Document ID: EPA-HQ-OAR-2003-0061-0411
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-09-15T04:00Z

1
Attachment
4
Nonattainment
Area
Designations
for
Chattanooga
under
the
PM2.5
Standard
This
document
contains
Georgia
EPD's
analysis
of
the
Georgia
counties
(
including
Walker
County
which
contains
a
violating
PM2.5
monitor)
which
are
part
of
or
adjacent
to
the
Chattanooga
urbanized
area.
EPD's
analysis
of
the
six
other
PM2.5
nonattainment
areas
(
Athens,
Atlanta,
Augusta,
Columbus,
Macon,
and
Floyd
County)
were
submitted
to
EPA
on
June
17,
2004.
The
analysis
for
the
Georgia
portion
of
the
Chattanooga
area
is
conducted
in
a
similar
manner
as
the
other
urbanized
areas
(
all
of
those
listed
above
except
Floyd
County.)

EMISSIONS
AND
AIR
QUALITY
ANALYSIS
The
first
step
in
revising
Georgia
EPA's
PM2.5
nonattainment
recommendations
for
Chattanooga
was
through
analysis
of
the
emissions
and
air
quality
in
the
potentially
included
areas.
EPA's
April
1,
2003,
memo
lists
emissions
and
air
quality
as
two
of
the
nine
factors
to
be
considered
in
assessing
which
areas
to
include
as
part
of
a
designated
nonattainment
area.
The
emissions
and
air
quality
analysis
was
done
through
the
use
of
a
revised
L­
Score
approach
that
is
described
in
detail
in
our
June
17,
2004
letter.
Georgia
EPD's
revised
L­
Score
analysis
for
Chattanooga
is
described
below.

Application
of
Updated
L­
Score
Equation
The
updated
L­
score
equation
(
Equation
2
of
6/
17/
04
letter)
was
used
to
evaluate
which
counties
in
the
Chattanooga
area
should
be
designated
nonattainment.
This
area
has
multiple
FRM
monitors
with
at
least
3
years
of
data
and
a
STN
monitor
with
speciated
PM2.5
data
available.
The
annual
average
background
concentration
and
the
speciated
percent
contributions
to
urban
excess
for
Chattanooga
were
calculated
by
EPA
using
measurements
at
the
Cohutta
IMPROVE
site.
Georgia
EPD
updated
emission
estimates
of
SO2,
NOx,
VOC,
and
NH3
with
the
recent
2002
CERR
inventory
for
the
counties
in
Georgia
that
are
currently
under
consideration
for
inclusion
in
the
Walker
County
nonattainment
area.
The
results
of
applying
Equation
2
to
Chattanooga
are
summarized
in
Table
A
(
attached).
This
table
includes
emissions,
L­
scores,
and
cumulative
L­
scores
for
each
county
under
consideration.
Counties
in
bold
text
are
part
of
the
1999
CMSA.

Chattanooga
Nonattainment
Area:
The
2003
design
value
for
Chattanooga
is
16.1
µ
g/
m3
and
the
urban
excess
is
5.2
µ
g/
m3.
According
to
Table
4­
A,
the
inclusion
of
Roane
(
TN),
Jackson
(
AL),
Floyd
(
GA),
Hamilton
(
TN),
and
McMinn
(
TN)
Counties
would
account
for
approximately
55%
of
the
emissions
responsible
for
the
area's
urban
excess.
Walker
County
(
GA)
has
also
been
added
because
it
is
a
county
where
a
violating
monitor
is
located.
Designating
these
six
counties
as
nonattainment
would
account
for
57%
of
the
urban
excess
(
3.0
µ
g/
m3)
in
Chattanooga.
Emission
reductions
resulting
in
a
37.1%
reduction
in
the
cumulative
Lscores
across
these
six
counties
should
be
enough
to
achieve
compliance
with
the
NAAQS.
According
to
this
analysis,
Catoosa
(
1.72%)
and
Dade
(
0.87%)
counties
contribute
a
combined
total
of
only
2.59%
to
the
total
urban
excess.
2
Table
4­
1:
Urban
Excess
values
for
Macon,
Augusta,
Columbus,
Athens,
Atlanta,
and
Chattanooga.
Macon
Augusta
Columbus
Athens
Atlanta
Chatt.
Urban
Monitor
(
U)
15.2
µ
g/
m3
15.2
µ
g/
m3
15.3
µ
g/
m3
15.6
µ
g/
m3
18.0
µ
g/
m3
16.1
µ
g/
m3
Regional
Monitor
(
R)
12.8
µ
g/
m3
11.7
µ
g/
m3
14.2
µ
g/
m3
14.1
µ
g/
m3
14.1
µ
g/
m3
 /
 
