Document ID: EPA-HQ-OPP-2005-0293-0003
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2005-12-28T05:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON
D.
C.,
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
PC
Code
109702
DP
Barcode
D289428
MEMORANDUM
DATE:
May
02,
2005
SUBJECT:
Tier
II
Estimated
Environmental
Concentrations
of
Cypermethrin
for
the
Use
in
the
Human
Health
Risk
Assessment.

TO:
Cathryn
O'Connell,
Chemical
Review
Manager
Margaret
Rice,
Branch
Chief
Reregistration
Branch
II
Special
Review
and
Reregistration
Division
(
7508C)

AND:
William
Donovan,
Risk
Assessor
Reregistration
Branch
III
Health
Effects
Division
(
7509C)

FROM:
José
Luis
Meléndez,
Chemist
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
THROUGH:
Mah
T.
Shamim,
Ph.
D.,
Chief
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
(
7507C)

This
memo
presents
the
Estimated
Surface
Drinking
Water
Concentrations
and
Estimated
Ground
Water
Concentrations
(
EDWCs)
for
CYPERMETHRIN,
calculated
using
the
Tier
2
aquatic
model
PRZM/
EXAMS
and
the
Tier
1
aquatic
model
SCI­
GROW,
respectively,
for
use
in
the
human
health
risk
assessment.

The
Estimated
Drinking
Water
Concentrations
(
EDWCs)
for
cypermethrin
were
calculated
based
on
a
maximum
application
rate
of
0.6
lb
a.
i./
A/
season.
The
acute
drinking
water
concentration
in
surface
water
is
1.04
ppb
of
cypermethrin.
The
cancer/
chronic
drinking
water
concentration
is
0.013
ppb,
using
the
NC
cotton
scenario.
These
values
represent
the
mean
value
over
a
30­
year
period.
Various
other
scenarios
were
also
explored
(
CA,
MS
and
TX
cotton,
CA
onion
and
CA
lettuce),
but
they
consistently
yielded
lower
EDWCs.
The
SCI­
GROW
generated
EDWC
(
for
cotton
or
lettuce,
highest
application
rate)
is
0.0036
ppb
of
cypermethrin,
which
is
recommended
for
use,
both
for
acute
and
chronic
exposures.
­
2­
1.
Introduction
Cypermethrin
is
a
pyrethroid
insecticide
with
both
agricultural
and
non
agricultural
applications.
For
agricultural
uses
in
the
United
States,
cypermethrin
is
predominantly
used
to
control
pests
on
cotton,
lettuce,
pecans
and
onions,
with
the
predominant
use
being
cotton
(
80%
of
the
total
agricultural
usage).
It
may
be
used
alone
or
in
conjunction
with
organophosphate
pesticides
to
control
pests
such
as
budworm
and
bollworm
populations
on
cotton
and
worms
and
aphids
on
lettuce.
Application
rates
and
the
timing
of
these
applications
vary
by
crop
type.
Non
agricultural
uses
of
cypermethrin
include
pest
management
inside
greenhouses,
food
processing,
storage,
and
dairy
facilities
(
non
contact
food
uses
only),
wood
treatment
applications,
animal
kennels,
commercial
storage
facilities,
automobile
and
taxi
services,
and
applications
to
drainage
systems.

Cypermethrin
is
expected
to
have
little
mobility
in
soil
surfaces
and
leaching
into
groundwater
is
not
expected
to
be
an
important
environmental
fate
process
(
mean
Koc=
141,700).
Volatilization
is
not
expected
to
be
an
important
transport
process
since
cypermethrin
has
a
relatively
low
vapor
pressure
and
Henry's
Law
constant
(
2.5x10­
9
mm
Hg
and
3.4x10­
7
Atm­
m3/
mole,
respectively).
Cypermethrin
is
moderately
persistent
in
the
environment
and
degrades
through
a
combination
of
biotic
and
abiotic
mechanisms.
Cypermethrin
hydrolyzes
slowly
at
acidic
and
neutral
pH,
but
degrades
in
a
matter
of
days
under
alkaline
conditions.
Cypermethrin
is
more
light
stable
than
the
first
or
second
generation
pyrethroids
like
allethrin
and
resmethrin,
but
still
undergoes
photolysis
in
water,
with
half­
lives
of
about
a
month
or
more
in
distilled
water
(
half­
life
36.2
days).
The
rate
of
photolysis
appears
to
be
enhanced
in
natural
waters
(
which
contain
photosensitizing
agents
like
humic
and
fulvic
acids),
where
the
accelerated
degradation
results
in
half­
lives
of
a
few
days
or
less.
Under
both
aerobic
and
anaerobic
soil
metabolism
conditions,
cypermethrin
biodegrades
relatively
slowly,
with
half­
lives
on
the
order
of
about
2
months,
but
in
aquatic
metabolism
conditions,
it
biodegrades
more
rapidly,
with
half­
lives
on
the
order
of
one
to
two
weeks.
The
primary
degradation
products
of
cypermethrin
are
cis­
and
trans­
DCVA
[(
±
)
cis­
or
trans­
3­(
2,2­
dichloroethenyl)­
2,2­
dimethylcyclopropane
carboxylic
acid],
3­
phenoxybenzaldehyde,
and
3­
PBA
[
3­
phenoxybenzoic
acid].
They
result
from
cleavage
of
the
ester
linkage
of
the
cypermethrin
molecule.

Estimated
Drinking
Water
Concentrations
(
EDWC)
were
calculated
for
groundwater
and
surface
water
utilizing
the
tier
1
aquatic
model
SCI­
GROW,
and
tier
2
aquatic
model
PRZM/
EXAMS,
respectively.

2.
SCI­
GROW
The
tier
1
aquatic
model
SCI­
GROW
was
employed
to
estimate
levels
of
cypermethrin
that
may
potentially
reach
groundwater.
SCI­
GROW
is
a
screening
model
which
is
used
to
estimate
pesticide
concentrations
in
vulnerable
ground
water.
Pesticide
concentrations
estimated
by
SCIGROW
represent
conservative
or
high­
end
exposure
values
because
the
model
is
based
on
ground­
water
monitoring
studies
which
were
conducted
by
applying
pesticides
at
maximum
allowed
rates
and
frequency,
to
vulnerable
sites
(
i.
e.,
shallow
aquifers,
sandy,
permeable
soils,
and
substantial
rainfall
and/
or
irrigation
to
maximize
leaching).
In
most
cases,
the
majority
of
the
use
­
3­
areas
will
have
ground
water
that
is
less
vulnerable
to
contamination
than
the
areas
used
to
derive
the
SCI­
GROW
estimate.
The
SCI­
GROW
input
parameters
for
cypermethrin
are
shown
in
Table
1.
The
SCI­
GROW
output
file
is
shown
in
Appendix
C.

