UN I TED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

O FF ICE OF CHE M ICA L S AFE TY AND PO L L U T I O N PR E V ENTI ON
PC Code: 035201 DP Barcode: 427440 DATE: August I 3 , 20 15
MEMORANDUM

SUBJECT:
FROM:

THRU:

TO:

OVERVIEW Dicrotophos: Revised Drinking Wate r Assessment fo r Registration Review
Andrew Shelby , Physical**Sc entist** **~ ~** **-13-** 

### isE n vironmental Risk Branch 6 Environmental Fate and Effects Divison (7507P)
Mark Corb in , Branch Chief

. 

# , / A() 

# U '15-\3·\:S Will.iam P. Ecke l.Ph.D , Sen i o r Scie n ce

# Adviso**~ //~**  _ ._ 

## £)C> / ()rg / 13 /;( Environmenta l Risk Branch 6 ./**W~~() ,** **~** E n viro nm enta l Fate and Effects Di viso n (7507P)
Thurston Morton , Ri sk Assessor Charles Sm ith , Branch Ch i ef Risk Assessment Branch 4 Hea lth Effects Division (7509P)
Khue Nguyen, Chemica l Review Manager Neil Ande r son , Branch Chief Risk Management and Implementation Branch 1 Pest i c id e Re-Evaluation Division (7508 P )

The E n v ironm en t a l Fate and Effects Division (EFED) has completed a Revised Drinking Water Assessment for the registration r ev i ew of dicrotophos. This updates th e July 14, 20 1 4 document (DP 398772) to respond to and in corporate, as appropr i ate , public comments from th e dicrotophos registrant. Dicrotophos is registered for use on cotton and o rn ame nt al trees. For cotton, th e maximum
s in gle app li cation rate fo r the broadcast us e is 0.5 pounds of act i ve ingredient per acre (lb a. i ./ A),2 and the maximum seasonal application rate is 1.2 lb s a
. i

. /A ; f or ornamental tree applica tion, which is administered through tree injection , the calculated maximum single application rate is 0.228 lb a.i./ A

. There is no seasonal maximum application for the tree injection use. This drinking water assessment uses maximum rates and considers typical rates , al though concentrations reported in the monitoring data exceed the modeled estimated drinking water concentrations ( EDWC ) when typical application rates are used

. A single study is used estimate the aerobic soil metabolism input parameter , therefore the half

life was multiplied by three to conservatively derive the parameter

. This input parameter is intended to represent the many varieties of soil and microbial communities that may metabolize di crotophos at differing rates. Additional aerobic soil metabolism data ( EFED typically requests this data for three or more soil types ) , would allow for better characterization of degradation behavior and reduce uncertainty in the modeled results.
This revised assessment changes the cotton percent cropped area (PCA) from 33% to 21% based on updated guidance (EPA, 2014a), incorporates application rate and application date recommendations made by the Biological and Economic Analysis Division (EPA, 2014 b ) a nd addresses comments on the original assessment made by Stone Environmental on behalf of the registrant, AMVAC (MRID 49582601). Registrant comments are addressed in more detail in Appendix A

. SWCC (Surface Water Concentration Calculator v1.106 ) modeling runs producing the highest EDWCs are presented in Appendix B

. Based on modeling results from the Texas Cotton scenario , the maximum estimated surface water exposure concentrations for dicrotophos and assuming maximum application rates for current uses are: 8.75 μg/L for the 1 in 10 year annual peak concentration 0. 507 μg/L for the 1

- in

- 10 year annual average , and 0. 306 μg/L for the 30 year annual average
Based on ground water modeling results ( PRZM

- GW ), the maximum estimated groundwater exposure concentration from six vulnerable scenarios for dicrotophos is 0.0003 μg/L for acute and chronic exposure based on post breakthrough average
. Since the predicted concentrations in ground water are well below those calculated for surface water, su rface water exposures are the driver for dicrotophos drinking water exposure

. Fate and Transport Characterization
The most significant degradation pathway for dicrotophos is aerobic soil metabolism (half

- life = 3 days; MRID 160826 ). Dicrotophos is more persistent to hydrolysis with a half

- life of 72 days (MRIDs 160823 ). Dicrotophos hydrolyzes in pH 7 water with a half

