"This grant money enables us to move forward in a much more timely manner to replace some of our older equipment," said Jim Andoga, Austin Bridge & Road president. "As a result, we can help provide much cleaner air in the Dallas-Fort Worth area. Hopefully, our children and grandchildren will see the real benefits of the program."
As research on the health effects of air quality deepens, acceptable pollution limits will likely tighten. EPA Administrator Stephen Johnson, acting in June under a court order to review the national ozone standard, proposed reducing the allowable level from .08 parts per million averaged over an 8-hour period to .07 to .075 ppm.
A panel of outside scientific experts advising EPA unanimously recommended that the new standard be lowered to within a range from .07 to .06 ppm.
"The science clearly shows that the current standard does not adequately protect public health from the harm caused by ozone," says Arthur Marin, executive director of Northeast States for Coordinated Air Use Management (NESCAUM). "EPA recognized this shortcoming but, unfortunately, it didn't go far enough with its proposed change."
"There's not much else we can do at this point to get NOx emissions from new engines down," says Joe Suchecki, a spokesman for the Engine Manufacturers Association. "We've already got regulations in place, and they call for NOx emissions of 'near zero' by 2010."
Suchecki said EPA's revised standard "would put more pressure on states to retrofit older diesel vehicles.
"I think for most states, the major source of NOx is now mobile sources," he says, "and if they lower the standard from .08 to .07, they'll have to look harder at those older engines."
In its proposal, EPA said "mobile sources and the electric-power industry were responsible for 78 percent of annual NOx emissionsin 2004."
Glen Kedzie, environmental counsel for American Trucking Association, says the federal government doesn't have the power to mandate retrofits of older trucks, but it can designate counties as nonattainment areas for the ozone standards, forcing the states to develop plans to reduce ozone.
"They may or may not include retrofits (to diesel engines in the field)," he adds, "but that's a tool in their toolbox."
Observers with American Road and Transportation Builders Association (ARTBA) estimate the change could result in 398 to 533 new counties designated as non-attainment areas, at risk of losing highway funding.
Technologies for achieving ever-cleaner diesel power are hardly science fiction. Volvo Construction Equipment CEO Tony Helsham says the Volvo Group is spending "billions of Swedish Kronors every year" to develop hybrid drive systems, and claims that the construction-equipment company will roll out hybrid-driven wheel loaders that boast up to 50 percent fuel-consumption reduction in 2009. Roller applications, he notes, are also likely early candidates for the emissions-slashing technology.
Caterpillar's CEO, Jim Owens, said the company is testing unique combinations of low-emissions diesels and electric drives as hybrid fuel and emissions reducers. Large trucks, track-type tractors, and large wheel loaders are at the top of the development priorities. But he says Caterpillar has no timeline established for introduction of a product.
"We just have to get demand from customers to put them in place," he says.
NESCAUM's 2007 report — in the association's 40th year — speaks of the practical reality of clearing the air.
"This report is intended as a testament to the fact that cutting edge pollution-control programs and public-health protection in the Northeast have occurred in lockstep with economic development. Even as the region demanded and pursued clean air, its economy has grown impressively over the past four decades, challenging the myth that aggressive pollution-control programs stifle economic growth."
Engine manufacturers have been carrying the ball for clean air since the EPA's first diesel emissions limits went into effect in 1991. They will no doubt continue to stretch their engineering abilities in the name of cleaner air in the coming decades.
But now it is equipment professionals' turn to share the innovation load. Fleet owners have to come up with creative ways to upgrade diesel engines and reduce emissions in the field economically.
"Just as we had to change our culture and manner of thinking with regards to OSHA," says Lanham, from Williams Brothers, "the same mindset shift must occur again with the Clean Air Act."
The Running Green Series
Breathing Easier with Aftertreatment
It's Not Too Late to Sample Diesel Retrofits
Emissions Regulations Squeeze Construction Equipment Owners
Construction Races Toward Using Biofuels
Reducing and Reusing Wastes Builds Leaner Shops