Table
1.
SCI­
GROW
Input
Parameters
and
Estimated
Environmental
Concentration
of
Cypermethrin
in
Groundwater
PARAMETER
VALUE
SOURCE
Application
rate
(
lbs
a.
i./
A)
0.1
Product
Label:
Ammo
2.5
EC
(
EPA
Reg.
No.
279­
3027),
and
Mustang
(
EPA
Reg.
No.
279­
3126)

Number
of
applications
6
Product
Label:
Ammo
2.5
EC
(
EPA
Reg.
No.
279­
3027),
and
Mustang
(
EPA
Reg.
No.
279­
3126)

Koc
20,800
MRID
42129002
and
42129003
(
lowest
value,
there
is
greater
than
three­
fold
variation
among
values)

Soil
aerobic
half­
life
(
days)
60.2
MRID
42156601
Estimated
Groundwater
concentration
(
ppb)
0.0036
Output
value
from
SCI­
GROW
For
the
SCI­
GROW
model,
if
the
K
oc
range
has
greater
than
3­
fold
variation
in
the
values,
the
lowest
value
is
employed.
It
is
also
noted
that
estimated
concentrations
of
chemicals
with
K
oc
values
greater
than
9995
mL/
g
are
beyond
the
scope
of
the
regression
data
used
in
SCI­
GROW
development.
The
maximum
application
rate
for
cypermethrin
of
0.1
lbs
a.
i./
A
for
six
applications
per
season
was
chosen.
This
maximum
seasonal
application
rate
is
representative
of
various
crops
such
as
cotton
and
lettuce,
considered
in
this
assessment.

3.
PRZM/
EXAMS
Drinking
Water
Concentrations
The
tier
2
linked
model
PRZM/
EXAMS
was
employed
to
calculate
surface
water
concentrations
(
EDWCs)
of
cypermethrin
in
an
index
reservoir,
which
is
used
for
assessment
of
vulnerable
surface
drinking
water
sources.
The
Index
Reservoir
is
intended
as
a
drop­
in
replacement
for
the
standard
pond
for
use
in
drinking
water
assessments.
It
is
used
in
a
manner
similar
to
the
standard
pond
except
that
flow
rates
are
calibrated
to
be
consistent
with
local
weather
conditions.
The
morphology
of
the
reservoir
and
its
watershed
are
designed
to
correspond
with
those
of
Shipman
City
Lake,
a
small
reservoir
in
Illinois
selected
to
represent
small
runoff­
vulnerable
drinking
water
surface
supplies
in
agricultural
areas.
It
is
noted
that
the
surface
water
concentrations
generated
from
EXAMS
were
multiplied
by
Percent
Crop
Area
(
PCA)
factors.
In
1999,
EFED
proposed
using
PCA
factors
in
pesticide
exposure
assessments
to
account
for
the
fact
that
a
watershed
of
­
4­
sufficient
size
to
supply
a
drinking
water
source
is
not
likely
to
be
devoted
entirely
to
growing
crops
(
EPA
2003a).
Generally
a
PCA
factor
of
0.87
is
employed
in
drinking
water
assessments
unless
the
assessment
is
for
a
crop
for
which
there
is
a
refined
PCA
estimate.
In
this
Drinking
Water
Assessment,
the
EDWCs
were
obtained
by
multiplication
of
the
output
concentration
of
PRZM/
EXAMS
by
0.20
for
the
cotton
scenarios
and
0.87
for
the
CA
onion
and
CA
lettuce
crop
scenarios.
The
PRZM/
EXAMS
input
parameters
are
shown
in
Tables
2
and
3.
They
were
selected
according
to
current
EFED
guidelines
for
the
selection
of
input
parameters
for
aquatic
models.
The
output
files
from
the
PRZM/
EXAMS
runs
are
provided
in
Appendix
C.

Table
2.
PRZM/
EXAMS
Input
Parameters
for
Cypermethrin
used
in
the
Drinking
Water
Assessment.

PARAMETER
VALUE
SOURCE
Maximum
Individual
Application
Rate/
Number
of
Applications
Per
Season/
Minimum
Interval
Between
Applications/
Application
Date
Refer
to
Table
3
for
details.
Crop
specific.
According
to
the
label
and,
application
date
according
to
common
agricultural
practices.

Aerobic
soil
metabolism
62
days
MRID
42156601
(
90%
C.
L.
on
the
mean,
n
=
2
observations)

Koc
141,700
MRID
42129002
and
42129003
(
mean
value,
n
=
4)

Henry's
law
constant
3.4x10­
7
atm­
m3/
mol
Laskowski
(
2002)

Aerobic
Aquatic
Metabolism
11.3
days
MRID
44876106
(
90%
C.
L.
on
the
mean,
n
=
2
observations)

Anaerobic
Aquatic
Metabolism
19.3
days
MRID
44876105
(
90%
C.
L.
on
the
mean,
n
=
2
observations)

Aqueous
photolysis
36.2
days
MRID
42395701
Hydrolysis
half­
life
(
days)
pH
5
pH
7
pH
9
stable
stable
1.90
days
MRID
42620501
Molecular
weight
416.3
g/
mole
Laskowski
(
2002)

Solubility
(
WSOL)
0.040
ppm
Laskowski
(
2002)
(
solubility
x
10)

Vapor
pressure
(
VP)
2.5x10­
9
mm
Hg
Laskowski
(
2002)

PLDKRT
(
foliage
pesticide
rate
constant)
0.13
days­
1
Willis
and
McDowell
1987
FEXTRC
(
foliar
extraction)
0.5
EFED
Model
Input
Guidance,
Version
II
(
2002)
Table
2.
PRZM/
EXAMS
Input
Parameters
for
Cypermethrin
used
in
the
Drinking
Water
Assessment.

PARAMETER
VALUE
SOURCE
­
5­
FILTRA
(
filtration
parameter;
required
if
CAM
set
to
3)
NA
­­

PLVKRT
(
pesticide
decay
rate
on
plant
foliage)
0/
day
EFED
Model
Input
Guidance,
Version
II
(
2002)

CAM
(
chemical
application
method)
2
Reflects
foliar
application
UPTKF
(
plant
uptake
factor)
0
EFED
Model
Input
Guidance,
Version
II
(
2002)

IPSCND
1
Surface
Applied
Application
efficiency
0.95
EFED
Model
Input
Guidance,
Version
II
(
2002)

spray
drift
0.16
EPA
(
2003a).
Default
used
for
Drinking
Water
Assessments
for
aerial
applications
PCA
Cotton
­
0.20
Lettuce
and
Onion
­
0.87
EPA
(
2003a).