- life of 72 days (MRID 160824 ). Dicrotophos is mobile with adsorption coefficients (K d ) ranging from of 0. 1 to 3.58 mL/g ( FAO Classification; MRID 160828 ). A full summary of adsorption/ desorption data can be found in the Dicrotophos RED (EPA 2006)

. It is not appropriate to use K OC to characterize the mobility of dicrotophos because adsorption coefficients do not sufficient l y correlate with soil organic carbon content. Use of K d rather than K OC is consistent with previous assessments.3 However, adsorption strongly correlates with clay content (r 2 = 0.92). Monitoring Data Surface water monitoring data from the USGS National Water

- Quality Assessment Program (NAWQA) and USDA’s Pesticide Data Program for dicrotophos indicate 5 7 detections in seven states (Colorado, Georgia, Louisiana, Minnesota, Mississippi, North Carolina, an d Texas) from approximately 8,500 samples . The peak detection of 6.83 parts per billion occurred in a cotton growing area of Washington County, Mississippi in 2005 . All other detections were for concentrations less than 0.3 parts per billion. No NAWQA s urface water monitoring has occurred in northwest Texas, one of the largest concentrated cotton growing areas in the United States. No groundwater monitoring data for dicrotophos was found. Drinking Water Exposure Modeling The modeling of the surface water and groundwater concentrations for the cotton use pattern follows standard modeling practices outlined in EFED’s Input Parameter Gu idance (EPA 2009) and is consistent with previous assessments

. Surface water exposure fo r the tree injection use pattern is not quantitatively modeled as is discussed further in the paragraph below

. The tree injection u se is not expected to be concentrated to the extent that it will affect surface water intakes for drinking water. In a letter dated June 18, 2012, the registrant characterizes the Great Lakes region , an area of more than 386,000 mi 2 , to have the highest use of the dicrotophos tree injection with an estimated 3,600 to 7,200 trees being treated over that area with 700 to 800 pounds of active ingredient. Nationally, 2,500 to 2,600 pounds of active ingredient are used for tree injection on an annual basis. This compares to 900,000 pounds of active ingredient used nationally for cotton on an annual basis

. The percent cropped area (PCA) for the cotton use pattern has been well characterized and estimated to be a maximum of 21 % of any watershed upstream from a drinking water intake (EPA, 2014a ) . A similar calculation has not been made for a tree injection use pattern , but based on the referenced information submitted by the registrant, the proportion of a given watershed treated for the tree injection use is not expected to approach the proportion determined for cotton. For this reason, the tree injection use pattern is not modeled for surface water exposure.
T he tree injection use is considered for groundwater , however, because exposure is not dependen t on PCA adjustment factors

. Dicrotophos tree injection use is labeled for 16 varieties of tree and 25 insect pests. Though modeling tree injection uses is not unprecedented, this use does not follow the typical modeling paradigm and therefore, conservati ve assumptions must be made to derive EDWCs. The method used to assess tree injection of dicrotophos has been used previously in EFED risk assessments in an assessment on emamectin (D351736)

. Aquatic exposures could occur from the chemical entering soi l environments and subsequently entering aquatic environments. This could occur if the chemical is translocated primarily to the leaves, and the leaves fall to the soil and decompose. It is conservatively assumed that the total mass of the chemical appli ed to a tree via injection is applied directly to soil. For dicrotophos the amount4 of formulation injected is dependent on the tree size. A 72 inch diameter brea st height (DBH) tree is conservatively assumed. Per label instructions, this number is divided by two to determine number of capsules to be injected. Tree injection capsules are small, disposable containers filled with formulated product delivered through a small tube via a hole drilled into the active xylem of the affected tree. Capsules range in size from one to three mL though the three mL capsule will be conservatively assumed for modeling. Assuming one tree per acre is treated , the application rate is:
72 in

