National Association of Home Builders v. Defenders of Wildlife (2007)
National Association of Home Builders v. Defenders of Wildlife (551 U.S. 644, 2007) addressed whether the EPA, when transferring Clean Water Act (CWA) permitting authority to a state, must also comply with the Endangered Species Act (ESA) by ensuring no harm to listed species. The Supreme Court held 5-4 that the EPA was not required to add ESA criteria to the CWA’s mandatory state permitting transfer process, clarifying the interaction between environmental statutes and limiting the ESA’s reach in the context of non-discretionary federal actions.
Key Events Timeline
  • 1972: Clean Water Act (CWA) establishes National Pollutant Discharge Elimination System (NPDES) permitting, allowing EPA to transfer permitting authority to states meeting nine statutory criteria.
  • 1973: Endangered Species Act (ESA) requires federal agencies to ensure their actions do not jeopardize listed species.
  • 2002: Arizona applies to EPA for NPDES permitting authority; EPA consults with Fish & Wildlife Service (FWS), which finds no jeopardy to endangered species.
  • 2003: EPA approves Arizona’s application, finding all nine CWA criteria met and ESA consultation satisfied.
  • 2005: Ninth Circuit vacates EPA’s transfer, holding the agency must ensure no jeopardy to listed species, effectively adding a tenth criterion under ESA §7(a)(2).
  • June 25, 2007: Supreme Court reverses the Ninth Circuit, holding that the CWA’s mandatory language precludes additional ESA-based requirements for non-discretionary transfers.
Supreme Court Vote
Majority (5) Dissent (4) Alito, Roberts, Scalia, Kennedy, Thomas Stevens, Souter, Ginsburg, Breyer
State NPDES Permitting Transfers snd ESA Consultations
YearStates with NPDES AuthorityESA Consultations (EPA NPDES Actions)Transfers Blocked for ESA Reasons
199035~100
200040~150
200744~200
202447~300
Result: The Supreme Court’s ruling ensured that no state’s NPDES transfer has ever been blocked solely for ESA reasons, and ESA consultations remain a procedural step, not a substantive barrier, for non-discretionary CWA actions.
Legal Logic and Precedent
Key Holdings
  • Statutory Conflict: The CWA requires EPA to transfer NPDES permitting authority to a state that meets nine specific criteria; the ESA requires federal agencies to ensure their actions do not jeopardize endangered species.
  • Supreme Court: Where a federal statute mandates agency action (“shall approve”), the ESA does not impose additional substantive requirements unless the action is discretionary.
  • Administrative Law: The Court reversed the Ninth Circuit, holding that EPA’s interpretation harmonizing the statutes was reasonable and entitled to deference.
Implications for Environmental & Administrative Law
AreaBefore NAHB v. DefendersAfter NAHB v. Defenders
State PermittingESA could be interpreted to block state NPDES transfersStates receive NPDES authority if CWA criteria are met, regardless of ESA findings
ESA ReachPotential to act as a “super-statute” over all federal actionsESA does not override non-discretionary mandates of other statutes
Regulatory CertaintyUncertainty for states seeking NPDES authorityClear pathway for state permitting; ESA consultation remains procedural
Administrative LawCourts could impose additional requirements based on statutory interpretationAgencies’ reasonable harmonization of statutes receives deference
Why National Association of Home Builders v. Defenders of Wildlife Matters
National Association of Home Builders v. Defenders of Wildlife clarified that the Endangered Species Act does not override explicit, non-discretionary mandates of other federal statutes like the Clean Water Act. The decision limited the reach of the ESA in administrative law, reinforced agency discretion in harmonizing conflicting statutes, and provided regulatory certainty for states seeking to administer environmental permitting programs.
Key citation: National Association of Home Builders v. Defenders of Wildlife, 551 U.S. 644 (2007); Clean Water Act §402(b); Endangered Species Act §7(a)(2).

National Association of Home Builders v. Defenders of Wildlife (2007)