1

MEMORANDUM

DATE: April 30, 2013

SUBJECT: Tier I Drinking Water Exposure Assessment for the Section 3 New Use of Boscalid

on Various Agricultural Crops and Homeowner Uses

TO: Steve Funk, Dietary Assessor

Barry O'Keefe, Risk Assessor

Risk Assessment Branch 3

Health Effects Division (7509P)

Heather Garvie, Risk Manager

Robert Westin, Risk Manager

Tony Kish, Product Manager

Cynthia Giles-Parker, Branch Chief

Fungicide Branch

Registration Division, 7505P

FROM: Katrina White, Ph.D. Biologist

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

REVIEWED

BY: James N. Carleton, Ph.D., Senior Scientist

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

APPROVED

BY: Marietta Echeverria, Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

PC Code: 128008

DP Barcode: D409880
2

1. EXECUTIVE SUMMARY

This memo summarizes the Tier I estimated drinking water concentrations (EDWCs) of boscalid

(PC Code 128008, 2-chloro-N-(4'-chlorobiphenyl-2-yl)nicotinamide) in surface water and in 

ground water in support of the proposed Section 3 new use of boscalid for control of a variety 

of fungi on several use sites. A drinking water assessment was recently completed for the 

pending action where the Interregional Research Project Number 4 (IR-4) is seeking registration 

of several new uses (described in Table 2) of boscalid on one supplemental label for Endura® 

Fungicide and four supplemental labels for Pristine® Fungicide (White, 2012, D405064)

(Decision 468292). Additional requests for use on home gardens (Decision 476106) and for use 

by home owners on tomato transplants in greenhouses and lathhouses (Decision 470110) have

recently been submitted. Additionally, the Pesticide Root Zone Model for Groundwater (PRZMGW) model was recently released as a screening level tool for risk assessment purposes in the 

Environmental Fate and Effects Division (EFED) and the registrant does not plan on including 

the cranberry use pattern on the final label. In this document, estimated drinking water 

concentrations (EDWC) for all the proposed new uses are estimated using the PRZM-GW 

model. Surface water EDWCs are based on previous assessments and PRZM/EXAMS. 

This assessment focuses only on the active ingredient boscalid; pyraclostrobin is assessed

separately. The use on turf (0.35 lbs a.i./A, 6 applications, 14 day retreatment interval, ground 

application) results in the highest EDWCs, based on the PRZM-GW model. The previously 

reviewed proposed use on cranberries (1.8 lbs a.i./A/year) that resulted in the highest EDWC 

for surface water will not be included on the final label. 

The EDWCs for both surface and ground water recommended for use in HED’s human health 

dietary risk assessment are summarized in Table 1. The EDWCs resulting from the proposed 

application rates are higher than the EDWCs for surface and ground water in the previous 

drinking water assessments for boscalid (Lieu, 2010, D380018; White, 2012, D405064).

1 The 

EDWCs in surface water are identical to those previously estimated for the turf use which is the 

most conservative scenario now that cranberries is not being considered for registration. The 

EDWCs in ground water are higher than those previously estimated. The reason for the 

differences in EDWCs from previous assessments is the implementation of the PRZM-GW 

model. A Percent Cropped Area (PCA) adjustment factor of 1.0 is assumed for surface water, as 

boscalid has uses on ornamentals, turf, and a variety of agricultural crops. If these EDWC result 

in risk concerns, they can be refined. 

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

conducted some monitoring for boscalid (USGS, 2013). Two surface water samples and four 

sediment samples collected in Georgia were analyzed for boscalid, however the compound was 

 1 Previously estimated surface water concentrations (both acute and annual average) were 426 μg/L for the 

chemical’s use on cranberries (White, 2012, D405064). The previously estimated groundwater concentrations 

were 1.7 μg/L.
3

not detected in these samples (limits of quantitation (LOQ) were 2.8 ng/L in water and 1.7 

μg/kg-sediment) (USGS, 2013).

Two open literature studies are available in which boscalid was monitored. Reilly et al. (2012)

analyzed for boscalid in first-order streams, ponds, and shallow groundwater (< 10 m from the 

surface) draining agricultural areas of the United States with intense fungicide use. Sites were 

chosen based on fungicide use on potatoes. Boscalid was detected in 72% of surface water 

samples, with a maximum detected concentration of 110 ng/L. Boscalid was detected in 62% of 

groundwater samples with a maximum detected concentration of 2120 ng/L. Smalling and 

Orlando (2011) collected water and sediment (both bed and suspended) from January 2008 

through October 2009 from 12 locations within three of the largest watersheds along 

California’s Central Coast (Pajaro, Salinas, and Santa Maria Rivers) and analyzed for a suite of 

pesticides including boscalid. Boscalid was detected in 85% of samples, at a maximum 

concentration of 36 μg/L.

Table 1. Tier I EDWCs for residues of boscalid and unextracted residues based on use on 

turf.

1,2

Source of Drinking 

Water (Model)

Boscalid and unextracted residue concentration in drinking water (μg/L)

Acute Annual Average or Post Breakthrough 

Average

Surface water (FIRST) 97.3 26.4

Groundwater

(PRZM-GW) 773 697

1 These are the highest EDWCs for the proposed and relevant previously evaluated use scenarios. 2 Previously estimated acute and annual average surface water concentrations for turf were 97.3 and 26.4 μg/L, 

respectively. Previously estimated groundwater concentrations were 1.7 μg/L (White, 2012, D405064). The 

previously evaluated use on cranberry, which resulted in the highest EDWC for surface water, will be excluded 

from the final label.

2. PROPOSED USES

The Interregional Research Project Number 4 and BASF are seeking registration of several new 

uses (described in Table 2) of boscalid on one supplemental label for Endura® Fungicide and 

four supplemental labels for Pristine® Fungicide, and one supplemental label for Pageant 

Fungicide. BASF Corporation is also seeking registration of a new homeowner product

containing boscalid. Product formulations, active ingredients, and registration information are 

summarized in Table 3. There are products listed in the table that contain multiple active 

ingredients. This assessment examines potential exposure to boscalid only. Aerial, 

chemigation, ground, and airblast applications are proposed for the agricultural crops. The 

homeowner product may be applied using handheld sprayers. The soluble granules are

dissolved into water and applied as a spray. Two of the proposed uses have not been 

previously assessed in drinking water assessments. These include use in homeowner gardens 
4

and ornamentals2 and use on tomato transplants grown in greenhouses, lathhouses, or 

production structures by homeowners3

. Turf uses historically resulted in the highest EDWCs,

and that use is also included in the Table 2 summary.

The homeowner product label does not provide a maximum single application rate, maximum 

seasonal or annual application rate, or a minimum retreatment interval. This results in 

uncertainty in the potential use of and risk from this product and the ability to enforce 

responsible use of this product. It was determined that it would take approximately three

gallons of 7969-GLG4

, to match use rates on the Pageant label (EPA Registration Number) 7969-

251. The maximum use scenario for agricultural uses was assumed for the homeowner 

product. The pounds a.i. per volume of product was not provided on the label. 

Proposed uses on greenhouses are assumed to be indoor uses. Uses on lathhouses are

considered to be outdoor uses, as lathhouses are open to the environment; however, it is 

assumed that the risk from these uses will be lower than the risks due to the agricultural uses 

as the structures treated may not be commercial structures and the transplants may not be 

used in commercial production. Therefore, small volumes are expected to be used in these use 

scenarios. It is noted that use instructions are uncertain on the Pageant labels. A maximum 

annual application rate on a per acre basis was not provided on the label.

Table 2. Proposed Uses of Boscalid and Registered Use That Previously Resulted in Highest 

EDWC

Use Site

Single App. 

Rate

(lbs. ai/A)a

# of 

App/

cc

Seasonal 

App. 

Rate

(lbs. 

ai/A)

Retreatm

ent 

Interval 

(days)

PHI App. 

Type

Geographic 

Restrictions Comments

Use Historically Resulting in Highest EDWC

Turf 0.35 6 2.1 14 0 G None Emerald fungicide may be 

used on golf course turf only.

Proposed Uses (Not Assessed Previously)

Tomato –

Greenhouse and 

lathhouses

0.36

(Pageant) 3 1.09 7 0 G Not for use in CA

Tomato 

Transplants in 

Structures

0.28

(Pageant) 3

h

1.86 lbs 

a.i./struct

ure/year

7-14 NS H, G

Transplants may not be used 

in commercial production

fields. Homeowner structures 

 2 Uses in residential areas on ornamental trees, shrubs, and flowers were previously assessed in 2007 at a use rate 

of 0.221 lbs a.i./A with a 7 day application interval (Salice and McKinnon, 2007, D342975+). The current proposed 

use on ornamentals only includes instructions of apply until wet and also allows for use on home gardens.

