UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

Chemical: Fluometuron

PC Code: 035503

DP Barcode: DP 321922

Date: September 27, 2005

Subject:	Revised drinking water assessment and EFED’s Response to
Exponent, Inc “SCI-GROW Modeling for Fluometuron and Its Primary
Metabolite, Desmethyl Fluometuron; and NAWQA Monitoring Data on
Fluometuron”.

To: 		Michael Goodis, Chief

Reregistration Branch III

Special Review & Reregistration Division (7508C)

Kylie Rothwell, Risk Manager Reviewer

Reregistration Branch III

Special Review & Reregistration Division (7508C)

Elissa Reaves, Toxicologist

Samuel Ary, Chemist

Reregistration Branch II

Health and Effects Division (7509C)

From: 		Ibrahim Abdel-Saheb, Ph.D., Environmental Scientist	Signature:

Environmental Risk Branch II				Date:

Environmental Fate and Effects Division (7507C)

Reviewed 

By:		Dana Spatz, RAPL					Signature:

Environmental Risk Branch II				Date:

Environmental Fate and Effects Division (7507C)

Approved 

By:		Tom Bailey, Ph.D., Branch Chief			Signature:	

Environmental Risk Branch II				Date:

Environmental Fate and Effects Division (7507C)

Summary

This memo summarizes EFED’s revised drinking water assessment for
Fluometuron (Chemical Name [1,1-dimethyl-3-(alpha, alpha,
alpha-trifluoro-m-tolyl)urea] and its major metabolite (CGA-41686) based
on the new proposed application rates. In addition, EFED considered
Exponent, Inc documents titled “NAWQA Monitoring Data on Fluometuron
and  SCI-GROW Modeling for Fluometuron and Its Primary Metabolite,
Desmethyl Fluometuron”, dated August 1 and 12, respectively, in this
update.

Fluometuron Modeling Results

PRZM/EXAMS Modeling for Drinking Surface water 

 ADVANCE \d6 Table 1. Estimated environmental concentrations of
Fluometuron plus its degradate (CGA-41686) in surface use on cotton.







 ADVANCE \d6 	

 ADVANCE \d6 Model EECs (µg/L)



	 ADVANCE \d6 	

 ADVANCE \d6 CA	

 ADVANCE \d6 TX	

 ADVANCE \d6 MS	

 ADVANCE \d6 NC



 ADVANCE \d12 Surface water/ peak (90th percentile annual daily max.)	

 ADVANCE \d6 13.8	

 ADVANCE \d6 15.5	

 ADVANCE \d6 31.2	

 ADVANCE \d6 14.1





 ADVANCE \d6 Surface water/ 90th percentile  annual mean)	

 ADVANCE \d6 10.9	

 ADVANCE \d6 6.38	

 ADVANCE \d6 6.34	

 ADVANCE \d6 4.60





 ADVANCE \d6 Surface water/ 36-year overall mean 	

 ADVANCE \d6 9.30	

 ADVANCE \d6 3.84	

 ADVANCE \d6 2.54	

 ADVANCE \d6 3.56





 ADVANCE \d6 use(s) modeled	

 ADVANCE \d6 3 lbai/A*	

 ADVANCE \d6 2 lbai/A	

 ADVANCE \d6 3 lbai/A	

 ADVANCE \d6 2 lbai/A

 ADVANCE \d6 	

 ADVANCE \d6 Based on the revised use pattern (as described below)



	

 ADVANCE \d6 PCA	

 ADVANCE \d6 0.2



	*: Application rates used were based on soil series description in each
PRZM input file.

Sci-Grow modeling results for fluometuron and desmethyl fluometuron
following broadcast applications to cotton.

