UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON
D.
C.,
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
PC
Code:
128840,
128848,
129023
DP
Barcode:
D313182
Date:
Jun
21,
2005
MEMORANDUM
SUBJECT:
Drinking
Water
Assessment
for
Imazaquin
and
its
Salts
TO:
Craig
Doty,
Chemical
Review
Manager
Special
Review
Branch
Special
Review
and
Registration
Division
(
7508C)

FROM:
Keara
Moore,
Environmental
Scientist
Environmental
Risk
Branch
III
Environmental
Fate
and
Effects
Division
(
7507C)

THROUGH:
Mark
Corbin,
Senior
Environmental
Scientist
Environmental
Risk
Branch
III
Environmental
Fate
and
Effects
Division
(
7507C)

APPROVED
BY:
Daniel
Rieder,
Branch
Chief
Environmental
Risk
Branch
III
Environmental
Fate
and
Effects
Division
(
7507C)

Summary
This
document
reports
the
Tier
II
estimated
environmental
concentrations
(
EEC)
in
drinking
water
to
support
the
tolerance
reassessment
process
for
imazaquin
[
2­(
4­
Isopropyl­
4­
methyl­
5­
oxo­
2­
imidazolin­
2­
yl­
3­
quinolinecarboxylic
acid;
PC
128848]
and
its
monoammonium
and
monosodium
salts
(
PC
128840
&
129023).
Because
all
three
compounds
dissociate
in
water
to
form
the
carboxylate
anion,
they
are
treated
concurrently
in
the
following
assessment.
Except
where
otherwise
noted,
"
imazaquin"
will
be
used
to
refer
to
all
three
compounds.
At
this
time,
no
degradates
of
concern
have
been
identified
and
only
the
parent
compounds
will
be
considered
in
this
assessment.
Imazaquin's
primary
use
is
as
a
broad
spectrum
herbicide
on
soybeans.
The
turf
and
ornamental
use
patterns
are
also
considered
in
this
assessment.
2
Concentrations
of
imazaquin
to
which
humans
potentially
may
be
exposed
through
ingestion
of
drinking
water
are
assessed
through
an
evaluation
of
surface
water
and
groundwater
monitoring
data
and
modeling.
Surface
and
groundwater
monitoring
data
were
available
from
the
United
States
Geological
Survey
(
USGS)
National
Water­
Quality
Assessment
(
NAWQA)
Program
and
from
an
additional
USGS
study
on
pesticide
concentrations
in
high
use
areas
in
the
Midwest.
Maximum
concentrations
of
imazaquin
in
the
monitoring
data
reviewed
were
4.89
:
g
ae/
L
in
surface
water
and
0.098
:
g
ae/
L
in
groundwater.
Because
the
monitoring
studies
reviewed
are
short
term
or
not
targeted
to
detect
imazaquin,
they
are
not
likely
to
capture
peak
concentrations.
Modeling
is
used,
therefore,
to
predict
the
most
conservative
concentrations,
with
monitoring
data
used
to
confirm
that
modeling
results
are
reasonable.
EECs
in
surface
water
were
modeled
using
PRZM
3.12/
EXAMS
2.98.04
and
ground
water
concentrations
were
modeled
using
SCIGROW
(
version
2.3).
These
results
are
presented
in
Table
1.
Note
that
all
concentrations
reported
in
this
assessment
are
in
acid
equivalents
(
ae)
unless
otherwise
specified.

Table
1.
Imazaquin
EECs
Surface
water
(
PRZM
/
EXAMS)
Groundwater
(
SCIGROW)

Acute
(
Peak)
Chronic
(
Annual
average)
Acute
&
Chronic
Soybeans
Turf
­
1
app.
Turf
­
2
app.
Ornamental
1.8
µ
g
ae/
L
15.2
µ
g
ae/
L
20.0
µ
g
ae/
L
17.4
µ
g
ae/
L
0.4
µ
g
ae/
L
5.0
µ
g
ae/
L
7.6
µ
g
ae/
L
9.1
µ
g
ae/
L
3.8
µ
g
ae/
L
15.6
µ
g
ae/
L
31.1
µ
g
ae/
L
15.6
µ
g
ae/
L
Pesticide
Use
and
Application
Imazaquin
is
a
broad
spectrum
herbicide
used
primarily
on
soybeans
with
other
minor
food
uses
that
include
dry
beans,
lima
beans,
corn,
and
peas.
It
is
also
used
on
turf
in
both
commercial
and
residential
settings
and
on
ornamental
trees,
shrubs,
and
groundcover.
Imazaquin
has
a
number
of
formulations
including
Scepter,
Squadron,
Detail
and
Backdraft
for
soybeans
and
Image
for
turf
and
ornamentals.
The
registrant
states
that
production
of
all
row
crop
products
except
Scepter
70DG
(
Reg.
No.
241­
306)
has
been
discontinued.
Image
formulations
(
Reg.
Nos.
241­
319
and
241­
351)
are
still
marketed.
Based
on
data
from
1998
through
2003,
200,000
lbs
of
imazaquin
were
used
annually
on
soybeans
relative
to
less
than
500
lbs
for
the
other
minor
food
uses
(
BEAD,
2005),
so
soybeans
(
Scepter
70DG)
are
the
only
food
use
simulated
for
this
document.
Sales
of
Image
products
for
use
on
turf
and
ornamentals
are
approximately
10%
of
total
sales,
on
a
pound
a.
i.
basis
(
Imazaquin
Sales
Report).
Both
turf
and
ornamental
uses
are
simulated.

Use
of
imazaquin
on
soybeans
is
limited
by
the
label
to
the
eastern
half
of
the
United
States.
Figure
1
presents
a
summary
of
total
agricultural
imazaquin
use,
created
by
the
NAWQA
Pesticide
National
Synthesis
Project
(
USGS,
2003).
This
map
is
based
on
state­
level
estimates
of
pesticide
use
rates
for
individual
crops,
which
have
been
compiled
by
the
National
Center
for
Food
and
Agricultural
Policy
(
NCFAP)
for
1995­
1998,
and
on
1997
Census
of
Agriculture
county
crop
acreage.
Imazaquin
can
only
be
used
on
turf
in
the
southern
U.
S.
because
of
the
lack
of
selectivity
for
cool
season
grasses
(
Reg.
Nos.
241­
319
and
241­
351).
There
is
no
geographic
limitation
on
use
for
ornamentals,
although
imazaquin
is
not
to
be
used
on
field
or
tree
nurseries
(
Reg.
No.
241­
351).
These
uses
are
not
represented
in
Figure
1.
3
Figure
1.
Estimated
annual
agricultural
use
of
imazaquin
based
on
1995
­
1998
data.
4
On
soybeans,
imazaquin
may
be
applied
preplant
incorporated,
preemergence,
postemergence,
or,
in
some
regions,
in
the
late
fall
after
harvest.
It
can
be
applied
aerially
or
by
ground
spray.
The
maximum
single
application
rate
for
Scepter
70DG
is
0.1225
lb/
A.
At
the
time
of
previous
imazaquin
assessments,
two
applications
were
allowed
annually,
but
as
of
2002,
labeled
use
of
Scepter
70DG
has
been
limited
to
one
application
per
year.
On
turf,
imazaquin
is
applied
as
ground
spray
and
the
maximum
single
application
rate
is
0.5
lb/
A.
Image
labels
do
not
indicate
a
maximum
number
of
applications
per
year
and
indicate
that
for
control
of
difficult
weeds
in
turf,
more
than
one
application
may
be
necessary.
The
registrant
states,
however,
that
only
one
application
of
imazaquin
is
used
annually
on
turf.

Environmental
Fate
and
Transport
Characterization
Imazaquin
is
an
imidazole
compound
that
is
highly
mobile
(
median
K
oc
=
17.5)
and
non­
volatile
(
vapor
pressure
<
2E­
8
torr;
MRID
146197).
In
terrestrial
environments
it
is
persistent
(
aerobic
t
1/
2
=
7
months,
anaerobic
t
1/
2
=
stable;
MRIDs
131564
and
146212).
In
aquatic
environments,
imazaquin
is
stable
to
hydrolysis
at
all
pH
levels
(
MRID
131546)
and
it
experiences
rapid
photolysis
(
t
1/
2
=
<
1day;
MRID
146209);
there
are
no
data
available,
however,
regarding
aquatic
metabolism.
Based
on
these
properties,
imazaquin
has
been
identified
as
a
compound
likely
to
be
persistent
with
a
high
leaching
potential.
In
the
one
available
field
dissipation
study,
imazaquin
residues
were
found
through
the
entire
36
inch
depth
of
the
sampling
area
3
days
after
application,
following
a
rain
event
(
MRID
43019802).
Rain
or
irrigation
following
application
is
required
to
assure
the
effectiveness
of
imazaquin,
so
this
rain
event
does
not
invalidate
the
field
results
(
Reg.
Nos.
241­
306,
319).
The
primary
degradates
resulting
from
aerobic
soil
metabolism
were
carbon
dioxide,
CL
266,066
(
a
closely
related
decarboxylation
product),
and
up
to
six
other
minor,
unidentified
compounds.

