

[Federal Register: November 15, 2006 (Volume 71, Number 220)]
[Notices]               
[Page 66523-66524]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15no06-57]                         

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2006-0886; FRL-8242-1]

 
Draft Certification Procedures for Light-Duty Diesel Vehicles and 
Heavy-Duty Diesel Engines Using Selective Catalyst Reduction (SCR) 
Technologies for Public Comment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: EPA is requesting comment on draft guidance discussing our 
intended approach for the certification of light-duty diesel vehicles 
and heavy-duty diesel engines using selective catalyst reduction (SCR) 
systems to meet EPA emissions standards.

DATES: Comments must be received on or before December 15, 2006.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2006-0886, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 

instructions for submitting comments.
     E-mail: a-and-r-docket@epa.gov.
     Fax: (202) 566-1741, Attention Docket ID No. EPA-HQ-OAR-
2006-0886.
     Mail: Air Docket, Attention Docket ID No. EPA-HQ-OAR-2006-
0886, Environmental Protection Agency, Mailcode: 6102T, 1200 
Pennsylvania Ave., NW., Washington, DC 20460.
     Hand Delivery: USEPA, Air Docket, 1301 Constitution Ave, 
NW., Room B102, Washington, DC 20004, Attention Docket ID No. EPA-HQ-
OAR-2006-0886. Such deliveries are only accepted during the Docket's 
normal hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2006-0886. Our 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 for which 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov
.

    The http://www.regulations.gov Web site is an ``anonymous access'' 

system, which means we 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 us 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, we recommend that you include your name and other contact 
information in the body of your comment and with any disk or CD you 
submit. If we cannot read your comment due to technical difficulties 
and cannot contact you for clarification, we may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, should not use any form of encryption, and should be free 
of any defects or viruses. For additional information about our public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
 For additional instructions on submitting 

comments, go to Section I of the SUPPLEMENTARY INFORMATION section of 
this document.
    Docket: All documents in the docket are listed in the http://www.regulations.gov
 index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
for which disclosure is restricted by statute. Certain other material, 
such as copyrighted material, will be publicly available only in hard

[[Page 66524]]

copy. Publicly available docket materials are available either 
electronically in http://www.regulations.gov or in hard copy at the Air 

Docket, EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Linc Wehrly, Environmental Protection 
Agency, 2565 Plymouth Road; telephone number: 734-214-4826; fax number: 
734-214-4053; e-mail address: werhly.linc@epa.gov.

SUPPLEMENTARY INFORMATION:

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

    1. Submitting CBI. Do not submit CBI to us through http://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 that you mail to EPA, mark the outside of the disk or CD as CBI and 
then identify electronically within the disk or CD 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 rule or notice 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 
reproduced.
     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.
    3. Docket Copying Costs. You may be charged a reasonable fee for 
photocopying docket materials, as provided by 40 CFR part 2.

II. Manufacturer Guidance Certification Procedure for Light-Duty Diesel 
Vehicles Using Selective Catalyst Reduction (SCR) Technologies

A. Background

    On February 10, 2000, EPA published the Tier 2 emission standards 
for light-duty vehicles and trucks. These standards established common, 
``fuel neutral'' emission requirements for gasoline and diesel 
vehicles. They also set common standards for all passenger cars, light 
trucks, and medium-duty passenger vehicles. The Tier 2 standards allow 
emission averaging and require new vehicles to meet an average 
NOX emission level of 0.07 grams per mile (g/mi). On January 
18, 2001, EPA published a rule setting stringent new requirements for 
heavy-duty highway engines and vehicles starting in 2007. Manufacturers 
plan to meet these requirements by optimizing engine designs for low 
emissions and adding high-efficiency aftertreatment. The diesel engine 
NOX standard, which is phased-in between model years 2007 
and 2010, is 0.20 grams per brake horsepower-hour (g/bhp-hr).
    Diesel engine and vehicle manufacturers have examined the use of 
several different types of NOX reduction technologies in 
order to meet these requirements. One type of NOX reducing 
technology, selective catalyst reduction (SCR), is of particular 
interest to diesel manufacturers because it can achieve as high as 90% 
NOX conversion efficiencies. An SCR system uses a nitrogen 
containing reducing agent (usually ammonia or urea) injected into the 
exhaust gas upstream of the catalyst. The reducing agent needs to be 
periodically replenished. Without the reducing agent, the efficiency of 
the SCR catalyst drops to zero and NOX emissions can 
potentially increase substantially.
    EPA intends to issue guidance to vehicle and engine manufacturers 
to discuss our intended approach for the certification of light-duty 
diesel vehicles and heavy-duty engines using SCR systems. In advance of 
issuing this guidance, EPA is requesting comment on the various 
elements of this draft approach to ensure that the public can provide 
input to EPA regarding this issue.
    EPA has place the draft guidance document in EPA Air Docket EPA-HQ-
OAR-2006-0886. Interested parties should submit comments according to 
the guidelines described at the beginning of this notice. After fully 
considering comments received, we will issue a final guidance document.

    Dated: November 6, 2006.
Margo Tsirigotis Oge,
Director, Office of Transportation and Air Quality.
 [FR Doc. E6-19264 Filed 11-14-06; 8:45 am]

BILLING CODE 6560-50-P
