### 1

**MEMORANDUM DATE:**  April 0 4 , 2013 **SUBJECT:** Addendum of Drinking Water Exposure Assessment for the Section 3 New Use of

Py raclostrobin on Various Agricultural Crops and Residential Ornamentals **TO** : Andrew Ertman , Risk Manager Reviewer

Barbara Madden , Product Manager Registration Division (7505P) **FROM:** Faruque Khan , Ph.D. Senior Fate Scientist

Environmental Risk Branch I Environmental Fate and Effects Division (7507P **) APPROVED**  **BY:** Edward Odenkirchen, Ph.D , Acting Branch Chief

Sujatha Sankula, Ph.D. Lead Biologist Environmental Risk Branch I Environmental Fate and Effects Division (7507P) **Executive Summary** This is an addendum to the earlier memorandum related to drinking water exposure assessment issued on February

13, 2013. This revised memorandum reflects recently withdrawn cranberry use b y the registrant. In addition, exposure of py raclostrobin in ground water was evaluated with the PRZM
- GW model as well as recent published py raclostrobin monitoring data were summarized in this memorandum. The estimated drinking water concentrations (EDWCs ) of py raclostrobin ( carbamic acid, [2
-[[[1
- (4
- chlorophenyl)
- 1H
- pyrazol
- 3
-

yl[oxy ]m ethyl ]phenyl methoxy
-,methyl ester] ) in surface water and ground water in support of the proposed Section 3 new use of p yraclostrobin for control of a variety of fungi on several use sites were summarized below. The Interregional Research Project Number 4 is seeking registration of several new uses (described in **Table 1** ) of py raclostrobin on one supplemental label for Cabrio ® 

### Fungicide and one supplemental label Headline ® 

### Fungicide as well as four supplemental labels for Pristine ® OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

### UNITED STA**TES ENVIRONMENTA L PROTECTION A** **GENCY** WASHINGTON, D.C. 20460



### PC Code : 099100

**DP Barcode s**  **:** D403871, D405066

### 2

Fungicide. Summary

of directions for the proposed uses of py raclostrobin were provided in **Table 1**
. Some of the proposed end use products contain two active ingredients p yraclostrobin and bosc alid. However, this assessment focuses onl y on the active ingredient pyraclostrobin. No degradates of p yraclostrobin were included in the drinking water assessment based on the recommendation from the Metabolism Assessment Review Committee (MARC) of Health Effects Division (USEPA 2001, D278044). The EDWCs for both surface and ground water recommended for use in HED’s human health dietary risk assessment are summarized in **Table 2** 
. Estimated py

raclo s trobin concentrations in surface water and ground water used for drinking water are summarized in **Table 6**
. F or the proposed use of py raclostrobin in fruiting vegetable s resulted in the highest surface water concentration s of at 16.6 μg/L for 1
- 10 year peak value from ground application and 1
- 10 annual ye ar average of 1.1 μg/L from aerial application. The acute and chronic EDWCs resulting from the proposed application uses are lower than the EDWCs for surface water in the previously recommended drinking water assessments for p yraclostrobin for turf uses (USEPA 2007 D389729+)
. Since the EDWCs for surface water for proposed uses are lower than the previously recommended EDWCs for this chemical, the EDWCs for surface water will not supersede the EDWCs previously

recommended for turf use. The Percent Cropped Area of 1.0 was assumed as p yraclostrobin has uses on ornamentals, turf, and a variety of agricultural crops. Revised EDWCs in groundwater supersede d the EDWCs previously recommended for turf use
. Recent monitoring data show p yraclostrobin detection of a maximum of 23.9 ng/L in surface water and a maximum of 4.8ng/L groundwater samples (Reilly et al. , 2012).
**Table 1**  **. Proposed**  **New Uses**  **and Conversion of**  **Old Crop Groups to New Crop Groups for Pyraclo**  **s trobin**  Use Site Single App.

Rate (lbs. ai/A) a # of

App Seasonal App. Rate (lbs. ai/A) Retreat

ment Interval (days) PHI App.

Type b Geographic Restrictions EPA Reg # Comments Proposed New Uses

– Artichoke (Globe) 0. 15

– 0. 18 3 0.55 7 - 14 0 A, G,S None 7969
- 199 Begin app. At the initiation of the protection phase when approximately 25% of the plants have bolted.
Belgium Endive 0.8 to 1.6 oz. per 1000 lbs roots c 7969
- 199 Application made to roots when brought into cold storage and at the beginning of forcing. Persimmon 0. 15

– 0. 18 3 0.55 7 - 14 0 A, G,S None Prior to onset of disease development
Sugarcane 0.15
- 0.2 4 0.78 14
- 28 14 A, G,S None 7969
- 289

### 3

**Table 1**  **. Proposed**  **New Uses**  **and Conversion of**  **Old Crop Groups to New Crop Groups for Pyraclo**  **s trobin**  Use Site Single App.

