Document ID: EPA-HQ-OAR-2003-0049-0009
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-09-08T04:00Z

(
REF:
OZPMRH­
5­
97)

MEMORANDUM
SUBJECT:
Guidance
for
Implementing
the
1­
Hour
Ozone
and
Pre­
Existing
PM
10
NAAQS
FROM:
Richard
D.
Wilson,
Acting
Assistant
Administrator
for
Air
and
Radiation
(
6101)

TO:
Regional
Administrator,
Regions
I­
X
As
you
know,
on
July
18,
1997,
EPA
replaced
the
1­
hour
ozone
standard
with
an
8­
hour
standard
at
a
level
of
0.08
parts
per
million
(
ppm).
The
Agency
also
revised
the
primary
and
secondary
national
ambient
air
quality
standards
(
NAAQS)
for
particulate
matter
(
PM)
by
establishing
annual
and
24­
hour
PM
2.5
standards
and
by
changing
the
form
of
the
existing
24­
hour
PM
10
standard.
The
existing
annual
PM
10
standard
is
retained;
however,
for
the
revised
PM
NAAQS,
the
standard
conditions
of
temperature
and
pressure
adjustment
have
been
removed.
These
new
standards
became
effective
September
16,
1997.

Guidance
for
continuing
the
implementation
of
the
Clean
Air
Act
(
Act)
requirements
for
the
1­
hour
ozone
and
pre­
existing
PM
10
NAAQS
following
EPA's
promulgation
of
the
new
8­
hour
ozone
and
PM
NAAQS
is
attached.
This
guidance
is
intended
to
ensure
that
momentum
is
maintained
by
the
States
in
their
current
programs
while
moving
toward
developing
their
plans
for
implementing
the
new
NAAQS,
and
it
applies
to
all
areas
now
subject
to
the
1­
hour
ozone
standard
and
the
pre­
existing
PM
10
standard
regardless
of
attainment
status.
On
July
16,
1997,
President
Clinton
issued
a
directive
to
Administrator
Browner
on
implementation
of
the
new
standards
for
ozone
and
PM.
In
that
directive,
the
President
laid
out
a
plan
on
how
these
new
standards,
as
well
as
the
current
1­
hour
ozone
and
pre­
existing
PM
standards,
are
to
be
implemented.
The
attached
guidance
reflects
the
Presidential
Directive.

Although
the
8­
hour
ozone
standard
replaces
the
1­
hour
standard,
the
1­
hour
standard
will
continue
to
apply
to
an
area
for
an
interim
period
until
EPA
makes
a
determination
that
the
area
has
air
quality
meeting
the
1­
hour
standard.
As
a
consequence,
under
the
Act,
the
provisions
of
subpart
2
of
part
D
of
title
I,
which
govern
implementation
of
the
1­
hour
ozone
standard
in
nonattainment
areas,
will
continue
to
apply
in
those
areas
until
EPA
makes
a
determination
that
the
area
has
air
quality
meeting
the
1­
hour
standard.
Similarly,
the
provisions
of
subpart
4
of
part
D
of
title
I,
which
govern
implementation
of
the
pre­
existing
PM­
10
standards
in
nonattainment
areas,
will
continue
to
apply
for
an
interim
period
until
the
pre­
existing
PM
10
standard
is
revoked.
Guidance
on
how
EPA
will
revoke
the
applicability
of
the
1­
hour
ozone
and
pre­
existing
PM
10
standards
is
also
in
the
attachment.
2
The
EPA
interprets
the
Act
to
provide
that
the
detailed
provisions
of
subpart
2
of
part
D
of
title
I
are
clearly
and
explicitly
tied
to
the
ozone
NAAQS
in
existence
at
the
time
of
the
enactment
of
the
1990
Amendments
to
the
Act.
Moreover,
the
provisions
of
subpart
4
of
part
D
apply
only
to
PM
10
NAAQS
(
this
includes
pre­
existing
and
revised
PM
10
NAAQS).
Thus,
the
provisions
of
subparts
2
and
4
would
not
govern
the
implementation
of
the
8­
hour
ozone
and
PM
2.5
NAAQS.
Instead,
the
general
planning
requirements
of
part
A
of
title
I
and
the
nonattainment
planning
requirements
of
subpart
1
of
part
D
of
title
I
govern
the
implementation
of
the
new
8­
hour
ozone
standard
and
the
PM
2.5
standard.
The
EPA
will
prepare
guidance
and
proposed
regulations
on
implementing
these
new
standards
in
the
near
future.

The
purpose
of
this
guidance
is
to
set
forth
EPA's
current
views
on
the
issues
discussed
herein.
These
issues
will
be
addressed
in
future
rulemakings
as
appropriate,
e.
g.,
actions
approving
or
disapproving
State
implementation
plans
submittals.
In
those
rulemakings,
EPA
will
propose
to
take
a
particular
action
based
in
whole
or
in
part
on
its
views
of
the
relevant
issues,
and
the
public
will
have
an
opportunity
to
comment
on
EPA's
interpretations
during
the
rulemakings.
When
EPA
issues
final
rules
based
on
its
views,
those
views
will
be
binding
on
the
States,
the
public,
and
EPA
as
a
matter
of
law.

If
you
have
any
questions
during
implementation
of
this
guidance,
please
contact
John
Seitz,
Director
of
the
Office
of
Air
Quality
Planning
and
Standards.
The
staff
contacts
are
Sharon
Reinders
(
ozone)
at
919/
541­
5284
and
Robin
Dunkins
(
PM)
at
919/
541­
5335.

Attachment
cc:
Air
Division
Director,
Regions
I­
X
Air
Programs
Manager,
Regions
I­
X
William
Hunt,
EMAD
Margo
Oge,
OMS
Rich
Ossias,
OGC
Sally
Shaver,
AQSSD
John
Seitz,
OAQPS
Lydia
Wegman,
OAQPS
EPA:
OAR:
OAQPS:
AQSSD:
OPSG:
SREINDERS\
LTilley:
NCM
RM
510A:(
MD­
15)
1­
5526
File
Name:
I:\
SEC\
REINDERS\
IIG1223.
FIN
December
23,
1997
Coordinated
w/
the
all
Regions,
Gay
MacGregor
w/
OMS,
Rich
Ossias
of
OGC.
Please
note
that
Sally
Shaver
and
Lydia
Wegman
have
cleared
this.
1
Guidance
for
Implementating
the
1­
Hour
Ozone
and
Pre­
Existing
PM
10
NAAQS
PREFACE
The
purpose
of
this
guidance
is
to
set
forth
EPA's
current
views
on
the
issues
discussed
herein.
These
issues
will
be
addressed
in
future
rulemakings
as
appropriate,
e.
g.,
actions
approving
or
disapproving
State
implementation
plans
submittals.
In
those
rulemakings,
EPA
will
propose
to
take
a
particular
action
based
in
whole
or
in
part
on
its
views
of
the
relevant
issues,
and
the
public
will
have
an
opportunity
to
comment
on
EPA's
interpretations
during
the
rulemakings.
When
EPA
issues
final
rules
based
on
its
views,
those
views
will
be
binding
on
the
States,
the
public,
and
EPA
as
a
matter
of
law.

OZONE
GUIDANCE
The
following
guidance
presents
EPA's
view
on
key
issues
regarding
the
ongoing
programs
implemented
by
State,
local,
and
tribal
air
pollution
control
agencies
to
attain
the
1­
hour
ozone
national
ambient
air
quality
standards
(
NAAQS).
The
purpose
and
intent
are
to
ensure
that
the
momentum
gained
by
States,
local
governments,
and
tribes
to
attain
this
NAAQS
is
not
lost
when
moving
toward
implementation
and
attainment
of
the
new
8­
hour
NAAQS.
The
topics
covered
are:

1.
Continued
Applicability
of
the
1­
Hour
Ozone
NAAQS
2.
Revocation
of
the
1­
Hour
Ozone
NAAQS
While
Retaining
the
8­
Hour
Ozone
NAAQS
3.
Reclassifications
and
Attainment
Date
Extensions
4.
Rate
of
Progress
(
ROP)
Requirements
for
Serious
and
Above
Areas
5.
Substitution
of
Credits
for
ROP
Emission
Reductions
6.
Findings
of
"
Failure
to
Submit"
Certain
Planning
Elements
7.
Attainment
Demonstrations
for
the
1­
hour
Ozone
NAAQS
a.
State
Implementation
Plan
Requirements
for
Serious
and
Higher
Classified
Nonattainment
Areas
b.
States
with
Areas
that
are
Bumped
Up
from
Moderate
to
Serious
1.
Continued
Applicability
of
the
1­
Hour
Ozone
NAAQS
On
July
18,
1997
(
62
FR
38856),
EPA
promulgated
a
regulation
replacing
the
1­
hour
ozone
NAAQS
with
an
8­
hour
NAAQS
at
a
level
of
0.08
ppm
(
40
CFR
part
50).
On
that
date,
EPA
also
announced
that
the
1­
hour
standard
would
no
longer
apply
to
an
area
once
EPA
determines
that
the
area
has
air
quality
meeting
the
1­
hour
standard.

