### 1 MEMORANDUM

DATE: April 30, 2013

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

on Various Agricultural Crops and Home owner 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: Ja m es 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: D409 880

### 2 1. EXECUTIVE SUMMARY

This memo summarizes the Tier I estimated drinking water concentrations (EDWC s ) 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 u se of boscalid for control of a variety

of fungi on sev eral use sites

. A drin king water assessment was recently completed for the

pendin g action where t he I nterregional 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 )

. A dditio nal request s for use on home gardens (Decision 476106) and for use

by home owners on tomato transplants in greenhouse s and lathhouses (Decision 470110) ha ve

recently been submitted. Additionally, the Pesticide Root Zone Model for Groundwater ( PRZM

GW ) model was recently released as a screening level tool for risk assessment purposes in the

Environmental Fate and Effects Divis ion (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

- G W

model

. Su rface water EDW C s are based on previous assessments and PRZM/EXAM S

.

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) result s in the highest EDWC s

, based on the PRZM

- GW model . The previously

reviewed p roposed 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 propos ed

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

drinking water assessments for boscalid ( Lieu, 2010, D380018 ; White, 2012, D40506 4 )

. 1 

### The

EDWC s in surface water are i dentical to those previous ly 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. T he reason for the

differences in EDWC s from previous assessments is the implementation of the PRZM

- GW

model

. A P ercent Cropped Area (PCA) adjustment factor of 1.0 i s assumed for surface water

, as

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

in risk concern s, they can be refined.

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

co ndu cted 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. Bo scalid 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 sedi ment (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 bosc alid. Boscalid was detected in 85% of samples, at a maximum

concentration of 36 μ g/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 an d 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 EDWC s for the proposed and relevant previously ev aluated 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 USE S

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

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

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

Fungicide

. BASF Corporation is also seeking registra tion 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. A erial,

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

. The

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

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

previously assessed in drinking water assessments. Th e s e include use in homeowner gardens

### 4 and ornamentals 2 

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

production structures by homeowners 3



### . Turf u ses historically resulted in the highest EDWC s

, 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

unce rtainty 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

- GLG 4 

### , to match use rates on the Pageant la bel (EPA Registration Number) 7969

-

251

. T he 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 greenhous es are assumed to be indoor uses . Uses on lathhouses are

considered to be outdoor use s, 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 structur es 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 a cre 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

(Pag e a nt) 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 p roduction

fields. Homeowne r 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 green houses 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 Co nversion 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 Ex posure Estimated in November 2012 Drinking Water Assessment

Globe Artichoke 0.29

– 0.36

(Pristine) 3 1.1 7

- 14 0 NS None Begin app. a t 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

( exclud ing

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

- 5 b,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) 2 b,h 0.79 7

- 14 14 NS None Prior to disease development

and continue.

On Proposed Label

– Uses ( or Similar Uses ) Assessed Pr ior 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 V egetables c 0.29

(Pristine) 6 b 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

Groups d 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

Group e 0.25

– 0.29

(Pristine) 4 b 1.2 10

- 21 0 NS None Prior to onset of disease and

continue

Fruiting

Vegetables f 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/

Canola i 0.26

(Pristine)

0.22

- 0.26

(Endura) 2 h 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) 2 h 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) 2 h 0.77

(Pristine)

0.53

(Endur a ) 7

- 14 21 NS None Prior to disease development

and continue...if conditions

are conducive for disease

development

Oilseed C rops j 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

Groups k 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) 5 h,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 A pplication rate calculated for P ristine 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 n ot 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 to mato.

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) sequent ial 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, Chines e 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

Pyraclostro bin 12.8 0.0158

WDG=water dispersible granule; SC=suspension concentrate



### 3. ENVIRONMENTAL FATE A ND 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 bosc a lid 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 ana erobic 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 input s, and are not

c onsidered 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

, a s well as for the summed parent plus unextracted

residues

. Half

- lives calculated by summing parent and unextracted residues r anged from 848 to

2553 days in the same five soils

. There w ere on e 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 identifi ed 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.

D issipation 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 detect ed at the deep est depth

sampled (45 cm) at 3 of 14 sites. The t wo 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 diss ipation studies.

