Mack Trucks has returned 125 workers to its manufacturing facilities in the Lehigh Valley. According to John Walsh, spokesman for the company, "We recently put an additional 125 or so folks to work in our Macungie Assembly Operations to support a ramp-up in production."

"While the construction market remains weak, we've recently experienced an uptick in order activity on the highway and refuse sides of our business," Walsh said.

With the return of the 125 laid-off workers, Mack Trucks will have increased their employment to approximately 875 workers. The recent high for the plant was in 2006 when employment was above 1,000.

"We have had to lay off in the neighborhood of 200 people the past couple of years," Walsh said, "but we're seeing signs of improving conditions. The recent increase in employment comes on the heels of our recall of 75 people in June."

In 2008, Mack Trucks announced a relocation of technical employees from Macungie to its corporate headquarters in Greensboro, N.C. According to Walsh, "The relocation of functions previously located in our Engineering Development and Test Center had essentially no impact on employment at the Macungie plant."

Walsh said that a factor in the 2006 employment peak was orders by the truck industry before the implementation of the 2007 EPA emissions standards. The Mack trucks which are now in production, have been engineered to meet emission standards, and in doing so, have achieved higher fuel efficiency.

Mack Trucks, a division of Sweden's Volvo AB, saw a sales increase in the first half of 2010.

"Beyond the economic and market forces at work, we're also getting a very positive reaction to our new EPA 2010-compliant trucks. These trucks meet the most stringent environmental regulations in the world-and in addition to this, they are also offering our customers better fuel economy than pre-2010 models.

Mack has introduced a new line of trucks that meet the most current emission requirements while providing improved fuel efficiency, in increase in performance that helped to offset the approximately $10,000 higher cost per vehicle for compliance.

"To meet the EPA requirements, Mack developed the ClearTech Selective Catalytic Reduction technology," Walsh noted. "Customers are experiencing up to a five percent improvement in fuel efficiency-which is a very big deal given that fuel is often their number one cost."

Mack calls the Selective Catalytic Reduction on its diesel engines as, "an emissions-reduction technology with the ability to deliver near-zero emissions of nitrogen oxides (NOx), a smog-causing pollutant and greenhouse gas. SCR's performance has been proved in millions of miles of real-world truck operations in other countries, as well as in long-term field tests in the U.S."

SCR is described as an "aftertreatment system which converts NOx in the exhaust stream into harmless gases" by injecting a controlled amount of urea solution. This Diesel Exhaust Fluid works with the heat of the exhaust and a catalyst to convert NOx into nitrogen and water vapor-a process that, Mack advertises, cleans up the emissions and improves fuel efficiency.