MEMORANDUM

DATE:	July 22, 2010

SUBJECT:	Estimated Drinking Waters Concentrations (EDWCs) of
Triflusulfuron-methyl for the Use in the Human Health Risk Assessment:
New Use (IR-4) of the Chemical on Garden Beets (PC Code 129002; DP
Barcode D373494)

TO:		Laura Nollen, Risk Manager Reviewer

		Barbara Madden, Review Manager #5

		Daniel (Dan) Rosenblatt, Chief

		Minor Use Team

Risk Integration, Minor Use, and Emergency Response Branch

		Registration Division (7505P)

AND:		Elizabeth Holman, Chemist, Risk Assessor

Linnea Hansen, Risk Assessor

Christina Swartz, Chief

		Registration Action Branch II

		Health Effects Division (7509P)

		Environmental Risk Branch V

		Environmental Fate and Effects Division (7507P)

THRU:	Mah T. Shamim, Ph.D., Chief

Environmental Risk Branch V

		Environmental Fate and Effects Division (7507P)

This memo presents the surface and ground Estimated Drinking Water
Concentrations (EDWCs) for triflusulfuron-methyl, calculated using the
Tier 2 aquatic models PRZM/ EXAMS and the Tier 1 aquatic model SCI-GROW,
respectively, for use in the human health risk assessment.  The
registrant is proposing the use of the chemical on garden beets.  Based
on an inspection of the new use of triflusulfuron-methyl, it was found
that sugar beet still represents the scenario with the highest exposure.
 The previously modeled use covers the new use.  Therefore, the drinking
waters assessment results do not change from the previous ones.  For
electronic copy of the previous drinking waters assessment refer to DP
Barcode D260078 (Attachment A, see page 3 of this document).

The EDWCs for triflusulfuron-methyl, calculated using the Tier 2 models
PRZM/ EXAMS (surface water) and the Tier 1 model SCI-GROW (ground water)
for use in the human health risk assessment were as follows:  In surface
waters, the acute value is 0.42 ppb and the chronic value is 0.005 ppb. 
The groundwater screening concentration of triflusulfuron-methyl
suitable for both acute and chronic exposures is 0.50 ppb (Table 1). 
Should any questions arise, please, contact EFED.

Table 1.  Estimated Drinking Water Concentrations (EDWCs) for human
health risk assessment for aerial application of triflusulfuron-methyl
on sugar beets



Chemical	

Acute Surface Water PRZM/EXAMS (ppb)	

Chronic Surface Water  PRZM/EXAMS (ppb)	

Acute and Chronic Ground Water  SCI-GROW (ppb)*

Triflusulfuron-methyl	0.42	0.005	0.50



Identification of data gaps:

Additional aerobic and anaerobic soil studies and aerobic and anaerobic
aquatic metabolism studies would decrease substantially the
uncertainties in the fate database.

Use Characterization

DuPont™ UpBeet® Herbicide (EPA Reg. No. 352-569).  DuPont™ UpBeat®
is a water dispersible granule (dry flowable) formulation, containing
50% active ingredient.

  SEQ CHAPTER \h \r 1 Table 2.  Summary of use information for
triflusulfuron-methyl, based on the proposed label for DuPont™
UpBeet® Herbicide (EPA Reg. No. 352-569).  The new use is shaded yellow
and bolded.

USE	SINGLE  APP. RATE   (lb a.i./A)	NUMBER OF APPS.	SEASONAL APP. RATE
(lb a.i./A)	INTERVAL BETWEEN APPS. (days)	APP. METHOD	INCORP. DEPTH
(inches)	PHI

Garden beets	0.0156	3	0.0469	NS1	G or A2	02	602

Sugar beets (includes those grown for seeds)	0.0156-0.0313; 0.003913	2-3
0.0781	5	G or A	0	60

Belgian Endive/Chicory	0.0156	2-3	0.0469	5	G or A2	02	60

1 Not specified.  Apply at 2 to 4 leaf stage; additional applications at
4 to 6 and 6 to 8 leaf stages.

2 Per reference to Section 3 label in the Supplemental Label and
instructions provided in the package.

3 Microrate applications (make a minimum of 3 applications).Attachment
A.  Electronic copy of previous DWA for Triflusulfuron-methyl

                   UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                                          WASHINGTON, D.C. 20460

                                                                        
                                     OFFICE OF

                                                                        
                                                                     
PREVENTION, PESTICIDES AND

                                                                        
                                                                        
