Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-454_4g15.pdf
Page Number: 31

Cite as:  598 U. S. ____ (2023) 

25 

Opinion of the Court 

change.  This freewheeling inquiry provides little notice to 
landowners of their obligations under the CWA.  Facing se-
vere criminal sanctions for even negligent violations, prop-
erty owners are “left ‘to feel their way on a case-by-case ba-
sis.’ ”  Sackett, 566 U. S., at 124 (quoting Rapanos, 547 U. S., 
at 758 (ROBERTS, C. J., concurring)).  Where a penal statute
could sweep so broadly as to render criminal a host of what 
might otherwise be considered ordinary activities, we have
been wary about going beyond what “Congress certainly in-
tended the statute to cover.”  Skilling, 561 U. S., at 404. 

Under these two background principles, the judicial task 
when  interpreting  “the  waters  of  the  United  States”  is  to 
ascertain whether clear congressional authorization exists 
for the EPA’s claimed power.  The EPA’s interpretation falls 
far short of that standard. 

B 

While mustering only a weak textual argument, the EPA 
justifies  its  position  on  two  other  grounds.    It  primarily 
claims that Congress implicitly ratified its interpretation of 
“adjacent” wetlands when it adopted §1344(g)(1).  Thus, it 
argues that “waters of the United States” covers any wet-
lands  that  are  “bordering,  contiguous,  or  neighboring”  to 
covered waters.  88 Fed. Reg. 3143.  The principal opinion
concurring in the judgment adopts the same position.  See 
post,  at  10–12  (KAVANAUGH,  J.,  concurring  in  judgment).
The EPA notes that the Corps had promulgated regulations 
adopting that interpretation before Congress amended the
CWA  in  1977  to  include  the  reference  to  “adjacent”  wet-
lands in §1344(g)(1).  See 42 Fed. Reg. 37144.  This term, 
the  EPA  contends,  was  “ ‘ “obviously  transplanted  from” ’ ” 
the Corps’ regulations and thus incorporates the same def-
inition.   Brief  for  Respondents  22 (quoting  Taggart  v.  Lo-
renzen, 587 U. S. ___, ___ (2019) (slip op., at 5)). 

This argument fails for at least three reasons.  First, as 
we  have  explained,  the  text  of  §§1362(7)  and  1344(g)(1)