Page 1 of 13

 

U. S. ENVIRONMENTAL PROTECTION AGENCY

Washington, D.C. 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

PC Code: 120603

DP Barcode: 380619

381445

October 12, 2010 

 

MEMORANDUM

SUBJECT: Tier II Drinking Water Exposure Assessment to Establish Tolerances of 

Tetraconazole on Small Fruit Vine Climbing Subgroup 13-07F, Low Growing 

Berry Subgroup 13-07G and Corn. 

TO: Sidney Jackson, Risk Manager Reviewer

Barbara Madden, Risk Manager

 Lisa Jones, Risk Manager Reviewer

Mary Waller, Risk Manager

FROM: Christopher M. Koper, Chemist

Stephen Wente, Secondary Reviewer

Environmental Fate and Effects Division (7507P)

THROUGH: Nancy Andrews, Branch Chief, Environmental Risk Branch I

Sujatha Sankula, Risk Assessment Process Leader (RAPL), ERB I

Environmental Fate and Effects Division (7507P)

Executive Summary

A Tier II screening-level drinking water assessment was conducted for a petition submitted by

Isagro SpA to establish tolerances of tetraconazole for Small Fruit Vine Climbing Subgroup 13-

07F, Low Growing Berry Subgroup 13-07G and Corn. Two actions have been bundled in this 

assessment: small fruit vine climbing subgroup 13-07F, low growing berry subgroup 13-07G

(D380619) and corn (D381445). It is important to note that cranberry is part of the 13-07G 

subgroup; however, the registrant chose to withdraw cranberry from the label. The letter of 

withdrawal dated 06 October 2010 is located in Appendix C.

Tetraconazole can be applied to fruit and berries by aerial, ground or airblast application in 

addition to chemigation according to MettleTM 125 ME Fungicide (EPA Reg. No. 80289-8) label. 

In addition, the fungicide can be applied to corn by aerial or ground application in addition to 

chemigation according to Domark®230 ME Fungicide (EPA Reg. No. 80289-7) label. The 

estimated drinking water concentrations (EDWCs) are based on the maximum proposed 

application rates specified in the product label. The EDWCs for the human health risk 

assessment are presented in Table 1.
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For surface water, the EDWCs for the crops modeled in this assessment did not exceed the 

previous EDWCs for use on grapes and pecans reported (Table 3, page 5) in the previous 

drinking water assessment (D347085, D350213) dated 01 July 2008. The previously reported 

acute concentration of 10.69 μg/L (GA Pecan – aerial), annual mean (chronic) concentration of 

4.68 μg/L (MN Sugarbeet – aerial) and the highest 30 year annual average concentration of 3.88

μg/L (NC Peanuts – aerial) are higher than the reported EDWCs for various uses in Table 1. 

Therefore, the current EDWCs for surface water do not supersede the drinking water 

concentrations previously estimated for this chemical.

For groundwater, based on the proposed highest annual use rates for low growing berry subgroup 

13-07G (D380619) and corn (D381445), the SCI-GROW model concentrations of tetraconazole

were 0.127 μg/L and 0.0715 μg/L, respectively (Table 1). This value was compared to 0.397

μg/L reported for pecans in the previous drinking water assessment (D347805, D350213) dated 

01 July 2008. Since 0.127 μg/L and 0.0715 μg/L μg/L are less than 0.397 μg/L, the current 

EDWCs do not supersede the previous estimated drinking water concentrations.

In conclusion, the current EDWCs for surface and ground water do not supersede the estimated 

drinking water concentrations previously calculated for tetraconazole.

