Office of Transportation                           EPA420-F-04-014
^/Cnr\         and Air Quality                                August 2004
   5nv i'miTu.ntsl Protector   	
   Agpnu
                  Regulatory
                  Announcement
                   Notice of Proposed Rulemaking to
                   Revise MSAT Default Baseline Values
                  The U.S. Environmental Protection Agency (EPA) is issuing a Notice of
                  Proposed Rulemaking to revise the Mobile Source Air Toxics (MSAT)
                  Rule default baseline values. This rulemaking also would correct an
                  error in the MSAT reformulated gasoline (RFG) default baseline value
                  published in the original rule.
                  Background
                  The final MSAT rule, published March 29, 2001 (as Control of Emis-
                  sions of Hazardous Air Pollutants From Mobile Sources), requires that
                  the annual average toxics performance level of gasoline produced or
                  imported beginning in 2002 must be at least as clean as the average
                  performance level of the gasoline produced or imported during the
                  baseline period 1998-2000. The toxics performance level is determined
                  separately for each refinery and importer, as well as separately for RFG
                  and conventional gasoline.

                  The MSAT default baseline applies to the gasoline of those parties who
                  cannot establish a unique individual MSAT baseline under the MSAT
                  rules. Such parties may not have existed during the MSAT baseline
                  period, or did not have sufficient gasoline production or import activity
                  during that period. The default MSAT baseline is an estimate of the
                  nationwide annual average toxics performance level of gasoline. At the

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time of the rulemaking, toxics performance data from calendar year 2000
was not yet available. In the final rulemaking, we committed to revise
the default MSAT baseline values once the 2000 data became available.
This rulemaking would fulfill that commitment. We are proposing that
the revised values be effective beginning with the 2005 compliance
period.

This rulemaking would also correct an error in the original rule affecting
the originally published RFG default baseline value. The correct value
would be effective for the 2002-2004 compliance periods.
Health      Environmental
The final MSAT rule set gasoline toxic emission performance standards
to ensure that refiners and importers maintain their average 1998-2000
gasoline toxic emission performance levels. This proposal to update the
default MSAT baseline values would not change the environmental
analyses discussed in the final MSAT rule.
Effect on Industry
The proposed revised conventional gasoline default baseline value is less
stringent than the current conventional gasoline value. The proposed
revised RFG default baseline value is slightly more stringent than the
current RFG value. This outcome for RFG is not unexpected as the
standards recently changed (in 2000) which increased the toxic perfor-
mance standard from 16.5 percent reduction to a 21.5 percent reduction.
Nonetheless, EPA expects this rule to have minimal economic conse-
quences.
Public  Participation Opportunities
We welcome your comments on this proposed rule. For instructions on
submitting written comments, please see the Federal Register notice,
which is available from the EPA Air Docket by calling 202-566-1742;
please refer to Docket No. OAR-2002-0042. In addition, you can access
the proposed rule and related documents on EPAs Office of Transporta-
tion and Air Quality (OTAQ) Web site at:

    www.epa.gov/otaq/toxics.htm

Additionally, if requested within 20 days of publication in the Federal
Register,  we will conduct a hearing on this proposed rule.

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For More information
For further information on this proposed rule, please contact Christine
Brunner at:

U.S. Environmental Protection Agency
National Vehicle and Fuel Emissions Laboratory
2000 Traverwood
Ann Arbor, MI 48105
(734)214-4287
E-mail: brunner.christine@epa.gov

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