Rate (lbs. ai/A) a # of

App Seasonal App. Rate (lbs. ai/A) Retreat

ment Interval (days) PHI App.

Type b Geographic Restrictions EPA Reg # Comments
Residential Ornamentals 0.156 6 0.93 14 0 NS d None 7969
- GLG Conversion of old crop group to new crop group Bulb vegetables (Group 3
- 07) 0.1
- 0.15 6 0.9 14 7 A, G,S None 7969
- 199 Prior to onset of disease and continue Bushberry and Caneberry subgroup (13
- 07B) 0. 15

– 0. 18 4 0.73 7 - 14 0 A, G,S Not for use in CA 7969
- 199

Prior to onset of disease and continue
Citrus Fruit Group (10
- 10) 0. 15

– 0. 24 4 0.88 10
- 21 0 A, G,S None 7969
- 289 Prior to onset of disease and continue Fruiting Vegetables Group (8
- 10) 0.1 0
- 0.20 6 1.2 5 - 14 0 A, G,S Not for use in CA 7969
- 187

Prior to onset of disease and continue Low growing berry subgroup (includes cranberry) (13
- 07G) 0. 15

– 0. 18 5 0. 92 7 - 14 0 A, G,S None 7969
- 187 No later than 10% bloom or prior to disease development and continue Oilseed crops Group 20 0.10
- 0.20 2 0.39 7 - 14 21 A, G,S None 7969
- 289 Prior to disease development and continue...if conditions are conducive for disease development Pome Fruit Groups (11
- 10) 0. 11

– 0. 15 4 0.6 7 - 14 0 A, G,S None 7969
- 187 Begin applications prior to disease development and continue. Root vegetables, 1B (except sugar beets) 0.06
- 0.17 6 0.52 7 - 14 0 AGS None 7969
- 199 Begin applications prior to disease development and continue. Small fruit, vine climbing subgroup 13
- 07F (except fuzzy kiwifruit) 0.1 0

– 0. 15 6 0.9 10
- 21 14 A, G,S None 7969
- 187 Prior to onset of disease when conditions favor disease during early bloom, bunch pre
- closure and veraison. To mato transplants for homeonwers market4 0. 1

– 0. 2 2 1.1 5 - 14 0 A, G,S None Prior to disease development and continue

### 4

**Table 1**  **. Proposed**  **New Uses**  **and Conversion of**  **Old Crop Groups to New Crop Groups for Pyraclo**  **s trobin**  Use Site Single App.

Rate (lbs. ai/A) a # of

App Seasonal App. Rate (lbs. ai/A) Retreat

ment Interval (days) PHI App.

Type b Geographic Restrictions EPA Reg # Comments Turnip greens 0.15

– 0.20 2 0.4 7 - 14 14 A, G,S None Prior to disease development and continue.

a Adopted from “Summary of Directions for the P roposed Uses of Pyraclostrobin “ provide by Registration Division (Appendix X) b Application methods : Aerial (A) , Ground (G) and S p rinkler (S) c Indoor use , exposure to surface water and groundwater would be low . No exposure assessment was performed d Not Specified, assumed hand spray 4 Since tomato is in the fruiting vegetable cropgroup, no separate exposure assessment was performed for drinking water. 

### Table 2. **Recommended EDWCs for Drinking Water risk assessment for pyraclostrobin**  **Use Source of Drinking**  **Water Pyraclostrobin**  **concentration in drinking water (** μg/L) **Acute 1**  

### Non **- Cancer** 

**Chronic 1**  

### Cancer Chronic **1** Surface Water 35.6 2.3 1.5 Groundwater2 0. 0 6 0.02 0.02 1 These are the highest EDWCs for previously evaluated use scenarios and the estimated acute and annual average surface water concentrations were 35.6 and 2.3 μg/L respectively. Previously estimated groundwater concentrations for acute was 0.02 μg/L 2007, D389729+
. 2 EDWCs based on PRZM
- GW model 

### Proposed Use **s** The Interregional Research Project Number 4 is seeking registration of several new uses (described in **Table 1** ) of py raclostrobin on one supplemental lab el for Cabrio ® 

### Fungicide and one supplemental lab el Headline ® 

### Fungicide a s well as four supplemental labels for Pristine ® 

### Fungicide. This assessment examines potential exposure to pyraclostrobin only
. A erial, chemigation, and ground applications are proposed for the agricultural crops
. F ive of the proposed uses were considered as not being previously asses sed in drinking water assessments. These include use on globe artichoke, persimmon, low growing berries, sugarcane , and ornamentals (homeowner)
. Since aerial application provides higher exposure, major crops scenarios were simulated with aerial application . A ground application scenario was used to compare with the highest exposure scenario of aerial application (PA tomato STD). Resulted EDWCs for both aerial and ground are very comparable. Sprinkler irrigation assumed to be similar to ground application. An additional new use for B elgium endive was not considered in this assessment due to indoor use of py raclostrobin.

