## Facts

- Ships take on and discharge ballast water for stability, releasing large volumes into U.S. waters annually.
- Ballast water can contain non-native organisms, eggs, larvae, sediment, and pollutants that may be introduced into new waterbodies and form invasive populations.
- The Clean Water Act (CWA) generally prohibits pollutant discharges without authorization under the National Pollutant Discharge Elimination System (NPDES).
- EPA issued a 2013 Vessel General Permit (VGP) under CWA § 402(a) to regulate, among other things, ballast-water discharges from vessels.
- The VGP set numeric ballast-water discharge standards that largely tracked the International Maritime Organization (IMO) ballast-water convention standards.
- Environmental organizations petitioned for review, asserting that EPA failed to set technology-based limits reflecting more protective treatment capabilities, inadequately considered shore-based treatment and other alternatives, and adopted insufficient monitoring and enforcement requirements.
- Industry groups intervened in support of EPA.

## Issues

1. Whether EPA acted arbitrarily and capriciously under the Administrative Procedure Act (APA) and contrary to the CWA by setting ballast-water numeric discharge limits that effectively mirrored the IMO standard without adequate justification under the CWA’s technology-based requirements.
2. Whether EPA unlawfully failed to meaningfully consider shore-based treatment and other potentially more protective technological options.
3. Whether the VGP’s monitoring, reporting, enforcement, and best management practice provisions were arbitrary and capricious or inconsistent with the CWA.
4. What remedy was appropriate if portions of the VGP were unlawful.

## Decision

- The Second Circuit granted the petitions in part, denied them in part, and remanded to EPA for further proceedings.
- The court held EPA’s 2013 VGP was arbitrary and capricious in several respects, including aspects of the ballast-water effluent limitation analysis.
- The court faulted EPA for insufficiently explaining why more stringent numeric limits were not required in light of evidence of more effective treatment technology.
- The court held EPA inadequately considered shore-based treatment and certain alternatives, reflecting a failure to address important aspects of the regulatory problem.
- The court upheld some VGP provisions where EPA’s explanations were supported by the technical record, but vacated or required reconsideration of specific deficient portions.
- In crafting relief, the court accounted for the need for regulatory continuity while EPA developed a lawful replacement approach.

## Legal Principles

- Under the CWA’s technology-based framework, EPA must set effluent limitations based on required statutory criteria (including “best available technology economically achievable,” as applicable) and must explain the technical and economic basis for the chosen limits.
- APA arbitrary-and-capricious review requires reasoned decision-making; an agency must consider important aspects of the problem, engage with significant contrary evidence, and provide an adequate explanation connecting the record to the result.
- Reliance on an international benchmark may be a policy consideration, but it does not satisfy the CWA absent an independent determination that the benchmark meets the statute’s technology-based requirements.
- Courts will defer to technical judgments supported by the record, but will set aside agency action where explanations are conclusory, incomplete, or ignore material evidence.

## Conclusion

The Second Circuit required EPA to reexamine key elements of its ballast-water permitting regime, holding that EPA could not justify numeric discharge limits by largely tracking an international standard without a reasoned, record-based showing that the limits satisfied the CWA’s technology-based mandates, and remanded for EPA to correct identified deficiencies while maintaining necessary regulatory coverage.


Nat. Res. Def. Council v. U.S. Env’t Prot. Agency, 808 F.3d 556 (2d Cir. 2015)