## Facts

- Individuals and organizations alleged potential harm from radioactive effluents discharged into Colorado waters by two nuclear power plants operating under federal nuclear licenses.
- The dispute concerned whether the Federal Water Pollution Control Act (FWPCA), as amended in 1972, required the Environmental Protection Agency (EPA) to regulate certain radioactive discharges that were already regulated under the Atomic Energy Act (AEA).
- The EPA Administrator took the position that EPA lacked authority under the FWPCA to regulate discharges of AEA-covered radioactive materials (source, byproduct, and special nuclear materials).
- Respondents sued seeking declaratory and injunctive relief, arguing the FWPCA’s definition of “pollutant,” which includes “radioactive materials,” required EPA regulation of those discharges.
- The district court held the AEA regulatory regime gave the nuclear regulator exclusive authority over discharges of AEA-covered radioactive materials.
- The court of appeals reversed based solely on the FWPCA’s statutory text, concluding EPA must regulate all radioactive materials, including those covered by the AEA.

## Issues

1. Whether a court may refuse to consult legislative history when interpreting a statute whose language appears clear.
2. Whether the FWPCA term “pollutant,” which includes “radioactive materials,” includes source, byproduct, and special nuclear materials regulated under the AEA, thereby requiring EPA regulation of their discharge.

## Decision

- The Supreme Court unanimously reversed the court of appeals and reinstated judgment for EPA.
- The Court held it was error to exclude legislative history from statutory interpretation merely because the text appears clear on a superficial reading.
- Considering legislative history and the preexisting AEA regulatory program, the Court concluded Congress did not intend the FWPCA to alter or duplicate the nuclear regulator’s control over AEA-covered radioactive materials.
- EPA acted within its statutory authority in declining to regulate discharges of source, byproduct, and special nuclear materials under the FWPCA.

## Legal Principles

- Courts may consult legislative history and other interpretive aids when construing statutory language; there is no rule barring such materials solely because the text appears clear on initial review.
- When two federal statutes address related subject matter, statutory terms may be construed to avoid unintended overlap where the later statute’s history shows no intent to disturb an established, comprehensive regulatory scheme.
- The FWPCA’s reference to “radioactive materials” does not, without clear congressional direction, extend EPA permitting authority to AEA-covered source, byproduct, and special nuclear materials regulated under federal nuclear law.

## Conclusion

The Court held that the FWPCA did not require EPA to regulate discharges of AEA-covered radioactive materials from federally licensed nuclear facilities and confirmed that legislative history may be considered to determine statutory meaning and preserve Congress’s intended allocation of regulatory authority.


Train v. Colo. Pub. Int. Rsch. Grp., Inc., 426 U.S. 1 (1976)