1
draft
4/
9/
04
a
Comments
on
8­
Hour
Ozone
NAAQS
Implementation
Rule
(
Phase
I)

OMB
Comments
1.
COMMENT:
It
is
not
clear
that
Alternative
Y
is
superior
in
terms
of
the
Agency's
Preferred
Approach
(
Option
2).
For
example,
based
on
the
information
contained
in
the
"
Qualitative
Assessment",
10
areas
(
including
major
metropolitan
areas)
would
be
classified
lower
under
Alternative
Y
than
under
Option
2.
Only
8
areas
would
be
classified
lower
under
Option
2
than
under
Alternative
Y.
How
can
the
Agency
be
sure
that
Alternative
Y
is
superior
to
Option
2?

RESPONSE:
We
have
added
text
to
the
preamble
(
in
a
response
to
comment)
to
explain
why
Alternative
Y
is
not
preferred.
See
attachment
A.

2.
COMMENT:
How
much
discretion
does
EPA
have
over
the
control
requirements
in
the
higher
classifications
within
Subpart
2?
AND
Does
EPA
have
discretion
to
alter
the
Subpart
2
timeframes?

RESPONSE:
In
general,
we
do
not
believe
we
have
authority
to
waive
subpart
2
requirements
or
to
modify
the
statutorily
prescribed
time
frames.
We
plan
to
address
this
issue
in
the
phase
2
rulemaking,
where
we
will
address
the
remaining
implementation
issues
not
covered
in
the
phase
1
notice.
The
June
2,
2003
proposal
discussed
this
issue
and
noted
that
the
only
way
we
could
provide
an
exemption
from
the
control
requirements
under
subpart
2
was
if
application
of
the
requirement
would
produce
an
"
absurd
result"
and
that
we
would
consider
those
situations
on
a
case­
by­
case
basis.
(
See
68
FR
32825).
We
received
comments
on
this
issue,
which
we
will
address
in
the
phase
2
notice.

3.
COMMENT:
It
is
possible
that
two
areas,
each
with
the
same
8­
hour
design
value,
would
be
classified
differently;
one
in
Subpart
1,
and
the
other
in
Subpart
2.
Did
EPA
consider
altering
the
["
attainment"
I'm
assuming]
timeframe
under
Subpart
2
marginal
(
currently
3
years)
to
equate
with
the
Subpart
1
timeframe
(
5
years)?
(
The
other
timeframes
in
Subpart
2
would
have
to
be
changed
accordingly.)
If
such
a
change
is
made
in
the
final
rule,
are
there
"
logical
outgrowth"
problems?

RESPONSE:
Although
we
believe
we
have
a
good
argument
for
why
we
can
"
translate"
the
subpart
2
classification
table
to
8­
hour
values
based
on
the
Supreme
Court's
ruling,
our
attorneys
do
not
believe
we
can
defend
modifying
the
attainment
timeframes
in
the
table.
We
did
receive
a
number
of
comments
that
advocate
longer
attainment
times,
but
generally
in
the
context
of
placing
areas
in
other
classifications.
It
is
important
to
note
that
subpart
1
does
not
provide
areas
covered
by
that
subpart
with
5
years
to
attain.
Rather,
areas
must
demonstrate
attainment
as
expeditiously
as
practicable.
We
anticipate
that
most
subpart
1
areas,
like
most
areas
classified
as
marginal,
will
be
able
to
attain
in
3
years
after
designation.
2
4.
COMMENT:
What
is
the
definition
of
"
rural"
that
EPA
is
using
in
this
rule?

RESPONSE:
We
are
using
the
definition
that
parallels
the
provision
for
rural
transport
areas
in
section
182(
h)
of
the
Act,
namely
that
the
area
cannot
be
in
or
adjacent
to
a
C/
MSA.

5.
COMMENT:
On
pages
53­
54,
EPA
states
that
it
will
shortly
issue
new
guidance
on
determining
whether
a
region
is
subject
to
overwhelming
transport.
Please
provide
a
draft
of
this
guidance
to
OMB
for
review.

RESPONSE:
I
must
still
discuss
with
our
modeling
folks
before
providing
an
answer.
We
will
remove
the
"
shortly"
from
the
notice,
however.
In
general,
EPA's
modeling
guidance
receives
external
review
through
a
cross­
section
panel
of
modeling
experts.