Background
Monitor
(
B)
11.0
µ
g/
m3
11.0
µ
g/
m3
11.0
µ
g/
m3
10.7
µ
g/
m3
10.7
µ
g/
m3
10.9
µ
g/
m3
Urban
Excess
(
U­
R)
2.4
µ
g/
m3
3.5
µ
g/
m3
2.5
µ
g/
m3
1.5
µ
g/
m3
3.9
µ
g/
m3
N/
A
Urban
Excess
(
U­
B)
4.2
µ
g/
m3
4.2
µ
g/
m3
4.3
µ
g/
m3
4.9
µ
g/
m3
7.3
µ
g/
m3
5.2
µ
g/
m3
%
Sulfate
Urban
Excess
22.03
%
38.21
%
27.66
%
22.84%
5.96
%
17.0%
%
Nitrate
Urban
Excess
4.28
%
9.81
%
2.03
%
36.90
%
0.00
%
7.0%
%
Carbon
Urban
Excess
36.35
%
31.23
%
58.20
%
15.18
%
86.70
%
66.0%
%
Crustal
Urban
Excess
27.33
%
2.50
%
0.98
%
21.32
%
7.34
%
10.0%
%
Amm.
Urban
Excess
10.00
%
18.25
%
11.13
%
3.77
%
0.00
%
N/
A
EPA's
Weighted
Emissions
Score
Analysis
On
June
29,
2004,
U.
S.
EPA
submitted
a
letter
to
Governor
Sonny
Perdue
notifying
him
of
EPA's
intent
to
modify
Georgia's
PM2.5
nonattainment
recommendations,
including
your
intentions
to
include
Dade
and
Catoosa
County
as
part
of
the
Chattanooga
PM2.5
nonattainment
area.
Included
with
that
letter
was
an
attachment
with
EPA's
justification
for
the
inclusion
of
Dade
and
Catoosa
County.
This
attachment
relies
heavily
on
EPA's
Weighted
Emissions
Score
(
WES)
analysis.
This
analysis
1)
starts
with
the
presumptive
boundaries
of
the
Chattanooga
MSA,
2)
selects
a
"
Cumulative
Weighted
Emissions
Score"
from
the
MSA
counties
that
results
in
a
certain
percentage
of
the
urban
excess
from
the
MSA
counties,
then
3)
adds
counties
that
are
outside
the
MSA
whose
WES
exceeds
that
of
the
MSA
county
with
the
lowest
WES
that
was
included
in
step
2.

EPA's
June
29th
letter
does
not
specify
which
Cumulative
WES
threshold
was
used
to
determine
which
counties
to
include
in
the
Chattanooga
PM2.5
nonattainment
area.
Hamilton,
Walker,
and
Marion
counties
account
for
81.5
percent
of
the
urban
excess
using
EPA's
methodology.
The
addition
of
Catoosa
county
brings
the
urban
excess
to
93.4%.
The
addition
of
Dade
County
(
the
remaining
county
in
the
Chattanooga
MSA)
brings
the
urban
excess
to
99.9%.
EPA's
May
5,
2004,
presentation
to
STAPPA/
ALAPCO
concerning
the
Weighted
Emissions
Score
analysis
states
on
slide
17
"
The
cumulative
weighted
emissions
score
can
be
used
to
identify
possible
guideline
levels
for
including
counties
in
the
CMSA
and/
or
for
including
adjacent
counties"
and
provides
example
levels
of
80%,
90%,
and
95%.
Catoosa
County
would
only
need
to
be
included
if
EPA
used
a
90%
level.
Dade
county
would
only
need
to
be
used
to
if
EPA
used
a
95%
level.