Subpart
2
of
part
D
of
title
I
of
the
Clean
Air
Act
(
Act)
addresses
the
implementation
program
for
areas
designated
since
1991
as
nonattainment
for
the
1­
hour
ozone
standard.
On
December
13,
1996,
in
the
proposed
interim
implementation
policy
(
61
FR
65764),
EPA
proposed
that
the
provisions
of
subpart
2
would
not
apply
directly
to
the
implementation
of
a
new
2
ozone
NAAQS,
but
would
continue
to
apply
during
the
interim
period
after
promulgation
of
a
new
NAAQS
to
the
extent
they
are
retained
under
a
no­
backsliding
principle
and
to
the
extent
they
are
needed
to
comply
with
the
general
provisions
of
subpart
1.
However,
in
light
of
the
comments
received
on
that
proposal,
EPA
reconsidered
and
now
has
determined
that
the
provisions
of
subpart
2
continue
to
apply
directly
as
a
matter
of
law
to
ozone
nonattainment
areas
for
the
purposes
of
achieving
that
standard.
Therefore,
in
the
July
18
rulemaking,
the
EPA
announced
that
the
provisions
of
subpart
2
continue
to
apply
to
an
area
as
a
matter
of
law
until
EPA
determines
that
the
area
has
air
quality
data
meeting
the
1­
hour
standard
and
revokes
the
standard.
The
EPA
will
not
revoke
the
1­
hour
standard
in
an
area
that
is
violating
that
standard.
The
revocation
process
is
discussed
below.

Subpart
2
addresses
the
requirements
for
different
classifications
of
nonattainment
areas
for
the
1­
hour
standard
(
i.
e.,
marginal,
moderate,
serious,
severe
and
extreme).
For
example,
these
requirements
include
such
items
as
mandatory
control
measures,
annual
rate
of
progress
requirements
for
emission
reductions,
attainment
demonstrations
and
attainment
dates,
and
offset
ratios
for
the
emissions
from
new
or
modified
stationary
sources.
The
requirements
in
subpart
2
have
contributed
significantly
to
improvements
in
air
quality
since
1990.
The
EPA
believes
that
retaining
the
provisions
of
subpart
2
until
areas
have
air
quality
meeting
the
1­
hour
standard
will
result
in
numerous
benefits.
Retention
will
provide
continuity
in
implementation
programs
to
reduce
ozone
and
protect
public
health
and
the
environment,
provide
greater
assurance
that
the
currently
existing
and
required
control
measures
will
continue
to
be
implemented,
and
position
nonattainment
areas
on
the
path
toward
eventual
attainment
of
the
new
8­
hour
NAAQS.
Consistent
with
these
goals,
EPA
intends
to
interpret
section
110(
l)
of
the
Act
to
require
that
a
State
may
not
remove,
relax,
or
delay
an
ozone
control
measure
or
control
measure
commitment
that
is
included
in
the
SIP
unless
the
State
has
demonstrated
that
such
removal,
relaxation,
or
delay
will
not
adversely
affect
the
ability
of
the
State
to
prepare
and
submit
a
SIP
that
satisfies
requirements
for
reasonable
further
progress
toward
any
NAAQS
or
attainment
and
maintenance
of
any
NAAQS,
including
the
revised
ozone
NAAQS
and
new
PM
2.5
NAAQS.
The
continued
applicability
of
the
1­
hour
ozone
standard
is
explained
in
the
final
regulation
promulgating
the
new
ozone
standard
at
62
FR
38873
(
July
18,
1997)
and
the
Presidential
Directive
issued
to
the
EPA
on
July
16,
1997
(
62
FR
38421).
In
certain
cases
where
air
quality
data
through
1997
show
nonattainment,
EPA
may
be
redesignating
areas
from
attainment
to
nonattainment
for
the
1­
hour
standard.
Where
this
occurs,
States
should
follow
implementation
guidance
on
the
applicable
subpart
requirements
issued
at
the
time
of
redesignation.

2.
Revocation
of
the
1­
Hour
Ozone
NAAQS
While
Retaining
the
8­
Hour
Ozone
NAAQS
The
EPA
will
publish
a
list
of
areas
where
the
1­
hour
standard
is
being
revoked.
That
determination
will
be
based
solely
on
air
quality
showing
attainment
of
that
NAAQS.
At
the
effective
date
of
the
determination,
the
1­
hour
NAAQS
will
no
longer
be
in
effect
for
these
areas
although
the
8­
hour
ozone
NAAQS
continues
in
effect.
Also,
at
the
effective
date
of
the
revocation,
the
existing
area
designations
for
such
areas
will
no
longer
be
applicable
since
the
purpose
of
the
provisions
of
subpart
2
will
have
been
achieved
and
those
provisions
will
no
longer
3
apply.
As
long
as
an
area
is
violating
the
1­
hour
standard,
the
provisions
of
subpart
2
and
the
1­
hour
standard
continue
to
apply.
In
the
future,
the
EPA
intends
to
review
areas
eligible
for
revocation
of
the
1­
hour
standard
on
an
annual
basis
and
take
appropriate
action.
The
implications
of
revoking
the
1­
hour
NAAQS
on
the
Ozone
Transport
Region
are
not
discussed
in
this
guidance.
The
EPA
will
issue
separate
guidance
on
these
relationships.

In
the
past,
States
with
air
quality
data
showing
attainment
have
submitted,
and
EPA
has
approved,
redesignation
requests
and
maintenance
plans
for
these
areas.
From
now
on,
because
the
1­
hour
standard
and
subpart
2
will
no
longer
apply
to
an
area
once
the
area
achieves
that
standard,
new
redesignation
requests
as
well
as
new
maintenance
plans
for
that
standard
will
no
longer
be
required.

The
EPA­
approved
maintenance
plans
remain
effective
for
areas
where
the
1­
hour
standard
is
revoked.
However,
EPA
believes
maintenance
plans
for
areas
that
have
been
redesignated
to
attainment
for
that
standard
may
be
revised
to
withdraw
certain
contingency
measure
provisions
that
have
not
been
triggered
or
implemented
prior
to
EPA's
determination
of
attainment
and
revocation
of
that
standard.
Where
the
contingency
measure
is
linked
to
the
1­
hour
standard
or
air
quality
ozone
concentrations,
this
measure
may
be
removed
from
the
maintenance
plan.
Where
the
contingency
measure
is
linked
to
a
non­
air
quality
element,
such
as
emission
increases
or
vehicle
miles
traveled,
this
measure
can
only
be
removed
if
a
demonstration
shows
that
its
removal
will
not
adversely
affect
the
ability
of
the
area
to
attain
the
8­
hour
standard.
Contingency
measure
provisions
linked
to
the
1­
hour
standard
are
designed
to
assure
that
the
States
will
promptly
correct
any
violation
of
the
1­
hour
standard
which
occurs
after
the
redesignation
of
the
area
as
an
attainment
area
for
that
standard.
After
the
1­
hour
standard
is
revoked
for
an
area,
the
EPA
believes
that
it
would
be
permissible
for
States
to
revise
their
plans
to
withdraw
contingency
measures
related
to
the
old
standard
and
air
quality
for
the
area.
Allowing
such
revisions
would
be
consistent
with
section
110(
l)
of
the
Act
since
it
would
not
interfere
with
any
applicable
requirement
concerning
attainment
and
reasonable
progress,
or
any
other
applicable
requirement
of
the
Act.
Since
such
contingency
measures
are
designed
to
address
future
violations
of
a
standard
which
would
no
longer
exist
as
to
that
area,
it
is
no
longer
necessary
to
retain
them.
Further,
EPA
believes
that
future
attainment
and
maintenance
planning
efforts
should
be
directed
toward
the
new
8­
hour
NAAQS.

