## Facts

- EPA issued a final rule under the Safe Drinking Water Act (SDWA) regulating radionuclides in public drinking water systems.
- The rule retained existing maximum contaminant levels (MCLs) for radium-226/radium-228 and beta/photon emitters, and adopted a new MCL and maximum contaminant level goal (MCLG) for naturally occurring uranium, along with monitoring requirements.
- The City of Waukesha and other petitioners claimed the rule would impose substantial compliance costs on public water systems and affected industries.
- Petitioners (a municipality and water customer, two trade associations, and an advocacy group) filed consolidated petitions for review in the D.C. Circuit challenging the rule under the SDWA and the Administrative Procedure Act (APA).
- EPA disputed standing for some petitioners and defended the rulemaking record on statutory and APA grounds.

## Issues

1. Whether each petitioner had Article III standing to seek review of EPA’s radionuclide rule.
2. Whether EPA’s SDWA cost–benefit analysis for the new uranium MCL was legally adequate, including whether EPA had to assess costs and benefits arising in non-SDWA programs such as CERCLA cleanups.
3. Whether EPA satisfied the SDWA requirement to rely on the “best available, peer-reviewed science” in setting radionuclide standards.
4. Whether EPA adequately responded to significant comments as required by the APA.

## Decision

- The court held that all petitioners except Radiation, Science & Health, Inc. (RSH) had standing.
- The court dismissed RSH’s petition for lack of standing due to failure to show a concrete injury traceable to the rule.
- On the merits, the court denied the remaining petitions for review and upheld the radionuclide rule in full.
- The court rejected the claim that the SDWA required EPA’s uranium cost–benefit analysis to incorporate costs and benefits from CERCLA hazardous-waste remediation contexts.
- The court found EPA’s scientific judgments and responses to comments sufficient under deferential APA review.

## Legal Principles

- Regulated entities may establish standing through concrete compliance-cost injury; trade associations may establish associational standing based on injuries to members; a generalized advocacy interest without a cognizable injury is insufficient for Article III standing.
- SDWA cost–benefit obligations for a new drinking-water contaminant focus on public water system compliance; absent clear statutory direction, EPA need not incorporate costs and benefits from other statutory schemes into the SDWA analysis.
- Courts review EPA’s technical and scientific determinations under arbitrary-and-capricious standards and do not reweigh competing scientific models when the agency reasonably explains its choice and grounds it in peer-reviewed materials.
- Under APA notice-and-comment requirements, EPA must address significant comments; adequate explanations in the rulemaking record satisfy this obligation.

## Conclusion

The D.C. Circuit dismissed one petitioner for lack of standing but otherwise upheld EPA’s SDWA radionuclide drinking-water regulations, concluding EPA reasonably limited its cost–benefit analysis to the drinking-water setting, relied on acceptable peer-reviewed science, and adequately responded to significant comments.


City of Waukesha v. EPA, 320 F.3d 228 (D.C. Cir. 2003)