### 5

**Residues of Concern** The Metabolism Assessment Review Committee (MARC) reported that the residue of concern for py raclostrobin in drinking water is the parent only (USEPA 2001, D278044). **Modeling Approach and Input Parameters**  **Models Surface Water**  The EDWCs were generated using EFED’s standard suite of models. Pesticide Root Zone Model (PRZM v3.12 .2, May

12, 2005 ) and Exposure Analysis Modeling S ys tem (EXAMS v2.98.04 .06, Apr. 25, 2005 ) are simulation models coupled with the input shell PRZM/EXAMS (PE v5.0, Nov. 15, 2006 ) to generate EDWCs of py raclostrobin residues that may occur in surface water for drinking water. The PRZM model simulates pesticide movement and transformation from crop application through soil residue processes. The EXAMS model simulates pesticide loading via runoff, erosion, and spray drift assuming a standard watershed of 172.8 ha that drains into an adjacent standard drinking water index reservoir of 5.26 ha, an average depth of 2.74 m. A more detailed description of the index reservoir watershed can be found in Jones et al. , 1998. Standard percent cropped areas (PCA) were use d for proposed uses as estimates of the extent of watershed on which crops are grown. The default PCA of 1.0 was used for the proposed uses because py raclostrobin can be used in both agricultural and non
- agricultural settings (USEPA 2012). **Ground Water** Screening Concentration in Ground Water (SCI
- GROW v2.3, Jul. 29, 2003) is a regression model used as a screening tool to estimate pesticide concentrations found in ground water used as drinking water. The SCI
- GROW model and user’s manual may also be downloaded from the EPA Water Models web
- page (http://www.epa.gov/oppefed1/models/water/#scigrow). PCAs are not used with the SCI
- GROW model. In addition, Tier 1 groundwater EDWCs for p yraclostrobin, resulting from its use on various crops were also derived using the PRZM
- GW model (Pesticide Root Zone Model for Groundwater, version 1.0, August 31, 2012), with the GW
- GUI (Graphical User Interface , version 1.0, August 31, 2012). PRZM
- GW is a one
- dimensional, finite
- difference model that estimates the concentrations of pesticides in groundwater. It accounts for pesticide fate in the crop root zone b y simulating pesticide transport and degradation through the soil profile after a pesticide is applied to an agricultural field. PRZM
- GW permits the assessment of multiple years of pesticide application (up to 100 years) on a single site. Six standard scenarios, each representing a different region known to be vulnerable to groundwater contaminations, are available for use with PRZM
- GW for risk assessment purposes. In PRZM
- GW simulations, each of these standard scenarios was used. PRZM
- GW output values represent pesticide concentrations in a vulnerable groundwater suppl y that is located directl y beneath a rural agricultural field following many ye ars of pesticide application.

### 6

**Input Parameters** A summary

of the model input parameter values used in PRZM/EXAMS , SCI
- GROW, and the PRZM_GW Model s are in **Table 3, Table 4, and Table 5** presented in respectivel y . 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 )
. S ample model output files are located in **Appendix B. Table 3**  **. PRZM/EXAMS Input Parameters for Pyraclostrobin Proposed Uses Parameter**  **Input Value Source**  **Comment**

**Use Site** Scenario and Application Date **Artichoke (Globe)** CA Row Crop RLF Multiple application date s 1 Label directions

See Section titled “Proposed Use” for full explanation A combination of label directions and information related to crop profile in current scenarios for PRZM/EXAMS **Bulb vegetable Group (3 -**  **07)** CA Onion STD Multiple application date s Label directions **Bushberry and caneberry subgroup (13**  **- 07 A)**  OR Berries STD Multiple application date s Label directions **Low growingberry (13 -**  **07G)** CA Strawberry STD FL Strawberry STD Multiple application date s Label directions **Citrus Fruit Group (10 -**  **10)** CA Citrus STD FL Citrus STD Multiple application date s Label directions **Fruiting Vegetable Group (8**  **- 10)**  FL Tomato STD PA Tomato STD FL Pepper STD Multiple application date s Label directions Not for use in CA **Oilseed Group (20)** MS Cotton STD NC Cotton STD ND Canola STD Label directions **Pom e Fruit Group (11**  **- 10)**  NC Apple STD OR Apple STD PA Apple STD Multiple application date s Label directions **Root vegetables 1B** FL Carrot ID Potato ME Potato Multiple application date s Label directions (Except sugarbeet)

