### 2 assessment was performed for parent , zoxamide as well as its total toxic residue (TTR; i.e. parent

plus RH

- 150721, RH

- 24549, RH

- 141288 , RH

- 129151 and RH

- 139432 )

, recommend ed by the

Metabolism Assessment Review Committee (MARC) of the Heath Effects Division (US EPA

2000 a; DP 270797 )

. T he s urface water and groundwater modeling was conducted according to

label ed use directions which listed a maximum annual application rate of 1.33 lbs. a.i./A

. Modeling for the foliar application us ed the coupled models PRZM and EXAMS for surface

water and SCI

- GROW for ground water

. For surface water, GA Onion scenario was simulated

for aerial application based on the highest estimated environmental concentrations (EECs)

determined in the recent ecological risk assessment for zoxamide ( US EPA 2013 : DP 411544 ).

In addition, the PRZM

- GW model ( USEPA, 2012 a ) was used in determin ing groundwater

EDWCs for zoxamide and its total toxic residue. Since this is the first time PRZM

- GW modeling

was performed for zoxamide, the highest application rate for all currently registered zoxamide

uses, [ 1.6 lbs a.i/A for use on grape and potato based on the Gavel ® 

### 80WP lab el ( EPA Reg.

No.10163

- 6413) ] was used to determine drinking water exposure in groundwater.

Recommend ed EDWCs for zoxamide and total toxic residue of zoxamide in surface water and

groundwater are summarized in Table 1. For surface water, the EDWCs of zoxa mide for onions,

garlic and shallots (Table 2) did not exceed the recommended peak ( acute ) concentration of

17.55 μg/L, annual mean ( non

- cancer chronic) concentration of 2.49 μg/L

, and the 30 year

annual average concentration (cancer chronic) of 0.91 μg/L for use on grape reported in the

previous drinking water assessment (US EPA, 20 00; DP 266174+ ). Also, t he TTR EDWCs for

onions, garlic and shallots did not exceed the recommended peak ( acute ) concentration of 83.30

μg/L, annual mean ( non

- cancer chron ic) concentration of 54.48 μg/L

, and the 30 year annual

average concentration (cancer chronic) of 22.84 μg/L for use on grape reported in the previous

drinking water assessment (US EPA, 20 00; DP 266174+ ). However, t he previously

recommended EDWCs were base d on 0. 89 PCA ( Percent Cropped Area ) factor and were revised

using the current PCA of 0.91 for agricultural uses according to recently implemented revised

guidance for P CA (USEPA 2012b ).

Table 1

. Recommended EDWCs Based on Parent and Total Toxic Residues of

Zoxamide

Drinking Water

Source Crop Scenario Peak Exposure

(μg/L) Annual Mean

Exposure (μg/L) Average Annual

Exposure (μg/L)

Zoxamide (Parent only)

Surface water NY Grape STD

Scenario 1 17.55 2.49 0.91

Ground water FL Citrus Scenario 2 1.83E

- 03 NA 6.84E

- 04

Total Toxic Residue (Parent +RH

- 150721, RH

- 24549, RH

- 141288, RH

- 129151 and RH

- 139432)

Surface water NY Grape STD

Scenario 1 81.3 54.48 22.84

Ground water WI corn Scenario 2 83.5 NA 65.8

1 Reported EDWCs generated using PRZM/EXAMS model for aerial application (US EPA 2000) and

t hese values are revised with recommended current PCA factor of 0.91.