3 Uses in tomato greenhouses have been previously reviewed (Aubee, 2011, D385653+). The current proposed use 

includes use on tomato transplants and grown in lathhouses. 4 Density of product (0.65 g/mL) x Conversion factors (1 lb/453.59237 g) x (3785.4117 mL/gallon) x Percent a.i. in 

product (0.18 lbs boscalid/lb product) = 0.92 lbs boscalid/gallon product. 0.92 lbs boscalid/0.28 lbs boscalid = 3.3 

gallons product
5

Use Site

Single App. 

Rate

(lbs. ai/A)a

# of 

App/

cc

Seasonal 

App. 

Rate

(lbs. 

ai/A)

Retreatm

ent 

Interval 

(days)

PHI App. 

Type

Geographic 

Restrictions Comments

only.

Homeowner 

Garden Spray 

and 

Ornamentals

Spray until 

wet

6 NS NS NS H Prior to disease, Applied using 

hand held sprayer

Proposed Uses – Surface Water Exposure Estimated in November 2012 Drinking Water Assessment

Globe Artichoke 0.29 – 0.36

(Pristine) 3 1.1 7-14 0 NS None

Begin app. at the initiation of 

the protection phase when 

approximately 25% of the 

plants have bolted.

No timing info for Ramularia 

leaf spot.

Persimmon 0.29 – 0.36

(Pristine) 3 1.1 7-14 0 NS None Prior to onset of disease development

Low growing 

berry subgroup 

(excluding

cranberry)g

0.29 – 0.36

(Pristine)

0.35 

(Endura)

5

b,h 1.8 7-14 0 NS None

No later than 10% bloom or 

prior to disease development 

and continue

Root vegetables, 

1B (except sugar 

beets)l

0.13 - 0.16

(Pristine) 6

h 0.95 7-14 0 NS None

Begin applications prior to 

disease development and 

continue.

0.34

(Pristine & 

Endura)

3

b,h 1.03 7-14 0 NS None

0.13 – 0.17

(Pristine) 6

h 1.0 7-14 0 NS None

0.20 

(Endura) 5

b,h 0.99 7-14 0 NS None

Tomato

0.20 – 0.40

(Pristine)

0.15-0.55 

(Endura)

2-5b,o 1.1 7-14 0 NS None Prior to disease development 

and continue

Turnip greens

0.30 – 0.40 

(Pristine)

0.26 – 0.40 

(Endura)

2b,h 0.79 7-14 14 NS None Prior to disease development 

and continue.

On Proposed Label – Uses (or Similar Uses) Assessed Prior to November 2012

Belgium Endive

0.013 –

0.025 lb 

a.i./1000 lbs 

roots

1

0.054 lbs 

a.i. /1000 

lbs roots

See 

Commen

ts

19 Root None

Application made to roots 

when brought into cold 

storage and at the beginning 

of forcing.
6

Use Site

Single App. 

Rate

(lbs. ai/A)a

# of 

App/

cc

Seasonal 

App. 

Rate

(lbs. 

ai/A)

Retreatm

ent 

Interval 

(days)

PHI App. 

Type

Geographic 

Restrictions Comments

0.014-0.028 

lb a.i./70 

square feet 

forcing tray

(Pristine)

1 Root None

Bulb Vegetablesc

0.29

(Pristine) 6b 1.8 14 7 NS Not for use 

in CA

Prior to onset of disease and 

continue

0.30

(Endura) 6

h,b 1.8 7-14 7

Folia

r or 

in 

furro

w 

None

Foliar: Begin applications prior 

to disease development and 

continue

In Furrow: 4-6 inch spray band 

directly over seed furrow 

before covering with soil

Bushberry and 

Caneberry 

Groupsd

0.29 – 0.36 

(Pristine)

0.35

(Endura)

4

b,h

1.5 

(Pristine)

1.4 

(Endura)

7-14 0

Grou

nd 

only

Pristine may 

not be used 

in CA.

Prior to onset of disease and 

continue

Citrus Fruit 

Groupe

0.25 – 0.29

(Pristine) 4

b 1.2 10-21 0 NS None Prior to onset of disease and 

continue

Fruiting 

Vegetablesf

0.15 

(Pristine)

0.11 – 0.15

(Endura)

6

b,o

0.92

(Pristine 

& 

Endura)

5-14 0 NS

Endura may 

not be used 

in CA. 

Prior to onset of disease and 

continue

Rapeseed/

Canolai

0.26

(Pristine)

0.22-0.26 

(Endura)

2h 0.53 7-14 21 NS None

For control of blacklet, apply 

at 2-4 leaf stage. For black 

spot, apply at early pod 

development.

Flax seed

0.26

(Pristine)

0.22-0.26 

(Endura)

2h 0.53 7-14 21 NS None Apply mid-flowering (7-10 

days after flower initiation)

Sunflower

0.39 

(Pristine)

0.20-0.40 

(Endura)

2h

0.77

(Pristine)

0.53 

(Endura)

7-14 21 NS None

Prior to disease development 

and continue...if conditions 

are conducive for disease 

development

Oilseed Cropsj

0.26

(Pristine)

0.22-0.26 

(Endura)

2

b,h 0.53 7-14 21 NS None

Prior to disease development 

and continue...if conditions 

are conducive for disease 

development

Pome Fruit 

Groupsk

0.23 – 0.29

(Pristine)

0.29 

(Endura)

4

h

1.2 

(Pristine)

1.1 

(Endura)

7-14 0 NS

Pristine may 

not be used 

in CA.

Begin applications prior to 

disease development and 

continue.

Small fruit, vine 

climbing 

0.13 – 0.20 

(Pristine) 5h,n 1.1 10-21 14 NS None Prior to onset of disease when conditions favor disease 
7

Use Site

Single App. 

Rate

(lbs. ai/A)a

# of 

App/

cc

Seasonal 

App. 

Rate

(lbs. 

ai/A)

Retreatm

ent 

Interval 

(days)

PHI App. 

Type

Geographic 

Restrictions Comments

subgroup 

(except fuzzy 

kiwifruit)m

0.20 

(Endura)

during early bloom, bunch 

pre-closure and veraison.

0.29 – 0.36 

(Pristine)

0.35 

(Endura)

3

h,n 1.1 14 14 NS None

NS=not specified; G=ground boom application; A=aerial application; H=hand-held sprayer application; cc=crop 

cycle; cc=crop cycle a Application rate calculated for Pristine using 0.0158 lbs a.i./ounce and for Endura using 0.044 lbs a.i./ounce 

(specified on the parent Pristine label dated June 4, 2012 and parent Endura label dated July 12, 2011). 

Application rate for Pageant calculated using 0.0158 lb boscalid per oz. product. b To limit the potential for development of resistance, do not exceed the specified number of applications per 

season of Pristine/Endura or other Group 7 or Group 11 fungicides. c

 Bulb vegetables include chive, daylily, hosta, fritillaria, garlic, kurrat, leek, lily, onion, and shallot.

d Bushberry and Caneberry groups include aronia berry, currant (black, buffalo, native, red), blueberry, Chilean 

guava, elderberry, gooseberry, highbush cranberry, honeysuckle, huckleberry, jostaberry, juneberry, lingonberry, 

salal, blackberry, loganberry, and raspberry.

e The citrus group includes use on lime, calamondin, citron, citrus hybrids, grapefruit, kumquat, lemon, mandarin, 

orange, pummelo, tangelo, tangerine, tangor, uniq fruit, and cultivars and varieties of these.

f Fruiting vegetables include African eggplant, Bush tomato, bell pepper, cocona, currant tomato, eggplant, garden 

huckleberry, goji berry, groundcherry, martynia, naranjilla, okra, pea eggplant, pepino, pepper (all varieties), 

nonbell pepper, roselle, scarlet eggplant, sunberry, tomatillo, and tree tomato. g

The low-growing berry subgroup includes bearberry, bilberry, cloudberry, cranberry, muntries, partridgeberry, 

and strawberry. The registrant decided not to pursue the use on cranberries in this group. h Do not make more than two (some Endura crops specify 3) sequential applications of Pristine/Endura/Pageant

before alternating to a labeled fungicide with a different mode of action.

i Canola varieties only. Endura allows for use on crambe.

j

Crops include borage, calendula, castor oil plant, Chinese tallowtree, crambe, cuphea, echium, euphorbia, evening 

primrose, gold of pleasure, hare’s ear mustard, jojoba, lesquerella, lunaria, meadowfoam, milkweed, mustard 

seed, niger seed, oil radish, poppy seed, rose hip, safflower, sesame, stokes aster, sweet rocket, tallowwood, tea 

oil plant, vernonia.

k

Pome fruits include apple, Asian pear, azarole, crabapple, loquat, mayhaw, medlar, pear, quince, Chinese quince, 

Japanese quince, tejocote.

l

The root vegetables group includes the garden beet, edible burdock, carrot, celeriac, turnip-root chervil, chicory, 

ginseng, horseradish, turnip rooted parsley, parsnip, radish, Oriental radish, rutabega, salsify, black salsify, Spanish

salsify, skirret, and turnip.

m The small fruit, vine climbing subgroup includes amur river grape, goosberry, grapes (except concord, Worden, 