With
respect,
however,
to
contingency
measures
that
were
triggered
and/
or
implemented
prior
to
EPA's
revocation
of
the
1­
hour
standard,
such
measures
were
shown
to
be
necessary
to
correct
violations
that
occurred
while
that
standard
was
in
existence
for
the
area.
Therefore,
the
measures
should
be
retained
unless
the
State
can
show
under
section
110(
l)
that
it
would
not
interfere
with
any
applicable
requirement
concerning
attainment
and
reasonable
progress,
or
any
other
applicable
requirement
of
the
Act.

The
conformity
provisions
of
section
176(
c)
of
the
Act
apply
to
nonattainment
and
maintenance
areas.
Because
EPA­
approved
maintenance
plans
remain
effective
for
areas
where
the
1­
hour
standard
is
revoked,
transportation
and
general
conformity
will
continue
to
apply
in
4
those
areas
with
EPA­
approved
maintenance
plans,
even
after
the
1­
hour
ozone
standard
is
revoked.
However,
transportation
and
general
conformity
will
no
longer
apply
in
those
areas
that
do
not
have
EPA­
approved
maintenance
plans
and
for
which
the
1­
hour
standard
is
revoked.
Since
these
areas
will
no
longer
be
designated
nonattainment,
and
nothing
in
the
ozone
NAAQS
rule
provides
a
basis
for
retaining
conformity
requirements
for
ozone,
conformity
will
no
longer
apply.

Nevertheless,
EPA
strongly
encourages
these
areas
to
continue
coordinating
their
transportation
planning
and
air
quality
planning
processes.
Air
quality
agencies
should
be
consulting
with
transportation
agencies
when
developing
the
SIP,
in
order
to
ensure
that
the
SIP
properly
anticipates
future
motor
vehicle
emissions
and
adopts
appropriate
emission
reduction
strategies.
Likewise,
as
plans
for
transportation
investments
are
subsequently
developed,
a
process
for
considering
the
long­
term
air
quality
impacts
of
proposed
transporation
investments
is
a
common­
sense
planning
step
that
promotes
the
efficient
use
of
state
and
local
resources.
Additionally,
reconciling
proposed
transportation
investments
with
the
SIP's
goals
and
strategies
ensures
that
the
standards
are
achieved
on
time
and
through
an
efficient
allocation
of
emission
reductions
among
sources.
Finally,
the
integration
of
air
quality
and
transportation
planning
emphasizes
strategies
that
improve
the
efficiency
of
the
transportation
system,
which
in
itself
offers
long­
term
environmental
benefits
such
as
reducing
greenhouse
gas
emissions.

The
EPA
recognizes
that
for
other
Federal
actions
normally
subject
to
general
conformity,
coordination
with
the
State
is
usually
initiated
by
the
Federal
agency
when
an
action
is
expected
to
occur.
It
is
difficult
for
the
State
to
coordinate
in
advance
with
each
of
the
many
Federal
agencies
that
could
potentially
take
an
action.
However,
EPA
does
encourage
states
to
contact
the
major
Federal
facilities/
activities
in
their
nonattainment
areas
to
ensure
that
potential
future
Federal
activities
are
considered
when
the
SIP
is
developed.

Retaining
the
provisions
contained
in
subpart
2
until
EPA
determines
that
an
area
has
air
quality
meeting
the
1­
hour
standard
helps
areas
to
transition
to
attainment
planning
for
the
new
NAAQS
and
to
avoid
backsliding
to
degraded
air
quality.
Although
the
provisions
of
subpart
2
will
no
longer
apply
to
an
area
when
EPA
determines
that
the
area
has
air
quality
meeting
the
1­
hour
standard,
at
which
time
the
1­
hour
standard
will
be
revoked,
EPA
does
not
believe
that
the
revocation
authorizes
States
to
suspend,
delay,
or
revoke
any
SIP
measures
adopted
in
response
to
provisions
of
subpart
2
unless
the
State
demonstrates
under
section
110(
1)
that
such
suspension,
delay,
or
revocation
will
not
adversely
affect
the
ability
of
the
State
to
make
reasonable
further
progress
or
attain
or
maintain
any
NAAQS.

Designations
for
areas
regarding
the
new
8­
hour
NAAQS
will
take
place
in
the
future.
Implementation
of
the
new
8­
hour
standard
will
be
governed
by
the
provisions
of
subpart
1
of
part
D
of
title
I
of
the
Act.
Designations,
implementation
guidance
and
regulations
for
the
new
8­
hour
NAAQS
are
not
addressed
in
this
memo.
The
EPA
plans
to
address
implementation
of
the
new
NAAQS
during
the
next
year.
5
3.
Reclassification
and
Attainment
Date
Extensions
Retention
of
subpart
2
subjects
States
with
areas
failing
to
attain
the
1­
hour
NAAQS
to
reclassification
to
a
higher
class
and
to
the
mandatory
requirements
of
the
higher
class.
With
respect
to
moderate
areas
that
did
not
attain
the
1­
hour
NAAQS
by
the
attainment
date
in
the
Act,
those
areas
are
subject
to:
(
1)
the
reclassification
requirements
in
section
181(
b)(
2)
of
the
Act,
which
state
that
areas
will
be
reclassified
(
bumped
up)
to
the
next
higher
classification
or
classification
associated
with
the
area's
design
value;
and
(
2)
all
the
requirements
of
the
classification
to
which
they
are
bumped
as
specified
in
section
182.
Section
181(
b)(
2)
provides
that
this
bump­
up
action
is
to
occur
unless
the
area
is
granted
an
extension
of
its
attainment
date
by
EPA
in
accordance
with
section
181.

The
EPA
recently
initiated
individual
rulemaking
actions
proposing
that
certain
moderate
nonattainment
areas
failed
to
attain
the
1­
hour
NAAQS
by
November
15,
1996
as
required
by
the
Act
(
62
FR
46233,
and
62
FR
46238),
in
addition
to
publishing
a
final
rulemaking
action
on
a
moderate
nonattainment
area
(
62
FR
60001).
The
reader
is
referred
to
these
notices
for
additional
information.
With
respect
to
extensions
for
attainment
dates,
EPA
will
continue
to
consider
granting
up
to
two
1­
year
extensions
as
specified
in
the
Act.

4.
Rate
of
Progress
(
ROP)
Requirements
for
Serious
and
Above
Ozone
Areas
In
numerous
earlier
guidance
documents,
the
EPA
has
interpreted
the
section
182(
c)(
2)
reasonable
further
progress
requirement
as
mandating
volatile
organic
compounds
(
VOC)
or
nitrogen
oxides
(
NOx)
reductions
of
3
percent
per
year,
averaged
over
a
3­
year
period,
for
serious
and
above
ozone
nonattainment
areas
that
were
designated
and
classified
under
the
1­
hour
0.12
ppm
ozone
NAAQS.
The
EPA
refers
to
these
reductions
as
the
rate­
of­
progress
(
ROP)
requirement.
After
promulgation
of
the
new
NAAQS,
the
continuation
of
the
ROP
requirement
is
grounded
in
both
the
retention
of
the
1­
hour
0.12
ppm
ozone
NAAQS
and
the
requirements
of
section
182(
c)(
2)(
B)
in
subpart
2.
The
ROP
requirements
continue
until
the
area
has
air
quality
meeting
the
1­
hour
standard.
Accordingly,
areas
with
ROP
plans
approved
by
EPA
should
continue
to
implement
the
ROP
requirements
of
their
plans,
and
areas
that
have
not
submitted
plans
remain
subject
to
the
requirement.

5.
Substitution
of
Credits
for
ROP
Emission
Reductions
The
EPA
previously
proposed
some
additional
flexibility
for
a
nonattainment
area
as
it
attempts
to
meet
its
annual
ROP
emission
reductions.
This
flexibility
expanded
the
geographic
size
of
the
area
from
which
States
could
obtain
emission
reductions
to
meet
their
annual
average
3
percent
per
year
ROP
requirement.
Specifically,
EPA
proposed
that
an
area
in
nonattainment
for
the
1­
hour
NAAQS
should
be
allowed
to
take
credit
for
emissions
reductions
obtained
from
sources
outside
the
designated
nonattainment
area
for
the
post­
1999
ROP
requirement
as
long
as
the
sources
are
no
farther
than
100
km
(
for
VOC
sources)
or
200
km
(
for
NOx
sources)
away
from
the
nonattainment
area.
The
proposal
restricted
credits
to
emission
reductions
from
1
For
purposes
of
this
notice,
the
core
part
of
the
OTAG
domain
consists
of
the
following
States:
Alabama,
Connecticut,
District
of
Columbia,
Delaware,
Georgia,
Illinois,
Indiana,
Kentucky,
Maine,
Massachusetts,
Maryland,
Michigan,
Missouri,
North
Carolina,
New
Hampshire,
New
Jersey,
New
York,
Ohio,
Pennsylvania,
Rhode
Island,
South
Carolina,
Tennessee,
Vermont,
Virginia,
Wisconsin,
and
West
Virginia.

