## Facts

- Congress amended RCRA in 1984 to phase out land disposal of certain hazardous wastes by requiring EPA to issue land disposal restrictions (LDRs) and treatment standards, including standards “achievable by the best demonstrated available technology” (BDAT) for specified wastes.
- EPA initially proposed “health-screening” (risk-based) concentration levels for solvents and dioxin-containing wastes.
- After notice and comment and congressional criticism that the statute required BDAT-based standards, EPA issued a final LDR rule for solvents and dioxins grounded in BDAT performance data.
- Multiple petitioners—including environmental organizations, trade associations, and regulated entities—filed consolidated petitions for review challenging EPA’s final rule on statutory and administrative-law grounds.

## Issues

1. Whether EPA’s BDAT-based treatment standards for solvents and dioxin-containing wastes were a permissible construction of RCRA as amended by HSWA.
2. Whether EPA’s change from the proposed health-based approach to a BDAT-based framework was adequately explained and supported, or was arbitrary and capricious.
3. Whether particular treatment levels, waste categorizations, and technical assumptions in the rule were adequately justified.

## Decision

- The court denied the petitions in large part, upholding EPA’s core BDAT-based structure and most treatment standards.
- The court held that EPA’s interpretation implementing BDAT-based standards was reasonable under the statute and entitled to deference.
- The court found EPA sufficiently explained the shift away from the health-based proposal, relying on statutory fit and implementation concerns reflected in the record.
- The court granted the petitions in part and remanded limited portions of the rule for further explanation or reconsideration, without vacating the overall regulatory framework.
- A separate opinion concurred in part and in the result, expressing reservations about aspects of EPA’s reasoning while agreeing that only limited remands were warranted.

## Legal Principles

- When a statute commits implementation details to an agency and the agency adopts a reasonable construction, reviewing courts generally defer to that interpretation.
- An agency may change policy positions during rulemaking, but must provide a reasoned explanation grounded in the statute and the administrative record.
- Courts give substantial deference to an agency’s technical judgments and data-driven methodologies in complex regulatory settings, while still requiring a rational explanation for key choices.
- Under RCRA’s LDR program, EPA may set stringent, technology-forcing treatment standards derived from demonstrated performance of well-operated technologies, including conservative assumptions, so long as adequately explained.
- Remand without vacatur is appropriate where discrete deficiencies in explanation can be cured without dismantling the broader rule.

## Conclusion

The D.C. Circuit largely sustained EPA’s solvents-and-dioxins LDR rule as a lawful, BDAT-based implementation of RCRA/HSWA, rejecting most statutory and arbitrariness challenges while remanding only limited provisions for additional justification.


Hazardous Waste Treatment Council v. U.S. Environmental Protection Agency, 886 F.2d 355 (D.C. Cir. 1989)