[Federal Register Volume 74, Number 115 (Wednesday, June 17, 2009)]
[Pages 28698-28700]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-14238]



[EPA-HQ-OAR-2007-1145; FRL-8916-4]

Draft Risk and Exposure Assessment Report for Review of the 
Secondary National Ambient Air Quality Standards for Oxides of Nitrogen 
and Oxides of Sulfur

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of draft report for public review and comment.


SUMMARY: On or about June 5, 2009, the Office of Air Quality Planning 
and Standards (OAQPS) of EPA is making available for public review and 
comment a draft document titled ``Risk and Exposure Assessment to 
Support the Review of the Secondary National Ambient Air Quality 
Standards for Oxides of Nitrogen and Oxides of Sulfur: Second Draft.'' 
The purpose of this draft document is to convey the approach taken to 
assess environmental exposures to ambient oxides of nitrogen and sulfur 
and to characterize associated public welfare risks, as well as to 
present the results of those assessments.

DATES: Comments on the above report must be received on or before July 
17, 2009.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-1145, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     E-mail: Comments may be sent by electronic mail (e-mail) 
to [email protected], Attention Docket ID No. EPA-HQ-OAR-2007-
     Fax: Fax your comments to 202-566-9744, Attention Docket 
ID No. EPA-HQ-OAR-2007-1145.
     Mail: Send your comments to: Air and Radiation Docket and 
Information Center, Environmental Protection Agency, Mailcode: 2822T, 
1200 Pennsylvania Ave., NW., Washington, DC 20460, Attention Docket ID 
No. EPA-HQ-OAR-2007-1145.
     Hand Delivery or Courier: Deliver your comments to: EPA 
Docket Center, 1301 Constitution Ave., NW., Room 3334, Washington, DC. 
Such deliveries

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are only accepted during the Docket's normal hours of operation, and 
special arrangements should be made for deliveries of boxed 
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2007-1145. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through www.regulations.gov 
or e-mail. The www.regulations.gov Web site is an ``anonymous access'' 
system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through 
www.regulations.gov, your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket, visit 
the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Air Docket in the EPA 
Docket Center, EPA West, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 
p.m. Monday through Friday, excluding legal holidays. The Docket 
telephone number is 202-566-1742; fax 202-566-9744.

FOR FURTHER INFORMATION CONTACT: Dr. Anne Rea, Office of Air Quality 
Planning and Standards (Mailcode C539-02), U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711; e-mail: 
[email protected]; telephone: 919-541-0053; fax: 919-541-0840.

General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
www.regulations.gov or e-mail. 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 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:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     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.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

SUPPLEMENTARY INFORMATION: Under section 108(a) of the Clean Air Act 
(CAA), the Administrator identifies and lists certain pollutants which 
``cause or contribute to air pollution which may reasonably be 
anticipated to endanger public health or welfare.'' The EPA then issues 
air quality criteria for listed pollutants, which are commonly referred 
to as ``criteria pollutants.'' The air quality criteria are to 
``accurately reflect the latest scientific knowledge useful in 
indicating the kind and extent of all identifiable effects on public 
health or welfare which may be expected from the presence of [a] 
pollutant in the ambient air, in varying quantities.'' Under section 
109 of the CAA, EPA establishes national ambient air quality standards 
(NAAQS) for each listed pollutant, with the NAAQS based on the air 
quality criteria. Section 109(d) of the CAA requires periodic review 
and, if appropriate, revision of existing air quality criteria. The 
revised air quality criteria reflect advances in scientific knowledge 
on the effects of the pollutant on public health or welfare. The EPA is 
also required to periodically review and revise the NAAQS, if 
appropriate, based on the revised criteria.
    The EPA is currently conducting a joint review of the existing 
secondary (welfare-based) NAAQS for oxides of nitrogen (NOX) 
and oxides of sulfur (SOX). Because NOX, 
SOX, and their associated transformation products are linked 
from an atmospheric chemistry perspective as well as from an 
environmental effects perspective, and because of the National Research 
Council's 2004 recommendations to consider multiple pollutants in 
forming the scientific basis for the NAAQS, EPA has decided to jointly 
assess the science, risks, and policies relevant to protecting the 
public welfare associated with oxides of nitrogen and oxides of sulfur. 
This is the first time since NAAQS were established in 1971 that a 
joint review of these two pollutants has been conducted. Since both the 
Clean Air Scientific Advisory Committee (CASAC) and EPA have recognized 
these interactions historically, and the science related to these 
interactions has continued to evolve and grow to the present day, there 
is a strong basis for considering them together.
    As part of its review of the secondary NAAQS for NOX and 
SOX, EPA is preparing an assessment of exposures and 
characterization of risks for adverse ecological effects associated 
with atmospheric NOX and SOX deposition. A draft 
plan describing the proposed approaches to assessing ecological 
exposures and effects is described in the draft document, Draft Scope 
and Methods Plan for Risk/Exposure Assessment: Secondary NAAQS Review 
for Oxides of Nitrogen and Oxides of Sulfur. This document was released 

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public review and comment in March 2008 and was the subject of a 
consultation with the CASAC on April 2 and 3, 2008. Comments received 
from that consultation were considered in developing the document 
titled ``Risk and Exposure Assessment to Support the Review of the 
Secondary National Ambient Air Quality Standards for Oxides of Nitrogen 
and Oxides of Sulfur: First Draft,'' which was released for public 
review and comment in August 2008. This document was the subject of a 
CASAC review on October 1-2, 2008. Comments received from that review 
have been considered in developing the document titled, ``Risk and 
Exposure Assessment to Support the Review of the Secondary National 
Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of 
Sulfur: Second Draft,'' which is being released at this time.
    The second draft risk and exposure assessment for the secondary 
NOX/SOX NAAQS review released at this time 
conveys the approach taken to assess ecological effects due to the 
deposition of ambient NOX and SOX, and present 
the results of these analyses. This draft document will be available 
online at: http://www.epa.gov/ttn/naaqs/standards/no2so2sec/cr_rea.html.
    The EPA is soliciting advice and recommendations from the CASAC and 
public comments by means of a review of the draft document at an 
upcoming public meeting of the CASAC scheduled for July 22-23, 2009 in 
Research Triangle Park, NC. A separate Federal Register notice will 
provide additional details about this meeting and the process for 
participation. Following the CASAC meeting, EPA will consider comments 
received from the CASAC and the public in preparing a final risk and 
exposure assessment report.

    Dated: June 4, 2009.
Jenny N. Edmonds,
Acting Director, Office of Air Quality Planning and Standards.
[FR Doc. E9-14238 Filed 6-16-09; 8:45 am]