Document ID: EPA-HQ-OAR-2003-0053-2214
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2005-11-21T05:00Z

EPA
evaluated
the
interstate
ozone
contributions
in
terms
of
three
contribution
factors:
1)
the
magnitude
of
contribution;
2)
the
frequency
of
contribution;
and
3)
the
relative
amount
of
contribution.
For
each
factor,
EPA
calculated
metrics
to
quantify
the
contributions
to
ozone
nonattainment
The
relative
amount
of
the
contribution
is
used
to
compare
the
total
ozone
contributed
by
the
upwind
State
to
the
total
amount
of
nonattainment
ozone
in
the
downwind
area.
The
source
apportionment
metric
for
the
relative
amount
factor
is
the
total
average
contribution
to
exceedance
ozone
in
the
downwind
area
(
aka
average
percent
There
are
three
parts
to
the
calculation
of
the
average
percent
of
nonattainment
metric.
In
step
1,
the
ozone
values
for
each
of
the
exceedance
periods
in
a
particular
downwind
area
(
e.
g.,
Fulton
Co.)
are
summed
over
the
three
episodes
(
rounded
to
nearest
integer).
In
step
2,
the
total
ozone
from
the
previous
step
that
is
due
to
anthropogenic
sources
is
calculated
based
on
the
source
apportionment
results
(
rounded
to
neasrest
integer).
In
step
3,
the
contributions
from
a
given
source
region
to
this
downwind
area
are
summed
over
the
exceedance
periods
(
rounded
to
one
decimal
place).
The
total
contribution
calculated
in
step
3
is
then
divided
by
the
total
nonattainment
ozone
resulting
from
manmade
sources
in
step
2
to
determine
the
fraction
of
ozone
that
is
due
to
The
worksheet
entitled
Fulton
Co.
contains
the
results
of
this
calculation
&
each
of
its
pre­
final
steps.
The
value
from
Step
1
is
provided
in
cell
B2.
The
value
from
Step
2
is
provided
in
cell
B3.
The
values
for
Step
3
are
provided
for
each
upwind
State
in
column
B.
The
final
value
for
this
metric
is
shown
in
column
E
(
though
the
For
more
information
on
the
process
of
determining
interstate
ozone
contributions,
see
the
CAIR
air
quality
modeling
technical
support
document.
Please
direct
any
additional
questions
re:
these
data
to
Pat
Dolwick
at
Receptor
Area
=
Fulton
Total
ppb
=
120511
Anthro
ppb
=
96067
#
Values
=
1240
Source
Area
total
ppb
contributed
%
of
total
anthro
(
1
decimal)
%
of
total
anthro
(
rounded
to
nearest
integer)
GA
72983.7
76.0
76
TN
3829.6
4.0
4
AL
3790.0
3.9
4
KY
2431.3
2.5
3
SC
1917.6
2.0
2
NC
1435.9
1.5
2
TX
1138.4
1.2
1
IL
948.7
1.0
1
MO
913.7
1.0
1
AK
874.3
0.9
1
IN
858.7
0.9
1
FL
781.0
0.8
1
OH
710.5
0.7
1
OK
613.1
0.6
1
VI
524.7
0.5
1
WV
507.1
0.5
1
MS
467.7
0.5
1
PA
322.7
0.3
0
LA
243.7
0.3
0
KA
204.5
0.2
0
MD
111.6
0.1
0
IA
104.9
0.1
0
NY
90.5
0.1
0
NJ
47.1
0.0
0
MI
40.7
0.0
0
WI
39.0
0.0
0
CN
33.4
0.0
0
NE
20.0
0.0
0
MA
17.6
0.0
0
DE
16.5
0.0
0
CT
15.2
0.0
0
MN
9.2
0.0
0
GM
5.8
0.0
0
SD
5.7
0.0
0
RI
5.0
0.0
0
ME
3.2
0.0
0
NH
3.1
0.0
0
VT
1.7
0.0
0
AO
0.1
0.0
0
DC
0.0
0.0
0