. DBH 1 × 1 capsule 2 in

. DBH × 3 mL 1 capsule × 1 gallon 3785 mL × 8 lbs a
. i

. 1 gallon = 0

. 228 lbs a
. i

. / AA
This resulting application rate is less than half the maximum single application rate for the cotton use pattern and is also representative of many smaller trees on a given acre ( e.g. , six trees of 12 inch DBH) . Given this and the previous discussion regarding surface water exposure , EDWCs generated for the cotton use pattern are protective for the tree injection use pattern for both surface water and groundwater exposure s . Parameters for the derivation of Tier II surface water concentrations and the Tier I groundwater concentration for cotton are as follows:
Table 1
. SWCC and PRZM
- GW input parameter values for dicrotophos modeled for u se on cotton (which is protective of the tree injection use )

PARAMETER (units) VALUE(S) SOURCE COMMENT Application Rate ( lb a.i./A) ) See Table 2 Maximum Rates Emergence to pre

- bloom = 0.2 lb a.i./ A 1 st bloom to 30 days pre

- harvest = 0.5 lb a.i./ A with two applications allowed

Number of Applications 3 Interval between Applications (days) 14 Labeled interval for cotton. Assumed interval for tree injection based on label language : “Do not inject trees within two weeks of any other spray or soil chemical treatment” (Reg. No. 7946

- 11) Molecular weight (g/mol) 237.19 Henry’s Law Constant (atm

m 3 /mol) 3.13 x 10

- 11 Dicrotopho s RED Vapor Pressure (torr) 7 x 10

- 5 435004015 PARAMETER (units) VALUE(S) SOURCE COMMENT Solubility in Water @ 20 O C, (mg/L or ppm) 11,990 43603202, 43603201
Soil Partition Coefficient (mL/g) K d = 1.24 160828 Lowest non

- sand K d is used because adsorption does not correlate with organic carbon CAM (Chemical Application Method) 2 Cotton: foliar spray; emergence to 30 days pre

- harvest , unincorporated Depth of Incorporation (inches) 0

– Application efficiency (decimal) 0.95 Aerial application with no buffer to surface waters permitted on label
Spray drift fraction (decimal) 0.16

Percent Cropped Area (decimal) 0. 21 PCA Guidance Though the use pattern includes tree injections, the cotton only PCA adjustment factor is used because cotton and tree injection uses are spatially and temporally segregated. 1 Application date (day/month) Variable (see Table 2 ) Application dates informed by BEAD Hydrolysis Half

- life (days) 72 160823 Aqueous Photolysis Half

- life @ pH 7 (days) Stable 160824
Aerobic Aquatic Metabolism Half

- life (days) 16.2 2X aerobic soil metabolism parameter per Input Parameter Guidance 1 Anaerobic Aquatic Metabolism Half

- life (days) 48 160827 A naerobic soil metabolism half

- life = 8 days. 3X half

- life due to single half

- life value and 2X for estimating an aquatic half

- life with a soil half

life per Input Parameter Guidance 1

. Aerobic Soil Metabolism Half

life (days) 8.1 160826 Because only one half

- life is available, 3X is used per Input Parameter Guidance 1
1 Development of Community Water System Drinking Water Intake Percent Cropped Area Adjustment Factors for use in Drinking Water Exposure Assessments: 2014 Update . September 9, 2014. 2 “Input Parameter Guidance” refer s to Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides; Version 2.1 , October 22, 2009

.

Tier II surface water EDWCs were generated for uses on cotton with Mississippi , North6 Carolina, and Texas Cotton SWCC scenario s . Both BEAD recommended application d ates (Typical Rate

– BEAD dates) and dates with minimum retreatment intervals (Typical Rate

– 14 day interval) were used along with maximum rates and minimum retreatment i ntervals

. Application dates and t ypical rates were supplied by BEAD in a memo detailing application rates for many organophosphates (EPA, 2014 ).
Table 2
. Parameterization of application rates and application dates for SWCC modeling

SWCC Scenario Application rate and timing Application rates (lb a.i./A) Application date (1 st application) Application date (2 nd application) Application date (3 rd application) Mississippi Cotton Maximum Rate 1 st 0.2 ; 2 nd 0.5 ; 3 rd 0.5 27 June 11 July 25 July Typical Rate

- BEAD dates 0.28 27 June 27 July

-- Typical Rate

- 14 day interval 0.28 27 June 11 July

-- North Carolina Cotton Maximum Rate 1 st 0.2 ; 2 nd 0.5 ; 3 rd 0.5 29 June 13 July 27 July Typical Rate 0.22 29 June