Four
PRZM
scenarios
were
modeled
for
cotton
crop
usage
:
California,
Mississippi,
North
Carolina
and
Texas.
Each
of
these
were
modeled
using
the
same
application
rates
and
use
patterns.
The
California
scenario
is
based
on
data
from
Fresno
County
in
the
Central
Valley
region.
The
Mississippi
scenario
arises
from
Yazoo
County.
The
North
Carolina
PRZM
scenario
is
representative
of
the
Piedmont/
Coastal
Plain
region.
The
Texas
scenario
is
typically
planted
in
the
spring
with
crop
maturity
occurring
roughly
4
months
after
the
planting
date.
While
late
season
planting
can
occur
up
to
June
in
many
southern
states,
it
is
not
advisable
to
begin
planting
after
mid
May
because
of
the
steep
decline
in
yield
(
the
best
yields
usually
occur
with
early
season
planting,
optimal
soil
temperature
and
moisture
and
air
temperature).
Harvest
typically
occurs
from
September
1,
through
December.
It
is
not
advisable
to
use
pyrethroid
insecticides
on
cotton
crops
prior
to
July
1
unless
infestations
are
high
in
order
to
avoid
insect
resistence
later
in
the
season
(
Roof
2004).

The
field
used
to
represent
onion
production
in
California
is
located
in
Kern
County
in
the
San
Joaquin
Valley,
although
onion
production
areas
are
quite
extensive
(
San
Joaquin,
Coastal­
Intermediate
Region,
Imperial
Valley,
southern
and
central
coastal
regions,
the
high
desert
areas
of
Los
Angeles
County
and
the
northern
mountain
valleys).
Bulb
onions
are
planted
from
September
through
May
and
harvesting
begins
in
April
or
May
and
completed
by
September.

Only
one
validated
PRZM
scenario
currently
exists
for
lettuce
(
California).
Lettuce
is
a
year
­
6­
round
crop
in
California,
so
the
application
timing
of
cypermethrin
can
vary
(
Jackson
et.
al.
1996).

Table
3.
Crop
Usage
Patterns
for
Cypermethrin
on
Cotton,
Onions,
and
Lettuce1
Crop
or
Crop
Group
Maximum
Individual
Application
Rate
(
lb
a.
i./
A)
Number
of
Applications
per
season
Minimum
Application
Interval
(
days)
Application
Date
(
typical
agricultural
practices)

Cotton
0.1
(
0.112
kg/
ha)
6
3
July
1st
Onion
0.1
(
0.112
kg/
ha)
5
7
May
10th
Lettuce
0.1
(
0.112
kg/
ha)
6
7
August
1st
(
1).
Data
obtained
from
label
for
Ammo
2.5
EC
(
EPA
Reg.
No.
279­
3027).

EDWCs
are
summarized
in
Table
4.

Table
4.
EDWC
for
Cypermethrin
(
ppb
or
:
g/
L)
Obtained
from
PRZM/
EXAMS.

Site
and
Crop
Peak
Annual
Average
(
Cancer/
Chronic)

Californiaa
Cotton
0.12
0.003
Mississippia
Cotton
0.47
0.009
North
Carolinaa
Cotton
1.04
0.013
Texasa
Cotton
0.24
0.005
Californiab
Onion
0.45
0.013
Californiab
Lettuce
0.60
0.027
a.
PRZM/
EXAMS
EDWC
multiplied
by
0.20
(
PCA
for
cotton).
b.
PRZM/
EXAMS
EDWC
multiplied
by
0.87
(
PCA
for
other
crops).
­
7­
Appendix
A.
Background
Information
on
SCI­
GROW
and
PRZM/
EXAMS,
and
PRZM
Scenarios
BACKGROUND
INFORMATION
ON
SCI­
GROW
SCI­
GROW
V.
2.3
provides
a
groundwater
screening
exposure
value
to
be
used
in
determining
the
potential
risk
to
human
health
from
drinking
water
contaminated
with
the
pesticide.
Since
the
SCI­
GROW
concentrations
are
likely
to
be
approached
in
only
a
very
small
percentage
of
drinking
water
sources,
i.
e.,
highly
vulnerable
aquifers,
it
is
not
appropriate
to
use
SCI­
GROW
for
national
or
regional
exposure
estimates.

SCI­
GROW
estimates
likely
groundwater
concentrations
if
the
pesticide
is
used
at
the
maximum
allowable
rate
in
areas
where
groundwater
is
exceptionally
vulnerable
to
contamination.
In
most
cases,
a
large
majority
of
the
use
area
will
have
groundwater
that
is
less
vulnerable
to
contamination
than
the
areas
used
to
derive
the
SCI­
GROW
estimate.

Estimated
concentrations
of
chemicals
with
K
OC
values
greater
than
9995
ml/
g
are
beyond
the
scope
of
the
regression
data
used
in
SCI­
GROW
development.
If
there
are
concerns
for
such
chemicals,
a
higher
tier
groundwater
exposure
assessment
should
be
considered,
regardless
of
the
concentration
returned
by
SCI­
GROW.

BACKGROUND
INFORMATION
ON
PRZM/
EXAMS
The
Tier
II
aquatic
model
employs
PRZM
(
Pesticide
Root
Zone
Model;
version
3.12
Beta
compiled
May
24,
2001)
and
EXAMS
(
Exposure
Analysis
Modeling
System;
version
2.98.04
compiled
November
12,
2002).
PRZM
simulates
processes
such
like
runoff
and
erosion
from
an
agricultural
field
on
a
daily
time
step.
The
runoff
and
erosion
flux
output
data
from
PRZM
are
used
as
chemical
loadings
to
the
EXAMS
surface
water
program
in
order
to
predict
the
EECs.
A
graphical
user
interface
(
pe4v01.
pl)
developed
by
the
EPA
(
http://
www.
epa.
gov/
oppefed1/
models/
water)
was
used
to
facilitate
inputting
chemical
and
use
specific
parameters
into
the
appropriate
PRZM
input
files
(
inp)
and
EXAMS
chemical
files.

PRZM
is
a
one­
dimensional,
dynamic,
compartmental
model
that
can
be
used
to
simulate
chemical
movement
in
unsaturated
soil
systems
within
and
immediately
below
the
plant
root
zone.
It
has
two
major
components:
hydrology
(
and
hydraulics)
and
chemical
transport.
The
hydrologic
component
for
calculating
runoff
and
erosion
is
based
on
the
Soil
Conservation
Service
curve
number
technique
and
the
Universal
Soil
Loss
Equation.
Evapotranspiration
is
estimated
either
directly
from
pan
evaporation
data,
or
based
on
an
empirical
formula.
Water
movement
is
simulated
by
the
use
of
generalized
soil
parameters,
including
field
capacity,
wilting
point,
and
saturation
water
content.