         TOXIC SUBSTANCES                                               
                            			

December 20, 1999

DP Barcode:	D260078

PC Code:	129002

MEMORANDUM

Subject:	Triflusulfuron-Methyl Tier II Estimated Environmental
Concentrations for Use in the Human Health Drinking Water Risk
Assessment

Product: UpBeet Water Dispersible Granule (50% Active); 352-569

Registrant: DuPont

To:	Michael Doherty  

Registration Action Branch 2

Health Effects Division (7509C)

Vickie Walters, Product Manager

Herbicide Branch

Registration Division (7505C)

From:	Sid Abel, Environmental Scientist

Fate and Monitoring Branch

Environmental Fate and Effects Division (7507C)

Thru:	Betsy Behl, Chief

     	Fate and Monitoring Branch

Environmental Fate and Effects Division (7507C)

This memorandum transmits the Tier II Estimated Environmental
Concentrations (EECs) for the tolerance reassessment of
triflusulfuron-methyl applied to sugarbeets using the Index Reservoir
(IR) and Percent Crop Area (PCA) modifications to PRZM and EXAMS.  These
results do not include EECs for any of triflusulfuron-methyl’s known
degradates.  Should HED determine that there is a need for a separate
assessment for toxicologically significant degradates, please contact
Sid Abel (305-7346) as soon as possible.



Summary and Conclusions

Triflusulfuron-methyl may be found in surface water used as a source of
drinking water at peak concentrations up to 0.42 µg/L and on a
long-term basis (mean) at 0.005 µg/L from use on sugarbeets in
Minnesota.  Ground water concentrations, independent of the use area,
may be found at up to 0.5 µg/L; peak and mean concentrations. 
Triflusulfuron-methyl will not persist in the environment (accumulate
between repeated yearly applications) due to its short initial half-life
(bi-phasic) and hydrolytic half-life at environmental pH’s.  The low
adsorption coefficients may facilitate triflusulfuron’s leaching to
ground water under favorable conditions (shallow depth to groundwater,
coarse soils, or soils with significant preferential flow). Due to
triflusulfuron-methyl’s structure and physical properties, it is not
likely to be significantly affected by common treatment methods employed
at most community water systems (Faust, 1998). 

Triflusulfuron-methyl is currently registered for use on sugarbeets. 
Estimated environmental concentrations for sugarbeets are provided Table
1. These estimated values are recommended for use in the drinking water
assessment.

 Table 1.  Recommended Surface and Ground Water Concentrations ( µg/L)

Agricultural Setting	

Surface Water Concentrations	

Ground Water Concentrations



Sugarbeets Grown in Minnesota	

Peak	

Mean	

0.50

	

0.42	

0.005

	

Environmental Fate Summary

Triflusulfuron-methyl is not a very persistent sulfonylurea herbicide. 
The principle pathway of dissipation in the environment is through
aerobic and anaerobic metabolism and to a lesser degree hydrolysis. 
Direct photolysis on soil and in water is not a very important pathway,
but indirect photolysis may play a minor role in its degradation on
soils.  Biotically, Triflusulfuron-methyl degradation follows a
bi-phasic pattern with an approximate soil half-life of 6 days
initially, followed by a secondary half-life of approximately 170 days
in aerobically incubated soil.  Under anaerobic soil conditions,
triflusulfuron-methyl degraded with a half-life of 20 days. 
Triflusulfuron-methyl is mobile in all soils tested; Kd’s less than
1.3.  However, the parent was not detected below 14 inches in the two
field dissipation studies and decreased in concentration over the period
of the study indicating biotic degradation.  Sorption was not well
correlated to organic matter, but was better correlated to the soil pH.

Triflusulfuron-methyl degrades through cleavage of the sulfonylurea
bridge to form degradates containing either the triazine or phenyl ring.
 The principle degradates seen in the laboratory studies is methyl
saccharin and various triazine amines.  Methyl saccharin is more mobile
than the parent with Kd’s all less than 1.0 (KOC’s <25).  In several
of the soils, binding was so low that analysis could not be performed to
determine the extent of binding.  The half-life of methyl saccharin is
50-days under aerobic conditions and further degrades via
mineralization.  The other major degradates, triazine-amines, are less
mobile than the parent.  Among the triazine-amines, mobility increases
with a higher degree of demethylation.  The bis-NDM-triazine amine is
the most mobile with Kd’s up to 3.72 (KOC’s <220) and the least
mobile, triazine-amine, had Kd’s up to 10 (KOC’s <2175).  For
NDM-triazine-amine, Kd’s were up to 4.88  (KOC’s <300). The
half-life of triazine amine is approximately 40 days and further
degrades by demethylation.  Both degradates were detected up to the
36-inch segment in one or both of the field dissipation studies. 
Concentrations of methyl saccharin and triazine amine were very similar
during the studies and dissipated with very similar patterns.  