Scenario	

Fluometuron

(µg/L)	

Desmethyl Fluometuron

(µg/L)	

Fluometuron plus Desmethyl Fluometuron

(µg/L)



Light soil	12.5	9.09	21.6

Intermediate soil	18.8	13.6	32.4

Heavy soil	11.8	11.0	22.8

Soil Texture

	Max Application rate (1x)	Number of Applications	Seasonal Max. Rate
Application Interval

Sand, Loamy Sand, Sandy Loam	1 lb ai/A	2	2 lb ai/A	20 days

Loam, Silt Loam, Silt, Sandy Clay Loam, Silty clay loam, Clay loam	1.6
lb ai/A	2	3 lb ai/A	20 days

Sandy clay, Silty Clay, Clay	2 lb ai/A	2	3 lb ai/A	20 days



NAWQA Monitoring Data Characterization

NAWQA data used in this summary was based on the following to reduce
bias introduced by inclusion of counties where fluometuron historically
was not likely to have been used:

Included only those counties within states with:

High cotton area planted in 2004 (counties with >100,000 acres) (see map
in Appendix A), and 

 Historic high use of fluometuron on cotton (> 7.869 lb ai/mile2) , see
map in Appendix A.

Estimated application rate (average a.i./mile2) were relatively similar
across years for these states (Appendix A).

EPA Source data and USDA NASS data (1993-2004) (Appendix A).

NAWQA data from 1993 through 2004

GROUNDWATER NAWQA RESULTS

Arkansas

Parent

Total of 18 samples (from different wells); 7 of them were collected in
1996, and 11 in 1998.

4 samples were collected in April; and 3 in May; 3 in June; and 8 in
July.

All sites were mixed use; 

No detects in all samples (~<0.35 ppb).

TFMA

For the study period from 1993-2003; a total of 7 samples were
collected; 5 in 1996 and 2 1998. 

4 samples were collected in April, 1 sample in May, 1 in June, and 1 in
July.

Detections in all samples ( 9.91-81.0 ppb).

All sites were mixed use.



Mississippi

Parent

Total of 17 samples from different wells; 5 of them were collected in
1996, and 12 in 1998.

5 samples were collected in April, 11 in June, and 1 in July
(fluometuron is typically applied in May)

All sites were mixed use

No detects in all samples (~<0.35 ppb).

TFMA

Total of 4 samples; 3 of them were collected in 1996, and one sample in
1998.

Three samples were collected in April 1996, and one sample in July 1998.

Detections in all samples ( 40.0 - 112.0 ppb)

All sites were mixed use.

North Carolina

Parent

Total of 34 samples; 14 of them were collected in1993, 18 in 1994, and 2
in 2002.

Two were collected in February, 7 in March, 1 in May, 1 in June, 15 in
August, and 8 in September

Sites consisted of  4 mixed land use, 1 agricultural use, and 29 other
use.

Total of 3 detects ranging from 0.08 - 0.35 ppb.

TFMA

Total of 61 samples were collected; 12 in 1993, 18 in 1994, 26 in 1995,
3 in 2002, and 2 in 2003.

Seven samples were collected in mixed use areas; and 1 in agricultural
use areas; and 53 in other use areas.

Detections in all samples ( 26.3 - 0.07 ppb)



Texas

Parent

Total of 42 samples; 21 of them were collected in 2001 and 21 in 2003.

20 were collected in February, 1 in March, 15 in August, and 6 in
September

21 samples from mix land use, and 21 from agricultural land use.

Total of 2 detects (one is an estimated value of 0.0068 ppb), and the
other detect was 0.06 ppb.

TFMA

Total of 55 samples were collected; 22 samples in 2001 (in mixed use
areas), 4 in 2002 (Agricultural use areas), and 29 in 2003 (other use
areas).

Detections in all samples ( 33.6 - 288 ppb)

Summary

Groundwater monitoring data are limited spatially and temporally in
cotton and fluometuron use areas to extract useful information about
expected fluometuron concentration in drinking water in use areas.

Therefore, at this time EFED believes that at the absence of a
representative monitoring data, the use of modeling results for ground
and surface water would be more appropriate.



APPENDIX A: SOURCES OF DATA



Mississippi



Arkansas

North Carolina

Texas

	