Fredonia, Niagara and related varieties), hardy kiwifruit, maypop, and Schisandra berry.

n To limit the potential for development of resistance, do not make more than five applications of Pristine or other 

Group 7 or Group 11 fungicides per season.

o To limit the potential for development of resistance, do not make more than six applications Endura at the low 

rate or two applications of Endura at the high rate per season.
8

Table 3. Summary of Products Considered in this Assessment

Product Registration 

Number Formulation Active Ingredient (%) Percent a.i. lbs a.i./ oz. of product

Endura® Fungicide 7969-197 WDG Boscalid 70 0.044

Pristine®Fungicide 7969-199 WDG Boscalid 25.2 0.0158

Pyraclostrobin 12.8 0.008

Homeowner Garden 

Spray Fungicide

7969-GLG SC Boscalid 18.0 Not provided

Pyraclostrobin 9.0

Pageant Fungicide 7969-251 WDG Boscalid 25.2 0.008

Pyraclostrobin 12.8 0.0158

WDG=water dispersible granule; SC=suspension concentrate

3. ENVIRONMENTAL FATE AND TRANSPORT SUMMARY

An updated summary of all environmental fate information for boscalid is available in Appendix 

A of the most recently completed drinking water assessment (White, 2012, D405064). Boscalid 

does not dissociate, has a moderate log Kow (2.96), and is considered to be non-volatile from 

dry surfaces, water, and moist soil (White, 2012, D405064). Boscalid is unlikely to 

bioconcentrate in terrestrial or aquatic organisms.

The range of half-lives for boscalid indicates that it is persistent to very persistent.5

 Aerobic 

metabolism in soil is the primary route by which boscalid degrades in the environment, but this 

nevertheless occurs at a very slow rate. Boscalid has been shown in submitted studies to be 

stable to hydrolysis, aqueous photolysis, soil photolysis (1 soil), aerobic aquatic metabolism (2 

pond systems), and anaerobic aquatic metabolism (1 pond system). 

Aerobic soil metabolism half-lives for parent alone (i.e., not including unextracted, unidentified

residues) ranged from 182 to 578 days in four soils (MRID 45643802). One aerobic soil 

metabolism study (MRID 45405208) was conducted on a foreign soil, had only one replicate in 

the study, and was conducted at a higher-than-recommended moisture content (half-life=108 

days); therefore, results from that study were not used in developing model inputs, and are not 

considered to be as reliable as results from other aerobic soil metabolism studies. Aerobic soil 

metabolism half-lives are uncertain, as there were high amounts of unextracted residues 

observed in the studies, and it is not known whether the unextracted residues were residues of 

concern, and/or whether the method of extraction was exhaustive. Therefore, degradation 

rates were estimated for parent alone, as well as for the summed parent plus unextracted 

residues. Half-lives calculated by summing parent and unextracted residues ranged from 848 to 

2553 days in the same five soils. There were one major degradate (2-hydroxy-N-(4’-

chlorobiphenyl-2-yl)nicotinamide))6 and one minor degradate (2-chloronicotinic acid)7

 5 Chemicals with half-lives greater than 60 days in soil, water, and sediment are classified as “persistent” (by EPA’s 

Toxic Release Inventory Program classifications), and chemicals with half-lives greater than 180 days are 

considered “very persistent” (USEPA, 2012). 6 Observed in all five soils.

7 Observed in four of five soils.
9

identified in aerobic soil metabolism studies. These degradates occurred in more than one fate 

study.

Terrestrial field dissipation studies have been conducted at a total of fourteen different sites 

with bare ground applications or applications to bare ground and turf, peach, and almonds. 

Dissipation half-lives ranged from 1 to greater than 360 days, and carryover of residues was 

observed at all 14 sites from one application to the next, and from year to year. Most boscalid 

was observed in the top soil layer, however boscalid was also detected at the deepest depth 

sampled (45 cm) at 3 of 14 sites. The two degradates observed in the aerobic soil metabolism 

studies (2-chloronicotinic acid and 2-hydroxy-N-(4’-chlorobiphenyl-2-yl)nicotinamide) were also 

found in most terrestrial field dissipation studies.

Boscalid is classified as moderately mobile using the FAO classification system. Organic-carbon 

normalized Freundlich distribution coefficients (KFOCs) range from 507 to 1110 (mg/L)(mg/kg)-1/n

measured in six soils (MRID 45405216).8

 Boscalid may be transported to surface water and 

groundwater via runoff, leaching, and spray drift. 

4. RESIDUES OF CONCERN

The Metabolism Assessment Review Committee (MARC) reported that the residue of concern 

for boscalid in drinking water is the parent compound only (Nelson et al., 2003). The 2010 “Tier 

I Drinking Water Assessment for Boscalid used as seed treatment on Rapeseed (cultivars, 

varieties, and/or hybrids, including canola and crambe)” was conducted for boscalid and 

unextracted residues (Lieu, 2010, D380018). The current assessment considers boscalid plus 

unextracted residues, and parent boscalid only, in order to bracket the uncertainty caused by

the presence of high amounts of unextracted residues in fate studies. 

5. MODELING APPROACH AND INPUT PARAMETERS

Most surface water EDWCs and some groundwater EDWCs were determined in previous 

assessments. See Tier I Drinking Water Exposure Assessment for the Section 3 New Use of 

Boscalid on Various Agricultural Crops Including Cranberries (White, 2012, D405064) for a 

discussion of modeling and estimating surface water concentrations. In this assessment, PRZMGW (a newly approved model) was used to estimate groundwater EDWCs, and Tier II modeling 

using PRZM and EXAMS was completed for select scenarios to determine whether Tier II 

modeling would result in higher surface water concentrations than Tier I modeling. The Tier II 

modeling was not previously completed because the cranberry use was expected to be result in 

the highest EDWC. Separate drinking water assessments were not conducted on the proposed

labels for use on homeowner gardens and in greenhouses, lathhouses, and structures grown in

tomato transplants. These uses are assumed to result in exposures similar to or lower than 

previously-generated EDWCs for surface water.

 8 Soil-water distribution coefficients and organic-carbon normalized soil-water distribution coefficients were not 

calculated.
10

1.1 Models

1.1.a. SCI-GROW (Tier I)

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 groundwater 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). 

1.1.b.PRZM-GW (Tier I)

Tier 1 groundwater EDWCs for boscalid were derived with PRZM-GW (Pesticide Root Zone 

Model for Groundwater, version 1.0, August 31, 2012), using the GW-GUI (Graphical User 

Interface, version 1.0, August 31, 2012) (Baris et al., 2013). PRZM-GW is a one-dimensional 

leaching model used to estimate potential concentrations of pesticides in groundwater. The 

model accounts for pesticide fate in the crop root zone by simulating transport and degradation 

occurring throughout the soil profile after a pesticide is applied to an agricultural field. PRZMGW permits the simulation 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 currently available for use with PRZM-GW for risk 

assessment purposes. In the PRZM-GW simulations for this assessment, all of these standard 

scenarios were used. PRZM-GW outputs represent pesticide concentrations in a vulnerable 

groundwater supply located directly beneath an agricultural field. Percent Cropped Area 

adjustment factors (PCAs) are not applied to the results of groundwater modeling, such as 

those generated by either the SCI-GROW or PRZM-GW models.

1.1.a. PRZM/EXAMS (Tier II Surface Water)

Estimated drinking water concentrations (EDWCs) in surface water were generated using 

EFED’s Tier II aquatic models: PRZM (Pesticide Root Zone Model; version. 3.12.3, June 2006) 

(Carsel et al., 1997) and EXAMS (EXposure Analysis Modeling System; Version. 2.98.04.06, April 

2005) (Burns, 2000). Calculations were carried out with the linkage program shell – PE version 

5.0 (November 2006) – which implements the standard crop scenarios developed by EFED

(USEPA, 2006). 

PRZM simulates pesticide fate and transport as a result of leaching, direct spray drift, runoff 

and erosion from an agricultural field, and EXAMS estimates resulting concentrations of 

pesticides in an adjacent surface water body over a 30-year period. The combined models are 

expected to provide high-end estimates of pesticide concentrations that might be found in 

ecologically sensitive aquatic environments following pesticide application. The location of the 

field is specific to the crop being simulated using site-specific information on the soils, weather, 

cropping, and management factors associated with the scenario. The crop/location scenario is 

intended to represent a high-end exposure site on which the crop is normally grown. Based on 
11

historical rainfall data, the receiving water body receives multiple runoff (and possibly spray 

drift) event loadings over the course of the simulated time span. Weather and agricultural 

practices are simulated for 30 year periods (1961 through 1990) so that the 1-in-10-year 

exceedance probability concentration at the site can be estimated. Additional information on 

PRZM and EXAMS can be found at: http://www.epa.gov/oppefed1/models/water/. For drinking 

water exposure assessments, the Index Reservoir (IR) scenario is used in lieu of the standard 

pond scenario. The IR is used in a manner similar to that which the standard pond is used in 

ecological exposure assessments, except that the IR is simulated as a flow-through system, with

a scenario-specific steady flow rate based upon the daily-mean runoff over the duration of a

simulation (a function of local weather conditions). The index reservoir (IR) is approximately 

82-m wide and 640-m long, with an area of 5.3 hectare (USEPA, 1998, 2010). The area of the 

entire watershed is 172.8 ha. Guidance for using the IR is located at: 

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

1.2 Input Parameters

Summaries of the model input parameter values used in SCI-GROW, PRZM-GW, and 

PRZM/EXAMS are presented in Table 4, 5, and 6, respectively. Input parameters were selected 

in accordance with EFED’s “Guidance for Selecting Input Parameters in Modeling the 

Environmental Fate and Transport of Pesticides,” Version 2.1 (USEPA, 2009) and “Guidance for 

Selecting Input Parameters for Modeling Pesticide Concentrations in Groundwater Using the 

Pesticide Root Zone Model,” Version 1 (USEPA and Canada, 2013). 

