On a national level, the Environmental Protection Agency has steadily increased the stringency of emission standards for heavy duty diesel engines. Standards for heavy duty trucks and bus engines that took effect for model year 2007 specifically addressed NOx, PM and NMHC (non-methane hydrocarbon) emissions. EPA is also proposing standards for fuel efficiency and greenhouse gas emissions that would also impact this sector. Non-road diesel engine emission standards were phased in beginning in 1998 to current levels (Tier 3). Standards applicable to marine and aircraft engines have also been implemented in a phase-in approach. For more information regarding federal programs, see EPA Milestones Since the Clean Air Act Amendments of 1990.
DES addresses emissions from heavy-duty diesel trucks and buses with programs to (1) limit unnecessary idling of diesel vehicles; and (2) specify opacity standards and maintenance requirements for diesel engines at Env-A 1100. DES is also pursuing emission reductions via the Diesel Emission Reduction Act (DERA) program, which allocates federal funds for states to implement grants for clean diesel projects. In addition, DES encourages and provides support to entities eligible to take part in The National Clean Diesel Funding Assistance Program.
DES is a partner in the Northeast Diesel Collaborative (NEDC), an organization comprised of EPA Regions 1 and 2 and the environmental agencies of the their respective states (the New England states and New York, New Jersey, Puerto Rico and the US Virgin Islands). NEDC lists among their priorities to retrofit, retire, and replace older diesel engines; reduce idling through the promotion of idling alternatives; promote use of clean diesel technologies in contract specifications; promote cleaner fuels beyond existing requirements; create educational opportunities for key sectors and stakeholders; and measure and assess program effectiveness. Other NEDC members include private sector companies and Northeast States for Coordinated Air Use Management (NESCAUM).
DES encourages drivers and operators of this diesel vehicles and equipment to take advantage of every opportunity to reduce emissions; to learn about ways to keep their vehicles properly maintained and running efficiently; to learn how they can reduce unnecessary emissions and save on fuel costs; to investigate alternative fuels or retrofit devices; and to learn about emerging new technologies that may someday produce zero emission vehicles.