Document ID: EPA-HQ-OAR-2003-0083-1360
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-03-19T05:00Z

North
Carolina
Recommendation
for
Chatham
County
The
purpose
of
this
paper
is
to
discuss
the
rationale
for
recommending
the
township
boundaries
of
Baldwin,
Center,
New
Hope,
and
Williams
in
Chatham
County,
rather
than
the
entire
county
or
the
entire
Metropolitan
Statistical
Area
as
nonattainment
for
the
8­
hour
ozone
standard.

 
First,
with
a
design
value
in
2000­
2002
of
0.083
ppm,
and
a
design
value
in
2001­
2003
of
0.082
ppm
at
Pittsboro
site,
this
area
already
meets
the
8­
hour
ozone
standard.
 
Second,
the
population
densities
are
not
created
equal.
Most
of
the
southwest
part
of
the
Chatham
County
has
very
low
population
density
(
except
Siler
City)
and
only
the
northeast
part
of
the
Chatham
County,
which
borders
Wake,
Durham,
and
Orange
Counties,
has
relatively
higher
population
density.
The
population
in
Chatham
County
grew
by
27.3%
between
1990
(
38,759
people)
and
2000
(
49,329
people),
and
is
expected
to
grow
by
21.8%
between
2000
and
2010
(
projected
60,060
people).
Most
of
the
population
growth
in
Chatham
County
is
in
the
area
bordering
Durham
and
Orange
Counties.
In
contrast,
Wake
County's
population
grew
by
47.3%
between
1990
(
426,301
people)
and
2000
(
627,846
people),
and
is
expected
to
grow
by
36.5%
between
2000
and
2010
(
projected
857,054
people).
The
population
density
in
Chatham
County
is
typically
0­
50
persons
per
square
mile.
 
Third,
back
trajectories
on
the
days
when
the
Pittsboro
monitor
is
violating
trace
to
the
Triangle
region,
Charlotte,
Triad
or
Virginia
on
the
all
(
total
13)
but
2
of
the
8­
hour
exceedance
days
in
2000,
2001,
and
2002.
 
The
majority
of
the
NOx
emissions
in
Chatham
County
are
generated
from
point
and
mobile
sources
(
19.67
tons
per
day
from
point
and
an
additional
4.74
tons
per
day
from
mobile
out
of
the
total
28.08
tons
per
day).
The
Cape
Fear
Steam
Station
will
be
reducing
NOx
emissions
under
both
the
NOx
SIP
Call
and
the
Clean
Smokestacks
Act.
The
Federal
and
state
mobile
strategies
will
reduce
mobile
emission.
The
I/
M
program
will
be
implemented
in
Chatham
Counties
by
January
2004.
Low
sulfur
gasoline
will
be
required
statewide.
For
these
mobile
sources,
North
Carolina
has
already
adopted
the
only
available
strategy.
Future
year
modeling
for
2007
indicates
that
all
of
the
Triangle
region
is
expected
to
attain
the
8­
hour
ozone
standard
with
these
Federal
and
State
control
programs.
 
Finally,
North
Carolina
continues
to
believe
this
is
an
appropriate
boundary
for
this
region
which
already
meets
the
8­
hour
ozone
standard.