EPA's
WES
approach
and
apparent
arbitrary
WES
threshold
that
exceeds
95%
results
in
counties
within
the
Chattanooga
MSA
being
included
in
EPA's
recommended
nonattainment
whose
contribution
to
the
urban
excess
is
significantly
lower
than
counties
that
lie
just
outside
the
MSA.
Of
the
28
counties
included
in
EPA's
analysis
for
the
Chattanooga
PM2.5
nonattainment
area,
Dade
and
Catoosa
Counties
rank
23rd
and
18th,
respectively.
The
combined
WES
for
the
two
counties
with
violating
monitors
(
Hamilton
and
Walker)
plus
Jackson,
Roane
(
which
EPA
has
recommended
for
part
of
the
Knoxville
PM2.5
nonattainment
area)
and
Floyd
(
which
has
been
recommended
by
Georgia
EPD
as
a
separate
Floyd
County
PM2.5
nonattainment
area)
is
694.4.
The
combined
WES
for
Dade
and
Catoosa
Counties
is
only
18.4.

Both
EPD's
and
EPA's
analysis
clearly
show
that
neither
Dade
nor
Catoosa
County
should
be
included
as
part
of
the
Chattanooga
PM2.5
nonattainment
area.
3
Interstate
Emissions
Interstate
I­
75
travels
through
Catoosa
County.
EPD
has
calculated
the
PM2.5
direct
and
precursor
emissions
for
I­
75
and
compares
those
figures
with
total
mobile
source
emissions
and
total
emissions
from
Catoosa
County.

VOC
tpd
NOx
tpd
PM
tpd
SO2
tpd
NH3
tpd
I­
75
6.61
7.08
0.1446
0.2629
0.2057
total
mobile
10.53
10.51
0.22
0.40
0.32
%
of
total
41%
52%
47%
47%
47%

I­
75
is
a
major
north­
south
transportation
route;
therefore,
it
can
be
assumed
that
the
majority
of
interstate
traffic
in
Catoosa
county
is
through
traffic.
Since
emissions
from
these
vehicles
will
be
controlled
through
national
measures
and
not
state
measures,
designation
of
Catoosa
as
nonattainment
and
subsequent
local
control
measures
would
have
no
effect
on
these
emissions.

ANALYSIS
USING
OTHER
FACTORS
Despite
the
fact
that
both
EPA's
and
EPD's
emissions
and
air
quality
analsyis
indicates
that
neither
Dade
nor
Catoosa
County
should
be
included
in
the
Chattanooga
PM2.5
nonattainment
area,
EPD
has
examined
those
counties
using
the
seven
other
factors
as
described
in
U.
S.
EPA's
April
1,
2003,
memorandum
"
Designations
for
the
Fine
Particle
National
Ambient
Standards":

1.
population
density
and
degree
of
urbanization
2.
traffic
and
commuting
patterns
3.
expected
growth
4.
meteorology
5.
geography/
topography
6.
jurisdictional
boundaries
7.
level
of
control
of
emissions
Should
this
analysis
indicate
that
Dade
and/
or
Catoosa
Counties
could
significantly
contribute
to
PM2.5
levels
in
the
Chattanooga
Area
(
i.
e.,
factors
exceed
the
several
of
the
thresholds
described
below
by
significant
margins),
then
that
county
or
counties
may
need
to
be
considered
for
inclusion
in
the
nonattainment
area.

Page
6
of
the
April
1,
2003,
EPA
memorandum,
states
that
8­
hour
ozone
nonattainment
boundaries
should
be
considered
when
recommending
nonattainment
boundaries
for
PM2.5.
Catoosa
County
was
initially
included
in
the
Chattanooga
8­
hr
ozone
nonattainment
area.
However,
that
designation
has
been
stayed
due
to
EPA's
approval
of
the
Chattanooga
Early
Action
Compact.
Therefore,
the
Chattanooga
8­
hr
ozone
nonattainment
boundary
is
not
as
critical
in
determining
boundaries
for
PM2.5
nonattainment
as
it
is
for
currently
effective
8­
hr
ozone
nonattainment
areas.

The
following
thresholds
were
used
to
determine
whether
or
not
a
county
met
criteria
1,
2,
or
3.

