Document ID: ./input/supremecourt_opinions/opinions/19pdf/17-1498_8mjp.pdf
Page Number: 21.0

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

17 

Opinion of the Court 

“storage,  confinement,  perimeter  protection  using  dikes,
trenches, or ditches, clay cover, neutralization, cleanup of 
released  hazardous  substances  and  associated  contami-
nated  materials,”  and  so  forth.    42  U. S. C.  §9601(24).
While broad, the Act’s definition of remedial action does not 
reach so far as to cover planting a garden, installing a lawn 
sprinkler,  or  digging  a  sandbox.  In  addition,  §122(e)(6) 
applies  only  to  sites  on  the  Superfund  list.  The  Act  re-
quires  EPA  to  annually  review  and  reissue  that  list.
§9605(a)(8)(B).  EPA delists Superfund sites once responsi-
ble parties have taken all appropriate remedial action and 
the pollutant no longer poses a significant threat to public 
health or the environment.  See 40 CFR §300.425(e). 

The  landowners  and  JUSTICE  GORSUCH  alternatively 
argue that the landowners are not potentially responsible 
parties because they did not receive the notice of settlement
negotiations required by §122(e)(1).  Under a policy dating 
back to 1991, EPA does not seek to recover costs from resi-
dential landowners who are not responsible for contamina-
tion and do not interfere with the agency’s remedy.  EPA, 
Policy  Towards  Owners  of  Residential  Property  at  Super-
fund  Sites,  OSWER  Directive  #9834.6  (July  3,  1991),
https://www.epa.gov/sites/production/files/documents/policy-
owner-rpt.pdf.  EPA views this policy as an exercise of its 
“enforcement discretion in pursuing potentially responsible 
parties.”  Id., at 3.  Because EPA has a policy of not suing 
innocent homeowners for pollution they did not cause, it did 
not include the landowners in settlement negotiations.

But EPA’s nonenforcement policy does not alter the land-
owners’  status  as  potentially  responsible  parties.    Section 
107(a) unambiguously defines potentially responsible par-
ties and EPA does not have authority to alter that defini-
tion.  See,  e.g.,  Sturgeon  v.  Frost,  587  U. S.  ___,  ___,  n. 3 
(2019)  (slip  op.,  at  16,  n. 3).    Section  122(e)(1)  requires 
notification of settlement negotiations to all potentially re-
sponsible parties.  To say that provision determines who is