## Facts

- The Clean Water Act (CWA) § 304(l) requires states to submit three lists of waters not expected to meet water quality standards, categorized by the source/type of pollutants: A(i), A(ii), and B.
- Section 304(l) also requires states to identify point sources discharging listed toxic pollutants into waters “on such lists” and to develop “individual control strategies” (ICSs) for those sources, subject to EPA oversight.
- EPA issued implementing regulations interpreting § 304(l)’s identification and ICS requirements to apply only to waters on the B list, excluding waters on the A(i) and A(ii) lists even if those waters receive toxic discharges from point sources.
- Natural Resources Defense Council, Inc. petitioned for direct review in the Ninth Circuit, challenging the regulations as inconsistent with § 304(l).

## Issues

1. Whether CWA § 304(l) requires states to identify point sources discharging toxic pollutants and develop ICSs only for B-list waters, or also for A(i) and A(ii) list waters that receive toxic point-source discharges.
2. Whether EPA’s B-list-only interpretation is entitled to deference under Chevron.

## Decision

- The court granted the petition in part and set aside the regulation to the extent it limited the § 304(l) identification and ICS requirements to B-list waters.
- The court held that § 304(l) unambiguously applies the identification and ICS requirements to waters on all three § 304(l) lists.
- Because Congress spoke clearly, EPA was not entitled to Chevron deference for a contrary interpretation.
- The matter was remanded to EPA for proceedings consistent with the court’s interpretation.

## Legal Principles

- Under Chevron step one, an agency interpretation must be rejected when statutory text directly addresses the precise question at issue.
- Statutory references to “lists” and “such lists” in § 304(l) require giving effect to the plural term, absent limiting language restricting obligations to a single list.
- CWA § 304(l)’s point-source identification and ICS requirements apply to any waters included on the § 304(l) lists that receive toxic pollutant discharges from point sources, even if the water body is listed for other reasons.

## Conclusion

The Ninth Circuit invalidated EPA’s attempt to confine § 304(l)’s point-source toxic identification and individual control strategy program to B-list waters, holding that the statute’s text requires the program to reach toxic point-source discharges to waters on any of the § 304(l) lists.


Natural Resources Defense Council, Inc. v. EPA, 915 F.2d 1314 (9th Cir. 1990)