2 Highest EDWCs generated using PRZM

- GW model based on 1

. 6 0 lbs a.i/A for g rape and potato

[ Gave l 80 WP (EPA Reg. No.10163

- 6413) ]

### 3 The e stimated PZRM

- GW ground water acute concentration of 1.83E

- 03 μg/L for parent and

chronic concentration of 6.84E

- 04 μg/L are lower than the previously recommended

concentration of 6.40E

- 02 μg/L for both acute and chronic values for grape and potato (US EPA,

20 00 ; D 266174+ ). Therefore, the current EDWCs did not supersede the previously

recommended EDWCs for groundwater for zoxamide

. However, PZRM

- GW ground water acute

concentration of 83.5 μg/L and chronic concentration of 65.8 μg/L for TTR are higher than the

previously recommended concentration of 2.07 μg/L for both acute and chronic values for grape and potato (US EPA, 20 00 ; D 266174+ ). Therefore, the current EDWCs supersede the previously

reco mmended EDWCs for groundwater for the total toxic residue of zoxamide.

Table 2

. Maximum EDWCs Based on Parent and Total Toxic Residues of

Zoxamide on onions (Dry Bulb), Garlic and Shallots Uses

Drinking Water

Source Crop Scenario Peak Exposure

(μg/L) Annual Mean

Exposure (μg/L) Average Annual

Exposure (μg/L)

Zoxamide (Parent only)

Surface water GA Onion STD

Scenario 1 6.47 0.47 0. 33

Ground water FL Citrus Scenario 2 1.83E

- 03 NA 6.84E

- 04

Generic Scenario 3 5.15

- E

- 02 5.15

- E

- 02 5.15

- E

- 02

Total Toxic Residue (Parent +RH

- 150721, RH

- 24549, RH

- 141288, RH

- 129151 and RH

- 139432)

Surface water GA Onion STD

Scenario 1 10.09 1.20 0.81

Ground water WI corn Scenario 2 83.5 NA 65.8

Generic Scenario 3 4.52E

- 01 4.52E

- 01 4.52E

- 01

1 PCA of 0.91 adjusted EDWCs generated using PRZM/EXAMS model for aerial application

2 Highest EDWCs generated using PRZM

- GW model based on 1

. 6 0 lbs a.i/A for g rape and potato

[ Gavel 80 WP (EPA Reg. No.10163

- 6413) ]

3 EDWCs generated using SCIGROW model and represent both acute and chronic



### Drinking Water Exposure Modeling

Surface Water

A Tier II drinking water assessment was performed using PRZM (v3.12.2)/EXAMS (v.

2.98.04.06) modeling with the index reservoir scenario. The EDWCs were generated for parent

as well as its total toxic residue (TTR) in which zoxamide and five major degradates, RH

150721, RH

- 24549, RH

- 141288, RH

- 129151, and RH

- 139432 were used for modeling as

recommend ed by the MARC (US EPA 2000). The E DWCs were calculated for the s cenario

yielding the highest EECs ( i.e. , GA onion , aerial application ) for the ecological risk assessment

(US EPA 2013 b ).

T he Pesticide Root Zone Model, (PRZM, Carsel et al . 1997) and the Exposure Analysis

Modeling System (EXAMS, Burns 2000) were used in tandem to generate aquatic EECs. PRZM

(3.12.2 dated May 12, 2005) simulates fate and transport on the agricultural/range land whereas

### 4 EXAMS (2.98.04.06, dated April 25, 200 5) simulates the fate and resulting daily concentrations

in the water body. Simulations are carried out with the linkage program shell, PE5V01.pl (dated

November 15, 2006), which incorporates the standard non

- agricultural scenarios developed by

EFED. The PRZM model simulates pesticide movement and transformation from crop

application through soil residue processes. The EXAMS model simulates pesticide loading via

runoff, erosion, and spray drift assuming a standard watershed of 172.8 ha that drains into a n adjacent standard drinking water index reservoir of 5.26 ha, an average depth of 2.74 m. A more

detailed description of the index reservoir watershed can be found in Jones et al. , 1998. Standard

percent cropped areas (PCA) were used for proposed uses a s estimates of the extent of watershed

on which crops are grown. The default PCA of 0.91 was used for the proposed uses because

currently zoxamide can be used in agricultural settings only (USEPA 2012 b ). Simulations are

run for multiple (usually 30) years, and the E DWCs represent peak values that are expected once

every ten years based on the thirty years of daily values generated during the simulation.