A.
Population
Density
 
139
persons
per
square
mile
[
Derived
from
the
lowest
projected
2002
population
density
of
any
county
with
a
monitored
violation]
B.
Percent
Population
growth
­
20%
(
minimum
percent
urbanization
considered
by
the
U.
S.
4
Census)
and
2713
persons
[
Derived
from
lowest
increase
in
population
of
any
county
with
a
monitored
violation]
for
the
period
1990­
2000.
(
To
meet
this
criteria,
a
county
would
have
to
meet
or
exceed
both
the
percent
growth
and
numerical
growth
thresholds.
This
takes
into
account
the
fact
that
a
county
with
a
low
population
can
experience
a
high
percentage
growth
rate
with
only
a
small
increase
in
actual
population.)
C.
Percent
Urbanization
 
35%
(
minimum
percent
urbanization
considered
by
U.
S.
Census
Bureau)
for
2000
D.
In
Commutes
 
At
least
8913
vehicles
commuting
into
a
core
county
or
a
county
with
a
monitored
violation.
The
in­
commute
into
core
counties
or
counties
with
a
monitored
violation
was
only
considered
for
those
counties
outside
a
current
non­
attainment
area
[
Derived
from
15%
(
minimum
commute
considered
by
U.
S.
Census
Bureau
in
MSA
determinations)
multiplied
by
59,418
vehicles]
E.
Vehicle
Registration
 
59,418
vehicles
[
Derived
from
the
lowest
2003
vehicle
registration
of
any
county
currently
with
a
monitored
violation].
F.
Vehicular
Miles
Traveled
(
VMT)
in
county
 
1,557,806
miles
[
derived
from
lowest
2002
VMT
of
any
county
currently
with
a
monitored
violation]

The
specific
values
for
each
of
these
criteria
for
the
counties
analyzed
are
shown
below
and
are
compared
to
the
threshold
values.

Meteorology,
geography,
topography,
jurisdictional
boundaries,
and
level
of
control
of
emissions
are
considered
on
a
qualitative
basis
for
each
county.

EPA
has
recommended
Dade,
Catoosa,
and
Walker
County
as
part
of
the
Chattanooga
Macon
Nonattainment
Area.
Walker
county
contains
one
monitor
with
a
design
value
that
exceeds
the
annual
PM2.5
standard,
and
thus
is
automatically
included
in
EPD's
recommendation
for
inclusion.

Population
Density
 
County
Population
Density
persons/
square
mile
Catoosa
348
Dade
90
Threshold
139
Catoosa
County
meets
the
threshold
for
population
density.

Population
Growth
­

Population
Growth
County
percent
persons
Catoosa
25%
10,818
Dade
15%
2007
Threshold
20%
2713
Catoosa
County
meets
both
the
percent
and
total
persons
thresholds
for
population
density.
5
Percent
Urbanization
­

County
%
Urbanization
Catoosa
56%
Dade
4%
Threshold
35%

Catoosa
County
meets
the
threshold
for
percent
urbanization.

In
Commutes
­

In­
Commutes
County
to
Hamilton
Co.
to
Walker
Co.
Catoosa
12,320
1937
Dade
3091
747
Threshold
8913
8913
Catoosa
County
meets
the
threshold
for
commuting
to
Hamilton
County.
Neither
county
meet
the
threshold
for
commuting
to
Walker
County.

Vehicle
Registration
 
County
vehicle
registration
Catoosa
51,799
Dade
15,210
Threshold
59,418
Neither
County
meets
the
threshold
for
vehicle
registration.

Vehicle
Miles
Traveled
 
County
VMT
Catoosa
2,057,495
Dade
976,918
Threshold
1,557,806
Catoosa
County
meets
the
threshold
for
vehicle
miles
traveled.

Summary
of
Quantitative
Factors
 
Catoosa
County
meets
five
of
the
six
quantitative
criteria.
However,
except
for
population
density,
Catoosa
County
only
exceeds
each
of
the
criteria
by
a
small
margin.
Dade
County
meet
none
of
the
criteria.

Meteorology
 
Wind
frequency
data
was
obtained
from
U.
S.
EPA's
PM2.5
Designation
Technical
Information
web
page
(
www.
epa.
gov/
ttn/
naaqs/
pm/
pm25_
tech_
info.
html)
for
Hamilton
and
Walker
Counties
(
the
counties
where
the
violating
monitors
are
located).
Data
from
both
counties
show
a
strong
indication
of
prevailing
winds
from
the
north
by
northeast
and
6
south
by
southwest.
This
is
consistent
with
the
topography
of
the
region
(
discussed
further
below)
being
dominated
by
a
series
of
parallel
ridges
running
along
this
same
direction.
Because
of
the
predominating
wind
directions,
emissions
from
Catoosa
County
are
likely
to
have
an
impact
on
PM2.5
levels
in
Chattanooga.
However,
because
Lookout
Mountain
separates
Dade
County
from
the
remainder
of
the
Chattanooga
area,
emissions
from
Dade
County
are
less
likely
to
have
an
impact
on
PM2.5
levels
in
Chattanooga.

