## Facts

- Environmental organizations challenged four U.S. Army Corps of Engineers Clean Water Act (CWA) § 404 permits authorizing discharges of dredged or fill material into West Virginia streams for mountaintop removal mining operations using valley fills and related sediment-control structures.
- Valley fills buried intermittent and perennial headwater streams; mine-water and sediment were routed through engineered drainage features to sediment ponds for treatment and stability.
- Plaintiffs alleged the Corps violated the CWA, NEPA, and the APA by inadequately analyzing alternatives, impacts, mitigation, and water-quality compliance and by improperly limiting environmental review to jurisdictional waters.
- Plaintiffs also contested the Corps’ treatment of stream segments between valley fills and downstream sediment ponds (and the ponds themselves) as non-jurisdictional under a “waste treatment system” exclusion.
- The district court rescinded the permits, enjoined activities under them, declared the connecting stream segments “waters of the United States,” and remanded to the Corps.
- The Corps and intervening coal companies appealed.

## Issues

1. Whether the Corps’ issuance of § 404 permits for valley fills and associated sediment-control features was arbitrary or capricious under the APA, including compliance with the § 404(b)(1) Guidelines.
2. Whether NEPA required the Corps to evaluate environmental effects of the entire mining operations rather than limiting analysis to effects tied to the permitted discharges into jurisdictional waters.
3. Whether the stream segments connecting valley fills to sediment ponds, and the ponds themselves, were “waters of the United States” or instead fell within the regulatory “waste treatment system” exclusion.
4. Whether the Corps unlawfully relied on professional judgment rather than a full functional assessment methodology in evaluating aquatic impacts and mitigation.

## Decision

- The Fourth Circuit reversed the district court, vacated the injunction and permit rescissions, and remanded.
- The court held the Corps did not act arbitrarily or capriciously in issuing the § 404 permits and reasonably applied the § 404(b)(1) Guidelines, including its approach to mitigation and impact evaluation.
- The court held the Corps reasonably limited its NEPA review to impacts with a reasonably close causal relationship to the § 404-permitted discharges and within the Corps’ regulatory authority.
- The court reversed the declaration that the connecting stream segments were “waters of the United States,” holding the Corps reasonably treated the sediment ponds and connecting channels as part of an excluded waste treatment system.

## Legal Principles

- Under the APA, courts uphold agency action unless it is arbitrary, capricious, or contrary to law; courts may not substitute their judgment for an agency’s on technical matters supported by the record.
- NEPA requires a “hard look” at environmental consequences, but the scope of analysis is bounded by the agency’s statutory authority and by effects closely tied to the agency action.
- For § 404 permitting, the Corps may focus NEPA analysis on direct and indirect impacts of the discharge into jurisdictional waters and related aquatic-resource effects, including mitigation and cumulative effects within its purview.
- The Corps may rely on reasonable professional judgment in ecological evaluations and mitigation planning when comprehensive quantitative functional assessment methods are unavailable or not required by regulation.
- The regulatory definition of “waters of the United States” may exclude qualifying waste treatment systems designed to meet CWA requirements; engineered treatment ponds and associated conveyances may be treated as a single excluded system when reasonably supported by the record.

## Conclusion

The Fourth Circuit reinstated the Corps’ mountaintop-mining § 404 permits, holding that the Corps reasonably confined NEPA review to effects tied to the permitted discharges, permissibly relied on technical judgment for impact and mitigation assessments, and reasonably treated sediment ponds and connecting channels as an excluded waste treatment system rather than separate jurisdictional waters.


Ohio Valley Envtl. Coal. v. Aracoma Coal Co., 556 F.3d 177 (4th Cir. 2009)