Additional information on these models can be found at:

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

.

This drinking water assessment was performed for TTR ( parent plus RH

- 150721, RH

- 24549,

RH

- 141288, RH

- 129151 and RH

- 139432 )

, recommend ed by the Metabolism Assessment

Review Committee (MARC) of the Heath Effects Division (US EPA 2000a; DP 270797 ). The

percent of degradates related to drinking water concern were incorporated into DT 50s 

### calculations

for fate studies . Estimated DT 50s 

### can be found in Appendix A

. PRZM/EXAMS input

parameters are shown in Table 3 , and EDWCs are provided in Table 2 . Sample output s and

results o f PRZM/EXAMS modeling are provided in Appendix B

.

Table 3 . PRZM/EXAMS Chemical Specific Input Parameters for Zoxamide and Total

Toxic Resi dues of Zoxamide

Parameter Input Value and Unit Source/Comments

Inputs applied for both Parent Zoxamide and Total Toxic Residues (TTR)

Scenario GA Onion Highest EECs observed in the

Ecological Risk Assessment

Number of Application x m aximum

single application rate 7 x 0.17 lbs AI /A (0.19kg ai/ha)

1 x 0.14 lbs ai/A (0.16 kg ai/ha) Gavel ® 75DF Labels

(EPA Est. No. 003125

- FRA

- 001

(EPA Reg. No. 10 163

- 6414 )

Method of application

CAM

= 2 Foliar Spray Product Label as above

Maximum number of applications 8 (Foliar) Product Label as above

Application efficiency 0.95 (Aerial Spray) EFED Model Input Guidance,

Version 2.1 (200 9b ) 1

Spray drift 0. 135 (Aerial Spray) Spray Drift Guidance (20 13 )

Application date and minimum

interval between applications (days) GAOnion wirrigSTD: April 14 (7) A combination of label directions

and information related to crop

profile in current scenario for

PRZM/EXAM model

Molecular Weight 336.1 MRID 44731803

Solubility in water 0.681 mg/L (25 o C) MRID 44731803

Vapor pressure 1.0 x 10

- 7 mm Hg ( 25 o C) MRID 44 7 31803

Henry’s Law constant 3.26 x 10

- 11 atm x m 3 /mol MRID 465159 01

The following input parameters are applicable to parent zoxamide only

### 5 Table 3 . PRZM/EXAMS Chemical Specific Input Parameters for Zoxamide and Total

Toxic Resi dues of Zoxamide

Parameter Input Value and Unit Source/Comments

Hydrolysis 15.5 day @ pH 4.0

15.7 days @ pH 7.0

8.7 days @ pH 9.0 MRID 44731908

Aquatic photolysis t 1/2 (days) 15.7 days MRID 44731911

Aerobic soil metabolism (t 1/2 ) 2 38.7days MRIDs 44 7 31911 and 44 7 31913

Aerobic aquatic metabolism (t 1/2 ) 3 11.8days MRID 4477 0 002

A na erobic aquatic metabolism (t 1/2 ) 4 29.2 days MRID 44731914

Partition coefficient K

oc 1224 mL/g MRID 4473191 6

The following input parameters are applicable to total toxic residues of zoxamide only

Hydrolysis 5 6 6 day @ pH 4.0

661 days @ pH 7.0

114 days @ pH 9.0 MRID 44731908

Aerobic soil metabolism (t 1/2 ) 2 43.5 days MRIDs 4431911 and

- 4431913

Aerobic aquatic metabolism (t 1/2 ) 3 11.8 days MRID 4477002

Anaerobic aquatic metabolism (t 1/2 ) 4 1286 MRID 44731914

Aquatic photolysis t 1/2 (days) 5 268.3 days MRID 44731911

Partition coefficient K

oc 6 131 mL/g 

### EPISUITE

1 Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides

(Version 2.1; Oct. 22, 2009)

2 The 90% of the UCL of the mean metabolism half

- life of all available half

- lives.