Table 1. Tetraconazole Estimated Drinking Water Concentrations (EDWCs)1for Surface Water and 

Ground Water based on selected Crop Scenarios

Proposed Label Use

PRZM/EXAMS

Scenario1

(first app date)

Method2

Application Rate

(interval between 

applications)

1-in-10 

year 

acute 

(μg/L)

1-in-10 

year 

chronic 

(μg/L)

30- year 

average 

(μg/L)

Surface Water

MettleTM 125 ME Fungicide

Small Fruit Vine Climbing 

subgroup 13-07F 

(except fuzzy kiwifruit)

CA Grapes

(August 3 – foliar) A

2 app @ 0.04 lb a.i./acre

(14-day interval) 1.32 1.05 0.79

CA Grapes

(August 3 – foliar) G

2 app @ 0.04 lb a.i./acre

(14-day interval) 0.83 0.64 0.48

CA Grapes

(August 3 –airblast) AB 2 app @ 0.04 lb a.i./acre(14-day interval) 0.83 0.64 0.48

CA Grapes

(August 3 – chemigation) C

2 app @ 0.04 lb a.i./acre

(14-day interval) 0.56 0.37 0.27

NY Grapes

(September 17 – foliar) A

2 app @ 0.04 lb a.i./acre

(14-day interval) 3.18 2.21 1.57

NY Grapes

(September 17 – foliar) G

2 app @ 0.04 lb a.i./acre

(14-day interval) 3.06 2.08 1.45

NY Grapes

(September 17 –airblast) AB 2 app @ 0.04 lb a.i./acre(14-day interval) 3.06 2.08 1.45

NY Grapes

(Sept. 17 – chemigation) C

2 app @ 0.04 lb a.i./acre

(14-day interval) 2.93 1.97 1.34

Low Growing Berry 

subgroup 13-07G 

CA Strawberry 3

(May 20 - foliar) A

4 app @ 0.04 lb a.i./acre

(14-day interval) 5.21 3.06 2.43

CA Strawberry

(May 20 - foliar) G

4 app @ 0.04 lb a.i./acre

(14-day interval) 5.20 2.91 2.27

CA Strawberry

(May 20 - airblast) AB 4 app @ 0.04 lb a.i./acre(14-day interval) 5.20 2.91 2.26

CA Strawberry

(May 20 - chemigation) C

4 app @ 0.04 lb a.i./acre

(14-day interval) 5.11 2.76 2.12

FL Strawberry A 4 app @ 0.04 lb a.i./acre 4.22 1.78 1.48
Page 3 of 13

Table 1. Tetraconazole Estimated Drinking Water Concentrations (EDWCs)1for Surface Water and 

Ground Water based on selected Crop Scenarios

Proposed Label Use

PRZM/EXAMS

Scenario1

(first app date)

Method2

Application Rate

(interval between 

applications)

1-in-10 

year 

acute 

(μg/L)

1-in-10 

year 

chronic 

(μg/L)

30- year 

average 

(μg/L)

(January 04 - foliar) (14-day interval)

FL Strawberry

(January 04 - foliar) G

4 app @ 0.04 lb a.i./acre

(14-day interval) 4.28 1.74 1.43

FL Strawberry

(January 04 - airblast) AB 4 app @ 0.04 lb a.i./acre(14-day interval) 4.28 1.74 1.43

FL Strawberry

(January 04 - chemigation) C

4 app @ 0.04 lb a.i./acre

(14-day interval) 4.24 1.69 1.38

OR Berries 3

(June 18 - foliar) A

4 app @ 0.04 lb a.i./acre

(14-day interval) 3.34 2.48 2.02

OR Berries

(June 18 - foliar) G

4 app @ 0.04 lb a.i./acre

(14-day interval) 3.13 2.21 1.78

OR Berries

(June 18 - airblast) AB 4 app @ 0.04 lb a.i./acre(14-day interval) 3.13 2.21 1.77

OR Berries

(June 18 - chemigation) C

4 app @ 0.04 lb a.i./acre

(14-day interval) 2.94 2.01 1.59

Groundwater

SCI-GROW Low Growing Berry 

subgroup 13-07G -- 4 app @ 0.04 lb a.i./acre 0.127 0.127 0.127

Surface Water

Domark®230 ME Fungicide

Corn (field corn and 

popcorn including field 

corn grown for seed)