Usage Characterization for Fluometuron 1993-2004

	Year	State	A.I. Applied Rate Range (lbs/Year)	Average A.I Application
Rate 



1993	Arkansas	650,000 - 750,000	0.5

1993	Louisiana	400,000 - 500,000	0.6

1993	Mississippi	1,000,000 - 1,250,000	0.6

1993	Texas	100,000 -150,000	0.6





	1994	Arkansas	650,000 - 750,000	0.6

1994	Louisiana	700,000 - 800,000	0.8

1994	Mississippi	1,000,000 - 1,250,000	0.6

1994	Texas	500,000 - 600,000	0.7





	1995	Alabama	400,0000 -500,000	0.8

1995	Arizona	5,000 - 10,000	0.8

1995	Arkansas	900,000 - 1,000,000	0.7

1995	Florida	50,000 - 100,000 	1

1995	Georgia	1,000,000 - 1,250,000	0.8

1995	Idaho	1,000 - 5,000	2.1

1995	Louisiana	500,000 - 600,000	0.6

1995	Mississippi	1,000,000 - 1,250,000	0.8

1995	Missouri	300,000 - 400,000	1

1995	North Carolina	550,000 - 650,000	1

1995	Oklahoma	10,000 - 15,000	0.6

1995	South Carolina	300,000 - 400,000	1

1995	Tennessee 	700,000 - 800,000	1.1

1995	Texas	350,000 - 450,000	0.8

1995	Virginia	75,000 - 100,000	1





	1996	Alabama	400,000 - 500, 000	0.8

1996	Arizona	25,000 - 50,000	1

1996	Arkansas	550,000 - 650,000	0.6

1996	Florida	25,000 - 75,000	0.7

1996	Georgia	850,000 - 1,200,000	0.8

1996	Louisiana	450,000 - 550,000	0.6

1996	Mississippi	700,000 - 800,000	0.7

1996	Missouri	250,000 - 350,000	0.8

1996	New Mexico	2,500 - 7,500	0.5

1996	North Carolina	550,000 - 650,000	0.9

1996	Oklahoma	4,000 - 6,000	0.7

1996	Pennsylvania	0-500	0.5

1996	South Carolina	200,000 - 300,000	1

1996	Tennessee	500,000 - 600,000	1.1



1996	Texas	200,000 - 300,000	0.8

1996	Virginia	85,000 - 125,000	1.1





	1997	Alabama	300,000 - 400,000	0.8

1997	Arizona	0 - 5,000	0.8

1997	Arkansas	350,000 - 450,000	0.7

1997	California	10,000 - 20,000	1

1997	Florida	20,000 - 30,000	0.7

1997	Georgia	850,000 - 1,200,000	0.7

1997	Kansas	0 - 5,000	0.5

1997	Louisiana	400,000 - 500,000	0.9

1997	Mississippi	600,000 - 700,000	0.7

1997	Missouri	150,000 0 250,000	0.7

1997	Nebraska	0 - 5,000	1

1997	North Carolina	600,000 - 700,000	0.9

1997	Oklahoma	10,000 - 30,000	0.8

1997	South Carolina	200,000 - 300,000	0.8

1997	Tennessee	450,000 - 550,000	1.1

1997	Texas	400,000 - 500,000	0.8

1997	Virginia	90,000 - 100,000	1





	1998	Alabama	200,000 - 300,000	0.8

1998	Arizona	2,500 - 7,500	0.8

1998	Arkansas	500,000 - 600,000	0.7

1998	Florida	25,000 - 35,000	1

1998	Georgia	500,000 - 600,000	0.8

1998	Kansas	0 - 5,000	1.2



1998	Louisiana	450,000 - 550,000	0.8



1998	Mississippi	600,000 - 700,000	0.8



1998	Missouri	200,000 - 300,000	1.1



1998	New Mexico	9,000 - 10,000	0.8



1998	North Carolina	250,000 - 350,000	1



1998	Oklahoma	2,500 - 7,500	1



1998	South Carolina	150,000 - 250,000	1.2



1998	Tennessee	350,000 - 450,000	1.1



1998	Texas	350,000 - 450,000	1



1998	Virginia	50,000 - 100,000	1.1







	1999	Alabama	100,000 - 200,000	0.8



1999	Arizona	2,500 - 7,500	0.5



1999	Arkansas	300,000 - 400,000	0.7



1999	California	90,000 - 100,000	2.2



1999	Florida	0 - 5,000	1



1999	Georgia	350,000 - 450,000	0.7



1999	Kansas	10,000 - 15,000	1.1



1999	Louisiana	250,000 - 350,000	0.7