3 2 The 90% of the UCL of the mean metabolism half

- life of all available half

- lives. No degradate of drinking water concern was

observed in aerobic aquatic metabolism.

4 2x 14.6 days available anaerobic soil metabolism DT 50

5 Estimated DT 50 of 268.3 days is based on pH 4 hydrolysis DT 50 of 5 6 6 days instead of dark control

6 Used EPISUITE Estimated lowest K

oc of RH

- 139432



### Ground W ater

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. The SCI

- GROW model and user’s manual may also be downloaded from the

EPA Water Models web

- page ( http://www.epa.gov/oppefed1/models/water/#scigrow ). A

summary of the model input parameter values used in the SCI

- GROW m odel is listed in Table 4.

SCI

- GROW EDWCs are presented in Table 2

.

Table. 4. SCI

- GROW Input Parameters for zoxamide and Total Toxic Residue of

Zoxamide

Model Input Variable Input Values Sources Comments

The following input parameters are applicable to parent zoxamide

Application Rate 0.17 lb. a.i./acre (EPA Reg. No.

10 163

- 6414 ) ---

Number of Applications 8 Product Label as

above ---

The following input parameters are applicable to parent zoxamide

### 6 Table. 4. SCI

- GROW Input Parameters for zoxamide and Total Toxic Residue of

Zoxamide

Model Input Variable Input Values Sources Comments

Aerobic Soil Metabolism half

life 40.3 days MRIDs 44 7 31911

and

- 44 7 31913 Mean value

K

oc ( the median value of all

available K

oc s, MRIDs ) 1294 Median value

The following input parameters are applicable to total toxic residues of zoxamide only

Aerobic Soil Metabolism half

life 37.8 days MRIDs 4431911

and

- 44 7 31913 Mean value

K

oc 131 mL/g EPISUITE Lowest Koc derived from

RH

- 139432



### In addition, Tier 1 groundwater EDWCs for zoxamide and its to t al toxic residue , resulting from

its use on grape for its higher application rate of 1. 6 0 lbs a.i./A were estimated using the PRZM

GW model ( USEPA, 2012 c ), with the GW

- GUI (Graphical User Interface, version 1.0, August

31, 2012 a ). PRZM

- GW is a one

- dimensional, finite

- difference model that estimates the

concentrations of pesticides in groundwater. It accounts for pesticide fate in the crop root zone

by simulating pesticide transport and de gradation through the soil profile after a pesticide is

applied to an agricultural field. PRZM

- GW permits the assessment of multiple years of pesticide

application (up to 100 years) on a single site. Six standard scenarios, each representing a

different region known to be vulnerable to groundwater contamination, are available for use with

PRZM

- GW for risk assessment purposes. In PRZM

- GW simulations, each of these standard

scenarios was used. PRZM

- GW output values represent pesticide concentrations in a v ulnerable

groundwater supply that is located directly beneath a rural agricultural field following many

years of pesticide application. B reakthrough s were observed in all modeled scenarios. A

summary of the model input parameter values used in PRZM

- GW m ode l is listed in Table 5

.

PRZM

- GW values are presented in Table 6

. 

### A sample output of PRZM

- GW model can be found in

Appendix B

.

Table 5 . PRZM

- GW Input Parameters 1 

### for Z oxamide and Total Toxic Residue s of

Zoxamide

Variable Name Data Value Data Source

MRID(s) Comment

Application Method Aerial ( Grape and potato ) Current labels EPA Reg# 10163

-
6413

Application Rate

(lbs. a.i./acre) [kg/ha] 0. 2 [0. 224 ] ( Grape and potato) Current labels EPA Reg# 10163

- 6413

Application Frequency Grape and Potato : 8 times/year Current labels EPA Reg# 10163

-
6413

Application Interval (days) 7

- 14 Current labels EPA Reg# 10163

- 6413

The following input parameters are applicable to parent zoxamide

### 7 Table 5 . PRZM

- GW Input Parameters 1 

### for Z oxamide and Total Toxic Residue s of

Zoxamide

Variable Name Data Value Data Source

MRID(s) Comment

Hydrolysis , DT 50 (Days) 15.7 @pH 7.0 MRID 44731908

---

Aerobic Soil Metabolism

DT 50 (Days) 38.7 days MRIDs.:

44 7 31911 and

44 7 31913 The 90% of the upper
confidence limit ( UCL )

of the mean metabolism

half

- life

.

