Document ID: EPA-HQ-OPP-2002-0146-0004
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2002-06-25T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
DATE:
February
20,
2002
SUBJECT:
Addendum
to
Drinking
Water
Assessment
for
the
Tolerance
Reassessment
(TRED)
for
Tebuthiuron
FROM:
Mark
Corbin,
Environmental
Scientist
Environmental
Risk
Branch
1
Environmental
Fate
and
Effects
Division
(7507C)

THRU:
Dana
Spatz,
Acting
Branch
Chief
Environmental
Risk
Branch
1
Environmental
Fate
and
Effects
Division
(7507C)

TO:
Paula
Deschamp
Reregistration
Branch
II
Health
Effects
Division
(7509C)

Wilhelmena
Livingston
Special
Review
Branch
Special
Review
and
Reregistration
Division
(7508C)

EFED
has
completed
an
addendum
to
the
drinking­
water
assessment
for
the
reassessment
of
tolerances
for
the
herbicide
tebuthiuron
submitted
to
the
Health
Effects
Division
(HED).
This
assessment
considers
tebuthiuron
and
its
degradates
which
the
Health
Effects
Division
(HED)
has
determined
are
of
toxicological
concern.
Compound
104
was
identified
by
the
MARC
as
the
only
environmental
fate
degradate
of
tebuthiuron
of
toxicological
concern.
However,
insufficient
fate
data
was
available
for
compound
104.
Therefore,
EFED
elected
to
model
total
tebuthiuron
residues
(TTR)
using
a
cumulative
residue
approach.
The
assessment
strategy
adopted
in
this
addendum
was
designed
to
assess
concentrations
of
the
TTR
(tebuthiuron
plus
compound
104,
compound
105,
compound
106,
compound
107,
compound
108,
and
compound
109)
which
were
detected
in
the
environmental
fate
studies.
The
name
and
chemical
structure
of
the
degradates
are
attached
as
Appendix
A.
A
cumulative
residue
approach
was
employed
to
provide
conservative
estimated
concentrations
in
drinking
water
for
tebuthiuron
and
its
degradation
products.
In
this
approach,
the
fate
parameters
necessary
for
Tier
II
modeling
are
estimated
from
the
total
residue
data
in
the
environmental
fate
studies
previously
submitted.
For
tebuthiuron,
total
residue
data
was
evaluated
for
the
aerobic
soil
metabolism
(MRID
41328001)
half
life,
aqueous
photolysis
(MRID
41305101)
half
life,
aerobic
aquatic
(MRID
41372501)
half
life,
anaerobic
soil
metabolism
(MRID
41328002)
half
life,
and
hydrolysis
half
lives.
Additional
fate
data
(including
Koc,
Henry's
Law
constant,
vapor
pressure,
solubility,
and
molecular
weight)
were
estimated
for
Compound
104
using
published
software
(Estimation
Programs
Interface
(EPI),
Version
3.04,
1999)
which
estimates
fate
parameter
using
published
equations.
Compound
104
was
used
as
a
reference
degradate
because
it
was
the
degradate
detected
at
the
highest
concentration
in
the
environmental
fate
studies,
is
expected
to
be
a
highly
mobile
tebuthiuron
residue
in
soil
and
aquatic
environments
based
in
its
chemical
structure
and
the
fact
that
it
was
the
only
degradate
detected
in
a
Small
Scale
Retrospective
Monitoring
study.
More
detail
on
EPI
estimation
techniques
may
be
found
at
http://
syrres.
com/
interkow/
epi.
htm.

As
with
parent
tebuthiuron,
surface
water
concentrations
of
TTR
were
modeled
using
the
PRZM/
EXAMS
(Tier
II)
programs
for
pasture/
rangeland
using
EFEDs
standard
scenario
for
alfalfa
in
Texas.
The
alfalfa
scenario
was
chosen
because
its
hydrologic
and
agronomic
practices
are
expected
to
approximate
those
of
pasture/
rangeland.
Groundwater
concentrations
were
modeled
using
the
SCI­
GROW
program.
Input
parameters
used
Tier
II
(PRZM
version
3.12/
EXAMS
version
2.97.5)
modeling
were
selecting
using
Agency
guidance
("
Guidance
for
Chemistry
and
Management
Practice
Input
Parameters
for
Use
in
Modeling
the
Environmental
Fate
and
Transport
of
Pesticides"
dated
August
6,
2000)
and
EFED
calculated
degradation
rate
constants
from
review
of
registrant
submitted
environmental
fate
studies
as
note
above.