Monitoring
Data
Existing
monitoring
data
considered
in
this
assessment
were
the
NAWQA
groundwater
and
surface
water
database
(
USGS,
2004)
and
a
study
done
by
the
USGS
on
pesticide
contamination
in
Midwestern
groundwater
and
surface
water
(
Battaglin
et
al,
2001).

Surface
Water
The
NAWQA
program
began
in
1991
as
an
effort
by
the
USGS
to
catalog
the
quality
of
water
resources
in
the
United
States
by
collecting
surface
and
groundwater
data
in
selected
watersheds.
Chemical,
biological
and
physical
water
quality
parameters
are
measured
at
59
study
units
across
the
United
States.
Imazaquin
was
added
as
an
analyte
in
2001.
Between
5/
1/
01
and
9/
30/
03,
943
surface
water
samples
were
collected
at
70
different
locations.
There
were
detections
of
imazaquin
in
158
(
17%)
of
these
samples,
collected
at
30
sites.
108
detections
at
25
sites
were
at
levels
greater
than
the
limit
of
quantitation
(
LOQ)
of
0.016
:
g/
L.
The
maximum
detection
was
4.89
:
g/
L
and
the
95th
percentile
level
was
0.07
:
g/
L.

NAWQA's
monitoring
network
is
national,
and
does
not
target
specific
pesticides
or
use
patterns.
Only
41
of
the
sites
sampled
(
604
samples)
are
within
the
area
labeled
for
application
of
5
Figure
2.
Location
and
type
of
USGS
sampling
sites.
imazaquin
on
soybeans.
6
of
the
sites
with
imazaquin
detections
lie
outside
of
this
soybean
use
region.
Additionally,
only
4
of
the
locations
with
imazaquin
detections
are
in
agricultural
areas;
the
other
sites
are
designated
as
urban
(
13),
mixed
(
10),
or
other
(
3).
The
highest
surface
water
concentration
found
was
in
Durham,
Oregon,
a
suburb
of
Portland
where
the
primary
land
uses
are
residential
and
parks.
This
would
suggest
an
impact
from
the
turf
use,
but
none
of
the
grasses
to
which
imazaquin
is
applied
are
grown
in
this
region.
This
site
is
in
the
Willamette
Basin,
however,
a
major
producer
of
ornamental
trees.
The
7
sites
with
the
highest
maximum
values
are
in
urban
locations,
indicating
that
the
turf
and
ornamental
use
patterns
may
contribute
significantly
to
runoff
concentrations.

In
1998,
the
USGS
conducted
another
study
specifically
aimed
at
investigating
imidazole
and
sulfonylurea
pesticides
(
Battaglin,
2001).
This
study
includes
surface
water
samples
from
71
stream
locations
and
5
reservoir
locations
in
10
Midwestern
states,
as
shown
in
Figure
2.
Sites
were
selected
to
target
high
agricultural
pesticide
use
areas
while
still
capturing
population
variability.
Two
samples
were
taken
at
each
site;
at
stream
sites,
the
first
sample
was
taken
after
preemergent
pesticide
application
and
following
a
precipitation
event
and
the
second
after
post­
emergent
pesticide
application,
again
following
a
precipitation
event.
Reservoir
samples
were
taken
2­
3
weeks
following
stream
samples.
41
stream
samples
and
8
reservoir
samples
had
detections
above
the
method
reporting
limit
(
MRL)
of
0.010
:
g/
L,
with
a
maximum
of
1.1
:
g/
L,
a
median
of
<
0.010
:
g/
L,
and
a
95th
percentile
value
of
0.2
:
g/
L.
16
of
the
sites,
including
6
in
Indiana,
4
in
Ohio,
and
3
in
Illinois,
had
detections
at
both
sampling
events.

Groundwater
The
NAWQA
program
also
includes
groundwater
monitoring.
Between
5/
1/
01
and
9/
30/
03,
1004
samples
from
998
sites
were
tested
for
imazaquin.
There
were
18
detections,
7
above
the
LOQ
of
0.016
:
g/
L.
Detections
ranged
from
0.019
to
0.098
:
g/
L,
the
maximum
from
either
study.
60%
of
the
measured
NAWQA
groundwater
samples
were
collected
in
states
listed
as
use
areas
on
the
label
for
Scepter
70DG.
There
were,
however,
detections
in
Hawaii,
New
York,
and
California,
states
not
listed
on
the
Scepter
70DG
label
or
on
the
labels
of
discontinued
agricultural
imazaquin
products.
As
with
the
surface
water,
several
of
the
detections
were
in
areas
designated
urban
(
3)
or
mixed
(
4).
6
In
the
USGS
1998
pesticide
monitoring
program
(
Battaglin,
2001),
single
samples
were
taken
at
25
wells,
20
in
Iowa
and
5
in
northern
Illinois,
as
shown
in
Figure
2.
At
the
majority
of
these
wells,
the
depth
to
the
top
of
the
well
screen
ranged
from
6
to
30
m
deep
while
the
rest
of
the
wells
sampled
were
as
deep
as
83
m.
As
with
the
surface
water
monitoring
study,
these
wells
were
selected
in
high
pesticide
use
areas,
and
so
are
not
intended
as
non­
targeted
samples.
Detections
at
or
above
the
MRL
of
0.010
:
g/
L
were
found
at
3
of
the
25
wells,
with
levels
of
0.010,
0.012,
and
0.024
:
g/
L.

Exposure
Modeling
Surface
Water
To
determine
Tier
II
EECs
in
surface
water,
the
Pesticide
Root
Zone
Model
(
PRZM
3.12;
5/
7/
98),
which
simulates
transport
off
the
agricultural
field,
is
run
in
tandem
with
the
Exposure
Analysis
Modeling
System,
(
EXAMS
2.98.04;
6/
13/
97),
which
simulates
the
fate
of
chemicals
in
the
water
body.
These
are
operated
using
the
pe4v01
shell
program
(
8/
13/
03).
Additional
information
about
these
models
can
be
found
at
the
EPA's
water
modeling
website,
http://
www.
epa.
gov/
oppefed1/
models/
water/.
The
simulated
watershed
is
based
on
an
Index
Reservoir
(
IR)
scenario,
and
a
percent
cropped
area
(
PCA)
adjustment
factor
is
used
to
adjust
for
the
area
within
the
watershed
that
is
planted
to
the
modeled
crop
(
OPP,
2000).
Models
are
run
for
multiple
(
usually
30)
years
and
the
reported
EECs
represent
the
values
that
are
expected
once
every
ten
years,
based
on
the
thirty
years
of
daily
values
generated
during
the
simulation.

The
crop
scenarios
used
by
PRZM/
EXAMS
represent
sites
that
are
highly
vulnerable
to
runoff.
In
this
assessment,
the
Mississippi
soybean,
Florida
turf,
and
Oregon
Christmas
tree
scenarios
were
used
(
EFED,
2003).
The
Mississippi
soybean
scenario
is
located
in
Yazoo
County,
MS,
one
of
the
highest
use
areas
depicted
in
Figure
1.
Geographic
information
about
usage
of
imazaquin
on
turf
is
not
available,
but
Florida
does
lie
within
the
expected
imazaquin
use
region
for
turf.
The
Oregon
Christmas
tree
scenario
is
used
as
a
surrogate
for
the
ornamental
use
pattern.
The
scenario
is
located
in
Benton
County,
in
the
same
watershed
as
the
highest
surface
water
detection.

The
model
input
parameter
values
used,
selected
in
accordance
with
EFED's
input
parameter
guidance
(
EFED,
2002),
are
presented
in
Table
2.
The
application
rate
used
represents
the
maximum
label
rate
and
when
multiple
possible
application
methods
were
available,
the
one
that
resulted
in
the
most
conservative
EEC
was
chosen.
The
turf
use
is
simulated
with
a
single
annual
application,
as
stated
by
the
registrant,
and
with
multiple
applications,
as
allowed
by
the
label.
Half­
lives
are
based
on
registrant­
submitted
data.
The
PRZM/
EXAMS
input
files
are
provided
in
Appendix
A
and
the
output
files
in
Appendix
B.
Based
on
modeling
results,
for
soybeans
EFED
estimates
an
acute
surface
water
EEC
of
1.8
µ
g
ae/
L
and
a
chronic
EEC
of
0.4
µ
g
ae/
L.
For
turf,
at
one
application
per
year,
the
acute
surface
water
EEC
is
15.2
µ
g
ae/
L
and
the
chronic
EEC
is
5.0
µ
g
ae/
L,
while
for
two
applications,
the
acute
EEC
is
20.0
µ
g
ae/
L
and
the
chronic
EEC
is
7.6
µ
g
ae/
L.
The
acute
EEC
for
ornamentals
is
17.4
µ
g
ae/
L
and
the
chronic
EEC
is
9.1
µ
g
ae/
L.
7
Table
2.
PRZM/
EXAMS
Input
Parameters
for
Imazaquin
Drinking
Water
Assessment
Model
Parameter
Value
Comments
Source
Application
Rate
per
Event
Soybeans:
0.14
kg/
ha
Turf
/:
0.56
kg/
ha
Ornamentals
Label
241­
306
Labels
241­
319,
351
Application
Dates
Soybeans:
April
10
Turf
/
:
April
1,
Ornamentals
(
April
29)
1
app/
yr
Unspecified
apps/
yr;
Typical
use
=
late
spring
Label
241­
319,
351
Spray
Drift
by
Scenario
Soybeans:
16
%