K

oc ( mL/g

oc ) 1224 MRID s:

44731916 Average K

oc

The following input parameters are applicable to total toxic residues of zoxamide

Hydrolysis, DT 50 (Days) 661 @pH 7.0 MRID 44731908

---

Aerobic Soil Metabolism

DT 50 (Days) 43.5 days MRIDs.:

44 7 31911 and

44 7 31913 The 90% of the upper
confidence limit ( UCL )

of the mean metabolism

half

- life

.

K

oc ( mL/g

oc ) 131 EPISUITE Lowest Koc derived

from RH

- 139432

1 EFED input parameter guidance: http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_input_guidance.htm

Table 6 . PRZM

- GW results based on Zoxamide use s on Grape and Oninos, Garlic and Shallots

.

Crop Scenario Highest

Daily

Value ( μ g/L) A verage ( μ g/L) Average S imulation

Breakthrough Time

(days)

Zoxamide (Parent only)

Grape and Potato

( 0

. 2 lbs a.i./ A x 8

applications) D elmarva sweet corn 0.000193 0.000171 10320

FL citrus 0.0022 1 0.00083 1 10243

FL potato 1.21E

- 10 2.25E

- 11 25923

GA peanut 5.74E

- 11 1.42E

- 11 20939

NC cotton 5. 35E

- 08 6.00E

- 09 11089

WI corn 2.32E

- 06 9.03E

- 07

Total Toxic Residue (Parent +RH

- 150721, RH

- 24549, RH

- 141288, RH

- 129151 and RH

- 139432)

Grape and Potato

( 0

. 2 lbs a.i./ A x 8

applications) Delmarva sweet corn 43.2 31.3 1298

FL citrus 58.1 45.8 1308

FL potato 0.71 0.30 3002

GA peanut 7.69 6.64 3117

NC cotton 17.2 11.4 2113

WI corn 83.5 1 65.8 1 2962

1 Bolded values are the highest EDWCs for parent and total toxic residue

.

### 8 Monitoring Data

The U.S. Geological Survey’s National Water Quality Assessment program (NAWQA) has

conducted some monitoring for zoxamide 1



### . Six surface water samples from California and six

sediment samples from Georgia were analyzed for zoxamide. Zoxamide was not detected in any

of the surface water (limit of quantitation (LOQ) was 3.5 ng/L

- water) and sediment (LOQ was

1.1 μg/ K g

- sediment) sample s. However, NAWQA monitoring data were not targeted

specifically to zoxamide use areas or during times of known zoxamide use; thus, the dataset

likely does not reflect peak zoxamide concentrations that may occur in surface waters when

runoff events occur shortly after zoxamide is applied. Zoxamide was not included as an analyte

for groundwater monitoring in the NAWQA program.

Monitoring data for surface water, groundwater, and sediment from the California Department of

Pesticide Regulation (CDPR) were s earched on November 26, 2013 2 

### . Zoxamide monitoring data

were not available.

Uncertainties

The lack of environmental fate data for the major degradates of zoxamide is an uncertainty in

this assessment. To address this uncertainty, Tier II modeling (PRZM /EXAMS) based on the

TTR of zoxamide (zoxamide plus degradation products RH

- 150721, RH

- 24549, RH

- 141288,

RH

- 129151

, and RH

- 139432) was used to determine EDWCs. Although the persistence of the

zoxamide residues was estimated from registrant submitted enviro nmental fate data, the mobility

of zoxamide residues was estimated using the EPISUITE, which is a Windows ®



### - based suite of

physical/chemical property and environmental fate estimation programs developed by the EPA’s

Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC).