Tier
II
(PRZM
version
3.12/
EXAMS
version
2.97.5)
surface
water
modeling
for
TTR
due
to
use
of
tebuthiuron
use
on
rangeland/
pasture
at
4
pounds
active
ingredient
per
acre
(lbs
ai/
A)
using
the
index
reservoir
and
a
PCA
of
0.87
predicts
the
1
in
10
year
annual
maximum
(acute)
concentration
of
15.52
:
g/
L.
The
1
in
10
year
annual
average
concentration
(non­
cancer
chronic)
of
tebuthiuron
is
predicted
to
be
4.31
:
g/
L
.
The
36
year
annual
average
concentration
(cancer
chronic)
of
tebuthiuron
is
predicted
to
be
1.96
:
g/
L.
SCI­
GROW
(version
2.1)
modeling
estimates
the
acute
and
chronic
concentration
of
TTR
in
shallow
groundwater
is
245
:
g/
L.

A
comparison
of
the
TTR
concentrations
compared
with
the
parent
only
values
previously
submitted
are
presented
in
Table
1.
A
more
detailed
modeling
discussion
is
presented
in
Appendix
B.
Table
1.
Comparison
of
PRZM­
EXAMS
Predicted
Total
Tebuthiuron
Residue
(TTR)
Concentrations
with
Predicted
Parent
Tebuthiuron
Concentrations
in
the
Index
Reservoir
Simulation
Scenarios
Concentration
(
:
g/
L)

1
in
10
year
Mean
of
Annual
Means
Crop
and
Location
Scenario
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
Mean
Pasture,
Milam
Co.,
TX
Total
Residues
w/
PCA
(0.87)
15.5
15.3
14.3
12.2
10.9
4.3
2.0
Parent
Only
w/
PCA
(0.87)
15.1
14.4
11.5
7.0
5.2
1.5
0.6
Appendix
B
provides
a
detailed
discussion
of
the
modeling
efforts
for
PRZM/
EXAMS,
and
SCIGROW
APPENDIX
A
DEGRADATE
NAMES
and
STRUCTURES
N
N
S
N
CH
3
CH
3
C
H
3
C
H
3
O
NH
2
Table
1.
Degradates
of
Tebuthiuron
with
maximum
applied
detected
in
each
study:

Parent
/
Degradate
Name
and
Structure
Percent
of
Applied
Dose
MRID
#
Study
Type
Reported
Values
Maximum
Day
*104:
N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]­
methylurea
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
6.8
14
41050201
soil
photolysis
6.9
270
41328001
aerobic
soil
Nmetabolism
2.9
60
41328002
anaerobic
soil
metabolism
1.5
21
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
22.9
408
43318101
terrestrial
field
dissipation
2.2
(edible)
21
40819501
bioaccumulation
in
fish
105:
N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]­
N
methylurea
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
3.5
19
41050201
soil
photolysis
0.4
90
41328001
aerobic
soil
metabolism
0.2
60
41328002
anaerobic
soil
metabolism
0.4
28
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
Parent
/
Degradate
Name
and
Structure
Percent
of
Applied
Dose
MRID
#
Study
Type
Reported
Values
Maximum
Day
N
N
S
N
H
CH
3
C
H
3
C
H
3
O
NH
2
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
ND
N/
A
43318101
terrestrial
field
dissipation
4.7
(edible)
21
40819501
bioaccumulation
in
fish
106:
N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]
urea
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
2.7
5
41050201
soil
photolysis
ND
N/
A
41328001
aerobic
soil
metabolism
ND
N/
A
41328002
anaerobic
soil
metabolism
ND
N/
A
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
ND
N/
A
43318101
terrestrial
field
dissipation
ND
N/
A
40819501
bioaccumulation
in
fish
107:
5­(
1,1­
Dimethylethyl)­
2­
methylamino­
1,3,4­
thiadiazole
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
ND
N/
A
41050201
soil
photolysis
1.1
270
41328001
aerobic
soil
metabolism
ND
N/
A
41328002
anaerobic
soil
metabolism
Parent
/
Degradate
Name
and
Structure
Percent
of
Applied
Dose
MRID
#
Study
Type
Reported
Values
Maximum
Day
N
N
S
NH
2
CH
3
C
H
3
C
H
3
0.3
21
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
ND
N/
A
43318101
terrestrial
field
dissipation
ND
N/
A
40819501
bioaccumulation
in
fish
108:
2­
dimethylethyl­
5­
amino­
1,3,4­
thiadiazole
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
ND
N/
A
41050201
soil
photolysis
0.6
270
41328001
aerobic
soil
metabolism
ND
N/
A
41328002
anaerobic
soil
metabolism
0.1
7
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
ND
N/
A
43318101
terrestrial
field
dissipation
ND
N/
A
40819501
bioaccumulation
in
fish
Parent
/
Degradate
Name
and
Structure
Percent
of
Applied
Dose
MRID
#
Study
Type
Reported
Values
Maximum
Day
N
N
S
N
CH
3
CH
3
C
H
3
C
H
3
O
N
H
OH
N
N
S
N
CH
3
CH
3
C
H
3
C
H
3
O
N
H
CH
3
N
N
S
N
CH
3
CH
3
C
H
3
O
N
H
CH
3
OH
*109:
N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]­
hydroxymethyl­
methylurea
ND
N/
A
N/
A
hydrolysis
ND
N/
A
41305101
aqueous
photolysis
ND
N/
A
41050201
soil
photolysis
N'ND
N/
A
41328001
aerobic
soil
Nmetabolism
0.2
60
41328002
anaerobic
soil
metabolism
0.3
7
41372501
aerobic
aquatic
metabolism
ND
N/
A
41913101
anaerobic
aquatic
metabolism
ND
N/
A
40768401
batch
equilibrium
N/
A
N/
A
N/
A
laboratory
volatility
N/
A
N/
A
N/
A
field
volatility
ND
N/
A
43318101
terrestrial
field
dissipation
40.1
(edible)
21
40819501
bioaccumulation
in
fish
Attachment
1:
Additional
structures
of
tebuthiuron
and
its
metabolites:

