Low Sulfur Gasoline Testing Project during the Winter of 2005 - 2006 The Department of Environmental Conservation (DEC) and Fairbanks North Star Borough (FNSB) in December 2005 began a study to determine whether the low sulfur gas required by federal regulations will actually help reduce Carbon Monoxide during Fairbanks' wintertime temperatures. Click to read the full Gas Testing Project. * * NEW - the report is final: Tier 2 Gasoline Benefits in Alaska (SEPT 06) * *

Vehicle on a dynamometer. Photo courtesy of FNSB Vehicle Test Facility

Project Information:

In calendar year 2000, EPA issued regulations establishing lower sulfur content requirements for all gasoline and stricter tailpipe emissions standards for all passenger vehicles, including sport utility vehicles, minivans, vans and pick-up trucks. The gasoline sulfur control program is needed to support the operation of the control technologies that are being used to meet the more stringent tailpipe emission standards. Reductions in gasoline sulfur content began phasing-in during 2004. Refiners are required to meet a refinery average sulfur standard of 30 ppm beginning in 2005 and a per gallon “cap” standard of 80 ppm beginning in 2006. Refiners in certain western states, including Alaska, were allowed to delay meeting this standard until January 2007. EPA’s mobile source emission factor model, MOBILE6, estimates that the carbon monoxide (CO) benefits of the lower sulfur gasoline to be in the range of 15 – 20% for Fairbanks in 2007. These reductions represent the single largest source of CO reduction available to the community and are critical to projections of long-term attainment contained in the recently approved CO Maintenance Plan.

Other key assumptions employed in the attainment forecast include the continuation of the I/M Program and a slow but steady outlook for growth. Recent events, however, suggest that these assumptions may not be correct. The Department of Environmental Conservation (DEC) and the Fairbanks North Star Borough have committed to consider eliminating the I/M program later this decade. In addition, there is an increasing probability that a gas pipeline will be built later this decade in the vicinity of Fairbanks. The ability of the community to accommodate the growth associated with the pipeline, eliminate the I/M program and continue to attain the CO standard will depend on the accuracy of the MOBILE6 estimates of low sulfur gasoline benefits.

Concerns about the limitations of data used in EPA’s MOBILE models (versions 5 & 6) led the DEC and the Borough to jointly construct a cold temperature testing facility in Fairbanks. Several studies (e.g., extended idle, block heaters and oxygen sensor replacement) conducted at that facility have confirmed the limitations of the MOBILE model to accurately represent emissions under cold temperature operating conditions in Alaska. In light of the findings of these programs and the importance of low sulfur gasoline to Fairbanks future attainment prospects, the DEC and Borough determined that a study is needed to confirm the magnitude of the projected emission benefits during winter operation in Alaska.

Funding was secured to proceed with a study of the emission benefits of low sulfur gasoline in Fairbanks’ cold climate. A contract has been put in place to conduct the testing project, with vehicle testing occurring in January – March 2006. Sierra Research, Inc. is the contractor selected to conduct the study in Fairbanks.

Click to read the Low Sulfur Gasoline Testing Project.

If you have questions regarding the Low Sulfur Gas Testing Project, please contact: Alice Edwards, phone: 907-465-5128, email: alice.edwards@alaska.gov