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

- carbon

normalized Freundlich distribution coefficients ( K F OC 

### s ) 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 bosca lid 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 AN D INPUT PARAMETERS

Most s urface water EDWC s and some groundwater EDWC s were determined in previous

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

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

discussion of modeling and estimating surface water concentrations. In this assessment

, PRZM

GW (a newly approved model) was used to estimate groundwater EDWC s

, and Tier II modeling

using PRZM and EXAM S 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 comple ted because the cranberry use was expected to be result in

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

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

tomato transpla nts. These uses are assumed to result in exposure s similar to or lower than

previously

- generated EDWC s 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 a l. , 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 through out the soil profile after a pesticide is applied to an agricultural field. PRZM

GW 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 stand ard

scenarios w ere used. PRZM

- GW output s represent pesticide concentrations in a vulnerable

groundwater supply located directly beneath a n agricultural field. Percent Cropped Area

adjustment factors ( PCAs ) are not appli ed to the results of groundwater mo deling , such as

those generated by either the SCI

- GROW or PRZM

- GW model s

.

1.1.a. PRZM/EXAM S (Tier II Surface Water)

Estimated drinking water concentrations (EDWCs) in surface water were gener ated using

EFED’s Tier II aquatic models: PRZM (Pesticide Root Zone Model; vers ion . 3.12 .3, June 2006 )

( Carsel et al. , 1997 ) and EXAMS (EXposure Analysis Modeling System; Vers ion . 2.98.04 .06, April

2005 ) ( Burns, 2000 )

. Calculations were carried out with the linkage program shell

– PE version

5.0 (November 2006)

– which implement s 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 a n adjacent surface water body over a 30

- year period. The combined model s are

expected to provide high

- end estimat es 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 u sing 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 rai nfall data , the receiving water body receives multiple runoff (and possibly spray

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

practices are simulated for 30 year period s ( 1961 t hr o ugh 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 h ectare ( 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 Parameter s

S ummar ies of the model input parameter values used in SCI

- GROW

, PRZM

- GW , and

PRZM/EXAM S 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 ,” Ve rsion 2.1 ( USEPA, 2009 ) and “G uidance for

Selecting Input Parameters for Modeling Pesticide Concentrations in Groundwater Using the

Pesticide Root Zone Model ,” Ve rsion 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, th ese 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 s orption coeffi c ients have been shown to be nonlinear (Freundlich exponents rang ing

from 0.84 to 0.87); however, use of Freundlich coefficients ( i.e

. , K FOC 

### ) in place of linear sorption

coefficients ( i.e

., . K OC 

### ) is expected to have only minor impact on EDWCs. Coefficients of

va riation (CV) were lower for organic carbon normalized solid

- water Freundlich distribution

coefficients (K F OC 

### ; CV= 30 %) as compared to solid

- water Freundlich distribution coefficients (K F 

### ;

CV= 88 %)(MRID 45405216 ). Therefore, the mean K F OC 

### ( 772 ( mg/L)(mg/kg)

- 1/n 

### ) was used to

estimate boscalid concentrations with PRZM

- GW and PRZM/EXAM S

, an d the median K F OC 

### ( 716

(mg/L)(mg/kg)

- 1/n 

### ) was used to estimated groundwater concentration s with SCI

- GROW

.

The aerobic soil metabolism input value used in PRZM

- GW and PRZM/EXAM S was calculated as

the 90 th 

### 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 90 th 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 residu es. Aerobic soil

### 12 median of the same four half

- life value s

. The uses on agricultural crops allow for ground

, aerial

, and airblast applications of a flowable material

. For the agricultural crop uses, EDWC s for

broadcast aerial spray applications were estimated

, as aerial applications result in more spray

drift and therefore higher EDWCs than ground or airblast application s

.

Table 4

. SCI

- GROW (v2.3) Input Parameter Values for Boscalid 1

Parameter Value Source Comments

Application Rate (lbs

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

full explanation. Number of

applications Proposed label

K

oc (mL/g) 716 MRID 45405216 Median of six K FOC 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 25 o C

(days) Parent Only: 578

Parent+Unextracted

Residues: 2454 MRID

45643802 The 90 th percentile upper confidence

bound on the mean of four half

- life

values. Half

- life values adjusted from

27 o C to 25 o C according to input

parameter guidance

.

