Federal Register / Vol. 65, No. 197 / Wednesday, October 11, 2000 / Notices 60437

ENVIRONMENTAL PROTECTION

AGENCY

[OPP–00679; FRL–6743–9]

Pesticides; Drinking Water Science

Policies

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice of availability.

SUMMARY: EPA is soliciting comments

on two draft pesticide science policy

documents concerning pesticide risk

assessment in drinking water. These

documents are entitled, respectively,

‘‘Drinking Water Screening-Level

Assessments’’ and ‘‘Standard Operating

Procedure (SOP) for Incorporating

Screening-Level Estimates of Drinking

Water Exposures into Aggregate Risk

Assessments.’’ Together, these

documents describe EPA’s approach to

conducting a screening-level risk

assessment of pesticide residues in

water. This notice is one in a series of

science policy documents related to the

implementation of the Federal Food,

Drug, and Cosmetic Act, as amended by

the Food Quality Protection Act.

DATES: Comments, identified by docket

control number OPP–00679, must be

received on or before December 11,

2000.

ADDRESSES: Comments may be

submitted by mail, electronically, or in

person. Please follow the detailed

instructions for each method as

provided in Unit I. of the

SUPPLEMENTARY INFORMATION. To ensure

proper receipt by EPA, it is imperative

that you identify docket control number

OPP–00679 in the subject line on the

first page of your response.

FOR FURTHER INFORMATION CONTACT: For

‘‘Drinking Water Screening-Level

Assessment,’’ contact James Hetrick,

Environmental Protection Agency

(7507C), 1200 Pennsylvania, Ave., NW.,

Washington, DC 20460; telephone

number: (703) 305–5237; fax number:

(703) 308–6181; e-mail address:

hetrick.james@epa.gov. For ‘‘Standard

Operating Procedure (SOP) for

Incorporating Screening-Level Estimates

of Drinking Water Exposure into

Aggregate Risk Assessments,’’ contact

Catherine Eiden, Environmental

Protection Agency (7509C), 1200

Pennsylvania, Ave., NW., Washington,

DC 20460; telephone number: (703)

305–7887; fax number: (703) 308–5147;

e-mail address:

eiden.catherine@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

This action is directed to the public

in general. This action may, however, be

of interest to persons who produce or

formulate pesticides, or who register

pesticide products. Since other entities

may also be interested, the Agency has

not attempted to describe all the specific

entities that may be affected by this

action. If you have any questions

regarding the applicability of this action

to a particular entity, consult the person

listed under FOR FURTHER INFORMATION

CONTACT.

B. How Can I Get Additional

Information, Including Copies of this

Document and Other Related

Documents?

1. Electronically. You may obtain

electronic copies of this document, and

certain other related documents that

might be available electronically, from

the EPA Internet Home Page at http://

www.epa.gov/. To access this

document, on the Home Page select

‘‘Laws and Regulations,’’ ‘‘Regulations

and Proposed Rules,’’ and then look up

the entry for this document under the

‘‘Federal Register—Environmental

Documents.’’ You can also go directly to

the Federal Register listings at http://

www.epa.gov/fedrgstr/.

2. Fax-on-demand. You may request a

faxed copy of the science policy

documents, as well as supporting

information, by using a faxphone to call

(202) 401–0527. Select item 6083 for the

document entitled ‘‘Drinking Water

Screening-Level Assessments’’ and

select item 6084 for the document

entitled ‘‘Standard Operating Procedure

(SOP) for Incorporating Screening-Level

Estimates of Drinking Water Exposures

into Aggregate Risk Assessments.’’ You

may also follow the automated menu.

3. In person. The Agency has

established an official record for this

action under docket control number

OPP–00679. The official record consists

of the documents specifically referenced

in this action, and other information

related to this action, including any

information claimed as Confidential

Business Information (CBI). This official

record includes the documents that are

physically located in the docket, as well

as the documents that are referenced in

those documents. The public version of

the official record does not include any

information claimed as CBI. The public

version of the official record, which

includes printed, paper versions of any

electronic comments submitted during

an applicable comment period is

available for inspection in the Public

Information and Records Integrity

Branch (PIRIB), Rm. 119, Crystal Mall

#2, 1921 Jefferson Davis Hwy.,

Arlington, VA, from 8:30 a.m. to 4 p.m.,

Monday through Friday, excluding legal

holidays. The PIRIB telephone number

is (703) 305–5805.

C. How and to Whom Do I Submit

Comments?

You may submit comments through

the mail, in person, or electronically. To

ensure proper receipt by EPA, it is

imperative that you identify docket

control number OPP–00679 in the

subject line on the first page of your

response.