Turf
/:
6.4
%
Ornamentals
Soybeans:
Aerial
Turf
:
Ground
Label
241­
306
Labels
241­
319,
351
Crop
Application
Method
Soybeans:
Soil
applied
Turf
:
Foliar
Incorporation
Depth
Soybeans:
0
cm
Turf
/
:
0
cm
Ornamentals
Aerobic
Soil
Metabolism
Half­
Life
630
days
3
times
single
reported
value
MRID
131564
Anaerobic
Soil
Metabolism
Half­
Life
Stable
MRID
146212
Aerobic
Aquatic
Degradation
Half­
life
1260
days
No
reported
data
2
times
Aerobic
Soil
Metabolism
Half­
life
Anaerobic
Aquatic
Degradation
Half­
life
Stable
No
reported
data
Assume
½
of
anaerobic
soil
rate
or
stable
Aqueous
Photolysis
Half­
life
0.9
day
MRID
146209
Hydrolysis
Half­
life
Stable
MRID
131546
Koc
17.5
ml/
g
Median
of
4
values
MRID
131564
Molecular
Weight
311.34
Product
Chemistry
Water
Solubility
6000
mg/
l
10
times
reported
value
Product
Chemistry
Vapor
Pressure
<
2
x
10­
8
torr
Product
Chemistry
Percent
Cropped
Area
(
PCA)
Soybeans:
0.41
Turf
/
:
1
Ornamentals
8
Groundwater
EECs
for
groundwater
were
generated
with
SCIGROW
2.3
(
EFED,
2001b),
a
screening
tool
for
groundwater
used
as
drinking
water.
SCIGROW
was
developed
by
regressing
the
results
of
Prospective
Ground
Water
studies
against
the
Relative
Index
of
Leaching
Potential
(
RILP).
The
RILP
is
a
function
of
aerobic
soil
metabolism
and
the
soil­
water
partition
coefficient.
The
output
of
SCIGROW
represents
the
concentrations
that
might
be
expected
in
shallow
unconfined
aquifers
under
sandy
soils.

As
with
surface
water
modeling,
model
input
parameter
values
used
in
SCIGROW
were
selected
in
accordance
with
EFED's
input
parameter
guidance
(
Environmental
Fate
and
Effects
Division,
2002).
These
input
parameters,
presented
in
Table
3,
represent
the
total
residues
of
flazasulfuron
at
the
maximum
label
application
rate.
The
acute
and
chronic
concentrations
of
total
residues
of
flazasulfuron
in
shallow
groundwater
predicted
by
SCIGROW
under
these
conditions
are
3.8
µ
g
ae/
L
for
soybeans,
15.6
µ
g
ae/
L
for
a
single
application
on
turf
or
ornamentals,
and
31.1
µ
g
ae/
L
for
two
applications
on
turf.
The
SCIGROW
input
and
output
files
are
provided
in
Appendix
C.

Table
3.
SCIGROW
Input
Parameters
for
Total
Residues
of
Imazaquin
Model
Parameter
Input
Value
Source
Comments
Aerobic
Soil
Metabolism
Half­
Life
210
days
MRID
131564
KOC
17.5
mL/
g
MRID
131564
Median
of
4
values
Application
Rate
Soybeans:
0.12
lb/
A
Turf
:
0.5
lb/
A
Label
241­
306
Labels
241­
319,
351
Applications
Per
Year
Soybeans:
1
Turf
:
1
or
2
Label
241­
306
Labels
241­
319,
351
Unspecified
app
/
yr
Uncertainty
The
drinking
water
assessment
for
imazaquin
relied
on
both
an
analysis
of
monitoring
data
and
modeling
to
predict
potential
concentrations
to
which
humans
may
be
exposed.
There
are
uncertainties
in
this
assessment
for
both
types
of
analysis.

Modeling
relies
on
estimated
fate
parameters
and
assumed
agricultural
practices
to
predict
concentrations
of
imazaquin
to
which
humans
may
be
exposed.
In
this
instance,
there
were
fate
data
available
for
all
processes
except
aquatic
metabolism.
Half­
life
values
for
aerobic
and
anaerobic
metabolism
were
estimated
based
on
EFED
guidance
(
EFED,
2002).
This
data
gap
adds
some
uncertainty
to
the
assessment,
but
it
is
limited
because
soil
metabolism
is
expected
to
be
the
primary
route
of
degradation.
Only
a
single
study
value
was
available
to
assess
soil
metabolism.
In
order
to
insure
than
an
EEC
is
predictive
of
all
populations,
this
value
was
9
multiplied
by
three
to
estimate
an
upper
90th
percentile.
There
were
no
acceptable
data
available
from
terrestrial
field
dissipation
studies
to
compare
with
the
estimated
half­
lives.

PRZM/
EXAMS
requires
information
on
agricultural
practices
as
inputs,
such
as
specific
application
dates
and
rates
to
be
applied.
In
reality,
application
dates
and
rates
applied
across
the
United
States
will
vary
depending
on
geography,
pest
pressure,
climatic
factors,
and
changes
in
agricultural
cropping
patterns.
EFED
attempts
to
capture
some
of
this
variability
by
modeling
as
many
representative
scenarios
as
possible
and
by
using
meteorological
data
which
covers
a
time
span
sufficient
to
capture
climatic
variations
which
are
likely
to
occur.
However,
the
model
is
limited
in
its
ability
to
capture
all
of
the
natural
variation
which
occurs
for
any
pesticide
application
and
this
adds
uncertainty
to
the
drinking
water
assessment.
This
is
of
particular
importance
for
the
turf
scenario,
because
in
this
case,
the
application
date
of
the
pesticide
is
not
limited
to
a
specific
planting
season.
It
can
be
applied
most
of
the
year,
especially
in
areas
like
that
modeled,
where
winter
dormancy
is
not
expected.
Another
factor
important
in
estimating
runoff
and
leaching
from
turf
scenarios
is
the
number
of
applications.
The
label
does
not
limit
the
number
of
applications
and
specifically
states
that
more
than
one
may
be
necessary,
although
the
registrant
states
that
typical
use
is
a
single
application.
This
assessment
shows
the
estimated
concentration
increase
resulting
from
a
second
application,
and
additional
applications
would
result
in
further
increases.

There
is
additional
uncertainty
in
the
EECs
for
turf
and
ornamentals
because
there
is
no
PCA
available
for
these
uses.
No
adjustment
was
applied
to
the
turf
and
ornamental
EECs,
thereby
indicating
the
assumption
that
imazaquin
is
applied
to
the
entire
watershed.
The
choice
of
scenarios
modeled
adds
further
uncertainty
to
the
ornamental
EEC.
The
Oregon
Christmas
tree
scenario
is
not
designed
to
specifically
represent
the
trees
and
shrubs
on
which
imazaquin
is
applied.
Because
it
simulates
the
soil
and
crop
conditions
of
a
woodland
environment,
it
was
selected
as
the
most
appropriate
scenario
available.
A
PCA
of
0.41
is
applied
to
soybeans,
based
on
the
maximum
cropped
percentage
in
soybean
use
areas.
It
does
not
take
into
account
the
fact
that
applications
of
imazaquin
may
be
made
to
soybeans
and
turf
in
the
same
watershed.

EFED
has
relied
on
an
evaluation
of
monitoring
data
for
imazaquin
collected
by
others.
Each
monitoring
data
set
evaluated
in
this
assessment
was
collected
with
a
different
study
objective.
The
NAWQA
data
represents
surface­
water
and
groundwater
concentrations
collected
on
a
national
basis
with
an
emphasis
on
high
agricultural
use
areas.
The
USGS
study
is
targeted
to
pesticide
use,
but
imazaquin
is
one
of
a
large
group
considered.

