United Slates
Environmental Protection
               Office of Transportation                           EPA420-F-05-028
               and Air Quality                                October 2005
               EPA Proposes Effective Date
               for Diesel Fuel Sulfur Control
               Requirements  in Rural Alaska
               The U.S. Environmental Protection Agency (EPA) is proposing to
               modify the diesel fuel regulations to apply an effective date of June 1,
               2010, for the sulfur, cetane and aromatics requirements for highway,
               nonroad, locomotive and marine diesel fuel produced or imported for,
               distributed to, or used in the rural areas of Alaska. On that date, rural
               Alaska would catch up with the implementation schedule of the rules
               that are applicable in the rest of the United States, providing the full
               environmental benefits of these programs to rural Alaska. On June 1,
               2010, all diesel fuels would have to meet a 15 parts per million (ppm)
               (maximum) sulfur content standard. This rulemaking would allow
               implementation of the nationwide programs for highway and nonroad
               diesel fuels in Alaska to be consistent with an alternative transition
               program requested by the State.
               The pollution emitted by diesel engines contributes greatly to our na-
               tion's continuing air quality problems. Even with more stringent heavy-
               duty highway engine standards that became effective in 2004, diesel
               engines will continue to emit large amounts of nitrogen oxides (NOx)
               and particulate matter (PM), both of which contribute to serious public
               health problems in the United States. Exposure is widespread, particu-
               larly in urban areas.

and Bus
Clean Air
Diesel Rule
In 2001,we established a comprehensive national control program that
will regulate heavy-duty highway vehicles and their fuel as a single sys-
tem. New emission standards will begin to take effect with model year
2007 and will apply to heavy-duty highway engines and vehicles.

These standards are based on the use of high-efficiency catalytic exhaust
emission control devices or comparably effective advanced technologies.
Because these devices are damaged by sulfur, we also reduced the allow-
able level of sulfur in highway diesel fuel by 97 percent. This reduction
to 15 ppm sulfur is required for at least 80 percent of the highway diesel
fuel beginning June 1, 2006, and the remaining diesel fuel meeting the
500 ppm sulfur standard must be segregated from the 15 ppm sulfur fuel
and used only in 2006 and earlier model year highway diesel vehicles.
Beginning June  1, 2010, all highway diesel fuel must meet the 15 ppm
sulfur standard.

Similarly, in 2004 we established a comprehensive national program to
reduce emissions from nonroad diesel engines, locomotives, and ma-
rine vessels. Engine manufacturers will produce engines with advanced
emission-control technologies similar to those upcoming for highway
trucks and buses. Closely linked to these engine provisions are new fuel
requirements that will decrease the allowable levels of sulfur in fuel used
in nonroad diesel engines, locomotives, and marine vessels by more than
99 percent.

A reduction from uncontrolled sulfur levels to 500 ppm sulfur begins
June 1, 2007, and the final reduction to 15 ppm sulfur begins June 1,
2010, for nonroad diesel fuel, and June 1, 2012, for locomotive and ma-
rine vessel diesel fuel. However,  nonroad, locomotive, or marine diesel
fuel with uncontrolled sulfur content (and uncontrolled aromatics con-
tent and cetane index) is allowed for EPA-approved small refiners and
importers. Diesel fuel that is used for other types of application, such as
heating oil, must be segregated and identified with a yellow marker and
red dye.
              Alaska under the 2001 Highway Diesel Rule
              Since the beginning of the 500 ppm highway diesel fuel program in
              1993, we have granted Alaska exemptions from both the sulfur standard
              and dye provisions because of its unique geographical, meteorological,
              air quality, and economic factors.

Under the 2001 highway diesel rule, the sulfur exemption for Alaska
terminated and required the State to meet the new low sulfur standards
taking effect in June 2006 (80% of diesel fuel meeting the  15 ppm re-
quirement). However, based on factors unique to Alaska, we provided
the State with: (1) an extension of the temporary exemption from the
500 ppm sulfur standard in the urban areas until the effective date of
the new 15 ppm sulfur standard;  (2) an opportunity to request an alter-
native implementation plan for the 15 ppm sulfur diesel fuel program;
and (3) a permanent exemption from the diesel  fuel dye provisions.
Alaska under the 2004 Nonroad Diesel Rule
Under the Agency's Nonroad Rule, engines in Alaska must meet all
emission requirements. In regards to the fuel sulfur requirements, full
implementation was applied to urban Alaska (rural Alaska would be
addressed in a separate rulemaking). In addition, rural areas of Alaska
were exempt from the segregation and dye provisions for its heat-
ing oil. This was due to the fact that 95% of the distillate fuel (diesel
+ heating oil) is used for heating oil, and only  5% for highway and
nonroad applications due to the largely subsistence economy of remote
rural areas of Alaska. While the State cannot obtain early use credits,
small refiners may apply for flexibilities if it obtains approval from the
EPA for a compliance plan.

To allow coordination between the highway and nonroad diesel sulfur
requirements in rural Alaska, the 2004 nonroad final rule deferred final
action on the fuel sulfur standards and implementation deadlines. We
indicated it would issue a supplemental proposal (i.e., this proposed
rule) to address the comments submitted by the State for nonroad die-
sel fuel in the rural areas, as well as the State's alternative implementa-
tion plan for highway diesel fuel in the rural areas. We did, however,
finalize requirements prohibiting the use of high sulfur diesel fuel
(greater than 15ppm) in model year 2011 and later nonroad engines.
Rural Alaska is Unique
Alaska requested that the nationwide diesel fuel requirements be appli-
cable to the rural areas, but not until June 1, 2010, to allow those areas
more time to develop cost effective methods to distribute and store the
low sulfur diesel fuel. Rural Alaska represents a rather unique situa-
tion. The State estimates that highway vehicles consume only about
one percent of the distillate fuel in the rural areas, while marine en-

gines consume about four percent. "Heating oil" consumes the remaining
95 percent. There is no significant consumption of nonroad or locomo-
tive diesel fuel in rural Alaska. Thus, there is only a small proportion of
the distillate fuel that we are regulating for sulfur content (and aromatics
content and/or cetane index).

Our goal is to allow Alaska to transition to the low sulfur fuel programs
in a manner that minimizes costs while still ensuring that the small
number of new vehicles and engines with high-efficiency catalytic
exhaust emission control devices, or comparably effective advanced
technologies, receive the 15 ppm sulfur diesel fuel they need. The State
did not ask for an alternative transition schedule for the urban areas, and
indicated those areas should be subject to the national implementation
schedules of the diesel fuel programs.
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-2004-0229. In addition, you can access
the proposed rule and related documents on EPA's Office of Transporta-
tion and Air Quality (OTAQ) Web site at:


A public hearing is not anticipated, but will be scheduled if requested by
the public. If a pubic hearing is requested within 30 days of publication
of this proposal, notice of the hearing will subsequently be published in
the Federal Register.
For More Information
For more information, please contact David Korotney at:

U.S. Environmental Protection Agency
Office of Transportation and Air Quality
2000 Traverwood Drive
Ann Arbor, MI 48105
E-mail: korotney.david@epa.gov