The
chemical
transport
component
can
simulate
pesticides
or
other
chemicals.
For
pesticides,
the
transport
component
can
simulate
pesticide
application
on
the
soil
or
on
the
plant
foliage.
Biodegradation
can
also
be
considered
in
the
root
zone.
Dissolved,
adsorbed,
and
vapor­
phase
­
8­
concentrations
in
the
soil
are
estimated
by
simultaneously
considering
the
processes
of
pesticide
uptake
by
plants,
surface
runoff,
erosion,
decay,
volatilization,
foliar
washoff,
advection,
dispersion,
and
retardation.
For
nitrogen,
simulation
of
surface
applications,
atmospheric
deposition,
and
septic
effluent
discharge
may
all
be
simulated.

EXAMS
is
a
model
that
has
a
set
of
process
modules
that
link
fundamental
chemical
properties
to
limnological
processes
that
control
the
kinetics
and
transport
of
chemicals
in
aquatic
systems.
It
provides
facilities
for
steady
state
or
long­
term
evaluation
of
chronic
chemical
discharges,
initialvalue
approaches
for
studying
short­
term
contaminant
releases,
and
full
kinetic
simulations
that
allow
for
monthly
variation
in
mean
climatological
factors,
and
changes
in
contaminant
loadings
on
daily
time
scales.
It
is
fairly
and
relatively
complex
model
that
requires
more
input
variables,
ranging
from
hydro­
geological
and
weather
data
to
pesticide
physicochemical
properties,
mobility
coefficients,
and
degradation
rate
constants
in
the
aqueous
and
sediment
phases.

PRZM
CROP
SCENARIOS:

Four
PRZM
scenarios
exist
for
cotton
crop
usage
:
California,
Mississippi,
North
Carolina
and
Texas.
Each
of
these
were
modeled
using
the
same
application
rates
and
use
patterns.
The
California
scenario
is
based
on
data
from
Fresno
County
in
the
Central
Valley
region
using
a
Twisselman
clay
as
the
representative
soil
for
this
region.
This
soil
is
a
fine,
mixed,
calcareous,
thermic
Typic
Torriorthents
of
hydrologic
group
C.
The
Mississippi
scenario
arises
from
Yazoo
County
and
uses
a
Loring
silt
loam
as
the
representative
soil.
Loring
silt
loam
is
a
fine­
silty,
mixed,
active,
thermic,
Qxyaquic
Fragiudalfs
of
hydrologic
group
C.
The
representative
soil
in
the
North
Carolina
PRZM
scenario
is
a
Boswell
fine
sandy
loam
of
hydrologic
group
D,
characteristic
of
the
Piedmont/
Coastal
Plain
region.
The
soil
selected
to
simulate
the
Texas
scenario
is
a
Crockett
fine
sandy
loam.
Crockett
fine
sandy
loam
is
a
fine,
smectitic,
thermic
Udertic
Paleustalfs
of
hydrologic
group
C.
Since
cotton
growth
requires
a
relatively
long
period
of
warm
temperatures
(
190­
210
days
at
temperatures
of
60
oF
and
above),
it
is
typically
planted
in
the
spring
with
crop
maturity
occurring
roughly
4
months
after
the
planting
date.
While
late
season
planting
can
occur
up
to
June
in
many
southern
states,
it
is
not
advisable
to
begin
planting
after
mid
May
because
of
the
steep
decline
in
yield
(
the
best
yields
usually
occur
with
early
season
planting,
optimal
soil
temperature
and
moisture
and
air
temperature).
Harvest
typically
occurs
from
September
1,
through
December.
It
is
not
advisable
to
use
pyrethroid
insecticides
on
cotton
crops
prior
to
July
1
unless
infestations
are
high
in
order
to
avoid
insect
resistence
later
in
the
season
(
Roof
2004).

The
field
used
to
represent
onion
production
in
California
is
located
in
Kern
County
in
the
San
Joaquin
Valley,
although
onion
production
areas
are
quite
extensive
(
San
Joaquin,
Coastal­
Intermediate
Region,
Imperial
Valley,
southern
and
central
coastal
regions,
the
high
desert
areas
of
Los
Angeles
County
and
the
northern
mountain
valleys).
According
to
the
1997
Census
of
Agriculture,
California
is
the
major
producer
of
onions
for
the
market.
Bulb
onions
are
planted
from
September
through
May
and
harvesting
begins
in
April
or
May
and
completed
by
September.
Onions
are
cools
season,
biennial
plants
that
are
commercially
grown
as
an
annual.
Plant
canopy
can
approach
100
percent
in
some
narrow
row
fields
grown
under
drip
irrigation.
Irrigation
is
required
to
avoid
seed
or
plant
dry
out.
Onions
can
grow
on
a
wide
range
of
soils.
­
9­
The
soil
selected
to
represent
the
field
is
Ciervo
clay.
Ciervo
clay,
is
a
fine,
semetic,
thermic
Vertic
Haplocambids.
These
soils
are
often
used
for
onion
and
other
truck
crop
production
under
irrigation.
The
Ciervo
clay
has
very
slow
permeability.
Ciervo
clay
is
a
Hydrologic
Group
D
soil.

Only
one
validated
PRZM
scenario
currently
exists
for
lettuce
(
California).
The
representative
soil
type
is
a
Placentia
sandy
loam
(
hydrologic
Group
D).
Lettuce
is
a
year­
round
crop
in
California,
so
the
application
timing
of
cypermethrin
can
vary
(
Jackson
et
al.
1996).
Lettuce
is
usually
planted
at
depths
of
approximately
1/
8
to
1/
4
inches
primarily
on
40­
inch
raised
beds
with
2
seedlines
per
bed.
For
a
midsummer
planting,
the
harvest
usually
begins
70­
80
days
later
and
cypermethrin
is
typically
foliar
applied
as
needed
following
emergence.
­
10­
Appendix
B.
References
EPA
2003a.
Use
of
Regional
Percent
Crop
Area
Factors
in
Refined
Drinking
Water
Assessments.
US
EPA
Office
of
Pesticide
Programs
(
OPP)
Environmental
Fate
and
Effects
Division
(
EFED)
Water
Quality
Technical
Team
(
WQTT)
July
25,
2003
EPA
2003b.
Pesticide
Root
Zone
Model
Field
and
Orchard
Crop
Scenario
Metadata.
February
06,
2003
Gorsuch
CS.
Clemson
University
Pest
Management
Handbook.
Fruits
and
Nuts
(
last
updated
3­
11­
2003).
http://
cufan.
clemson.
edu/
pmguide/
main.
htm
Jackson
L.,
Mayberry
K.,
Laemmlen
F.,
Koike
S.,
Schulbach
K.,
Chaney
W.
Iceberg
lettuce
production
in
California.
Vegetable
Research
and
Information
Center
Univ
of
California
Div
of
Agriculture
and
Natural
Resources.
Publication
Number
7215
(
1996).