The standard linear sorption coefficients used in modeling (soil-water distribution coefficients 

and organic-carbon normalized soil-water distribution coefficients) have not previously been 

calculated for boscalid. As this is only a new use assessment, these quantities were not 

calculated for this assessment. Consistent with previous assessments, Freundlich sorption 

coefficients were used in place of linear sorption coefficients to develop model inputs. 

Boscalid’s sorption coefficients have been shown to be nonlinear (Freundlich exponents ranging

from 0.84 to 0.87); however, use of Freundlich coefficients (i.e., KFOC) in place of linear sorption 

coefficients (i.e.,. KOC) is expected to have only minor impact on EDWCs. Coefficients of 

variation (CV) were lower for organic carbon normalized solid-water Freundlich distribution 

coefficients (KFOC; CV=30%) as compared to solid-water Freundlich distribution coefficients (KF; 

CV=88%)(MRID 45405216). Therefore, the mean KFOC (772 (mg/L)(mg/kg)-1/n) was used to 

estimate boscalid concentrations with PRZM-GW and PRZM/EXAMS, and the median KFOC (716 

(mg/L)(mg/kg)-1/n) was used to estimated groundwater concentrations with SCI-GROW. 

The aerobic soil metabolism input value used in PRZM-GW and PRZM/EXAMS was calculated as 

the 90th percentile upper confidence limit on the mean of four half-life values; values were 

separately estimated for parent boscalid alone, and for parent plus unextracted residues

(MRIDs 45643802).

9 The aerobic soil metabolism input value used in SCI-GROW was the 

 9 Values used to calculate the upper 90th percent confidence limit on the mean half-life were 182, 578, 408, and 

289 days for parent only, and 848, 1609, 1000, and 2553 days for parent plus unextracted residues. Aerobic soil 
12

median of the same four half-life values. The uses on agricultural crops allow for ground, aerial,

and airblast applications of a flowable material. For the agricultural crop uses, EDWCs for 

broadcast aerial spray applications were estimated, as aerial applications result in more spray 

drift and therefore higher EDWCs than ground or airblast applications.

Table 4. SCI-GROW (v2.3) Input Parameter Values for Boscalid1

Parameter Value Source Comments

Application Rate (lbs 

a.i./acre) See Table 2 Proposed label See Section titled “Proposed Use” for 

Number of full explanation.

applications Proposed label

K oc (mL/g) 716 MRID 45405216

Median of six KFOC values. There is not 

a three-fold difference in observed 

values. 

Aerobic soil 

metabolism t 1⁄2 (days)

Parent Only: 349

Parent+Unextracted 

Residues: 1305

MRIDs 45643802 Median of four values. There was not a 

five-fold difference in values.

1 Source data are in Appendix A of the 2012 drinking water assessment (White, 2012, D405064).

Table 5. Tier I PRZM-GW Input Parameters

Parameter (units) Input Value Data Source Comments

Application Rate

See Table 7

Labels

--

Number of Applications --

Application Date(s) --

Annual Application Retreatment --

Application Method Above canopy (2)

Soil (1) for in furrow 

--

Date of first Application 

10 days after crop 

emergence

-14 days before 

crop emergence for 

furrow application

--

Assumed

Hydrolysis (half-life (days) Stable (0) MRID 

45405205

Soil Metabolism half-life at 25oC 

(days)

Parent Only: 578

Parent+Unextracted 

Residues: 2454

MRID 

45643802

The 90th percentile upper confidence 

bound on the mean of four half-life 

values. Half-life values adjusted from 

27o

C to 25oC according to input 

parameter guidance.

K oc (L/kg-OC) 772 MRID 

45405216 Mean of six KFOC values. See text.

 

metabolism values were measured at 27oC and were adjusted to 25oC, as recommended for PRZM-GW modeling. 

This was not done for the SCI-GROW modeling. One aerobic soil metabolism study was conducted on a foreign 

soil, included only one replicate, and was conducted at a higher-than-recommended moisture content; therefore, 

results from that study (half-life=108 days) were not included in the development of model inputs (MRID 

45405208).
13

1 Source data are in Appendix A of the 2012 drinking water assessment (White, 2012, D405064).

Table 6. Input Values Used for Boscalid Tier II Surface Water Modeling with PRZM/EXAMs

Parameter (units) Value (s) Source Comments

PRZM Scenario PAturfSTD.txt

FLstrawberryWirrigSTD --

Currently approved standard 

scenarios were used in 

modeling for turf and low 

growing berries, which should 

result in highest EDWC.

EXAMS environment ir298.exv -- Index Reservoir

Field Size Index Reservoir -- --

Runoff Flow Overall -- --

Molecular weight (g/mol) 343.21 -- --

Henry’s Law Constant 

(atm-m3

/mol) 1×10-9 --

Estimated from vapor pressure 

at 25oC and water solubility at 

20o

C.

Vapor Pressure (Torr) at 

25oC 2×10-8 (Mathur, 2002, D285692)

Solubility in Water @ 20 

O

C, pH not reported (mg/L) 4.64 (Mathur, 2002, D285692) −

Organic-carbon 

Normalized Soil-water 

Distribution Coefficient 

(KOC (L/kg-OC ))

772 MRID 45405216, 

45405217

Mean of six KFOC values. See 

text.

CAM (Chemical Application 

Method) 2 (foliar) Proposed Label

Depth of Incorporation 0 Not specified on the label.

Application Rate (kg/ha)

0.39 for turf

0.40 for low growing 

berries

Application efficiency 

(decimal)

0.99 (ground for turf)

0.95 (aerial for berries) Input Guidance. –

Spray drift fraction 

(decimal)

0.01(ground spray)

0.05 (aerial spray) Input Guidance. –

Application date 

(day/month)

01/06 for turf

01/02 for berries --

Determined based on when 

crop was on field and times 

when maximum precipitation 

occurred in that month for 

foliar applications. 

Number of Applications 6 for turf

5 for berries Proposed label --

Minimum retreatment 

interval

14 for turf

7 for berries Proposed label --

IPSCND Foliar: 3 -- --

Hydrolysis Half-life @ pH 4, 

7, 9 (days) Stable (0) MRID 45405205 --

Aqueous Photolysis Halflife @ pH 7 (days) Stable (0) MRID 45405206 --

Water Half-life or Aerobic 

Aquatic Metabolism Halflife (days)Stable (0) MRID 45405214

84% remained at end of study 

with 12-13% unextracted 

residues in two pond systems.
14

Parameter (units) Value (s) Source Comments

Benthic Half-life or 

Anaerobic Aquatic 

Metabolism Half-life (days)

Parent Only: 1155

Parent+Unextracted 

Residues: Stable (0)

MRID 45405213

Parent: single value (385)×3

Parent+Unextracted Residues: 

No significant degradation

Soil Half-life or Aerobic Soil 

Metabolism Half-life (days)

Parent Only: 503

Parent+Unextracted 

Residues: 2136

MRID 45643802

The 90th percentile upper 

confidence bound on the mean 

of four half-life values. Half-life 

values were not adjusted for 

temperature of 27o

C.

Foliar Degradation Rate 0 d-1 Default --

Foliar Washoff Rate 0.5 cm-1 Default -- 1 Source data are in Appendix A of the 2012 drinking water assessment (White, 2012, D405064).

6. MODELING RESULTS

Estimated boscalid concentrations in surface water and ground water used for drinking water 

are summarized in Table 7. Use scenarios evaluated in previous drinking water assessments

that resulted in the highest EDWCs10, and the proposed uses that were not previously 

evaluated were evaluated in this exposure assessment. PRZM-GW predicted the highest 

EDWCs for the use on turf. For use on turf, the maximum single-day concentration of boscalid 

(including unextracted residues) was 773 μg/L, and the associated post-breakthrough average 

concentration was 697 μg/L. The maximum single-day boscalid (including unextracted 

residues) concentration in groundwater for other uses ranged from 297 to 660 μg/L. Postbreakthrough average concentrations for these uses ranged from 268 to 595 μg/L. The 

throughput value was less than one for the Wisconsin Corn, Georgia Peanuts, and Florida 

Potato scenarios using the 30-year weather file. Therefore, the simulation was extended to 

100-years so that a post-breakthrough average could be determined for these scenarios. These 

simulations suggest that it would take several years for boscalid to reach maximum 

concentrations in groundwater. 