K

oc (L/kg

- OC) 772 MRID

45405216 Mean of six K FOC values. See text.

metabolism values were measured at 27 o C and were adjusted to 25 o C, 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 re plicate, and was conducted at a higher

- than

- recommended moisture content; therefore,

results from that study (half

- life=108 days) were not includ ed in the develop ment of model input s (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.

EXAM S environment ir 298.exv

-- Index Reservoir

Field Size Index Reservoir

-- --

Runoff Flow Overall

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

-- --

Henry’s Law Constant

(atm

- m 3 /mol) 1×10 - 9

-- Estimated from vapor pressure

at 25 o C and water solubility at

20 o C.

Vapor Pressure (Torr) at

25 o C 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

(K

OC (L/kg

- OC )) 772 MRID 45405216,

45405217 Mean of six K FOC 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 t urf

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 Fol i ar: 3

-- --

Hydrolysis Half

- life @ pH 4,

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

--

Aqueous Photolysis Half

life @ pH 7 (days) Stable (0) MRID 45405206

--

Water Half

- life or Aerobic

Aquatic Metabolism Half

life (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 90 th percentile upper

confidence bound on the mean

of four half

- life values. Half

- life

values were not adjusted for

temperature of 27 o 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 i n Table 7

. Use scenarios evaluated in previous drinking water assessment s

that resulted in the highest EDWC s 10



### , and the proposed uses that were not previously

evaluated were evaluated in this exposure assessment

. PRZM

- GW predicted the highest

EDWC s for the use on turf. For use on turf, t he maximum single

- day concentration of boscalid

(including unextracted residues ) was 7 7 3 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. P ost

breakthrough 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 th at it would take several years for boscalid to reach maximum

concentrations in groundwater.

Simulated u se 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 persisten t. PRZM and EXAM S 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 EDWC s 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 U nextracted 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 . T he scenarios that result ed in the highest EDWC s using half

- lives based on inclusion

of unextracted residues were therefore also modeled using half

- live s 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 un extracted residues are shown

in the T ables 4 and 5

. The inclusion of u nextracted residues in degradation half

- life calculations

did influence EDWC s for groundwater : residues ba sed on boscalid alone were 55

( 423 /7 7 3=0.5 5 ) to 56% ( 389 / 697 =0.56) of those estimated based on boscalid plus unextra c ted

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/A a

(kg

a.i./ha) # of

App Ret.

Int.

days App.

Type 6 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 16467 α

NC 407 370 7292

WI 773

423 * 697

389 * 13295 α

1329 5*

GA 201 187 13529 α

Globe

Artichoke and

Persimmon 0.36

(0.40) 3 7 A 52.39 14.68

0.88 WI 396

216* 357

198 * 13295 α

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* 13295 α

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 13295 α

0.34

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

0.17

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

0.20

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

Tomato 0.37

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

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

### 17 Use Site Single

App. Rate

lbs. ai/A a

(kg

a.i./ha) # of

App Ret.

Int.

days App.

Type 6 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 13295 α

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/EXAM S 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 d ata on bo scalid 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 foun d 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 Unite d 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 f rom 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 ran g ed from 7 to 20

, 589 hectares.

Samples were filtered (0.7 μ m glass fiber filter) prior to extraction 11



### . 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. Bo scalid was first registered in 2003 and samples were

11 Water samples were extracted onto Oasis HLB solid

- phase extraction (SPE) ca rtridges. 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 an d suspended) from

January 2008 through October 2009 from 12 locations with in 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 sampl es 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 Thurw atcher, 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 extraction 12 

### (0.7 μ m glass fiber filter). Boscalid c oncentrations

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 μ g/L. Predicted boscalid surface water EDWC s using EFED modeling ranged from 11 to 426

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

that monitored concentrations are un li kely 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 mon itoring.

Predicted boscalid concentrations in groundwater ranged from 126 to 773 μ g/L , while t he

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

. Groundwater monitoring occurred after just two applications

, whereas the boscalid modeling

results reflect 29

- 100 years of repeated appl ication. PRZM

- GW m odeling 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 m ay occur if boscalid was used for multiple years. While monitored groundwater

concentrations were generally lower than monitored surface water concentrations

, in the study

where in 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 an d 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

- pha se 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

E stuaries 74.5 36000

(wet)

639 (dry) 85% 15 samples

over year 5 2008

-

2009 ( Smalling

and Orlan do,

2011 )

Groundwater

ID, ME, and

WI (potato) 21 2120 a 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 detect e d in 10 of 10 samples at concentrations ranging from 0.35 to 0.81 ng/m 3



### . The

average concentration was 0.53 ng/m 3



### . 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/m 3 ) Maximum

Concentration

(ng/m 3 ) Frequency

of

Detections Limit of

Det.

