Document ID: ./input/supremecourt_opinions/opinions/08pdf/07-588.pdf/07-588.pdf
Page Number: 12.0

Cite as:  556 U. S. ____ (2009) 

9 

Opinion of the Court 

requires the EPA to set “effluent limitations [which] shall 
require  the  elimination  of  discharges  of  all  pollutants  if
the Administrator finds . . . that such elimination is tech-
nologically  and  economically  achievable,”  §1311(b)(2)(A) 
(emphasis  added). 
  See  also  §1316(a)(1)  (mandating
“where  practicable,  a  standard  [for  new  point  sources]
permitting  no  discharge  of  pollutants”  (emphasis  added)). 
Section  1326(b)’s  use  of  the  less  ambitious  goal  of  “mini-
mizing adverse environmental impact” suggests, we think,
that  the  agency  retains  some  discretion  to  determine  the
extent  of  reduction  that  is  warranted  under  the  circum-
stances.  That  determination  could  plausibly  involve  a 
consideration  of  the  benefits  derived  from  reductions  and 
the costs of achieving them.  Cf. 40 CFR §125.83 (defining 
“minimize”  for  purposes  of  the  Phase  I  regulations  as 
“reduc[ing]  to  the  smallest  amount,  extent,  or  degree 
reasonably  possible”).  It  seems  to  us,  therefore,  that  the 
phrase  “best  technology  available,”  even  with  the  added
specification  “for  minimizing  adverse  environmental  im-
pact,”  does  not  unambiguously  preclude  cost-benefit 
analysis.5 

Respondents’ alternative (and, alas, also more complex) 
argument rests upon the structure of the Clean Water Act.
The  Act  provided  that  during  its  initial  implementation 
period existing “point sources”—discrete conveyances from
which  pollutants  are  or  may  be  discharged,  33  U. S. C. 
§1362(14)—were subject to “effluent limitations . . . which 
shall require the application of the best practicable control 
technology  currently  available.”    §1311(b)(1)(A)  (emphasis 

—————— 

5 Respondents  concede  that  the  term  “available”  is  ambiguous,  as  it 
could mean either technologically feasible or economically feasible.  But 
any ambiguity in the term “available” is largely irrelevant.  Regardless
of the criteria that render a technology “available,” the EPA would still
have to determine which available technology is the “best” one.  And as 
discussed  above,  that  determination  may  well  involve  consideration  of
the technology’s relative costs and benefits.