Simulated use on turf resulted in the highest EDWC for surface water based on residues of 

boscalid and unextracted residues: 97.33 μg/L for acute and 26.35 μg/L annual average 

concentration. As the model used to generate this result is a Tier I model, this exposure 

estimate can be refined if needed. Acute estimated boscalid plus unextracted residue 

concentrations in surface water used for drinking water for other uses ranged from 39 to 87 

μg/L. Estimated annual average concentrations ranged from 11 to 24 μg/L. Tier I modeling, 

which simulates one year of applications, was used to estimate these surface water 

concentrations and boscalid is very persistent. PRZM and EXAMS modeling simulates 30 years 

of applications and with persistent compounds, EDWCs calculated using Tier II modeling may be 

higher than Tier I EDWCs. Tier II modeling did not result in higher EDWCs for surface water.

 10 The previously evaluated use on cranberries was not included in this assessment because the registrant 

indicated that they were not going to include this use on the final label.
15

Unextracted residues were assumed to consist of parent boscalid in most of the modeling,

though the extent to which unextracted residues are actually comprised of parent boscalid is 

not known. The scenarios that resulted in the highest EDWCs using half-lives based on inclusion 

of unextracted residues were therefore also modeled using half-lives calculated based on

residues of parent only (i.e., assuming that none of the unextracted residues were parent 

compound). These inputs for both parent only and parent plus unextracted residues are shown 

in the Tables 4 and 5. The inclusion of unextracted residues in degradation half-life calculations 

did influence EDWCs for groundwater: residues based on boscalid alone were 55

(423/773=0.55) to 56% (389/697=0.56) of those estimated based on boscalid plus unextracted 

residues.
16

Table 7. Estimated Concentrations of Boscalid and Unextracted Residues in Surface Water and Groundwater Source Drinking Water.

Values with an asterisk were calculated for parent residues only. Values without an asterisk were calculated for parent and unextracted residues.

Use Site

Single 

App. Rate

lbs. ai/Aa

(kg 

a.i./ha)

# of 

App

Ret. 

Int.

days

App. 

Type6

EDWC for parent and unextracted residues in μg/L

EDWC for parent alone in μg/L*

Surface Water Ground Water

SCI-GROW PRZM-GW

Acute Annual 

Average Peak Scenario Highest Daily Peak

Post 

Breakthrough 

Average

Average Simulation 

Breakthrough Time for 

PRZM-GW (Days)

Turf 0.35

(0.39) 6 14 G

97.33

93.56*

26.45∞

26.35

25.36*

0.27∞

1.8

NJ/DE 328 269 6602

FL Citrus 347 335 6528

FL Potato 123 118 16467α

NC 407 370 7292

WI 773

423*

697

389*

13295α

13295*

GA 201 187 13529α

Globe 

Artichoke and 

Persimmon

0.36

(0.40) 3 7

A 52.39 14.68

0.88 WI 396

216*

357

198*

13295α

13295* AB 50.49 13.66

Low growing 

berry subgroup 

(excluding

cranberry)

0.36

(0.40) 5 7

A 87.13

55.78∞

24.42

1.17∞ 1.46 WI 660

360*

595

330*

13295α

13295*

AB 83.95 22.72

Root 

vegetables, 1B 

(except sugar 

beets)

0.16

(0.18) 6 7 A 46.42 13.01 0.78 WI 357 322 13295α

0.34

(0.38) 3 7 A 49.48 13.87 0.83 WI 377 340 13295α

0.17

(0.19) 6 7 A 49.32 13.82 0.83 WI 377 340 13295α

0.20

(0.22) 5 7 A 48.41 13.57 0.81 WI 363 328 13295α

Tomato

0.37

(0.41) 3 7 A 53.88 15.10 0.90 WI 406 366 13295α

0.55 2 7 A 53.44 14.87 0.89 WI 409 369 13295α
17

Use Site

Single 

App. Rate

lbs. ai/Aa

(kg 

a.i./ha)

# of 

App

Ret. 

Int.

days

App. 

Type6

EDWC for parent and unextracted residues in μg/L

EDWC for parent alone in μg/L*

Surface Water Ground Water

SCI-GROW PRZM-GW

Acute Annual 

Average Peak Scenario Highest Daily Peak

Post 

Breakthrough 

Average

Average Simulation 

Breakthrough Time for 

PRZM-GW (Days)

(0.62)

Turnip greens 0.40

(0.45) 2 7 A 38.85 10.89 0.65 WI 297 268 13295α

Abbreviations: App=Application; A=aerial application; AB=airblast application; NJ/DE=Delmarva Sweet Corn; NC=NC cotton; WI=Wisconsin Corn; GA=Georgia 

Peanuts

* Results are for residues of parent alone. All other values reflect residues of boscalid and unextracted residues.

∞ Results determined using PRZM/EXAMS modeling. All other results for surface water results were based on FIRST modeling.

α Simulation was extended to 100-years.
18

7. MONITORING DATA

The following databases and sources were searched on October 29, 2012 for monitoring 

information on boscalid:

• The United States Environmental Protection Agency (USEPA) STORET Database 

(http://www.epa.gov/storet/dbtop.html)

• The USGS National Stream Quality Accounting Network (NASQAN) program 

(http://water.usgs.gov/nasqan/)

No data on boscalid were found in either database.

Some data on boscalid were available in the United States Geological Survey (USGS) National 

Water-Quality Assessment (NAWQA) Program Data Warehouse 

(http://infotrek.er.usgs.gov/traverse/f?p=NAWQA:HOME:1405517206944567), searched on 

October 29, 2012. Boscalid was analyzed in two surface water samples collected in Georgia,

but was not found above the limit of quantitation (LOQ: 2.8 ng/L) in either sample. Four 

bottom material samples collected in Georgia were also analyzed, but boscalid was not 

observed above the LOQ (1.7 μg/kg-sediment) in any of these samples either.

Two studies were found in the open literature, in which boscalid was monitored in surface and 

groundwater. Results from these studies are summarized in Table 8. Reilly et al. (2012)

analyzed for boscalid in first-order streams, ponds, and shallow groundwater (< 10 m from the 

surface) draining agricultural areas of the United States with intense fungicide use. Sites were 

chosen based on fungicide use on potatoes. Twelve surface water and 12 groundwater sites 

were sampled in Maine, Idaho, and Wisconsin for several fungicides and other current use 

pesticides every three weeks from three weeks after the first application to after harvest (7 

sampling events per site). All samples were grab samples collected from the center of flow, or 

vertically integrated from a point within four feet of the water’s edge in the case of a pond 

sample. Shallow groundwater wells were located in the field with samples taken near the 

water table. Sampled surface water watershed areas ranged from 7 to 20,589 hectares. 

Samples were filtered (0.7 μm glass fiber filter) prior to extraction11. Boscalid was detected in 

72% of surface water samples, with a maximum detected concentration of 110 ng/L. Boscalid 

was detected in 62% of groundwater samples with a maximum detected concentration of 2120 

ng/L. The maximum groundwater concentration was 19 fold greater (2120/110) than the 

maximum boscalid concentration detected in surface water. Boscalid was detected in 

groundwater samples the same year in which it was applied in this study. Boscalid may have 

been used in previous years in the area. Boscalid was first registered in 2003 and samples were 

 11 Water samples were extracted onto Oasis HLB solid-phase extraction (SPE) cartridges. Following extraction, SPE 

cartridges were dried, eluted with 12 mL of ethyl acetate, and reduced under nitrogen. Additional extraction steps 

were also completed. 
19

collected in 2009; therefore, boscalid may have been used in the area within five years of 

sampling.

Smalling and Orlando (2011) collected water and sediment (both bed and suspended) from 

January 2008 through October 2009 from 12 locations within three of the largest watersheds 

along California’s Central Coast (Pajaro, Salinas, and Santa Maria Rivers) and analyzed for a 

suite of pesticides including boscalid. Water samples were collected from estuaries and major 

tributaries during four storm events and 11 dry season sampling events between 2008 to 2009. 

The sites included the following station names: Monterrey drainage ditch, Watsonville Slough, 

Pajara River below Thurwatcher, Pajaro River estuary upper, Pajaro river estuary lower, Blanco 

drain, Salinas River at Davis Road, Salinas River estuary upper, Salinas river estuary lower, lower 

Orcutt Creek, Santa Maria River estuary upper, and Santa Maria River estuary lower. Water 

samples were filtered prior to extraction12 (0.7 μm glass fiber filter). Boscalid concentrations 

were generally higher in samples taken during winter storm events than those taken during the 

dry summer season. Boscalid was detected in 85% of samples, at a maximum concentration of 

36 μg/L. Predicted boscalid surface water EDWCs using EFED modeling ranged from 11 to 426 

μg/L. Maximum modeling and monitoring results are within a similar range. It should be noted 

that monitored concentrations are unlikely to represent peak concentrations, particularly given 

that sampling occurred no more frequently than once every 3-4 weeks. Additionally, the use 

and site parameters modeled are different than what occurred at sites where samples were 

collected for monitoring.