6
measures
not
otherwise
mandated
by
the
Act.
Because
the
ROP
requirement
is
a
general
ROP
requirement
for
at
least
3
percent­
per­
year
and
not
a
requirement
for
specific
programs
or
measures
such
as
vehicle
inspection
and
maintenance,
this
flexibility
would
continue
to
provide
the
same
ROP
in
terms
of
reducing
emissions.
As
explained
in
the
proposed
policy,
EPA
believes
that
this
additional
flexibility
for
crediting
reductions
outside
nonattainment
areas
is
consistent
with
the
Act.

Under
this
approach,
the
geographic
area
for
substitution
of
VOC
emission
reductions
remains
at
100
km
from
the
nonattainment
area
and
the
geographic
area
for
substitution
of
NOx
reductions
remains
at
200
km
from
the
nonattainment
area
with
the
possibility
for
additional
expansion
of
the
NOx
substitution
area
as
follows.
Based
on
its
review
of
the
public
comments,
EPA
believes
that
it
should
expand
the
allowable
area
for
NOx
substitutions
up
to
the
entire
State
for
those
States
in
the
core
part
of
the
Ozone
Transport
Assessment
Group
(
OTAG)
domain1,
i.
e.,
the
fine
grid
area,
if
they
so
choose.
(
The
OTAG
modeling
results
provide
an
adequate
technical
justification
for
statewide
NOx
emission
substitutions
for
ROP.)
All
other
States
implementing
a
NOx
substitution
strategy
for
ROP
would
be
restricted
to
a
distance
of
200
km
from
the
nonattainment
area,
unless
a
substitution
for
a
greater
distance
is
accompanied
by
adequate
technical
justification.
There
are
some
cases
in
the
western
portions
of
the
United
States
where
100
km
for
VOC
substitution
or
200
km
for
NOx
substitution
from
the
nonattainment
areas
are
not
appropriate
for
ROP
credit.
In
those
cases,
States
should
obtain
approval
from
the
appropriate
Regional
Office
to
verify
credit
and
applicability
prior
to
implementing
such
a
substitution.

The
reductions
obtained
outside
the
nonattainment
area
are
subject
to
the
same
use
restrictions
as
if
they
were
obtained
inside
the
nonattainment
area.
For
example,
the
same
reduction
should
not
be
double
counted
for
ROP
credit
and
for
new
source
growth
offsets.
EPA
believes
that
emissions
from
the
source(
s)
outside
the
nonattainment
area
that
are
involved
in
the
substitution
must
be
included
in
the
baseline
ROP
emissions
and
target
ROP
reduction
calculation.
Emissions
from
source(
s)
outside
the
nonattainment
area
that
are
not
involved
in
the
substitution
would
not
have
to
be
inventoried
or
included
in
the
baseline
ROP
emissions
and
target
ROP
calculation.
Under
this
approach,
States
will
need
to
track
and
record
emission
reductions
and
certify
to
EPA
the
amount
of
emission
reductions
achieved
for
ROP.

Further,
whereas
the
initial
Agency
proposal
disallowed
ROP
credit
from
measures
mandated
by
the
Act
and
implemented
by
States
outside
of
their
nonattainment
areas
to
reduce
7
precursors
of
ozone,
EPA
now
believes
that
it
should
allow
ROP
credit
for
such
reductions
of
ozone
precursors.
That
is,
creditable
reductions
achieved
outside
a
nonattainment
area
should
include
those
occurring
from
measures
such
as
those
proposed
by
EPA
in
its
regional
NOx
State
implementation
plan
call
(
signed
by
the
Administrator
on
October
10,
1997)
for
States
to
reduce
interstate
pollution
transport,
even
though
these
reductions
are
not
specifically
required
by
the
Act.
Also
now
creditable
outside
the
nonattainment
area
are
those
reductions
mandated
by
the
Act.
Examples
are
credit
for
maximum
achievable
control
technology
standards
controlling
hazardous
air
pollutants
that
are
precursors
of
ozone
or
the
Act's
title
IV
NOx
emission
reduction
requirements.
(
These
are
merely
illustrative
examples
of
such
programs,
not
an
inclusive
list
of
all
such
programs.)
This
is
consistent
with
EPA's
previous
interpretations
of
section
182(
c)(
2)(
B)
and
related
provisions
regarding
the
creditability
of
reductions
inside
nonattainment
areas
toward
ROP.

The
EPA
is
clarifying
its
proposal
for
areas
having
approved
NOx
waivers
granted
under
section
182(
f).
EPA
believes
that
the
NOx
reductions
achieved
outside
the
nonattainment
area
with
waivers
may
be
substituted
for
VOC
reductions
within
the
nonattainment
area
if
accompanied
by
adequate
technical
justification
at
the
time
of
submittal.
In
general,
EPA
believes
that
substitutions
in
waiver
areas
may
be
allowed
only
if
EPA
determines
that
the
substitution
would
result
in
a
reduction
in
ozone
concentrations
in
the
nonattainment
area
with
waivers.
For
most
areas,
NOx
waivers
were
granted
because
the
areas
were
already
attaining
the
ozone
NAAQS
and
are
not
at
issue
for
ROP.
For
other
areas,
NOx
waivers
were
granted
based
on
modeling
showing
that
NOx
reductions
were
not
needed
to
attain
or
resulted
in
ozone
disbenefits.
Accordingly,
although
EPA
generally
intends
to
allow
the
substitution
policy
as
described
above
to
apply
in
nonattainment
areas
that
received
NOx
waivers,
EPA
does
not
believe
that
it
should
allow
NOx
reductions
from
within
such
areas
to
be
substituted
for
required
VOC
reductions
without
certain
technical
assurances
in
cases
where
the
waiver
was
granted
based
on
a
showing
that
NOx
reductions
resulted
in
ozone
disbenefits
or
otherwise
provided
no
benefits.
Thus,
in
order
for
substitutions
to
be
allowed
in
such
ozone
disbenefit
waiver
areas,
the
technical
justification
should
be
accompanied
by
an
adequate
showing
that
the
NOx
reductions
will
lead
to
lower
ozone
concentrations
in
the
nonattainment
area
and
should
also
be
accompanied
by
an
amended
NOx
waiver
request
with
modeling
data
supporting
the
revised
NOx
waiver.

The
EPA
believes
that
the
start
date
of
the
expanded
locality­
based
substitution
credit
for
ROP
is
changed
from
post­
1999
ROP
requirements
to
post­
1996
requirements.
EPA
does
not
believe
that
it
may
allow
credit
for
substitutions
to
complete
or
revise
the
15
percent
ROP
requirement
for
VOC
emission
reductions
in
nonattainment
areas
through
1996.
Although
the
start
date
for
application
of
ROP
substitution
reductions
from
outside
the
nonattainment
area
would
apply
to
post­
1996
ROP
requirements,
consistent
with
past
Agency
policy,
States
would
be
able
to
bank
excess
earlier
reduction
credits
(
NOx
or
VOC)
to
apply
to
post­
1996
and
later
requirements.

The
EPA
believes
the
Act
does
not
allow
States
to
substitute
other
controls
for
specifically
mandated
measures
such
as
inspection/
maintenance
or
reasonably
achievable
control
8
technology
that
are
required
by
the
Act
due
to
the
area
classification
or
location
within
the
Ozone
Transport
Region.
In
these
cases,
the
measures
are
prescribed,
required
controls
that
the
Act
does
not
allow
EPA
discretion
to
remove.