Geography
­
Both
Dade
and
Catoosa
Counties
are
adjacent
to
the
two
counties
(
Walker
and
Hamilton)
that
have
violating
monitors.
There
are
no
other
geographical
factors
effecting
these
counties.

Topography
 
The
topography
of
the
Chattanooga
area
is
dominated
by
a
series
of
parallel
ridges
running
generally
from
north
by
northeast
to
south
by
southeast.
The
primary
ridges,
running
from
east
to
west
are:
White
Mountain,
Peavine
Ridge,
Boynton
Ridge,
Missionary
Ridge,
Hawkins
Ridge,
and
Lookout
Mountain.
Most
of
these
ridges
peak
at
about
to
1000
to
1150
feet
in
elevation
from
base
of
around
700
feet,
with
the
tallest
being
1300
high
White
Oak
Mountain
to
the
east
and
the
significantly
taller
2100
foot
Lookout
Mountain
to
the
west.

The
Dade/
Walker
county
line
runs
atop
or
along
side
Lookout
Mountain
from
the
Tennessee
boarder
all
the
way
to
the
Alabama/
Georgia
boarder.
Therefore,
virtually
all
of
the
emissions
from
Dade
County
occur
west
of
Lookout
Mountain.
The
two
violating
PM2.5
monitors
in
the
Chattanooga
area
are
in
Rossville,
GA,
just
west
of
Missionary
Ridge,
and
in
East
Ridge,
TN,
between
Missionary
and
Boynton
Ridge,
both
east
of
Lookout
Mountain.
Based
on
EPD's
2002
emissions
inventory,
the
PM2.5
precursor
emissions
in
Dade
County
are
from
low­
emitting
area
and
mobile
sources.
There
are
no
major
stationary
sources
of
PM2.5
precursor
emissions
in
Dade
County.
Therefore,
PM2.5
precursor
emissions
from
Dade
County
are
less
likely
to
have
an
impact
on
the
Rossville
and
East
Ridge
PM2.5
monitors,
particularly
during
periods
of
atmospheric
inversion
which
are
more
likely
to
be
high
PM2.5
periods,
than
emissions
east
of
Lookout
Mountain
or
from
tall
stacks,
such
as
power
plants.

Jurisdictional
 
Catoosa,
Dade,
and
Walker
counties
are
part
of
the
Chattanooga
Metropolitan
Statistical
Area
(
MSA).
Most
of
Catoosa,
the
northeaster
portion
of
Walker
County,
and
a
very
small
portion
of
Dade
County
area
all
part
of
the
Chattanooga
MPO.
All
three
Georgia
counties
fall
within
the
jurisdiction
of
Georgia
EPD,
while
Hamilton
County
(
which
contains
the
urban
core
of
the
Chattanooga
area)
is
under
the
jurisdiction
of
a
local
air
pollution
control
agency,
the
Chattanooga­
Hamilton
County
Air
Pollution
Control
Bureau.
The
remaining
counties
that
EPA
has
recommended
for
inclusion
in
the
Chattanooga
PM2.5
nonattainment
county
fall
within
the
jurisdiction
of
the
Tennessee
Department
of
Environment
and
Conservation
(
Marion
County)
and
Alabama
Department
of
Environmental
Management
(
Jackson
County).

Dade
County
is
located
between
Hamilton
County
and
Jackson
County,
Alabama,
which
has
a
high
L­
Score.
U.
S.
EPA
has
suggested
to
EPD
that
Dade
County
would
need
to
be
included
in
the
Chattanooga
PM2.5
nonattainment
area
in
order
to
connect
Jackson
County,
which
contains
a
large
emitting
facility
(
i.
e.,
a
power
plant)
to
the
nonattainment
area.
However,
Marion
County,
Tennessee,
is
also
adjacent
to
both
Hamilton
and
Jackson
Counties.
Marion
County
has
a
higher
Cumulative
Weighted
Emissions
Score
as
calculated
by
U.
S.
EPA
and
revised
L­
Score
as
calculated
by
Georgia
EPD.
Therefore,
if
there
is
a
need
to
connect
Jackson
County
to
the
rest
of
the
Chattanooga
PM2.5
nonattainment
area,
it
is
more
logical
that
this
connection
be
through
Marion
County
and
not
Dade.
7
Level
of
Control
of
Emissions
 
