Document ID: ./input/supremecourt_opinions/opinions/08pdf/07-588.pdf/07-588.pdf
Page Number: 4.0

Cite as:  556 U. S. ____ (2009) 

1 

Opinion of the Court 

NOTICE:  This opinion is subject to formal revision before publication in the
preliminary  print  of  the  United  States  Reports.  Readers  are  requested  to
notify the Reporter of Decisions, Supreme Court of the United States, Wash-
ington,  D. C.  20543,  of  any  typographical  or  other  formal  errors,  in  order
that corrections may be made before the preliminary print goes to press. 

SUPREME COURT OF THE UNITED STATES 

_________________ 

Nos. 07–588, 07–589 and 07–597 
_________________ 

07–588 

ENTERGY CORPORATION, PETITIONER 
v. 
RIVERKEEPER, INC., ET AL. 

07–589 

PSEG FOSSIL LLC, ET AL., PETITIONERS 
v. 
RIVERKEEPER, INC., ET AL. 

07–597 

UTILITY WATER ACT GROUP, PETITIONER 
v. 
RIVERKEEPER, INC., ET AL. 

ON WRITS OF CERTIORARI TO THE UNITED STATES COURT OF 
APPEALS FOR THE SECOND CIRCUIT 

[April 1, 2009]

 JUSTICE SCALIA delivered the opinion of the Court. 
These cases concern a set of regulations adopted by the
Environmental  Protection  Agency  (EPA  or  agency)  under
§316(b)  of  the  Clean  Water  Act,  33  U. S. C.  §1326(b).    69 
Fed.  Reg.  41576  (2004).    Respondents—environmental
groups and various States1—challenged those regulations, 
and the Second Circuit set them aside.  Riverkeeper, Inc. v. 

—————— 

1 The EPA and its Administrator appeared as respondents in support
of petitioners.  See Brief for Federal Parties as Respondents Supporting 
Petitioners.    References  to  “respondents”  throughout  the  opinion  refer 
only to those parties challenging the EPA rules at issue in these cases.