Houston-based Waste Management (NYSE: WMI) announced today it has formed a joint venture with Linde North America to build a California plant that the companies said would be the world's largest facility converting landfill gas to liquefied natural gas.

Linde North America is part of Germany's Linde, a gases and engineering group.

The companies plan to construct the $15.5 million project at the Altamont Landfill near Livermore, Calif.

"This project has the potential to allow us to tap into a valuable source of clean energy while greatly reducing our dependence on fossil fuels," said Duane Woods, sr. VP at Waste Management.

"This will be the largest plant of its kind and we hope to break new ground by producing commercial quantities. Natural gas is already the cleanest burning fuel available for our collection trucks, and the opportunity to use recovered landfill gas offers enormous environmental benefits to the communities we serve."

The companies said they would team up to install systems to purify and liquefy the landfill gas Waste Management collects from the natural decomposition of organic waste in the landfill, expected to produce up to 13,000 gallons per day.

Pat Murphy, president of Linde North America, said, "Linde and Waste Management are joining together to clean up our environment by capturing and reusing landfill gas for vehicle fueling, and reducing greenhouse gas emissions by more than 30,000 tons per year."

The new facility is expected to start operations in 2009.