None
of
the
Georgia
counties
recommended
by
U.
S.
EPA
as
part
of
the
Chattanooga
PM2.5
nonattainment
area
are
subject
to
air
quality
control
measures
more
stringent
than
elsewhere
in
the
state.
However,
both
Catoosa
and
Walker
Counties
have
committed
to
stage
I
vapor
controls
and
seasonal
open
burning
restrictions
as
part
of
the
Chattanooga
Early
Action
Plan
for
complying
with
the
8­
hr
ozone
standard.
These
rules
are
scheduled
to
be
adopted
by
the
Georgia
Board
of
Natural
Resources
in
December,
2004.
In
addition
to
these
two
regulatory
measures,
Catoosa
and
Walker
Counties
will
be
pursuing
local
control
measures
such
as
truck
stop
electrification
projects,
school
bus
conversions
and
retrofits,
and
voluntary
smog
alert
programs.

8­
hour
Ozone
Nonattainment
Boundaries
 
U.
S.
EPA
had
originally
designated
Catoosa
County
as
part
of
the
Chattanooga
8­
hour
ozone
nonattainment
area.
However
this
designation
was
deferred
until
September
30,
2005,
as
a
result
of
the
approval
of
the
Chattanooga
Early
Action
Compact.

PARTIAL
COUNTY
ANALYSIS
FOR
WALKER
COUNTY
Since
Walker
County
contains
a
violating
PM2.5
monitor
in
Rossville,
Walker
County
must
be
designated
as
non­
attainment
for
PM2.5.
However,
this
monitor
is
located
in
Rossville,
which
is
located
in
the
northeast
corner
of
the
county
near
the
Tennessee
boarder
and
Chattanooga.
Being
close
to
Chattanooga,
the
northern
portion
of
Walker
County
is
significantly
more
urbanized
than
the
southern
portion.
For
this
reason,
a
partial
county
designation
was
analyzed
for
Walker
County.

The
area
analyzed
for
partial
county
designation
included
that
portion
of
Walker
County
that
is
part
of
the
Chattanooga
MPO.
The
MPO
includes
the
areas
around
Rock
Springs
and
Chickamauga
and
northward,
excluding
the
top
and
eastern
slope
of
Lookout
Mountain,
but
including
the
city
of
Lookout
Mountain,
Georgia.
A
more
detailed
description
of
this
area
is
below.

Walker
county
has
a
total
area
of
447
square
miles.
Sixty
seven
percent
of
this
is
forested.
The
majority
of
the
forested
area
is
in
the
southern
and
western
part
of
the
county
outside
the
MPO.
The
forested
area
includes
a
portion
of
Chattahoochee
National
Forest
in
the
southeastern
part
of
the
county
and
Crawford­
Pigeon
Mountain
Wildlife
Management
Area
in
the
southwestern
part
of
the
county.
Three
of
the
four
incorporated
cities
in
Walker
County
are
within
the
MPO
(
MPO:
Chickamauga,
Lookout
Mountain,
Rossville;
non­
MPO:
LaFayette).

Walker
County
officials
have
submitted
data
on
the
portions
of
the
county
within
and
outside
of
the
Chattanooga
MPO.

Population
Density
 
County
Portion
Population
Density
persons/
square
mile
MPO
556
non­
MPO
78
Threshold
139
8
The
MPO
portion
of
the
county
exceeds
the
threshold
for
population
density
while
the
non­
MPO
portion
does
not.

Population
Growth
­

Population
Growth
County
Portion
percent
persons
MPO
9%
2515
non­
MPO
0.6%
198
Threshold
20%
2713
Neither
the
MPO
nor
non­
MPO
portion
of
Walker
County
exceeds
the
percent
population
growth
threshold.
The
total
persons
threshold
was
actually
based
on
Walker
County.
It
is
clear
that
the
majority
of
population
growth
in
both
percentage
and
total
persons
occurred
within
the
MPO
portion
of
the
county.

Percent
Urbanization
­

County
Portion
%
Urbanization
MPO
78%
non­
MPO
27%
Threshold
35%

The
MPO
portion
of
the
county
exceeds
the
percent
urbanization
threshold
while
the
non­
MPO
portion
does
not.