Conclusions

This assessment provides estimated drinking water concentrations (EDWCs) of zoxamide and its

major metabolite s, RH

- 150721, RH

- 24549, RH

- 141288, RH

- 129151 and RH

- 139432 in surface

water and groundwater in support of human health risk assessment for use of zoxamide on

onions, shallot and garlic The surface water and groundwater modeling were conducted

according to a label

- recommended maximum annual application rate of 1.33 lbs. a.i./A for foliar

application using the coupled models PRZM and EXAMS for surface water and SCI

- GROW for

ground water. In addition, the PRZM

- GW model was used in determining groundwater EDWCs

for zoxamide and its total toxic residue s

. For surface and groundwater , the EDWCs of zoxamide

and TTR did not exceed the recommended (US EPA 2000b) peak ( acute ), annual mean ( non

cancer chronic) , an d the 30 year annual average concentration s (cancer chronic)

, except in the

PRZM

- GW simulated concentrations for TTR of zoxamide. Recommended acute and chronic

zoxamide TTR concentrations are 83.5 μg/L and 65.8 μg/L for ground water

, respectively.

Zoxamide was not detected in any of the surface water (limit of quantitation (LOQ) was 3.5

ng/L

- water) and sediment (LOQ was 1.1 μg/ K g

- sediment) samples collect ed for NAWQA

. However, NAWQA monitoring data were not targeted specifically to zoxamide use areas or

1 http://water.usgs.gov/nawqa/pnsp /

2 http://www.cdpr.ca.gov/docs/emon/ehap.htm

### 9 during times of known zoxamide use

. Zoxamide was not included as an analyte for groundwater

monitoring in the NAWQA program.

### 10 References

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 Rea ssessment.

Presentation to FIFRA Science Advisory Panel, June 29

- 30, 1998. Online at:

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

US EPA, 2000 a . PP#9F05058; Zoxamide i n/ on Potato and Grapes

. Conclusions of the

11/14/2000 Meeting of the Metabolism Assessment Review Committee. ( D270797)

US EPA, 200 0b

. Estimated Drinking Water Concentrations for zoxamide and its degradation

products December 06 , 200 0 . (D 266174+ )

USEPA. 2009b . 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

.

USEPA. 2010 . Water Models. U.S. Environmental Protection Agency, Pesticides: Scienc e and

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

US EPA . 20 12a. Memorandum: Approval of PRZM

- GW for use of Drinking Water Exposure

Assessment. Environmental Fate and Effects Division, Office of Chemical Safety and

Pollution Prevention. U. S. Environmental Protection Agency.

US EPA

. 20 12b

. Development and Use of Percent Cropped Area and Percent Turf Area

Adjustment Factors in Drinking Water Exposure Assessments: 2012 Update

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

US EPA . 20 13 a . Zoxamide : Ecological Risk Assessment to Support the Proposed New Uses on

Onions (Dry Bulb), Garlic, and Shallots. Environmental Fate and Effects Division, Office

of Chemical Safety and Pollution Prevention. U. S. Environmental Protec tion Agency.

December 12, 2013. (DP 411544)

US EPA . 20 13b. Guidance on Modeling offsite deposition of pesticides via spray drift for

Ecological and Drinking Water Assessments. Environmental Fate and Effects Division,

Office of Chemical Safety and Pollutio n Prevention. U. S. Environmental Protection

Agency. December 20, 2013.

