Opinion ID: 796659
Heading Depth: 3
Heading Rank: 2

Heading: Definition of Adverse Environmental Impact

Text: 121 In the Phase II Rule, as in the Phase I Rule, the EPA has interpreted the statutory directive of section 316(b) to minimize adverse environmental impact (AEI) to require the reduction of the number of aquatic organisms lost as a result of water withdrawals associated with cooling water intake structures. 69 Fed.Reg. at 41,586. This interpretation reflects the fact that section 316(b) is a somewhat unusual provision of the CWA in that it governs the environmental effects of large scale withdrawals from waters of the United States rather than the release of pollutants into receiving water. As did the industry petitioners in Riverkeeper I, PSEG argues that the EPA arbitrarily defined AEI to include any loss of or harm to aquatic organisms due to impingement mortality and entrainment rather than only more severe population-level effects. It contends that the EPA has historically focused on the population dynamics of aquatic organisms and the fact that many of these organisms are density dependent, i.e., they produce large numbers of offspring, only a few of which survive to adulthood. 34 On the theory that the vast majority of entrained organisms would have died of natural causes in any event, PSEG argues that reduction of impingement mortality and entrainment will have only a marginal positive environmental impact. 35 PSEG contends that because the Agency has changed course from its longstanding interpretation of AEI without giving a clear and reasoned justification for its decision, the EPA's Rule is entitled to less deference than it otherwise would receive. PSEG also argues that the Phase II Rule's exclusion from the entrainment-reduction requirement of facilities withdrawing small amounts of water, facilities withdrawing water from lakes other than the Great Lakes, and facilities that have a small capacity utilization rate undercuts the EPA's determination that impingement mortality and entrainment are per se adverse environmental impacts. We are not persuaded by PSEG's arguments. 122 We agree with the EPA that the Phase II Rule is based on substantially the same record evidence of impingement mortality and entrainment relied upon in promulgating the Phase I Rule and that we rejected substantially the same arguments advanced here by the industry petitioners in Riverkeeper I, 358 F.3d at 197 (The EPA considered all of the factors that UWAG now raises, and we are inclined to defer to the EPA's judgment of how best to define and minimize `adverse environmental impact.' (internal footnote omitted)). Riverkeeper I thus controls this issue. 123 In Riverkeeper I, we rejected the arguments that some species are nuisances and require eradication, that other species respond to population losses by increasing their reproduction, and that removing large numbers of aquatic organisms from waterbodies is not in and of itself an adverse impact. 358 F.3d at 196. We specifically rejected the view that the EPA should only have sought to regulate impingement and entrainment where they have deleterious effects on the overall fish and shellfish populations in the ecosystem, which can only be determined through a case-by-case, site-specific regulatory regime. Id. We emphasized that the EPA's focus on the number of organisms killed or injured by cooling water intake structures is eminently reasonable. Id. We reiterated that Congress had rejected a regulatory approach that relies on water quality standards, analogizing the argument pressed there as urging what is essentially a water quality standard that focuses on fish populations and consequential environmental harm. 36 Id. at 196-97. Given that the record evidence on this issue has not changed in any meaningful way since the Phase I rulemaking, we are both persuaded and bound by our statements on this issue in Riverkeeper I. 124 Were we considering the issue in the first instance, however, we would be inclined to defer to the EPA's judgment in any event. The EPA explained that it has set performance standards for minimizing adverse environmental impact based on a relatively easy to measure and certain metric — reduction of impingement mortality and entrainment. 69 Fed.Reg. at 41,600. It explained further that it chose this approach because impingement and entrainment are primary, harmful environmental effects that can be reduced through the use of specific technologies and stated that where other impacts at the population, community, and ecosystem levels exist, these will also be reduced by reducing impingement and mortality. Id. We see no reason to second-guess this judgment, given the Agency's consideration of the various environmental consequences of cooling water intake structures. See Nat'l Wildlife Fed'n, 286 F.3d at 570 (noting that courts afford the EPA considerable discretion to weigh and balance various factors in determining how to establish performance standards). 37