1999	Mississippi	650,000 - 750,000	0.7



1999	Missouri	100,000 - 200,000	0.6



1999	North Carolina	300,000 - 400,000	0.9



1999	Oklahoma	2,500 - 7,500	0.7



1999	South Carolina	100,000 - 200,000	1



1999	Tennessee	250,000 - 350,000	0.9



1999	Texas	300,000 - 400,000	0.9



1999	Virginia	50,000 - 100,000	0.9







	2000	Alabama	100,000 - 200,000	0.8



2000	Arizona	0 - 5,000	0.8



2000	Arkansas	300,000 - 400,000	0.7



2000	Florida	10,000 - 15,000	1



2000	Georgia	200,000 - 300,000	0.8



2000	Kansas	25,000 - 50,000	1.4



2000	Louisiana	250,000 - 350,000	0.7



2000	Mississippi	400,000 - 500,000	0.7



2000	Missouri	100,000 - 200,000	0.6



2000	North Carolina	350,000 - 450,000	0.9



2000	Oklahoma	0 - 5,000	1



2000	South Carolina	50,000 - 100,000	0.9



2000	Tennessee	85,000 - 125,000	0.9



2000	Texas	250,000 - 350,000	0.8



2000	Virginia	50,000 - 100,000	1







	2001	Alabama	35,000 - 55,000	0.8



2001	Arkansas	150,000 - 250,000	0.6



2001	Florida	0 - 5,000	1



2001	Georgia	100,000 - 200,000	0.7



2001	Louisiana	100,000 - 200,000	0.8



2001	Mississippi	200,000 - 300,000	0.7



2001	Missouri	50,000 - 100,000	0.7



2001	New Mexico	0 - 5,000	1



2001	North Carolina	150,000 - 250,000	0.8



2001	Oklahoma	0 - 5,000	1



2001	South Carolina	25,000 - 75,000	0.9



2001	Tennessee	50,000 - 100,000	0.7



2001	Texas	250,000 - 350,000	0.8



2001	Virginia	25,000 - 75,000	0.9







	2002	Alabama	10,000 - 30,000	0.7



2002	Arizona	2,500 - 7,500	0.9



2002	Arkansas	100,000 - 200,000	0.6



2002	Georgia	50,000 - 100,000	1



2002	Louisiana	25,000 - 75,000	0.6



2002	Mississippi	150,000 - 250,000	0.8



2002	Missouri	50,000 - 100,000	0.6



2002	New Mexico	0 - 5,000	0.4



2002	North Carolina	100,000 - 200,000	0.9



2002	Oklahoma	0 - 5,000	0.8



2002	South Carolina	50,000 - 100,000	0.7



2002	Tennessee	25,000 - 75,000	0.6



2002	Texas	150,000 - 250,000	0.8



2002	Virginia	20,000 - 50,000	0.9







	2003	Alabama	25,000 - 75,000	0.8



2003	Arkansas	50,000 - 100,000	0.6



2003	Georgia	25,000 - 75,000	0.8



2003	Kansas	0 - 5,000	1.5



2003	Louisiana	25,000 - 75,000	0.9



2003	Mississippi	50,000 - 100,000	0.6



2003	Missouri	25,000 - 50,000	0.6



2003	North Carolina	75,000 - 100,000	1



2003	Oklahoma	0 - 5,000	0.4



2003	South Carolina	25,000 - 50,000	0.8



2003	Tennessee	25,000 - 50,000	0.7



2003	Texas	150,000 - 250,000	0.9



2003	Virginia	10,000 - 30,000	1.3







	2004	Alabama	50,000 - 100,000	0.9



2004	Arkansas	10,000 - 30,000	0.5



2004	Georgia	50,000 - 100,000	0.9



2004	Kansas	7,500 - 15,000	0.8



2004	Louisiana	25,000 - 50,000	0.8



2004	Mississippi	150,000 - 250,000	1.2



2004	Missouri	5,000 - 15,000	0.9



2004	North Carolina	25,000 - 50,000	1



2004	South Carolina	25,000 - 75,000	0.6



2004	Tennessee	50,000 - 100,000	1



2004	Texas	150,000 - 250,000	1



2004	Virginia	5,000 - 15,000	0.8







	Source:	EPA Source data and USDA NASS data (1993-2004)

	* Ranges have been given to protect proprietary data. 

	All figures have been rounded and averaged where ever possible

	

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