### 7

**Table 3 . PRZM/EXAMS Input Parameters for Pyraclostrobin Proposed Uses**  **Parameter Input Value**  **Source Comment**  **Sm all Fruit, vine climbing**  **subgroup** CA Grape STD NY Grape STD Multiple application date s Label directions ( Except fuzzy kiwifruit) **Sugercane** FL Sugarcane STD LA Sugercane Multiple application date s Label directions

**Turnip Greens** Label directions Since the scenarios for turnip same as root vegetables and application rate for turnip is lower than the root vegetables group, no PRZM/EXAMS mo deling was performed. Assumed EDWCs for turnip would be lower than the EDWCs for root vegetable s

**Ornam entals (Residential)**  CA Residiential RLF CA Impervious RLF March 1 Label provides partial information related to application. Registration Division (personal communication) provided application rate and frequency of application. Used similar approach described for Endengered Species Assessment Residential scenario with 100% application rate Im pervious scenario with 1.68% of application rate Post process for exposure 2 Applications per year See Table 2 Label directions See Section titled “Proposed Use” for full explanation Application method Foliar
- Aerial, ground and sprinkler irrigation Label directions Apply to all proposed uses CAM 2 Default for foliar application Hydrolysis (t 1/2 ) 0 MRID 46902201 Stable

### 8

**Table 3 . PRZM/EXAMS Input Parameters for Pyraclostrobin Proposed Uses**  **Parameter Input Value**  **Source Comment**  Spray drift fraction Aerial: 0.16 Ground: 0.64 Sprinkler Irrigation: PRZM/EXAMS input guidance document Default for foliar application for drinking water assessment Aerobic soil metabolism (t 1/2 ) 24 7 . 2 days 45118631 MRID 45118632 MRID 45367504 Upper 90 th %
- ile confidence bound on the mean of six half
- lives 3 Aerobic aquatic metabolism (t 1/2 ) 45.1 days MRID 45118637 90 th%ile reported half
- lives for 14 C labeled chlorophenyl (8.4 days) and tolyl ( 26.4 days) rings. Anaerobic aquatic metabolism (t 1/2 ) 12.1 days MRID 45118634 90 th%ile reported half
- lives for 14C labeled chlorophenyl (191 days) and tolyl ( 6.91 days)rings. Aquatic photolysis (t 1/2 ) 0. 11 days MRID 45118629 90 th%ile reported half
- lives for 14C labeled chlorophenyl (0.05 days) and tolyl ( 0.08) days)rings. Vapor pressure 6.88×10 -- 7 (mmHg) -- MRID 470780
- 01to 470780
- 08 Solubility in water (pH 7, 20 °C) 2.7mg/L
-- Molecular weight 388 g/mole
-- Henry’s Law constant (20 °C) 1.3×10 - 7 atm.m3 /mol -- Estimated 1 Partition coefficient Koc 9304 mL/g MRID 46808411 Average Koc (7889, 16000, 7889, 6000, 9000, 9436, and 9304 ) 1 = Since pyraclostrobin can be applied based on pest pressure, multiple application dates were used to simulates pyraclostrobin exposure in drinking water. Application dates and exposure were provided in appendix X 2 [(Residential EEC) x (0.5 amount pervious surface) x (% treated, 0.15 for woody ornamental)] + [Impervious Surface EEC x 0.5 amount impervious surface] 3 = http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

### 9

**Table 4. SCI -**  **GROW (v2.3) Input Parameter Values for Pyraclostrobin Param** **eter Value**  **Source Comments**  Application Rate (lb s a.i./acre ) 0.184 EPA Reg # 7969
- 199 Proposed label Number of applications 5 EPA Reg # 7969
- 199 Koc (mL/g) 9000 MRID 46808411 Median of seven KOC values. There is not a three fold difference in observed

values. Aerobic soil metabolism t 1⁄2 (days) 161 MRID 45118631 MRID 45118632 MRID 45367504 Median of four values. There was not a five
- fold difference in values.
**Table 1**  **. Input values for the PRZM** **- GW**  **model for ptraclostrobin**  **. Variable Nam** **e Data Value**  **Data Source MRID(s)**  **Comment** Application Method Aerial (fruiting vegetable), Proposed labels EPA Reg# 7969
- 187 Application Rate (lbs. a.i./acre) [kg/ha] 0.20 [0.22] (fruiting vegetable), Proposed labels EPA Reg# 7969
- 187 Application Frequency 6 times per year Proposed labels EPA Reg# 7969
- 187 Application Interval (days) 5 days Proposed labels EPA Reg# 7969
- 187 Hydrolysis t 1/2 = stable 48409101 EPA Reg# 7969
- 187 Aerobic Soil Metabolism t 1/2 = 247.2days 45118631 MRID 45118632 MRID 45367504 Upper 90 th %
- ile

confidence bound on the mean of six half

lives 1
Koc 93 04 mL/g oc MRID 46808411 Average Koc (7889, 16000, 7889, 6000, 9000, 9436, and 9304 ) 1 **1** EFED input parameter guidance: http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_input_guidance.htm 

