Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 67

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

11 

KAGAN, J., dissenting 

91 Stat. 700 (emphasis added).  But for existing sources, the
word “technological” was struck out: EPA could select the
“best system of continuous emission reduction.”  Ibid.  The 
House  Report  emphasized  Congress’s  deliberate  choice: 
Whereas the standards set for new sources were to be based 
on “the best technological” controls, the “standards adopted
for existing sources” were “to be based on available means 
of emission control (not necessarily technological).”  H.  R. 
Rep. No. 95–564, p. 129 (1977).  The Report did not further
explain  the  distinction.  But  presumably  Congress  gave
EPA more flexibility over existing plants because imposing
technological  controls  on  old  facilities  is  often  not  cost- 
effective.2  Thirteen years later, Congress followed up by de-
leting from Section 111 the technological limitation apply-
ing  to  new  facilities.  See  Clean  Air  Act  Amendments  of 
1990, §403(a), 104 Stat. 2631.  Once again, then, Congress
faced a choice: confine EPA to technological controls, or not.
And replicating its earlier action for existing sources, Con-
gress chose not.

The  majority  breezes  past  that  congressional  choice  on
the  ground  that  today’s  opinion  does  not  resolve  whether 
EPA can regulate in some non-technological ways; instead,
the opinion says only that the Clean Power Plan goes too 
—————— 

2 The majority offers a theory for why Congress insisted on a techno-
logical  system  for  new  sources:  It  was,  the  majority  says,  to  prevent 
EPA’s  use  of  a  particular  kind  of  technological  system  (involving  fuel 
switching) to achieve emissions reductions.  See ante, at 22, n. 2, 23.  To 
begin with: I don’t see how requiring EPA to select among technological
systems precludes it from picking what the majority agrees is one such 
measure.  See ante, at 4, 22, n. 2, 22–23.  But more important, I can’t see 
why  the  majority’s  explanation  matters.    Let’s  assume  the  majority  is
right about Congress’s motive. The key point remains the same: What-
ever that motive, Congress’s instruction to use technological systems ap-
plied only to new sources, and not to existing ones.  As to the latter, Con-
gress allowed EPA more latitude: The Agency could use technological or 
non-technological methods, as it preferred.  That distinction is what cre-
ates  interpretive  difficulties  for  the  majority—again,  no  matter  why  it 
arose.