In
Commutes
­

Walker
County
officials
could
not
provide
data
on
the
number
of
in­
commutes
from
Walker
County
to
Hamilton
County
apportioned
by
MPO
and
non­
MPO,
but
they
did
provide
data
on
1)
number
of
persons
within
and
without
the
MPO
who
commute
to
outside
Georgia
and
2)
the
number
of
persons
within
Walker
County
who
commute
to
Hamilton
County.
The
total
number
of
persons
who
commute
to
outside
Georgia
is
9305
and
the
number
of
people
who
commute
from
Walker
to
Hamilton
is
9098.
Thus,
the
vast
majority
of
the
out­
of
state
commutes
shown
below
would
be
to
Hamilton
County.

County
Portion
Out­
of
State
Commutes
MPO
7643
non­
MPO
1662
Threshold
8913
Neither
portion
of
Walker
county
exceeds
the
in­
commute
threshold,
but
the
data
shows
that
the
majority
of
in­
commutes
into
Hamilton
County
are
from
within
the
MPO
area.
9
Vehicle
Registration
 
County
Portion
vehicle
registration
MPO
29,771
non­
MPO
29,747
Threshold
59,418
The
vehicle
registration
threshold
was
based
on
Walker
County.
These
figures
show
that
the
numbers
of
vehicles
registered
within
and
outside
the
MPO
are
about
the
same.

Vehicle
Miles
Traveled
 
County
Portion
VMT
MPO
780,045
non­
MPO
776,807
Threshold
1,557,806
The
VMT
threshold
was
based
on
Walker
County
and
this
has
no
real
meaning
in
this
portion
of
the
analysis.

Summary
of
Quantitative
Factors
 
Of
the
thresholds
that
were
not
based
on
Walker
County
itself,
the
MPO
portion
of
the
county
meets
Catoosa
County
meets
two
of
the
three
quantitative
criteria
and
the
non­
MPO
portion
meets
none.
Of
the
thresholds
that
were
based
on
Walker
County,
the
data
shows
that
there
is
much
more
commuting
to
Hamilton
County
from
the
MPO
portion
than
the
non­
MPO
portion.
Vehicle
registration
and
VMT
is
about
the
same
in
both
portions
of
the
county.

CONCLUSION
Based
on
the
above
factors
and
the
revised
L­
Scores
analysis
conducted
by
EPD,
we
conclude
that
the
portion
of
Walker
County
described
below
that
includes
the
portion
of
the
county
included
in
the
Chattanooga
MPO
be
included
in
the
Chattanooga
PM2.5
nonattainment
area.
By
including
this
portion
of
Monroe
County,
the
nonattainment
area
captures
the
vast
majority
of
PM2.5
emissions
and
precursors
from
Walker
County.
(
A
map
of
this
area
is
attached.)

From
the
west
Walker
County
line
¾
of
a
mile
south
of
Lookout
Mtn.
city
limits,
the
boundary
travels
southeast
to
the
3700
block
of
Lula
Lake
Rd.
Boundary
then
travels
south
intersecting
the
2200
block
of
Nick­
a­
Jack
Rd.
and
continues
south
1
½
miles.
Boundary
then
travels
east
to
7600
block
of
Hwy
193
at
N.
Cedar
Ln.
intersection.
Boundary
then
travels
east
following
southern
right
of
way
of
Walker
Hollow
Rd.
to
1500
block
of
N.
Marbletop
Rd.
Boundary
then
travels
southeast
intersecting
400
block
of
Childress
Hollow
Rd.
and
continuing
east
to
east
right
of
way
of
McCarty
Rd.
Boundary
then
travels
south
½
mile.
Boundary
then
travels
east
to
north
right
of
way
of
Peter
Lewis
Trl.
Boundary
then
travels
southeast
to
1100
block
of
S.
Hwy
341
at
Garretts
Chapel
Rd.
intersection.
Boundary
then
travels
southeast
to
southern
right
of
way
of
Hames
Rd.
and
Driftwood
Dr.
Boundary
then
travels
east
to
intersect
800
block
of
Lofton
Ln.
Boundary
then
travels
northeast
to
100
block
of
Glass
Mill
Rd.
at
Old
Bethel
Rd.
intersection.
Boundary
then
travels
east
along
southern
right
of
way
of
Glass
Mill
Rd.
Boundary
then
intersects
500
block
of
Old
LaFayette
Rd.
at
Glass
Mill
Rd.
intersection.
Boundary
continues
east
intersecting
9900
block
of
N.
Hwy
27,
300
block
of
10
Arnold
Rd.,
and
500
block
of
Long
Hollow
Rd.
Boundary
continues
east
to
1200
block
of
Peaving
Rd.
at
E.
Long
Hollow
Rd.
intersection.
Boundary
continues
east
along
southern
right
of
way
of
Peavine
Rd.
to
east
Walker
County
line.