Predicted boscalid concentrations in groundwater ranged from 126 to 773 μg/L, while the 

maximum detected concentration in groundwater was 2.12 μg/L (Reilly et al., 2012). 

Groundwater monitoring occurred after just two applications, whereas the boscalid modeling 

results reflect 29-100 years of repeated application. PRZM-GW modeling suggested that the 

time for breakthrough and maximum concentrations to occur was greater than 29-years for 

some scenarios. Monitoring occurred in 2009 and boscalid was first registered in 2003 (i.e., 

boscalid would have only been used in the area within five years of the sample collection). 

Boscalid was detected in the samples in the same year in which it was applied to the field. 

Therefore, the sampled concentrations may not reflect maximum groundwater concentrations 

that may occur if boscalid was used for multiple years. While monitored groundwater 

concentrations were generally lower than monitored surface water concentrations, in the study 

wherein both surface water and groundwater sampling occurred, detected groundwater 

concentrations exceeded surface water concentrations. This result is consistent with what was 

predicted using tier I modeling. Additionally, surface water modeling for boscalid is available 

for more sites than groundwater monitoring. Finally, the use and site parameters modeled are 

different than what occurred at sites where samples were collected for monitoring.

 12 Water samples were extracted by running 1 L of water through an Oasis solid-phase extraction (SPE) cartridge. 

Following extraction, the SPE cartridges were eluted with ethyl acetate. Samples underwent additional processing 

prior to analyzing the extract for residues.
20

Table 8. Summary of boscalid concentrations measured in surface and ground water

Location

Median

Conc.

(ng/L)

Maximum

Conc.

(ng/L)

Frequency of Det. Sampling 

Frequency

Limit 

of Det. 

(ng/L)

Date Source

Surface Water

ID, ME, and 

WI streams 

and pond 

(potato)

22.5 110 72% 3 weeks 0.9-

12.1

2009 -

2012

(Reilly et al., 

2012)

California

Streams and 

Estuaries

74.5

36000

(wet)

639 (dry)

85% 15 samples 

over year

5 2008-

2009

(Smalling 

and Orlando, 

2011)

Groundwater

ID, ME, and 

WI (potato) 21 2120a 62% 3 weeks 0.9-12.1

2009 -

2012

(Reilly et al., 

2012)

Det.=detection or reporting limit; Conc=concentration

a Observed in sample collected at watertable beneath a potato field in Wisconsin 73 days after application. 

Boscalid was applied twice at a rate of 0.178 g/hectare. It was not applied three years prior.

Atmospheric samples were collected in an intensive farming area (Strasbourg, France) in April

and May in 2007 and analyzed for 71 current use pesticides (Schumer et al., 2009). Boscalid 

was detected in 10 of 10 samples at concentrations ranging from 0.35 to 0.81 ng/m3

. The 

average concentration was 0.53 ng/m3

. Boscalid residues were associated with both 

atmospheric particles and the gas phase. These results are summarized in Table 9. 

Table 9. Summary of Air Monitoring Studies for Boscalid (10 samples)

Location

Average 

Concentration

(ng/m3)

Maximum 

Concentration 

(ng/m3)

Frequency 

of 

Detections

Limit of 

Det.

(pg/m3)

Date Source

Strasbourg, 

France 0.53 0.81 100% 27.28 2007 (Schumer et al., 2009)

Det.=detection or reporting limit

8. DRINKING WATER TREATMENT

There is no information available about the effects of drinking water treatment on boscalid. 

The EDWCs in this assessment are representative of concentrations in drinking water source 

water (pre-treatment). For surface water, the conceptual model assumes that a pesticide 

reaches water via spray drift and/or surface runoff, and is instantaneously mixed throughout

the receiving water body. Fate data show that boscalid is stable to hydrolysis. Therefore, 

boscalid will not degrade by hydrolysis during the time that elapses between intake of raw 

water and distribution of treated water to a consumer’s tap. Data also show that boscalid is 

stable to aqueous photolysis; therefore if ultraviolet light were used as a means of disinfection, 

degradation of boscalid would not be expected to occur. Boscalid also does not degrade via 
21

aerobic aquatic metabolism; therefore aerobic metabolism is not expected to be a significant 

loss mechanism for the compound during water treatment either. The most successful drinking 

water treatment process for removal of pesticides from drinking water is generally thought to 

be treatment with granular activated carbon (GAC), which because it is expensive may only be 

used in relatively large drinking water treatment facilities. The ability of GAC to remove organic 

compounds such as pesticides varies with the properties of the chemical, the degree of 

saturation of GAC sorption sites, and the viability of any biofilm that may be present (Badriyha

et al., 2003; Zhao et al., 1999). Data on the sorption of boscalid to GAC are not available; 

however, some loss of boscalid due to sorption is expected if GAC is used in drinking water 

treatment. 

9. UNCERTAINTIES

There are a number of uncertainties associated with this drinking water exposure assessment. 

One source of uncertainty in the assessment is the inclusion of unidentified, unextracted 

residues in the calculation of aerobic soil metabolism half-lives. For the scenarios resulting in 

the highest EDWCs for surface water, inclusion of unextracted residues in half-life calculations

resulted in EDWCs that are almost identical to those estimated for the parent alone (i.e., within 

10 μg/L), therefore this issue represents only a minor source of uncertainty in this assessment. 

On the other hand, peak groundwater concentrations increased from 434 to 773 μg/L when 

unextracted residues were considered to be residues of concern. Chronic concentrations in 

groundwater were also substantially influenced (697 μg/L with unextracted residues versus 389 

μg/L without considering unextracted residues as residues of concern).

There is also uncertainty associated with the use of Tier I models. If dietary risks require 

refinement, higher tiered models and modeling scenarios can be utilized upon request. 

10. LITERATURE CITED

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Ornamentals. D385653+. Environmental Fate and Effects Division. Office of Chemical 

Safety and Pollution Prevention. United States Environmetnal Protection Agency. 

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22

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Surface Water and Sediments from Three Central Califorina Coastal Watersheds, 2008-

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Sediments from Three Central Califorina Coastal Watersheds, 2008-09 (Accessed March 

11, 2013).

USEPA. 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. J.-. Presentation to FIFRA Science Advisory 

Panel, 1998., . 

USEPA. 2006. (P)RZM (E)XAMs Model Shell, Version 5.0. November 15, 2006. Environmental 

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Pollution Prevention. United States Environmental Protection Agency. Available at 
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http://www.epa.gov/oppefed1/models/water/pe5_user_manual.htm (Accessed April 

18, 2013).

USEPA. 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and 

Transport of Pesticides, Version 2.1. Environmental Fate and Effects Division. Office of 

Pesticide Programs. United States Environmental Protection Agency. Available at 

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(Accessed November 12, 2010).

USEPA. 2010. Guidance on Development and Use of the Index Reservoir in Drinking Water 

Exposure Assessments. September 14, 2010. Environmental Fate and Effects Division. 

Office of Pesticide Programs. United States Environmental Protection Agency. Available 

at http://www.epa.gov/oppefed1/models/water/index_reservoir_dwa.pdf (Accessed 

December 9, 2010).

USEPA. 2012. Criteria Used by the PBT Profiler. September 4, 2012. Office of Chemical Safety 

and Pollution Prevention. United States Environmental Protection Agency. Available at 

http://www.pbtprofiler.net/criteria.asp (Accessed September 7, 2012).

USEPA, & Canada, H. 2013. Guidance for Selecting Input Parameters for Modeling Pesticide 

Concentrations in Groundwater Using the Pesticide Root Zone Model. Version 1. 

October 15, 2012. Environmental Fate and Effects Division. Office of Pesticide Programs. 

United States Environmental Protection Agency. Available at 

http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_input_guidanc

e.htm (Accessed February 28, 2013).

USGS. 2013. National Water Quality Assessment Program. United States Geological Survey. 

Available at http://water.usgs.gov/nawqa/ (Accessed April 1, 2013).

White, K. 2012.D405064. Tier I Drinking Water Exposure Assessment for the Section 3 New Use 

of Boscalid on Various Agricultural Crops Including Cranberries. D405064. November 27, 

2012. Environmental Fate and Effects Division. Office of Pesticide Programs. United 

States Environmental Protection Agency. 