-- -- Texas Cotton Maximum Rate 1 st 0.2 ; 2 nd 0.5 ; 3 rd 0.5 27 June 11 July 25 July Typical Rate

- BEAD dates 0.24 27 June 27 July

-- Typical Rate

- 14 day interval 0.24 27 June 11 July

--

Table 3
. Ranges of Tier II Estimated Drinking Water Concentrations (EDWCs) for surface water based on application of dicrotophos to cotton ( protective of the tree injection use )

SWCC Scenario Application rate and timing 1
- in
- 10
- year peak (ppb) 1
- in
- 10
- year 21 day average (ppb) 1
- in
- 10
- year annual average (ppb) Simulation average (ppb) Mississippi Cotton Maximum Rate 6.09 4.01 0.381 0.199 Typical Rate

- BEAD dates 3.21 1.67 0.193 0.0860 Typical Rate

- 14 day interval 4.49 2.45 0.204 0.0834
North Carolina Cotton Maximum Rate 7.73 4.94 0.507 0.306 Typical Rate 1.62 1.05 0.0901 0.0503
Texas Cotton Maximum Rate 8.75 4.63 0.430 0.222 Typical Rate

- BEAD dates 3.66 2.12 0.238 0.0934 Typical Rate

- 14 day interval 3.69 2.09 0.217 0.0839

The modeling of typical rates is performed for characterization and may be considered for quantitative purposes with the caveat that the values are not conservative in all cases. For instance, the typical rate 1

- in

- 10

- year peak EDWC for cotton in Mississi ppi is 3.21 to 4.49 ppb.7 However, monitoring data indicate that concentrations of 6.83 ppb occurred in Mississippi in 2005 when dicrotophos had the same use pattern and maximum application rates as modeled in this assessment. Though the next highest dete ction was less than 0.3 ppb, one detection is indicative that similar concentrations could occur in other surface waters or at the same site at a different time but are not recorded. This monitoring data is derived from a targeted effort on the Bogue Phal ia, a cotton predominant watershed, in which water samples were collected and dicrotophos concentrations were determined approximately every 14 days. Because pesticide concentrations vary depending on weather, application patterns and subsequent dissipati on, the likelihood of capturing the peak concentration of dicrotophos diminishes with a sampling interval of 14 days. All presented modeled applications reflect aerial applications though dicrotophos may also be applied through ground applications. Groun d applications reduces off

- site spray drift but application efficiency is increased thereby increasing pesticide residues in run off. Modeling ground applications as opposed to aerial applications reduces peak 1

- in

- 10

- year EDWCs by 2% to 5%.
Based on an analysis of a more complete monitoring dataset for atrazine, the average bias factor on a sampling interval of 14 days for estimating a 60

- day rolling mean was approximately 4 with a 95% confidence interval of approximately 7 (SAP, 2012). Due to differenc es in exposure window and the variability in field conditions, these bias factors cannot be directly applied to dicrotophos monitoring data. However, the bias factors illustrate the uncertainty a ssociated with identifying 6.83 ppb as the highest concentra tion occurring in dicrotophos use areas. Given these uncertainties , EDWCs derived from typical rates model simulations should be used with caution and the awareness that it does not conservatively represent dicrotophos concentrations in all documented ins tances.
Tier I ground water EDWCs were generated for the cotton use using PRZM

- GW . In the case of a Tier I assessment, the cotton use is protective of the tree injection use since the application rate is highest. For Tier 1 PRZM

- GW, all six standard scenarios we re run as the scenarios represent a range of vulnerable ground water conditions that may occur across the United States , an d dicrotophos is registered for national use

. The highest groundwater concentration for acute and chronic EDWCs is 0.0 00 3 ppb generated from the Florida Citrus scenario in PRZM

- GW . This concentration is 1,600 times lower than the 30

- year annual average EDWC for surface water.8 References
EPA. 2006. Interim Reregistration Eligibility Decision for Dicrotophos Case No. 0145 . Office of Pesticide Programs. Special Review and Registration Division. July 31, 2006
EPA. 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. Environmental Fate and Effect s Divis ion. Office of Pesticide Programs. EPA. 2014a. Development of Community Water System Drinki ng Water Intake Percent Cropped Area Adjustment Factors for use in Drinking Water Exposure Assessments: 2014 Update. Environmental Fate and Effects Division. Office of Pesticide Programs. September 9, 2014 EPA, 2014 b

