Despite Progress, Diesel Emissions Still an Issue for Environmental Regulators

WASHINGTON — Environmental officials from California and the East Coast said during a Transportation Research Board panel here that trucks still require special attention because of diesel emissions, even though such output became much cleaner from 1998 to 2010.

In a Jan. 11 session during TRB’s annual meeting, Matt Miyasato of the South Coast Air Quality Management District in the Los Angeles metropolitan area said California has the nation’s worst air quality, particularly in SCAQMD’s four-county area and in the San Joaquin Valley.

He said the state as a whole is concerned about carbon dioxide emissions as they relate to climate change. Densely populated areas are also concerned with nitrogen oxide compounds and particulate matter, often called criteria pollutants.

The regulatory ceiling on NOx emissions from trucks fell by 95% to 0.2 gram per unit of power in 2010 from 4.0 grams in 1998. However, Miyasato said the state wants to drive it down by another 90% to 0.02 grams within the next 20 years.

Susan Wierman of the Mid-Atlantic Regional Air Management Association said her group has raised government grant money to retire older trucks from working at the ports of Hampton Roads, Virginia, Baltimore, Wilmington, Delaware, and Philadelphia.

Wierman said the eastern ports prefer trucks with engines made in 2007 or more recently. That is the generation of engines that run on ultra-low-sulfur and that incorporate diesel particulate filters.

More recently, though, the ports have been changing to a desire for engines from 2010 or later, which use selective catalytic reduction.