Imazaquin
has
been
detected
in
both
surface
water
and
groundwater.
However,
none
of
these
monitoring
data
were
specifically
targeted
to
imazaquin
use.
Non­
targeted
monitoring
data
is
typically
used
by
EFED
as
a
check
against
modeling
estimates
and
not
as
drinking
water
estimates
for
use
in
the
human
health
dietary
assessment.
Many
of
the
sample
locations
included
in
the
reviewed
monitoring
data
sets
were
not
targeted
to
areas
of
highest
imazaquin
use
and
consequently,
extrapolation
of
concentrations
of
imazaquin
in
groundwater
and
surface
water
from
these
data
may
not
be
representative
of
concentrations
in
all
areas
of
highest
imazaquin
use.
It
is
important
to
note
that
there
were
a
number
of
detections
in
locations
not
expected
to
be
high
imazaquin
use
areas.
10
The
frequency
of
sampling
from
the
monitoring
data
evaluated
also
adds
uncertainty
to
this
assessment.
Estimates
from
monitoring
data
of
acute
exposure
have
varying
sample
frequencies
and
it
is
unclear
what
effect
this
has
on
peak
estimates
from
monitoring
data.
Therefore,
it
is
likely
that
the
monitoring
data
has
not
captured
the
maximum
peak
concentration
from
the
locations
sampled.
This
fact,
coupled
with
the
fact
that
monitoring
data
are
not
targeted
to
imazaquin
use
areas,
adds
uncertainty
to
the
estimation
of
EECs
from
the
monitoring
data.

