Document ID: ./input/supremecourt_opinions/opinions/19pdf/18-260_jifl.pdf
Page Number: 9

Cite as:  590 U. S. ____ (2020) 

5 

Opinion of the Court 

source and the navigable water,” then the permit require-
ment “does not apply.”  Id., at 54.  A pollutant is “from” a
point source only if a point source is the last “conveyance”
that conducted the pollutant to navigable waters.

The Solicitor General, as amicus curiae, supports Maui,
at least in respect to groundwater.  Reiterating the position
taken in a recent EPA “Interpretive Statement,” see 84 Fed. 
Reg. 16810 (2019), he argues that, given the Act’s structure 
and history, “a release of pollutants to groundwater is not 
subject  to”  the  Act’s  permitting  requirement  “even  if  the 
pollutants  subsequently  migrate  to  jurisdictional  surface
waters,” such as the ocean.  Brief for United States as Ami-
cus Curiae 12 (capitalization omitted).

We  agree  that  statutory  context  limits  the  reach  of  the
statutory phrase “from any point source” to a range of cir-
cumstances narrower than that which the Ninth Circuit’s 
interpretation  suggests.    At  the  same  time,  it  is  signifi-
cantly  broader  than  the  total  exclusion  of  all  discharges
through groundwater described by Maui and the Solicitor
General. 

III 
Virtually all water, polluted or not, eventually makes its
way to navigable water.  This is just as true for groundwa-
ter.  See generally 2 Van Nostrand’s Scientific Encyclopedia 
2600  (10th  ed.  2008)  (defining  “Hydrology”).  Given  the 
power  of  modern  science,  the  Ninth  Circuit’s  limitation, 
“fairly traceable,” may well allow EPA to assert permitting
authority over the release of pollutants that reach naviga-
ble waters many years after their release (say, from a well 
or pipe or compost heap) and in highly diluted forms.  See, 
e.g.,  Brief  for  Aquatic  Scientists  et al.  as  Amici  Curiae 
13–28. 

The  respondents  suggest  that  the  standard  can  be  nar-
rowed by adding a “proximate cause” requirement.  That is, 
to fall within the permitting provision, the discharge from