Laskowski
D.
A.
2002.
Physical
and
Chemical
Properties
of
Pyrethroids.
Rev.
Environ.
Contam.
Toxicol.
174:
49­
170
NCFAP.
2003.
National
Center
for
Food
and
Agricultural
Policy,
National
Pesticide
Use
Database.
Information
taken
on
February
28,
2005
from
the
website:
http://
www.
ncfap.
org/
database/
default.
htm.

Roof
ME.
Clemson
University
Pest
Management
Handbook.
Cotton
Insect
Control
(
last
updated
5­
26­
2004).
http://
cufan.
clemson.
edu/
pmguide/
main.
htm
Tomlin
C.
1994.
Pesticide
Manual
10th
edition.
British
Crop
Protection
Council.
The
Royal
Society
of
Chemistry,
Cambridge
U.
K.

Willis
and
McDowell
1987,
as
cited
in
Carsel,
R.
F.,
et.
al.,
"
PRZM­
3,
A
Model
for
Predicting
Pesticide
and
Nitrogen
Fate
in
the
Crop
Root
and
Unsaturated
Soil
Zones:
User's
Manual
for
Release
3.0."
National
Exposure
Research
Laboratory
USEPA,
Athens,
GA;
AQUA
TERRA
Consultants,
Mountain
View,
CA;
and
Waterborne
Environmental,
Inc.,
Leesburg,
VA.
p.
5­
12.
­
11­
Appendix
C.
Output
files
from
SCI­
GROW
and
PRZM/
EXAMS
SCI­
GROW
SCIGROW
VERSION
2.3
ENVIRONMENTAL
FATE
AND
EFFECTS
DIVISION
OFFICE
OF
PESTICIDE
PROGRAMS
U.
S.
ENVIRONMENTAL
PROTECTION
AGENCY
SCREENING
MODEL
FOR
AQUATIC
PESTICIDE
EXPOSURE
SciGrow
version
2.3
chemical:
Cypermethrin
time
is
5/
2/
2005
14:
37:
25
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Application
Number
of
Total
Use
Koc
Soil
Aerobic
rate
(
lb/
acre)
applications
(
lb/
acre/
yr)
(
ml/
g)
metabolism
(
days)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
0.100
6.0
0.600
2.08E+
04
60.2
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
groundwater
screening
cond
(
ppb)
=
3.60E­
03*
*
Estimated
concentrations
of
chemicals
with
Koc
values
greater
than
9995
ml/
g
are
beyond
the
scope
of
the
regression
data
used
in
SCI­
GROW
development.
If
there
are
concerns
for
such
chemicals,
a
higher
tier
groundwater
exposure
assessment
should
be
considered,
regardless
of
the
concentration
returned
by
SCI­
GROW.
************************************************************************