1. By mail. Submit your comments to:

Public Information and Records

Integrity Branch (PIRIB), Information

Resources and Services Division

(7502C), Office of Pesticide Programs

(OPP), Environmental Protection

Agency, 1200 Pennsylvania Ave., NW.,

Washington, DC 20460.

2. In person or by courier. Deliver

your comments to: Public Information

and Records Integrity Branch (PIRIB),

Information Resources and Services

Division (7502C), Office of Pesticide

Programs (OPP), Environmental

Protection Agency, Rm. 119, Crystal

Mall #2, 1921 Jefferson Davis Hwy.,

Arlington, VA. The PIRIB is open from

8:30 a.m. to 4 p.m., Monday through

Friday, excluding legal holidays. The

PIRIB telephone number is (703) 305–

5805.

3. Electronically. You may submit

your comments electronically by e-mail

to: opp-docket@epa.gov, or you can

submit a computer disk as described in

this unit. Do not submit any information

electronically that you consider to be

CBI.. Electronic comments must be

submitted as an ASCII file avoiding use

of special characters and any form of

encryption. Comments and data will

also be accepted on standard disks in

WordPerfect 6.1/8.0 or ASCII file

format. All comments in electronic form

must be identified by docket control

number OPP–00679. Electronic

comments may also be filed online at

many Federal Depository Libraries.

D. How Should I Handle CBI that I Want

to Submit to the Agency?

Do not submit any information

electronically that you consider to be

CBI. You may claim information that

you submit to EPA in response to this

document as CBI by marking any part or

all of that information as CBI.

Information so marked will not be

disclosed except in accordance with

procedures set forth in 40 CFR part 2.

In addition to one complete version of

the comment that includes any

information claimed as CBI, a copy of

60438 Federal Register / Vol. 65, No. 197 / Wednesday, October 11, 2000 / Notices

the comment that does not contain the

information claimed as CBI must be

submitted for inclusion in the public

version of the official record.

Information not marked confidential

will be included in the public version

of the official record without prior

notice. If you have any questions about

CBI or the procedures for claiming CBI,

please consult the person listed under

FOR FURTHER INFORMATION CONTACT.

E. What Should I Consider as I Prepare

My Comments for EPA?

You may find the following

suggestions helpful for preparing your

comments:

1. Explain your views as clearly as

possible.

2. Describe any assumptions that you

used.

3. Provide copies of any technical

information and/or data you used that

support your views.

4. If you estimate potential burden or

costs, explain how you arrived at the

estimate that you provide.

5. Provide specific examples to

illustrate your concerns.

6. Offer alternative ways to improve

the documents.

7. Make sure to submit your

comments by the deadline in this

document.

8. At the beginning of your comments

(e.g., as part of the ‘‘Subject’’ heading),

be sure to properly identify the

document you are commenting on. To

ensure proper receipt by EPA, it is

imperative that you identify docket

control number OPP–00679 in the

subject line on the first page of your

response. You may also provide the

name, date, and Federal Register

citation.

II. Background Information

On August 3, 1996, the Food Quality

Protection Act of 1996 (FQPA) was

signed into law. The FQPA significantly

amended the Federal Insecticide,

Fungicide, and Rodenticide Act (FIFRA)

and the Federal Food, Drug, and

Cosmetic Act (FFDCA). Among other

changes, FQPA established a stringent

health-based standard (‘‘a reasonable

certainty of no harm’’) for pesticide

residues in foods to assure protection

from unacceptable pesticide exposure

and strengthened health protections for

infants and children from pesticide

risks.

Thereafter, the Agency established the

Food Safety Advisory Committee

(FSAC) as a subcommittee of the

National Advisory Council for

Environmental Policy and Technology

(NACEPT) to assist in soliciting input

from stakeholders and to provide input

to EPA on the broad policy choices

facing the Agency and on strategic

direction for the Office of Pesticide

Programs (OPP). The Agency has used

the interim approaches developed

through discussions with FSAC to make

regulatory decisions that meet the new

FFDCA standard, but that could be

revisited if additional information

became available or as the science

evolved. In addition, the Agency seeks

independent review and public

participation, generally through

presentation of the science policy issues

to the FIFRA Scientific Advisory Panel

(SAP), a group of independent, outside

experts who provide peer review and

scientific advice to OPP.

During 1998 and 1999, as directed by

Vice President Albert Gore, EPA and the

U.S. Department of Agriculture (USDA)

established a second subcommittee of

NACEPT, the Tolerance Reassessment

Advisory Committee (TRAC) to address

FFDCA issues and implementation.

TRAC comprised more than 50

representatives of affected user,

producer, consumer, public health,

environmental, states, and other

interested groups. The TRAC met from

May 27, 1998 through April 29, 1999.

