## Facts

- The EPA issued a final rule under the Resource Conservation and Recovery Act (RCRA) implementing the Bevill Amendment’s temporary exclusion of certain mining and mineral-processing wastes from Subtitle C hazardous-waste regulation.
- The rule distinguished “mineral processing wastes” from other wastes and determined which specific residuals would remain excluded from Subtitle C.
- EPA used criteria tied to whether a waste was generated in “high volume” and posed “low hazard,” applying quantitative thresholds and risk-related factors.
- Multiple industrial entities petitioned for review, challenging EPA’s statutory interpretation and the adequacy of notice-and-comment procedures.
- Two challenged determinations were prominent: (1) EPA’s conclusion that certain lightweight aggregate residuals did not satisfy the “high volume” criterion, and (2) EPA’s denial of Bevill coverage for Du Pont’s chloride-ilmenite process wastes.

## Issues

1. Whether EPA permissibly interpreted the Bevill Amendment to allow use of “high volume” and “low hazard” criteria, implemented through quantitative measures, to decide which mineral processing wastes remain excluded from RCRA Subtitle C.
2. Whether EPA complied with APA notice-and-comment requirements when it determined that lightweight aggregate residuals failed the “high volume” criterion.
3. Whether EPA provided a reasoned explanation for denying Bevill coverage to Du Pont’s chloride-ilmenite process wastes.

## Decision

- The court largely upheld EPA’s rule and its use of “high volume” and “low hazard” criteria as a permissible construction of the Bevill Amendment.
- The court vacated EPA’s determination as to lightweight aggregate residuals because EPA did not provide adequate notice and opportunity to comment on the basis for finding the wastes not “high volume.”
- The court remanded EPA’s denial of Bevill coverage for Du Pont’s chloride-ilmenite process wastes for a more adequately reasoned explanation.
- Apart from those points, the court found EPA’s approach generally consistent with APA requirements, including the principle that final-rule refinements are permissible when they are a logical outgrowth of the proposal.

## Legal Principles

- When Congress leaves gaps in a statutory scheme like the Bevill Amendment, courts generally defer to reasonable agency interpretations that implement the statute through workable criteria and methods.
- EPA may apply quantitative, risk-informed criteria (including volume and hazard measures) to determine which mineral processing wastes qualify for continued exclusion from RCRA Subtitle C, so long as the approach is reasonable.
- Under the APA, a final rule may reflect additional analysis or refined methodology, but the final position must be a logical outgrowth of the proposal that gave interested parties fair notice and a meaningful chance to comment.
- Agency action is arbitrary and capricious when the agency fails to provide a reasoned explanation connecting the record and its criteria to the decision for a particular waste stream; the usual remedy is remand for further explanation.

## Conclusion

The D.C. Circuit upheld EPA’s general framework for determining Bevill-exempt mineral processing wastes using “high volume” and “low hazard” criteria, but set aside EPA’s lightweight-aggregate determination for defective notice and required EPA to better explain its denial of Bevill coverage for Du Pont’s chloride-ilmenite process wastes.


Solite Corp. v. EPA, 952 F.2d 473 (D.C. Cir. 1991)