(pg/m 3 ) Date Source

Strasbourg,

France 0.53 0.81 100 % 27.28 2007 ( Schumer et

al. , 2009 )

Det.=detection or reporting limit



### 8. DRINKING WATER TREAT MENT

There is no information available about the effects of drinking water treatment on bosc a lid

. 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 insta ntaneously mixed throughout

the receiving water body. Fate data show that b oscalid is sta ble to hydrolysis. Therefore,

bosc a lid 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 b oscalid is

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

degradation of bosc a lid would not be expected to occur

. Boscal i d 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 gener ally 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 var ies 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 drink i ng 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 EDWC s for surface water

, inclusion of unextracted residues in half

- life calculations

resulted in EDWC s that are almost identical to those estimated for the parent alone ( i.e

. , within

10 μg/L ), therefore this is sue 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

Aubee, C. 2011.D385653+. Review of Registration Actions for Boscalid: Label Amendment to

Add Greenhouse Use (Pristine) on Tomato and Section 3 New Product Registration

(Pagaent Total Release Fungicide or TC

- 308) for Greenhouse Use as a Fogger on

Ornamentals . D385653+. Environmental Fate and Effects Division. Off ice of Chemical

Safety and Pollution Prevention. United States Environmetnal Protection Agency.

Badriyha, B. N., Ravindran, V., Den, W., & Pirbazari, M. 2003. Bioadsorber efficiency, design,

and performance forecasting for alachlor removal. Water Resear ch, 37

. Baris, R., Barrett, M., Bohaty, R. F. H., Echeverria, M., Villaneuva, P., Wolf, J., et al. 2013.

Guidance for Using PRZM

- GW in Drinking Water Exposure Assessments . December 11,

2012. Environmental Fate and Effects Division. Office of Pesticide Pr ograms. United

States Environmental Protection Agency. Available at

http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_guidance.htm

(Accessed January 22, 20 13).

### 22 Burns, L. A. 2000. Exposure Analysis Modeling System (EXAMS): User Manual and System

Documentation. Revision G . EPA/600/R

- 00/81

- 023. September 2000. Ecosystems

Research Division. National Exposure Research Laboratory. United States

Environmental Protection Agency.

Carsel, R. F., Imhoff, J. C., Hummel, P. R., Cheplick, J. M., & Donigian Jr., J. S. 1997. PRZM

- 3, A

Model for Predicting Pesticide and Nitrogen Fate in Crop Root and Unsaturated Soil

Zones: Users Manual for Release 3.0 . Memorandum From to Environmental Research

Laboratory. Office of Research and Development. United States Environmental

Protection Agency.

Lieu, D. 2010.D380018. Tier I Drinking Water Assessment for Boscalid Used as a Seed

Treatment on Rapeseed (cultivars, varieties, an/or hybrids, including canola and

crambe) . D280018. September 28, 2010. Environmental Fate and Effects Division.

Office of Pesticide Programs. United States Environmental Protection Agency.

Mathur, S. 2002.D285692. Secondary Product Chemistry Revie w of MP . D. B. 3285692. October

31, 2002. Registration Division. Office of Pesticide Programs. United States

Environmental Protection Agency.

Nelson, H., Bietlot, H., & Levy, A. 2003. BAS 510F in/on Various Plant and Animal Commodities.

HED Metabolism Assessment Review Committee (MARC) Memo . D286786. January

9,2003. Health Effects Divison. Office of Pesticide Programs. United States

Environmental Protection Agency.

Reilly, T., Smalling, K., Orlando, J. L., & Kuivila, K. M. 2012. Occurrence of bosc alid and other

selected fungicides in surface water and groundwater in three targeted use areas in the

United States. Chemosphere, 89 , 228

- 234.

