ATTACHMENT
1
YEAR
2002
AIR
DISPERSION
MODELING
ANALYSIS
OF
APFO
EMISSIONS
DuPont
Washington
Works
Facility
Parkersburg,
West
Virginia
Prepared
by:

DuPont
Engineering
Technology
(
DuET)
Environmental
Section
Wilmington,
DE
19898
October
17,
2003
OPPT­
2003­
0012­
0224
RECEIVED
OPPT
NCIC
2003
October
28
8:
25AM
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
2
1.
Introduction
DuPont
conducted
air
dispersion
modeling
of
APFO 
emissions
from
its
Washington
Works
facility
located
near
Parkersburg,
WV.
Modeling
was
conducted
to
predict
long­
term
ambient
air
concentrations
of
APFO
resulting
from
actual
plant
emissions
that
occurred
during
calendar
year
2002.
This
report
describes
the
APFO
emissions
inventory
used
in
the
modeling
analysis,
the
meteorological
data,
the
dispersion
model
and
modeling
procedures,
prediction
locations
(
receptor
grid),
and
the
results
of
the
modeling
analysis.

2.
Emissions
Inventory
The
following
emission
inventory
information
has
been
assembled
in
order
to
conduct
the
air
quality
modeling:

1.
Stack
locations
2.
Stack
heights
3.
Stack
diameters
4.
Stack
gas
exit
temperatures
5.
Stack
gas
flow
rate
or
exit
velocities
6.
Detailed
plant
layout,
including
all
building
dimensions
7.
Year
2002
estimated
actual
emissions.
These
emissions
estimates
are
based
upon
product
information
and
technical
knowledge,
including
usage
factors
(
quantity
of
APFO
used
per
pound
of
dry
product),
production
records,
APFO
recovery,
and
available
stack
test
data.

All
of
the
stack
parameters
are
presented
in
Table
1,
which
shows
the
source
representation
for
modeling
purposes.
The
estimated
actual
emission
rates
of
APFO,
per
source,
are
also
presented
in
Table
1.
Figure
1
presents
the
general
locations
of
the
APFO
sources.

3.
Meteorological
Data
One
year
of
on­
site
meteorological
data
for
the
calendar
year
1996
was
used
in
this
study.
Concurrent
twice­
daily
upper
air
data
from
the
upper
air
observation
station
located
in
Wilmington,
OH
was
used
along
with
on­
site
surface
temperatures
to
obtain
hourly
mixing
depths.
Missing
data
and
measured
wind
speeds
of
less
than
1.0
m/
s
were
treated
consistent
with
the
recommendations
made
in
the
EPA's
"
Meteorological
Monitoring
Guidance
for
Regulatory
Modeling
Applications"(
1).
An
anemometer
height
of
10
meters
was
used
for
the
modeling
analysis.

4.
Model
Selection
The
area
surrounding
Washington
Works
is
primarily
non­
urban.
The
U.
S.
EPA
procedures
classify
land
use
within
3
kilometers
of
the
site
by
the
Auer
method
(
2).
Previous
review
of
U.
S.
Geological
Survey
(
USGS)
maps,
aerial
photographs,
and
site
visits
clearly
indicated
that
the
area
is
well
over
50%

 
"
APFO"
means
ammonium
perfluorooctanoate,
and
for
the
purposes
of
this
report
includes
the
anion
of
the
acid
perfluorooctanoic
acid
(
PFOA).
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
3
non­
urban.
The
Washington
Works
facility
is
located
within
the
Ohio
River
valley,
and
is
surrounded
by
significant
terrain
features
on
both
sides
of
this
river
valley.
As
a
result,
terrain
elevations
were
considered
in
the
modeling
analysis.

The
Industrial
Source
Complex
Short
Term
Model
(
ISCST3)
was
used
as
the
primary
model
to
estimate
long­
term
pollutant
concentrations.
ISCST3
is
a
steady­
state
Gaussian
model
recommended
by
the
U.
S.
EPA.
It
is
included
in
the
"
Guideline
on
Air
Quality
Models"(
3)
,
which
is
codified
as
Appendix
W
to
40
CFR
Part
51.
It
is
appropriate
for
modeling
of
pollutant
emissions
from
multiple,
industrial­
type
sources
subject
to
significant
building
downwash.
The
downwash
algorithms
in
the
ISCST3
model
provide
a
representation
of
the
aerodynamic
downwash
of
a
stack
plume
caused
by
complex
building
configurations
typical
of
industrial
facilities.
Refined
ISCST3
modeling
was
conducted
using
one
year
(
1996)
of
sequential
hourly
meteorology
from
the
from
the
on­
site
observation
facility,
as
described
above.

5.
Receptor
Selection
A
Cartesian
grid
of
receptors
was
utilized
in
this
modeling
analysis.
This
grid
consisted
of
the
following:

 
Fenceline
receptors
with
a
100
m
spacing
between
receptors
 
Receptors
beyond
the
fenceline
with
100
m
spacing
on
a
5
km
by
7
km
grid
All
receptors
are
located
along
or
outside
the
plant
fenceline.

A
Cartesian
receptor
grid
of
this
type
is
considerably
more
dense
than
recommended
by
the
U.
S.
EPA
in
the
Guidelines
on
Air
Quality
Models
for
modeling
a
facility
of
this
type.
Terrain
elevations
for
each
of
the
receptors
were
imported
from
electronic
files
obtained
from
the
U.
S.
Geological
Survey
(
USGS)
using
the
"
highest"
method
to
assign
an
elevation
to
each
receptor.
The
receptor
grid
used
in
the
modeling
analysis
is
shown
graphically
in
Figure
2.

