ABSTRACT
In its plain and ordinary meaning, the phrase “adverse environmental impact” refers to any negative effect on any aspect of the environment, and clearly encompasses nontrivial aquatic mortality. The dictionary definitions of each word in the phrase bear that out. “Adverse” means “unfavorable or antagonistic”18. “Environment” means “the air, water, minerals, organisms and all other external factors surrounding and affecting a given organism at any time”19. “Impact” means “influence; effect”20. Thus, anything that affects the environment in a negative way has an adverse environmental impact. In a gambit to create an additional technical and procedural hurdle to effective regulation, industry insists that permitting agencies must pointedly define AEI at some threshold level of ecological damage for each individual application21. The contention is inconsistent with the structure of the CWA and the statutory language. There is no need or sound reason to precisely define a level of acceptable impact, or ascertain the level of unnecessary killing before destabilization of population, to implement the statutory requirement to “minimize adverse environmental impact”22. This unremarkable and (in most cases) relatively simple injunction is directly analogous to the modifier “control” for discharge standards under section 306 of the Act. Both terms define the respective purpose of the technology (in each case required to be the best available): to control pollutant discharges under section 306 and to minimize ecological damage due to coolingwater withdrawals under section 316(b). In other words, they supply the answer to the question, “Best technology for what?”, which is basic to the meaning of the respective sections. There is nothing in the statutory language that requires a separate determination of some supposed level of AEI, or a self-
18 Random House Webster’s College Dictionary, 1999. In the environmental law context, “adverse” is often used as the opposite of “beneficial.”
