## Facts

- The Garcia River in California failed to meet state water quality standards due to sedimentation and temperature impacts attributed to land-disturbing activities, including logging (nonpoint sources).
- Under Clean Water Act (CWA) § 303(d), EPA required California to list the Garcia River as water-quality-limited and to establish total maximum daily loads (TMDLs) for relevant pollutants.
- After California did not develop a TMDL by the statutory deadline, EPA promulgated a Garcia River TMDL setting an overall pollutant load and allocating loads among source categories.
- Landowners and agricultural and forestry associations asserted that, as a practical matter, compliance efforts led state and local authorities to impose added restrictions on timber harvesting and related land-use practices.
- Plaintiffs sued EPA in federal district court, contending EPA lacked statutory authority to require listing and TMDLs for waters impaired only by nonpoint sources.
- The district court granted summary judgment for EPA; plaintiffs appealed.

## Issues

1. Whether CWA § 303(d) authorizes EPA to require states to list waters and prepare (or accept EPA-prepared) TMDLs when water quality impairment is caused solely by nonpoint source pollution.
2. Whether the reference to “effluent limitations” in § 303(d)(1)(A) limits the TMDL program to waters impaired by point sources.
3. Whether EPA’s interpretation of § 303(d) is entitled to Chevron deference.

## Decision

- The Ninth Circuit affirmed summary judgment for EPA.
- The court held EPA may require listing and TMDLs for waters impaired solely by nonpoint sources.
- The court concluded the statutory reference to “effluent limitations” operates as a trigger for additional water-quality-based measures, not as a restriction to point-source-impaired waters.
- Applying Chevron, the court found the statute ambiguous on the disputed scope and upheld EPA’s interpretation as reasonable and consistent with the Act’s objective.
- The court rejected federalism and land-use objections, emphasizing that TMDLs are planning tools and do not directly regulate nonpoint sources or compel particular state implementation measures.

## Legal Principles

- CWA § 303(d) authorizes listing and TMDL development for waters failing to meet water quality standards, including waters impaired by nonpoint sources alone.
- The phrase “effluent limitations … not stringent enough” in § 303(d)(1)(A) identifies when water-quality-based planning is required; it does not confine § 303(d) to point-source pollution.
- TMDLs function primarily as informational and planning instruments that quantify total allowable pollutant loadings and allocate loads among sources; they do not, by themselves, impose enforceable controls on nonpoint sources.
- Under Chevron, when § 303(d)’s scope is not unambiguous, EPA’s reasonable interpretation extending TMDLs to nonpoint-source-impaired waters warrants deference.
- The CWA’s structure combines technology-based limits (primarily for point sources) with water-quality-based tools; § 303(d) serves the latter role when standards are not met even with technology-based controls.

## Conclusion

The Ninth Circuit upheld EPA’s authority under CWA § 303(d) to require listing and establish TMDLs for waters that do not meet water quality standards due solely to nonpoint source pollution, treating TMDLs as a federal planning framework implemented through state choices rather than direct federal land-use regulation.


Pronsolino v. Nastri, 291 F.3d 1123 (9th Cir. 2002)