Water Resources Summary: Drinking Water 

Surface Water

PRZM/EXAMS modeling using the Index Reservoir (IR) and the Percent Crop
Area (PCA) adjustment was used to estimate concentrations in surface
water used as a source of drinking water.  The index reservoir
represents a watershed that is more vulnerable than most used as
drinking water sources.  It was based on characteristics of a real
watershed located in western Illinois (Jones, et al., 1998).  The index
reservoir defines a standardized watershed which is tailored for each
crop simulated by adding local soils, weather, and cropping practices to
represent a vulnerable watershed for that crop.  If a community derives
its drinking water from a large river, the estimated exposure using the
IR would likely be higher than the actual exposure.  Conversely, a
community that derives its drinking water from reservoirs smaller than
the IR and/or with minimal outflow would likely get higher drinking
water exposure than estimated using the index reservoir.  Also, areas
with a more humid climate than the modeled scenario that use a similar
reservoir and cropping pattern, would likely have higher pesticide
concentrations in their drinking water than predicted.

Transport through the reservoir is represented by a single steady flow
and does not take into account reservoir discharges and withdrawals.
This assumption will underestimate removal from the reservoir during wet
periods and overestimate removal during dry periods.  The index
reservoir scenario uses the characteristic of a single soil to represent
all soils in the basin.  Soils can vary substantially across even small
areas, however, this variation is not reflected in these simulations.  

The index reservoir scenario does not take into account pesticide or
water input from tile drainage.  Areas that are prone to substantial
runoff are often tile drained.  This may underestimate exposure,
particularly on a chronic basis (the watershed on which the IR is based
had no documented tile drainage). Additionally, EXAMS is unable to
easily model spring and fall turnover events which results in complete
mixing of a chemical through the water column. Because of this
inability, Shipman City Lake has been simulated without stratification. 
There is data to suggest that Shipman City Lake does stratify in the
deepest parts of the lake at least in some years.  This may result in
both an over and underestimation of the concentration in drinking water
depending upon the time of the year and the depth the drinking water
intake is drawing from. A full description of the Index Reservoir and
assumptions is provided in the “Guidance for Use of the Index
Reservoir in Drinking Water Exposure Assessment” available from EFED
upon request.

Development of a Percent Crop Area (PCA), watershed-based adjustment
factor for the percent of land in production for a specific crop, for
sugarbeets has not been performed.  The SAP recommended against the use
of the PCA for ‘minor’ crops because it believed that the scale of
the watershed size used to develop the PCA was too large and the
resulting PCAs would likely be highly inaccurate and not conservative. 
In the absence of a PCA for sugarbeets, a default PCA of 0.9 is
currently being used.  This is based on the highest PCA for all 8-digit
HUCs in the coterminous U.S. was selected for the default PCA.  This
value is 90 percent (0.9); representing a basin where 90 percent of the
land area is in some form of agricultural production.

Tier 2 modeling with the index reservoir and the PCA is intended for use
as a screen.  That is, the estimated concentration should be higher than
most values that occur in areas where a particular crop is grown.  A
preliminary assessment comparing monitoring data for a few chemicals to
estimates made using these methods indicate that IR/PCA estimates may
not be consistently conservative.  However, monitoring data at drinking
water facilities is sparsely available and we are unable to check the
validity for most crops against monitoring data at this time.

Additional inherent limitations in the data used to develop the PCA
include:

The conversion of county-level data to watershed-based percent crop
areas assume the distribution of the crops within a county is uniform
and homogeneous.  Distance between the treated fields and the water body
is not taken into account.

The PCA’s were generated using 1992 Census of Agriculture.  However,
recent changes in the agriculture sector from farm bill legislation may
significantly impact the distribution of crops throughout the country.
Therefore, the approach assumes that year-to-year variation in cropping
patterns are minimal, thus, have minimal impacts.

The results of the modeling are presented in Table 2 and the
pesticide-specific parameters used to model sugarbeets are provided in
Table 3.  Appendix A provides the scenario specific inputs for PRZM and
EXAMS. A brief description of the modeled site follows.