In order to continue the constructive

discussions about FFDCA, EPA and

USDA have established, under the

auspices of NACEPT, the Committee to

Advise on Reassessment and Transition

(CARAT). The CARAT provides a forum

for a broad spectrum of stakeholders to

consult with and advise the Agency and

the Secretary of Agriculture on pest and

pesticide management transition issues

related to the tolerance reassessment

process. The CARAT is intended to

further the valuable work initiated by

the FSAC and TRAC toward the use of

sound science and greater transparency

in regulatory decisionmaking, increased

stakeholder participation, and

reasonable transition strategies that

reduce risks without jeopardizing

American agriculture and farm

communities. The CARAT held its first

meeting on June 23, 2000.

As a result of the 1998 and 1999

TRAC process, EPA decided that the

implementation process and related

policies would benefit from providing

notice and comment on major science

policy issues. The TRAC identified nine

science policy areas it believed were key

to implementation of tolerance

reassessment. EPA agreed to provide

one or more documents for comment on

each of the nine issues by announcing

their availability in the Federal

Register. In a notice published in the

Federal Register of October 29, 1998 (63

FR 58038) (FRL–6041–5), EPA described

its intended approach. Since then, EPA

has been issuing a series of draft

documents concerning the nine science

policy issues. This notice announces the

availability of two draft science policy

documents concerning the methodology

and standard operating procedures for

conducting screening-level drinking

water assessments.

III. Summary of Drinking Water

Documents

A. Part A: ‘‘Guidance for Use of the

Index Reservoir in Drinking Water

Exposure Assessments’’

The purpose of this draft science

policy document is to provide guidance

on using the index reservoir scenario for

use in estimating the exposure in

drinking water derived from vulnerable

surfacewater supplies. Since 1996, the

Agency has been using a standard small

‘‘farm pond’’ as an interim scenario for

estimating a potential upper bound on

drinking water exposure until more

appropriate tools could be developed.

The index reservoir is being

implemented in conjunction with the

percent cropped area factor to replace

the farm pond scenario. These two steps

are intended to improve the quality and

accuracy of OPP’s modeling of high-end

drinking water exposure for pesticides.

The index reservoir is intended as a

replacement for the farm pond for use

in drinking water exposure modeling. It

is used in a similar manner to the farm

pond except that flow rates have been

calibrated for local weather conditions.

Instructions for using the index

reservoir are provided in this guidance

document. The Exposure Analysis

Modeling System (EXAMS) parameters

for the standard index reservoir are

provided in Appendix C of this

guidance document.

B. Part B: ‘‘Applying a Percent Crop

Area Adjustment to Tier 2 Surface

Water Model Estimates for Pesticide

Drinking Water Exposure Assessments’’

The current process for screening

food-use pesticides for drinking water

exposure concerns from runoff to

surface water is to run the Generic

Estimated Environmental

Concentrations (GENEEC, the Tier 1

screening model) and compare the

resulting concentration to the Drinking

Water Level of Comparison (DWLOC). If

the Tier 1 estimates exceed the DWLOC,

then the Pesticide Root Zone Model/

Exposure Analysis Modeling System

(PRZM/EXAMS, the Tier 2 screening

model) is run. When running PRZM/

EXAMS for drinking water assessments,

the current policy is to select the crop

use which is expected to result in the

Federal Register / Vol. 65, No. 197 / Wednesday, October 11, 2000 / Notices 60439

highest runoff potential (based on

application rate and method and on

crop location). With issuance of this

guidance document, OPP is changing its

Tier 2 assessment process to incorporate

the Percent Crop Area (PCA) concept.

The PCA is a generic watershed-based

adjustment factor which will be applied

to pesticide concentrations estimated for

the surface water component of the

drinking water exposure assessment

using PRZM/EXAMS with the index

reservoir scenario. The output generated

by the PRZM/EXAMS model is

multiplied by the maximum PCA

(expressed as a decimal) generated for

the crop or crops of interest. For

purposes of conducting the Tier 2

drinking water assessment, the crop of

interest would most typically be the

labeled crop use that is anticipated to

result in the greatest mass of pesticide

entering the surface water body via

runoff. Currently, OPP will apply PCA

adjustments for four major crops—corn,

soybeans, wheat, and cotton. For

pesticides applied to corn, soybeans,

wheat, and cotton, Tier 2 drinking water

exposure assessments should utilize the

appropriate index reservoir scenario and

corresponding PCA(s).

This guidance results from a May

1999 presentation to the FIFRA SAP,

‘‘Proposed Methods For Determining

Watershed-derived Percent Crop Areas

And Considerations For Applying Crop

Area Adjustments to Surface Water

Screening Models,’’ and the response

and recommendations from the panel. A

more thorough discussion of this

method and comparisons of monitoring

and modeling results for selected

pesticide/crop/site combinations is

located at http://www.epa.gov/scipoly/

SAP/1999/may/pca—sap.pdf. The SAP

did not provide guidance in a few

critical areas, such as defining ‘‘major’’

versus ‘‘minor’’ uses or what to do in

most cases where a pesticide is used on

multiple crops.

