Posting an FDMS Docket without a Federal Register Notice 

MEMORANDUM 

SUBJECT: 

FROM: 

Thru: 

Posting EPA-HQ-OAR-20 I 0-1 059 to Regulations.goy ror Public Access 

Larry D. Wallace 

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L/" Jtfch~~~ Damberg 

Acting Group Leader, SLPG, AQPD 

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This memorandum authori zes the posting 0 EPA-HQ-OAR-ZOI 0- 1 059 to 

Regulations.goy for public access. 

On September 22, 2011, EPA posted its draft non-binding guidance titled, "Guidance for 

I-Hour S02 NAAQS SIP Submissions" on its website and invited public comments on 

this guidance document. As a result of the comments that EPA received on the draft 

guidance, we decided to draft a White Paper related to our current thinking on how we 

should move forward with implementation of the I-hour S02 NAAQS are seeking 

comments on the White Paper. 

The purpose of this paper is to facilitate input from states, tribes, and other interested 

stakeholders on EPA's implementation of the primary I-hour sulfur dioxide (S02) 

National Ambient Air Quality Standard (NAAQS). In particular, this paper focuses on the 

determination of whether the air quality in a given area currently meets the NAAQS. This 

determination occurs primarily in the context of designating areas as attainment, 

nonattainment, or unclassifiable; and in the context of redesignating areas from 

nonattainment, attainment, or unclassifiable to another status. EPA anticipates that some 

combination of enhanced ambient monitoring and technically credible dispersion 

modeling (the combination of which we refer to as a "hybrid approach") is likely needed 

to make this determination in these contexts. To identify a workable approach, EPA is 

soliciting stakeho lder input on how best to determine whether an area attains the S02 

NAAQS (e.g., by defining and establishing a robust, representative monitoring network 

for S02 across the country, and/or by applying an appropriate modeling approach). EPA 

is also soli citing input on how best to implement such an approach (e.g., implementation 

options and SIP timelines for areas in which violations may be identified). This paper 

addresses these topics and poses several "charge" questions intended to focus upcoming 

stakeholder discussions. 

This document will be open for public comment from OS/25/20 12 to 0612212012.] 

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-201O-1059, by one 

of the following methods: 

• www.regulations.gov: Follow the on-line instructions for submitting 
comments. 

EPA's policy is that all comments received will be included in the public docket without 

change and may be made available online at http://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 http://www.regu!ations.govore-mail. The http://www.regulations.gov 

Web site is an "anonymous access" system, whi ch 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 

http://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, avoid 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 j/www.epa.gov/epahome/dockets.htm. 

Should you have any questions regarding this memorandum, please contact Eric Shultz at 

(202) 566-1 883, or via email atschultz.eric@epa.gov.