Document ID: ./input/supremecourt_opinions/opinions/08pdf/07-588.pdf/07-588.pdf
Page Number: 35

6 

ENTERGY CORP. v. RIVERKEEPER, INC. 

STEVENS, J., dissenting 

dard  delivers  a  clear  command:  To  minimize  the  adverse 
environmental  impact  of  water  intake  structures,  the 
EPA  must  require  industry  to  adopt  the  best  technology
available. 

Based  largely  on  the  observation  that  §316(b)’s  text
offers little guidance and therefore delegates some amount 
of  gap-filling  authority  to  the  EPA,  the  Court  concludes 
that  the  Agency  has  discretion  to  rely  on  cost-benefit
analysis.  See ante, at 11–12.  The Court assumes that, by 
not specifying how the EPA is to determine BTA, Congress 
intended  to  give  considerable  discretion  to  the  EPA  to
decide  how  to  proceed.  Silence,  in  the  majority’s  view, 
represents  ambiguity  and  an  invitation  for  the  Agency  to
decide for itself which factors should govern its regulatory
approach.

The  appropriate  analysis  requires  full  consideration  of 
the  CWA’s  structure  and  legislative  history  to  determine
whether Congress contemplated cost-benefit analysis and,
if  so,  under  what  circumstances  it  directed  the  EPA  to 
utilize  it.  This  approach  reveals  that  Congress  granted
the  EPA  authority  to  use  cost-benefit  analysis  in  some
contexts  but  not  others,  and  that  Congress  intend  to  con-
trol,  not  delegate,  when  cost-benefit  analysis  should  be
used.  See  Chevron  U. S. A.  Inc.  v.  Natural  Resources 
Defense Council, Inc., 467 U. S. 837, 842–843 (1984).5 

—————— 

sions  in  §316(b)  merely  requires  any  rule  promulgated  under  those 
provisions,  when  applied  to  a  point  source  with  a  water  intake  struc-
ture, to incorporate §316(b) standards. 

5 The majority announces at the outset that the EPA’s reading of the 
BTA  standard  “governs  if  it  is  a  reasonable  interpretation  of  the  stat-
ute—not  necessarily  the  only  possible  interpretation,  nor  even  the 
interpretation deemed most reasonable by the courts.”  Ante, at 7.  This 
observation  is  puzzling  in  light  of  the  commonly  understood  practice
that,  as  a  first  step,  we  ask  “whether  Congress  has  directly  spoken  to 
the precise question at issue.”  Chevron, 467 U. S., at 842.  Only later, if 
Congress’ intent is not clear, do we consider the reasonableness of  the 
agency’s  action.  Id.,  at  843.    Assuming  ambiguity  and  moving  to  the