Tebuthiuron
(103):
[N­[
5­(
1,1­
dimethylethyl
1,3,4­
thiadiazol­
2­
yl]­
N,
N'­
dimethylurea
Matrices:
grass
forage
and
hay,
ruminant
and
milk
103
(OH):
N­[
5­(
2­
hydroxy­
1,1­
dimethylethyl
1,3,4­
thiadiazol­
2­
yl]­
N,
N'­
dimethylurea
Matrices:
ruminant
and
milk
N
N
S
N
CH
3
CH
3
C
H
3
O
NH
2
OH
N
N
S
N
CH
3
CH
3
C
H
3
O
N
H
OH
OH
N
N
S
N
C
CH3
H3C
CH3
H
C
O
N
CH3
H
Tebuthiuron
105
N
N
S
N
C
CH3
H3C
CH3
H
CH3
Tebuthiuron
107
104
(OH):
N­[
5­(
2­
hydroxy­
1,1­
dimethylethyl
1,3,4­
thiadiazol­
2­
yl]­
N­
methylurea
Matrices:
milk
A
[109
(OH)]:
N­[
5­(
2­
hydroxy­
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]­
N
hydroxymethyl­
N­
methylurea
Matices:
milk
105:
N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl
N'­
methylurea
Matrices:
water
107:
5­(
1,1­
Dimethylethyl)­
2­
methylamino­
1,3,4­
thiadi
azol
e
Matr
ices
:wat
er
and
tissu
es
cc:
SF,
RF,
List
A
files,
S.
Piper,
M.
Corbin
RDI:
FBSuhre:
/01;
MARC:
/01
7509C:
CEB:
CM­
2:
Room
810F:
308­
2717:
Tebuthiuron
APPENDIX
B
MODELING
DISCUSSION
DRINKING
WATER
ASSESSMENT
Uncertainties,
Assumptions
and
Limitations
Input
parameters
used
in
Tier
II
(PRZM/
EXAMS)
modeling
were
selecting
using
Agency
guidance
("
Guidance
for
Chemistry
and
Management
Practice
Input
Parameters
for
Use
in
Modeling
the
Environmental
Fate
and
Transport
of"
dated
August
6,
2000)
and
EFED
calculated
degradation
rate
constants
from
review
of
registrant
submitted
environmental
fate
studies.

