OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREV E NTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460



### PC Code: 036101

Decision #: 463234

DP Barcode: 401006

Date: Ju ly 02

, 2012

MEMORANDUM

SUBJECT: Drinking Water Exposure Assessment to Establish Tolerance s of Parent

Trifluralin and its Degradates for Oilseed Crop Group 20

.

TO: Andrew Ertman , Risk Manager Reviewer

Barbara Madden

, Risk Manager

Registration Division (7505C)

FROM: Faruque Khan

, Ph.D., Senior Fate Scientist

Nancy Andrews

, Ph.D.

, Branch Chief

Environmental Risk Branch I

Environmental Fate and Effects Division (7507P)

A screening

- level drinking water assessments was conducted for the petition submitted

by the IR

- 4 Project to ex pand canola/rapeseed, sunflower seed and cottonseed tolerance s of

trifluralin herbicide to include oilseed crop group 20. This is an abbreviated drinking water

assessment to provide estimated drinking water concentrations (EDWC s ) of trifluralin and its

major degradates (TR

- 4, TR

- 6 and TR

- 15) in surface water and ground water in support of

human health risk assessment. The assessment is based on drinking water assessment previously

performed for the T olerance Reassessment Eligibility Decision (TRED) ( D296624, December 3,

2003). The EDWCs for oilseed crops are based on the maximum proposed application rates for

aerial and ground applications specified in the proposed product label s ( Treflan ® 

### HFP

, and

Treflan ® 

### TR

- 10 )

.

Modeling was performed using a tota l toxic residue method combining trifluralin

degradates of concern [i.e. trifluralin and its major environmental degradation products (≥10% of

applied)] from fate studies. Major degradation products are TR

- 4 ( α

, α

, α

- trifluoro

- 5

- nitro

N4,N4

- dipropyl

- toluen e

- 3,4

- diamine) , TR

- 6 ( 5

- trifluoromethyl

- 3

- nitro

- 1,2

- benzenediamine) and

TR

- 15 ( 2

- ethyl

- 7

- nitro

- 5

- (trifluoromethyl) benzimidazole). The EDWCs of total toxic trifluralin

residue for various crops were generated with the coupled models PRZM and EXAMS for

surface water and SCI

- GROW for ground water. C urrent versions of surface water and ground

water models as well as the guidance of model input were updated multiple times since the

previous drinking water a ssessment was performed for the 200 3 T RED (US EPA, 2003)

. Detailed updates of various model s and the guidance for model input s can be obtained from

### 2 URL : http://www.epa.gov/oppefed1/models/water/

. Therefore, in addition to the proposed

expansion of tolerance s to oilseed crop group 20 , this assessment also re

- evaluates the existing

sugarcane use to reflect the highest EDWCs in the previous drinking water a ssessment (US EPA,

2003)

.

The upper

- bound EDWCs for trifluralin and its major degradates are provided in Table 1

for the human health risk assessment. The most conservative estimates were obtained from aerial

application of trifluralin for LA Sugarcane as a surrogate scenario for Hawaii at the maximum

labeled annual application rate of 4 lb s a.i./acre, applied twice annually at 2 lb s a.i./acre

. The

updated EDWCs for sugarcane are lower than the previousl y reported EDWCs in the TRED

(U.S. EPA 2003) due to two applications at 2.0 lbs a.i. /A as prescribed in current labels instead

of 1 application at 4.0 lbs/A per year used in the previous assessment. Based on the results of

current modeling , EFED recommends an acute EDWC of 23.83 μg/L

, a chronic EDWC of

1.97 μg/L and a cancer chronic EDWC of 1.35 μg/L for surface water be use d in the human

health risk assessment.

SCIGROW modeling was performed for oilseeds as well as sugarcane because it

rep resents the highest application rate (4.0 lbs/A). The estimated shallow groundwater

concentration for trifluralin is not likely to exceed 2.75E

- 02 μg/L (Table 1) . Since there is no

major degradate formed in soil, the predicted concentration represent total toxic residue of

trifluralin. The p redicted value also represent s both acute and chronic exposures. However,

SCIGROW predicted maximum trifluralin concentration for ground water is lower than the

concentration of 0.15 μg/L reported in NAQWA Ground Water M onitoring Database (USGS

2012 )

. EFED recommends using NAQWA groundwater monitoring value of 0.15 μg/L for acute

, chronic and cancer chronic exposures in ground water for human health risk assessment.

