  SEQ CHAPTER \h \r 1 U. S. ENVIRONMENTAL PROTECTION AGENCY

Washington, D.C. 20460	

									            OFFICE OF 

	PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES 

								

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

PC Code:  036501

DP Barcode:  347373

Date: 	November 4, 2008

MEMORANDUM

Subject:	EFED Response to Comments for Coumaphos Registration Review
Regarding Data Needed to Refine Ecological Risk Assessment.

To:		Richard Dumas, Acting Branch Chief

Wilhelmena Livingston, Chemical Review Manager 

		Mail Code: 7508P

		Special Review and Reregistration Division 

		

From:		Iwona, Maher, Chemist 

Edward Odenkirchen, Ph.D., Senior Scientist

Nancy Andrews, Ph.D., Branch Chief 

Mail Code: 7507P

		Environmental Risk Branch I

		Environmental Fate and Effects Division

The attached is EFED’s response to comments provided by the United
States Department of Agriculture, Animal and Plant Health Inspection
Service (USDA APHIS) on the Coumaphos Summary Document
(EPA-HQ-OPP-2008-0023-0003) for the Coumaphos Registration Review, dated
June 2008, regarding data needed to refine the coumaphos ecological risk
assessment.  The USDA APHIS comments are provided below, along with
EFED’s response.  The Agency would like to thank the USDA APHIS for
their comments.   

The agency requested stakeholders to answer eleven questions in order to
provide information to refine the ecological risk assessment. APHIS’
response to the questions, followed by EFED comment, is as follows:

Any current information pertaining to disposal of bio-remediated cattle
dip spent solution (i.e., dried sludge generated in the evaporation
ponds)

APHIS’ response: There are three evaporation ponds used by CFTEP
officials in Texas.

One evaporation pond is located in each of the three following cities:
Mission, Eagle

Pass, and Laredo. Due to the small amount of sediment in the Mission and
Eagle Pass evaporation ponds, it has not been necessary to dispose of
any sediment from those locations. A sample of the dried sediment from
the evaporation pond in Mission was sent to the National Veterinary
Services Laboratory (NVSL) in Ames, Iowa for testing. The test indicated
that no coumaphos was present. A small amount of dried sediment
(approximately 12 feed sacks) was cleaned out of the Laredo pit, placed
into a sack, and disposed of at an approved landfill.

In order to support APHIS’ belief that the disposal of Co-Ral used in
the CFTEP does not contribute to water contamination, APHIS would like
to take this opportunity to point to USDA’s PDP monitoring data for
finished (treated) or untreated water. In 2005 and 2006, no coumaphos
was detected in finished water or untreated water. (See attachment 4 for
relevant pages(s) or see

http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5049946 and

http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5064786 for the
full

report.)

EFED comment:  The agency agrees that the current method of
bioremediated spent dip vat disposal onto an approved landfill, as
described above, should not pose surface or/and groundwater
contamination with coumaphos.  Generally, only application to
agricultural land of a pesticide product, not an approved landfill, is
assessed by OPP.  OPP assumes that coumaphos concentration is monitored
in spent dip vat sediment, and determined to be below detection levels,
prior sediment disposed onto approved landfill to prevent coumaphos
exposure. 

2. 	Confirmation on the following label information

a. Sites of application

b. Formulations

c. Application methods and equipment

d. Maximum application rates

e. Frequency of application, application intervals, and maximum number
of applications per season

f. Geographic limitations on use

APHIS’ response:

a. Sites of application: Coumaphos is primarily used at Cattle Fever
Tick Eradication Program (CFTEP) dipping vats located throughout Texas.
Spray-dip machines and hand sprays are also used throughout the state.

b. Formulations: Co-Ral (42% coumaphos) –flowable insecticide

c. Application methods and equipment: Swim dip vats, spray-dip machines,
and hand sprays.

d. Maximum application rates: Dipping vats: 42 ounces of Co-Ral per 100
gallons of water for a final concentration of approximately 0.18-0.20%
coumaphos. Hand sprays: 64 ounces of Co-Ral per 100 gallons of water for
a final concentration of approximately 0.25-0.30% coumaphos. Spray-dip
machines: 0.25% coumaphos.

e. Frequency of application, application intervals, and maximum number
of applications per season: Every 7 to 14 days as necessary.

f. Geographic limitations on use: Product not registered in California.

EFED comment:  The use data will be utilized in the risk assessment.

3. 	Use or potential use distribution

APHIS’ response: Coumaphos is only currently being used in Texas.
APHIS believes the potential to employ coumaphos to address a cattle
fever tick outbreak beyond Texas is remote.

EFED comment:  The Agency thanks APHIS for their information.  However,
the label for the product is not specifically restrictive to the
counties and catchments described in the APHIS response.  Given the
potential for use in other areas with other catchments under varying
sediment management protocols the Agency cannot restrict risk
assessments to the APHIS described conditions at this time.  However,
should the registrant of the product negotiate a label restriction with
the Agency regarding these uses, the risk assessment could confidently
be restricted to an analysis as described by APHIS

4. 	Use history

APHIS’ response: Coumaphos had been used in the CFTEP from 1971 to
present.

EFED comment:  None.

5. 	Application timing (date of first application and application
intervals) – national, state, and county.

APHIS’ response: Animals are treated within 14 days of cattle fever
ticks being found.

Animals are treated every 7 to 14 days (the 7- and 14-day treatment is
scheduled around developmental cycle of the ticks) until the date of
pasture vacation, or the end of the quarantine period.

EFED comment:  EFED will use the provided information in estimating the
maximum number of coumaphos applications made to animals.

6. 	Usage/use information for non-agricultural uses (e.g,. direct
application to animals, bee hives)

APHIS’ response: Direct application to animals.

EFED comment: None

7. 	Directly acquired county-level usage data (not derived from
state-level data) 

Page 5

a. Maximum reported use rate from usage data – county

b. Total pounds per year – county

c. The year the pesticide was last used in the county/sub-county area

d. The years in which the pesticide was applied in the county/sub-county
area

APHIS’ response:

a. Maximum reported use rate from usage data – county: Over the last
year,

Dimmit county, Texas reported the highest use rate of Co-Ral in November

2007at 96 gallons of Co-Ral that month.

b. Total pounds per year – county: Data below is from October 2007 to
June 2008.

	

Texas County Amount of Co-Ral	Used Per Year (gallons)



Cameron

Hidalgo

Starr

Zapata

Webb

Maverick

Val Verde

Dimmit

	

58

34

182

290

98

154

94

394



c. The year the pesticide was last used in the county/sub-county area:
2008

d. The years in which the pesticide was applied in the county/sub-county
area:

Since 1971 in the CFTEP.

EFED comment:  The gallons per year per county use information will be
added to use information data for coumaphos in EFED’s risk assessment.
 EFED assumes that the presented data are complete use information of
Co-Ral product for state of Texas from October 2007 to June 2008.

8. 	Typical interval (days)

APHIS’ response: 14 days.

EFED comment: None

9. State or local use restrictions

APHIS’ response: None.

EFED comment: None

10. Ecological incidents (non-target plant damage and avian, fish,
reptilian, amphibian, and mammalian mortalities) not already reported to
the Agency

APHIS’ response: None

EFED comment: None

Monitoring data

APHIS’ response:  Samples are taken from dipping vats before and after
each treatment and are tested by NVSL for Co-Ral concentration to ensure
proper label rates are being maintained throughout the treatment
process.  In addition, APHIS CFTEP employees undergo cholinesterase
testing every 60 days.

EFED comment:  This is valuable information showing good application
practice.  In addition, EFED had in mind testing of water and/or soil
material.

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