Tebuthiuron
is
used
primarily
on
pasture
and
rangeland
in
Texas,
Oklahoma,
and
New
Mexico,
therefore,
only
one
scenario
was
simulated
to
estimate
runoff
concentrations.
EFED
selected
a
scenario
in
Texas
for
alfalfa
representing
an
EFED
standard
scenario
developed
for
use
in
modeling
the
respective
crops
and
is
expected
to
be
the
standard
scenario
in
the
tebuthiuron
use
with
the
highest
runoff
potential.
Alfalfa
was
selected
as
the
scenario
most
closely
representing
pasture/
rangeland
(the
alfalfa
scenario
was
developed
based
on
a
pasture
setting).
These
scenarios
were
developed
to
approximately
represent
the
90
th
percentile
site
for
runoff
vulnerability
in
a
high
usage
state.
Application
timing
was
taken
from
registrant
provided
information
and
recent
labels.

The
standard
scenario
for
alfalfa
is
based
on
usage
patterns
in
Milam
County,
Texas.
The
soil
is
a
Lufkin
sandy
loam
in
Major
Land
Use
Area
(MLRA)
87.
The
Lufkin
sandy
loam
is
characterized
as
a
Hydrologic
Group
D
soil.

Uncertainties,
Assumptions
and
Limitations
There
are
several
uncertainties
and
assumptions
in
the
assessment
of
tebuthiuron
and
its
degradates.
Primary
among
these
is
the
lack
of
environmental
fate
data
for
the
transformation
products
of
tebuthiuron.
In
order
to
address
this
uncertainty,
EFED
has
conducted
the
Tier
II
modeling
(PRZM/
EXAMS)
on
the
summed
tebuthiuron
residues
(tebuthiuron
and
its
identifiable
degradation
products
including
compound
104,
compound
105,
compound
106,
compound
107,
compound
108,
and
compound
109)
instead
of
individual
residues.
Although
the
persistence
of
the
tebuthiuron
residues
was
estimated
from
registrant
submitted
environmental
fate
data,
the
mobility
of
tebuthiuron
residues
was
estimated
using
the
degradate
compound
104
(N­[
5­(
1,1­
dimethylethyl)­
1,3,4­
thiadiazol­
2­
yl]­
N­
methylurea)
as
a
reference
compound.
This
compound
was
used
to
assess
mobility
because
it
was
the
degradate
detected
at
the
highest
concentration
in
the
environmental
fate
studies,
is
expected
to
be
a
highly
mobile
tebuthiuron
residue
in
soil
and
aquatic
environments,
and
was
the
only
degradate
detected
in
a
Retrospective
Ground
Water
Study.
EFED
used
the
lowest
Kd/
Koc
value
for
tebuthiuron
as
the
Kd/
Koc
for
Compound
104.
Physical
chemistry
parameters
were
estimated
for
compound
104
(Estimation
Programs
Interface
(EPI),
Version
3.04,
1999)
and
degradation
rate
constants
were
estimated
by
performing
linear
regression
on
the
total
residues
(Microsoft
Excel
2000)
from
several
fate
studies.
Table
A­
1.
Input
Parameters
for
Total
Tebuthiuron
Residues
for
PRZM
(Version
3.12)
for
Index
Reservoir
and
PCA.

Variable
Description
Variable
(Units)
Input
Value
Source
of
Info/
Reference
Application
date(
s)
(day/
mo/
yr)
APD,
APM,
IAPYR
(day/
mo/
yr)
1
times
per
year
Product
label
or
location­
specific
Incorporation
depth
DEPI
(cm)
0
Product
label
Application
rate
TAPP
(kg
a.
i.
ha
­1
)
4.48
Aerial
granular
Product
label
Application
efficiency
APPEFF
(decimal)
1.00
Spray
Drift
Task
Force
Data
Spray
drift
fraction:
For
aquatic
ecological
exposure
assessment,
use
0.05
for
aerial
spray;
0.01
for
ground
spray.
For
drinking
water
assessment,
use
0.16
for
aerial
0.064
for
ground
spray.
DRFT
(decimal)
0.00
Spray
Drift
Task
Force
Data
Foliar
extraction
FEXTRA
(frac./
cm
rain)
0.5
(default)
Default
or
field
data
Decay
rate
on
foliage
PLDKRT
(day
­1
)
0.0
(default)
Default
or
field
data
Volatilization
rate
from
foliage
PLVKRT
(day
­1
)
0.0
(default)
Default
or
field
data
Plant
uptake
factor
UPTKF
(frac.
of
evap)
0.0
(default)
Default
or
field
data
Dissolved
phase
pesticide
decay
rate
in
surface
horizon
(aerobic
soil
metabolism)
DWRATE
(surface)
(day
­1
)
T1/
2
=>
2832
days
Rate
constant
=
0.000245/
day
MRID
41328001
Adsorbed
phase
pesticide
decay
rate
in
surface
horizon
(aerobic
soil
metabolism)
DSRATE
(surface)
(day
­1
)
T1/
2
=>
2832
days
Rate
constant
=
0.000245/
day
MRID
41328001
Dissolved
phase
pesticide
decay
rate
in
subsequent
subsurface
horizons
(aerobic
or
anaerobic
soil
metabolism)
DWRATE
(subsurface
horizons)
(day
­1
)
T1/
2
=>
2832
days
Rate
constant
=
0.000245/
day
MRID
41328001
Adsorbed
phase
pesticide
decay
rate
in
subsequent
subsurface
horizons
(aerobic
or
anaerobic
soil
metabolism)
DSRATE
(subsurface
horizons)
(day
­1
)
T1/
2
=>
2832
days
Rate
constant
=
0.000245/
day
MRID
41328001
Pesticide
partition
or
distribution
coefficients
for
each
horizon
(Leaching/
Adsorption/
Desorption)
Kd
0.11
Lowest
Kd
MRID
40768401
Table
A­
2.
Input
Parameters
for
Tebuthiuron.
chm
Files
Used
in
EXAMS
(Version
2.97.
5)
for
Index
Reservoir
and
PCA.