In conclusion, EDWCs generated by the scenarios are expected to be generally

representative of concentrations that would result from field application of trifluralin on the

simulated scenarios. EFED suggest s using above recommendations for surface and groundwater

exposur es values for human health risk assessment.

Table 1. Estimated Drinking Water Concentrations (EDWCs) of trifluralin and its

degradates for surface water using PRZM/EXAMS and groundwater using SCIGROW

Drinking Water

Source (model) Use

Scenario

(modeled rate) 1

- in

- 10 year acute

( 

### μg/L ) 1

- in

- 10 year chronic

( 

### μg/L ) 30

- year average

( 

### μg/L )

Surface Water

(PRZM/EXAMS) Sugarcane :

FL Sugarcane STD

( 2 app. X 1.0 lbs ai/acre ) 3.89 (A) 1 0.74(A) 0.59(A)

Sugarcane :

LA Sugarcane STD ( 2 app.

X 1.0 lbs ai/acre )

LA Sugercane STD 2 app.

X 2.0 lbs ai/acre ) 2 11.92(A)

23.83 (A) 3

19.37 (G) 4 0.99(A)

1.97(A) 3

1.76 (G) 4 0.80(A)

1.59(A) 3

1.35 (G) 4

### 3 Table 1. Estimated Drinking Water Concentrations (EDWCs) of trifluralin and its

degradates for surface water using PRZM/EXAMS and groundwater using SCIGROW

Drinking Water

Source (model) Use

Scenario

(modeled rate) 1

- in

- 10 year acute

( 

### μg/L ) 1

- in

- 10 year chronic

( 

### μg/L ) 30

- year average

( 

### μg/L )

Oilseed:

CA Cotton STD

1 app. X 2.0 lbs ai/acre ) 3 12.82 (A) 0.35 (A) 0.33 (A)

Oilseed:

MS Cotton STD

1 app. X 2.0 lbs ai/acre ) 3 21.35 (A) 1.08 (A) 0.84 (A)

Oilseed:

NC Cotton STD

1 app. X 2.0 lbs ai/acre ) 3 19.63 (A) 0.99 (A) 0.88 (A)

Oilseed:

ND Canola STD

1 app. X 1.25 lbs ai/acre ) 3 8.16 (A) 0.30 (A) 0.25 (A)

Groundwater

(SCI

- GROW) For sugarcane

( 2 app. X 2.0 lbs a

. i

. /acre)

Cottonseed

1 app. X 2.0 lbs/Acre

Oil Seed

1 app. X 1.25 lbs a.i. /acre 2.75 E

- 02 5

1.37E

- 02

8.58 E

- 03 2.75

- 02 5

1.37E

- 02

8.58 E

- 03 2.75 E

- 02 5

1.37E

- 02

8.58 E

- 03

1

= Aerial application

2 = LA Sugarcane STD scenario was used as a surrogate scenario to calculate EDWCs for trifluralin uses in Hawaii

3 = Bolded EDWCs are recommended exposure values for surface water sources for human health risk assessment

4

= Ground application. Exposure from grou nd application of trifluralin is compared with aerial application for the

highest exposure scenario ( LA Sugarcane STD ) for sugarcane at 4.0

. lbs/ a.i./ A

. 5

= Groundwater EDWC can be used for acute, chronic and cancer chronic concerns



### Drinking Water Exposure Modeling

Estimated drinking water concentrations (EDWCs) were generated using EFED’s

standard suite of models. Based on the proposed trifluralin label s , the oilseed uses being

addressed are summarized in Table 2

. Trifluralin can be applied as foliar spray as well as

granular spray via ground and aerial applications

.