. Information to support registration review of dicrot ophos: cotton crop phenology in the southern U.S., recent dicrotophos use patterns, and potential alternative insecticide s Biological and Economic Analysis Division. Office of Pesticide Programs. 2014
SAP. 2012. FIFRA SAP Meeting Held June 12

- 14, 2012 on Sc ientific Issues Associated with for the Problem Formulation for the Reassessment of Eco logical Effects from the Use of Atrazine9 APPENDIX A

– Stone Environmental Comments Considered and Justification for not incorporating The July 14, 2014 dicrotophos drinking water assessment (DP 398772) was posted in the public docket at regulations.gov (EPA

- HQ

- OPP

- 2008

- 0440

- 00 23 ) for a 60

- day public comment period. AMVAC Chemical Corporation, the dicrotophos registrant, submitted public comments to the docket on December 1, 2014 (EPA

- HQ

- OPP

- 2008

- 0440

- 0030), including comments related to drinking water. Subsequently on March 2 , 2015 AMVAC submitted its own drinking water assessment for dicrotophos, conducted by Stone Environmental (MRIDs 49582600

– 01). This revised drinking water assessment for dicrotophos incorporates some of the comments from MRID 49582601. The following parameters are updated or corrected: 1) In SWCC modeling, f oliar application is specified instead of ground application. Ground application was parameterized in error in the original drinking water assessment , and is now corrected. 2) The cotton PCA is updated from 33% (as specified in 2012 guidance) to 21% (as specified in 2014 guidance). The original drinking water assessment was finalized prior to the release of the updated guidance. Because the drinking water assessment is being revised in 2015, th e updated PCA is incorporated. The following comments from AMVAC/Stone were considered but not incorporated in updated SWCC modeling and EDWCs for the following reasons: 1) Aerial buffers of 150 feet and ground buffers of 25 feet to surface waters are not included in EDWC calculation s because they are not required on all dicrotophos end

- use labels. EFED assesses risk based on the least restrictive label based on the assumption that an applicator, when given the choice, will acquire the product with the least restrictions associated with it. However, if the registrant chose to require these buffers on all current dicrotophos product labels, 1

- in

- 10

- year 21

- ay average EDWCs could be expected to be reduced by 5% to 6%. 2) The foliar half

- life parameter in SWCC is maintained as “ stable ” even though AMVAC/Stone provide d a rationale for a foliar half

- life of 3 days based field studies in cotton. However, the studies cited by AMVAC/Stone only address dissipation of residues and do not specifically address d egradation. The foliar half

- life parameter only represents degradation that occurs on the leaf surface. Dissipation processes, such as foliar wash

- off during precipitation events, are included in SWCC and are distinct from the foliar half

- life. Therefor e, foliar half

- life estimates based on field dissipation study results would overestimate the amount of dissipation occurring and cannot be used for SWCC parameterization. 3) Dicrotophos is registered for use on cotton across the United States without ge ographic restriction s on the end

- use product labels

. Alt hough the North Carolina cotton scenario is representative of a region with a cotton only PCA of 8%, the national 21% PCA is10 applied because the North Carolina, Texas, and Mississippi cotton scenario s are considered together to represent drinking water concentrations nationally. Additionally, use of dicrotophos for tree injections is not considered in this approach. Alt hough tree injection usage is believed to be small, use of the highest cotton PCA of 21% is conservative in this regard while the Delta and North Carolina cotton PCAs are not (20% and 8%, respectively). 4) BEAD estimates of application dates, based on USDA, National Cotton Council, and proprietary data, are used in this assessment in favor of those provided by AMVAC/Stone because the date selections are supported by a variety of accepted sources.11 APPENDIX B
- SWCC output file producing highest 1
- in
- 10
- year 21 day average EDWC Variable Volume Water Model, SWCC Compatible Version