Zhao, X., Hickey, R. F., & Voice, T. C. 1999. Long-term evaluation of adsorption capacity in a 

biological activated carbon fluidized bed reactor system. Water Research, 33(13).
24

Appendix A. Modeling Output 

stored as turf.out

Chemical: Boscalid

PRZM environment: PAturfSTD.txt modified Thuday, 23 February 2006 at 

18:55:08

EXAMS environment: ir298.exv modified Thuday, 29 August 2002 at 16:34:12

Metfile: w14751.dvf modified Wedday, 3 July 2002 at 10:06:14

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 8.31 5.66 2.011 1.385 0.9477 0.249

1962 5.743 4.155 1.553 0.6267 0.5823 0.2459

1963 2.278 1.69 0.9052 0.7225 0.5129 0.2406

1964 1.351 1.266 1.232 1.115 0.8282 0.2612

1965 1.701 1.672 1.562 0.7714 0.5227 0.176

1966 26.78 18.65 6.507 2.376 1.683 0.5646

1967 4.636 3.372 1.463 0.8075 0.5571 0.2063

1968 20.45 14.3 4.998 1.812 1.236 0.3344

1969 23.53 15.96 7.581 2.763 1.865 0.5469

1970 1.184 0.8555 0.8438 0.7859 0.5883 0.2175

1971 14.57 10.03 3.945 1.786 1.207 0.346

1972 47.76 33.01 12.22 4.448 3.035 0.8856

1973 21.84 15.22 5.305 1.984 1.371 0.393

1974 5.494 4.225 1.597 1.057 0.7276 0.2181

1975 26.99 19.89 7.947 2.944 1.986 0.5606

1976 7.911 5.797 2.28 1.072 0.7632 0.2639

1977 0.5701 0.4509 0.3881 0.2326 0.1972 0.1108

1978 2.373 1.621 0.9122 0.4185 0.3119 0.1497

1979 4.616 3.239 1.392 0.9426 0.6663 0.3144

1980 4.035 2.952 1.615 1.162 0.8757 0.2358

1981 1.561 1.097 1.057 0.812 0.5818 0.2058

1982 2.68 1.904 0.985 0.4223 0.3006 0.1302

1983 2.16 2.122 1.847 0.6723 0.4905 0.137

1984 1.928 1.899 1.792 1.102 0.7499 0.2475

1985 5.281 3.73 1.39 0.5863 0.4316 0.1878

1986 7.859 5.489 1.957 0.8541 0.5869 0.1949

1987 4.239 3.001 1.906 0.7458 0.5798 0.2163

1988 2.777 1.874 0.6659 0.2697 0.1935 0.08895

1989 5.903 4.085 1.412 0.8759 0.6782 0.2134

1990 3.819 2.655 0.959 0.4522 0.3985 0.1437

Sorted results

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

0.03225806451612947.76 33.01 12.22 4.448 3.035 0.8856

0.0645161290322581 26.99 19.89 7.947 2.944 1.986 0.5646

0.0967741935483871 26.78 18.65 7.581 2.763 1.865 0.5606

0.12903225806451623.53 15.96 6.507 2.376 1.683 0.5469

0.16129032258064521.84 15.22 5.305 1.984 1.371 0.393

0.19354838709677420.45 14.3 4.998 1.812 1.236 0.346

0.22580645161290314.57 10.03 3.945 1.786 1.207 0.3344

0.2580645161290328.31 5.797 2.28 1.385 0.9477 0.3144

0.2903225806451617.911 5.66 2.011 1.162 0.8757 0.2639

0.32258064516129 7.859 5.489 1.957 1.115 0.8282 0.2612
25

0.3548387096774195.903 4.225 1.906 1.102 0.7632 0.249

0.3870967741935485.743 4.155 1.847 1.072 0.7499 0.2475

0.4193548387096775.494 4.085 1.792 1.057 0.7276 0.2459

0.4516129032258065.281 3.73 1.615 0.9426 0.6782 0.2406

0.4838709677419364.636 3.372 1.597 0.8759 0.6663 0.2358

0.5161290322580654.616 3.239 1.562 0.8541 0.5883 0.2181

0.5483870967741944.239 3.001 1.553 0.812 0.5869 0.2175

0.5806451612903234.035 2.952 1.463 0.8075 0.5823 0.2163

0.6129032258064523.819 2.655 1.412 0.7859 0.5818 0.2134

0.6451612903225812.777 2.122 1.392 0.7714 0.5798 0.2063

0.67741935483871 2.68 1.904 1.39 0.7458 0.5571 0.2058

0.7096774193548392.373 1.899 1.232 0.7225 0.5227 0.1949

0.7419354838709682.278 1.874 1.057 0.6723 0.5129 0.1878

0.7741935483870972.16 1.69 0.985 0.6267 0.4905 0.176

0.8064516129032261.928 1.672 0.959 0.5863 0.4316 0.1497

0.8387096774193551.701 1.621 0.9122 0.4522 0.3985 0.1437

0.8709677419354841.561 1.266 0.9052 0.4223 0.3119 0.137

0.9032258064516131.351 1.097 0.8438 0.4185 0.3006 0.1302

0.9354838709677421.184 0.8555 0.6659 0.2697 0.1972

0.1108

0.9677419354838710.5701 0.4509 0.3881 0.2326 0.1935

0.08895

0.1 26.455 18.381 7.4736 2.7243 1.8468 0.55923

Average of yearly averages: 0.276195

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: turf

Metfile: w14751.dvf

PRZM scenario: PAturfSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Boscalid

Description Variable Name Value Units Comments

Molecular weight mwt 343.21 g/mol

Henry's Law Const. henry 1E-3 atm-m^3/mol

Vapor Pressure vapr 2E-8 torr

Solubility sol 4.64 mg/L

Kd Kd mg/L

Koc Koc 772 mg/L

Photolysis half-life kdp 0 days Half-life

Aerobic Aquatic Metabolism kbacw 0 days Halfife

Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 2136 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate:TAPP 0.39 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.01 fraction of application rate applied to pond

Application Date Date 01-06 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 0.39 kg/ha
26

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

app. rate 2 apprate 0.39 kg/ha

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

app. rate 3 apprate 0.39 kg/ha

Interval 4 interval 14 days Set to 0 or delete line for single app.

app. rate 4 apprate 0.39 kg/ha

Interval 5 interval 14 days Set to 0 or delete line for single app.

app. rate 5 apprate 0.39 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)

stored as berri.out

Chemical: Boscalid

PRZM environment: FLstrawberry_WirrigSTD.txt modified Tueday, 29 May 2007 

at 13:53:40

EXAMS environment: ir298.exv modified Thuday, 29 August 2002 at 16:34:12

Metfile: w12842.dvf modified Wedday, 3 July 2002 at 10:04:28

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 16.89 11.3 3.696 2.483 1.996 0.6772

