This educational guide is based on the linked primary sources. It is not a Court publication, is not affiliated with the Court, and is not legal advice.
In brief
Overview
The case concerns whether the EPA must approve a state's application to administer the NPDES program when the nine statutory criteria in Section 402(b) are satisfied.
Defenders of Wildlife argue that the EPA must consult with the Fish and Wildlife Service and NOAA under the Endangered Species Act, and that a memorandum of agreement is relevant to the approval process.
- [1] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, p. 4
- [2] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, p. 6
- [3] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, pp. 54–55
- [4] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, p. 20
- [5] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, p. 24
- [6] 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdf, p. 25
Background and question before the Court
According to Justice Kennedy, the Court asked whether the EPA has discretion to withhold approval when the nine statutory criteria are met.
According to Justice Ginsburg, justices also inquired about the applicability of the Endangered Species Act to states such as Texas, Florida, and Maine.
What each side argues
National Association of Home Builders
According to National Association of Home Builders, section 402(b) requires the EPA to approve a state's application unless the state legal authority criteria are not satisfied.
According to National Association of Home Builders, if the nine legal authority criteria are satisfied, EPA cannot withhold approval.
Environmental Protection Agency
EPA argues that pre‑existing ESA regulations require draft permits to be furnished to the Fish and Wildlife Service and NOAA, and that these considerations affect the approval process.
Defenders of Wildlife
According to Respondents, the memorandum of agreement is part of EPA's current practice to consult with the Services when state or tribal applications may affect federally listed species.
According to Respondents, EPA's practice includes consulting with the Services where approval may affect listed species.
What happened at oral argument
What the Court decided
Why it matters
Terms to know
No glossary terms are available for this guide.
Primary sources
Read the source materials on the official site or open the immutable repository copy used for this guide.
- 8991491c93fd40644f8c-r1-ed31cf2bb0959581.pdforal argument transcript
Guide generated September 22, 2026. Automated validation accepted this version.