Variable
Description
Variable
(Units)
Input
Value
Source
of
Info/
Reference
Henry's
law
constant
HENRY
(atm­
m
3
mole
­1
)
7.58
x
10
­11
Atm
m
3
/mol
EPI
Bacterial
biolysis
in
water
column
(aerobic
aquatic
metabolism)
KBACW
(cfu/
mL)
­1
hour
­1
683
days
Rate
constant
=0.000042/
hr
MRID
41372501
Bacterial
biolysis
in
benthic
sediment
(anaerobic
aquatic
or
aerobic
aquatic
metabolism)
KBACS
1
(cfu/
mL)
­1
hour
­1
0
days
(stable)
MRID
41913101
Direct
photolysis
(aqueous
photolysis)
KDP
(hour
­1
)
T1/
2
=0
days
(stable)
MRID
41365101
Base
hydrolysis
KBH
(mole
­1
hour
­1
)
0
days
(stable)
1994
RED
Neutral
hydrolysis
KNH
(mole
­1
hour
­1
)
0
days
(stable)
1994
RED
Acid
hydrolysis
KAH
(mole
­1
hour
­1
)
0
days
(stable)
1994
RED
Partition
coefficient
for
sediments
(Leaching/
Adsorption/
Desorption)
need
Kd
from
soil
closest
to
crop
scenario
KPS
(mL
g
­1
or
L
kg
­1
)
Kd
=
0.11
Lowest
Kd
MRID
40768401
Molecular
weight
MWT
(g
mole
­1
)
214.3
EPI
Aqueous
solubility
(Multiply
water
solubility
by
10)
SOL
(mg
L
­1
)
=
0.800
2790
ppm
@
20°
C
EPI
Vapor
pressure
VAPR
(torr)
7.5
x
10
­7
Torr
EPI
Sediment
bacteria
temperature
coefficient
QTBAS
2
Standard
value
Water
bacteria
temperature
coefficient
QTBAW
2
Standard
value
TX
Alfalf
­
08/
06/
2001
"
Texas
Claypan
Area,
Milam
County,
Texas;
MLRA
J­
87"
***
Record
3:
0.71
0.36
0
25
1
1
***
Record
6
­­
ERFLAG
4
***
Record
7:
0.43
0.109
1
172.8
4
1
600
***
Record
8
1
***
Record
9
1
0.25
100
100
1
90
88
89
0
76
***
Record
9a­
d
1
26
0101
1601
0102
1602
0103
1503
1603
0104
1604
0105
1605
0106
1506
1606
0107
1607
.003
.003
.003
.004
.004
.004
.003
.001
.000
.001
.001
.000
.001
.001
.000
.000
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
0108
1608
0109
1609
0110
1610
0111
1611
0112
1612
.001
.000
.000
.001
.001
.002
.002
.002
.003
.003
.110
.110
.110
.110
.110
.110
.110
.110
.110
.110
***
Record
10
­­
NCPDS,
the
number
of
cropping
periods
36
***
Record
11
300847
201047
010848
1
300848
201048
010849
1
300849
201049
010850
1
300850
201050
010851
1
300851
201051
010852
1
300852
201052
010853
1
300853
201053
010854
1
300854
201054
010855
1
300855
201055
010856
1
300856
201056
010857
1
300857
201057
010858
1
300858
201058
010859
1
300859
201059
010860
1
300860
201060
010861
1
300861
201061
010862
1
300862
201062
010863
1
300863
201063
010864
1
300864
201064
010865
1
300865
201065
010866
1
300866
201066
010867
1
300867
201067
010868
1
300868
201068
010869
1
300869
201069
010870
1
300870
201070
010871
1
300871
201071
010872
1
300872
201072
010873
1
300873
201073
010874
1
300874
201074
010875
1
300875
201075
010876
1
300876
201076
010877
1
300877
201077
010878
1
300878
201078
010879
1
300879
201079
010880
1
300880
201080
010881
1
300881
201081
010882
1
300882
201082
010883
1
***
Record
12
­­
PTITLE
Tebuthiuron
­
1
applications
@
4.48
kg/
ha
***
Record
13
36
1
0
0
***
Record
15
­­
PSTNAM
