Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 7.0

Cite as:  597 U. S. ____ (2022) 

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. 20–1530, 20–1531, 20–1778 and 20–1780 
_________________ 

20–1530 

WEST VIRGINIA, ET AL., PETITIONERS 
v. 
ENVIRONMENTAL PROTECTION AGENCY, ET AL. 

THE NORTH AMERICAN COAL CORPORATION, 
PETITIONER 
v. 
ENVIRONMENTAL PROTECTION AGENCY, ET AL. 

20–1531 

WESTMORELAND MINING HOLDINGS LLC, 
PETITIONER 
v. 
ENVIRONMENTAL PROTECTION AGENCY, ET AL. 

20–1778 

20–1780 

NORTH DAKOTA, PETITIONER 
v. 
ENVIRONMENTAL PROTECTION AGENCY, ET AL. 

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

[June 30, 2022] 

CHIEF  JUSTICE  ROBERTS  delivered  the  opinion  of  the 

Court. 

The Clean Air Act authorizes the Environmental Protec-
tion Agency to regulate power plants by setting a “standard
of performance” for their emission of certain pollutants into