### Table 5. Modified Tier I Rice Model (for Estimating Exposure from Use on Cranberries) **Input Parameters for Pyraclostrobin**  **Input Parameter Value**  **Comments Source**  Application rate (lbs a.i./A) 0.88 Maximum proposed annual application rate Proposed label Organic carbon partition coefficient (Koc ) (L/kg OC ) 9304 Represents the mean Koc value for parent (n= 7 ) MRID 46808411

### 10

**Modeling Results** Estimated py

raclotrobin concentrations in surface water and ground water used for drinking water are summarized in **Table 6**
. Estimated concentrations in surface water for use on fruiting vegetable resulted in the highest EDWC at 16.6 μg/Lfor acute from ground application and annual average of EDWC s from aerial application
. Acute estimated py raclotrobin concentrations in surface water used for drinking water for other uses ranged from 1.4 to 16.6 μg/L. Estimated annual average concentrations ranged from 0.1 to 0.9 μg/L. S CIGROW model s imulated concentrations in ground water was 6.2 E - 03 μg/L for the highest application rate . The SCIGROW and PRZM
- GW concentration s represent groundwater concentration that might be expected in shallow unconfined aquifers under sandy soils. All PRZM
- GW scenarios , 3 required the use of an extended weather file, which allows the user to run the simulation for up to 100 years in order to observe breakthrough. PRZM_GW simulated groundwater concentrations are lower than SCIGROW model and listed in Table 7 for six vulnerable sites
. 

### Table **6 . EDWCs for**  **Pyraclostrobin A pplications to**  **Various Crop s and Home Owner**  **Garden Drinking**  **Water Source Crop** 

Crop Scenario **1 -** **in -**  **10 -** **year**

**Peak Exposure 1**  **- in**  **- 10**  **- year** 

**Annual Mean Exposure**  **30 -** **year Mean**

**Exposure Concentration (μg/L)** 

Surface water 1 **Artichoke**

CA Rowcrop_RLF 2.2
- 3.1 0.2 0.1 **Berry -**  **bush/cane** OR Berry STD 2.5
- 4.1 0.3
- 0.4 0.3 **Berry -**  **low growing** FL Straw berry STD 4.8
- 5.1 0.4
- 0.5 0.3
- 0.4 **Bulb vegetable** CA Onion STD 1.6 0.1 0.1 **Citrus** CA Citrus STD FL Citrus STD 1.9
- 2.0 4.7
- 8.6 0.1
- 0.2 0.5 0.1

0.3
- 0.4 **Fruiting vegetable** CA Tomato STD FL Pepper STD FL Tomato STD PA Tomato STD PA Tomato STD (G) 2 2.0
- 2.7 8.7
- 9.1 8.8
- 10.9 11.3
- 16.2 11.2
- 16.6 0. 3
- 0.4 0.8 0.8
- 0.9 0.8
- 1.1 0.8
- 1.0 0.2
- 0.3 0.6 0.7
- 0.6 0. 7 - 0.9 0.6
- 0.8 **Oilseed** MS Cotton STD NC Cotton STD ND Canola STD 5.8
- 7.6 .8
- 7.5 1.9
- 2.8 0.4
- 05

0.3
- 04 0.1 0.3

0.3 0.1 **Pom e Fruits**  NC Apple STD OR Apple STD PA Apple STD 4.6
- 8.6 3.9
- 6.1 0. 4
- 0. 5

0. 2
- 0. 3 0. 3
- 0. 4 0.3 0.2 0.2 **Persimmon** NC Apple STD 9.1
- 5.3 0.4 0.3 **Root Vegetable** FL Carrot STD ID Potato STD 3.9
- 6.0 1.7
- 1.8 0.4 0.1 0.3

0.1

### 11

**Table 6**  **. EDWCs for Pyraclostrobin A** **pplications to Various Crop**  **s and Home Owner Garden**  **Drinking Water Source**  **Crop**

Crop Scenario **1 -** **in -**  **10 -** **year**

**Peak Exposure 1**  **- in**  **- 10**  **- year** 

**Annual Mean Exposure**  **30 -** **year Mean**

**Exposure Concentration (μg/L)**  ME Potato ST D 4.4
- 5.8 0. 4
- 0. 5 0. 3 0. 4 **Sm all Fruit (Vine)**  CA Grape STD NY Grape STD 1. 4
- 1. 7 10. 7 - 13.9 0.2 1.2
- 1.3 0.2 0.9 **Sugarcane** FL Sugarcane STD LA Sugarcane STD 6. 7 - 9.9 9. 6
- 13.8 0. 8
- 0. 7 - 08

0. 9
- 1.0 0. 05
- 0. 08 0. 7 Home Owner Garden
Woody Ornamental CA Residential STD 3.6 0.2
- 

### Groundwater Generic Scenario 6.08 E - 03 6.08 E - 03 6.08 E - 03 1 = Surface water EDWCs are estimated for aerial application 3 = The reported EDWCs are based on ground application to compare with the highest EDWCs for the PA Tomato scenario for aerial application.