Table 2. Trifluralin proposed use pattern for oilseed

Crop Maximum

Individual

Application Rate

lbs a.i./A Number of

Applications Minimum

Application

Interval

(days) Maximum

Application Rate per

Season

per Label in

lbs a.i./A Ap plication

Method

Cottonseed

Other Oilseed 2.0

1.0 to 1.25 1

1 Not

applicable 2.0

1.0

- 1.25 Foliar and

granular via

Ground/Aerial

### 4 Models

A

. Surface Water Exposure

- PRZM/EXAMS

Pesticide Root Zone Model (PRZM v3.12 .2, May 12, 2005 ) and Exposure Analysis

Modeling System (EXAMS v2.98.04.06, April 25, 2005 ) are simulation models coupled with the

input PE5.pl shell (PE5, PE Version 5.0, November 15, 2006) to generate EDWCs of trif luralin

residues that may occur in surface water used as drinking water. The PRZM model simulates

pesticide movement and transformation on and across the agricultural field resulting from crop

application s . The EXAMS model simulates pesticide loading via runoff, erosion, and spray drift

assuming a standard watershed of 172.8 ha that drains into an adjacent standard drinking water

index reservoir of 5.26 ha, an average depth of 2.74 m. A more detailed descr iption of the index

reservoir watershed can be found in Jones et al

. , 1998. The coupled PRZM/EXAMS model and

users manuals may be downloaded from the U.S. Environmental Protection Agency (EPA)

Wa ter Models web

- page (U.S. EPA, 2010 ). Perce nt Crop Areas (P CA) that account for the

maximum area within a watershed that may be planted with the modeled crop are applied to

concentrations predicted by PRZM/EXAMS

.

Several standard scenarios for oilseed crop group 20 were modeled for aerial application

. Exposure from ground application of trifluralin was also modeled and compared with aerial

application for the highest exposure scenario (LA Sugarcane STD) for sugarcane with 4.0 lbs

a.i. /A. The EDWCs f or ground application are lower than the aerial application. In addition to

the proposed expansion of tolerance to oilseed crop group, this assessment also re

- evaluate s

existing sugarcane use to reflect the highest EDWCs in the previous drinking water assessment

(US EPA, 2003). Application dates were assumed to be the first week of crop emergence based

on crop scenario and label instructions. Since trifluralin can be used on various agricultural and

non

- agricultural settings (U.S. EPA, 1996), t he default PCA of 1.0 was used based on

agricultural and non

- agricultural us es of trifluralin according to PCA guidance ( U.S. EPA, 201 2 ).

Inputs for PRZM/EXAMS are listed in Table 3. Table 1 also provides EDWCs for various

crops. PRZM/EXAMS input parameters and outputs for an example scenario (LA Sugarcane,

Aerial application) are provided in Appendix A.

Table 3 . PRZM/EXAMS Input Parameters for Trifluralin Proposed Uses

Parameter Input Value and Unit Comment Source

Scenario FL Sugarcane STD

LA Sugarcane STD

ND Canola STD

CA Cotton Wirrg STD

MS Co t ton STD

NC Cotton STD All ava ilable scenarios for each

use N/A 1

Maximum Single

Application Rate

lbs a.i./A Sugarcane :

1.0 ( Continental US )

2.0 (Hawaii)

Oilseed

2.0 (cottonseed)