PA Corn

(July 08 - foliar) A

1 app @ 0.090 lb a.i./acre 3.52 1.73 1.30

PA Corn

(July 08 - foliar) G

1 app @ 0.090 lb a.i./acre 3.45 1.67 1.23

PA Corn

(July 08 -chemigation) C

1 app @ 0.090 lb a.i./acre 3.35 1.61 1.16

PA Corn

(July 01 - foliar) A

2 app @ 0.045 lb a.i./acre

(7-day interval) 3.54 1.74 1.31

PA Corn

(July 01 - foliar) G

2 app @ 0.045 lb a.i./acre

(7-day interval) 3.49 1.68 1.24

PA Corn

(July 01 -chemigation) C

2 app @ 0.045 lb a.i./acre

(7-day interval) 3.39 1.61 1.17

MS Corn

(July 02 - foliar) A

1 app @ 0.090 lb a.i./acre 2.92 1.19 0.93

MS Corn

(July 02 - foliar) G

1 app @ 0.090 lb a.i./acre 2.99 1.18 0.92

MS Corn

(July 02 -chemigation) C

1 app @ 0.090 lb a.i./acre 2.98 1.16 0.90

MS Corn

(June 25 - foliar) A

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.89 1.19 0.93

MS Corn

(June 25 - foliar) G

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.93 1.19 0.92

MS Corn

(June 25 -chemigation) C

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.91 1.17 0.90

IL Corn

(July 23 - foliar) A

1 app @ 0.090 lb a.i./acre 3.01 1.81 1.46

IL Corn

(July 23 - foliar) G

1 app @ 0.090 lb a.i./acre 2.95 1.78 1.41
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Table 1. Tetraconazole Estimated Drinking Water Concentrations (EDWCs)1for Surface Water and 

Ground Water based on selected Crop Scenarios

Proposed Label Use

PRZM/EXAMS

Scenario1

(first app date)

Method2

Application Rate

(interval between 

applications)

1-in-10 

year 

acute 

(μg/L)

1-in-10 

year 

chronic 

(μg/L)

30- year 

average 

(μg/L)

IL Corn

(July 23 -chemigation) C

1 app @ 0.090 lb a.i./acre 2.83 1.73 1.35

IL Corn

(July 16 - foliar) A

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.99 1.82 1.47

IL Corn

(July 16 - foliar) G

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.87 1.78 1.42

IL Corn

(July 16 -chemigation) C

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.76 1.73 1.36

KS Corn

(August 01 - foliar) A

1 app @ 0.090 lb a.i./acre 3.83 1.83 1.45

KS Corn

(August 01 - foliar) G

1 app @ 0.090 lb a.i./acre 3.73 1.82 1.42

KS Corn

(August 01-chemigation) C

1 app @ 0.090 lb a.i./acre 3.65 1.78 1.38

KS Corn

(July 25 - foliar) A

2 app @ 0.045 lb a.i./acre

(7-day interval) 4.06 1.86 1.47

KS Corn

(July 25 - foliar) G

2 app @ 0.045 lb a.i./acre

(7-day interval) 4.00 1.85 1.44

KS Corn

(July 25 -chemigation) C

2 app @ 0.045 lb a.i./acre

(7-day interval) 3.90 1.80 1.40

NC Corn

(July 07 - foliar) A

1 app @ 0.090 lb a.i./acre 2.44 1.35 1.16

NC Corn

(July 07 - foliar) G

1 app @ 0.090 lb a.i./acre 2.29 1.29 1.10

NC Corn

(July 07-chemigation) C

1 app @ 0.090 lb a.i./acre 2.15 1.23 1.04

NC Corn

(June 30 - foliar) A

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.38 1.34 1.17

NC Corn

(June 30 - foliar) G

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.24 1.28 1.10

NC Corn

(June 30 -chemigation) C

2 app @ 0.045 lb a.i./acre

(7-day interval) 2.12 1.22 1.04

Groundwater

SCI-GROW Corn -- 1 app @ 0.090 lb a.i./acre 0.0715 0.0715 0.0715

1 EDWC values adjusted with a Percent Cropped Area (PCA) factor of 0.87. Bold numbers denote maximum EDWC values.

2 A = aerial application, G = ground application, AB = airblast (orchard) application, C = chemigation.

3

It is important to note, two specialty scenarios were employed to properly assess the low growing berry subgroup. 