We
conclude
that
because
of
its
low
Updated
L­
Score
as
calculated
by
Georgia
EPD
and
Weighted
Emissions
Score
as
calculated
by
U.
S.
EPA,
and
the
fact
that
it
meets
none
of
the
"
other"
factors,
that
Dade
County
not
be
included
in
the
Chattanooga
PM2.5
nonattainment
area.
We
conclude
that
because
of
its
low
Updated
L­
Score
as
calculated
by
Georgia
EPD
and
Weighted
Emissions
Score
as
calculated
by
U.
S.
EPA,
and
the
fact
that
of
the
five
"
other"
factors
that
exceed
the
threshold,
Catoosa
County
only
exceeds
the
threshold
by
a
small
margin,
that
Catoosa
County
not
be
included
in
the
Chattanooga
PM2.5
nonattainment
area.
11
Table
4­
A:
Emissions,
L­
scores,
and
cumulative
L­
scores
for
Walker
County.
County
SO2
NOX
VOC
NH3
Carbon
Crustal
L­
score
Cumul.
Score
Roane
92,331
30,865
4,300
285
1,230
2,988
15.57
15.57
Jackson
44,333
31,502
4,742
1,494
1,301
2,510
11.74
27.31
Floyd
33,587
16,702
7,042
108
1,298
4,442
11.54
38.85
Hamilton
5,300
20,048
27,150
1,022
872
496
8.84
47.69
Mc
Minn
10,216
10,829
5,546
1,268
1,088
1,583
6.94
54.63
Whitfield
4,380
8,910
5,719
142
1,253
1,165
6.80
61.43
Rhea
302
2,625
3,643
149
818
493
3.95
65.37
Bradley
419
4,230
7,551
1,916
442
760
3.36
68.74
De
Kalb
741
4,776
5,867
5,765
425
743
3.09
71.82
Loudon
4,035
5,899
5,338
360
310
440
2.75
74.57
Warren
1,189
1,869
3,675
446
414
624
2.57
77.14
Monroe
154
2,387
3,420
554
416
298
2.31
79.46
Walker
1,042
2,426
2,663
56
401
428
2.28
81.74
Gordon
1,129
4,170
2,891
83
348
508
2.24
83.98
Marion
477
3,156
2,640
501
308
341
1.88
85.86
Franklin
482
2,100
2,929
1,512
297
332
1.83
87.69
Fannin
142
1,082
1,122
26
380
222
1.74
89.43
Catoosa
384
3,130
2,635
74
268
339
1.72
91.15
Murray
784
2,332
1,630
41
268
295
1.54
92.69
Cherokee
143
921
1,753
111
281
137
1.42
94.11
Chattooga
2,028
2,138
1,350
29
207
231
1.34
95.45
Polk
2,066
900
949
553
155
130
0.99
96.44
Dade
174
1,954
1,046
34
147
150
0.87
97.31
Grundy
164
1,000
1,150
1,170
113
83
0.69
98.00
Meigs
112
885
871
118
100
91
0.59
98.59
Bledsoe
31
475
528
335
115
84
0.57
99.16
Sequatchie
22
304
591
173
90
46
0.46
99.62
Van
Buren
178
291
320
74
79
36
0.38
100.00
CMSA
Total
7,377
30,714
36,134
1,687
1,996
1,754
Area
Total
206,345
167,906
109,061
18,399
13,424
19,995
Table
4­
B:
2002
CERR
Inventory
for
Dade
County
Pollutant
Area
Mobile
Non­
Road
Total
Ammonia
(
tpy)
0
34.31
0.06
34.6
percent
of
total
0%
100%
0%
Nitrogen
Oxides
(
tpy)
46.95
1428.67
478.69
1954.31
percent
of
total
2%
73%
24%
Primary
PM2.5
(
tpy)
9.47
25.44
14.78
49.70
percent
of
total
19%
51%
30%
Sulfur
Dioxide
96.74
45.96
31.08
173.78
percent
of
total
56%
26%
18%
Volatile
Organic
Compounds
203.19
795.11
47.49
1045.79
percent
of
total
19%
76%
5%