Partially resolving a protracted series of inconsistent decisions among the circuits,¹ the Supreme Court on February 23, 1977 held in E.I. DuPont de Nemours & Co. v. Train² that §301 of the Federal Water Pollution Control Act Amendments of 1972 (FWPCA)³ authorizes the Environmental Protection Agency (EPA) to promulgate regulations establishing uniform, single-number, industrywide effluent limitations for existing dischargers, provided some allowance is made for variations in individual plants. The Court ruled that §509⁴ requires challenges to such regulations to be brought in the appropriate court of appeals rather than in the district courts. The Court also held that EPA need not insert a variance provision in new source perfomance standards promulgated under §306⁵ of the Act because Congress intended such standards to be absolute prohibitions from which variances for individual dischargers would be impermissible.

The decision definitively settles a central legal dispute concerning the regulatory structure established by the FWPCA that has dogged EPA's attempts to implement the statute for almost three years, and broadly approves EPA's approach to that implementation. The ruling nevertheless leaves important questions concerning the legality of the limitations unanswered, such as the proper scope of EPA's variance provision for existing sources. Although the Court indicated a clear predisposition to uphold standards and procedures established by EPA in the complex area of pollution control, the DuPont decision is not likely to stem the tide of litigation under the FWPCA currently engulfing the agency.