Substitutions
are
restricted
to
intrastate
areas
unless
two
or
more
States
involved
reach
mutual
agreement.
Similarly,
application
of
credits
from
substitutions
should
be
limited
to
only
one
nonattainment
area
unless
two
or
more
areas
involved
reach
agreement
on
dividing
the
credit
between
them,
such
that
the
same
emission
reductions
are
not
credited
toward
the
progress
requirements
for
more
than
one
area.
Interstate
substitutions,
like
intrastate
substitutions,
must
be
enforceable
by
the
States
in
which
the
affected
sources
are
located.

6.
Findings
of
"
Failure
to
Submit"
Certain
Planning
Elements
By
notice
published
July
10,
1996
(
61
FR
36292),
EPA
issued
three
types
of
findings
for
nine
nonattainment
areas
in
ten
States
and
the
District
of
Columbia
and
thereby
started
sanctions
clocks
for
these
areas.
These
findings
were
for
failure
to
submit:
(
1)
a
SIP
provision
requiring
emissions
reductions
of
9
percent
in
ozone
precursors
from
the
end
of
1996
to
1999,
(
2)
a
SIP
commitment
to
adopt
any
additional
regulations
needed
to
complete
the
requirements
for
ROP
reductions
after
1999
and
until
the
attainment
date,
and
(
3)
a
SIP
commitment
to
adopt
additional
measures
needed
for
attainment
of
the
1­
hour
0.12
ppm
NAAQS.
Note
that
areas
classified
as
serious
only
received
the
first
and
third
findings.

In
addition,
EPA
issued
two
types
of
findings
to
the
Commonwealth
of
Pennsylvania
for
the
Philadelphia
area
and,
thereby,
started
sanctions
clocks
for
that
area
(
62
FR
27201,
May
19,
1997).
These
findings
were
for
failure
to
submit:
(
1)
a
SIP
commitment
to
adopt
any
additional
regulations
needed
to
complete
the
requirements
for
ROP
reductions
after
1999
and
until
the
attainment
date,
and
(
2)
a
SIP
commitment
to
adopt
additional
measures
needed
for
attainment
of
the
1­
hour
0.12
ppm
NAAQS.

Because
the
provisions
of
subpart
2,
section
182(
c)(
2),
that
relate
to
ROP
plans
and
attainment
demonstrations
continue
to
apply
to
areas
not
attaining
the
1­
hour
ozone
standard,
all
findings
made
by
EPA
and
associated
sanctions
and
Federal
implementation
plan
clocks
continue
to
apply.
Also,
because
the
current
subpart
2
implementation
program
is
retained,
all
other
previously­
issued
findings
pertaining
to
required
elements
in
the
Act's
ozone
program
are
carried
forward.

7.
Attainment
Demonstrations
for
the
1­
Hour
Ozone
NAAQS
a.
State
Implementation
Plan
Requirements
for
Serious
and
Higher
Classified
Nonattainment
Areas
2
Exceptions
are
international
border
areas,
where
States
are
allowed
to
defer
the
adoption
of
plans
to
attain
and
maintain
the
1­
hour
NAAQS
due
to
emissions
emanating
from
outside
the
United
States
and
beyond
their
control.
The
EPA
has
previously
issued
guidance
for
these
areas,
and
this
guidance
remains
applicable.
The
General
Preamble
provided
SIP
guidance
for
international
border
areas
(
57
FR
13569,
April
16,
1992).

3
Note
that
EPA
addressed
ROP
and
attainment
plans
for
serious
classified
nonattainment
areas
in
the
Nichols
policy
statement
mentioned
above.
That
policy
states
that
remaining
regulations
needed
for
serious
classified
nonattainment
areas
to
attain
should
be
adopted
and
implemented
in
time
for
those
areas
to
meet
their
attainment
date
of
November
1999.

9
The
Act
requires
attainment
demonstrations
for
the
1­
hour
NAAQS.
2
In
an
earlier
policy
statement
issued
on
March
2,
1995
by
Mary
D.
Nichols,
titled
"
Ozone
Attainment
Demonstrations,"
the
EPA
provided
guidance
on
attainment
demonstrations
for
the
1­
hour
NAAQS
for
serious
and
higher
classified
nonattainment
areas.
That
policy
was
closely
tied
to
the
progress
of
the
OTAG,
which
was
a
group
of
States
assembled
to
assess
the
transport
of
ozone
across
the
eastern
portion
of
the
United
States.
The
policy
indicated
that
States
participating
in
the
OTAG
would
have
until
mid­
1997
to
submit
attainment
demonstrations
to
EPA.
The
additional
time
beyond
1994
was
necessary
to
provide
States
with
time
to:
(
1)
participate
in
the
OTAG
assessment
of
ozone
transport
and
its
impact,
(
2)
review
and
complete
the
assessment
of
transported
ozone
and
precursors,
and
(
3)
complete
local­
area
modeling
needed
to
support
attainment
demonstrations.

Because
the
conclusion
of
the
OTAG
assessment
was
delayed
for
approximately
9
months,
in
this
guidance,
EPA
now
believes
States
should
have
until
April
1998
to
submit
attainment
demonstrations.
On
or
before
that
date,
States
with
serious
and
higher
classified
nonattainment
areas
should
forward
to
the
appropriate
EPA
Regional
Office
their
attainment
demonstrations
for
the
1­
hour
standard,
modeling
analysis,
and
supporting
documentation.
In
addition,
the
submittal
should
contain
the
following
five
elements:

(
1)
Evidence
that
all
measures
and
regulations
required
for
the
nonattainment
area
by
subpart
2
of
title
I
of
the
Act
to
control
ozone
and
its
precursors
have
been
adopted
and
implemented
or
are
on
an
expeditious
schedule
to
be
adopted
and
implemented.

(
2)
A
list
of
measures
and
regulations
and/
or
a
strategy
including
technology
forcing
controls
needed
to
meet
ROP
requirements
and
attain
the
1­
hour
NAAQS.

(
3)
For
severe
and
higher
classified
nonattainment
areas,
a
SIP
commitment
to
submit
a
plan
on
or
before
the
end
of
2000
which
contains
(
a)
target
calculations
for
post­
1999
ROP
milestones
up
to
the
attainment
date3
(
unless
already
submitted
to
satisfy
EPA's
previous
findings
of
failure
to
submit)
and
(
b)
adopted
regulations
needed
to
achieve
the
post­
1999
ROP
requirements
up
to
the
attainment
date
and
to
attain
the
1­
hour
NAAQS.
(
Note
that
for
many
States,
EPA
has
proposed
in
its
regional
NOx
SIP
call
to
require
submittal
of
NOx
reduction
10
programs
by
the
earlier
date
of
September
1999
and
that
reductions
from
these
programs
can
contribute
to
achieving
ROP.)

(
4)
A
SIP
commitment
and
schedule
to
implement
the
control
programs
and
regulations
in
a
timely
manner
to
meet
ROP
and
achieve
attainment.

(
5)
Evidence
of
a
public
hearing
on
the
State
submittal.

The
modeling
analysis
now
due
in
April
1998
should
demonstrate
attainment
of
the
1­
hour
NAAQS
by
the
date
required
in
the
Act.
States
may
wish
to
conduct
additional
modeling
analyses
to
support
the
attainment
demonstration;
however,
EPA
is
not
requiring
any
additional
modeling
and
will
accept
as
sufficient
existing
modeling
analyses
performed
in
the
OTAG
assessment
and/
or
local
area
modeling
that
is
already
available.
States
that
are
covered
by
EPA's
proposed
NOx
SIP
call
can
submit
a
modeling
analysis
that
reflects
boundary
conditions
that
are
consistent
with
the
regional
reductions
required
in
EPA's
proposed
NOx
SIP
call.
In
the
event
the
final
SIP
call
changes
significantly
from
what
was
proposed,
States
will
be
permitted
to
adjust
their
attainment
demonstrations
to
reflect
the
effects
of
the
final
SIP
call.
All
States
should
document
the
boundary
conditions
assumed
in
the
analysis
and
quantify
the
percent
of
VOC
and
NOx
reductions
needed
to
attain
the
1­
hour
standard.