**Table 7**  **. PRZM -**  **GW results based on pyraclotrobin**  **use. Crop**  **Scenario Highest**  **Daily Value (**  **μ g/L)**  **Post**

**Breakthrough A** **verage ( μ** **g/L) Average**  **S im** **ulation**

**Breakthrough Time (days)**  Tomato ( 0.2 0 lbs a.i./A x 6 applications ) FL citrus 6.15E
- 02 1.59E
- 02 Incomplete FL potato 7.45E
- 11 1.68E
- 11 Incomplete GA peanut 1.59E10 9.94E
- 12 Incomplete NC cotton 4.88E
- 04 1.24E
- 04 Incomplete DELMARVA sweet corn 5.54E
- 05 7.04E
- 06 Incomplete WI corn 3.5E
- 09 2.23E
- 10 Incomplete 

### Monitoring Data Data on py

raclostrobin were available in the United States Geological Survey (USGS ) National Water- Quality Assessment (NAWQA) P rogram Data Warehouse (http://infotrek.er.usgs.gov/nawqa_queries/jsp/swmaster.jsp ) searched on February 11 , 2013
. Py raclostrobin was not detected in the surface water sample s collected in Georgia (limit of quantitation (LOQ) = 2.8 ng/L)
. Ten bottom material samples were also collected in Georgia and py raclostrobin was not detected (L OQ = 1. 6 μg/kg
- sediment) in all ten samples. However, recentl y Reill y et al. (2012) reported p yraclostrobin residue s in surface water and groundwater samples. For surface water, a total of 60 water samples were analyz ed for p yraclostrobin. Py raclostrobin was detected in 42% of surface water samples. The maximum concentration of py raclostrobin in surface water was 23.9 ng/L. For groundwater, a total of 12 water samples

### 12

were anal yz ed for p yraclostrobin. Py raclostrobin was detected in 40 % of ground water samples. The maximum concentrations of py raclostrobin ranged from non
- detect to 4.8 ng/L. **Drinking Water Treatment**  There is no available information on the effects of drinking water treatment on py raclo s trobin
. 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 surface water via spray

drift or surface runoff and it is instantaneously mixed and concentrations are observed in the water body
. Py raclostrobin is sta

ble to hydrol ys is. Therefore, py raclo s trobin will not degrade b y hydrolysis during the time that elapses from drinking water intake through distribution to the first tap. Py raclo s trobin is also stable to aqueous photolysis. Therefore, if ultraviolet light were used as a means of disinfection, degradation of py raclostrobin would not be expected to be significant
. Py raclostrobin has long degradation rate in aerobic aquatic metabolism and aerobic metabolism is therefore, not expected to be a significant loss mechanism in water treatment . The most successful drinking water treatment process for removal of pesticides from drinking water is thought to be treatment with granular activated carbon (GAC) which is only

used in larger drinking water treatment facilities. The ability of GAC to remove pesticides will vary

with the properties of the chemical, the viability of the biofilm on the GAC, and whether the sorption site s on GAC have reached capacity ( Badri yha et al. , 2003 ; Zhao et al. , 1999 ) . Data on the sorption of py raclostrobin to GAC are not available ; however, high Koc ( 9304 mL/g) value of p yraclostrobin suggests that there is a potential for removal of py raclostrobin through GAC treatment due to its high adsorption coefficient
. **Uncertainties** The highest estimated concentrations provided in this assessment were generated from Tier 1 models and are conservative estimates of py raclostrobin concentrations in untreated drinking water. There were a number of uncertainties associated with this drinking water exposure assessment. The major uncertainty is from the use of the Tier I Rice Model with a modified depth for cranberries. This model only estimates a peak concentration inside the bog. Therefore, it likely overestimates chronic concentrations and is expected to be conservative for acute/peak EDWC as water will have a residence time between leaving a cranberry bog and reaching a drinking water intake. Additionally, the model was originall y developed for rice and management of cranberries is different than rice and the model was not validated using monitoring data for cranberries. Therefore, there is some uncertainty in using the model for cranberries. Additionally, the Tier I Rice Model does not account for degradation and the annual average EDWC is likely

overestimated; however, due to py raclostrobin’s stability

in water, the overestimation may

not be that high. An additional element of uncertainty derives from the conceptual model used in this assessment, whereb y applications of pesticide are made to a single bog. In reality, the water used to flood a cranberry bog may be “recycled” and used to flood multiple bogs, and/or stored and used to re
flood the same bog later during the ye ar. Thus, the same volume of water may receive greater pesticide loadings than label restrictions would seem to imply
. Additionally, applications may be made to dry

cranberry bogs that are subsequently flooded.