### 11 APPENDIX A

Hydorlysis

### 12 Aquatic Photolysis

### 13 Aerobic Soil Metabolism

Aerobic Aquatic Metabolism

### 14 No degradate of drinking water concern formed in aerobic aquatic metabolism study.

Anaerobic Soil Metabolism

### 15 APPENDIX B

An example output of PRZM/EXAMS modeling

.

stored as GADWTTRA.out

Chemical: Zoxamide TTR

PRZM environment: GAOnion_WirrigSTD.txt

, modified Tueday, 29 May 2007 at 12:54:42

EXAMS environment: pond298.exv

, modified Tueday, 26 August 2008 at 05:14:08

Metfile: w03822.dvf

, modified Tueday, 26 August 2008 at 05:14:10

, Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 8.53 7.77 6.56 5.85 4.49 1.14

1962 4.96 4.60 4.05 3.55 2.76 0.70

1963 9.06 8.22 7.16 4.97 3.80 0.98

1964 12.02 11.18 8.88 5.59 4.04 1.02

1965 6.23 5.60 4.66 3.63 2.84 0.73

1966 8.27 7.80 6.91 4.81 3.71 0.95

1967 6.08 5.50 4.79 3.64 2.80 0.72

1968 7.67 7.04 6.47 4.65 3.57 0.91

1969 21.59 19.69 14.76 8.39 6.19 1.58

1970 8.55 7.77 5.69 3.91 3.03 0.78

1971 6.70 6.11 5.42 4.36 3.28 0.83

1972 6.64 6.07 5.34 4.17 3.25 0.83

1973 5.41 5.05 4.55 3.85 2.96 0.75

1974 13.66 12.30 9.34 6.94 5.40 1.38

1975 7.85 7.27 6.30 5.81 4.36 1.10

1976 10.62 9.88 8.64 7.01 5.23 1.33

1977 4.38 3.96 3.60 3.06 2.29 0.58

1978 5.33 4.82 4.46 3.68 2.79 0.71

1979 8.16 7.53 6.48 5.31 4.02 1.02

1980 6.82 6.20 5.37 3.97 3.06 0.77

1981 4.96 4.55 4.23 3.32 2.48 0.63

1982 7.75 7.21 5.63 4.91 3.76 0.96

1983 7.92 7.39 6.64 4.91 3.63 0.91

1984 9.96 9.03 6.59 5.43 4.08 1.04

1985 5.34 4.68 3.83 3.24 2.54 0.65

1986 4.71 4.25 3.93 3.05 2.31 0.58

1987 11.43 10.30 7.98 5.06 3.79 0.96

1988 6.66 6.06 5.32 4.46 3.35 0.85

1989 4.65 4.23 3.91 3.11 2.34 0.59

1990 6.22 5.76 4.93 3.93 2.94 0.74

### 16 Sorted results

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

0.03 21.59 19.69 14.76 8.39 6.19 1.58

0.06 13.66 12.30 9.34 7.01 5.40 1.38

0.10 12.02 11.18 8.88 6.94 5.23 1.33

0.13 11.43 10.30 8.64 5.85 4.49 1.14

0.16 10.62 9.88 7.98 5.81 4.36 1.10

0.19 9.96 9.03 7.16 5.59 4.08 1.04

0.23 9.06 8.22 6.91 5.43 4.04 1.02

0.26 8.55 7.80 6.64 5.31 4.02 1.02

0.29 8.53 7.77 6.59 5.06 3.80 0.98

0.32 8.27 7.77 6.56 4.97 3.79 0.96

0.35 8.16 7.53 6.48 4.91 3.76 0.96

0.39 7.92 7.39 6.47 4.91 3.71 0.95

0.42 7.85 7.27 6.30 4.81 3.63 0.91

0.45 7.75 7.21 5.69 4.65 3.57 0.91

0.48 7.67 7.04 5.63 4.46 3.35 0.85

0.52 6.82 6.20 5.42 4.36 3.28 0.83

0.55 6.70 6.11 5.37 4.17 3.25 0.83

0.58 6.66 6.07 5.34 3.97 3.06 0.78

0.61 6.64 6.06 5.32 3.93 3.03 0.77

0.65 6.23 5.76 4.93 3.91 2.96 0.75

0.68 6.22 5.60 4.79 3.85 2.94 0.74

0.71 6.08 5.50 4.66 3.68 2.84 0.73

0.74 5.41 5.05 4.55 3.64 2.80 0.72

0.77 5.34 4.82 4.46 3.63 2.79 0.71

0.81 5.33 4.68 4.23 3.55 2.76 0.70

0.84 4.96 4.60 4.05 3.32 2.54 0.65

0.87 4.96 4.55 3.93 3.24 2.48 0.63

0.90 4.71 4.25 3.91 3.11 2.34 0.59

0.94 4.65 4.23 3.83 3.06 2.31 0.58

0.97 4.38 3.96 3.60 3.05 2.29 0.58

0.10 11.96 11.09 8.86 6.83 5.15 1.31

Average

of yearly

averages

: 0.89

Inputs generated by pe5.pl