PRZM/
EXAMS
Note:
The
output
concentrations
have
not
been
adjusted
by
the
PCA
factor
in
these
files.
The
adjustment
is
reflected
in
table
4
Cotton
California
stored
as
CottonCA.
out
Chemical:
Cypermethrin
PRZM
environment:
CAcottonC.
txt
modified
Friday,
6
December
2002
at
06:
50:
06
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
10:
34:
12
Metfile:
w93193.
dvf
modified
Wedday,
3
July
2002
at
04:
04:
24
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
0.6109
0.3484
0.2565
0.0991
0.06724
0.01687
1962
0.6129
0.3508
0.2589
0.1006
0.06837
0.01731
1963
0.6166
0.3549
0.2622
0.1028
0.06998
0.01773
1964
0.6127
0.3504
0.2586
0.1004
0.06829
0.01724
1965
0.6149
0.3529
0.2606
0.1017
0.06925
0.01755
­
12­
1966
0.6157
0.3539
0.2614
0.1019
0.06919
0.01751
1967
0.6085
0.3457
0.2548
0.09772
0.06605
0.01661
1968
0.6109
0.3484
0.257
0.09969
0.06785
0.01713
1969
0.6128
0.3506
0.2587
0.1005
0.06825
0.01748
1970
0.6093
0.3466
0.2555
0.09847
0.0668
0.01694
1971
0.611
0.3486
0.2571
0.09934
0.06738
0.01701
1972
0.6121
0.3497
0.2581
0.09996
0.06788
0.01715
1973
0.6133
0.3511
0.2592
0.1008
0.06857
0.0174
1974
0.6124
0.3501
0.2584
0.1002
0.06803
0.01717
1975
0.6161
0.3544
0.2618
0.1027
0.07004
0.01773
1976
0.6148
0.3528
0.2605
0.1023
0.07011
0.01797
1977
0.6108
0.3483
0.2569
0.09921
0.06726
0.017
1978
0.6102
0.3476
0.2563
0.0988
0.06713
0.01693
1979
0.611
0.3485
0.2571
0.09938
0.06733
0.01688
1980
0.6087
0.3458
0.2549
0.09805
0.06642
0.01666
1981
0.6073
0.3443
0.2537
0.09711
0.06564
0.01646
1982
0.6129
0.3507
0.2588
0.1004
0.0683
0.01731
1983
0.6154
0.3536
0.2611
0.1016
0.06884
0.01743
1984
0.6034
0.3398
0.25
0.09496
0.06402
0.01595
1985
0.6052
0.3419
0.2517
0.09617
0.06512
0.01636
1986
0.611
0.3485
0.2571
0.09891
0.0669
0.01686
1987
0.6182
0.3567
0.2637
0.1034
0.07033
0.0177
1988
0.6054
0.3422
0.2519
0.09625
0.06509
0.01629
1989
0.6098
0.3472
0.256
0.09878
0.06705
0.01685
1990
0.608
0.3451
0.2543
0.09766
0.06612
0.01662
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.1
0.61606
0.35435
0.26176
0.10266
0.070034
0.017727
Average
of
yearly
averages:
0.01707
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
CottonCA
Metfile:
w93193.
dvf
PRZM
scenario:
CAcottonC.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.04
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
1­
7
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
­
13­
Interval
1
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
5
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
1
UPTKF
Record
18:
PLVKRT
PLDKRT
0.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)
Write
Benthic
Porewater
File?
benthic
0
Write
Benthic
Sediment
File?
benthicsed
0
Cotton
Mississippi
stored
as
CottonMS.
out
Chemical:
Cypermethrin
PRZM
environment:
CAonionC.
txt
modified
Monday,
23
December
2002
at
05:
48:
48
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
10:
34:
12
Metfile:
w03940.
dvf
modified
Wedday,
3
July
2002
at
04:
05:
46
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
1.294
0.8689
0.4102
0.2243
0.1601
0.04901
1962
0.7856
0.4131
0.2657
0.1317
0.1018
0.03352
1963
2.187
1.036
0.4336
0.1766
0.1212
0.03677
1964
1.24
0.5311
0.3216
0.1919
0.1415
0.05652
1965
2.26
1.176
0.3197
0.1456
0.1579
0.05247
1966
1.734
0.7583
0.2785
0.2056
0.1549
0.04914
1967
0.687
0.3941
0.3014
0.1571
0.1182
0.03941
1968
0.6447
0.3617
0.2586
0.1339
0.09727
0.03297
1969
1.509
0.6197
0.3031
0.181
0.1295
0.03999
1970
1.036
0.4287
0.2561
0.1404
0.1331
0.05081
1971
1.138
0.5153
0.335
0.1948
0.1612
0.05147
1972
0.6268
0.355
0.2627
0.1317
0.0973
0.03513
1973
0.6045
0.3406
0.2508
0.1086
0.08734
0.03431
1974
0.6383
0.3615
0.2591
0.1352
0.1185
0.04385
1975
3.933
1.602
0.5744
0.325
0.2379
0.07385
1976
0.8993
0.5919
0.3304
0.1707
0.1447
0.04671
1977
1.08
0.6076
0.3262
0.175
0.1371
0.04835
1978
0.9796
0.56
0.315
0.1313
0.09914
0.03721
1979
3.381
1.565
0.7158
0.3673
0.2747
0.08552
1980
0.612
0.3393
0.2636
0.1153
0.08078
0.03044
1981
1.287
0.6196
0.3348
0.1415
0.1139
0.03842
1982
2.043
0.9086
0.513
0.3084
0.216
0.07078
1983
1.08
0.4434
0.272
0.149
0.1118
0.04244
1984
1.492
0.7043
0.3354
0.1887
0.1363
0.05006
1985
2.36
0.9698
0.3074
0.2285
0.1714
0.05328
1986
1.327
0.5493
0.3526
0.1695
0.1274
0.04415
1987
0.6063
0.3427
0.2592
0.1366
0.09617
0.03237
1988
0.9502
0.5307
0.3062
0.1462
0.1057
0.04024
1989
0.8184
0.48
0.3186
0.1355
0.1048
0.04127
1990
0.6208
0.3517
0.2592
0.103
0.08958
0.03481
­
14­
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.1
2.35
1.162
0.50506
0.30041
0.21154
0.069354
Average
of
yearly
averages:
0.0458423333333333
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
CottonMS
Metfile:
w03940.
dvf
PRZM
scenario:
CAonionC.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.04
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
1­
7
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
Interval
1
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
5
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
1
UPTKF
Record
18:
PLVKRT
PLDKRT
.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)
Write
Benthic
Porewater
File?
benthic
Write
Benthic
Sediment
File?
benthicsed
Cotton
North
Carolina
stored
as
CottonNC.
out
Chemical:
Cypermethrin
PRZM
environment:
NCcottonC.
txt
modified
Friday,
6
December
2002
at
08:
14:
40
­
15­
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
10:
34:
12
Metfile:
w13722.
dvf
modified
Wedday,
3
July
2002
at
04:
05:
50
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
1.822
0.8207
0.3655
0.269
0.2069
0.05829
1962
2.846
1.274
0.7578
0.353
0.2549
0.0783
1963
1.125
0.494
0.2877
0.1376
0.09743
0.04555
1964
2.09
0.968
0.4298
0.275
0.238
0.07862
1965
2.719
1.323
0.5334
0.3374
0.2443
0.07185
1966
2.355
0.9852
0.4319
0.2559
0.1913
0.05691
1967
1.998
0.8431
0.3812
0.2716
0.2119
0.063
1968
3.412
1.608
0.6143
0.3001
0.2309
0.07346
1969
3.211
1.57
0.5946
0.3667
0.2779
0.0824
1970
2.937
1.317
0.6014
0.3466
0.2494
0.07206
1971
1.855
0.9675
0.4636
0.323
0.2495
0.0745
1972
2.971
1.419
0.6904
0.3872
0.2837
0.08212
1973
2.265
1.054
0.4831
0.3214
0.235
0.06792
1974
1.949
0.9601
0.3797
0.2457
0.1932
0.05781
1975
5.266
3.391
1.008
0.4438
0.32
0.08925
1976
1.786
0.7545
0.2605
0.1168
0.1261
0.04423
1977
1.448
0.6314
0.2886
0.2049
0.1745
0.05664
1978
5.485
2.272
0.6986
0.3195
0.2252
0.06654
1979
3.411
1.432
0.6556
0.3246
0.2565
0.07655
1980
1.348
0.5586
0.2685
0.1511
0.1383
0.04554
1981
2.625
1.114
0.5066
0.3323
0.2575
0.07694
1982
0.8976
0.3848
0.2617
0.1604
0.1161
0.04308
1983
0.6274
0.3517
0.2599
0.1095
0.07946
0.03825
1984
5.433
2.728
1.104
0.5139
0.3621
0.1022
1985
4.779
2.035
0.6108
0.3809
0.2769
0.07982
1986
1.824
0.9156
0.4323
0.342
0.2514
0.07123
1987
2.371
0.9961
0.371
0.1901
0.1816
0.0567
1988
1.435
0.6042
0.3041
0.1963
0.1802
0.05817
1989
2.823
1.287
0.5291
0.3507
0.2616
0.07916
1990
0.8369
0.4513
0.295
0.1372
0.096
0.04047
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.1
5.2173
2.2483
0.75188
0.38657
0.28312
0.082372
Average
of
yearly
averages:
0.066252
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
CottonNC
Metfile:
w13722.
dvf
PRZM
scenario:
NCcottonC.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.04
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
­
16­
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
1­
7