County
level
use
data
for
imazaquin
data
have
been
derived
from
an
approach
developed
by
Thelin
and
Gianessi,
2000.
In
this
approach
Thelin
and
Gianessi
relied
on
a
combination
of
state
level
pesticide
use
data
derived
from
the
National
Center
on
Food
and
Agricultural
Policy
(
NCFAP)
and
county
level
information
on
harvested
crop
acreage
taken
from
the
USDA
Census
of
Agriculture.
This
approach
is
limited
by
the
fact
that
state
level
coefficients
of
pesticide
use
cannot
provide
precise
county
level
estimates
and
do
not
account
for
local
variations
in
cropping
and
management
practices.
Finally,
the
approach
is
limited
in
that
the
Census
of
Agriculture
may
under­
report
certain
crops
and
regions
due
to
non­
disclosure.
All
of
these
factors
add
uncertainty
to
the
assessment.
11
Appendix
A:
PRZM/
EXAMS
Input
Files
12
Mississippi
Soybean
MS
soybean;
8/
9/
01
"
Yazoo
Co.
MLRA
134;
Metfile:
W13893.
dvf
(
old:
Met134.
met),"
***
Record
3:
0.75
0.25
0
17
1
3
***
Record
6
­­
ERFLAG
4
***
Record
7:
0.42
0.0151
1
172.8
3
2
600
***
Record
8
1
***
Record
9
1
0.2
30
100
3
87
84
86
0
76
***
Record
9a­
d
1
27
0101
1601
0102
1602
0103
1603
0104
1604
2004
0105
0505
1605
0106
1606
0107
1607
.245
.276
.306
.337
.373
.418
.468
.498
.575
.627
.654
.620
.484
.361
.220
.094
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
0108
1608
0109
1609
0110
1510
1610
0111
1611
0112
1612
.109
.110
.046
.053
.040
.203
.239
.316
.394
.464
.524
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
.014
***
Record
10
­­
NCPDS,
the
number
of
cropping
periods
30
***
Record
11
150461
010961
101061
1
150462
010962
101062
1
150463
010963
101063
1
150464
010964
101064
1
150465
010965
101065
1
150466
010966
101066
1
150467
010967
101067
1
150468
010968
101068
1
150469
010969
101069
1
150470
010970
101070
1
150471
010971
101071
1
150472
010972
101072
1
150473
010973
101073
1
150474
010974
101074
1
150475
010975
101075
1
150476
010976
101076
1
150477
010977
101077
1
150478
010978
101078
1
150479
010979
101079
1
150480
010980
101080
1
150481
010981
101081
1
150482
010982
101082
1
150483
010983
101083
1
150484
010984
101084
1
150485
010985
101085
1
150486
010986
101086
1
150487
010987
101087
1
150488
010988
101088
1
13
150489
010989
101089
1
150490
010990
101090
1
***
Record
12
­­
PTITLE
imazaquin
­
1
applications
@
.14
kg/
ha
***
Record
13
30
1
0
0
***
Record
15
­­
PSTNAM
imazaquin
***
Record
16
100461
0
1
0.0
0.14
0.84
0.16
100462
0
1
0.0
0.14
0.84
0.16
100463
0
1
0.0
0.14
0.84
0.16
100464
0
1
0.0
0.14
0.84
0.16
100465
0
1
0.0
0.14
0.84
0.16
100466
0
1
0.0
0.14
0.84
0.16
100467
0
1
0.0
0.14
0.84
0.16
100468
0
1
0.0
0.14
0.84
0.16
100469
0
1
0.0
0.14
0.84
0.16
100470
0
1
0.0
0.14
0.84
0.16
100471
0
1
0.0
0.14
0.84
0.16
100472
0
1
0.0
0.14
0.84
0.16
100473
0
1
0.0
0.14
0.84
0.16
100474
0
1
0.0
0.14
0.84
0.16
100475
0
1
0.0
0.14
0.84
0.16
100476
0
1
0.0
0.14
0.84
0.16
100477
0
1
0.0
0.14
0.84
0.16
100478
0
1
0.0
0.14
0.84
0.16
100479
0
1
0.0
0.14
0.84
0.16
100480
0
1
0.0
0.14
0.84
0.16
100481
0
1
0.0
0.14
0.84
0.16
100482
0
1
0.0
0.14
0.84
0.16
100483
0
1
0.0
0.14
0.84
0.16
100484
0
1
0.0
0.14
0.84
0.16
100485
0
1
0.0
0.14
0.84
0.16
100486
0
1
0.0
0.14
0.84
0.16
100487
0
1
0.0
0.14
0.84
0.16
100488
0
1
0.0
0.14
0.84
0.16
100489
0
1
0.0
0.14
0.84
0.16
100490
0
1
0.0
0.14
0.84
0.16
***
Record
17
0
1
0
***
Record
19
­­
STITLE
"
The
Loring,
silt
loam,
HYDG
C"
***
Record
20
155
0
0
1
0
0
0
0
0
0
***
Record
26
0
0
0
***
Record
30
4
17.5
***
Record
33
6
1
13
1.4
0.385
0
0
0
0.0011
0.0011
0
0.1
0.385
0.151
2.18
0
14
2
23
1.4
0.37
0
0
0
0.0011
0.0011
0
1
0.37
0.146
0.49
0
3
33
1.4
0.37
0
0
0
0.0011
0.0011
0
3
0.37
0.146
0.16
0
4
30
1.45
0.34
0
0
0
0.0011
0.0011
0
5
0.34
0.125
0.124
0
5
23
1.49
0.335
0
0
0
0.0011
0.0011
0
1
0.335
0.137
0.07
0
6
33
1.51
0.343
0
0
0
0.0011
0.0011
0
3
0.343
0.147
0.06
0
***
Record
40
0
YEAR
10
YEAR
10
YEAR
10
1
1
1
­­­­­
7
YEAR
PRCP
TCUM
0
0
RUNF
TCUM
0
0
INFL
TCUM
1
1
ESLS
TCUM
0
0
1.0E3
RFLX
TCUM
0
0
1.0E5
EFLX
TCUM
0
0
1.0E5
RZFX
TCUM
0
0
1.0E5
15
Florida
Turf
­
Single
Application
FL
Turf
8/
09/
2001
Osceola
County;
Representation
of
the
Lake
Kissimmee/
Indian
River
Region;
MLRA
156A;
Metfile:
W12834.
dvf
[
Daytona
Beach]
(
old:
Met156A.
met)
***
Record
3:
0.78
0
0
25
1
3
***
Record
6
­­
ERFLAG
4
***
Record
7:
0.04
0.303
1
172.8
4
2
600
***
Record
8
1
***
Record
9
1
0.1
10
100
3
74
74
74
0
5
***
Record
9a­
d
1
25
0101
1601
0102
1602
0103
1603
0104
1604
0105
1605
0106
1606
0107
1507
1607
0108
.023
.026
.030
.035
.042
.050
.056
.060
.063
.068
.074
.079
.082
.125
.148
.189
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
1608
0109
1609
0110
1610
0111
1611
0112
1612
.229
.265
.294
.314
.326
.017
.018
.019
.021
.023
.023
.023
.023
.023
.023
.023
.023
.023
***
Record
10
­­
NCPDS,
the
number
of
cropping
periods
30
***
Record
11
010261
150261
151261
1
010262
150262
151262
1
010263
150263
151263
1
010264
150264
151264
1
010265
150265
151265
1
010266
150266
151266
1
010267
150267
151267
1
010268
150268
151268
1
010269
150269
151269
1
010270
150270
151270
1
010271
150271
151271
1
010272
150272
151272
1
010273
150273
151273
1
010274
150274
151274
1
010275
150275
151275
1
010276
150276
151276
1
010277
150277
151277
1
010278
150278
151278
1
010279
150279
151279
1
010280
150280
151280
1
010281
150281
151281
1
010282
150282
151282
1
010283
150283
151283
1
010284
150284
151284
1
010285
150285
151285
1
010286
150286
151286
1
010287
150287
151287
1
16
010288
150288
151288
1
010289
150289
151289
1
010290
150290
151290
1
***
Record
12
­­
PTITLE
imazaquin
­
1
applications
@
.56
kg/
ha
***
Record
13
30
1
0
0
***
Record
15
­­
PSTNAM
imazaquin
***
Record
16
010461
0
2
0.0
0.560.9360.064
010462
0
2
0.0
0.560.9360.064
010463
0
2
0.0
0.560.9360.064
010464
0
2
0.0
0.560.9360.064
010465
0
2
0.0
0.560.9360.064
010466
0
2
0.0
0.560.9360.064
010467
0
2
0.0
0.560.9360.064
010468
0
2
0.0
0.560.9360.064
010469
0
2
0.0
0.560.9360.064
010470
0
2
0.0
0.560.9360.064
010471
0
2
0.0
0.560.9360.064
010472
0
2
0.0
0.560.9360.064
010473
0
2
0.0
0.560.9360.064
010474
0
2
0.0
0.560.9360.064
010475
0
2
0.0
0.560.9360.064
010476
0
2
0.0
0.560.9360.064
010477
0
2
0.0
0.560.9360.064
010478
0
2
0.0
0.560.9360.064
010479
0
2
0.0
0.560.9360.064
010480
0
2
0.0
0.560.9360.064
010481
0
2
0.0
0.560.9360.064
010482
0
2
0.0
0.560.9360.064
010483
0
2
0.0
0.560.9360.064
010484
0
2
0.0
0.560.9360.064
010485
0
2
0.0
0.560.9360.064
010486
0
2
0.0
0.560.9360.064
010487
0
2
0.0
0.560.9360.064
010488
0
2
0.0
0.560.9360.064
010489
0
2
0.0
0.560.9360.064
010490
0
2
0.0
0.560.9360.064
***
Record
17
0
2
0
***
Record
18
0
0
0.5
***
Record
19
­­
STITLE
Adamsville
Sand;
Hydrologic
Group
C
***
Record
20
102
0
0
1
0
0
0
0
0
0
***
Record
26
0
0
0
***
Record
30
4
17.5
***
Record
33
4
17
1
2
0.37
0.47
0
0
0
0.0011
0.0011
0
0.1
0.47
0.27
7.5
0
2
10
1.44
0.086
0
0
0
0.0011
0.0011
0
0.1
0.086
0.036
0.58
0
3
10
1.44
0.086
0
0
0
0.0011
0.0011
0
0.1
0.086
0.036
0.58
0
4
80
1.58
0.03
0
0
0
0.0011
0.0011
0
5
0.03
0.023
0.116
0
***
Record
40
0
YEAR
10
YEAR
10
YEAR
10
1
1
1
­­­­­
7
YEAR
PRCP
TCUM
0
0
RUNF
TCUM
0
0
INFL
TCUM
1
1
ESLS
TCUM
0
0
1.0E3
RFLX
TCUM
0
0
1.0E5
EFLX
TCUM
0
0
1.0E5
RZFX
TCUM
0
0
1.0E5
18
Florida
Turf
­
Two
Applications
FL
Turf
8/
09/
2001
Osceola
County;
Representation
of
the
Lake
Kissimmee/
Indian
River
Region;
MLRA
156A;
Metfile:
W12834.
dvf
[
Daytona
Beach]
(
old:
Met156A.
met)
***
Record
3:
0.78
0
0
25
1
3
***
Record
6
­­
ERFLAG
4
***
Record