******************************************* Performed on: 7/ 6/2015 at 16:45
Peak 1

- in

- 10.0 = 8.75 ppb Chronic 1

- in

- 10.0 = 0.430 ppb Simulation Avg = 0.222 ppb 4

- d avg 1

- in

- 10.0 = 7.52 ppb 21

- d avg 1

- in

- 10.0 = 4.63 ppb 60

- d avg 1

- in

- 10.0 = 2.19 ppb 90

- d avg 1

- in

- 10.0 = 1.58 ppb
Benthic Pore Water Peak 1

- in

- 10.0 = 2.09 ppb Benthic Pore Water 21

- d avg 1

- in

- 10.0 = 2.00 ppb Benthic Conversion Factor = 1.61

- Pore water (ug/L) to (total mass, ug)/(dry sed mass,kg) Benthic Mass Fraction in Pore Water = 0.230
YEAR Peak 4

- day 21

- day 60

- day 90

- day Yearly Avg Benthic Pk Benthic 21

- day

1 4.92E+00 4.34E+00 3.25E+00 1.73E+00 1.59E+00 4.33E

- 01 1.59E+00 1.54E+00 2 1.74E+01 1.49E+01 8.55E+00 3.84E+00 2.70E+00 7.36E

- 01 4.02E+00 3.82E+00 3 8.31E

- 01 7.20E

- 01 5.02E

- 01 3.16E

- 01 2.68E

- 01 8.01E

- 02 2.25E

- 01 2.82E

- 01 4 8.27E

- 01 7.17E

- 01 4.99E

- 01 3.64E

- 01 2.90E

- 01 7.88E

- 02 1.94E

- 01 1.81E

- 01 5 1.25E+00 1.08E+00 6.45E

- 01 4.91E

- 01 3.69E

- 01 9.60E

- 02 3.32E

- 01 3.16E

- 01 6 7.74E+00 6.70E+00 4.58E+00 2.19E+00 1.57E+00 4.01E

- 01 1.98E+00 1.87E+00 7 2.43E+0 0 2.16E+00 1.42E+00 7.92E

- 01 6.46E

- 01 1.74E

- 01 6.73E

- 01 6.50E

- 01 8 2.17E+00 1.92E+00 1.42E+00 8.24E

- 01 7.99E

- 01 2.18E

- 01 6.36E

- 01 6.10E

- 01 9 8.86E+00 7.61E+00 4.64E+00 2.15E+00 1.57E+00 4.08E

- 01 2.10E+00 2.01E+00 10 1.01E+00 8.73E

- 01 5.29E

- 01 3.87E

- 01 3.45E

- 01 9.73E

- 02 2.76E

- 01 2.64E

- 01 11 3.11E+00 2.76E+00 1.87E+00 1.05E+00 7.53E

- 01 1.91E

- 01 7.42E

- 01 7.12E

- 01 12 1.35E+00 1.18E+00 8.89E

- 01 5.14E

- 01 3.78E

- 01 9.51E

- 02 3.26E

- 01 3.11E

- 01 13 1.38E+00 1.21E+00 9.19E

- 01 5.37E

- 01 4.33E

- 01 1.38E

- 01 3.36E

- 01 3.24E

- 01 14 4.12E+00 3.61E+00 2.48E+00 1.28E+00 9.35E

- 01 2.43E

- 01 1.03E+00 9.83E

- 01 15 3.52E+00 3.11E+00 2.10E+00 1.21E+00 9.36E

- 01 2.40E

- 01 1.21E+00 1.16E+00 16 1.95E+00 1.72E+00 1.35E+00 8.86E

- 01 8.14E

- 01 2.23E

- 01 6.62E

- 01 6.26E

- 01 17 3.04E+00 2.64E+00 1.86E+00 8.85E

- 01 6.70E

- 01 2.06E

- 01 8.37E

- 01 8.02E

- 01 18 4.37E+00 3.78E+00 2.22E+00 1.12E+00 8.08E

- 01 2.08E

- 01 9.84E

- 01 9.38E

- 01 19 1.42E+01 1.25E+01 8.88E+00 4.50E+00 3.14E+00 7.90E

- 01 4.19E+00 3.99E+00 20 7.94E

- 01 6.77E

- 01 4.67E

- 01 3.25E

- 01 2.91E

- 01 8.17E

- 02 1.80E

- 01 1 .69E

- 01 21 2.41E+00 2.09E+00 1.25E+00 6.77E

- 01 7.16E

- 01 2.00E

- 01 6.65E

- 01 6.34E

- 01 22 8.24E

- 01 7.12E

- 01 4.96E

- 01 2.98E

- 01 2.29E

- 01 6.07E

- 02 1.43E

- 01 1.35E

- 01 23 2.17E+00 1.90E+00 1.43E+00 9.42E

- 01 6.74E

- 01 1.71E

- 01 6.68E

- 01 6.12E

- 01 24 8.54E

- 01 7.38E

- 01 4.98E

- 01 3.07E

- 01 2.40E

- 01 6.49E

- 02 1.50E

- 01 1.43E