 CA Strawberry is a Red-Legged Frog (RLF) scenario. OR Berries is an organophosphate (OP) scenario.

Introduction

Tetraconazole is a broad spectrum systemic fungicide with protective, curative, and eradicate 

properties. It is absorbed by the root, stem, and leaves with subsequent translocation to all 

portions of the plant. Tetraconazole is persistent in the environment and does not have a single 

predominant route of dissipation. Based on the field and laboratory studies, tetraconazole is 
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expected to have low volatility from soil and water surfaces and possesses slight mobility in 

soils. Successive applications are expected to result in year-to-year soil accumulation. 

Tetraconazole is likely to reach surface sources of drinking water via spray drift and runoff but 

its tendency to reach ground water is expected to be attenuated due to its lack of mobility in soil. 

The chemical has low potential to reach groundwater, except in soils of high sand and low 

organic matter content. Detailed description of fate and transport properties of tetraconazole can 

be obtained from the comprehensive drinking water assessment (D321622, D321742 and 

D331420) dated 27 November 2006.

Monitoring Data

A typical drinking water treatment operation begins with course filtration of particulate matter 

from a lake or reservoir water intake pipe. Secondary filtration often involves the addition of 

alum or ferric sulfate in order to cause suspended particulate matter to coagulate for easier 

removal of smaller particles in the water column. In addition, lime is also added for pH 

adjustment, softening, and corrosion control. After the raw water has been treated with these 

compounds, it is gently mixed by large mechanical paddles in flocculation basins where the 

suspended particles gather into larger particles and settle to the bottom of settling basins. The 

settled particles form a sludge layer on the bottom of each primary settling basin and the sludge 

is pushed into sumps by traveling mechanical rakes, and is eventually removed from the basins 

through a series of valves and pumps. The clarified water then exits the settling basins, and is 

disinfected by the addition of free chlorine or some other process. Fluorosilicic acid is often 

used to add fluoride to the drinking water to aid in the prevention of dental cavities. The final 

step in the purification process is filtration through a series of sand filters. These filters consist 

of graded gravel topped first with a layer of sand and then with a layer of anthracite. After 

filtration, the purification process is complete, and drinking water is pumped out to customers.

No data were located regarding the fate of tetraconazole during the drinking water process. 

However, since tetraconazole is expected to adsorb to suspended solids and sediment in the 

water column, it may be subject to removal during the filtration process. Furthermore, some 

disinfection processes also employ UV irradiation of the finished water, which may also result in 

the direct photolysis of tetraconazole.

Tetraconazole is not included as one of the analytes monitored in U.S. surface and groundwater 

under the USGS’s National Water Quality Assessment (NAWQA) program. However, the 

Minnesota Department of Agriculture has conducted a surface water monitoring program in 

counties where sugar beets are typically grown to monitor for the presence of various pesticides 

(MRID 46614320). Tetraconazole was not detected (n = 4) in the Buffalo, Chippewa, or Upper 

Minnesota River water sheds, however, it was identified in three out of four samples in the 

Grand Marais Creek watershed at levels below the quantification limit of 0.015 ppb during 

monitoring conducted in 2004. Tetraconazole was not detected in 17 samples obtained in 2003 

or 21 samples obtained in 2004 from the Lower Minnesota River basin. Data from the 2005 

monitoring program indicated that tetraconazole was detected in 7 out of 10 monitored 

watersheds, although only one sample from the Grand Marais Creek watershed had a 

concentration (0.17 ppb) above quantifiable limits (MRID 46890601).

Monitoring data for tetraconazole is infrequent and only available from the Minnesota area 

where it has been applied on sugar beets. The Minnesota Department of Agriculture monitoring 
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was not designed to target tetraconazole high use areas. Hence, the data are not representative of 

worst-case drinking water concentrations and the monitoring data are not recommended to be 

used in the risk assessment. 