The field used to grow sugarbeets is located in Polk County, Minnesota.
The soil is a Bearden silty clay loam; a fine-silty, mixed, superactive,
frigid Aeric Calciaquolls.  The series consists of very deep, somewhat
poorly drained, moderate to slowly permeable soil that formed in
calcareous silt loam and silty clay loam lacustrine sediments. These
soils are on glacial lake plains and have slopes of 0 to 3 percent. 
Mean annual precipitation is about 18 inches. The series is of large
extent in eastern North Dakota and northwestern Minnesota.  These soils
are nearly all cropped to small grains and row crops such as sugarbeets.
The Bearden soil is characterized as a Hydrologic Group C soil.

Table 2.  PRZM/EXAMS Estimated Surface Water Concentrations (µg/L)

Agricultural Setting	

Estimated 1 in 10 Year Peak	

Estimated 1 in 10 Year Mean



Sugarbeets Grown in Minnesota	

0.42	

0.005



Table 3. Triflusulfuron-methyl Specific PRZM/EXAMS Input Parameters

Input Parameter	

Input Value	

Data Source



Hydrolysis	

pH 5: 3.7 days

pH 7: 32 days

pH 9: 36 days	

MRID 4249859



Photolysis (soil and water)	

Stable	

MRIDs 42991424; 42991426



Aerobic Soil Metabolism (T1/2) 	

Bi-Phasic: 6 days, 170 days	

MRID 42496860



Soil Adsorption Coefficient (L/Kg)	

0.41 	

MRID 42496861



Solubility (µg/L)	

110	

EFED One-Liner



Henry’s Law Coefficient (atm. m3/mole	

5.9E-10	

EFED Estimated



Vapor Pressure (torr)	

1.0E-7	

EFED One-Liner



Application Rate (kg/ha)	

0.035	

Label: UpBeet



Number of Application and Method	

2; aerial	

Label: UpBeet



Ground Water

Ground water EEC were modeled using SCI-GROW, a screening groundwater
regression model developed using data from prospective groundwater
studies submitted to the OPP in support of registration.  SCI-GROW
provides a reasonable high-end estimate of ground water concentrations
of pesticides within a defined set of fate and transport characteristics
on soils that are known to be vulnerable to pesticide leaching (high
sand content with shallow depth to groundwater).

Table 4 provides the fate inputs and ground water concentration for the
application rate and interval listed in Table 3.  The estimated EEC is
considered representative of both a peak and long-term average
concentration because of the inherent transport nature of ground water
(generally slow movement from source of contamination both laterally and
horizontally).

Table 4.  SCI-GROW Estimated Ground Water Concentrations ( µg/L)

Agricultural Setting 	

Fate and Transport Inputs	

Concentration in Ground Water (µg/L)

	

Aerobic Soil Metabolism  (T1/2) 	

Soil Adsorption Coefficient (L/Kg)

	

Sugarbeets	

170	

0.50	

0.50



REFERENCES

Faust, S.D. and O.M. Aly. 1998. “Chemistry of Drinking Water
Treatment.”  2nd Edition Revised, CRC Press LLC.  July, 1998.

Jones, R.D., S.W. Abel, W. Effland, R. Matzner, and R. Parker. 1998. 
“An Index Reservoir for Use in Assessing Drinking Water Exposures.
Chapter IV in Proposed Methods for Basin-Scale Estimation of Pesticide
Concentrations in Flowing Water and Reservoirs for Tolerance
Reassessment., presented to the FIFRA Science Advisory Panel, July 29,
1998.  http://www.epa.gov/pesticides/SAP/1998/index.htm

APPENDIX A

Table A-1 PRZM 3.12   Climate and time parameters for Minnesota
Sugarbeets.



	

Minnesota Potatoes	

	





Parameter	

Value	

Source	

Quality



Starting Date*	

January 1, 1948	

	





Ending Date*	

December 31, 1983	

	





Pan Evaporation Factor  (PFAC)	

0.760	

PIC	

good



Snowmelt Factor  (SFAC)	

0.500 cm ( K-1	

PIC	

good



Minimum Depth of

Evaporation  (ANETD)	

12.0 cm	

PIC	

good



* These values are in the RUN file rather than the INP file.



Table A-2.  Erosion and landscape parameters for Minnesota Sugarbeets.