1.25 (other oilseed) Label directions

Maximum application rate for

safflower Proposed labels



### Treflan ® 

### HFP &

Treflan ® 

### TR

- 10

### 5 Table 3 . PRZM/EXAMS Input Parameters for Trifluralin Proposed Uses

Parameter Input Value and Unit Comment Source

Applications per Year Sugarcane : 2

Oilseed: 1 Label directions. Label

specifies rates per season Proposed labels



### Treflan ® 

### HFP &

Treflan ® 

### TR

- 10

Initial Application Date

FL Sugarcane

LA Sugarcane

CA, MS and NC Cottonseed

ND Canola March 1

March 1

May 1

May 1

Application Interval (d ays ) Sugarcane : 180

Oilseed: Not applicable Intervals were selected to

reflect labeled application

patterns. Proposed labels



### Treflan ® 

### HFP &

Treflan ® 

### TR

- 10

Application Method Aerial and Ground Label directions Proposed labels

CAM 4 Soil Incorporation: 2 inches Proposed l abel s &

Input Guidance 3

Hydrolysis (t 1/2 ) 0 stable MRID 00131100

Spray drift and application

efficiency Aerial: 0.16

Ground: 0.064 Efficiency

– aerial: 0.95,

Ground 0.99 Input Guidance 2

Aerobic soil metabolism (t 1/2 ) 219 days No major degradate formed

in aerobic soil metabolism

study. Upper 90 th %

- ile

confidence bound on the

mean of three half

- lives Input Guidance 2

Aerobic aquatic metabolism

(t 1/2 ) 438 days 2x aerobic soil metabolism Input Guidance 3

Anaerobic aquatic metabolism

(t 1/2 ) 68 In absence of anaerobic

aquatic metabolism data,

soil anaerobic metabolism

data were used. Half

- life

value based on p arent plus

degradate, TR

- 4. Upper 90 th

%

- ile confidence bound on

the mean of three half

- lives MRID 41240502

Aquatic photolysis (t 1/2 ) 9.43 days Half

- life value based on

p arent and degradates, TR

- 6

and TR

- 15 MRID 40560101

Vapor pressure 4.58 ×10

- 5 Torr (mmHg) 6 .1 x 10

- 3 Pa U.S. EPA, 2004C

Solubility in water

(pH 7, 20 °C) 0 .4 mg/ L 3 < 1.0 mg/L. A non

definitive solubility value U.S. EPA, 2004C

Henry’s Law constant (20 °C) 1.03 ×10

- 4 atm.m 3 /mol

--- Toxnet 4

Molecular weight 335.28

--- U.S. EPA, 2004C

Partition coefficient K

oc 8757.9 mL/g Average K

oc ( 6413

, 6748

, 8457 and 13 413 ) MRID 40673501

1 = Not applicable

2

= 3 = US EPA 2010b http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

3 = U.S. National Research Council, 1977

4

= http://toxnet.nlm.nih.gov/

### 6 B . Ground Water Exposure

- SCIGROW

Screening Concentration in Ground Water (SCI

- GROW v2.3, Jul. 29, 2003) is a

regression model used as a screening tool to estimate pesticide concentrations found in ground

water used as drinking water. SCI

- GROW was developed by fitting a linear model to ground

water concentrations with the Relative Index of Leaching Potential (RI LP) as the independent

variable. Ground water concentrations were taken from 90

- day average high concentrations

from Prospective Ground Water studies. The RILP is a function of aerobic soil metabolism and

the soil

- water partition coefficient. The output of SCI

- GROW r epresents the concentrations of

residue s that might be expected in shallow unconfined aquifers under sandy soils, which is

representative of the ground water most vulnerable to pesticide contamination and likely to serve

as a drinking water s ource. The SCI

- GROW user’s manual and i nformation concerning the

model can be found on the EPA Wat er Models web

- page (USEPA, 2010c ). SCIGROW input

parameters are provided in Table 4 and output in Appendix A.

Table 4 . SCI

- GROW Input Parameters for Trifluralin New Uses

Variable Description Input Value

Soil half

- life (day) Use the me an value of 169 days for acceptable aerobic

soil half

- lives ( 189, 201, and days)

Pesticide partition or distribution

coefficients, Koc 8757.9 mL/g (mean value)

Application rate

Sugarcane (H awaii )

Sugarcane (Continental U.S)

Cottonseed

Oilseed crops 2 applications @ 2.0 lb s a.i. / A

2 applications @ 1.0 lb s a.i./ A

1 application @ 2.0. lb s a.i./ A

1 application @1.25

. lb s a.i. / A



### Monitoring Data

The trifluralin TRED provided a comprehensive summary of a number of monitoring

studies. Surface water monitoring data for trifluralin were obtained from the USGS’s National

Water Quality Assessment (NAWQA) program a nd USGS/EPA pilot reservoir monitoring

p rog ram data (Blomquist et al., 2001). Trifluralin detections were generally associated with

watersheds with agricultural use patterns. Trifluralin was detected in 15% of surface water

samples in the NAQWA database

. The highest surface water concentration f rom USGS

NAQWA monitoring program is 1.74 μg/L from the San Joaquin study unit of California.

Trifluralin was also detected in the USGS/EPA pilot reservoir monitoring study at the CA, PA,

LA and SD reservoirs ( Blomquist et al., 2001). Detection frequencie s of trifluralin were low in

both intake (2.8%) and treated (2.2 % ) water. Estimated trifluralin concentrations in both intake

and finished water samples were comparable to the method of detection (MDL) of 0.002 μg/L.

Ground water monitoring data for trifl uralin were obtained from USGS

- NAQWA data.

Trifluralin was detected in 0.5% of ground water samples. The highest groundwater trifluralin

concentration

, 0.15 μg/L

, was detected in Sumter, GA.

### 7 Uncertainties, Limitation and Assumption

• There is no aerobic aquatic degradation data from trifluralin. A default aerobic aquatic

degradation half

- life was estimated as twice the aerobic soil metabolism half

- life.