The
modeling
analysis
should
be
based
on
the
guidance
documents
issued
by
the
EPA
titled
"
Guideline
for
Regulatory
Application
of
the
Urban
Airshed
Model,"
July
1991,
and
"
Guidance
on
Urban
Airshed
Model
Reporting
Requirements
for
Attainment
Demonstrations,"
March
1994.
States
may
base
the
attainment
test
on
the
document
titled
"
Guidance
on
Use
of
Modeled
Results
to
Demonstrate
Attainment
of
the
Ozone
NAAQS"
issued
by
EPA
in
June
1996.
Taken
together,
these
documents
address
regulatory
model
application,
modeling
reporting
requirements,
and
the
use
of
corroborative
data
such
as
air
quality
monitored
trends
and
results
from
observational
models
and/
or
other
photochemical
grid
models
for
demonstrating
attainment.

b.
States
with
Areas
that
are
Bumped
Up
from
Moderate
to
Serious
In
accordance
with
the
Act,
areas
designated
as
moderate
ozone
nonattainment
were
required
to
submit
to
EPA
a
SIP
with
specific
annual
reductions
in
ozone
precursors
sufficient
to
attain
the
1­
hour
NAAQS
by
November
15,
1996.
As
discussed
previously,
failure
to
attain
by
the
Act's
required
date
subjects
the
moderate
area
to
reclassification
(
bump
up)
to
a
higher
classification
and
new
control
requirements.

Individual
area
bump
ups
will
be
addressed
by
EPA
in
separate
regulatory
actions.
While
subpart
2
contains
the
general
SIP
requirements
for
serious
areas,
the
details
of
the
plan
requirements
for
areas
bumped
up
from
moderate
to
serious
will
be
addressed
in
connection
with
individual
area
bump
ups.
Similarly,
SIP
requirements
for
redesignated
areas
will
be
addressed
11
within
the
redesignation
process
for
an
individual
area.

Several
moderate
areas
submitted
plans,
including
an
attainment
demonstration,
for
the
1­
hour
NAAQS
but
did
not
in
fact
attain
the
NAAQS
by
the
November
15,
1996
attainment
deadline
in
the
Act.
Where
States
submitted
attainment
demonstrations
for
areas
that
failed
to
attain
the
1­
hour
NAAQS
or
where
these
areas
are
bumped
up
to
serious
areas,
such
attainment
demonstrations
are
no
longer
relevant
because
their
actual
air
quality
data
reflect
nonattainment.
Thus,
these
areas
become
subject
to
bump
up
to
the
serious
classification
and
the
statutory
requirements
applicable
to
serious
areas.
Once
such
areas
are
bumped
up,
the
obligation
to
demonstrate
attainment
by
the
former
attainment
date
will
be
superseded
by
the
requirement
to
demonstrate
attainment
by
the
serious
area
attainment
deadline.
In
addition
to
the
serious
area
requirements,
all
of
the
statutory
requirements
for
the
moderate
classification
and
regulations
submitted
by
States
and
approved
by
EPA,
except
for
the
requirement
to
demonstrate
attainment
by
November
15,
1996
remain
in
effect.
4PM
NAAQS
refers
to
both
PM
10
and
PM
2.5
standards.

12
PM
GUIDANCE
The
following
guidance
presents
EPA's
view
on
key
issues
regarding
the
ongoing
programs
implemented
by
State,
local
and
tribal
air
pollution
control
agencies
to
attain
the
preexisting
PM
10
NAAQS.
It
is
intended
to
ensure
that
the
improvements
in
air
quality
achieved
to
date
are
not
lost
when
moving
toward
implementation
and
attainment
of
the
new
PM
NAAQS.
The
topics
covered
are:

1.
Retention
of
the
PM10
Standard
2.
Attainment
Determinations
3.
Areas
Not
Attaining
the
Pre­
Existing
PM10
NAAQS
4.
Areas
Attaining
the
Pre­
Existing
PM10
NAAQS
a.
Designated
Nonattainment
Areas
with
an
Approved
Part
D
SIP
in
Place
b.
Designated
Nonattainment
Areas
that
Do
Not
Have
an
Approved
Part
D
SIP
c.
Attainment
Areas
d.
Unclassifiable
Areas
1.
Retention
of
the
PM10
Standard
On
July
18,
1997
(
62
FR
38652),
the
Agency
revised
the
primary
and
secondary
NAAQS
for
PM
by
establishing
annual
and
24­
hour
PM
2.5
standards
and
by
changing
the
form
of
the
existing
24­
hour
PM
10
standard.
In
addition,
the
existing
annual
PM
10
standard
was
retained.
With
respect
to
the
newly­
revised
suite
of
PM
NAAQS4,
40
CFR
part
50,
section
50.3,
was
revised
to
remove
the
requirement
to
correct
the
temperature
and
pressure
of
measured
PM
concentrations
to
standard
reference
conditions.
The
revised
PM
NAAQS
and
their
associated
appendices
became
effective
on
September
16,
1997.
Since
it
will
take
a
number
of
years
for
States
to
identify
PM
problems
under
the
revised
standards
and
to
develop
effective
means
for
addressing
those
problems,
EPA
believes
it
is
necessary
for
all
areas,
including
those
that
may
have
already
attained
the
pre­
existing
PM
10
standards
to
maintain
their
current
PM
10
implementation
efforts
for
the
purpose
of
protecting
public
health
during
the
transition
to
implementing
the
revised
PM
standards.
To
provide
for
an
effective
transition
from
the
preexisting
PM
standards
to
the
revised
PM
standards
(
in
light
of
the
need
to
establish
PM
2.5
monitoring
networks,
designate
areas,
and
develop
control
strategies
for
PM
2.5),
in
40
CFR
part
50,
section
50.6,
the
Administrator
determined
that
the
existing
standards
and
associated
provisions
will
continue
to
apply
for
an
interim
period.
The
duration
of
the
interim
period
will
depend
on
when
the
area
in
question
has
attained
the
pre­
existing
PM
10
standards,
has
included
all
state
adopted
and
implemented
PM10
measures
in
an
EPA
approved
SIP,
and
has
received
EPA
approval
of
a
SIP
that
must
be
submitted
pursuant
to
section
110(
a)(
1)
which
will
generally
provide
for
implementation,
maintenance
and
enforcement
of
the
revised
PM
NAAQS.
For
those
areas
which
have
not
attained
the
pre­
existing
PM
10
NAAQS,
that
standard
will
remain
until
EPA
13
promulgates
a
rule
pursuant
to
section
172(
e)
of
the
Act
to
assure
that
no
backsliding
occurs
during
the
interim
period
(
for
further
information,
see
paragraph
3
below).

On
September
16,
1997,
the
revised
PM
NAAQS
became
effective,
triggering
the
requirement
for
the
collection
and
reporting
of
PM
10
data
at
local
temperature
and
pressure
conditions.
However,
consistent
with
guidance
issued
in
EPA's
memo
entitled
"
Collection
and
Reporting
of
PM
10
Data,"
signed
by
William
Hunt
on
September
15,
1997,
collection
and
reporting
of
data
for
the
revised
PM
10
NAAQS
at
local
ambient
conditions
will
not
be
required
until
January
1,
1998.
Beginning
January
1,
1998,
all
areas
will
be
required
to
collect
and
report
ambient
PM
10
concentrations
to
AIRS­
AQS
at
local
temperature
and
pressure
conditions.
However,
until
the
pre­
existing
PM
10
NAAQS
is
revoked
for
an
area,
monitoring
and
reporting
of
PM
10
air
quality
data
under
both
the
pre­
existing
PM
10
NAAQS
methodology
(
i.
e.,
corrected
to
standard
temperature
and
pressure)
and
the
revised
PM
10
methodology
(
i.
e.,
reported
at
local
temperature
and
pressure)
are
required.
In
order
to
accommodate
this
requirement,
EPA
is
adjusting
the
AIRS­
AQS
system
to
handle
these
dual
data
reporting
requirements.
The
EPA
realizes
the
short­
term
burden
this
may
place
on
the
States
but
is
committed
to
working
with
them
to
revoke
the
standards
as
expeditiously
as
possible.
Guidance
on
the
technical
details
of
this
process
is
in
preparation.

