CHRIS CARLSON

Norcal Waste Systems of San Francisco has announced that its subsidiaries servicing the city — Sunset Scavenger, Golden Gate Disposal & Recycling and S.F. Recycling & Disposal — now exclusively use alternative fuels in their trucks.

Since 2002, the firms have used liquefied natural gas (LNG) in a total of five collection trucks and eight transfer trucks. In March, the rest of the firms' 385-truck fleet switched to B-20, which features 20 percent biodiesel made from vegetable oil and 80 percent low-sulfur diesel. The switch will reportedly reduce annual greenhouse gas emissions by 5,400 tons, a decrease of 21 percent.

While LNG is typically more expensive than biodiesel, a Norcal official says that using both fuels is part of finding the right combination to solve the carbon emissions problem.

“There is no single solution,” says Robert Reed, director of corporate communications for Norcal. “We live in an age of climate change and need to take a lot of environmental steps forward. One of them is using alternative fuels.”

Compared to traditional diesel trucks, LNG-fueled trucks can reduce carbon emissions by 56 percent. In 2002, Norcal built the first liquefied natural gas fueling station in the Bay Area, located in Brisbane, Calif.

“San Francisco adopted aggressive goals to reduce citywide greenhouse gas emissions,” said Jared Blumenfield, director of San Francisco's Environmental Department, in a press release. “By operating their entire truck fleet on alternative fuels, Sunset Scavenger and Golden Gate are helping to fight global warming as well as improve the quality of life in San Francisco.”