Submission of aerobic aquatic metabolism data is expected to reduce uncertainties i n the

aquatic metabolism of trifluralin.

• Volatilization of trifluralin was not directly modeled in the PRZM scenario. Because the

aerobic soil metabolism half

- life represents both degradation and volatilization, the soil

metabolism half

- life was used to j ointly describe degradation and volatilization

processes.

• Total toxic residue of trifluralin modeling accounted for only major degradation products

(>10% of the applied) identified in fate studies. The major degradation products were

identified only in aq ueous photolysis and in anaerobic soil metabolism studies. There

were several degradation products identified in aerobic soil metabolism, but none of these

are classified as major or toxic degradation products. The uncertainty in the predicted

EDWCs arises from not including the minor degradation products in the drinking water

exposure assessment.

REFERENCES

Blomquist, J.D., J.M. Denis, J.P. Cowles, J.A. Hetrick, R.D. Jones, and N.R. Birchfield. 2001.

Pesticide in Selected Water Supply Reservoirs and Fin ished Drinking Water, 1999

- 2001.

Summary of Results from Pilot Monitoring Program. USGS open

- File report 01

- 456.

Jones, R. D., S. Abel, W. R. Effland, R. Matzner, R. Parker. 1998. An Index Reservoir for Use

in Assessing Drinking Water Exposure. Proposed Methods for Basin

- scale Estimation of

Pesticide Concentrations in Flowing Water and Reservoirs for Tolerance Reassessment.

Presentation to FIFRA Science Advisory Panel, June 29

- 30, 1998. Online at:

http://www.epa.gov/scipoly/sap/1998/index.htm

U.S. EPA. 2012. Development and Use of Percent Cropped Area and Percent Turf Area

Adjustment Factors in Drinking Water Expo sure Assessments: 2012 Update

. U.S.

Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Office

of Pesticide Programs, Environmental Fate and Effects Division.

http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html

U

. S

. EPA. 2010b . Guidance for Selecting Input Parameters in Modeling the Environmental Fate

and Transport of Pesticides , Version 2.1 . U.S. Environmental Protection Agency, Office of

Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate

and Effects Division, October 22, 2009

. http://www.epa.gov/oppefed1 /models/water/input_parameter_guidance.htm

### 8 US EPA. 2010c . Water Models. U.S. Environmental Protection Agency, Pesticides: Scienc e

and Policy. Online at: http://www.epa.gov/oppefed1/models/water/

U

. S

. EPA. 200 5

. PRZM

- 3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop

Root and Unsaturated Soil Zones: Users Manual for Release 3.0. May 2005

.

U

. S

. EPA. 200 3

. Trifluralin

- Drinking water assessment for tolerance reassessment eligibili ty

decision. (DP 296624). U.S. Environmental Protection Agency, Office of Prevention, Pesticides

and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division,

December 3, 2003

.

U

. S

. EPA. 1996. Reregistration Eligibility Deci sion (RED) Trifluralin. United States Office of

Prevention, Pesticides EPA Environmental Protection And Tox ic Substances April 1996 Agency

(7508W) 738

- R

- 95

- 040.

U.S. GS (Geological Survey). 2012. U.S National Water Quality Assessment Data Warehouse

http://infotrek.er.usgs.gov/apex/f?p=NAWQA:HOME:0



### U.S. National Research Council, 1977. Drinking water and health. Vol. 1. Safe Drinking Water

Committee. National Academy of Sciences, Washington, DC

### 9 A PPENDIX A

PRZM/EXAMS Inputs and Output File

Table 4 Estimated drinking water concentrations (μg/L)



### Scenario Peak 96 hr 21 Day 60 Day 90 Day Yearly Yearly

averages

FL Sugarcane 7.89 5.45 3.01 1.86 1.40 0.74 0.59

LA Sugarcane

(U.S.