7:
0.04
0.303
1
172.8
4
2
600
***
Record
8
1
***
Record
9
1
0.1
10
100
3
74
74
74
0
5
***
Record
9a­
d
1
25
0101
1601
0102
1602
0103
1603
0104
1604
0105
1605
0106
1606
0107
1507
1607
0108
.023
.026
.030
.035
.042
.050
.056
.060
.063
.068
.074
.079
.082
.125
.148
.189
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
.023
1608
0109
1609
0110
1610
0111
1611
0112
1612
.229
.265
.294
.314
.326
.017
.018
.019
.021
.023
.023
.023
.023
.023
.023
.023
.023
.023
***
Record
10
­­
NCPDS,
the
number
of
cropping
periods
30
***
Record
11
010261
150261
151261
1
010262
150262
151262
1
010263
150263
151263
1
010264
150264
151264
1
010265
150265
151265
1
010266
150266
151266
1
010267
150267
151267
1
010268
150268
151268
1
010269
150269
151269
1
010270
150270
151270
1
010271
150271
151271
1
010272
150272
151272
1
010273
150273
151273
1
010274
150274
151274
1
010275
150275
151275
1
010276
150276
151276
1
010277
150277
151277
1
010278
150278
151278
1
010279
150279
151279
1
010280
150280
151280
1
010281
150281
151281
1
010282
150282
151282
1
010283
150283
151283
1
010284
150284
151284
1
010285
150285
151285
1
010286
150286
151286
1
010287
150287
151287
1
010288
150288
151288
1
19
010289
150289
151289
1
010290
150290
151290
1
***
Record
12
­­
PTITLE
imazaquin
­
2
applications
@
.56
kg/
ha
***
Record
13
60
1
0
0
***
Record
15
­­
PSTNAM
imazaquin
***
Record
16
010461
0
2
0.0
0.560.9360.064
290461
0
2
0.0
0.560.9360.064
010462
0
2
0.0
0.560.9360.064
290462
0
2
0.0
0.560.9360.064
010463
0
2
0.0
0.560.9360.064
290463
0
2
0.0
0.560.9360.064
010464
0
2
0.0
0.560.9360.064
290464
0
2
0.0
0.560.9360.064
010465
0
2
0.0
0.560.9360.064
290465
0
2
0.0
0.560.9360.064
010466
0
2
0.0
0.560.9360.064
290466
0
2
0.0
0.560.9360.064
010467
0
2
0.0
0.560.9360.064
290467
0
2
0.0
0.560.9360.064
010468
0
2
0.0
0.560.9360.064
290468
0
2
0.0
0.560.9360.064
010469
0
2
0.0
0.560.9360.064
290469
0
2
0.0
0.560.9360.064
010470
0
2
0.0
0.560.9360.064
290470
0
2
0.0
0.560.9360.064
010471
0
2
0.0
0.560.9360.064
290471
0
2
0.0
0.560.9360.064
010472
0
2
0.0
0.560.9360.064
290472
0
2
0.0
0.560.9360.064
010473
0
2
0.0
0.560.9360.064
290473
0
2
0.0
0.560.9360.064
010474
0
2
0.0
0.560.9360.064
290474
0
2
0.0
0.560.9360.064
010475
0
2
0.0
0.560.9360.064
290475
0
2
0.0
0.560.9360.064
010476
0
2
0.0
0.560.9360.064
290476
0
2
0.0
0.560.9360.064
010477
0
2
0.0
0.560.9360.064
290477
0
2
0.0
0.560.9360.064
010478
0
2
0.0
0.560.9360.064
290478
0
2
0.0
0.560.9360.064
010479
0
2
0.0
0.560.9360.064
290479
0
2
0.0
0.560.9360.064
010480
0
2
0.0
0.560.9360.064
290480
0
2
0.0
0.560.9360.064
010481
0
2
0.0
0.560.9360.064
290481
0
2
0.0
0.560.9360.064
010482
0
2
0.0
0.560.9360.064
290482
0
2
0.0
0.560.9360.064
010483
0
2
0.0
0.560.9360.064
20
290483
0
2
0.0
0.560.9360.064
010484
0
2
0.0
0.560.9360.064
290484
0
2
0.0
0.560.9360.064
010485
0
2
0.0
0.560.9360.064
290485
0
2
0.0
0.560.9360.064
010486
0
2
0.0
0.560.9360.064
290486
0
2
0.0
0.560.9360.064
010487
0
2
0.0
0.560.9360.064
290487
0
2
0.0
0.560.9360.064
010488
0
2
0.0
0.560.9360.064
290488
0
2
0.0
0.560.9360.064
010489
0
2
0.0
0.560.9360.064
290489
0
2
0.0
0.560.9360.064
010490
0
2
0.0
0.560.9360.064
290490
0
2
0.0
0.560.9360.064
***
Record
17
0
2
0
***
Record
18
0
0
0.5
***
Record
19
­­
STITLE
Adamsville
Sand;
Hydrologic
Group
C
***
Record
20
102
0
0
1
0
0
0
0
0
0
***
Record
26
0
0
0
***
Record
30
4
17.5
***
Record
33
4
1
2
0.37
0.47
0
0
0
0.0011
0.0011
0
0.1
0.47
0.27
7.5
0
2
10
1.44
0.086
0
0
0
0.0011
0.0011
0
0.1
0.086
0.036
0.58
0
3
10
1.44
0.086
0
0
0
0.0011
0.0011
0
0.1
0.086
0.036
0.58
0
4
80
1.58
0.03
0
0
0
0.0011
0.0011
0
5
0.03
0.023
0.116
0
***
Record
40
0
YEAR
10
YEAR
10
YEAR
10
1
1
1
­­­­­
7
YEAR
PRCP
TCUM
0
0
RUNF
TCUM
0
0
INFL
TCUM
1
1
ESLS
TCUM
0
0
1.0E3
RFLX
TCUM
0
0
1.0E5
EFLX
TCUM
0
0
1.0E5
RZFX
TCUM
0
0
1.0E5
21
Oregon
Ornamentals
ORXmastree;
11/
8/
2001
"
Benton
Co.
OR
MLRA
A2;
Metfile:
W24232.
dvf
(
old:
Met2.
met),"
***
Record
3:
0.73
0.16
0
17
1
2
***
Record
6
­­
ERFLAG
4
***
Record
7:
0.37
0.69
1
172.8
2
4
600
***
Record
8
1
***
Record
9
1
0.25
120
40
2
80
72
77
0
250
***
Record
9a­
d
1
24
0101
1601
0102
1602
0103
1603
0104
1604
0105
1605
0106
1606
0107
1607
0108
1608
.009
.010
.015
.016
.023
.029
.034
.038
.041
.039
.038
.034
.029
.024
.021
.021
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
.040
0109
1609
0110
1610
0111
1611
0112
1612
.023
.024
.027
.029
.006
.007
.007
.008
.040
.040
.040
.040
.040
.040
.040
.040
***
Record
10
­­
NCPDS,
the
number
of
cropping
periods
30
***
Record
11
150461
150861
301061
1
150462
150862
301062
1
150463
150863
301063
1
150464
150864
301064
1
150465
150865
301065
1
150466
150866
301066
1
150467
150867
301067
1
150468
150868
301068
1
150469
150869
301069
1
150470
150870
301070
1
150471
150871
301071
1
150472
150872
301072
1
150473
150873
301073
1
150474
150874
301074
1
150475
150875
301075
1
150476
150876
301076
1
150477
150877
301077
1
150478
150878
301078
1
150479
150879
301079
1
150480
150880
301080
1
150481
150881
301081
1
150482
150882
301082
1
150483
150883
301083
1
150484
150884
301084
1
150485
150885
301085
1
150486
150886
301086
1
150487
150887
301087
1
150488
150888
301088
1
22
150489
150889
301089
1
150490
150890
301090
1
***
Record
12
­­
PTITLE
imazaquin
­
1
applications
@
.56
kg/
ha
***
Record
13
30
1
0
0
***
Record
15
­­
PSTNAM
imazaquin
***
Record
16
010461
0
2
0.0
0.560.936
0.64
010462
0
2
0.0
0.560.936
0.64
010463
0
2
0.0
0.560.936
0.64
010464
0
2
0.0
0.560.936
0.64
010465
0
2
0.0
0.560.936
0.64
010466
0
2
0.0
0.560.936
0.64
010467
0
2
0.0
0.560.936
0.64
010468
0
2
0.0
0.560.936
0.64
010469
0
2
0.0
0.560.936
0.64
010470
0
2
0.0
0.560.936
0.64
010471
0
2
0.0
0.560.936
0.64
010472
0
2
0.0
0.560.936
0.64
010473
0
2
0.0
0.560.936
0.64
010474
0
2
0.0
0.560.936
0.64
010475
0
2
0.0
0.560.936
0.64
010476
0
2
0.0
0.560.936
0.64
010477
0
2
0.0
0.560.936
0.64
010478
0
2
0.0
0.560.936
0.64
010479
0
2
0.0
0.560.936
0.64
010480
0
2
0.0
0.560.936
0.64
010481
0
2
0.0
0.560.936
0.64
010482
0
2
0.0
0.560.936
0.64
010483
0
2
0.0
0.560.936
0.64
010484
0
2
0.0
0.560.936
0.64
010485
0
2
0.0
0.560.936
0.64
010486
0
2
0.0
0.560.936
0.64
010487
0
2
0.0
0.560.936
0.64
010488
0
2
0.0
0.560.936
0.64
010489
0
2
0.0
0.560.936
0.64
010490
0
2
0.0
0.560.936
0.64
***
Record
17
0
2
0
***
Record
18
0
0
0.5
***
Record
19
­­
STITLE
Pilchuck
***
Record
20
150
0
0
1
0
0
0
0
0
0
***
Record
26
0
0
0
***
Record
30
4
17.5
***
Record
33
4
1
10
1.55
0.123
0
0
0
23
0.0011
0.0011
0
0.1
0.123
0.033
1.16
0
2
40
1.7
0.123
0
0
0
0.0011
0.0011
0
2
0.123
0.033
1.16
0
3
50
1.8
0.069
0
0
0
0.0011
0.0011
0
5
0.069
0.019
0.174
0
4
50
1.8
0.046
0
0
0
0.0011
0.0011
0
5
0.046
0.016
0.116
0
***
Record
40
0
YEAR
10
YEAR
10
YEAR
10
1
1
1
­­­­­
7
YEAR
PRCP
TCUM
0
0
RUNF
TCUM
0
0
INFL
TCUM
1
1
ESLS
TCUM
0
0
1.0E3
RFLX
TCUM
0
0
1.0E5
EFLX
TCUM
0
0
1.0E5
RZFX
TCUM
0
0
1.0E5
24
Appendix
B:
PRZM/
EXAMS
Output
Files
25
Mississippi
Soybeans
stored
as
soy84.
out
Chemical:
imazaquin
PRZM
environme
nt:
MSsoybea
nC.
txt
modified
Satday,
12
October
2002
at
17:
07:
44
EXAMS
environme
nt:
ir298.
exv
modified
Thuday,
29
August
2002
at
15:
34:
12
Metfile:
w13893.
d
vf
modified
Wedday,
3
July
2002
at
09:
06:
20
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
2.959
2.882
2.617
2.11
1.791
0.6197
1962
1.016
0.9887
0.8799
0.7664
0.6705
0.2533
1963
0.939
0.9175
0.85
0.7437
0.6413
0.2298
1964
1.296
1.262
1.149
0.9193
0.7794
0.2717
1965
0.8302
0.8079
0.7217
0.5702
0.4833
0.172
1966