1962 23.05 15.75 9.507 4.291 3.044 0.9478

1963 25.67 18.33 11.05 5.768 3.88 1.245

1964 35.58 23.91 8.054 5.195 4.387 1.475

1965 19.9 14.57 6.215 2.594 1.781 0.8759

1966 29.19 20.8 7.233 3.388 2.327 1.037

1967 12.33 8.759 5.264 3.196 2.316 0.9262

1968 19.4 12.58 4.249 2.556 2.064 0.7465

1969 38.6 26.99 15.32 7.194 5.421 1.785

1970 26.34 17.97 9.485 5.622 3.888 1.224

1971 56.11 36.58 11.51 5.251 3.769 1.345

1972 17.88 11.49 4.802 2.942 2.214 0.9913

1973 54.95 36.74 12.6 4.926 3.6 1.058

1974 35.46 23.02 8.702 4.273 2.9 1.169

1975 16.53 10.67 6.742 3.239 2.371 0.738

1976 46.02 31.85 11.12 4.899 3.776 1.151

1977 7.522 5.531 2.616 1.477 1.08 0.5047

1978 29.82 21.82 10.64 5.222 3.89 1.186

1979 145 97.96 32.92 12.16 11.47 3.11

1980 17.64 11.82 5.45 3.615 2.974 0.9494

1981 35.16 24.35 8.814 4.525 3.112 1.459

1982 17.33 11.74 5.489 3.447 2.568 1.06

1983 30.2 20.69 9.279 7.133 5.406 1.569

1984 24.37 15.92 5.041 2.537 1.803 0.9005

1985 41.61 29.01 10.48 4.89 3.374 1.295

1986 55.87 42.5 14.93 6.112 4.337 1.321

1987 47.42 35.43 14.58 9.332 6.446 1.757
27

1988 23.1 15.75 8.148 3.475 2.552 0.917

1989 17.65 11.97 5.717 2.66 1.815 0.6327

1990 20.97 14.14 7.586 4.037 2.935 1.011

Sorted results

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

0.032258064516129145 97.96 32.92 12.16 11.47 3.11

0.0645161290322581 56.11 42.5 15.32 9.332 6.446 1.785

0.0967741935483871 55.87 36.74 14.93 7.194 5.421 1.757

0.12903225806451654.95 36.58 14.58 7.133 5.406 1.569

0.16129032258064547.42 35.43 12.6 6.112 4.387 1.475

0.19354838709677446.02 31.85 11.51 5.768 4.337 1.459

0.22580645161290341.61 29.01 11.12 5.622 3.89 1.345

0.25806451612903238.6 26.99 11.05 5.251 3.888 1.321

0.29032258064516135.58 24.35 10.64 5.222 3.88 1.295

0.32258064516129 35.46 23.91 10.48 5.195 3.776 1.245

0.35483870967741935.16 23.02 9.507 4.926 3.769 1.224

0.38709677419354830.2 21.82 9.485 4.899 3.6 1.186

0.41935483870967729.82 20.8 9.279 4.89 3.374 1.169

0.45161290322580629.19 20.69 8.814 4.525 3.112 1.151

0.48387096774193626.34 18.33 8.702 4.291 3.044 1.06

0.51612903225806525.67 17.97 8.148 4.273 2.974 1.058

0.54838709677419424.37 15.92 8.054 4.037 2.935 1.037

0.58064516129032323.1 15.75 7.586 3.615 2.9 1.011

0.61290322580645223.05 15.75 7.233 3.475 2.568 0.9913

0.64516129032258120.97 14.57 6.742 3.447 2.552 0.9494

0.67741935483871 19.9 14.14 6.215 3.388 2.371 0.9478

0.70967741935483919.4 12.58 5.717 3.239 2.327 0.9262

0.74193548387096817.88 11.97 5.489 3.196 2.316 0.917

0.77419354838709717.65 11.82 5.45 2.942 2.214 0.9005

0.80645161290322617.64 11.74 5.264 2.66 2.064 0.8759

0.83870967741935517.33 11.49 5.041 2.594 1.996 0.7465

0.87096774193548416.89 11.3 4.802 2.556 1.815 0.738

0.90322580645161316.53 10.67 4.249 2.537 1.803 0.6772

0.93548387096774212.33 8.759 3.696 2.483 1.781 0.6327

0.9677419354838717.522 5.531 2.616 1.477 1.08 0.5047

0.1 55.778 36.724 14.895 7.1879 5.4195 1.7382

Average of yearly averages: 1.16880666666667

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: berri

Metfile: w12842.dvf

PRZM scenario: FLstrawberry_WirrigSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Boscalid

Description Variable Name Value Units Comments

Molecular weight mwt 343.21 g/mol

Henry's Law Const. henry 1E-3 atm-m^3/mol

Vapor Pressure vapr 2E-8 torr

Solubility sol 4.64 mg/L

Kd Kd mg/L
28

Koc Koc 772 mg/L

Photolysis half-life kdp 0 days Half-life

Aerobic Aquatic Metabolism kbacw 0 days Halfife

Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 2136 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate:TAPP 0.40 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.05 fraction of application rate applied to pond

Application Date Date 01-02 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 0.40 kg/ha

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

app. rate 2 apprate 0.40 kg/ha

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

app. rate 3 apprate 0.40 kg/ha

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

app. rate 4 apprate 0.40 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)

stored as pers.out

Chemical: Boscalid

PRZM environment: CAfruit_WirrigSTD.txt modified Tueday, 29 May 2007 at 

13:42:32

EXAMS environment: ir298.exv modified Thuday, 29 August 2002 at 16:34:12

Metfile: w93193.dvf modified Wedday, 3 July 2002 at 10:04:24

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 2.383 1.832 1.059 0.4521 0.304 0.07671

1962 8.975 7.441 3.14 1.387 0.9368 0.236

1963 5.756 4.294 2.495 1.086 0.7531 0.1902

1964 1.088 0.8253 0.5876 0.2515 0.1693 0.04324

1965 4.534 3.304 1.251 0.5788 0.4631 0.1175

1966 1.098 0.8353 0.5944 0.2536 0.1706 0.04711

1967 1.699 1.286 0.8649 0.4045 0.3024 0.08109

1968 1.09 0.8241 0.5859 0.2593 0.1773 0.0447

1969 11.9 8.952 4.313 2.196 1.494 0.3761

1970 3.593 2.68 1.41 0.8145 0.5611 0.1419

1971 1.077 0.8112 0.5775 0.2448 0.1647 0.04783

1972 1.103 0.8385 0.602 0.2653 0.1783 0.04652

1973 4.501 3.33 1.304 0.6981 0.4749 0.1196

1974 1.068 0.8008 0.5703 0.2468 0.1672 0.04216

1975 1.097 0.8325 0.5918 0.2499 0.1683 0.04234
29

1976 7.305 5.453 2.665 1.199 0.8083 0.2031

1977 1.088 0.8215 0.5843 0.245 0.1651 0.0423

1978 6.028 4.935 2.072 1.155 0.7859 0.1982

1979 1.065 0.7959 0.5667 0.2909 0.1962 0.04946

1980 7.119 5.21 2.198 1.208 0.8255 0.2075

1981 3.097 2.505 1.178 0.5059 0.3461 0.08725

1982 1.099 0.8865 0.5889 0.301 0.2847 0.07249

1983 6.329 4.951 3.198 1.408 0.9534 0.2399

1984 1.091 0.8263 0.588 0.2819 0.1897 0.04831

1985 1.118 0.8586 0.6101 0.2823 0.1899 0.04793

1986 5.464 3.968 1.979 0.9792 0.6724 0.1693

1987 1.077 0.809 0.5756 0.3285 0.2301 0.05804

1988 1.074 0.8083 0.5771 0.268 0.1825 0.04829

1989 1.281 0.9226 0.6061 0.3731 0.309 0.07818

1990 1.09 0.8261 0.6011 0.2668 0.1795 0.04592

Sorted results

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

0.03225806451612911.9 8.952 4.313 2.196 1.494 0.3761

0.0645161290322581 8.975 7.441 3.198 1.408 0.9534 0.2399

0.0967741935483871 7.305 5.453 3.14 1.387 0.9368 0.236

0.1290322580645167.119 5.21 2.665 1.208 0.8255 0.2075

0.1612903225806456.329 4.951 2.495 1.199 0.8083 0.2031

0.1935483870967746.028 4.935 2.198 1.155 0.7859 0.1982

0.2258064516129035.756 4.294 2.072 1.086 0.7531 0.1902

0.2580645161290325.464 3.968 1.979 0.9792 0.6724 0.1693

0.2903225806451614.534 3.33 1.41 0.8145 0.5611 0.1419

0.32258064516129 4.501 3.304 1.304 0.6981 0.4749 0.1196

0.3548387096774193.593 2.68 1.251 0.5788 0.4631 0.1175

0.3870967741935483.097 2.505 1.178 0.5059 0.3461 0.08725

0.4193548387096772.383 1.832 1.059 0.4521 0.309 0.08109

0.4516129032258061.699 1.286 0.8649 0.4045 0.304 0.07818

0.4838709677419361.281 0.9226 0.6101 0.3731 0.3024

0.07671

0.5161290322580651.118 0.8865 0.6061 0.3285 0.2847

0.07249

0.5483870967741941.103 0.8586 0.602 0.301 0.2301 0.05804

0.5806451612903231.099 0.8385 0.6011 0.2909 0.1962

0.04946

0.6129032258064521.098 0.8353 0.5944 0.2823 0.1899

0.04831

0.6451612903225811.097 0.8325 0.5918 0.2819 0.1897

0.04829

0.67741935483871 1.091 0.8263 0.5889 0.268 0.1825 0.04793

0.7096774193548391.09 0.8261 0.588 0.2668 0.1795 0.04783

0.7419354838709681.09 0.8253 0.5876 0.2653 0.1783

0.04711

0.7741935483870971.088 0.8241 0.5859 0.2593 0.1773

0.04652

0.8064516129032261.088 0.8215 0.5843 0.2536 0.1706

0.04592

0.8387096774193551.077 0.8112 0.5775 0.2515 0.1693

0.0447

0.8709677419354841.077 0.809 0.5771 0.2499 0.1683 0.04324
30

0.9032258064516131.074 0.8083 0.5756 0.2468 0.1672

0.04234

0.9354838709677421.068 0.8008 0.5703 0.245 0.1651 0.0423

0.9677419354838711.065 0.7959 0.5667 0.2448 0.1647

0.04216

0.1 7.2864 5.4287 3.0925 1.3691 0.92567 0.23315

Average of yearly averages: 0.108305666666667

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: pers

Metfile: w93193.dvf

PRZM scenario: CAfruit_WirrigSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Boscalid

Description Variable Name Value Units Comments

Molecular weight mwt 343.21 g/mol

Henry's Law Const. henry 1E-3 atm-m^3/mol

Vapor Pressure vapr 2E-8 torr

Solubility sol 4.64 mg/L

Kd Kd mg/L

Koc Koc 772 mg/L

Photolysis half-life kdp 0 days Half-life

Aerobic Aquatic Metabolism kbacw 0 days Halfife

Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 2136 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate:TAPP 0.40 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.05 fraction of application rate applied to pond

Application Date Date 16-01 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 0.40 kg/ha

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

app. rate 2 apprate 0.40 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)