### 13

**Literature Cited** Jones, R. D., S. Abel, W. R. Effland, R. Matzner, R. Parker. 1998. An Index Reservoir for Use in Assessing Drinking Water Exposure. Proposed Methods for Basin
- scale Estimation of Pesticide Concentrations in Flowing Water and Reservoirs for Tolerance Re assessment. Presentation to FIFRA Science Advisory Panel, June 29
- 30, 1998. Online at: http://www.epa.gov/scipoly /sap/1998/index.htm Reilly, T.J., Smalling, K.L., Orlando, J.L . and K.M. Kuivila. 2012. Occurrence of boscalid and other selected fungicides in surface water and groundwater in three targeted use areas in the United States. Chemosphere 89:228
- 234. USEPA, 2007. Py

raclostrob in. Outcome the the HED Metabolism Assessment Review Committee (MARC) Meeting Held on September 20, 2001. Health Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency (D 278044). USEPA, 2007. Drinking water assessment for turf and golf courses. Environmental Fate and Effects Division. Office of Pesticide Programs. United States Environmental Protection Agency (D D389729+
. 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 http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm (Accessed February 10 , 2013 ). USEPA. 2010. Guidance on Development and Use of Percent Cropped Area Adjustment Factors in Drinking W

ater Exposure Assessments . Environmental Fate and Effects Division, Office of Pesticide Programs, United States Environmental Protection Agency . Available at http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.pdf (Accessed November 29, 2010). 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 R esearch, 33 (13).

### 14 **Appendix A : Model Outputs**  **Model: PRZM/EXAMS** stored as PATomG_DW_15
- 07.out Chemical: Pyraclostrobin PRZM environment: PAtomatoSTD.txt , m odified Tueday, 29 May 2007 at 14:01:58 EXAMS environment: ir298.exv, m odified Tueday, 26 August 2008 at 06:14:08 Metfile: w14751.dvf, modified Tueday, 26 August 2008 at 06:15:00

**Water segment concentrations (ppb)** Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 5.9 5.1 2.7 1.5 1.1 0.4 1962 6.5 5.3 2.7 1.9 1.7 0.8 1963 6.7 5.5 2.9 2.3 1.7 0.7 1964 3.3 2.8 1.9 1.4 1.2 0.7 1965 3.6 3.1 1.9 1.1 0.9 0.5 1966 17.5 14.1 7.1 3.3 2.6 1.0 1967 4.0 3.3 2.3 1.5 1.2 0.7 1968 16.1 12.8 6.2 2.9 2.3 0.8 1969 8.9 7.1 4.5 2.1 1.6 0.6 1970 4.5 3.6 2.0 1.4 1.0 0.7 1971 5.4 4.5 2.5 1.8 1.3 0.7 1972 7.1 5.9 4.5 2.7 1.8 1.0 1973 16.6 13.3 6.6 3.2 2.4 1.0 1974 9.5 7.8 4.7 2.4 1.9 0.9 1975 24.5 19.7 10.6 5.1 3.7 1.2 1976 10.5 8.6 4.9 3.0 2.4 1.0 1977 2.4 2.1 1.6 1.3 1.2 0.6 1978 1.8 1.5 1.1 0.9 0.9 0.5 1979 7.6 6.2 4.1 2.5 1.8 1.0 1980 8.1 6.6 3.4 2.6 1.9 0.6 1981 4.6 3.7 2.0 1.2 1.0 0.6 1982 3.3 2.7 1.5 0.9 0.7 0.5 1983 5.8 5.0 3.3 2.2 1.9 0.8 1984 3.4 2.8 1.5 1.1 1.0 0.6 1985 5.6 4.5 2.3 1.5 1.4 0.6 1986 5.1 4.1 2.3 1.3 1.0 0.7 1987 8.5 7.0 5.6 2.8 2.4 0.9 1988 3.7 3.0 1.6 1.0 0.7 0.5 1989 8.3 6.7 3.7 1.9 1.8 0.8 1990 6.1 5.0 2.8 1.8 1.7 0.8 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.0 24.5 19.7 10.6 5.1 3.7 1.2