Continental) 11.92 8.56 4.06 2.11 1.65 0.99 0.80

LA Sugarcane

(Hawaii) 1 

### 23.83 17.12 8.11 4.22 3.30 1.97 1.59

LA Sugarcane

(Hawaii) 2 

### 19.37 14.27 6.80 3.68 2.87 1. 76 1.35

CA Cotton 12.82 9.18 3.49 1.57 1.20 0.35 0.33

MS Cotton 21.35 15.51 8.30 4.11 3.14 1.08 0.84

NC Cotton 19.63 14.79 7.69 3.88 2.95 0.99 0.88

ND Canola 8.16 5.88 2.74 1.25 0.90 0.30 0.25

1 

### = Aerial Application

2 

### = ground application



### Example of PRZM/EXAMS Output File

stored as HISugrDW.out

Chemical: Trifluralin

PRZM

environm

ent:

LAsugarc

aneSTD.t

xt modified Tueday, 29 May 2007 at 13:56:00

EXAMS

environm

ent:

ir298.exv modified Tueday, 26 August 2008 at 06:14:08

Metfile:

w13970.d

vf modified Tueday, 26 August 2008 at 06:14:50

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 16.86 13.03 7.11 3.58 2.88 1.38

1962 14.03 9.82 6.27 3.43 2.54 1.59

1963 13.50 9.87 3.90 2.33 2.03 1.15

### 10 1964 19.92 15.83 7.03 3.85 2.98 1.86

1965 21.17 14.72 6.99 3.35 2.60 1.48

1966 14.15 11.32 4.56 2.81 2.56 1.43

1967 26.21 18.30 7.22 3.67 3.11 1.63

1968 13.91 10.00 4.06 2.27 1.74 1.18

1969 13.55 9.52 4.92 3.58 2.85 1.66

1970 19.64 13.81 6.61 3.08 2.61 1.56

1971 13.70 9.60 5.23 3.69 2.85 1.60

1972 13.89 10.96 4.68 2.22 2.56 1.52

1973 19.13 13.58 8.16 4.20 3.31 1.98

1974 13.23 9.31 3.50 2.56 2.06 1.18

1975 13.44 9.73 4.85 2.57 2.35 1.51

1976 13.14 9.73 4.02 1.96 1.91 1.31

1977 24.13 17.26 10.38 5.09 3.89 2.04

1978 24.21 17.96 7.66 3.42 2.54 1.57

1979 17.32 13.14 5.49 3.66 3.05 1.67

1980 14.16 9.84 6.29 4.32 3.61 2.07

1981 13.35 9.95 5.34 2.75 2.10 1.42

1982 13.29 9.42 4.30 2.22 1.79 1.41

1983 16.45 12.27 5.44 3.98 3.22 1.85

1984 13.77 9.70 5.99 3.50 3.05 1.52

1985 15.38 10.73 6.37 3.24 2.78 1.59

1986 13.35 9.66 4.17 2.29 2.06 1.54

1987 15.41 11.66 6.08 3.29 2.45 1.67

1988 19.30 13.83 8.43 4.22 3.22 1.91

1989 13.23 9.53 4.42 3.18 2.72 1.93

1990 16.40 11.61 5.27 2.80 2.20 1.56

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.03 26.21 18.30 10.38 5.09 3.89 2.07