Tebuthiuron
***
Record
16
050648
0
8
2
4.48
1
0
050649
0
8
2
4.48
1
0
050650
0
8
2
4.48
1
0
050651
0
8
2
4.48
1
0
050652
0
8
2
4.48
1
0
050653
0
8
2
4.48
1
0
050654
0
8
2
4.48
1
0
050655
0
8
2
4.48
1
0
050656
0
8
2
4.48
1
0
050657
0
8
2
4.48
1
0
050658
0
8
2
4.48
1
0
050659
0
8
2
4.48
1
0
050660
0
8
2
4.48
1
0
050661
0
8
2
4.48
1
0
050662
0
8
2
4.48
1
0
050663
0
8
2
4.48
1
0
050664
0
8
2
4.48
1
0
050665
0
8
2
4.48
1
0
050666
0
8
2
4.48
1
0
050667
0
8
2
4.48
1
0
050668
0
8
2
4.48
1
0
050669
0
8
2
4.48
1
0
050670
0
8
2
4.48
1
0
050671
0
8
2
4.48
1
0
050672
0
8
2
4.48
1
0
050673
0
8
2
4.48
1
0
050674
0
8
2
4.48
1
0
050675
0
8
2
4.48
1
0
050676
0
8
2
4.48
1
0
050677
0
8
2
4.48
1
0
050678
0
8
2
4.48
1
0
050679
0
8
2
4.48
1
0
050680
0
8
2
4.48
1
0
050681
0
8
2
4.48
1
0
050682
0
8
2
4.48
1
0
050683
0
8
2
4.48
1
0
***
Record
17
0
1
0
***
Record
19
­­
STITLE
Lufkin
Sandy
Loam;
HYDG:
D
***
Record
20
100
0
0
0
0
0
0
0
0
0
***
Record
26
0
0
0
***
Record
33
3
1
10
1.55
0.215
0
0
0
0.00022
0.00022
0
0.1
0.215
0.105
1.16
0.11
2
8
1.55
0.215
0
0
0
0.00022
0.00022
0
1
0.215
0.105
1.16
0.11
3
82
1.6
0.32
0
0
0
0.00022
0.00022
0
2
0.32
0.2
0.29
0.11
***
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
SET
MODE
=
3
CHEM
NAME
IS
Tebuthiuron
104
Read
ENV
c:\
mark\
przmexam\
exam\
irtxalf.
exv
SET
MWT(*)
=
214.3
SET
SOL(*,*)
=
2790.0
SET
PRBEN
=
0.05
SET
VAPR(
1)=
7.50E­
07
SET
HENRY(
1)
=
7.58E­
11
SET
KBACW(*,*,
1)=
0.000042
SET
KBACS(*,*,
1)=
0.0
SET
QTBAS(*,*,
1)=
2.0
SET
QTBAW(*,*,
1)=
2.0
SET
KDP(*,
1)=
0.0
SET
KBH(*,*,
1)=
0.000
SET
KNH(*,*,
1)=
0.000
SET
KAH(*,*,
1)=
0.000
SET
Koc(
1)=
15.69
SET
YEAR1
=
1948
READ
PRZM
P2E­
C1.
D48
RUN
READ
PRZM
P2E­
C1.
D49
CONTINUE
READ
PRZM
P2E­
C1.
D50
CONTINUE
READ
PRZM
P2E­
C1.
D51
CONTINUE
READ
PRZM
P2E­
C1.
D52
CONTINUE
READ
PRZM
P2E­
C1.
D53
CONTINUE
READ
PRZM
P2E­
C1.
D54
CONTINUE
READ
PRZM
P2E­
C1.
D55
CONTINUE
READ
PRZM
P2E­
C1.
D56
CONTINUE
READ
PRZM
P2E­
C1.
D57
CONTINUE
READ
PRZM
P2E­
C1.
D58
CONTINUE
READ
PRZM
P2E­
C1.
D59
CONTINUE
READ
PRZM
P2E­
C1.
D60
CONTINUE
READ
PRZM
P2E­
C1.
D61
CONTINUE
READ
PRZM
P2E­
C1.
D62
CONTINUE
READ
PRZM
P2E­
C1.
D63
CONTINUE
READ
PRZM
P2E­
C1.
D64
CONTINUE
READ
PRZM
P2E­
C1.
D65
CONTINUE
READ
PRZM
P2E­
C1.
D66
CONTINUE
READ
PRZM
P2E­
C1.
D67
CONTINUE
READ
PRZM
P2E­
C1.
D68
CONTINUE
READ
PRZM
P2E­
C1.
D69
CONTINUE
READ
PRZM
P2E­
C1.
D70
CONTINUE
READ
PRZM
P2E­
C1.
D71
CONTINUE
READ
PRZM
P2E­
C1.
D72
CONTINUE
READ
PRZM
P2E­
C1.
D73
CONTINUE
READ
PRZM
P2E­
C1.
D74
CONTINUE
READ
PRZM
P2E­
C1.
D75
CONTINUE
READ
PRZM
P2E­
C1.
D76
CONTINUE
READ
PRZM
P2E­
C1.
D77
CONTINUE
READ
PRZM
P2E­
C1.
D78
CONTINUE
READ
PRZM
P2E­
C1.
D79
CONTINUE
READ
PRZM
P2E­
C1.
D80
CONTINUE
READ
PRZM
P2E­
C1.
D81
CONTINUE
READ
PRZM
P2E­
C1.
D82
CONTINUE
READ
PRZM
P2E­
C1.
D83
CONTINUE
QUIT
Tebuthiuron
Total
Residues
on
Texas
Pasture
WATER
COLUMN
DISSOLVED
CONCENTRATION
(PPB)