	

Minnesota Potatoes	

	





Parameter	

Value	

Source	

Quality



USLE K Factor

 (USLEK)	

0.28 tons EI-1*	

PIC	

good



USLE LS Factor (USLELS)	

0.12	

PIC	

fair



USLE P Factor  (USLEP)	

0.50	

**	

fair



Field Area  (AFIELD)	

172.8 ha	

Index Reservoir	

good



NRCS Hyetograph (IREG)	

3	

	

good



Slope (SLP)	

3.0%	

Official Soil Description***	

fair



Hydraulic Length (HL)	

464 m	

Index Reservoir	

good



* EI = 100 ft-tons * in/ acre*hr

** P Factor represent compromise for 1 year of conventional tillage and
two years of no till.

*** OSD located at http://www.statlab.iastate.edu/soild/osd.





  Table A-3. PRZM 3.1 crop parameters for Minnesota Sugarbeets.



	

Minnesota Potatoes	

	





Parameter	

Value	

Source	

Quality



Initial Crop (INICRP)	

1	

PIC	

good



Initial Surface Condition (ISCOND)	

3	

PIC	

fair



Number of Different Crops  (NDC)	

1	

**	

fair - good



Number of Cropping Periods (NCPDS)	

36	

Standard	





Maximum rainfall interception storage of crop (CINTCP)	

0.10	

PIC	

fair



Maximum Active Root Depth (AMXDR)	

20 cm	

PIC 	

fair



Maximum Canopy Coverage (COVMAX)	

80	

PIC	

fair



Soil Surface Condition After Harvest (ICNAH)	

3	

PIC	

fair



Date of Crop Emergence

(EMD, EMM, IYREM)	

05/16	

   	

fair - good



Date of Crop Maturity

(MAD, MAM, IYRMAT)	

10/06	

	

 fair - good



Date of Crop Harvest (HAD, HAM,IYRHAR)	

10/16	

	

fair - good



Maximum Dry Weight (WFMAX)	

0.0	

PIC	

fair



SCS Curve Number (CN)	

82-91	

PIC	

fair



Manning’s N Value (MNGN)	

0.020	

PRZM Manual	

good



USLE C Factor (USLEC)	

0.18-0.43	

PIC	

fair



** P Factor represent compromise for 1 year of conventional tillage and
two years of no till.







Table A-4.  PRZM 3.1 soil parameters for Bearden silty clay  used for
sugarbeets in Polk County, Minnesota.



Parameter	

Value	

Source	

Quality



Total Soil Depth (CORED)	

100 cm	

PIC	

good



Number of Horizons (NHORIZ)	

4	

	PIC	

good



First, Second, Third, and Fourth Soil Horizons (HORIZN = 1, 2, 3, 4)



Horizon Thickness (THKNS)	

10 cm (HORIZN = 1)

08 cm (HORIZN = 2)

 54 cm (HORIZN = 3)

28 cm (HORIZN = 4)	

 PIC	

good



Bulk Density (BD)	

1.40 g (cm-3 (HORIZN = 1, 2)

1.50 g (cm-3 (HORIZN = 3)

1.80 g (cm-3 (HORIZN = 4)	

PIC	

good



Initial Water Content (THETO)	

0.377 cm3-H2O (cm3-soil (HORIZN = 1, 2)

0.292 cm3-H2O (cm3-soil (HORIZN = 3)

0.285 cm3-H2O (cm3-soil (HORIZN = 4)	

PIC	

good



Compartment Thickness (DPN)	

0.1 cm (HORIZN = 1)

1.0 cm (HORIZN = 2)

2.0 cm (HORIZN = 3, 4)	

standard	





Field Capacity (THEFC)	

0.377 cm3-H2O (cm3-soil (HORIZN = 1, 2)

0.2292cm3-H2O (cm3-soil (HORIZN = 3)

0.285 cm3-H2O (cm3-soil (HORIZN = 4)	

PIC	

good



Wilting Point	

0.207 cm3-H2O (cm3-soil (HORIZN = 1, 2)

0.132 cm3-H2O (cm3-soil (HORIZN = 3)

0.125 cm3-H2O (cm3-soil (HORIZN = 4)	

PIC	

good



Organic Carbon Content	

1.16% (HORIZN = 1, 2, 3)

0.174% (HORIZN = 4)	

PIC	

good





Table A-5.  PRZM 3.1 model state flags for modeled scenario.