0.951
0.9337
0.8432
0.731
0.6283
0.2226
1967
0.9797
0.9549
0.8895
0.7317
0.6224
0.2209
1968
1.188
1.157
1.04
0.8389
0.7131
0.2499
1969
3.631
3.534
3.294
2.605
2.198
0.7607
1970
1.662
1.618
1.474
1.173
1.012
0.3721
1971
1.344
1.308
1.17
0.9477
0.8271
0.3016
1972
1.145
1.114
1.017
0.8501
0.7498
0.2744
1973
1.158
1.128
1.02
0.8396
0.7191
0.2565
1974
2.934
2.856
2.604
2.084
1.766
0.615
1975
0.8475
0.8252
0.7559
0.6261
0.533
0.1995
1976
0.852
0.8293
0.7953
0.6786
0.5814
0.205
1977
1.517
1.477
1.318
1.068
0.9276
0.3311
1978
1.217
1.184
1.076
0.8706
0.7378
0.2606
1979
10.69
10.41
9.416
7.486
6.33
2.176
1980
6.199
6.034
5.486
4.345
3.668
1.293
1981
1.055
1.027
0.92
0.789
0.6808
0.2669
1982
2.818
2.779
2.531
2.006
1.696
0.5974
1983
4.52
4.404
3.996
3.173
2.684
0.9344
1984
0.9588
0.936
0.8503
0.7522
0.6519
0.2509
1985
4.125
4.014
3.594
2.827
2.383
0.8411
1986
0.8945
0.8749
0.8219
0.6789
0.5786
0.2221
1987
2.491
2.424
2.163
1.698
1.434
0.4989
1988
1.439
1.4
1.274
1.035
0.8773
0.3116
1989
0.8318
0.8097
0.7245
0.5724
0.4851
0.1741
1990
1.43
1.405
1.303
1.05
0.9054
0.3188
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
26
0.032258
10.69
10.41
9.416
7.486
6.33
2.176
0.064516
6.199
6.034
5.486
4.345
3.668
1.293
0.096774
4.52
4.404
3.996
3.173
2.684
0.9344
0.129032
4.125
4.014
3.594
2.827
2.383
0.8411
0.16129
3.631
3.534
3.294
2.605
2.198
0.7607
0.193548
2.959
2.882
2.617
2.11
1.791
0.6197
0.225806
2.934
2.856
2.604
2.084
1.766
0.615
0.258065
2.818
2.779
2.531
2.006
1.696
0.5974
0.290323
2.491
2.424
2.163
1.698
1.434
0.4989
0.322581
1.662
1.618
1.474
1.173
1.012
0.3721
0.354839
1.517
1.477
1.318
1.068
0.9276
0.3311
0.387097
1.439
1.405
1.303
1.05
0.9054
0.3188
0.419355
1.43
1.4
1.274
1.035
0.8773
0.3116
0.451613
1.344
1.308
1.17
0.9477
0.8271
0.3016
0.483871
1.296
1.262
1.149
0.9193
0.7794
0.2744
0.516129
1.217
1.184
1.076
0.8706
0.7498
0.2717
0.548387
1.188
1.157
1.04
0.8501
0.7378
0.2669
0.580645
1.158
1.128
1.02
0.8396
0.7191
0.2606
0.612903
1.145
1.114
1.017
0.8389
0.7131
0.2565
0.645161
1.055
1.027
0.92
0.789
0.6808
0.2533
0.677419
1.016
0.9887
0.8895
0.7664
0.6705
0.2509
0.709677
0.9797
0.9549
0.8799
0.7522
0.6519
0.2499
0.741935
0.9588
0.936
0.8503
0.7437
0.6413
0.2298
0.774194
0.951
0.9337
0.85
0.7317
0.6283
0.2226
0.806452
0.939
0.9175
0.8432
0.731
0.6224
0.2221
0.83871
0.8945
0.8749
0.8219
0.6789
0.5814
0.2209
0.870968
0.852
0.8293
0.7953
0.6786
0.5786
0.205
0.903226
0.8475
0.8252
0.7559
0.6261
0.533
0.1995
0.935484
0.8318
0.8097
0.7245
0.5724
0.4851
0.1741
0.967742
0.8302
0.8079
0.7217
0.5702
0.4833
0.172
0.1
4.4805
4.365
3.9558
3.1384
2.6539
0.92507
Average
of
yearly
averages:
0.45672
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
27
Florida
Turf
­
Single
Application
stored
as
tf1apr1.
out
Chemical:
imazaquin
PRZM
environme
nt:
FLturfC.
txt
modified
Monday,
16
June
2003
at
14:
48:
06
EXAMS
environme
nt:
ir298.
exv
modified
Thuday,
29
August
2002
at
15:
34:
12
Metfile:
w12834.
d
vf
modified
Wedday,
3
July
2002
at
09:
04:
28
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
1.308
1.286
1.242
1.132
1.047
0.4784
1962
1.681
1.661
1.567
1.37
1.242
0.7496
1963
1.906
1.888
1.781
1.601
1.521
0.8549
1964
10.07
9.923
9.393
8.169
7.372
3.328
1965
3.136
3.097
2.995
2.635
2.389
1.603
1966
10.95
10.78
10.12
8.935
8.149
3.811
1967
4.556
4.492
4.253
3.735
3.388
1.978
1968
1.854
1.826
1.716
1.523
1.534
0.9614
1969
3.281
3.233
3.1
2.738
2.484
1.276
1970
3.964
3.906
3.672
3.218
2.936
1.45
1971
9.209
9.07
8.51
7.433
6.736
3.108
1972
2.021
1.991
1.871
1.705
1.608
0.9969
1973
3.809
3.751
3.569
3.117
2.82
1.324
1974
1.596
1.571
1.472
1.279
1.189
0.6491
1975
5.13
5.052
4.768
4.151
3.755
1.727
1976
21.53
21.2
19.85
17.29
15.66
7.042
1977
3.104
3.063
2.897
2.556
2.462
1.792
1978
13.4
13.19
12.33
10.66
9.622
4.327
1979
2.379
2.344
2.202
2.087
1.923
1.241
1980
3.515
3.474
3.268
2.915
2.665
1.255
1981
2.83
2.786
2.607
2.271
2.076
1.143
1982
20.18
19.89
18.7
16.25
14.66
6.534
1983
6.844
6.739
6.408
5.58
5.041
2.785
1984
15.37
15.16
14.23
12.36
11.15
5.055
1985
4.021
3.961
3.719
3.227
2.93
1.711
1986
1.623
1.596
1.491
1.286
1.159
0.6214
1987
1.728
1.702
1.596
1.387
1.346
0.6908
1988
1.47
1.447
1.357
1.253
1.162
0.5844
1989
2.861
2.815
2.647
2.288
2.058
1.009
1990
1.547
1.523
1.426
1.235
1.114
0.5709
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.032258
21.53
21.2
19.85
17.29
15.66
7.042
28
0.064516
20.18
19.89
18.7
16.25
14.66
6.534
0.096774
15.37
15.16
14.23
12.36
11.15
5.055
0.129032
13.4
13.19
12.33
10.66
9.622
4.327
0.16129
10.95
10.78
10.12
8.935
8.149
3.811
0.193548
10.07
9.923
9.393
8.169
7.372
3.328
0.225806
9.209
9.07
8.51
7.433
6.736
3.108
0.258065
6.844
6.739
6.408
5.58
5.041
2.785
0.290323
5.13
5.052
4.768
4.151
3.755
1.978
0.322581
4.556
4.492
4.253
3.735
3.388
1.792
0.354839
4.021
3.961
3.719
3.227
2.936
1.727
0.387097
3.964
3.906
3.672
3.218
2.93
1.711
0.419355
3.809
3.751
3.569
3.117
2.82
1.603
0.451613
3.515
3.474
3.268
2.915
2.665
1.45
0.483871
3.281
3.233
3.1
2.738
2.484
1.324
0.516129
3.136
3.097
2.995
2.635
2.462
1.276
0.548387
3.104
3.063
2.897
2.556
2.389
1.255
0.580645
2.861
2.815
2.647
2.288
2.076
1.241
0.612903
2.83
2.786
2.607
2.271
2.058
1.143
0.645161
2.379
2.344
2.202
2.087
1.923
1.009
0.677419
2.021
1.991
1.871
1.705
1.608
0.9969
0.709677
1.906
1.888
1.781
1.601
1.534
0.9614
0.741935
1.854
1.826
1.716
1.523
1.521
0.8549
0.774194
1.728
1.702
1.596
1.387
1.346
0.7496
0.806452
1.681
1.661
1.567
1.37
1.242
0.6908
0.83871
1.623
1.596
1.491
1.286
1.189
0.6491
0.870968
1.596
1.571
1.472
1.279
1.162
0.6214
0.903226
1.547
1.523
1.426
1.253
1.159
0.5844
0.935484
1.47
1.447
1.357
1.235
1.114
0.5709
0.967742
1.308
1.286
1.242
1.132
1.047
0.4784
0.1
15.173
14.963
14.04
12.19
10.9972
4.9822
Average
of
yearly
averages:
2.021893
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
29
Florida
Turf
­
Two
Applications
stored
as
tf2apr1.
out
Chemical:
imazaquin
PRZM
environme
nt:
FLturfC.
txt
modified
Monday,
16
June
2003
at
14:
48:
06
EXAMS
environme
nt:
ir298.
exv
modified
Thuday,
29
August
2002
at
15:
34:
12
Metfile:
w12834.
d
vf
modified
Wedday,
3
July
2002
at
09:
04:
28
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
3.181
3.134
2.941
2.607
2.409
1.15
1962
4.554
4.501
4.247
3.712
3.365
1.827
1963
5.682
5.623
5.312
4.64
4.336
2.303
1964
14.97
14.74
13.83
12.12
11.01
5.097
1965
9.097
8.992
8.664
7.632
6.919
3.777
1966
14.16
13.96
13.17
11.73
11.33
5.886
1967
9.091
8.963
8.483
7.448
6.756
3.715
1968
3.772
3.733
3.586
3.239
3.119
1.969
1969
6.881
6.779
6.502
5.741
5.207
2.592
1970
4.969
4.893
4.592
4.429
4.269
2.353
1971
10.71
10.54
9.884
9.053
8.788
4.429
1972
3.647
3.596
3.39
3.133
2.897
1.819
1973
4.695
4.624
4.34
3.955
3.729
1.88
1974
2.702
2.661
2.501
2.302
2.137
1.207
1975
5.936
5.847
5.491
5.053
4.677
2.243
1976
21.65
21.32
19.96
19.07
17.69
8.207
1977
5.405
5.333
5.024
4.365
4.104
2.798
1978
13.8
13.58
13.16
12.32
11.82
5.746
1979
6.519
6.427
6.032
5.243
4.768
2.812
1980
7.208
7.098
6.7
5.854
5.341
2.8
1981
6.138
6.043
5.654
4.929
4.511
2.429
1982
20.54
20.24
19.03
17.63
16.46
7.754
1983
15.09
14.91
14.09
12.28
11.07
6.147
1984
22.18
21.84
20.49
17.8
16.45
9.088
1985
5.813
5.726
5.366
4.931
4.564
2.926
1986
2.771
2.727
2.554
2.217
2.027
1.169
1987
3.838
3.779
3.542
3.078
2.826
1.419
1988
2.989
2.955
2.78
2.47
2.254
1.205
1989
7.922
7.795
7.324
6.33
5.694
2.603
1990
2.892
2.848
2.67
2.32
2.137
1.255
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.032258