6.
Modeling
Procedures
The
most
recent
version
of
ISCST3
(
version
02035)
was
used
in
the
air
quality
dispersion
modeling
of
all
receptors.
All
model
options
were
set
to
the
U.
S.
EPA
regulatory
default
version
of
ISCST3.
The
model
was
run
in
the
rural
mode
since
the
land
area
in
the
immediate
vicinity
of
Washington
Works
is
more
than
50%
rural.
Any
effects
of
aerodynamic
downwash
caused
by
structures
adjacent
to
the
modeled
stack
were
included
in
the
ISCST3
modeling
analysis
along
with
a
summary
of
the
building
downwash
input
files
(
BPIP).
Air
quality
dispersion
modeling
was
conducted
on
an
hour­
by­
hour
basis
using
the
one
year
of
meteorological
data
described
above.
The
APFO
modeling
results
were
summarized
for
the
annual
averaging
time
period.

7.
Results
The
results
of
the
modeling
analysis
indicate
a
maximum
predicted
annual
average
APFO
concentration
of
1.36
ug/
m3.
This
maximum
is
located
along
the
northern
property
fenceline,
along
the
Ohio
River,
at
UTM
442043
E,
4346883
N.
The
maximum
predicted
APFO
concentration
in
an
area
where
people
may
reside
is
0.39
ug/
m3.
This
prediction
is
located
at
UTM
442600
E,
4347600
N,
on
the
Ohio
side
of
the
river.
The
results
are
presented
graphically
in
Figure
3.
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
4
Table
1
***
POINT
SOURCE
DATA
***

BASE
Emission
STACK
STACK
STACK
STACK
SOURCE
X
Y
ELEV.
Rate
HEIGHT
TEMP.
EXIT
VEL.
DIAMETER
ID
(
METERS)
(
METERS)
(
feet)
(
lb/
hr)
(
feet)
(
DEG.
F)
(
ft/
sec)
(
feet)
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­
­

CEH
242
441954
4346741
659.4
0.1047
114.5
200.0
106.1
0.50
TIM
662
442025
4346847
636.5
0
149.9
172.0
40.2
1.33
TIE&
TIF
699
442091
4346836
639.8
0.1019
170.0
124.0
27.9
4.00
CFS
274
441787
4346744
656.2
0.3424
109.9
254.9
44.6
0.69
RO22EEF86
442069
4346627
629.9
0.000034
48.9
80.0
40.0
2.00
RO22EEF89
442063
4346635
629.9
0.000068
48.9
80.0
20.0
2.00
TIF
644
442084
4346835
639.8
0.4397
59.1
110.9
169.8
1.50
THI
652
441920
4346767
649.6
0.0037
69.9
200.0
54.1
1.96
CDB
216
441960
4346788
659.4
0
60.0
158.1
34.5
1.30
RO22EEF6
442086
4346624
623.4
0.0014
46.9
80.0
30.0
2.50
RO22EEF87
442058
4346634
629.9
0.00034
48.9
80.0
10.0
2.00
THG
658
441923
4346756
649.6
0.0067
67.9
299.9
22.4
1.63
CFK
268
441774
4346753
643.0
0.0071
72.5
110.0
29.1
0.27
C1CA­
D
205
442310
4346800
656.2
0
6.7
70.0
84.9
0.50
CDT
231
441953
4346766
659.4
0.3622
81.0
130.0
28.4
0.67
CDW
232
441952
4346776
659.4
0.2626
93.2
130.0
23.6
0.67
TIV
697
442129
4346836
656.0
0.0049
45.0
66.0
15.2
1.67
TIF
694
442104
4346822
656.0
9.50E­
03
45.0
66.0
15.2
1.67
TIE
647
442125
4346818
656.0
0.0033
69.0
230.0
57.0
1.67
TIF
648
442109
4346805
656.0
0.0024
69.0
230.0
57.0
1.67
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
5
Figure
1
Source
and
Building
Locations
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
6
Figure
2
Receptor
Grid
Used
in
the
Modeling
Analysis
439000
440000
441000
442000
443000
444000
445000
meters
4345000
4346000
4347000
4348000
4349000
meters
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
7
439000
440000
441000
442000
443000
444000
445000
meters
4345000
4346000
4347000
4348000
4349000
meters
Figure
3
APFO
2002
Modeled
Emissions
Annual
Average
Concentrations
(
ug/
m3)

Contour
Interval
0.1
ug/
m3
Year
2002
Air
Dispersion
Modeling
Analysis
October
17,
2003
Page
8
References
(
1)
U.
S.
EPA,
Meteorological
Monitoring
Guidance
for
Regulatory
Modeling
Applications,
EPA­
454/
R­
99­
005,
Office
of
Air
Quality
Planning
and
Standards,
February,
2000.

(
2)
Auer,
A.
H.,
"
Correlation
of
Land
Use
Cover
with
Meteorological
Anomalies",
Journal
of
Applied
Meteorology,
Vol.
17,
pp.
636­
643,
1978.

(
3)
U.
S.
EPA,
Guideline
on
Air
Quality
Models
(
Revised),
EPA­
450/
2­
78­
027R­
C,
2001.
