As required by the Clean Water Act, the EPA issued standards for discharges from hundreds of sources. Despite the standards, the EPA issued on a case-by-case basis variances to some water polluters, allowing them to exceed the discharge standards. The Natural Resource Defense Council sued to oppose such variances; the Chemical Manufacturers Association defended the variances. Who won?
[Chemical Manufacturers Assn. v. NRDC, 470 U.S. 116 (1985)]