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
Interval
1
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
5
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
3
UPTKF
Record
18:
PLVKRT
PLDKRT
.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)
Write
Benthic
Porewater
File?
benthic
Write
Benthic
Sediment
File?
benthicsed
Cotton
Texas
stored
as
CottonTX.
out
Chemical:
Cypermethrin
PRZM
environment:
TXcottonC.
txt
modified
Friday,
6
December
2002
at
08:
25:
18
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
10:
34:
12
Metfile:
w13958.
dvf
modified
Wedday,
3
July
2002
at
04:
06:
24
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
1.577
0.8782
0.4497
0.1831
0.1439
0.03805
1962
1.133
0.4547
0.2521
0.1278
0.09677
0.02687
1963
0.6046
0.3411
0.251
0.09555
0.06487
0.01705
1964
0.6067
0.3434
0.2531
0.09779
0.0755
0.02353
1965
0.6073
0.3442
0.2536
0.0995
0.07863
0.02501
1966
0.6066
0.3434
0.2529
0.1351
0.09717
0.026
1967
0.6067
0.3435
0.2537
0.1036
0.08379
0.02615
1968
1.039
0.5805
0.3312
0.1303
0.09437
0.02719
1969
0.6044
0.3408
0.2509
0.126
0.08919
0.02477
1970
0.6084
0.3454
0.2546
0.09779
0.07011
0.02002
1971
0.8563
0.427
0.2516
0.1392
0.09671
0.02576
1972
0.6115
0.349
0.2642
0.1044
0.07122
0.02036
1973
0.9996
0.5834
0.3205
0.1256
0.1002
0.03466
1974
1.198
0.5005
0.254
0.1549
0.1141
0.03354
1975
0.6942
0.4443
0.2827
0.116
0.08549
0.02562
1976
0.7866
0.4442
0.3059
0.1208
0.09663
0.02871
1977
0.6061
0.3428
0.2524
0.09641
0.06923
0.01932
1978
0.6041
0.3405
0.2506
0.1138
0.08269
0.02342
1979
2.672
1.104
0.5084
0.2583
0.179
0.04727
1980
0.6012
0.3371
0.2478
0.09418
0.06786
0.01897
­
17­
1981
0.6692
0.4145
0.2779
0.1068
0.0844
0.02623
1982
0.6038
0.3401
0.2503
0.09516
0.06434
0.01757
1983
1.098
0.4808
0.3043
0.1247
0.08769
0.02373
1984
0.6059
0.3425
0.2522
0.09644
0.06549
0.02177
1985
0.6443
0.3542
0.2625
0.1009
0.07352
0.02417
1986
0.6045
0.341
0.251
0.09583
0.07742
0.02613
1987
0.8617
0.3565
0.2732
0.1097
0.09496
0.02722
1988
0.6083
0.3458
0.2547
0.09938
0.06712
0.0176
1989
0.6061
0.3428
0.2525
0.1035
0.07118
0.01902
1990
0.8209
0.4617
0.2883
0.113
0.07683
0.02324
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.1
1.1915
0.58311
0.33013
0.15333
0.11271
0.034548
Average
of
yearly
averages:
0.0252983333333333
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
CottonTX
Metfile:
w13958.
dvf
PRZM
scenario:
TXcottonC.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.04
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
1­
7
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
Interval
1
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Interval
5
interval
3
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
1
UPTKF
Record
18:
PLVKRT
PLDKRT
.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)
­
18­
Write
Benthic
Porewater
File?
benthic
Write
Benthic
Sediment
File?
benthicsed
California
Onions
stored
as
Cypermethrin.
out
Chemical:
Cypermethrin
PRZM
environment:
CAonion0C.
txt
modified
Tueday,
8
June
2004
at
12:
01:
56
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
15:
34:
12
Metfile:
w23155.
dvf
modified
Wedday,
3
July
2002
at
09:
04:
20
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
0.5165
0.2212
0.1443
0.08728
0.05929
0.01474
1962
0.5173
0.2224
0.146
0.08886
0.06069
0.0152
1963
0.5178
0.2231
0.1462
0.08936
0.06143
0.01545
1964
0.5175
0.2223
0.1461
0.08905
0.06087
0.01516
1965
0.5181
0.2239
0.1464
0.08958
0.06154
0.01545
1966
0.5158
0.2193
0.1435
0.08722
0.05968
0.01505
1967
0.5175
0.2227
0.1458
0.08897
0.06077
0.01522
1968
0.515
0.219
0.1429
0.08647
0.05872
0.01463
1969
0.5156
0.2197
0.1429
0.08675
0.05911
0.01471
1970
0.5143
0.2166
0.1413
0.08545
0.05797
0.01449
1971
0.5184
0.2244
0.1477
0.0893
0.0608
0.01516
1972
0.5444
0.2289
0.1448
0.08722
0.05937
0.01479
1973
0.513
0.2146
0.1395
0.08411
0.05709
0.01423
1974
0.5145
0.2175
0.1418
0.0858
0.05832
0.01492
1975
0.5145
0.2175
0.1419
0.08583
0.0584
0.01462
1976
0.5144
0.217
0.1413
0.08549
0.05818
0.01447
1977
0.516
0.2202
0.1434
0.08672
0.05883
0.01513
1978
0.515
0.218
0.1424
0.08629
0.0587
0.01495
1979
0.5136
0.2158
0.1405
0.08481
0.05763
0.01432
1980
0.5184
0.2238
0.1471
0.08993
0.0616
0.01532
1981
0.514
0.2171
0.141
0.08507
0.05767
0.01438
1982
0.5145
0.2176
0.1415
0.08574
0.05833
0.01457
1983
0.5171
0.2215
0.1453
0.08861
0.06085
0.01572
1984
0.5164
0.2212
0.1441
0.08772
0.05989
0.01493
1985
0.5156
0.2203
0.1439
0.08719
0.05931
0.01489
1986
0.516
0.2197
0.1439
0.08741
0.05976
0.01495
1987
0.5155
0.2187
0.1431
0.08686
0.05955
0.01523
1988
0.5173
0.2216
0.1457
0.08876
0.06053
0.01509
1989
0.5166
0.2205
0.1447
0.08808
0.0602
0.01502
1990
0.5166
0.2208
0.1448
0.08807
0.06007
0.01496
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.032258064516129
0.5444
0.2289
0.1477
0.08993
0.0616
0.01572
0.0645161290322581
0.5184
0.2244
0.1471
0.08958
0.06154
0.01545
0.0967741935483871
0.5184
0.2239
0.1464
0.08936
0.06143
0.01545
0.129032258064516
0.5181
0.2238
0.1462
0.0893
0.06087
0.01532
0.161290322580645
0.5178
0.2231
0.1461
0.08905
0.06085
0.01523
0.193548387096774
0.5175
0.2227
0.146
0.08897
0.0608
0.01522
­
19­
0.225806451612903
0.5175
0.2224
0.1458
0.08886
0.06077
0.0152
0.258064516129032
0.5173
0.2223
0.1457
0.08876
0.06069
0.01516
0.290322580645161
0.5173
0.2216
0.1453
0.08861
0.06053
0.01516
0.32258064516129
0.5171
0.2215
0.1448
0.08808
0.0602
0.01513
0.354838709677419
0.5166
0.2212
0.1448
0.08807
0.06007
0.01509
0.387096774193548
0.5166
0.2212
0.1447
0.08772
0.05989
0.01505
0.419354838709677
0.5165
0.2208
0.1443
0.08741
0.05976
0.01502
0.451612903225806
0.5164
0.2205
0.1441
0.08728
0.05968
0.01496
0.483870967741936
0.516
0.2203
0.1439
0.08722
0.05955
0.01495
0.516129032258065
0.516
0.2202
0.1439
0.08722
0.05937
0.01495
0.548387096774194
0.5158
0.2197
0.1435
0.08719
0.05931
0.01493
0.580645161290323
0.5156
0.2197
0.1434
0.08686
0.05929
0.01492
0.612903225806452
0.5156
0.2193
0.1431
0.08675
0.05911
0.01489
0.645161290322581
0.5155
0.219
0.1429
0.08672
0.05883
0.01479
0.67741935483871
0.515
0.2187
0.1429
0.08647
0.05872
0.01474
0.709677419354839
0.515
0.218
0.1424
0.08629
0.0587
0.01471
0.741935483870968
0.5145
0.2176
0.1419
0.08583
0.0584
0.01463
0.774193548387097
0.5145
0.2175
0.1418
0.0858
0.05833
0.01462
0.806451612903226
0.5145
0.2175
0.1415
0.08574
0.05832
0.01457
0.838709677419355
0.5144
0.2171
0.1413
0.08549
0.05818
0.01449
0.870967741935484
0.5143
0.217
0.1413
0.08545
0.05797
0.01447
0.903225806451613
0.514
0.2166
0.141
0.08507
0.05767
0.01438
0.935483870967742
0.5136
0.2158
0.1405
0.08481
0.05763
0.01432
0.967741935483871
0.513
0.2146
0.1395
0.08411
0.05709
0.01423
0.1
0.51837
0.22389
0.14638
0.089354
0.061374
0.015437
Average
of
yearly
averages:
0.014925
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
Cypermethrin
Metfile:
w23155.
dvf
PRZM
scenario:
CAonion0C.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
­
20­
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.040
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0.0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
10­
05
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
Interval
1
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
1
UPTKF
0
Record
18:
PLVKRT
0
PLDKRT
0.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)