Drinking Water Exposure Modeling

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

of models. Two specialty scenarios were employed to properly assess the low growing berry 

subgroup. CA Strawberry is a Red-Legged Frog (RLF) scenario. OR Berries is an 

organophosphate (OP) scenario. In addition, among the 10 possible scenarios for corn, the 

Pennsylvania, Mississippi, Illinois, Kansas and North Carolina corn scenarios were selected to be

geographically representative in this assessment. The proposed uses from the provided label 

were assessed.

Models

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 tetraconazole

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 

applications. 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 description 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) 

Water Models web-page (USEPA, 2010). Percent Crop Areas (PCA) 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.

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 (RILP) 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 represents the concentrations of

residues 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 source. The SCI-GROW user’s manual is currently under development; 

however, information concerning the model can be found on the EPA Water Models web-page 

(USEPA, 2010). 

Input Parameters

Input parameters for the PRZM/EXAMS and SCI-GROW models are listed in Table 2 and

Table 3. Explanations of various model input parameters are discussed below.
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Table 2. PRZM/EXAMS Input Parameters for Tetraconazole 

Input Parameter: Value: Comment: Source:

Scenario(s): Small Fruit Vine Climbing Subgroup 13-07 F: 

CA Grapes, NY Grapes

Low Growing Berry Subgroup 13-07G: 

CA Strawberry, FL Strawberry, OR Berry

Corn:

PA Corn, MS Corn, IL Corn, KS Corn, NC Corn

representative scenarios for 

each use

N/A

Maximum Single 

Application Rate

lbs a.i./acre (kg a.i./ha)

Small Fruit Vine Climbing Subgroup 13-07 F: 

0.04 (0.045)

Low Growing Berry Subgroup 13-07G: 

0.04 (0.045)

Corn:

0.090 (0.101) 1 application

0.045 (0.051) 2 applications

proposed rates proposed label

Applications per Year Small Fruit Vine Climbing Subgroup 13-07 F: 2

Low Growing Berry Subgroup 13-07G: 4

Corn: 1, 2

label directions. Label 

specifies rates per season. If 

crops are rotated with those 

on which tetraconazole is 

used, yearly rates may be 

higher. 

proposed label

Application Interval (days) Small Fruit Vine Climbing Subgroup 13-07 F: 14

Low Growing Berry Subgroup 13-07G: 14

Corn: 7 (2 applications)

proposed application 

intervals

proposed label

Date of Initial Application

(scenario/day/month)

Small Fruit Vine Climbing Subgroup 13-07 F: 

CA Grapes: 03-08

NY Grapes: 17-09

Low Growing Berry Subgroup 13-07G: 

CA Strawberry: 20-05

FL Strawberry: 04-01

OR Berry: 18-06

Corn:

PA Corn: 08-07 (1 app.) and 01-07 (2 app.)

MS Corn: 02-07 (1 app.) and 25-06 (2 app.)

IL Corn: 23-07 (1 app.) and 16-07 (2 app.)

KS Corn: 01-08 (1 app.) and 25-07 (2 app.)

NC Corn: 07-07 (1 app.) and 30-06 (2 app.)

Date of initial application 

was calculated from the PreHarvest Interval (PHI) and 

application interval as 

written on the proposed 

labels. 1For corn, 90 days 

after emergence was 

selected to define corn 

growth stage R3 (brown 

silk/milk).

Crop Scenarios

Application Method Small Fruit Vine Climbing Subgroup 13-07 F: 

Foliar: aerial and ground

Airblast

Chemigation

Low Growing Berry Subgroup 13-07G: 

Foliar: aerial and ground

Airblast

Chemigation

Corn:

Foliar: aerial and ground

Chemigation

label directions proposed label
Page 8 of 13

Table 2. PRZM/EXAMS Input Parameters for Tetraconazole 

Input Parameter: Value: Comment: Source:

CAM Input 2 linear foliar based on crop 

canopy

proposed label

Incorporation Depth (cm.) N/A -- proposed label

IPSCND Input 3 (berries)

1 (corn)

3 = remaining pesticide on 

foliage is retained as surface 

residue and continues to 

undergo decay. 