YEAR
PEAK
96
HOUR
21
DAY
60
DAY
90
DAY
YEARLY
­­­­
­­­­
­­­­­­­
­­­­­­
­­­­­­
­­­­­­
­­­­­­
1948
4.843
4.762
4.514
3.926
3.511
1.338
1949
1.543
1.517
1.432
1.234
1.107
0.705
1950
10.530
10.350
9.641
8.230
7.331
2.902
1951
21.930
21.560
20.080
17.130
15.440
6.395
1952
10.370
10.200
9.497
8.111
7.227
3.798
1953
2.216
2.179
2.030
1.734
1.548
1.066
1954
0.491
0.484
0.454
0.396
0.357
0.204
1955
9.048
8.910
8.335
7.126
6.350
2.446
1956
1.610
1.586
1.486
1.289
1.160
0.578
1957
9.920
9.753
9.082
7.767
6.923
2.612
1958
5.094
5.008
4.668
3.991
3.558
1.841
1959
4.532
4.455
4.146
3.628
3.253
1.520
1960
17.620
17.320
16.200
13.840
12.340
5.088
1961
7.075
6.996
6.646
5.702
5.085
2.951
1962
16.710
16.490
15.500
13.260
11.820
4.894
1963
3.133
3.085
2.892
2.508
2.258
1.199
1964
9.535
9.374
8.756
7.494
6.681
2.599
1965
2.535
2.493
2.322
1.984
1.777
1.143
1966
3.153
3.100
2.888
2.471
2.210
0.974
1967
3.887
3.820
3.553
3.140
2.905
1.274
1968
1.029
1.013
0.950
0.823
0.742
0.414
1969
9.976
9.808
9.127
7.989
7.465
2.969
1970
2.528
2.490
2.333
2.022
1.820
0.853
1971
8.444
8.302
7.727
6.693
6.009
2.374
1972
6.418
6.310
5.879
5.030
4.486
2.192
1973
3.866
3.801
3.562
3.046
2.715
1.372
1974
1.297
1.287
1.211
1.038
0.929
0.537
1975
4.384
4.313
4.019
3.434
3.060
1.313
1976
5.983
5.882
5.528
4.736
4.233
1.850
1977
1.284
1.265
1.185
1.028
0.925
0.516
1978
18.350
18.040
16.800
14.350
12.800
4.902
1979
3.417
3.359
3.221
2.890
2.624
1.952
1980
0.888
0.875
0.821
0.713
0.642
0.342
1981
33.960
33.630
31.500
26.900
23.960
9.423
1982
6.936
6.820
6.522
5.625
5.022
3.505
1983
2.598
2.554
2.384
2.044
1.827
1.059
SORTED
FOR
PLOTTING
­­­­­­
­­­
­­­­­­­

