430 U.S. 112 (1997)
Petitioners operated chemical manufacturing plants that discharged pollutants into the water and therefore qualified as “point sources” under the Clean Water Act (CWA), enacted in 1972. The EPA promulgated regulations pursuant to the CWA imposing limitations on such discharges. Section 301 of the CWA sets a timetable for effluent limitations (requiring use of “best practicable” technology by 1977 and “best available” technology by 1983), and also allows for variances for individual plants. Section 402 authorizes EPA to issue permits for individual point sources ensuring compliance with Section 301 limitations. Section 306 directs EPA to promulgate regulations establishing national standards of performance for new plants within each category.
Petitioners filed for review of the regulations in the Fourth Circuit Court of Appeals. The Fourth Circuit rejected petitioners’ challenge to EPA’s authority to issue precise, single-number limitations for discharges of pollutants from existing sources, but held that such limitations and new plant standards were only “presumptively applicable” to individual plants.
1. Whether EPA has authority under Section 301 of the CWA to issue industrywide regulations limiting discharges by existing plants.
2. Whether EPA’s new source standards issued under Section 306 of the CWA must allow variances for individual plants.
Rule / Holding
1. The CWA authorizes EPA to set effluent limitations for existing sources of plants through industrywide regulations with allowances made for variances for certain individual plants.
2. The CWA does not provide for variances from EPA’s standards of performance for new point sources.
The statutory language of Section 301 makes it clear that effluent limitations are to be set by regulation and not on an individual basis as permits are issued. Section 301 states that by 1983, “effluent limitations for categories and classes of point sources” are to be achieved which will require “application of the best available technology economically achievable for such category or class.” Such classwide determinations would normally be made through regulation. Although the statute referred to “effluent limitations for point sources” and not categories or classes with respect to the 1977 limitations, nothing elsewhere in the CWA suggests any difference in the mechanism used to impose the 1977 and 1983 limitations. Moreover, petitioner’s view of the CWA would place an “impossible burden” on EPA to give individual consideration to the circumstances of tens of thousands of dischargers applying for permits and make all of these permitting decisions in advance of the 1977 deadline.
With respect to the new source regulations, unlike the Section 301 regulations for existing plants, the CWA contains no variance provision. Moreover, “a variance provision would be inappropriate in a standard that was intended to insure national uniformity and ‘maximum feasible control of new sources.’”