## Facts

- The U.S. Army Corps of Engineers and the EPA administer Clean Water Act (CWA) § 404 permitting for discharges of dredged or fill material into waters of the United States.
- A 1986 regulation defined “discharge of dredged material” as an “addition” but excluded de minimis, incidental soil movement during normal dredging.
- In 1993, the agencies issued the “Tulloch Rule,” redefining “discharge of dredged material” to include “any redeposit” of dredged or excavated material, including incidental fallback into the area from which it was removed.
- Trade associations representing entities engaged in dredging and excavation challenged the rule, arguing incidental fallback is not an “addition” of a pollutant to navigable waters.
- The district court granted summary judgment to the challengers, declared the Tulloch Rule unlawful, and enjoined its enforcement nationwide.
- The Corps, EPA, and environmental intervenors appealed.

## Issues

1. Whether incidental fallback during dredging or excavation constitutes an “addition of any pollutant to navigable waters,” and thus a “discharge of a pollutant,” under the CWA.
2. Whether the Corps and EPA exceeded their statutory authority by defining “discharge of dredged material” to include any redeposit, including incidental fallback.
3. Whether Chevron deference applies to the agencies’ interpretation of “addition” in the CWA definition of discharge.

## Decision

- The D.C. Circuit affirmed the judgment invalidating the Tulloch Rule and affirmed the nationwide injunction.
- The court held that incidental fallback—material removed and then dropped back into substantially the same place—is not an “addition” to navigable waters and therefore is not a regulable discharge under CWA § 404.
- The court rejected Chevron deference because the statutory text unambiguously requires an “addition,” which excludes incidental fallback.
- The court distinguished incidental fallback from other redeposits (such as sidecasting or depositing in a different area), which may constitute an “addition.”
- A concurring opinion stressed that agencies may not extend regulatory jurisdiction beyond statutory limits.

## Legal Principles

- CWA “discharge of a pollutant” requires an “addition” of a pollutant to navigable waters from a point source; activity that results in no net addition falls outside that definition.
- Incidental fallback into substantially the same location from which material was dredged is not an “addition” and cannot be regulated as a § 404 discharge on that basis.
- Chevron deference is unavailable where Congress has directly addressed the precise question and the statutory text is unambiguous.
- Agency interpretations that effectively regulate trivial, ubiquitous soil movement suggest an impermissibly expansive reading of statutory terms.
- Courts may invalidate a rule in its core operation where the rule’s defining expansion exceeds statutory authority, and may uphold nationwide injunctive relief where appropriate to prevent unlawful enforcement.

## Conclusion

The court held that the Clean Water Act’s requirement of an “addition” bars the Corps and EPA from treating incidental fallback as a § 404 “discharge of dredged material,” invalidated the Tulloch Rule as beyond statutory authority, and upheld a nationwide injunction against its enforcement.


Nat'l Mining Ass'n v. U.S. Army Corps of Eng'rs, 145 F.3d 1399 (D.C. Cir. 1998)