In December 2003, the U.S. EPA awarded $100,000 to the Maryland Department of the Environment for a project to reduce emissions from transit buses operating throughout the Baltimore Metropolitan region. An additional amount of $39,614 was contributed by the Maryland Department of Transportation (MDOT) to complete funding. Under this project, the Maryland Transit Administration (MTA), converted the Eastern Maintenance Facility from regular diesel fuel (D2) to ultra-low sulfur diesel (ULSD) fuel.

Early introduction of ULSD on September of 2004 accomplished the primary goal of reducing volatile organic compounds (VOCs), particulate matter (PM), carbon monoxide (CO), and air toxics in a major metropolitan area and a designated Environmental Benefits District (EBD). The second goal was to obtain important experience with buying, refueling, handling, and using ULSD.

MTA’s experience with ULSD fuel at the Eastern facility was positive. There were no significant changes to bus operation, maintenance, or fuel consumption, regardless of the age of the vehicle. During the testing period, the vehicles at the Eastern Facility consumed over one million gallons of ULSD fuel; consumption per bus averaged over 900 gallons per month. There was no significant difference in fuel efficiency between using the D2 diesel and the ULSD.

Refueling at the Eastern Facility with ULSD resulted in reductions of 0.06 tons/day of VOC and 0.004 tons/day of PM. The use of ULSD reduced CO emissions by approximately 29% as compared to regular diesel fuel. Air toxics emissions were also reduced. Sulfur dioxide (SO2) and sulfate (SO4) emissions were reduced by more than 90%, and the emissions of polycyclic aromatic hydrocarbons (PAHs), widely considered to be the cancer causing component of diesel exhaust, were reduced by approximately 22%.

If you have any questions, please contact Tim Shepherd at 410-537-3270 or e-mail at tim.shepherd@maryland.gov so that he may direct your inquiry.

​