaintiffs appealed; the court of appeals addressed subject-matter jurisdiction under the ATS first.

## Issues

1. Whether the complaint alleged a violation of a specific, universal, and obligatory norm of customary international law sufficient to support jurisdiction under the ATS.
2. Whether asserted international-law rights to life, health, and sustainable development supply an actionable ATS norm for intranational environmental pollution causing personal injury to residents of the same state.
3. If ATS jurisdiction is lacking, whether the court should reach alternative grounds for dismissal such as forum non conveniens.

## Decision

- The Second Circuit affirmed dismissal for lack of subject-matter jurisdiction under the ATS.
- The court held plaintiffs failed to plead conduct violating a well-established, universally recognized, and clearly defined norm of customary international law.
- The court rejected plaintiffs’ proposed “shockingly egregious” standard as an impermissible substitute for identifying an existing, clearly defined international norm.
- Because jurisdiction failed at the threshold, the court did not address the district court’s forum non conveniens ruling.

## Legal Principles

- ATS jurisdiction requires an alleged violation of a norm of customary international law that is specific, universal, and obligatory, with definitional clarity comparable to historically recognized paradigms.
- Customary international law is shown by general and consistent state practice followed out of a sense of legal obligation (opinio juris); aspirational statements and policy goals are not enough.
- Broad formulations of rights (including generalized invocations of life, health, or sustainable development) do not establish an actionable ATS norm absent a concrete, widely accepted prohibition.
- Materials such as treaties with limited ratification, soft-law declarations, and expert opinions may inform analysis but do not establish custom without consistent state practice and opinio juris.
- Claims targeting purely intranational environmental harm to a state’s own residents require clear evidence of a customary international law norm regulating such domestic conduct.

## Conclusion

The Second Circuit held that alleged domestic pollution in Peru, framed as violations of international-law rights to life, health, and sustainable development, did not meet the ATS requirement of a specific, universal, and obligatory customary international law norm; accordingly, federal courts lacked subject-matter jurisdiction and dismissal was affirmed.


Flores v. S. Peru Copper Corp., 343 F.3d 140 (2d Cir. 2003)