2.
Attainment
Determinations
Consistent
with
40
CFR
part
50,
Appendices
K
and
J,
for
the
pre­
existing
PM
10
NAAQS,
attainment
determinations
are
based
on
a
calendar
year
of
ambient
monitored
data
corrected
to
standard
temperature
and
pressure,
and
are
exceedance
based.
Under
these
regulations,
an
area
is
considered
to
be
in
attainment
if
it
meets
the
criteria
of
no
more
than
one
exceedance
per
calendar
year
of
the
pre­
existing
PM
10
NAAQS
averaged
over
3
consecutive
years.
Since
the
PM
NAAQS
were
revised
mid­
year
(
i.
e.,
as
of
September
16,
1997),
the
Agency
has
concluded
that
in
order
to
comply
with
the
requirement
of
a
full
calendar
year
of
data,
it
will
base
attainment
determinations
for
the
pre­
existing
PM
10
NAAQS
on
ambient
monitored
data
reported
to
the
AIRS
database
for
the
years
1994
­
1996.
Thus,
data
covering
these
years
will
be
used
to
identify
those
areas
that
are
attaining
the
pre­
existing
PM
10
NAAQS.
These
data
will
also
serve
to
identify
the
existing
PM
10
areas
that
are
not
attaining
the
pre­
existing
PM
10
NAAQS
and,
therefore,
are
subject
to
the
section
172(
e)
rulemaking
to
avoid
backsliding
in
the
maintenance
of
acceptable
ambient
air
quality.
More
details
on
this
rulemaking
are
provided
below.

Also,
consistent
with
the
natural
events
policy
issued
by
Mary
Nichols
on
May
30,
1996,
if
an
attainment
or
unclassifiable
area
has
data
showing
violations
of
the
PM
10
NAAQS
due
to
natural
events
and
is
complying
with
the
policy
by
having
in
place
or
developing
a
natural
events
action
plan
(
NEAP),
then
EPA
will
not
use
those
data
in
any
air
quality
analysis
to
determine
whether
that
area
is
attaining
or
not
attaining
the
pre­
existing
PM
10
NAAQS.
In
the
event
an
area
fails
to
comply
with
the
natural
events
policy
within
the
specified
time
frames,
then
the
area
will
be
subject
to
the
section
172(
e)
no
backsliding
rulemaking.
Additionally,
if
an
area
has
violations
of
the
PM
10
NAAQS
due
to
a
significant
contribution
of
nonanthropogenic
emissions
or
would
14
attain
but
for
the
influence
of
PM
10
emissions
from
another
country
and
has
an
approved
waiver
pursuant
to
section
188(
f)
or
179(
B),
respectively,
of
the
Clean
Air
Act,
then
EPA
will
continue
application
of
the
waivers,
provided
the
data
continue
to
support
the
initial
finding
that
was
the
basis
for
approving
the
waiver.
Attainment
provisions
for
the
revised
PM
10
NAAQS
are
covered
in
40
CFR
part
50,
Appendices
M
and
N,
and
are
based
on
a
99th
percentile
form
of
the
standard;
however,
they
will
not
be
used
for
attainment
determinations
of
the
pre­
existing
PM
10
NAAQS.

3.
Areas
Not
Attaining
the
Pre­
Existing
PM10
NAAQS
For
those
areas
that
are
not
attaining
the
pre­
existing
PM
10
standards
as
of
September
16,
1997,
the
pre­
existing
standards
will
continue
to
apply
until
EPA
has
completed
its
rulemaking
under
section
172(
e)
of
the
Act
to
assure
that
no
backsliding
occurs
in
the
interim
period
(
62
FR
38701
and
62
FR
38429).
Section
172(
e)
provides
that,
if
the
Administrator
relaxes
a
national
ambient
air
quality
standard,
she
shall,
within
12
months
after
the
relaxation,
promulgate
requirements
applicable
to
all
areas
that
have
not
attained
that
standard
as
of
the
date
of
the
relaxation.
Those
requirements
shall
provide
for
controls
that
are
not
less
stringent
than
the
controls
applicable
to
areas
designated
nonattainment
before
such
relaxation.
The
suite
of
revised
PM
standards,
when
viewed
as
a
whole,
is
more
stringent
than
the
set
of
pre­
existing
PM
standards;
however,
the
shift
from
the
pre­
existing
PM
10
standards
to
the
revised
PM
10
standards,
when
viewed
by
itself,
represents
a
relaxation
of
the
existing
PM
10
standard.
As
a
result,
section
172(
e)
requires
EPA
to
issue
a
rule
within
12
months
to
apply
implementation
requirements
no
less
stringent
than
the
currently­
applicable
requirements
for
those
areas
that
had
not
attained
the
existing
PM
10
standards
by
September
16,
1997.
Pursuant
to
the
Presidential
Directive,
EPA
plans
to
propose
the
section
172(
e)
rule
for
notice
and
comment
in
the
near
future
and,
therefore,
is
deferring
a
detailed
discussion
of
the
implementation
requirements
for
subject
areas
until
that
time.

4.
Areas
Attaining
the
Pre­
Existing
PM10
NAAQS
For
the
areas
that
are
attaining
the
pre­
existing
PM
10
standards
at
the
time
of
the
effective
date
of
the
revised
PM
standards,
i.
e.,
September
16,
1997,
the
pre­
existing
PM
10
standards
will
continue
to
apply
until
the
areas
have
received
EPA
approval
of
a
SIP
that
includes
all
control
measures
which
were
adopted
and
implemented
at
the
State
level
to
meet
the
pre­
existing
PM
10
NAAQS.
As
indicated
in
the
Ozone
Section
with
regard
to
contingency
measures,
EPA
believes
that
where
the
contingency
measure
is
linked
to
the
pre­
existing
PM
10
standard
or
air
quality
PM
10
concentrations,
this
measure
may
be
removed
from
the
maintenance
plan.
Where
the
contingency
measure
is
linked
to
a
non­
air
quality
element,
such
as
emission
increases
or
vehicle
miles
traveled,
this
measure
can
only
be
removed
if
a
demonstration
shows
that
its
removal
will
not
adversely
affect
the
ability
of
the
area
to
attain
the
revised
PM
10
standard
or
the
PM
2.5
standard.
Contingency
measure
provisions
linked
to
the
pre­
existing
PM
10
standard
are
designed
to
assure
that
the
States
will
promptly
correct
any
violation
of
the
pre­
existing
PM
10
standard
which
occurs
after
the
redesignation
of
the
area
as
an
attainment
area
for
that
standard.
After
the
pre­
existing
PM
10
standard
is
revoked
for
an
area,
EPA
believes
that
it
would
be
permissible
for
States
to
15
revise
their
plans
to
withdraw
contingency
measures
related
to
the
old
standard
and
air
quality
for
the
area.
Allowing
such
revisions
would
be
consistent
with
section
ll0(
l)
of
the
Act
since
it
would
not
interfere
with
any
applicable
requirement
concerning
attainment
and
reasonable
progress,
or
any
other
applicable
requirement
of
the
Act.
Since
such
contingency
measures
are
designed
to
address
future
violations
of
a
standard
which
would
no
longer
exist
as
to
that
area,
it
is
no
longer
necessary
to
retain
them.
In
addition,
the
NAAQS
rule
provides
that
before
EPA
revokes
the
preexisting
PM
10
standard,
these
areas
must
receive
EPA
approval
of
a
SIP
under
section
110(
a)(
1)
that
addresses
the
revised
PM
NAAQS.

The
Act
requires
all
States
to
submit
SIPs
under
section
110(
a)(
1)
within
3
years
of
the
promulgation
of
any
NAAQS.
The
section
110
SIP
must
generally
provide
for
"
implementation,
maintenance,
and
enforcement"
of
the
NAAQS.
These
SIPs,
once
approved,
establish
the
general
authority
that
is
needed
for
implementation
of
any
NAAQS
and
constitute
the
infrastructure
of
the
air
quality
management
program
which
has
been
in
place
since
the
Act
was
enacted
in
1970.
As
previously
discussed,
the
pre­
existing
PM
10
NAAQS
will
remain
in
place
until
States
with
areas
that
are
attaining
that
NAAQS
have
submitted
and
EPA
has
approved
a
section
110
SIP
that
addresses
the
revised
PM
NAAQS.
Therefore,
each
State
will
need
to
review
and
revise,
as
appropriate,
its
section
110
SIP
for
this
purpose.
For
example,
an
adequate
section
110
SIP
should
enable
the
State
to
develop
a
PM
infrastructure
by
identifying
and/
or
establishing:
1)
the
authority
and
adequate
resources
to
develop
an
accurate,
complete,
and
comprehensive
inventory;
2)
the
authority
and
resources
to
develop,
deploy,
and
operate
the
PM
monitoring
network;
and
3)
the
authority
and
resources
to
perform
modeling.
It
should
be
noted
that
EPA
believes
that
many
of
the
existing
section
110
SIPs
for
currently­
attaining
PM
10
areas
may
be
adequate
to
meet
many
of
the
new
section
110
SIP
elements.
The
EPA
is
currently
in
the
process
of
developing
guidance
which
will
more
fully
address
the
necessary
requirements
for
an
adequate
section
110
SIP.
This
guidance
will
be
completed
in
the
near
future.

