Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 22.0

16 

WEST VIRGINIA v. EPA 

Opinion of the Court 

could  not  reasonably  be  expected  to  recur.”  Parents  In-
volved in Community Schools v. Seattle School Dist. No. 1, 
551 U. S. 701, 719 (2007).  Here the Government “nowhere 
suggests that if this litigation is resolved in its favor it will
not”  reimpose  emissions  limits  predicated  on  generation 
shifting; indeed, it “vigorously defends” the legality of such 
an  approach.  Ibid.  We  do  not  dismiss  a  case  as  moot  in 
such circumstances.  See City of Mesquite v. Aladdin’s Cas-
tle, Inc., 455 U. S. 283, 288–289 (1982).  The case thus re-
mains justiciable, and we may turn to the merits. 

III 
A 
In devising emissions limits for power plants, EPA first
“determines” the “best system of emission reduction” that—
taking into account cost, health, and other factors—it finds
“has  been  adequately  demonstrated.” 
42  U. S. C. 
§7411(a)(1).  The  Agency  then  quantifies  “the  degree  of 
emission limitation achievable” if that best system were ap-
plied  to  the  covered  source.  Ibid.;  see  also  80  Fed.  Reg.  
64719.  The BSER, therefore, “is the central determination 
that  the  EPA  must  make  in  formulating  [its  emission]
guidelines”  under  Section  111.    Id.,  at  64723.  The  issue 
here  is  whether  restructuring  the  Nation’s  overall  mix  of 
electricity  generation,  to  transition  from  38%  coal  to  27%
coal by 2030, can be the “best system of emission reduction” 
within the meaning of Section 111. 

“It is a fundamental canon of statutory construction that
the  words  of  a  statute  must  be  read  in  their  context  and 
with a view to their place in the overall statutory scheme.” 
Davis  v.  Michigan  Dept.  of  Treasury,  489  U. S.  803,  809 
(1989).  Where the statute at issue is one that confers au-
thority upon an administrative agency, that inquiry must 
be “shaped, at least in some measure, by the nature of the
question  presented”—whether  Congress  in  fact  meant  to 
confer the power the agency has asserted.  FDA v. Brown &