1 = remaining pesticide on 

foliage is converted to 

surface application to the 

top soil layer 

US EPA, 2005

Spray Drift Fraction 0.16 (aerial)

0.064 (ground)

0.063 (airblast)

0 (chemigation)

See footnote 2 for 

chemigation reference

Input parameter guidance 

(USEPA, 2009) 

Application Efficiency 0.95 (aerial)

0.99 (ground)

0.99 (airblast)

1.0 (chemigation)

-- Input parameter guidance 

(USEPA, 2009)

Molecular Mass (g/mol) 372.1 -- Tomlin, 2003

Vapor Pressure at 25°C 

(torr)

9.901 x 10-7-- MRID 45851801

Henry’s Law Constant

(atm-m

3

/mol)

3.5 x 10-9-- Tomlin, 2003

Solubility in Water (mg/L) 156 pH 7 at 20oC Tomlin, 2003

Organic Carbon Partition 

Coefficient (KOC) (L/kgOC)

4424 3represents the average KOC

from 5 values

MRID 47023201

Aerobic Soil Metabolism 

Half-life (days)

0 (stable) -- MRID 44367005

Aerobic Aquatic 

Metabolism Half-life (days)

447 represents the 90th %-ile 

confidence bound on the 

mean half-life using halflives of 382 and 320 days.

MRID 44751319

Anaerobic Aquatic 

Metabolism Half-life (days)

0 (stable) -- MRID 45840001

Hydrolysis Half-lives (days) 0 (stable) pH 7 MRID 44367002

Aqueous Photolysis

Half-life (days)

215 -- MRID 44367003

N/A = Not Applicable

 

1

= http://www.dekalb-asia.com/pdf/CG5_DifferentStages.pdf

2

= Chemigation (< 1% spray drift as described in http://www.agdrift.com/PDF_FILES/Chem.pdf - modeled as 0%)

3

= The reviewer-calculated coefficients of determination (R2) for the relationships Kads vs. organic matter = 0.94; therefore, the average Koc

 obtained from five values (11491, 2896, 5841, 670, and 1220) was used for this parameter.

Table 3. SCI-GROW Input Parameters for Tetraconazole.

Input Parameter Value Comment Source

Maximum Application Rate per growing 

season (lbs a.i./A)

Low Growing Berry Subgroup 13-07G: 0.04

Corn: 0.09

maximum rates from proposed 

labels

proposed label
Page 9 of 13

Table 3. SCI-GROW Input Parameters for Tetraconazole.

Input Parameter Value Comment Source

Applications per Year 4 (berry)

1 (corn)

label directions proposed label

Organic Carbon Partition Coefficient (KOC) 

(L/kgOC)

670 lowest KOC value because there 

was greater than a three-fold 

variation among five values

MRID 47023201

Aerobic Soil Metabolism

Half-life (days)

1000 1000 days was used since 

tetraconazole was stable over 

the course of 52 weeks in an 

aerobic soil metabolism study

MRID 44367005

Application methods and rates were obtained from the proposed labels for MettleTM 125 ME 

Fungicide (EPA Reg. No. 80289-8) and Domark®230 ME Fungicide (EPA Reg. No. 80289-7). 

Considering corn, 90 days after emergence was selected to define corn growth stage R3 (brown 

silk/milk) as described in the following corn growth and development reference 

http://www.dekalb-asia.com/pdf/CG5_DifferentStages.pdf. 

