CARSON, Calif.–Waste Management added the 1,000th natural gas truck to its fleet, making it the largest owner and operator of clean-running, heavy-duty refuse trucks in North America, according to the company.

“This is a special milestone in our journey to develop the cleanest fleet of heavy-duty trucks in our industry,” said Duane Woods, senior vice president at Waste Management. “We are pleased that we have so many natural gas trucks now in service, particularly in Southern California where clean air is such a critical issue.”

The trucks that Waste Management runs out of its Carson service yard–as well as one-third of its California clean fleet–are powered by liquefied natural gas derived from the decomposition of organic waste in its Altamont Landfill in Livermore, Calif., Woods said.

Since November 2009, the landfill has been generating as much as 13,000 gallons of LNG–a virtually zero-carbon transportation fuel–per day.

In one year, Waste Management’s 1,000 natural gas trucks will displace eight million gallons of petroleum and eliminate 45,100 metric tons of greenhouse gas emissions, according to the company.

Waste Management also has CNG and LNG fueling stations at 17 of its facilities throughout North America, with more under development. Woods added that the company hopes to develop a new landfill-gas-to-LNG facility at its Simi Valley landfill.

Houston-based Waste Management was the first solid waste company to join the California Climate Action Registry, according to Woods. In 2003, the company committed to reducing greenhouse gas emissions through increased recycling, the use of alternative transportation fuels and the beneficial use of landfill gas.