0.06 24.21 17.96 8.43 4.32 3.61 2.04

0.10 24.13 17.26 8.16 4.22 3.31 1.98

0.13 21.17 15.83 7.66 4.20 3.22 1.93

0.16 19.92 14.72 7.22 3.98 3.22 1.91

0.19 19.64 13.83 7.11 3.85 3.11 1.86

0.23 19.30 13.81 7.03 3.69 3.05 1.85

0.26 19.13 13.58 6.99 3.67 3.05 1.67

0.29 17.32 13.14 6.61 3.66 2.98 1.67

0.32 16.86 13.03 6.37 3.58 2.88 1.66

0.35 16.45 12.27 6.29 3.58 2.85 1.63

0.39 16.40 11.66 6.27 3.50 2.85 1.60

0.42 15.41 11.61 6.08 3.43 2.78 1.59

0.45 15.38 11.32 5.99 3.42 2.72 1.59

### 11 0.48 14.16 10.96 5.49 3.35 2.61 1.57

0.52 14.15 10.73 5.44 3.29 2.60 1.56

0.55 14.03 10.00 5.34 3.24 2.56 1.56

0.58 13.91 9.95 5.27 3.18 2.56 1.54

0.61 13.89 9.87 5.23 3.08 2.54 1.52

0.65 13.77 9.84 4.92 2.81 2.54 1.52

0.68 13.70 9.82 4.85 2.80 2.45 1.51

0.71 13.55 9.73 4.68 2.75 2.35 1.48

0.74 13.50 9.73 4.56 2.57 2.20 1.43

0.77 13.44 9.70 4.42 2.56 2.10 1.42

0.81 13.35 9.66 4.30 2.33 2.06 1.41

0.84 13.35 9.60 4.17 2.29 2.06 1.38

0.87 13.29 9.53 4.06 2.27 2.03 1.31

0.90 13.23 9.52 4.02 2.22 1.91 1.18

0.94 13.23 9.42 3.90 2.22 1.79 1.18

0.97 13.14 9.31 3.50 1.96 1.74 1.15

0.10 23.83 17.12 8.11 4.22 3.30 1.97

Average

of yearly

averages: 1.59

Inputs generated by pe5.pl

- Novemeber 2006

Data used for this run:

Output File: HISugrDW

Metfile: w13970.dvf

PRZM

scenario: LAsugarcaneSTD.txt

EXAMS

environm

ent file: ir298.exv

Chemical

Name: Triflurali

n

Descripti

on Variable

Name Value Units Comments

Molecula

r weight mwt 335.28 g/mol

Henry's

Law

Const. henry 1.03E

- 04 atm

- m^3/mol

Vapor

Pressure vapr 4.58E

- 05 torr

Solubility sol 0.4 mg/L

Kd Kd mg/L

Koc Koc 8757.9 mg/L

Photolysi

s half

- life kdp 9.43 days Half

- life

Aerobic kbacw 438 days Halfife

### 12 Aquatic

Metabolis

m

Anaerobi

c Aquatic

Metabolis

m kbacs 68 days Halfife

Aerobic

Soil

Metabolis

m asm 219 days Halfife

Hydrolysi

s: pH 7 0 days Half

- life

Method: CAM 4 integer See PRZM manual

Incorpora

tion

Depth: DEPI 5.08 cm

Applicati

on Rate: TAPP 2.24 kg/ha

Applicati

on

Efficienc

y: APPEFF 0.95 fraction

Spray

Drift DRFT 0.16 fraction of application rate applied to pond

Applicati

on Date Date 3

- Jan dd/mm or dd/mmm or dd

- mm or dd

- mmm

Interval 1 interval 180 days Set to 0 or delete line for single app.

app. rate

1 apprate kg/ha

Record

17: FILTRA

IPSCND 1

UPTKF

Record

18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for

Index

Res. Run IR Reservoir

Flag for

runoff

calc. RUNOFF total none, monthly or total(average of entire run)

### 13 Example of SCIGROW Output File

**SCIGROW**

**VERSION 2.3**

**ENVIRONMENTAL FATE AND EFFECTS DIVISION**

**OFFICE OF PESTICIDE PROGRAMS**

**U.S. ENVIRONMENTAL PROTECTION AGENCY**

**SCREENING MODEL**

**FOR AQUATIC PE STICIDE EXPOSURE** 

**SciGrow version 2.3**

**chemical:Trifluralin**

**time is 7/ 3/2012 9:58:50**

**------------------------------------------------------------------------**

**Application Number of Total Use Koc Soil Aerobic**

**rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)** 

**------------------------------------------------------------------------**

**4.000 2.0 8.000 8.76E+03 169.0**

**---------------------------------------------- --------------------------**  **groundwater screening cond (ppb) = 5.49E**

**- 02** 

****************************************************************************

**SciGrow version 2.3**

**chemical:Trifluralin**

**time is 7/ 3/2012 9:58:57**

**------------------------------- -----------------------------------------** 

**Application Number of Total Use Koc Soil Aerobic**

**rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)**

**--------------------------------------------------------------------- ---** 

**2.000 1.0 2.000 8.76E+03 169.0**

**------------------------------------------------------------------------ groundwater screening cond (ppb) = 1.37E** 

**- 02** 

****************************************************************** **************

**SciGrow version 2.3**

**chemical:Trifluralin**

**time is 7/ 3/2012 9:59: 2**

**------------------------------------------------------------------------**

**Application Number of Total Use Koc Soil Aerobic**

**rate (lb/acre) applicat ions (lb/acre/yr) (ml/g) metabolism (days)** 

**------------------------------------------------------------------------**

**1.250 1.0 1.250 8.76E+03 169.0**

**------------------------------------------------------------------ ------**  **groundwater screening cond (ppb) = 8.58E**

**- 03** 

****************************************************************************