22.18
21.84
20.49
19.07
17.69
9.088
30
0.064516
21.65
21.32
19.96
17.8
16.46
8.207
0.096774
20.54
20.24
19.03
17.63
16.45
7.754
0.129032
15.09
14.91
14.09
12.32
11.82
6.147
0.16129
14.97
14.74
13.83
12.28
11.33
5.886
0.193548
14.16
13.96
13.17
12.12
11.07
5.746
0.225806
13.8
13.58
13.16
11.73
11.01
5.097
0.258065
10.71
10.54
9.884
9.053
8.788
4.429
0.290323
9.097
8.992
8.664
7.632
6.919
3.777
0.322581
9.091
8.963
8.483
7.448
6.756
3.715
0.354839
7.922
7.795
7.324
6.33
5.694
2.926
0.387097
7.208
7.098
6.7
5.854
5.341
2.812
0.419355
6.881
6.779
6.502
5.741
5.207
2.8
0.451613
6.519
6.427
6.032
5.243
4.768
2.798
0.483871
6.138
6.043
5.654
5.053
4.677
2.603
0.516129
5.936
5.847
5.491
4.931
4.564
2.592
0.548387
5.813
5.726
5.366
4.929
4.511
2.429
0.580645
5.682
5.623
5.312
4.64
4.336
2.353
0.612903
5.405
5.333
5.024
4.429
4.269
2.303
0.645161
4.969
4.893
4.592
4.365
4.104
2.243
0.677419
4.695
4.624
4.34
3.955
3.729
1.969
0.709677
4.554
4.501
4.247
3.712
3.365
1.88
0.741935
3.838
3.779
3.586
3.239
3.119
1.827
0.774194
3.772
3.733
3.542
3.133
2.897
1.819
0.806452
3.647
3.596
3.39
3.078
2.826
1.419
0.83871
3.181
3.134
2.941
2.607
2.409
1.255
0.870968
2.989
2.955
2.78
2.47
2.254
1.207
0.903226
2.892
2.848
2.67
2.32
2.137
1.205
0.935484
2.771
2.727
2.554
2.302
2.137
1.169
0.967742
2.702
2.661
2.501
2.217
2.027
1.15
0.1
19.995
19.707
18.536
17.099
15.987
7.5933
Average
of
yearly
averages:
3.3535
31
Oregon
Christmas
Tree
stored
as
ORxmas.
out
Chemical:
imazaquin
PRZM
environme
nt:
ORXmasT
reeC.
txt
modified
Satday,
12
October
2002
at
17:
23:
10
EXAMS
environme
nt:
ir298.
exv
modified
Thuday,
29
August
2002
at
15:
34:
12
Metfile:
w24232.
d
vf
modified
Wedday,
3
July
2002
at
09:
06:
10
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
13.08
12.94
12.51
11.61
10.96
5.817
1962
16.16
16.03
15.5
14.4
13.62
8.21
1963
17.02
16.89
16.46
15.32
14.47
8.999
1964
17.33
17.19
16.62
15.41
14.56
9.113
1965
17.32
17.18
16.63
15.43
14.54
9.005
1966
17.28
17.13
16.53
15.25
14.35
8.88
1967
17.23
17.09
16.53
15.3
14.41
8.796
1968
17.02
16.89
16.31
15.11
14.26
8.828
1969
17.3
17.16
16.62
15.4
14.52
9.035
1970
17.25
17.12
16.57
15.36
14.47
8.913
1971
17.41
17.28
16.98
15.9
15.06
9.317
1972
17.51
17.37
16.82
15.59
14.68
9.079
1973
17.24
17.1
16.51
15.24
14.36
8.892
1974
17.25
17.12
16.58
15.41
14.55
8.96
1975
17.19
17.05
16.49
15.27
14.39
8.901
1976
17.16
17.03
16.47
15.25
14.38
8.887
1977
17.07
16.93
16.34
15.14
14.29
8.836
1978
17.28
17.15
16.61
15.42
14.55
9.036
1979
17.52
17.38
16.83
15.61
14.69
9.094
1980
17.23
17.09
16.66
15.46
14.63
9.037
1981
17.22
17.09
16.55
15.38
14.54
9.001
1982
17.22
17.08
16.49
15.23
14.33
8.88
1983
17.22
17.07
16.48
15.22
14.35
8.955
1984
17.27
17.14
16.61
15.44
14.59
9.024
1985
17.2
17.06
16.48
15.26
14.39
8.841
1986
17.05
16.91
16.35
15.17
14.3
8.807
1987
17.12
16.98
16.39
15.14
14.24
8.717
1988
16.98
16.85
16.31
15.16
14.32
8.761
1989
17.17
17.03
16.44
15.21
14.34
8.883
1990
17.21
17.07
16.5
15.31
14.49
9.008
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
32
0.032258
17.52
17.38
16.98
15.9
15.06
9.317
0.064516
17.51
17.37
16.83
15.61
14.69
9.113
0.096774
17.41
17.28
16.82
15.59
14.68
9.094
0.129032
17.33
17.19
16.66
15.46
14.63
9.079
0.16129
17.32
17.18
16.63
15.44
14.59
9.037
0.193548
17.3
17.16
16.62
15.43
14.56
9.036
0.225806
17.28
17.15
16.62
15.42
14.55
9.035
0.258065
17.28
17.14
16.61
15.41
14.55
9.024
0.290323
17.27
17.13
16.61
15.41
14.54
9.008
0.322581
17.25
17.12
16.58
15.4
14.54
9.005
0.354839
17.25
17.12
16.57
15.38
14.52
9.001
0.387097
17.24
17.1
16.55
15.36
14.49
8.999
0.419355
17.23
17.09
16.53
15.32
14.47
8.96
0.451613
17.23
17.09
16.53
15.31
14.47
8.955
0.483871
17.22
17.09
16.51
15.3
14.41
8.913
0.516129
17.22
17.08
16.5
15.27
14.39
8.901
0.548387
17.22
17.07
16.49
15.26
14.39
8.892
0.580645
17.21
17.07
16.49
15.25
14.38
8.887
0.612903
17.2
17.06
16.48
15.25
14.36
8.883
0.645161
17.19
17.05
16.48
15.24
14.35
8.88
0.677419
17.17
17.03
16.47
15.23
14.35
8.88
0.709677
17.16
17.03
16.46
15.22
14.34
8.841
0.741935
17.12
16.98
16.44
15.21
14.33
8.836
0.774194
17.07
16.93
16.39
15.17
14.32
8.828
0.806452
17.05
16.91
16.35
15.16
14.3
8.807
0.83871
17.02
16.89
16.34
15.14
14.29
8.796
0.870968
17.02
16.89
16.31
15.14
14.26
8.761
0.903226
16.98
16.85
16.31
15.11
14.24
8.717
0.935484
16.16
16.03
15.5
14.4
13.62
8.21
0.967742
13.08
12.94
12.51
11.61
10.96
5.817
0.1
17.402
17.271
16.804
15.577
14.675
9.0925
Average
of
yearly
averages:
8.817067
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
33
Appendix
C:
SCIGROW
Input/
Output
Modeling
File
SCIGROW
VERSION
2.3
ENVIRONMENTAL
FATE
AND
EFFECTS
DIVISION
OFFICE
OF
PESTICIDE
PROGRAMS
U.
S.
ENVIRONMENTAL
PROTECTION
AGENCY
SCREENING
MODEL
FOR
AQUATIC
PESTICIDE
EXPOSURE
SOYBEANS
SciGrow
version
2.3
chemical:
Imazaquin
time
is
6/
8/
2005
16:
58:
31
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Application
Number
of
Total
Use
Koc
Soil
Aerobic
rate
(
lb/
acre)
applications
(
lb/
acre/
yr)
(
ml/
g)
metabolism
(
days)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
0.123
1.0
0.123
1.75E+
01
210.0
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
groundwater
screening
cond
(
ppb)
=
3.83E+
00
************************************************************************

TURF
/
ORNAMENTALS
SciGrow
version
2.3
chemical:
Imazaquin
time
is
6/
8/
2005
16:
58:
17
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Application
Number
of
Total
Use
Koc
Soil
Aerobic
rate
(
lb/
acre)
applications
(
lb/
acre/
yr)
(
ml/
g)
metabolism
(
days)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
0.500
1.0
0.500
1.75E+
01
210.0
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
groundwater
screening
cond
(
ppb)
=
1.56E+
01
************************************************************************

SciGrow
version
2.3
chemical:
Imazaquin
time
is
6/
8/
2005
16:
58:
23
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Application
Number
of
Total
Use
Koc
Soil
Aerobic
rate
(
lb/
acre)
applications
(
lb/
acre/
yr)
(
ml/
g)
metabolism
(
days)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
0.500
2.0
1.000
1.75E+
01
210.0
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
groundwater
screening
cond
(
ppb)
=
3.11E+
01
************************************************************************
34
References
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W.
A.,
E.
T.
Furlong,
and
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R.
Burkhardt.
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Concentration
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and
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Herbicides,
Other
Pesticides,
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­
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oncentration
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ater:
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htm
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the
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U.
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gov/
oppfead1/
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pdf
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G.
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250.
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http://
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pdf
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