Standard percent cropped areas (PCA) were used for all uses as estimates of the extent of 

watershed on which crops are grown (Effland et al., 1999). The default agricultural PCA of 0.87 

was used for the proposed uses because they are not confined to specific regions of the United 

States. Actual fractions of cropped areas could be less in some areas of the country. A 

representative PRZM/EXAM model input and output data for CA Strawberry (aerial application) 

is attached in Appendix A. Representative SCI-GROW model input and output data for berries 

and corn are attached in Appendix B.
Page 10 of 13

REFERENCES

Effland, W. R., N. C. Thurman, I. Kennedy. 1999. Proposed Methods for Determining 

Watershed-derived Percent Crop Areas and Considerations for Applying Crop Area 

Adjustments to Surface Water Screening Models. Presentation to the FIFRA Science 

Advisory Panel, May 27, 1999. Online at: 

http://www.epa.gov/scipoly/sap/1999/index.htm

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

Tomlin, C.D.S. 2003. Tetraconazole (CAS No. 112281-77-3). In: The e-Pesticide Manual, 13th 

Edition Version 3.0. Surrey U.K., British Crop Protection Council.

USEPA. 2005. 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.

USEPA. 2009. 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: Science and 

Policy. Online at: http://www.epa.gov/oppefed1/models/water/
Page 11 of 13

Appendix A. Representative PRZM/EXAMS Output: CA Strawberry – Aerial Application

stored as CAstrawberryA.out

Chemical: Tetraconazole

PRZM environment: CAStrawberry-noplasticRLF_V2.txt modified Wedday, 26 March 2008 at 10:39:14

EXAMS environment: ir298.exv modified Tueday, 26 August 2008 at 06:14:07

Metfile: w23234.dvf modified Tueday, 26 August 2008 at 06:15:38

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 2.42 2.26 1.73 0.95 0.69 0.26