### 15

0.1 17.5 14.1 7.1 3.3 2.6 1.0 0.1 16.6 13.3 6.6 3.2 2.4 1.0 0.1 16.1 12.8 6.2 3.0 2.4 1.0 0.2 10.5 8.6 5.6 2.9 2.4 1.0 0.2 9.5 7.8 4.9 2.8 2.3 1.0 0.2 8.9 7.1 4.7 2.7 1.9 0.9 0.3 8.5 7.0 4.5 2.6 1.9 0.9 0.3 8.3 6.7 4.5 2.5 1.9 0.8 0.3 8.1 6.6 4.1 2.4 1.8 0.8 0.4 7.6 6.2 3.7 2.3 1.8 0.8 0.4 7.1 5.9 3.4 2.2 1.8 0.8 0.4 6.7 5.5 3.3 2.1 1.7 0.8 0.5 6.5 5.3 2.9 1.9 1.7 0.7 0.5 6.1 5.1 2.8 1.9 1.7 0.7 0.5 5.9 5.0 2.7 1.8 1.6 0.7 0.5 5.8 5.0 2.7 1.8 1.4 0.7 0.6 5.6 4.5 2.5 1.5 1.3 0.7 0.6 5.4 4.5 2.3 1.5 1.2 0.7 0.6 5.1 4.1 2.3 1.5 1.2 0.6 0.7 4.6 3.7 2.3 1.4 1.2 0.6 0.7 4.5 3.6 2.0 1.4 1.1 0.6 0.7 4.0 3.3 2.0 1.3 1.0 0.6 0.8 3.7 3.1 1.9 1.3 1.0 0.6 0.8 3.6 3.0 1.9 1.2 1.0 0.6 0.8 3.4 2.8 1.6 1.1 1.0 0.5 0.9 3.3 2.8 1.6 1.1 0.9 0.5 0.9 3.3 2.7 1.5 1.0 0.9 0.5 0.9 2.4 2.1 1.5 0.9 0.7 0.5 1.0 1.8 1.5 1.1 0.9 0.7 0.4 0.1 16.6 13.3 6.6 3.2 2.4 1.0 Average of yearly averages : 0.7

Inputs generated by pe5.pl
- Novemeber 2006 Data used for this run: Output File: PATomG_DW_15
- 07 Metfile: w14751.dvf PRZM scenario: PAtomatoSTD.txt EXAMS ir298.ex

### 16

environ ment file: v Chemica l Name: Pyraclostrobin Descripti on Variable

Name Value Units Comments Molecul ar weight mwt 388 g/mol Henry's Law Const. henry 1.30E - 07 atm - m^3/mol Vapor Pressure vapr 6.88E - 07 torr Solubilit y sol 2.7 mg/L Kd Kd mg/L Koc Koc 9304 mg/L Photolys is half
life kdp 0.11 days Half
- life Aerobic Aquatic Metaboli sm kbacw 45.1 days Halfife

Anaerob ic Aquatic Metaboli sm kbacs 12.1 days Halfife

Aerobic Soil Metaboli sm asm 247.2 days Halfife
Hydrolys is: pH 7 0 days Half
- life Method: CAM 2 integer See PRZM manual Incorpor ation Depth: DEPI 0 cm Applicati on Rate: TAPP 0.22 kg/ha Applicati on Efficienc y: APPEFF 0.99 fraction

### 17

Spray Drift DRFT 0.064 fraction of application rate applied to pond Applicati on Date Date 15 - 07 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 0.2 kg/ha Interval 2 interval 14 days Set to 0 or delete line for single app. app. rate 2 apprate 0.2 kg/ha Interval 3 interval 7 days Set to 0 or delete line for single app. app. rate 3 apprate 0.2 kg/ha Interval 4 interval 14 days Set to 0 or delete line for single app. app. rate 4 apprate 0.2 kg/ha Interval 5 interval 7 days Set to 0 or delete line for single app. app. rate 5 apprate 0.2 kg/ha Record 17: FILTRA

IPSCND 1 UPTKF Record 18: PLVKRT

PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR Reservoi

r Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)

### 18

**Model SCIGROW** SCIGROW VERSION 2.3 ENVIRONMENTAL FATE AND EFFECTS DIVISION OFFICE OF PESTICIDE PROGRAMS U.S. ENVIRONMENTAL PROTECTION AGENCY

SCREENING MODEL FOR AQUATIC PESTICIDE EXPOSURE SciGrow version 2.3 chemical:Pyraclostrobin time is 2/10/2013 7:50:44

------------------------------------------------------------------------ Application Number of Total Use Koc Soil Aerobic rate (lb/acre) applications (lb/acre/yr) (ml/g) metaboli sm (days)

------------------------------------------------------------------------ 0.156 6.0 0.936 9.00E+03 161.0

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

groundwater screening cond (ppb) = 6.18E - 03 ************************************************************************ **Model PRZM_GW**