- 0112 25 1.47E+00 1.27E+00 7.92E

- 01 4.03E

- 01 4.28E

- 01 1.35E

- 01 3.66E

- 01 3.54E

- 01 26 2.32E+00 2.03E+00 1.25E+00 6.07E

- 01 5.51E

- 01 1.57E

- 01 5.20E

- 01 5.00E

- 01 27 4.70E+00 4.10E+00 2.54E+00 1.22E+00 1.14E+00 3.30E

- 01 1.19E+00 1.14E+00 28 9.44E

- 01 8.22E

- 01 6.52E

- 01 4.43E

- 0 1 3.28E

- 01 8.46E

- 02 2.63E

- 01 2.41E

- 01 29 2.15E+00 1.88E+00 1.12E+00 6.14E

- 01 5.04E

- 01 1.35E

- 01 5.71E

- 01 5.42E

- 01 30 3.37E+00 2.91E+00 1.95E+00 9.55E

- 01 6.78E

- 01 1.74E

- 01 1.09E+00 1.04E+00 ************************ ****************************************************** ********************** Effective compartment halflives averaged over simulation duration: washout halflife (days) = 104.602571075456 water col metab halflife (days) = 20.8950 713136149 hydrolysis halflife (days) = 72.0050250173948 zero photolysis 0 zero volatility 0 total water col halflife (days) = 14.0240475830529
zero burial 0 benthic metab halflife (days) = 61.9113224107107 benthic hydrolysis halflife (days) = 313.064356843458 total benthic halflife (days) = 51.6892945440851 ************************************************************* ********** Fractional Contribution of Transport Processes to Waterbody & Total Mass (kg):
Due to Runoff = 0.7371 17.63 Due to Erosion = 0.0112 0.2689 Due to Drift = 0.2516 6.018 *************** ******************************************************** Flow in/out Characteristics of Waterbody: Average Daily Runoff Into Waterbody (m3/s) = 1.105353439886830E

- 002 Baseflow Into Waterbody (m3/s) = 0.000000000000000E+000 Average Daily Flow Out of Waterbody (m3/s) = 1.105353439886858E

- 002 *********************************************************************** Inputs:

31.00 = oc partitioning coefficient 16.20 = water column half Life 25.00 = referen ce temp for water column degradation 48.00 = benthic Half Life 25.00 = Reference temp for benthic degradation 2.000 = Q ten value 0.000 = photolysis half life 40.00 = reference latitude for photolysis study 72.00 = hydrolysis half life 237.2 = molecular wt 0.7000E

- 04 = vapor pressure 0.1199E+05 = solubility13 0.1728E+07 = field area 0.5260E+05 = water body area 2.740 = initial depth 2.740 = maximum depth 3 1=vvwm, 2=usepa pond, 3 = usepa reservoir, 4 = const vol no flow, 5 = const vol w/flow F T = burial, else no burial 0.1000E

- 07 = mass transfer coefficient 0.5000 = PRBEN 0.5000E

- 01 = benthic compartment depth 0.5000 = benthic porosity

1.350 = benthic bulk density 0.4000E

- 01 = OC frcation in benthic sediment 5.000 = DOC in benthic compartment 0.6000E

- 02 = benthic biomass

1.190 = DFAC 30.00 = SS 0.5000E

- 02 = chlorophyll 0.4000E

- 01 = OC frcation in water column SS 5.000 = DOC in water column 0.4000 = biomass in water column FRACTION AREA CROPPED = 0.210000000000000