1962 7.46 6.88 5.24 3.60 3.17 1.66

1963 4.29 4.10 3.64 3.12 2.98 2.60

1964 4.01 3.89 3.41 2.90 2.75 2.52

1965 4.20 4.06 3.33 2.96 2.80 2.60

1966 4.57 4.45 4.06 3.37 3.05 2.79

1967 6.07 5.86 5.45 4.43 4.16 3.43

1968 4.38 4.24 3.87 3.56 3.47 3.11

1969 4.54 4.45 4.28 4.00 3.80 3.29

1970 5.18 5.02 4.62 3.90 3.72 3.31

1971 3.96 3.88 3.65 3.36 3.29 2.96

1972 4.86 4.70 4.11 3.85 3.54 2.72

1973 4.62 4.45 3.95 3.71 3.53 3.20

1974 4.08 3.98 3.72 3.39 3.31 2.97

1975 3.55 3.51 3.35 3.12 3.04 2.71

1976 4.08 2.96 2.68 2.44 2.37 2.23

1977 4.94 4.67 3.90 3.11 2.92 2.50

1978 4.58 4.43 3.96 3.65 3.49 2.88

1979 4.68 4.48 3.88 3.61 3.44 2.95

1980 4.63 4.48 4.02 3.79 3.70 3.09

1981 4.94 4.74 4.14 3.62 3.27 2.98

1982 7.42 7.01 5.80 4.77 4.45 3.86

1983 5.29 5.16 4.86 4.54 4.45 3.95

1984 4.92 4.74 4.36 3.95 3.81 3.53

1985 3.82 3.75 3.55 3.38 3.36 3.11

1986 4.75 4.57 4.10 3.80 3.59 3.09

1987 3.70 3.60 3.29 3.01 2.95 2.68

1988 3.49 3.37 2.96 2.78 2.66 2.46

1989 3.06 2.98 2.75 2.53 2.47 2.28

1990 2.49 2.45 2.31 2.26 2.20 2.03

Sorted results

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

0.03 7.46 7.01 5.80 4.77 4.45 3.95

0.06 7.42 6.88 5.45 4.54 4.45 3.86

0.10 6.07 5.86 5.24 4.43 4.16 3.53

0.13 5.29 5.16 4.86 4.00 3.81 3.43

0.16 5.18 5.02 4.62 3.95 3.80 3.31

0.19 4.94 4.74 4.36 3.90 3.72 3.29

0.23 4.94 4.74 4.28 3.85 3.70 3.20

0.26 4.92 4.70 4.14 3.80 3.59 3.11

0.29 4.86 4.67 4.11 3.79 3.54 3.11

0.32 4.75 4.57 4.10 3.71 3.53 3.09

0.35 4.68 4.48 4.06 3.65 3.49 3.09

0.39 4.63 4.48 4.02 3.62 3.47 2.98

0.42 4.62 4.45 3.96 3.61 3.44 2.97

0.45 4.58 4.45 3.95 3.60 3.36 2.96

0.48 4.57 4.45 3.90 3.56 3.31 2.95

0.52 4.54 4.43 3.88 3.39 3.29 2.88

0.55 4.38 4.24 3.87 3.38 3.27 2.79

0.58 4.29 4.10 3.72 3.37 3.17 2.72

0.61 4.20 4.06 3.65 3.36 3.05 2.71

0.65 4.08 3.98 3.64 3.12 3.04 2.68

0.68 4.08 3.89 3.55 3.12 2.98 2.60

0.71 4.01 3.88 3.41 3.11 2.95 2.60

0.74 3.96 3.75 3.35 3.01 2.92 2.52

0.77 3.82 3.60 3.33 2.96 2.80 2.50

0.81 3.70 3.51 3.29 2.90 2.75 2.46

0.84 3.55 3.37 2.96 2.78 2.66 2.28

0.87 3.49 2.98 2.75 2.53 2.47 2.23

0.90 3.06 2.96 2.68 2.44 2.37 2.03

0.94 2.49 2.45 2.31 2.26 2.20 1.66

0.97 2.42 2.26 1.73 0.95 0.69 0.26

0.10 5.99 5.79 5.21 4.39 4.12 3.52 3.06

Italics define PCA adjusted values 5.21 Average of yearly averages: 2.79 2.43

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: CAstrawberryA

Metfile: w23234.dvf

PRZM scenario: CAStrawberry-noplasticRLF_V2.txt

EXAMS environment file: ir298.exv

Chemical Name: Tetraconazole

Description Variable NameValue Units Comments

Molecular weight mwt 372.1 g/mol

Henry's Law Const. henry 3.50E-09 atm-m^3/mol

Vapor Pressure vapr 9.90E-07 torr

Solubility sol 156 mg/L

Kd Kd mg/L

Koc Koc 4424 mg/L

Photolysis half-life kdp 215 days Half-life

Aerobic Aquatic Metabolism kbacw 447 days Halfife

Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 0 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI cm

Application Rate: TAPP 0.045 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.16 fraction of application rate applied to pond

Application Date Date 20-05 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

app. rate 1 apprate 0.045 kg/ha

Interval 2 interval 14 days Set to 0 or delete line for single app.

app. rate 2 apprate 0.045 kg/ha

Interval 3 interval 14 days Set to 0 or delete line for single app.

app. rate 3 apprate 0.045 kg/ha

Record 17: FILTRA

IPSCND 3

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)
Page 12 of 13

Appendix B. SCI-GROW Output Files:

SCIGROW

VERSION 2.3

ENVIRONMENTAL FATE AND EFFECTS DIVISION

OFFICE OF PESTICIDE PROGRAMS

U.S. ENVIRONMENTAL PROTECTION AGENCY

SCREENING MODEL

FOR AQUATIC PESTICIDE EXPOSURE

Low Growing Berries:

SciGrow version 2.3

Chemical:Tetraconazole on Low Growing Berries

time is 9/27/2010 17:25:37

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

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

------------------------------------------------------------------------

 0.040 4.0 0.160 6.70E+02 1000.0

------------------------------------------------------------------------

groundwater screening cond (ppb) = 1.27E-01 or 0.127

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

Corn:

SciGrow version 2.3

chemical:Tetraconazole

time is 9/27/2010 17:29:17

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

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

------------------------------------------------------------------------

 0.090 1.0 0.090 6.70E+02 1000.0

------------------------------------------------------------------------

groundwater screening cond (ppb) = 7.15E-02 or 0.0715

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

Appendix C. Letter of Withdrawal for Cranberry
Page 13 of 13