Direct Final  Rulemaking Revising
Mobile Source Air Toxics  Early Credit
Technology  Requirement
    The U.S. Environmental Protection Agency (EPA) is issuing a
    direct final rulemaking to revise the February 26, 2007 mobile
source air toxics rule's requirements that specify the benzene control
technologies that qualify a refiner to generate early benzene credits.
The 2007 rule allows four benzene-reducing operational or technolog-
ical changes to fulfill the early credit technological requirement.  This
action will add another specific benzene control technology, benzene
alkylation.  This action also includes a general provision that allows a
refiner to submit a request to EPA to approve other benzene-reducing
operational changes or technologies for the purpose of generating early
credits.
Background
The Mobile Source Air Toxics rule, published on February 26, 2007, requires that
refiners and importers produce gasoline that has an annual average benzene content
of 0.62 volume percent (vol%) or less, beginning in 2011. The rule also requires that
no refiner or importer have an actual average gasoline benzene level greater than 1.3
vol%. After achieving an actual annual average benzene level of 1.3 vol%, refiners
and importers may use benzene credits to reduce their average benzene level to 0.62
vol%.

Refiners may generate  benzene credits for their own use or to sell to others, in two
ways. Once the program begins in 2011, a refiner generates credits (known as stan-
dard credits) when its average annual gasoline benzene level is less than 0.62 vol%.
(Importers can also generate standard credits.) Refiners may also generate credits pri-
or to 2011.  These credits are called early credits. In order to generate early credits, a
refinery must meet several requirements:

   1. Establish a benzene baseline based on the average benzene level of the
     gasoline produced at the refinery during the two-year period 2004-05.
United States
Environmental Protection
Agency
                                 Office of Transportation and Air Quality
                                                   EPA420-F-08-007
                                                     February 2008

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    2.  Make operational changes or improvements in benzene control technology that will
       result in real benzene reductions.

    3.  Achieve an annual average benzene level at least 10% lower than its baseline level.

In the 2007 final rule, we specified four types of operational changes and benzene control tech-
nology improvements that would allow a refinery to qualify for generating early credits if it also
met other related requirements.  These operational changes and technology improvements are:

    1.  Treating the heavy straight run naphtha entering the reformer using light naphtha
       splitting and/or isomerization.

    2.  Treating the reformate stream exiting the reformer using benzene extraction or benzene
       saturation.

    3.  Directing additional refinery streams to the reformer for treatment as described in 1) and
       2) above.

    4.  Directing reformate streams to other refineries with treatment capabilities as described in
       2) above.

We included in this list all the strategies we thought would reduce benzene and be cost-effec-
tive. The provision was intended to not allow early credit generation solely by benzene reduc-
tions achieved through ethanol blending. The final rule did not provide a way for EPA to con-
sider alternative means of reducing benzene, no matter how efficacious the  alternative might be.
Soon after the rule was finalized, it came to our attention that at least one refinery had plans to
install benzene alkylation technology. Although EPA regards benzene alkylation as a legitimate
benzene reduction technology, we did not expect it to be used.

Today's action revises the  2007 rule  to include benzene alkylation in the list of acceptable reduc-
tion operational and technological strategies.  We have also included a general provision that
would allow a refiner to petition EPA to use an operational or technological change that is not
listed in the regulation for the purpose of generating early credits.
How to Comment
This rule is being released as Direct Final Rule because we view it as a non-controversial action
and anticipate no adverse comment.  However, comments can be submitted under a parallel
Notice of Proposed Rulemaking. Comments will be accepted for 30 days beginning when this
proposal is published in the Federal Register. All comments should be identified by Docket ID
No. EPA-HQ-OAR-2005-0036 and submitted by one of the following methods:

          www.regulations.gov Follow the on-line instructions for submitting comments.
          Fax:  202-566-9744.
          Mail:             EPA-HQ-2005-0036
                           Environmental Protection Agency
                           Mailcode: 2822T
                           1200 Pennsylvania Ave. NW
                           Washington, DC 20460
Revising Mobile Source Air Toxics Early Credit Technology Requirement

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          Hand Delivery:    EPA Docket Center (EPA/DC)
                          EPA Headquarters Library
                          Room 3334 West Building
                          1301 Constitution Ave., NW.
                          Washington, DC 20004
                          Such deliveries are only accepted during the Docket's normal
                          hours of operation, and special arrangements should be made for
                          deliveries of boxed information.
For More Information
You can access documents on this rulemaking on EPA's Office of Transportation and Air Quality
Web site at: www.epa.gov/otaq/toxics.htm or contact:

                          Assessment and Standards Division
                          U.S. Environmental Protection Agency
                          Office of Transportation and Air Quality
                          2000 Traverwood Drive
                          Ann Arbor, MI 48105

                          Voicemail: 734-214-4636
                          E-mail: asdinfo@epa.gov
Revising Mobile Source Air Toxics Early Credit Technology Requirement

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