6.
COMMENT:
EPA
is
limiting
the
"
overwhelming
transport"
areas
to
rural
areas.
The
explanation
given
on
pages
54­
55
of
the
preamble
is,
however,
not
very
convincing.
Recommend
that
EPA
allow
non­
rural
areas
to
be
considered
for
the
"
overwhelming
transport"
classification.

RESPONSE:
Part
of
the
unstated
rationale
for
restricting
the
overwhelming
transport
classification
to
rural
areas
is
the
fact
that
we
hope
to
make
a
similar
classification
available
in
the
PM2.5
implementation
program.
That
program
would
be
governed
entirely
under
subpart
1,
with
no
hierarchy
of
classifications
such
as
in
subpart
2.
Many
urban
areas
in
the
East
are
affected
by
transport
of
PM2.5
precursors.
To
have
a
large
number
urban
areas
eligible
for
an
overwhelming
transport
classification
does
not
appear
wise,
since
it
implies
that
they
cannot
do
much
to
solve
their
own
problem.
PM2.5
in
urban
areas
has
a
direct
component
that
EPA
expects
to
be
controlled
locally,
even
if
the
area
is
"
overwhelmed"
by
transport
of
secondary
PM2.5
components.
Therefore,
the
PM2.5
program
proposes
restricting
the
overwhelming
transport
classification
to
rural
areas.
We
are
attempting
to
structure
the
ozone
program
to
be
inconsistent
with
the
PM2.5
program
in
terms
of
how
to
handle
transport.

7.
COMMENT:
What
are
the
NSR
requirements
for
this
rule?

RESPONSE:
NSR
for
the
8­
hour
standard
will
be
addressed
in
the
second
phase
of
the
rule.

8.
COMMENT:
What
are
EPA's
plans
for
the
RIA?

RESPONSE:
Our
plans
for
additional
economic
analysis
(
not
an
RIA),
include
a
quantitative
cost
and
impact
assessment
in
support
of
the
portion
of
the
final
ozone
implementation
rule
addressing
rate
of
progress
and
reasonable
available
control
technology
decisions.
EPA
plans
to
use
2001­
2003
air
quality
data,
a
revised
2001
emissions
inventory
and
associated
projected
inventories
for
2007,
2010,
and
2015.
3
Emission
reduction
targets
will
be
developed
for
each
hypothetical
non­
attainment
area
and
the
costs
to
meet
these
targets
assessed.

The
geographic
scope
of
the
assessment
will
be
non­
attainment
areas
in
the
CAM­
X
domain
that
have
anticipated
differences
in
cost
and
impacts
due
to
alternatives
which
provide
plausible
bounds
regarding
rate
of
progress
and
reasonable
available
control
technology
determinations.

There
are
also
related
analyses
outside
the
scope
of
the
formal
rulemaking
that
will
look
at
cost/
feasibility
of
attaining
the
standard
in
non­
attainment
areas
in
the
CAM­
X
modeling
domain.
4
ATTACHMENT
A
(
ALTERNATIVE
Y
RESPONSE;
the
second
approach
in
the
text
below
refers
to
Alternative
Y
in
the
impact
analysis
addendum
document)

Under
one
of
these
options,
we
would
reduce
the
range
for
the
subpart
2
classifications,
which
would
have
classified
more
subpart
2
areas
in
higher
classifications,
thereby
extending
the
maximum
period
for
attainment.
We
have
addressed
the
problems
associated
with
that
kind
of
classification
structure
above.
Under
another
of
these
options,
the
classification
structure
would
have
relied
solely
on
8­
hour
ozone
design
values.
This
approach
was
a
variant
of
Option
2
in
which
all
areas
with
8­
hour
design
value
of
less
than
a
value
that
is
equivalent
to
the
1­
hour
value
of
0.121
ppm
would
be
covered
by
subpart
1.
This
option
has
the
opposite
effect
of
the
one
in
which
the
range
of
concentrations
is
reduced,
namely
that
more
areas
would
have
been
placed
in
lower
classifications,
increasing
the
number
of
areas
for
which
the
initial
classification
would
not
provide
sufficient
time
to
attain.