California
Lettuce
stored
as
lettuce_
California.
out
Chemical:
Cypermethrin
PRZM
environment:
CAlettuceC1.
txt
modified
Thuday,
17
February
2005
at
15:
15:
33
EXAMS
environment:
ir298.
exv
modified
Thuday,
29
August
2002
at
10:
34:
12
Metfile:
w23273.
dvf
modified
Wedday,
3
July
2002
at
08:
04:
22
Water
segment
concentrations
(
ppb)

Year
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
1961
0.527
0.237
0.1567
0.1122
0.0809
0.02578
1962
0.5292
0.24
0.1592
0.1148
0.08369
0.0327
1963
0.5276
0.2367
0.1575
0.113
0.08325
0.02755
1964
0.5292
0.2398
0.1593
0.1146
0.08867
0.03054
1965
0.5456
0.2472
0.1588
0.1143
0.08266
0.03201
1966
0.5291
0.2394
0.1593
0.1146
0.08291
0.03206
1967
0.5293
0.2394
0.1594
0.1147
0.08298
0.0318
1968
0.5279
0.2379
0.1578
0.1133
0.09006
0.02681
1969
0.53
0.2406
0.1601
0.1155
0.08383
0.03498
1970
0.5298
0.2402
0.16
0.1152
0.08366
0.03189
1971
0.529
0.2393
0.159
0.1144
0.08307
0.02759
1972
0.5286
0.2391
0.1586
0.114
0.08388
0.03002
1973
0.5301
0.2406
0.1603
0.1156
0.08391
0.0385
1974
0.7126
0.3176
0.16
0.1154
0.08593
0.04074
­
21­
1975
0.5298
0.2405
0.1599
0.1153
0.08394
0.03005
1976
0.7596
0.3508
0.1932
0.1564
0.1256
0.039
1977
0.5282
0.2382
0.1581
0.1137
0.08211
0.02933
1978
1.148
0.6764
0.2604
0.1586
0.1181
0.04938
1979
0.5287
0.2382
0.1588
0.1144
0.08294
0.02996
1980
0.5284
0.2385
0.1583
0.1139
0.08233
0.03276
1981
0.528
0.2379
0.1578
0.1135
0.08285
0.03021
1982
0.5276
0.2368
0.1574
0.113
0.08169
0.02908
1983
0.5244
0.2317
0.1534
0.1098
0.08225
0.03662
1984
0.524
0.2308
0.153
0.1092
0.07765
0.0257
1985
0.5272
0.2368
0.157
0.1126
0.08133
0.02821
1986
0.5285
0.239
0.1584
0.1175
0.08587
0.02933
1987
0.5282
0.2384
0.1581
0.1137
0.0839
0.03015
1988
0.5276
0.238
0.1573
0.1131
0.08173
0.02862
1989
0.5284
0.2387
0.1583
0.114
0.08255
0.02523
1990
0.5265
0.2362
0.1561
0.1122
0.08074
0.02415
Sorted
results
Prob.
Peak
96
hr
21
Day
60
Day
90
Day
Yearly
0.1
0.6959
0.31056
0.16028
0.11731
0.089921
0.03895
Average
of
yearly
averages:
0.0313583333333333
Inputs
generated
by
pe4.
pl
­
8­
August­
2003
Data
used
for
this
run:
Output
File:
lettuce_
California
Metfile:
w23273.
dvf
PRZM
scenario:
CAlettuceC1.
txt
EXAMS
environment
file:
ir298.
exv
Chemical
Name:
Cypermethrin
Description
Variable
Name
Value
Units
Comments
Molecular
weight
mwt
416.3
g/
mol
Henry's
Law
Const.
henry
3.4e­
7
atm­
m^
3/
mol
Vapor
Pressure
vapr
2.5e­
9
torr
Solubility
sol
0.04
mg/
L
Kd
Kd
mg/
L
Koc
Koc
141700
mg/
L
Photolysis
half­
life
kdp
36.2
days
Half­
life
Aerobic
Aquatic
Metabolism
kbacw
11.3
days
Halfife
Anaerobic
Aquatic
Metabolism
kbacs
19.3
days
Halfife
Aerobic
Soil
Metabolism
asm
62
days
Halfife
Hydrolysis:
pH
5
0
days
Half­
life
Hydrolysis:
pH
7
0
days
Half­
life
Hydrolysis:
pH
9
1.9
days
Half­
life
Method:
CAM
2
integer
See
PRZM
manual
Incorporation
Depth:
DEPI
0
cm
Application
Rate:
TAPP
0.112
kg/
ha
Application
Efficiency:
APPEFF
0.95
fraction
Spray
Drift
DRFT
0.16
fraction
of
application
rate
applied
to
pond
Application
Date
Date
1­
8
dd/
mm
or
dd/
mmm
or
dd­
mm
or
dd­
mmm
Interval
1
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
2
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
3
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
4
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Interval
5
interval
7
days
Set
to
0
or
delete
line
for
single
app.
Record
17:
FILTRA
IPSCND
1
UPTKF
­
22­
Record
18:
PLVKRT
PLDKRT
0.13
FEXTRC
0.5
Flag
for
Index
Res.
Run
IR
IR
Flag
for
runoff
calc.
RUNOFF
total
none,
monthly
or
total(
average
of
entire
run)
Write
Benthic
Porewater
File?
benthic
0
Write
Benthic
Sediment
File?
benthicsed
0