[Federal Register Volume 79, Number 90 (Friday, May 9, 2014)]
[Notices]
[Pages 26753-26754]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-10693]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPP-2013-0442; FRL-9906-48]


White Paper on Development of Community Water System Drinking 
Water Intake Percent Cropped Area Adjustment Factors for Use in 
Drinking Water Exposure Assessments; Notice of Availability

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: The Environmental Protection Agency uses computer modeling to 
estimate human exposure to pesticides in drinking water. An input 
parameter for these exposure models is the percentage of a water 
supply's watershed area to which pesticides may be applied, a metric 
which EPA refers to as the ``percent cropped area'' (PCA). Recently, 
EPA has developed delineations of watersheds for surface water intakes 
of community water systems throughout the continental United States and 
has used this dataset to develop a corresponding dataset of watershed-
specific PCAs. Development of this Community-Water System--Drinking 
Water Intake dataset is described in a draft white paper, which has 
been updated based on peer review comments. EPA is making this updated 
version available for public review and comment.

DATES: Comments must be received on or before July 8, 2014.

ADDRESSES: Submit your comments, identified by docket identification 
(ID) number EPA-HQ-OPP-2013-0442, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments. Do not submit 
electronically any information you consider to be Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute.
     Mail: OPP Docket, Environmental Protection Agency Docket 
Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC 
20460-0001.
     Hand Delivery: To make special arrangements for hand 
delivery or delivery of boxed information, please follow the 
instructions at http://www.epa.gov/dockets/contacts.html. Additional 
instructions on commenting or visiting the docket, along with more 
information about dockets generally, is available at http://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Jim Carleton, Environmental Fate and 
Effects Division (4304T), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460-
0001; telephone number: (703) 347-0335; fax number: (703) 347-8011; 
email address: [email protected].

SUPPLEMENTARY INFORMATION: 

I. General Information

A. Does this action apply to me?

    You may be potentially affected by this action if you are required 
to conduct testing of chemical substances under the Toxic Substances 
Control Act (TSCA), the Federal Food, Drug, and Cosmetic Act (FFDCA), 
or the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). 
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. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
regulations.gov or email. Clearly mark the part or all of the 
information that you claim to be CBI. For CBI information in a disk or 
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as 
CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not

[[Page 26754]]

contain the information claimed as CBI must be submitted for inclusion 
in the public docket. Information so marked will not be disclosed 
except in accordance with procedures set forth in 40 CFR part 2.
    2. Tips for preparing your comments. When submitting comments, 
remember to:
    i. Identify the document by docket ID number and other identifying 
information (subject heading, Federal Register date and page number).
    ii. Follow directions. The Agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
    iii. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    iv. Describe any assumptions and provide any technical information 
and/or data that you used.
    v. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    vi. Provide specific examples to illustrate your concerns and 
suggest alternatives.
    vii. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    viii. Make sure to submit your comments by the comment period 
deadline identified.

C. How can I get copies of this document and other related information?

    A copy of the draft white paper is available in the docket under 
docket ID number EPA-HQ-OPP-2013-0442.

II. Background

A. What action is the agency taking?

    EPA uses PCA adjustment factors to modify modeled concentrations of 
pesticides in surface waters in accordance with land cover types (i.e., 
crops) associated with a pesticide's uses. PCA-adjusted concentrations 
are used as estimated drinking water concentrations in human health 
risk assessments. Previously, PCAs were generated for Hydrologic Unit 
Code 8 (HUC-8) regions (part of a hierarchical system for classifying 
and mapping drainage areas in the United States). In this current 
update, PCAs have been generated for watersheds delineated based on 
surface-source drinking water intakes (DWI) of community water systems 
(CWSs) across the United States
    The new PCAs are an improvement over previously calculated PCAs in 
terms of their relevance to human health risk assessment because they 
were derived for known drinking water sources. Out of 6,550 DWI 
locations, which both met the selection criteria for watershed 
delineation and passed a Quality Assurance screen, 74% (4,840) had 
delineated watersheds that also passed a Quality Assurance screen. 
Summary values are presented in the draft white paper along with 
detailed descriptions of their development and suggested procedures for 
their routine use in pesticide risk assessment.

B. What is the agency's authority for taking this action?

    The Agency's authority is FIFRA (7 U.S.C. 136-136y).

List of Subjects

    Environmental protection, Community water systems, Drinking water 
exposure assessments, Health and safety, Percent cropped area, 
Pesticides and pests, Surface water intakes.

    Dated: May 1, 2014.
Donald J. Brady,
Director, Environmental Fate and Effects Division, Office of Pesticide 
Programs.
[FR Doc. 2014-10693 Filed 5-8-14; 8:45 am]
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