Salice, C., & McKinnon, A. A. 2007.D342975+. Ecological Risk Assessment for Proposed Use of

Boscalid on Cotton, Cotton Seed, Fresh Herbs, Tropical Fruits, Ornamentals and Flower

Bulbs . D. D342975, D336599. December 4, 2007. Environmental Fate and Effects

Division. Office of Prevention, Pesticides, and Toxic Substances. United States

Environmental Protection Agen cy.

Schumer, C., Mothiron, E., Appenxzeller, B. M. R., Rizet, A., Wennig, R., & Millet, M. 2009.

Temporal variations of concentrations of currently used pesticides in the atmosphere of

Strasbourg, France. Environmental Pollution, 156 (2), 576

- 584.

Smallin g, K., & Orlando, J. L. 2011. United States Geological Survey. Occurrence of Pesticides in

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

-

09 . Data Series 600. Available at Occurrence of Pesticides in Surface Water and

S ediments 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

Fate and Effects Division. Office of Pesticide Programs. Office of Chemical Safety and

Pollution Prevention. United States Environmental Protection Agency. Available at

### 23 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 . Environment al Fate and Effects Division. Office of

Pesticide Programs. United States Environmental Protection Agency. Available at

http://www.epa.gov/oppefed1/models/water/input_para meter_guidance.htm

(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. Unite d 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 b y 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.ht m (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 Program s. 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

. Mo deling 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 0.588 3 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 0.2 639

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 0.26 97 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

0.032258064516129 47.76 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

0.129032258064516 23.53 15.96 6.507 2.376 1.683 0.5469

0.161290322580645 21.84 15.22 5.305 1.984 1.371 0.393

0.193548387096774 20.45 14.3 4.998 1.812 1.236 0.346

0.22580645161 2903 14.57 10.03 3.945 1.786 1.207 0.3344

0.258064516129032 8.31 5.797 2.28 1.385 0.9477 0.3144

0.290322580645161 7.911 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 0.354838709677419 5.903 4.225 1.906 1.102 0.7632 0 .249

0.387096774193548 5.743 4.155 1.847 1.072 0.7499 0.2475

0.419354838709677 5.494 4.085 1.792 1.057 0.7276 0.2459

0.451612903225806 5.281 3.73 1.615 0.9426 0.6782 0.2406

0.483870967741936 4.636 3.372 1.597 0.8759 0.6663 0.2358

0.516129032258065 4.616 3. 239 1.562 0.8541 0.5883 0.2181

0.548387096774194 4.239 3.001 1.553 0.812 0.5869 0.2175

0.580645161290323 4.035 2.952 1.463 0.8075 0.5823 0.2163

0.612903225806452 3.819 2.655 1.412 0.7859 0.5818 0.2134

0.645161290322581 2.777 2.122 1.392 0.7714 0.5798 0.206 3

0.67741935483871 2.68 1.904 1.39 0.7458 0.5571 0.2058

0.709677419354839 2.373 1.899 1.232 0.7225 0.5227 0.1949

0.741935483870968 2.278 1.874 1.057 0.6723 0.5129 0.1878

0.774193548387097 2.16 1.69 0.985 0.6267 0.4905 0.176

0.806451612903226 1.928 1.672 0. 959 0.5863 0.4316 0.1497

0.838709677419355 1.701 1.621 0.9122 0.4522 0.3985 0.1437

0.870967741935484 1.561 1.266 0.9052 0.4223 0.3119 0.137

0.903225806451613 1.351 1.097 0.8438 0.4185 0.3006 0.1302

0.935483870967742 1.184 0.8555 0.6659 0.2697 0.1972

0.1108

0.967741935483871 0.5701 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 s ol 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 da ys 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 app rate 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 2 0.8 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 1.1 86