- Novemeber 2006

Data used for this run:

Output File: GADWTTRA

Metfile: w03822.dvf

### 17 PRZM

scenario: GAOnion_WirrigSTD.txt

EXAMS

environ

ment

file: pond298.exv

Chemica

l Name: Zoxamid

e

Descripti

on Variable

Name Value Units Comments

Molecul

ar

weight mwt 336.1 g/mol

Henry's

Law

Const. henry 3.26E

- 11 atm

- m^3/mol

Vapor

Pressure vapr 1.00E

- 07 torr

Solubilit

y sol 0.681 mg/L

Kd Kd mg/L

Koc Koc 14.3 mg/L

Photolys

is half

life kdp 268.3 days Half

- life

Aerobic

Aquatic

Metaboli

sm kbacw 11.8 days Halfife

Anaerob

ic

Aquatic

Metaboli

sm kbacs 1286 days Halfife

Aerobic

Soil

Metaboli

sm asm 43.5 days Halfife

Hydrolys

is: pH 4 566 days Half

- life

Hydrolys

is: pH 7 661 days Half

- life

Hydrolys

is: pH 9 114 days Half

- life

Method: CAM 2 integer See PRZM manual

Incorpor

ation

Depth: DEPI cm

### 18 Applicati

on Rate: TAPP 0.19 kg/ha

Applicati

on

Efficienc

y: APPEFF 0.95 fraction

Spray

Drift DRFT 0.135 fraction of application rate applied to pond

Applicati

on Date Date 14

- 04 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.

app. rate

1 apprate 0.19 kg/ha

Interval

2 interval 7 days Set to 0 or delete line for single app.

app. rate

2 apprate 0.19 kg/ha

Interval

3 interval 7 days Set to 0 or delete line for single app.

app. rate

3 apprate 0.19 kg/ha

Interval

4 interval 7 days Set to 0 or delete line for single app.

app. rate

4 apprate 0.19 kg/ha

Interval

5 interval 7 days Set to 0 or delete line for single app.

app. rate

5 apprate 0.19 kg/ha

Interval

6 interval 7 days Set to 0 or delete line for single app.

app. rate

6 apprate 0.19 kg/ha

Interval

7 interval 7 days Set to 0 or delete line for single app.

app. rate

7 apprate 0.16 kg/ha

Record

17: FILTRA

IPSCND 1

UPTKF

Record

18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for IR EPA

### 19 Index

Res. Run Pond

Flag for

runoff

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



### I nput and output of SCIGROW modeling

.

**SciGrow version 2.3**

**chemical: Zoxamide** 

**time is 1/ 3/2014 9:37: 6**

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

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

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

**0.170 8.0 1.360 1.29E+03 37.8**

**------------------------------------------------------------------------ groundwater screening cond (ppb) = 5.**  **15E**

**- 02** 

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

**SciGrow version 2.3**

**chemical:Zoxamide**

**time is 1/ 3/2014 9:39:23**

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

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

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

**0.170 8.0 1.360 1.31E+02 40.3**

**------------------------------------------------------------------------ groundwater screening cond (ppb) = 4.52E** 

**- 01** 

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

### 20 Example Output of PRZM

- GW modeling