Parameter	

Value



Pan Factor Flag (IPEIND) 	

0



Foliar Application Model Flag (CAM)	

2



Bulk Density Flag (BDFLAG)	

0



Water Content Flag (THFLAG)	

0



Kd Flag (KDFLAG)	

0



Drainage model flag (HSWZT)	

0



Method of characteristics flag (MOC)	

0



Irrigation Flag (IRFLAG)	

0



Soil Temperature Flag (ITFLAG)	

0



Thermal Conductivity Flag (IDFLAG)	

0



Biodegradation Flag (BIOFLAG)	

0



Erosion Calculation Flag (ERFLAG)	

4



Table A-6.  EXAMS II geometry for Index Reservoir.



	

Littoral	

Benthic	

Source



Area (AREA)	

52,609 m2	

52,609 m2	

Jones et al., 1998



Depth (DEPTH)	

2.74 m	

  0.05 m	

Jones et al., 1998



Volume (VOL)	

144,000 m3	

 2630 m3	

Jones et al., 1998



Length (LENG)	

640 m	

640 m	

estimated from map 



Width (WIDTH)	

82.2 m	

82.2 m	

estimated from map



Stream Flow (STFLO)	

Minnesota Reservoir	

12.25 m3(h-1	

0 m3(h-1	

see guidance†

†Guidance for Use of the Index Reservoir in Drinking Water Exposure
Assessments, Jones, et al. November 16, 1999.



Table A-7.  EXAMS II dispersive transport parameters between benthic and
littoral layers in the Index Reservoir.



Parameter	

Path 1*	

Source



Turbulent Cross-section (XSTUR)	

52609 m2	

Burns, 1997



Characteristic Length (CHARL)	

1.395 m	

Burns, 1997



Dispersion Coefficient for Eddy Diffusivity (DSP)**	

3.0 x 10-5	

 standard pond



* JTURB(1) = 1, ITURB(1) = 2; ** each monthly parameter  set to this
value.



Table A-8.  EXAMS II sediment properties for the Index Reservoir.



Parameter	

Littoral	

Benthic	

Source



Suspended Sediment (SUSED)	

30 mg L-1	

	

standard pond



Bulk Density (BULKD)	

	

1.85 g cm-3	

standard pond



Per cent Water in Benthic Sediments (PCTWA)	

	

137%	

standard pond



Fraction of Organic Matter (FROC)	

0.04	

0.04	

 standard pond



Table A-9.  EXAMS II external environmental and location parameters for
the Index Reservoir.



Parameter	

Value	

Source



Precipitation (RAIN)	

0 mm (month-1	





Atmospheric Turbulence (ATURB)	

2.00 km	

standard pond



Evaporation Rate (EVAP)	

0 mm (month-1	





Wind Speed (WIND)	

1 m (sec-1	

standard pond



Air Mass Type (AMASS)	

Rural (R)	





Elevation (ELEV)	

54.9 m	

USGS map



Latitude (LAT)	

39.12o N	

USGS map



Longitude (LONG)	

90.05o W	

USGS map



Table A-10. EXAMS II biological characterization parameters for the
Index Reservoir.



Parameter	

Limnic	

Benthic	

Source



Bacterial Plankton Population Density (BACPL)	

1 cfu (cm-3	

	

see text



Benthic Bacteria Population Density (BNBAC)	

	

37 cfu ((100 g)-1	

see text



Bacterial Plankton Biomass (PLMAS)	

0.40 mg (L-1	

	

standard pond



Benthic Bacteria Biomass (BNMAS)	

	

6.0x10-3 g (m-2	

standard pond



Table A-11. EXAMS water quality parameters for the Index Reservoir.



Parameter	

Value	

Source



Optical path length distribution factor (DFAC)	

1.19	

Standard pond



Dissolved organic carbon (DOC)	

5 mg (L-1	

standard pond



chlorophylls and pheophytins (CHL)	

5x10-3 mg (L-1	

standard pond



pH (PH)	

7	

standard pond



pOH (POH)	

7	

standard pond



Table A-12. EXAMS mean monthly water temperatures (TCEL) for the Index
Reservoir.



Month	

Temperature (Celsius)



January	

0



February	

1.09



March	

6.26



April	

13.21



May	

18.61



June	

23.73



July	

26.09



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ਁ砃愀϶x

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Ȁ᠍ሕᨛ"Ȇ

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¶

¶

¶

¶

¶

愀Ĥ

August	

25.04



September	

20.91



October	

14.5



November	

7.04



December	

0.99



( PAGE  1 (

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