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

0.032258064516129 145 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

0.129032258064516 54.95 36.58 14.58 7.133 5.406 1.569

0.1 61290322580645 47.42 35.43 12.6 6.112 4.387 1.475

0.193548387096774 46.02 31.85 11.51 5.768 4.337 1.459

0.225806451612903 41.61 29.01 11.12 5.622 3.89 1.345

0.258064516129032 38.6 26.99 11.05 5.251 3.888 1.321

0.290322580645161 35.58 24.35 10.64 5.222 3.88 1.295

0.32258064516129 35.46 23.91 10.48 5.195 3.776 1.245

0.354838709677419 35.16 23.02 9.507 4.926 3.769 1.224

0.387096774193548 30.2 21.82 9.485 4.899 3.6 1.186

0.419354838709677 29.82 20.8 9.279 4.89 3.374 1.169

0.451612903225806 29.19 20.69 8.814 4.5 25 3.112 1.151

0.483870967741936 26.34 18.33 8.702 4.291 3.044 1.06

0.516129032258065 25.67 17.97 8.148 4.273 2.974 1.058

0.548387096774194 24.37 15.92 8.054 4.037 2.935 1.037

0.580645161290323 23.1 15.75 7.586 3.615 2.9 1.011

0.612903225806452 23.05 15.75 7.233 3.475 2.568 0.9913

0.645161290322581 20.97 14.57 6.742 3.447 2.552 0.9494

0.67741935483871 19.9 14.14 6.215 3.388 2.371 0.9478

0.709677419354839 19.4 12.58 5.717 3.239 2.327 0.9262

0.741935483870968 17.88 11.97 5.489 3.196 2.316 0.917

0.774193548387097 17.65 11.82 5.45 2.942 2.214 0.9005

0.806451612903226 17.64 11.74 5.264 2.66 2.064 0.8759

0.838709677419355 17.33 11.49 5.041 2.594 1.996 0.7465

0.870967741935484 16.89 11.3 4.802 2.556 1.815 0.738

0.903225806451613 16.53 10.67 4.249 2.53 7 1.803 0.6772

0.935483870967742 12.33 8.759 3.696 2.483 1.781 0.6327

0.967741935483871 7.522 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

- Novem eber 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

H enry'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 l ine 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 0.835 3 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 0.1 651 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

0.032258064516129 11.9 8.952 4.313 2.196 1.494 0.3761

0.0645161290322581 8.975 7.441 3.198 1.408 0.9534 0.23 99

0.0967741935483871 7.305 5.453 3.14 1.387 0.9368 0.236

0.129032258064516 7.119 5.21 2.665 1.208 0.8255 0.2075

0.161290322580645 6.329 4.951 2.495 1.199 0.8083 0.2031

0.193548387096774 6.028 4.935 2.198 1.155 0.7859 0.1982

0.225806451612903 5.756 4.294 2 .072 1.086 0.7531 0.1902

0.258064516129032 5.464 3.968 1.979 0.9792 0.6724 0.1693

0.290322580645161 4.534 3.33 1.41 0.8145 0.5611 0.1419

0.32258064516129 4.501 3.304 1.304 0.6981 0.4749 0.1196

0.354838709677419 3.593 2.68 1.251 0.5788 0.4631 0.1175

0.38709 6774193548 3.097 2.505 1.178 0.5059 0.3461 0.08725

0.419354838709677 2.383 1.832 1.059 0.4521 0.309 0.08109

0.451612903225806 1.699 1.286 0.8649 0.4045 0.304 0.07818

0.483870967741936 1.281 0.9226 0.6101 0.3731 0.3024

0.07671

0.516129032258065 1.118 0.8865 0.6061 0.3285 0.2847

0.07249

0.548387096774194 1.103 0.8586 0.602 0.301 0.2301 0.05804

0.580645161290323 1.099 0.8385 0.6011 0.2909 0.1962

0.04946

0.612903225806452 1.098 0.8353 0.5944 0.2823 0.1899

0.04831

0.645161290322581 1.097 0.8325 0.5918 0.2819 0.1897

0.04829

0.67741935483871 1.091 0.8263 0.5889 0.268 0.1825 0.04793

0.709677419354839 1.09 0.8261 0.588 0.2668 0.1795 0.04783

0.741935483870968 1.09 0.8253 0.5876 0.2653 0.1783

0.04711

0.774193548387097 1.088 0.8241 0.5859 0.2593 0.1773

0.04652

0.8064 51612903226 1.088 0.8215 0.5843 0.2536 0.1706

0.04592

0.838709677419355 1.077 0.8112 0.5775 0.2515 0.1693

0.0447

0.870967741935484 1.077 0.809 0.5771 0.2499 0.1683 0.04324

### 30 0.903225806451613 1.074 0.8083 0.5756 0.2468 0.1672

0.04234

0.935483870967742 1.068 0.8008 0.5703 0.245 0.1651 0.0423

0.967741935483871 1.065 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 th is 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 a pplied 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 a pprate 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)