## Facts

- The Clean Water Act (CWA) authorizes EPA to approve state-administered National Pollutant Discharge Elimination System (NPDES) permit programs if they meet federally prescribed minimum requirements.
- EPA issued regulations setting minimum criteria for state NPDES program approval, addressing (among other elements) public participation in enforcement and the state’s civil-penalty authority.
- On public participation, EPA required states to provide either (a) citizen intervention as of right in state enforcement actions, or (b) assurances that the state will investigate citizen complaints and will not oppose citizen intervention when allowed under state law.
- On penalties, EPA required states to have authority to impose “substantial” civil penalties, with a minimum of at least $5,000 per day per violation, rather than the federal maximum of $25,000 per day.
- NRDC, joined by Citizens for a Better Environment, petitioned for review, arguing that EPA’s regulations were inconsistent with the CWA because they did not require state programs to replicate federal citizen-participation mechanisms and federal maximum penalties.

## Issues

1. Whether EPA acted unlawfully or arbitrarily and capriciously by allowing states to satisfy CWA public-participation requirements through investigatory assurances and non-opposition to intervention, rather than requiring intervention as of right or state analogues to federal citizen suits.
2. Whether EPA acted unlawfully or arbitrarily and capriciously by requiring only a $5,000-per-day minimum civil-penalty authority for state programs, rather than requiring state authority up to the federal $25,000-per-day maximum.

## Decision

- The court denied the petitions for review and largely upheld EPA’s regulations.
- The court held that EPA’s public-participation regulation was permissible because the CWA did not clearly require states to mirror federal citizen-suit or intervention provisions.
- The court held that EPA’s minimum penalty regulation was permissible because the CWA did not require state maximum civil penalties to equal the federal maximum, and EPA’s $5,000-per-day floor was a reasonable policy judgment.
- The court deferred to EPA’s reasonable interpretation of statutory provisions directing the agency to prescribe “minimum requirements” for state program authorization.

## Legal Principles

- When a statute authorizes an agency to set “minimum requirements” and does not clearly require identical state and federal procedures, courts generally defer to the agency’s reasonable construction.
- The CWA’s state-authorization scheme permits variation in state enforcement procedures so long as EPA ensures meaningful public participation and adequate enforcement authority consistent with federal minimum criteria.
- The CWA does not, by its text alone, compel state NPDES programs to replicate federal citizen-suit mechanisms or adopt the federal maximum civil-penalty level; EPA may set a reasonable minimum penalty threshold.

## Conclusion

The D.C. Circuit upheld EPA’s minimum criteria for approving state NPDES programs, concluding that the Clean Water Act leaves EPA discretion to allow flexible public-participation mechanisms and to require substantial, but not federally identical, state civil-penalty authority.


Nat. Res. Def. Council, Inc. v. EPA, 859 F.2d 156 (D.C. Cir. 1988)