This draft science policy document

provides guidance on when and how to

apply the PCA to model estimates,

describes the methods used to derive

the PCA, and discusses some of the

assumptions and limitations with the

process.

IV. Summary of ‘‘Standard Operating

Procedure (SOP) for Incorporating

Screening-level Estimates of Drinking

Water Exposure into Aggregate Risk

Assessments’’

This draft science policy document is

the SOP for a document entitled,

‘‘Estimating the Drinking Water

Component of a Dietary Exposure

Assessment’’ (notice of availability

published in the Federal Register of

November 10, 1999, 64 FR 61346; FRL–

6389–7). It outlines the general

approach to incorporating screeninglevel estimates of drinking water

exposure into OPP’s human health

aggregate risk assessments. Specifically,

it provides:

(1) A step-by-step process for OPP

staff to follow while coordinating their

work on registration and reregistration

actions.

(2) Terms, definitions, descriptions,

and calculations for use in incorporating

estimates of pesticide concentrations in

surface water and groundwater from

screening-level models into aggregate

risk assessments.

(3) Examples of specific language that

may be used in health effects risk

assessment documents to characterize

screening-level exposure estimates for

drinking water.

(4) An appendix containing example

scenarios and calculations.

Under the procedures outlined in this

draft science policy document, the

resulting estimates of risk associated

with a pesticide in drinking water are

considered to be unrefined, high-end,

upper-bound values. However, since

many compounds can be ‘‘cleared’’ of

drinking water concerns using these

screening-level procedures, the process

saves limited resources by providing an

efficient means to determine whether a

more refined assessment of drinking

water exposure for a specific compound

is warranted. This document is an

updated version of the existing SOP for

incorporating drinking water exposure

into aggregate risk assessment and

replaces the previous SOP dated August

1, 1999 (HED SOP 99.5, 1999).

V. Questions/Issues for the Drinking

Water Screening-Level Assessment and

SOP Documents

A. Index Reservoir (Part A)

1. Is the index reservoir a suitable

replacement for the standard farm pond

for screening-level drinking water

assessments?

2. Do the process and criteria used to

select the index reservoir represent a

reasonable approach? Are there any

other criteria the Agency should

consider when we reassess the reservoir

scenario in the future?

3. There are many refinements to the

reservoir approach and its screening

approach in general. Which of these

refinements should have the highest

priority?

4. It is assumed that there is no spray

drift buffer zone around the perimeter of

the reservoir. Are there any suggestions

on how to develop a standard spray drift

buffer zone for the index reservoir?

B. Percent Cropped Area (Part B)

1. The PRZM runoff model in the

index reservoir may be limited to

watersheds of no more than 20 square

miles. Are there any suggestions in

addressing the scale limitation of the

PRZM model?

2. Is it reasonable to use a PCA

adjustment to PRZM/EXAMS modeling

for more accurate and appropriately

conservative estimates of pesticide

concentrations in surface water for

screening evaluations of drinking water

exposure?

3. Is the GIS procedure for calculating

PCA appropriate for accounting for the

portion of the watershed planted to the

crops or crops of interest?

4. A default PCA has been calculated

for cases where a defensible PCA cannot

be calculated. Is it appropriate to use a

default PCA?

C. The Standard Operating Procedure

Given the limited information

available on pesticides in drinking

water, is the approach outlined in the

SOP guidance document a reasonable

way to incorporate the available

information on pesticide concentration

in surface and ground water from

screening-level models into aggregate

human health risk assessment?

VI. Policies Not Rules

The policy document discussed in

this notice is intended to provide

guidance to EPA personnel and

decision-makers, and to the public. As

a guidance document and not a rule, the

policy in this guidance is not binding on

either EPA or any outside parties.

Although this guidance provides a

starting point for EPA risk assessments,

EPA will depart from its policy where

the facts or circumstances warrant. In

such cases, EPA will explain why a

different course was taken. Similarly,

outside parties remain free to assert that

a policy is not appropriate for a specific

pesticide or that the circumstances

surrounding a specific risk assessment

demonstrate that a policy should not be

applied.

List of Subjects

Environmental protection,

Administrative practice and procedure,

Agricultural commodities, Pesticides

and pests.

Dated: September 27, 2000.

Susan H. Wayland,

Acting Assistant Administrator for

Prevention, Pesticides and Toxic Substances.

[FR Doc. 00–25934 Filed 10–10–00 8:45 am]

BILLING CODE 6560–50–S