Consistent
with
the
Presidential
Directive,
States
will
have
up
to
3
years
(
July
2000)
to
submit
their
section
110
SIP
for
the
revised
PM
NAAQS
for
EPA
approval.
States
are
encouraged
to
submit
these
SIPs
early
in
order
to
have
the
pre­
existing
PM
10
NAAQS
revoked
as
expeditiously
as
possible.
Since
the
goal
of
retaining
the
pre­
existing
PM
10
NAAQS
while
transitioning
from
an
existing
to
revised
NAAQS
is
to
first,
preserve
control
measures
implemented
to
date,
and
second,
to
ensure
that
States
have
the
authority
and
ability
to
implement
the
revised
PM
NAAQS,
EPA
believes
that,
while
section
110
could
conceivably
encompass
a
broad
range
of
requirements,
including
ones
that
are
primarily
procedural
and
administrative
in
nature,
there
are
certain
fundamental
requirements
that
will
be
key
to
the
States'
ability
to
demonstrate
that
the
section
110
SIP
is
adequate
to
implement
the
revised
PM
10
and
PM
2.5
standards.
Thus,
EPA
will,
on
a
case­
by­
case
basis,
consider
and
fully
approve
those
section
110
SIPs
that
adequately
demonstrate
that
these
key
requirements
have
been
met,
that
is,
that
the
areas
in
question
have
adopted
all
state­
implemented
measures
in
the
SIP,
and
have
identified
and/
or
established
the
authority
and
ability
to
develop
the
infrastructure
needed
to
implement
the
revised
suite
of
PM
standards.
In
those
instances
where
a
State
believes
its
current
section
110
SIP
is
adequate
to
provide
the
authority
to
implement
any
PM
NAAQS,
the
Governor,
or
his/
her
16
designee,
should
submit
a
letter
certifying
that
the
existing
section
110
SIP
is
adequate
to
implement
the
revised
PM
NAAQS.
The
EPA
will
then
initiate
rulemaking
on
the
adequacy
of
the
SIP
for
the
purpose
of
satisfying
the
necessary
requirements
of
section
110.

Once
EPA
approves
(
1)
a
SIP
that
has
all
State­
adopted
and
implemented
measures
and
(
2)
the
section
110
SIP,
EPA
will
take
action
to
revoke
the
pre­
existing
PM
10
NAAQS
for
that
area.
When
EPA
revokes
the
pre­
existing
24­
hour
PM
10
NAAQS
in
a
particular
area,
the
section
107
designation
for
PM
10
for
that
area
will
also
be
revoked.
However,
the
revocation
of
the
area
designations
for
PM
10
will
not
affect
the
applicability
of
the
PSD
program,
including
the
PM
10
increment,
which
will
continue
to
apply
to
an
area
even
after
the
revocation
of
the
existing
PM
10
designation
occurs.
EPA
will
provide
guidance
on
the
applicability
of
conformity
requirements
before
any
revocation
of
the
pre­
existing
PM
10
NAAQS.

a.
Designated
Nonattainment
Areas
with
an
Approved
Part
D
SIP
in
Place
For
those
areas
designated
nonattainment
that
attained
the
pre­
existing
PM
10
NAAQS
as
of
September
16,
1997
and
that
have
already
received
EPA
approval
of
their
part
D
SIP
embodying
all
of
the
measures
that
were
adopted
and
implemented
at
the
State
level,
no
further
submission
or
approval
pursuant
to
part
D
is
necessary.
As
described
above,
these
areas
will
still
need
to
satisfy
the
40
CFR
part
50,
section
50.6,
requirement
to
have
a
section
110
SIP
to
implement
the
revised
PM
NAAQS
approved
before
EPA
will
revoke
the
pre­
existing
PM
10
NAAQS.

b.
Designated
Nonattainment
Areas
That
Do
Not
Have
an
Approved
Part
D
SIP
For
those
designated
nonattainment
areas
that
attained
as
of
September
16,
1997
and
do
not
have
an
approved
part
D
SIP
in
place,
all
measures
that
were
adopted
and
implemented
at
the
State
level
for
the
purpose
of
meeting
the
pre­
existing
PM
10
standards
must
be
submitted
and
approved
by
EPA.
If
an
area
has
already
submitted
a
part
D
SIP
embodying
all
such
measures
to
EPA,
then
EPA
will
take
action
to
approve
those
measures
and
incorporate
them
into
the
SIP
for
the
State.
In
parallel
with
this
action,
the
Governor,
or
his/
her
designee
should
submit
to
EPA,
a
letter
certifying
that
the
measures
submitted
as
part
of
the
part
D
SIP
include
all
State­
level
adopted
and
implemented
measures
which
resulted
in
attainment
of
the
pre­
existing
PM
10
NAAQS.

If
an
area
has
not
yet
submitted
all
State­
level
adopted
and
implemented
measures
for
inclusion
in
the
SIP,
then
the
area
needs
to
submit
such
measures
for
EPA
approval
for
inclusion
in
the
SIP.
In
parallel
with
this
action,
the
Governor,
or
his/
her
designee
should
submit
to
EPA,
a
letter
certifying
that
the
measures
submitted
as
part
of
the
part
D
SIP
include
all
State­
level
adopted
and
implemented
measures
which
resulted
in
attainment
of
the
pre­
existing
PM
10
NAAQS.
As
stated
previously,
although
the
revocation
of
the
existing
PM
NAAQS
is
inherent
in
the
concept
of
establishing
a
revised
PM
NAAQS,
EPA
has
decided,
for
the
purposes
of
ensuring
that
air
quality
protection
is
not
diminished
on
the
way
to
meeting
the
revised
PM
10
and
PM
2.5
17
NAAQS,
to
continue
the
applicability
of
the
pre­
existing
PM
10
NAAQS
for
an
interim
period.
Inclusion
of
these
measures
in
the
SIP
will
assure
that
air
quality
gains
made
by
the
State
are
preserved.
However,
given
the
narrow,
targeted
purpose
underlying
retention
of
the
pre­
existing
PM
10
standards
and
the
limited,
temporary
period
during
which
those
standards
will
continue
to
apply,
EPA
does
not
believe
it
is
appropriate,
either
as
a
practical
or
regulatory
matter,
to
insist
on
the
submission
of
measures
beyond
those
already
developed
and
being
implemented
pursuant
to
part
D
at
the
State
level
to
address
the
PM
problem.
As
described
above,
these
areas
will
still
need
to
satisfy
the
40
CFR
part
50,
section
50.6,
requirement
to
have
a
section
110
SIP
to
implement
the
revised
PM
NAAQS
approved
before
EPA
will
revoke
the
pre­
existing
PM
10
NAAQS.

c.
Attainment
Areas
For
those
areas
that
were
redesignated
to
attainment
pursuant
to
section
107(
d)(
3)(
E)
of
the
Act
and
have
approved
maintenance
plans
embodying
all
of
the
measures
that
were
adopted
and
implemented
at
the
State
level,
no
further
submission
or
approval
pursuant
to
part
D
is
necessary.
As
described
above,
these
areas
will
still
need
to
satisfy
the
40
CFR
part
50,
section
50.6,
requirement
to
have
a
section
110
SIP
to
implement
the
revised
PM
NAAQS
approved
before
EPA
will
revoke
the
pre­
existing
PM
10
NAAQS.

d.
Unclassifiable
Areas
The
PM
NAAQS
rule
provides
that,
for
areas
that
are
currently
designated
as
unclassifiable,
all
control
measures
that
were
adopted
and
implemented
at
the
State
level
for
the
purposes
of
meeting
the
pre­
existing
PM
10
NAAQS
must
be
submitted
and
approved
by
EPA
for
inclusion
in
the
SIP.
In
parallel
with
this
action,
the
Governor,
or
his/
her
designee,
should
submit
a
letter
certifying
that
all
measures
submitted
reflect
any
and
all
controls
that
were
adopted
and
implemented
to
meet
the
pre­
existing
PM
10
NAAQS.
As
described
above,
these
areas
will
still
need
to
satisfy
the
40
CFR
part
50,
section
50.6,
requirement
to
have
a
section
110
SIP
to
implement
the
revised
PM
NAAQS
approved
before
EPA
will
revoke
the
pre­
existing
PM
10
NAAQS.