PROB
PEAK
96
HOUR
21
DAY
60
DAY
90
DAY
YEARLY
­­­­
­­­­
­­­­­­­
­­­­­­
­­­­­­
­­­­­­
­­­­­­
0.027
33.960
33.630
31.500
26.900
23.960
9.423
0.054
21.930
21.560
20.080
17.130
15.440
6.395
0.081
18.350
18.040
16.800
14.350
12.800
5.088
0.108
17.620
17.320
16.200
13.840
12.340
4.902
0.135
16.710
16.490
15.500
13.260
11.820
4.894
0.162
10.530
10.350
9.641
8.230
7.465
3.798
0.189
10.370
10.200
9.497
8.111
7.331
3.505
0.216
9.976
9.808
9.127
7.989
7.227
2.969
0.243
9.920
9.753
9.082
7.767
6.923
2.951
0.270
9.535
9.374
8.756
7.494
6.681
2.902
0.297
9.048
8.910
8.335
7.126
6.350
2.612
0.324
8.444
8.302
7.727
6.693
6.009
2.599
0.351
7.075
6.996
6.646
5.702
5.085
2.446
0.378
6.936
6.820
6.522
5.625
5.022
2.374
0.405
6.418
6.310
5.879
5.030
4.486
2.192
0.432
5.983
5.882
5.528
4.736
4.233
1.952
0.459
5.094
5.008
4.668
3.991
3.558
1.850
0.486
4.843
4.762
4.514
3.926
3.511
1.841
0.514
4.532
4.455
4.146
3.628
3.253
1.520
0.541
4.384
4.313
4.019
3.434
3.060
1.372
0.568
3.887
3.820
3.562
3.140
2.905
1.338
0.595
3.866
3.801
3.553
3.046
2.715
1.313
0.622
3.417
3.359
3.221
2.890
2.624
1.274
0.649
3.153
3.100
2.892
2.508
2.258
1.199
0.676
3.133
3.085
2.888
2.471
2.210
1.143
0.703
2.598
2.554
2.384
2.044
1.827
1.066
0.730
2.535
2.493
2.333
2.022
1.820
1.059
0.757
2.528
2.490
2.322
1.984
1.777
0.974
0.784
2.216
2.179
2.030
1.734
1.548
0.853
0.811
1.610
1.586
1.486
1.289
1.160
0.705
0.838
1.543
1.517
1.432
1.234
1.107
0.578
0.865
1.297
1.287
1.211
1.038
0.929
0.537
0.892
1.284
1.265
1.185
1.028
0.925
0.516
0.919
1.029
1.013
0.950
0.823
0.742
0.414
0.946
0.888
0.875
0.821
0.713
0.642
0.342
0.973
0.491
0.484
0.454
0.396
0.357
0.204
1/
10
17.839
17.536
16.380
13.993
12.478
4.958
MEAN
OF
ANNUAL
VALUES
=
2.253
STANDARD
DEVIATION
OF
ANNUAL
VALUES
=
1.941
UPPER
90%
CONFIDENCE
LIMIT
ON
MEAN
=
2.732
RUN
No.
1
FOR
Compound
104
INPUT
VALUES
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

APPL
(#/
AC)
APPL.
URATE
SOIL
SOIL
AEROBIC
RATE
NO.
(#/
AC/
YR)
KOC
METABOLISM
(DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

.276
1
.276
16.0
2832.0
GROUND­
WATER
SCREENING
CONCENTRATIONS
IN
PPB
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

245.181800
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

A=
1500.000
B=
20.960
C=
3.176
D=
1.321
RILP=
8.508
F=
2.949
G=
888.340
URATE=
.276
GWSC=
245.181800